Class. Book. 3 \- ZDD .Mg5 GojjyriglitK? {9Z?_ COPYRIGHT DEPOSIT, The Technical Control of Dairy Products THE TECHNICAL CONTROL 0/ DAIRY PRODUCTS A Treatise on the Testing, Analyzing, Standardizing and the Manufacture of Dairy Products By Timothy Mojonnier, M. S. President Mojonnier Brothers Company Milk Engineer Consulting Chemist for Dairy Industries and Hugh Charles Troy, B.S.A. Professor of Dairying, in charge of Testing in the Department of Dairy Industry Cornell University, Ithaca, New York Consulting Chemist for New York State Department of Farms and Markets Formerly State Chemist, New York FIRST EDITION Published by MOJONNIER BROS. CO. Milk Engineers CHICAGO, ILLINOIS 1922 Copyright, 19^2, by Mojonnier Bros. Co. Copyright, 1922, in Great Britain and other countries. All rights reserved. FRED KLEIN CO, PRINTERS CHICAGO OCT 10 '2? IC1A686421 To all who are interested in the progress of the dairy industry, in its varied branches, this book is dedicated. Preface IN THE compilation of this book, the authors have endeavored to systematize and present a large amount of original in- formation and data, in such a way as to make it of the greatest value to teachers, students, plant operators, chemists and dairy control agencies. Some of the material has already appeared in addresses, and technical papers, but the larger part has not hereto- fore appeared in print. The diagrams and standardizing tables shown in Chapters X to XIV inclusive, have been developed in connection with and used for some time, with Mojonnier stand- ardizing equipment, and in instruction work. They are incorporated in this book with the hope that a larger number may profit by their proven merit and utility. Drawings and tables largely based upon original data are used frequently to make more clear the operation and application of several new methods and appliances for testing and controlling dairy products. The numerous graphs shown have been drawn from tabulated results of carefully planned and executed experiments, some of which have covered a period of several years. It is realized that there are many milk plant practices upon which opinions differ, but the aim in this book is to present facts and methods that have proven in actual practice to possess the greatest merit. Constructive criticisms or suggestions that readers may be prompted to make will be greatly appreciated. Acknowledgment of other sources of information as far as ])ossible is made in the text. Special credit is due to Mr. J. A. Cross for conspicuous services as mentioned in several places in the text ; to Mr. W. O. Frohring for valuable suggestions in connection with Chapter XVI, as well as for arranging for the loan of numerous valuable graphs and photomicrographs from the Telling-Belle- Vernon Co. ; to Mr. O. W. Mojonnier for valuable suggestions in connection with Chapter XIX ; to Mr. Roscoe Moon for help and co-operation in the preparation of illustrations and in proof reading; X PRKI'ACE to the Fred Klein Co., Chicago, 111., for excellent co-operation in all matters pertaining to the printing of the book, and to Mr. H. J. lyiedel for careful aid in many ways. Credit is further due to Mv. J. J. Mojonnier. Miss Lucy Klein, Mr. E. C. Jensen, Mr. Len Fortney, Mr. H. O. Buhrman, and others connected with Mojonnier Bros. Co. Acknowledgment is also made of courtesies extended by Mr. Mark Shanks of the Standard Ice Cream Co., Chicago, and Mr. Mark Goodman, of the Goodman- American Ice Cream Co., Chicago. Till' Authors. Contents CHAPTER I 1-9 The Dairy Plant Laboratory: Location; Floor; Ventilation; Temperature; Tables and desks; Hood; Sinks; The microscope; Steam and electricity; Lighting; Apparatus; General plans for dairy laboratories. CHAPTER II 10-33 The Constituents of Milk: General statements; The physical properties of milk; The composition of milk; Variations in content of fat and solids not fat; Distribution of constituents; Gases; Water; Total solids; Solids not fat; Milk fat; Casein; ililk sugar, solubility, crystalline condition, uses; Albumin; Mineral constituents; Lecithin; Vitamines; Citric Acid. CHAPTER III 34-61 History and Principles of Fat and Total Solids Tests: Various fat tests; The Mojonnier milk tester; Reagents used in the Mojonnier Milk Fat test, their functions; Results of comparative fat tests by Mojonnier and other methods; Proofs of accuracy of fat tests by Mojonnier method; Total solids and moisture tests; ^lojonnier total solids and moisture tests. CHAPTER IV 63-69 Assembling the Mojonnier Milk Tester: Its different parts, their uses. CHAPTER V 70-79 Preliminary Instructions for Operating the Mojonnier Milk Tester: Care to give the tester; Care and use of the balance; Influence of temperature upon results obtained in weighing; Care to give power unit, water circulating imit, vaciuim ovens, cooling ovens; Turning on the current; Heating, weigh- ing and cleaning fat and solids dishes. [xil xii Contents CHAPTER VI 80-92 Sampling Dairy Products: Sampling milk ami cream; Composite sam- ples, preservatives, care, preparation and testing; Sampling whole milk for making evai)orated and sweetened condensed milk; Sampling skim-milk, evaporated milk, sweetened condensed milk, ice cream mix, ice cream, butter, buttermilk, cheese, whey, powdered milk products, malted milk, milk chocolate, cocoa. CHAPTER VII 93-119 Directions for Making Fat Tests, Using the Mojonnier Milk Tester: Weighing the samples; Adding the reagents; ^Jixing milk and reagents; Pouring of!" the ether solution; Evaporating the ether solution; Weighing the fat dish; Recording results and calculating percentages; Running blanks upon reagents; Testing for fat, milk, skim-milk, whey, buttermilk, evapor- ated milk, condensed buttermilk, sweetened condensed milk, ice cream, cream, malted milk, chocolate, cocoa, butter, skim-milk powder; Order of operations in testing evaporated milk for fat and total solids with the ilojonnier tester; Precautions; Causes for high tests; Causes for low tests. CHAPTER VIII 120-129 Directions for Making Total Solids Tests, Using the Mojonnier Milk Tester: Outline of method; Weigliing samples for fat and solids tests; Treatment given dishes during the evaporation of moisture; Cooling and weighing the solids dishes; Calculating percentage of solids; Testing for total solids, whole milk, skim-milk, whey, buttermilk, evaporated milk, unsweetened and sweet- ened condensed milk, condensed buttermilk, ice cream mix, cream, malted milk, milk chocolate, cocoa, clieese, butter, skim-milk powder, whole milk powder, buttermilk powder; Causes of too high solids tests; Causes of too low solids tests. CHAPTER IX 130-141 General Information on Standardizing Dairy Products: Standardization defined; Steps involved; Obtaining samples and weights; Methods to use in testing and calculating results; Order of operations; Principles of calculations involved. CHAPTER X 142-161 Calculations for Standardizing Whole Milk and Cream: Standardizing for fat; The use of various products; Standardizing for both fat and solids; Problems met in standardizing milk and cream; Problems worked out in detail. Contents xm CHAPTER XI 163-319 Standardizing Evaporated Milk: Successive steps in standardizing before condensing; Constants for evaporated milk; Order of operations in standardiz- ing; Recording standardizing data; Obtaining weight of the finislied batch; Calculating the point at which to strike the batch; Relation between tempera- ture and specific gravity; Relation between specific gravity and composition; Calculation of Baume reading at any desired condensation; How to strike the pan batch; Holding tanks; Standardizing tables; Key to standardizing formu- las; Problems in standardizing evaporated milk both before and after con- densing and methods for solving them. CHAPTER XII 220-371 Standardizing Sweetened Condensed Milk: Successive steps; Methods of sampling; Testing; Order of operations; Recording data and obtaining weights; Striking the batch; Relation between specific gravity and composi- tion; Improved method and equipment; The use of tables in shortening calcu- lations; Key to formulas; Problems in standardizing before condensing and methods for solving them; Tables for ascertaining sugar required. CHAPTER XIII 273-432 The Composition and Standardization of Ice Cream Mixes: Suggested composition; Physical and chemical properties; Composition ratios; Nutritive ratios; Commercial factors as influenced by composition; Functions of the various constituents; Relation of gelatin to the incorporation of air; Sources of supply of ingredients ; Name and description of flavors, fruits and nuts used in ice cream and sherbet; Relation of composition to ice cream defects; Sandy ice cream, its cause and prevention, influence of sugar crystals, pasteurization, composition, overrun, solubility of milk sugar on sandiness; Influence of sugar and gelatin; Standardization, steps involved; Method of compounding, Order of operations; Kinds of problems encountered in standardizing; Key to factors in formulas; Problems in standardizing and methods for solving them; Use of unsweetened condensed skim-milk in ice cream mix; [Methods of calcu- lations for using sweetened condensed skim-milk; Tables for calculating the amount of sweetened condensed skim-milk and how to use them; Proofs of accuracy of tables; Compounding ice cream mixes of various tests from vari- ous products; Methods of calculations for deriving ingredient formulas; Ta- bles giving mixes of various compositions. CHAPTER XIV 433-442 The Standardization of Miscellaneous Dairy Products: Unsweetened con- densed milk, milk powder, chocolate, cocoa and milk cliocolate. xiv CONTKNTS CHAPTER XV 443-475 The Overrun in Ice Cream: General facts regarding overrun; Different pliases in freezing and liardening ice cream; Proper overrun; Composition; Aging; Acidity; Viscosity of the mix; Homogenizing and drawing the mix into the freezer; Type of freezer; Brine temperature; Control of freezing operation; Pvctaining the overrun; Relation of gelatin to overrun; The Mo- jonnier Ice Cream CHerrun Tester; Setting up and applying the Mojonnier Overrun Tester; Standardizing the overrun; Determining the overrun in ice eieanr containing crushed fruits. CHAPTER XVI 476-553 Microscopical and Bacteriological Tests of Dairy Products with Directions for the Care and Use of Cultures: The microscope in the dairy industry; Microscopical examination of fat in dairy products; Bacteria in milk; Patho- genic bacteria in milk; Bacteria producing acid but no gas; Acid gas pro- ducers; Common types of fungi found in milk; Quantitative determinations of milk organisms; Collection of samples for bacteria counts; JNIicroscopic colony count; Standard methods of bacterial milk analysis; Microscopic count of bacteria (Breed method); Verification and researcli methods; Detection of specific pathogens in milk; Commercial applications of bacteria to dairy prod- ucts; Apparatus designed to propagate pure cultures; Description of the i\iojonnier Culture Controller and Sterilizer used with the ^Mojonnier Culture Controller; Propagation of cultures and summary of directions for operating the Mojonnier Culture Controller; The application of pure cultures in the manufacture of buttermilk; pot cheese, baker's cheese, cheddar cheese and butter. CHAPTER XVII 554-683 Analysis and Miscellaneous Tests of Dairy Products: Specific gravity de- terminations; Lactometers; Formulas for calculating milk solids; Baume and Twaddell hydrometers; Calculating percentages of adulteration by skimming and watering; Determining viscosity; The Mojonnier-Doolittle viscosimeter and directions for operating it; Casein determination and tests; Nitrogen determination by Kjeldahl-Gunning method; Determining quality of casein; Determining percentages of albumin, milk sugar, sucrose, in dairy products; Qualitative tests for sucrose; Relative solubility of milk powders; Determin- ing lecithin and citric acid; Standard solutions; Acid tests; Alcohol test; Tests for preservatives, gelatin, added color; Butter analysis; Cheese analysis; Melting point of milk fat; Detecting foreign fats: Reichert-Meissl number; lodin number; Detecting giuns and thickeners; Analyzing salt; Analyzing vanilla extract, gelatin, gum arabic, gum tragacanth; Specific heat and freez- ing point of dairy products and their determination; Preparation of pure milk constituents; Hydrogen ion concentration and its electrolytic and colorimetric determination. CoNTKNTS XV CHAPTER XVllI 0S4-7 18 The Purpose and Advantage of the Vacuum Pan in the Dairy Industry: Description of the vacuum pan; Tlie vacuum pump; Tlie steam piping; Eola- tion of condenser water required to water evaporated; Steam required to con- dense milk; Relation of gas, oil and coal to steam production; Calculating the water, steam and fuel required; Operating tlie vacuum pan; forewarming milk, starting and controlling the evaporation, striking and finishing tlie batch, superheating the batch; Precautions in pan operation, condition of heating surfaces, air leaks; Influence of bicarbonate of soda; Cleaning the pan; Entrainment losses; Sweetened condensed whole milk and skim-milk, forewarming, operating the pan, striking the batcli; Condensing other liquid dairy products. CHAPTER XIX 719-771 Evaporated Milk: Its Sterilization and Physical and Chemical Control: Sterilizing; The ]Mojonnier Evaporated Milk Controller; Factors that influ- ence tlie coagulating point; Steam distribution in the sterilizer; Standardiza- tion of fat and total solids; Sodium bicarbonate solution and its use; Prepar- ing, sterilizing and cooling sample cans; Testing sample cans for viscosity and color; Adding sodium bicarbonate before sterilizing; Adjusting sterilizing records upon different sizes of cans; Changing temperature of heating in hot wells; Failure to react with sodium bicarbonate; Reducing amount of bicar- bonate; Seasonal variations in the coagulating point; Efi'ects of sterilizing temperatures upon nitrogenous constituents; Changes in viscosity at various stages of manufacture; The function of shaking and its influence upon the viscosity; Resterilization and its influence on viscosity; Detection of spoils; Factors influencing the quality; Factors influencing the color; Acidity in the various stages of manuf actvu'e ; Influence of freezing temperatures; Viscosity as related to feathering or curdling; Effect of cooling on color and viscosity; Gases in evaporated milk cans. CHAPTER XX 722-80'J Score Cards for the Dairy Industry: Development of the score card; Milk inspection question sheet; Score cards for sanitary inspection of farms, milk distributing plants, stores; Veterinarian's score card; Score cards for certified milk, milk, skim-milk, cream, butter, culture, buttermilk, cheese, cottage cheese, Swiss cheese, limburger cheese, ice cream, condensed whole milk and skim-milk, evaporated milk and powdered milk products. CHAPTER XXI 810-848 Definitions and Standards for Dairy and Related Products: Standards of the United States Department of Agriculture for dairy products, sugar, cocoa products and flavoring extracts; State standards for composition; State standards for bacteria; Statistics on milk and cream regulations in cities and towns; Grading milk and cream. xvi Contents CHAPTER XXir 84'J-8(34 Miscellaneous Information Regarding Dairy Products: Flow sheets; Temperatures for holding, manufacturing and storing; Action of milk on metals and certain properties of metals and alloys; Action of condensed and evaporated milk upon tin and iron; Heat transmission of metals, alloys and glass. APPENDIX 8G5-888 Constants of the Elements; Conversion of degrees centigrade to degrees Fahrenheit, or vice versa; Specific gravity corresponding to degrees Baume for liquids lighter than water and liquids lieavier than water; Degrees Twaddell with corresponding specific gravity; Properties of saturated steam; Converting U. S. weights and measures cvistomary to metric; Metric to customary; Miscellaneous equivalents of metric weights and measures; Equivalents of metric weights and British Imperial weights and measures, metric to Imperial and Imperial to metric; Alcohol tables; Capacities of cylindrical tanks; Composition of different mamalian milks. Index of Proper Xames 82>. Fig. 34. Fig. 35. Fig. 36. Fig. 37. Fig. 38. Fig. 39. Fig. 40. Fig. 41. Fig. 42. Fig. 43. Fig. 44. xviii Illustrations Fig. 45. Dividing line before and after raising in fat extraetion flask. . 100 Fig. 46. I'^vaporating the ether 101 Fig. 47. Transferring dishes to vacuum oven 102 I'^ig. 48. Placing dish upon the balance pan 102 Fig. 49. Valve handles controling vacuum in fat and solids ovens... 103 Fig. 50. I'^illing water tank in Mojonnier Milk Tester 104 h'ig. 51. I'^illing vacuum pump with oil 104 Fig. 52. Placing calcium chloride in cooling desiccators ; . . . 104 Fig. 53. Laboratory report blank 105 Fig. 54. Solids dish 120 Fig. 55. Weighing the solids sample 121 Fig. 56. Dish contact maker 122 Fig. 57. Cross diagram method for standardizing cream 148 Fig. 58. Cross diagram method for standardizing milk 149 Fig. 59. Fvaporated milk laboratory report 168 Fig. 60. Blank report for evaporated milk 169 Fig. 61. Green Gauge 171 Fig. 62. Specific gravity of ice cream mixes at different temperatures and for different compositions 177 Fig. 63. Pan striker for attaching to the waist of the pan 178 Fig. 64. Pan striker for attaching to outlet of pan 178 Fig. 65. Hydrometer cylinder 175 Fig. 66. P)aumc hydrometer 179 Fig. 67. Jacketed copper tank. 180 Fig. 68. Glass enameled tank 181 Fig. 69. Blank report for sweetened condensed milk 225 Fig. 70. Specific gravity of sweetened condensed milk at various tem- peratures and compositions 228 Fig 71. Relation of specific gravity and composition in sweetened condensed skim-milk at various temperatures 232 Fig. 72. Pycnometer cup 233 Fig. 73- I'.quipment for making sweetened condensed milk using Mojonnier process 235 I""ig. 74. ]\Iilk sugar crj'stals in sweetened condensed milk of good crystalline quality 236 Fig. 75. Milk sugar crystals in sweetened condensed milk of poor crystalline quality 236 Fig. 76. Sweetened condensed milk cooler 237 Fig. 77. Sweetened condensed milk cooler 237 Fig. 78, Sweetened condensed milk cooler 238 Fig. 79. Scale showing relative diameters of smooth and coarse texture water crystals '. 300 Fig. 80. Per cent of frozen crystals 300 Fig. 81- vSpecific gravity of various compositions of ice cream mix at different temperatures 304 Fig. 82. Tee cream mix and cost report 307 Fig. 83. Ice cream batch mixer 308 Fig. 84. Ice cream batch mixer 308 Fig. 85. Ice cream batch mixer 309 Fig. 86. Ice cream batch mixer 309 Fig. 87. Tee cream holding tank 309 Fig. 88. Ice cream batch mixer 310 Fipf. 89. Fig. 90. Fig. 91. Fig. 92. Fig. 93. I'ig. 94. Fig. 95. Fig. 96. Fig. 97. Fig. 98. Fig. 99. Fig. 100. Fig. 101. Fig. 102. Fig. 103. Fig. 104. Fig. 105. Fig. 106. Fig. 107. Fig. 108. Fig. 109. Fig. 110. Fig. 111. Fig. 112. Fig. 113. Fig. 114. Fig. 115. Fig. 116. Fig. 117. Fig. 118. Fig. 119. Fig. 120. Fig. 121. Fig. 122. Fig. 123. Fig. 124. Fig. 125. Fig. 126. Fig. 127. Fig. 128. Fig. 129. Fig. 130. Fig. 131. Il,IvUSTR.\TIONS XIX Diagram showing graphic method of standardization 418 Relation temperature, specific gravity and compositon in condensed whole milk 436 Relation temperature, specific gravity and composition in condensed skim-milk .■;■■■■.■ '^ Relation temperature, specific gravity and composition in condensed buttermilk 438 The four phases in the normal freezing of ice cream 444 Influence of composition upon the freezing of ice cream... 448 Influence of the sugar content of the mix upon the overrun in ice cream 450 The mfluencc of aging upon the overrun in ice cream 451 Manton-Gaulin Homogenizer 453 Progress Homogenizer 454 Viscolizer 455 Suggested location of Mojonnier Overrun Tester in the freezer room 464 Removing wire and rod from scale beam of overrun tester 466 Leveling scale on overrun tester 466 Filling dash pot w'ith oil 466 Dash pot in cross section 467 Adjusting movement of pointer 468 Phantom view of scale 469 Adjusting the overrun cup for any composition of mix.... 470 Fmptying overrun cup into freezer hopper 471 Adjusting telescopic bottom upon overrun cup 471 Filling overrun cup with ice cream at the freezer 472 Scraping overrun cup level full of ice cream 473 Making reading for overrun 473 Blank for recording overrun readings 474 Microscope with names of various parts 477 Microscopic substances found in milk 486 Bacillus subtilis 495 Bacillus subtilis with spores 495 Streptococcus lacticus 524 The relation between time of incubation and acid develop- ment in the growth of culture 526 Influence of quantity of culture used upon acid develop- ment in media ^-^ Increase in titratablc acidity, using 15 cc. and 40 cc. of cul- ture to 750 cc. of media 528 Influence of holding temperature of cultures upon the growing qualities of the same ^30 Mojonnier Culture Controller 532 Mojonnier Culture Controller in cross section 533 Sterilizer to be used with Mojonnier Culture Controller... 534 Culture jar 537 Culture pipette 539 Buttermilk machine 544 Buttermilk machine 545 Pfaudler buttermilk machine 546 Buttermilk machine 547 XX Illustrations Specific gravity chainomatic balance 554 Specific gravity bottle 555 Sprengal tube 556 Westphal balance 557 Quevenne lactometer 558 Baume hydrometer 558 N. Y. Board of Health lactometer 559 Relation between B. of H. lactometer, Quevenne lactometer and speciiic gravity scales 560 Mojonnier-Doolittle Viscosimeter 567 Mojonnier-Doolittle Viscosimeter dial 568 Tube for Hart casein test 569 Kjedahl apparatus for single nitrogen determination 571 Polariscope and tube for sugar solution 589 Nafis acidity tester 601 Wizard sediment tester 605 Wisconsin sediment tester 605 Troy salt test apparatus 615 Hunziker salt test apparatus 617 Troy moisture tester for cheese 623 Melting point apparatus 625 Abbe-Zeiss Refractometer 627 Distilling apparatus 629 Lovibond Tintometer 645 Specific heat determination apparatus 651 Specific heat of several dairy products 654 Hortvet Cryoscope 658 Casein coagulating apparatus 661 Apparatus for making electrometric titrations of solutions containing protein 675 60. Pounds of water evaporated per hour per square foot of heating surface 686 Mojonnier type vacuum pan 687 Straight type wet vacuum pumps 691 Piping scheme suggested for vacuum pan 693 Factors that influence heat transmission 713 Device for breaking whirlpool in jacketed hot well 714 Fort Wayne Sterilizer 720 Berlin Sterilizer 721 Sterilizer arrangement when using hot water in sterilizing 723 Relation between coming-up time, holding temperature, holding time and cooling time in sterilizing evaporated milk 724 Mojonnier Fvaporated Milk Controller 725 Average seasonal variations in the coagulation point of evaporated milk 753 Viscosity of evaporated milk 756 Fort Wayne Shaker 757 Berlin Shaker 758 Calcium citrate taken from cans of evaporated milk 762 General flow sheet of milk 849 Flow sheet of pasteurized whole milk 850 Flow sheet of pasteurized cream 850 Fig. 132 Fig. 133. Fig. 134. Fig. 135. Fig. 136. Fig. 137. Fig. 138. Fig. 139 Fig. 140 Fig. 141. Fig. 142 Fig. 143 Fig. 144 Fig. 145. Fig. 146. Fig. 147. Fig. 148. Fig. 149. Fig. 150. Fig. 151. Fig. 152. Fig. 153. Fig. 154. Fig. 155. Fig. 156. Fig. 157. Fig. 158. Fig. 159. I-Ig. Fig. 161. Fig. 162. Fig. 163. Fig. 164. Fig. 165. Fig. 166. Fig. 167. Fig. 168. Vig. 169. Fig. 170. Fig. 171. Fig. 172. FiR. 173. Fig. 174. Fig. 175. Fig. 176. Fig. 177. Fig. 178. Illustrations Fig. 179. Flow sheet of butter niannfacture at centralized creamery 850 Fig. 180. Flow sheet of bulk condensed milk manufacture 851 Fig. 181. Flow sheet of evaporated milk manufacture 851 Fig. 182. Flow- sheet of sweetened condensed milk manufacture.... 851 Fig. 183. Flow sheet of ice cream manufacture, Method 1 852 Fig. 184. Flow sheet of ice cream manufacture, Method 2 852 Fig. 185. Flow sheet of ice cream manufacture, Method 3 852 Fig. 186. Flow sheet of cheddar cheese manufacture 853 Fig. 187. Flow sheet of cream and skim-milk powder manufacture.. 853 Fig. 188. Flow sheet of whole milk powder manufacture 853 Fig. 189. Flow sheet of casein and milk sugar manufacture 854 Fig. 190. Flow sheet of milk chocolate manufacture 854 Fig. 191. Flow sheet of culture buttermilk manufacture 854 Fig. 192. Parts per million of metallic lactates required to impart a definite taste to water 857 Fig. 193. The influence of the acid content of milk upon the solubility of metals 859 Index of Tables Table 1. The water, fat and solids not fat content of dififerent dairy products derived from a certain whole milk 11 Table 2. Distribution of constituents of whole milk 15 Table 3. Solubility of milk sugar at different temperatures 25 Table 4. Fat percentages obtained by different methods 41 Table 5. Effect of using varyitig amounts of reagents 47 Table 6. Content of whole milk as found by three methods 51 Table 7. Comparison of fat tests by Mojonnier, Adams and Bab- cock methods 51 Table 8. Comparison of fat tost of skim-milk by Mojonnier and Bab- cock methods 52 Tabic 9. Comparison of fat test of sweetened condensed milk by Alojonnier method ; 52 Table 10. Comparison of fat test of buttermilk by Mojonnier and Babcock methods 53 Tal)Ie 11. Comparison of fat test of ice cream mix by Mojonnier and ' Babcock methods 54 Table 12. Composition of fat column in Babcock test bottles 56 Table 13. Total solids found by formula and by gravimetric method. 59 Table 14. Total solids test upon evaporated milk 60 Table IS. Total solids test upon sweetened condensed milk 60 Table 16. Dimensions and specifications covering the Mojonnier Milk Tester ." 68 Tabic 17. Influence of temperature upon the weight of aluminum dishes 77 Table 18. Influence of tem]K'rature upon weights of various objects. 77 Table 19. The distribution of water in. and loss of water by evapora- tion from, a cheddar cheese 89 Table 20. Laboratory report 105 Table 21. Summary of operations on the Mojonnier Milk Tester. .116-118 Table 22. Per cent S. N. V. and T. S. in cream 134 Table 23. Quantity of skim-milk to use in standardizing whole milk. 150 Table 24. Standardization of fat in cream 151 Table 25. Constants for evaporated milk 165 Table 26. Speciflc gravitv of evaporated milk testing 780% fat and 25.50% T. S. ." 172 Table 27. Specific gravitv of evaporated milk testing 8.00% fat and 26.15% T. S.' 172 Table 28. Relation of temperature to specific gravity in evaporated milk 173 Table 29. Relation between specific gravity and composition in evaporated milk 175 Table 30. Per cent of fat and S. N. F. in the proper ratio to stand- ardize evaporated milk 182 Table 31. Per cent of fat. S. N. F. and T. S. in evaporated milk after condensing 185 [ xxiii ] xxiv Index of Tables Table 32. Constants for sweetened condensed milk 221 Table 33. Specific gravity at various temperatures of sweetened con- densed milk 226 Table 34. Relation temperature to specific gravity in sweetened con- densed milk 226 Table 35. Relation temperature, composition and specific gravity in sweetened condensed milk 227 Table 36. Relation specific gravity, composition and temperature in sweetened condensed skim-milk 229 Table 37. Relation specific gravity, composition and temperature in sweetened condensed skim-milk 230 Table 38. Unit relation of temperature to specific gravity in sweet- ened condensed skim-milk 231 Table 39. Capacities and sizes of standard equipment for manufac- turing sweetened condensed milk, using Mojonnier process 234 Table 40. Composition of partly skimmed sweetened condensed milk. 239 Table 41. Composition of sweetened condensed milk 239 Table 42. Percentage of fat, S. N. F. in tbe proper ratio to standard- ize sweetened condensed milk 241 Table 43. Ratio between the pounds of total milk solids in the batch and pounds of sugar required, to make sweetened con- densed skim-milk 271 Table 43a. Suggested composition of ice cream mixes 273 Table 44. The physical and chemical properties and the nutritive ratio of ice cream mixes 277 Table 45. Commercial factors as influenced by composition of ice cream mi.x 280 Table 46. Influence of gelatin upon viscosit}' of water solutions 283 Table 47. Air whipped into various solutions of gelatin 284 Table 48. Name and description of flavors, fruits and nuts used in ice cream 287 Table 49. Influence of temperature and size of crystals upon the solubility of milk sugar crystals 291 Table 50. Influence of composition upon milk sugar crystallization.. 292 Table 51 Influence of miscellaneous factors, upon milk sugar crystal- lization 293 Table 52. Solubility of milk sugar in presence of other products 294 Table 53. Separation of milk sugar from ice 295 Table 54. Relative solubility of milk sugar at various temperature and in different media 296 Table 55. Influence of gelatin upon the physical properties of ice cream 299 Table 56. Number of bacteria per cubic centimeter in ice cream mix prepared in the vacuum pan 303 Table 57. Keeping qualities of ice cream mi.x prepared in the vacuum pan 303 Table 58. Approximate weight per gallon of water and of various dairy products 306 Table 59. Approximate composition of products used in ice cream mix 313 Table 60. A few combinations of cream and condensed milk 337 Table 61. A few combinations of dairy products 338 Table 62. Ice cream mixes made from sweetened condensed skim- milk and other products 355 InhKx of TAr.i.TCs XXV Table 6.3. Ice cream mixes usina; sweetened condensed skim-niilk and other products 335 Table 64. Ice cream mixes using sweetened condensed skim-milk and other products 356 Table 65. Composition of ice cream mixes for which standardizing tables are given 357 Table 66. Range of fat and S. N. F. in tables 358 Table 67. Standardizing table for ice cream mix testing 8.00% fat and 33.00% T. S 2>67-?>72 Table 68. Standardizing tal)lc for ice cream mi.x testing 8.00% fat and 34.00% T. S i7i-2,7^ Table 69. Standardizing table for ice cream mi.x testing 9.00% fat and 34.00% T. S 379-384 Table 70. Standardizing table for ice cream mix testing 10.00% fat and 35.00% T. S 385-390 Table 71. Standardizing tables for ice cream mix testing 12.00% fat and 35.00% T. S 391-396 Table 72. Standardizing tallies for ice cream mix testing 12.00% fat and 36.00% T. S 397-402 Table 7i. Standardizing tables for ice cream mix testing 16.00% fat and 38.00% T. S 403-408 Table 74. Standardizing tables for ice cream mix testing 18.00% fat and 40.00% T. S 409-414 Table 75. Ice cream mixes made from cream, evaporated milk, whole milk, sugar, gelatin and water 419 Table 76. Ice cream mixes made from cream, condensed whole milk. whole milk, butter and sugar 420 Table 77. Ice cream mixes made from condensed whole milk, whole milk, sugar, gelatin and butter 421 Table 78. Ice cream mi.xes made from cream, condensed skim-milk, whole milk, sugar and gelatin 422 Table 79. Ice cream mixes made from skim-milk powder, butter, sugar, gelatin and w-ater 423 Table 80. Ice cream mixes made from cream, butter, skim-milk powder, whole milk, sweetened condensed whole milk, sugar and gelatin , . . . 424 Table 81. Ice cream mixes made from cream, sweetened condensed skim-milk, butter, whole milk, sugar and gelatin 425 Table 82. Ice cream mixes made from skim-milk powder, whole milk, butter, sugar and gelatin 426 Table 83. Ice cream mixes made from sweetened condensed skim- milk, cream, sugar, gelatin and water 427 Table 84. Ice cream mixes made from sweetened condensed milk, butter, sugar, gelatin and water 428 Table 85. Ice cream mixes made from whole milk, butter, sugar and .gelatin to be condensed in the vacuum pan 429 Table 86. Ice cream mixes made from whole milk, butter, sugar and gelatin to be condensed in the vacuum pan 430 Table 87. Ice cream mixes made from skim-milk, butter, sugar and gelatin to be condensed in the vacuum pan 431 Table 88. Per cent M. S. N. F. in T. S. of cream of different tests. . . 438 Table 89. Composition of cocoa nibs, pure commercial cocoa and and cocoa shells 440 Indi'X of TablKs Table 90. Table 91. Table 92. Table 93. Table 94. Table 95. Table 96. Table 97. Table 98. Table 99. Table 100. Table 101. Table 102. Table 103. Table 104. Table 105. Table 106. Table 107. Table 108. Table 109. Table 110. Table 111. Table 112. Table 113. Table 114. Table 115. Table 116. Table 117. Table 118. Table 119. Table 120. Table 121. Table 122. Table 123. Table 124. Table 125. Table 126. Ta))lc 127, Table 128. Compo.'^ition of milk cliocolate 440 Composition of mi.sccllaneous food products 441 Correlation da?bcr speed, temperature incoming I)rine and mix and time required to freeze 459 Influence of quantity of culture added to media 527 Summary of experiment to determine influence of holding: temperature upon the growing^ qualities of cultures 531 Range of Baume Lactometers with products upon which they are to be used 563 Weight of sample recommended for lime determination.. 577 Lime content of dairy products 578 Volume of milk to be used frr sugar tk-termination 580 Table for the determination of lactose ( Soxhlct-Wcin ) . . 582 Munson and Walker table for calculation of sugars 587 A comparison of results by White's method for sugar determination 588 Percentage of citric acid recovered from milk products... 595 Titratable acidity of various dairj' products 604 Comparison of alcohol and acid tests 607 Fat constants 626 Rutyro-Refractometer readings and indices of refraction A 628 The separation of gums 635 1 dentilication of gums 636 Spccilic heat of skim-milk 653 Specific heat of whey 654 Specific heat of butter 655 Specific heat values for milk and milk derivatives 656 Detection of water added to milk by freezing point method 657 Ash and phosphorus content when coagulated at various intervals of time 664 Hydrogen ion concentration expressed in form of hydro- gen ion normal 667 Hydrogen ion concentration 672 Intermediate p^j and Cjj equivalents for use with Table 116 673 Relation of reaction colors to Pjj values 679 Values of p,^ of phosphate solution 681 Relation boiling points, vacuo and rate of evaporation... 685 Capacity per hour" of various sizes of vacuum pans 690 Sizes of vacuum pumps recommended for various sizes of vacuum pans 692 Pounds of water re(|uircd to condense one pound of water vapor 695 Percentage increase of water required, with incoming and outgoing condensing water at dififerent temperatures 697 Percentage increase in volume in excess of water required when the pan temperature is 140° F 698 Pounds of steam at various pressures condensed into whole milk 700 Pounds of steam required to forewarm and condense raw- materials 702 Relation of fuel consumption to steam production 704 Index of Tables xxvii Table 129. Available heat units, volume and temperature of steam at various temperatures 708 Table 130 Relation between temperature and time when coming up in sterilizers 722 Table 131. Relation of titratable acidity and heat coagulation 726 Table 132. Influence of acid content upon the coagulating temperature of milk 728 Table 133. Effect of period of lactation on the percentages of albumin. casein, and total protcid in milk 729 Tabic 134. Influence of added salts on the coagulating point of evap- orated milk 730 Table 135. Balance between calcium and citrates 733 Table 136. A sample in which calcium prevents coagulation 734 Table 137. Relation between concentration of evaporated milk and its acid content 734 Table 138. Efifect of rennet forming bacteria on curdling temperatures 726 Table 139. Determining steam distribution in the sterilizer 739 Table 140. Relation temperature, scale reading and coming up-time. 742 Table 141. Correcting viscosit}' of evaporated milk to 75° F 744 Table 142. Evaporated milk that failed to react to bicarbonate of soda 749 Table 143. Percentage of each protein constituent 754 Table 144. Viscosity changes in products used to make evaporated milk 755 Table 145. Influence of shaking on viscosity 758 Table 146. Changes in viscosity of evaporated milk under different storage temperatures 759 Table 147. Titratable acidity in evaporated milk! at various stages... 765 Table 148. Comparison of curdling efifect of coffee and water on evaporated milk 768 Table 149. Color and viscosity of evaporated milk under different methods of cooling 769 Table 150. Solubility of CO. in water 770 Table 151. State and territorial standards 824 Table 152. Grouping of cities and regulations available for study... 828 Table 153. Regulations relating to water 829 Table 154. Regulations relating to total solids 829 Table 155. Regulations relating to solids not fat 830 Table 156. Regulations relating to fat in milk 830 Table 157. Regulations relating to bacteria in milk 831 Table 158. Regulations relating to fat in cream 831 Table 159. Regulations relating to tuberculin test 831 Table 160. Regulations relating to bacteria in cream 832 Table 161. Regulations relating to temperature 832 Table 162. Regulations relating to specific gravitj^ 833 Table 163. Regulations relating to water supply 833 Table 164. Regulations relating to milkers 833 Table 165. Conditions which render milk legally unsalable 834 Table 166. Regulations in regard to parturition 836 Table 167. Regulations relating to milk house 837 Table 168. Regulations relating to milk utensils 838 Table 169. Regulations relating to city milk plants 839 Table 170. Regulations relating to dclivt*ry wagons 839 XXVlll IndKx Of Tables Table 171. Regulations relating to the milk 840 Table 172. Regulations relating to the scoring of dairy farms 840 Table 173. Temperatures for holding, manufacturing and storing dairy products 855 Table 174. Influence of temperature upon the solubility of metals in milk 858 Table 175. Comparison of metallic lactates required to impart taste, and of metal actually dissolved 861 Table 176. Conductivity or heat of certain metals, alloys and glass.. 863 Table 177. Degrees Twaddell with corresponding specific gravity. . . . 865 Table 178. Constants of the elements 866 Table 179. Specific gravit}' corresponding to degrees Baume for liquids lighter than water 870 Table 180. Specific gravity corresponding to degrees Baume for liquids heavier than v.'ater 872 Table 181. Properties of saturated steam 874 Table 182. Conversion of U. S. weights and measures. Customary to metric 876 Table 183. Conversion of U. S. weights and measures. Metric to customary 877 Table 184. Conversion of metric and British Imperial weights and measures, Metric to Imperial 878 Table 185. Conversion of metric and British Imperial weights and measures. Metric to Imperial 879 Table 186. Conversion of British Imperial and metric weights and measures, Imperial to Metric 880 Table 187. Miscellaneous equivalents of metric weights and measures 882 Table 188. Conversion of degrees Centigrade to degrees Fahrenheit, or vice versa 883 Table 189. Alcohol table for calculating the percentages of alcohol in mixtures of ethyl alcohol and water from their specific gravities 884 Table 190. Capacities of cylindrical tanks 887 Table 191. Composition of milk from dififerent mammals 888 LIST OF ABBREVIATIONS c. p. = Chemicall}^ pure c. c. or cc. = Cubic centimeter m. = Centimeter mg. = JMilligram gm. = Gram mm. z= ^Millimeter ^"^^m. — ■ Centimeter """^ b. p. =: Boiling point F. = Fahrenheit C. = Centigrade =: Inches — Feet Lbs. = Pounds 1^- S. = Total solids M. S. N. F. = ^lilk solids not fat S. N. F. = Solids not fat T. M. S. = Total milk solids T. S. N. F. = TotaJ solids not fat B. of H. = New York Board of Health Lactometer N. = Normal solution N/10 or 0. IN = Tenth-normal solution B. T. U. =: Biitish Thermal unit Sp. H. = Specific heat ° R. = Degrees retardation c. r= Small calorie C. =T. Large calorie Sq. cm. =T Square centimeter E. M. F. =r Electro motive force PH = Hydrogen ion concentration ^H = Hydrogen ion normal acid solution ^OH- = Hydrogen ion normal or normal alkaline solution A. O. A. C. = Association of Official Agricultural Chemists Sp. Gr. = Specific gravity IL = Baume R- = Bacillus ^, s u "o tt) CHAPTER I THE DAIRY PLANT LABORATORY The testing laboratory in a dairy plant does not generally receive the consideration that its importance warrants. This is so because it is of recent development, and the proprietors of many dairy plants do not yet fully realize the economical value of the -work. As they become more conscious of the fact that the composition of a marketable dairy product has a large influence on fixing its value and that the composition cannot be accurately determined without suitable accommodations and equipment, the laboratory and its work will receive as much consideration as other important operations in the manufacture of milk products. The loose methods in operation during the development of the industry will not prove successful under the present system of keen competition, and just as no business can hope to operate successfully for any length of time without an efficient system of accounting so a dairy manufacturing plant cannot hope to operate successfully without accurately determining the composition of each product received and distributed. The possibility of pre- venting loss through thorough control methods is of such im- portance that no reasonable detail should be overlooked in equipping the laboratory. Location. The laboratory should be a separate room located near the office and where practical, should have direct communi- cation with the manufacturing rooms. It should be used solely for analytical work and the chemist should not be annoyed or distracted by persons passing through it, nor by the conversation of others present. Where these precautions are observed valuable time may be saved, the work will proceed more rapidly, and the liability for mistakes to occur and consequent losses will be re- duced to a minimum. The air in most dairy manufacturing plants as a rule is exceedingly moist due to escaping steam, wet \ \ \ 2 The Dairy Plant Laboratory floors, and the large amount of water constantly us'ed for clean- ing purposes. Since excessive moisture is injurious to sensitive and delicate apparatus and makes accurate work more difficult, the laboratory should be located in the driest part of th-'j building. Moist walls, escaping steam and wet floors should be avoided as much as possible. Floor. A smooth floor that does not absorb moistui-e, and which may be easily and thoroughly cleaned serves best. Water from adjoining rooms should not be allowed to flow into the laboratory. Ample drains should be supplied to carry away wash water. Asphalt on a concrete base is very satisfactory, but any substantial floor will serve. The floor and walls should be solid and free from vibrations as they will have to support chemical balances, and other delicate apparatus that should rest on solid foundations in order to prevent their injury, and give the beist service. Ventilation. The ordinary means of ventilation, where pos- sible, should be supplemented by forced draft. This may be readily supplied and serve a double purpose by placing a flue leading from the hood. Proper ventilation will assist materially in freeing the laboratory of excessive moisture, noxious gases that should not be allowed to enter the manufacturing rooms, and in contributing to the health of the workers. Temperature. The temperature should be held at all times as near to 68" F. (20° C.) as is convenient. Wide changes in tem- perature are to be avoided because of the efl'ect upon the ap- paratus and upon the density of solutions. Tables and Desks. The laboratory tables should be substantial and covered with material impervious to moisture or chemicals. Where expenses must be kept down wooden tops stained black and treated with acid and alkali proofing substance are commonly used. Sheet lead laid over plank is favored by some and is pre- ferred to wooden tops. Glazed white tile or slabs of vitrolite give good service, and are very neat and attractive. Any finish that cannot be easily and thoroughly cleaned, or which is softened by heat should be avoided. While wooden drawers give good service, metal drawers made from pressed steel are an advantage because they do not swell nor check under varying atmospheric Equipment 3 or moisture conditions. Ample drawer space for storing ap- paratus should be provided under the benches and tables. The drawers should vary in depth from three to ten inches according to the apparatus they are to contain. The larger enclosed spaces under the benches should be reserved for the taller pieces of apparatus. Narrow shelves for holding reagent bottles should be placed on the walls over the work benches. Cupboards for hold- ing chemicals should also be supplied. Hood. No laboratory is complete or satisfactory without a roomy well ventilated hood. It should be equipped with sliding sash front to permit observation of operations Avithout opening the hood. Where available the hood as Avell as the work benches should be supplied with gas and water cocks. Sinks. The sinks should be large and conveniently located as much work must be done near them. Iron or porcelain sinks are to be preferred, and where they are to be used to carry away mineral acids, they should be lined with sheet lead, and the waste pipes should also be made of lead. Where possible the sinks should be supplied with hot as well as cold water. The plumbing should be so constructed that it may be readily reached when repairs are necessary. Steam and Electricity. Both steam and electricity can be used in many ways to advantage in the testing laboratory. Where power for operating a large amount of equipment is installed, it will be a comparatively simple detail to supply the laboratory. While it is not always indispensable, electricity is coming more into general use in laboratory methods, and in many analyses it is a real necessity. Lighting". Good light is a real necessity in laboratory work. A large skylight opening toward the north serves well, and where the location of the room permits, this means of lighting should be adopted. It should be supplemented with side lights where possible. The best light is obtained through north windows, but light from other directions will serve fairly well. The laboratory should also be provided with a good system of artificial light as it will be needed on dark days, and in the morning and late after- noon of the shorter days. White or light colored walls will also issist materially in giving good light. 4 The Dairy Plant Laboratory Apparatus. The larger and more important pieces of ap- paratus are the Mojonnier tester, balances, polariscope, micro- scope, viscosimeter, centrifuges, water-still, drying ovens, hot water bath, extraction apparatus, and muffle furnace. The Microscope. A good microscope is an essential piece of apparatus in every dairy plant laboratory. Where bacteriological work is carried on, it is an absolute necessity, and it will be frequently used in the examinations of milk sediment for dis- tinguishing yeasts and molds and detecting milk sugar crystals in condensed milk and other milk products, and for the study of butter fat globules. For these reasons the chemist should have a good microscope with all accessories immediately available. The following are the more important of the small, necessary items of equipment for a completely equipped dairy laboratory: Balance, Harvard trip, or torsion. Sensitive to 1/100 gram. Balance, specific gravity. Beakers, glass, 100 c.c, 250 c.c, 500 c.c. Beakers, aluminum, 150 c.c. Beaker covers (watch glass). Difl'erent sizes. Bottles, reagent. Glass stoppered, 250 c.c, 500 c.c, 1000 c.c. and 2000 c.c. Bottles, washing, with rubber stopper and flexible delivery tube. Bottles, weighing. Boxes, microscope slide. Brushes, wooden handles for cleaning cylinders and jars. Brushes, camel's hair for cleaning scale pans. Brushes, on tinned iron wire handle for cleaning long tubes. Burettes with glass stopcock. Capacity 10 c.c. and 50 c.c, graduated to 1/10 c.c. Burettes, Mohr's. For pinch cock. Capacity 50 c.c, graduated to 1/10 c.c. Burners, alcohol lamps, glass. Burners, Bunsen. Burners, Bunsen's ring form. Centrifuges, high speed, with accessories. Clamps, burette Lincoln. Clamps, Universal for condensers, etc Clamp holders. For attaching clamps, extensions, rings, etc. Clamp test tube. Clamps, tubing. Condensers, with bulb condensing tube, used in perpendicular position. Condenser, with straight condensing tube, used in slanting position. Connecting bulb tubes, Kjeldahl's. Corks, best quality, various sizes, Equipment Corks, rubber. Cork borers of polished brass, 12 in nest. Cork borer, sharpener. Cork softener, Cork screw. Cotton for plugging test tubes. Crucibles, glazed porcelain, with covers. Crucibles, Gooch. Gooch crucible holder, Bailey's. Crucible, platinum with cover, capacity 15 c.c. Crucible tongs. Cylinders, for use with hydrometers and lactometers. Cylinder, graduated 10 c.c, 25 c.c, 100 c.c, 1000 c.c. Desiccators, one large, one small. Dishes, crystallization, fiat bottoms. Dishes, evaporating, porcelain. Forceps, fine straight points. Drying oven, double walled for water. Extraction apparatus, heaters for. Files, round (rat tail). Files, triangular. Filter paper, various sizes. Filter paper, ash free. Filter cover, porcelain. Filter pump. Flasks, ordinary form. Flasks, Erlenmeyer, 125 c.c, 250 c.c, 500 c.c. Flasks, distilling. Flasks, for suction filtration. Flasks, Kjeldahl digestion. Flasks, sugar, accurately graduated at 100 c.c. and 110 c.c. Flasks, graduated at 250 c.c, 500 c.c. Funnels, glass, different sizes. Funnels, separatory. Funnel tubes. Furnace, muffle, for all kinds of muffle work. Glass rods. Glass tubing, various diameters. Hydrometers, specific gravity and Beaume scales. Lactometer, Quevenne. Milk sediment tester and accessories. Mortar, agate or porcelain with pestle. Pipettes, small with rubber bulb. Pipettes, volumetric, 5 c.c, 10 c.c, 25 c.c, 50 c.c. Ring stands, iron. Rings, support with clamp. Rubber policemen. 6 The Dairy Plant Laboratory Rubber ttibing. Sand bath, of iron. Shears, laboratory. Sieves, meSh, 20, 60, 80, ]00, 140, 180. Spatulas. Supports, burette, condenser and funnel. Test tubes, 10 c.c, 25 c.c, 50 c.c. Test tube racks. Test tube baskets. Thermometers. Tripods. Triangles, wire, and pipe stem. Tripods, iron for Bun sen burners. Tubes, connecting. Tubes, distilling. Watch glasses. \^'ater bath. ^Vire gauze. Wire gauze, iron with asbestos center. Additional Apparatus for Bacteriological Work. Autoclave. Sterilizers. Dry air sterilizing oven. Incubator. One c.c. pipettes, graduated in tenths. Test tubes, heavy walled. El-lenmeyer flasks, 1000 c.c. Petri dishes, 100 x 10 mm. Reading glass. Counting plate. Counter. ^Vax pencils. The following are the more impoitant chemicals required in a completely equipped dairy laboratory: Acid acetic, glacial 99.0%. Acid hydrochloric C. P. concentrated :J8.0%. Acid nitric C. P. concentrated 69.0%. Acid oxalic C. P. crystallized. Acid rosolic. Acid sulphuric C. P. concentrated 100%. Alcohol, amyl. Alcohol, ethyl, absolute Sp. Gr. .7938, and also 190° proof, 95%, Alum (potassium aluminum sulphate) crystallized. Ammonia, concentrated 28%. Ammonium chloride. .\mmonium molybdate, General PivANs Asbestos fibre. Barium chloride. Chlorinated lime, crystallized. Calcium peroxide. Carbon bisulphide. Cochineal, indicator. Copper sulphate, crystallized. Distilled water. Ether, moisture and residue free, both ethyl and petroleum. Ferric chloride. Formaldehyde, 40%. Fuchsin, crystallized. Glycerin, U. S. P. Potassium iodide. Lead acetate (crystallized). Litmus paper and cubes. Magnesium carbonate. Mercury. Methyl orange. Phenolphthalein. Potassium carbonate. Potassium hydrate sticks. Potassium permanganate. . Pumice stone. Eoehelle salts (crystallized sodium and potassium tartrate). Silver nitrate, C. P. crystallized. Sodium carbonate. Sodium hydrate, sticks. Starch. Tumeric, dry powder and paper. Xylol. ; Zinc dust. Tenth— normal sodium hydroxide. Tenth — normal hydrocliloric acid. Tenth — normal ammonium hydroxide. Tenth — normal silver nitrate. Saturated lime water. GENERAL PLANS FOR DAIRY LABORATORIES. No fixed plan can be recommended to suit all plants. Th conditions prevailing at each separate plant must be taken into consideration before deciding upon the arrangement and equip- ment of the laboratory. Fig. 1 shows the suggested floor plan for a plant laboratory where a number of different dairy products are manufactured. Under some conditions it might be desirable e The; Dairy Plant Laboratory Pig". 1. Sug-g-ested floor plan for laboratory in plant manufacturing- several different dairy products, including- evaporated milk, sweetened condensed milk and ice cream. 1. Mojonnier milk tester. 2. Evaporated milk controller. 3. Washstand. 4. Autoclave. 5. Sterilizer. 6. Incubator. 7. Hood. 8. Work bench. 9. Babcock tester. 10. Desk. 11. Chair. 18-0"- Fig-. 2. Sugg-ested floor plan for laboratory in plant manufacturing ice cream. 1. Mojonnier milk tester. 2. Washstand. 3. Autoclave. 4. Sterilizer. 5. Incubator. 6. Work bench. 7. Hood. 8. Desk. 9. Chair. General Plans 9 to divide the work into departments, and to partition the labora- tory into separate rooms. The arrangement of the control laboratory where such is maintained will be governed by the work to be done therein, and in many respects can be considerably different, both as regards arrangement and equipment, from the plant laboratory. Fig. 2 shows the suggested floor plan for a small factory laboratory where only ice cream or a limited num- ber of other dairy products are manufactured. The equipment in this case can be reduced to a minimum, being limited to ap- paratus for controlling fat and total solids and where so desired, for making bacteriological and a few other minor tests. CHAPTER II THE CONSTITUENTS OF MILK General Statement. Milk is the normal secretion of the mam- mary glands of mammalia during the period of lactation fol- lowing parturition. The definition of milk, adopted by the Association of American Dairy, Food and Drug Officials, Aug. 3, 1917, was the following: "Milk is the whole, fresh, clean, lacteal secretion obtained by the complete milking of one or more healthy cows, properly fed and kept, excluding that obtained within 15 days before and 5 days after calving, or such longer period as may be necessary to render the milk practically colostrum free." The milk of a number of different species of mammalia has been used as human food. In parts of the world the milk of the zebu, goat and sheep is of some commercial importance. Goat's milk in some instances has found favor in this country as food for infants of delicate digestion, probably because the casein does not readily mat into a lump when acted upon by acids in the stomach. The casein in that respect behaves more like the casein' in human milk. However, the substance commercially known as milk in this country, refers to the milk of the cow, and it is used in this sense in this volume unless otherwise specified. THE PHYSICAL PROPERTIES OF MILK. Milk and the products obtained from milk are so universally used that their principal physical properties are a matter of com- mon knowledge. Whole milk consists of an emulsion of light- yellow fat globules in an opaque white serum that usually has a slight bluish tinge. The color of whole milk as well as of other dairy products varies under many different conditions, both of production and manufacture. The practice of standardizing color is a long established one in man.y industries. Physical properties [10] Composition 11 Hi !«| « S O o a> ■s.s Skim- milk Powder o o o OS ol o id 1 in 00 Whole Milk Powder 8 o in o o o id 05 IN o «oro 3-3 »* « 8 00 T-l 8 CO O 00 CO 3. 2 j;""'fe M 9^2-00:5 rH «4-i ra CO O o 00 o o lO id IN 00 Plain Bulk Con- densed Whole Milk 8 d o o 00 o o IN (N 8 d CO CO 00 CO Plain Bulk Con- densed Slum- milk o •o IN IN id (N o if3 id IN i> CO Sweet- ened Con- densed Whole Milk com 3 o o 00 O o o in CO S *^ 0) ii d c O o TO 03 o o -*< d o d 05 cn 00 Cheese (Fresh American Cheddar) 8 00 CO o o d C<3 IN o o (N CO o 1:^ 1' 00 d O 00 d o o d O o 00 o o 00 Tfl s cs o CO o o d 00 TO id 00 CO lO Ol I1 00 o o IN 00 00 IN 00 OJ o 1- N.' 00 TO o lO 00 lO M IN o o o Constituents 1- i. « fe ■** o ca 12 1 ii 12 o 'a-i:^ 3 g 12 Constituents of Milk such as flavor, viscosity and appearance that frequently affect the sale of the product also vary under many different condi- tions. It is not within the province of this chapter to discuss these properties in detail. Further reference will be found in later chapters. THE COMPOSITION OF MILK. The constituents of milk and milk products divide themselves into groups both for commercial and scientific considerations. First: Water and total solids (ordinarily at least no attempt is made to account for the gases in milk). Second: The total solids are divided into two parts, one being called fat and the other solids not fat. Both of these later groups form the basis of our leading dairy industries. Third : The solids not fat are again further divided into their several component parts which will be described in later paragraphs. In Table 1 the composition is given of our most common American dairy products, in terms of water, fat, solids not fat, and total solids. It is assunied that the initial lot of whole milk weighed 1000 pounds, and that it tested 87.75 per cent of water ; 3.75 per cent of fat; 8.50 per cent of solids not fat, and 12.25 per cent of total solids. It is further assumed that the entire lot of products mentioned in the table were obtained from a similar quantity and composition of whole milk. The pounds of each kind of product thus obtained is given. Note the remarks in the case of sweetened condensed milk and in ice cream mix. The yield and composition of these products as mentioned could not have been obtained except by removing part of the fat in the case of the sweetened condensed milk, and by adding additional fat in the case of the ice cream mix. VARIATIONS IN CONTENT OF FAT AND SOLIDS NOT FAT IN WHOLE MILK. The composition of milk varies considerably, and the per- centage of no single constituent is constant between samples taken from different sources or different milkings of the same individual. The range of variation that occurred in the percentage of fat and in the percentage of solids not fat in the milk from 1217 herds is shown in Fig. 3. Composition 13 Tig, 3. Variation in fat and solids not fat in milk from 1217 Kew York Herds Tests made by H. C. Troy and W. B. White. 14 Constituents of Milk It also shows the general relation that exists between the per- centages of fat and solids not fat. The data represent the com- position of single samples of the mixed herd milk from 1217 different herds. They included the different breeds and classes of cows in central and western New York. The number of cows in the different herds is not known, but would probably average about ten. The samples were taken at all seasons of the year from the mixed herd milk by inspectors, experienced in such work, after watching the milking operation and making certain that the samples truly represented the milk produced by the herd at that milking. Several hundred of the samples were analyzed by one of the authors of this book, while he was State Chemist in New York, and the remainder were made by his successor, Mr. W. B. White, State Chemist, Ithaca, New York. The fat varied between 2.25 per cent in the lowest analysis to 6 per cent in the highest. The solids not fat varied between 7.25 per cent in the lowest analysis to 10.13 per cent in the highest. The percentage of solids not fat increases as the percentage of fat increases, but the ratio of increase is not constant and gradu- ally diminishes as the higher fat percentages are reached. The percentage of fat was obtained by the Adams extraction method excepting in a few cases where the Babcock method was used. The solids not fat were obtained by drying to constant weight 2.5 to 3.0 grams of milk in a flat bottomed platinum dish in a water-jacketed drying oven containing boiling water, and then subtracting the percentage of fat from the percentage of total solids. DISTRIBUTION OF CONSTITUENTS OF WHOLE MILK. Table 2, next page, was prepared to show at a glance the per- centage composition of each important class of constituents in whole milk, and likewise of the separate constituents making up the various classes. The various constituents are discussed both by groups and also individually in the following paragraphs. Gases. In the majority of dairy products, the material gases contained therein are of no practical or commercial significance. Gases are frequently the product of decomposition in which event they become undesirable constituents, and may cause large com- Composition 15 mercial losses, principally in the case of butter, cheese and sweetened condensed milk. In other prociiicts such as Koumiss, the development of carbon dioxide is of prime importance, and determines the commercial value of the product to a considerable extent. The principal gases found in fresj^ily drawn milk are carbon dioxide, oxygen and residual gases, \ generally assumed to be nitrogen, but this assumption remains uiVproved. The total volume amounts to about 7 to 9 per cent. According to Mar- shall's experiments, the above gases are present an the milk before the same leaves the udder. i TABLE 2. Distribution of Constituents of Whole Milk. \ ?^^ Glycerides of insoluble and non-volatile acids Olein 33.95 Palmatin 40.51 Stearin 2.95 > Myristin 1 0.44 Laurin 3.57 , Butyrin 6.33 ^ ^.i a c •' (jflvcerides of ^^P^°^" 2.32Loiu^j^ ^„d ^^P^y^"^ • -^M volatile acids Caprinm .34 j f Casein 3,60 ^ Albumin 60 Nitrogen Globulin traco \ containing Fibrin trace substances Lecithin 05 J [-3.40% ^ 0.30% 3.25% 3.70,% ] T. S. > 12.35% Milk sugar Citric acid . .4.50% .0.20% Ash .0.70% Solids ) not fat Potassium oxide .1751 8 65'/ Sodium oxide 070 Calcium oxide 140 Magnesium oxide .... .017 Iron oxide .001 Sulphur trioxide .027 Phosphorus pentoxide . . .170 Chlorine 100 Water 87,65'% Total 100.00% 16 Constituents of Milk Water. The water forms about 87% of the milk substance. It is derived directly from the blood and serves as a vehicle for carrying the other constituents of the milk in a fluid condition. The water may be separated from the other substances by dis- tillation. It may then be condensed and collected. After remov- ing traces of volatiJe gases, it has exactly the same composition and physical properties as pure water from any other source. Total Solids. The total solids include all of the milk con- stituents that are not evaporated when a small amount of the milk is spread over a large surface and dried to practically con- stant weight at a temperature of 100° C. The percentage of total solids may vary between 10.5 and 15.5. In a few exceptional cases it may fall outside of this range, but in the vast majority of analyses it will fall between 11.5% and 13%. The percentage of total solids in milk or other dairy products is of special im- portance as it is a measure of the food substance contained therein, and also because legal enactments have fixed minimum percentages of total solids for most dairy products. Solids Not Fat. The solids not fat are made up of casein, sugar, albumin, ash, and a few other less abundant, but neverthe- less important constituents. They form the solids in the serum after the fat has been removed. The white, opaque color of milk is largely due to their presence although the fat globules add to this property. In milk of average composition, the solids not fat supply about one-half of the energy producing substances and practically all the muscle building properties. The higher specific gravity of milk over that oi' water, is also due to these substances ; the specific gravity of the solids not fat being about 1.615. They increase the viscosity (sticky quality) of milk, and as some of them are not in complete solution, they assist in hold- ing the fat in an emulsified state, preventing its rapid rise to the surface, and complete separation from the remainder of the fluid under the influence of the force of gravity. Even when force is applied in centrifugal m.ethods of separation, the solids not fat prevent the removal of some of the smaller fat globules so that separator skim-milk rarely contains less than .05% of fat. Van Slyke and Bosworth^ state that sugar, citric acid, potas- sium, sodium and chlorine are wholly in solution, and that the Milk Fat 17 albumin, inorganic phosphates, calcium and magnesium are partly in solution and partly in suspension. Any of these substances that are in suspension would assist in holding fat in an emulsified condition. Skim-milk, buttermilk, whey, plain and sweetened condensed skim-milk and skim-milk powder owe their commercial im- portance to their content of milk solids not fat. The small amount of fat carried in these products also adds to their value. There is everywhere a growing recognition of the food value of milk solids not fat. Milk Fat. The fat from milk is generally known as it appears in butter. For this reason it is commonly called butter fat. Be- fore it is separated from milk it may be seen, with the aid of a microscope, in the form of minute opalescent globules floating in the milk serum. Different investigators have determined the diameter of the fat globules of milk. While their results are not wholly in accord, it appears that the diameters of the globules vary between 0.01 mm. and 0.0015 mm. (approximately 0.004 and 0.00006 inch). The fact that fat globules of milk do not readily unite, combined with other phenomena, led to the theory at one time supported by some investigators, that the globules are sur- rounded by a membrane, but there is scarcely evidence sufficient to support this conclusion. The consensus of opinion among in- vestigators is that the fat exists in the milk in the form of a true emulsion. The appearance of butter fat globules under the microscope varies with the product, and with the treatment which the product has received. "When fat is completely separated from the milk in the form of butter, it is characterized by its yellow color, and by desirable and attractive flavors and aroma. Animal fats may appear some- what yellow especially when melted to an oil, and by selecting the fats from certain parts of the carcases of cattle of some breeds, tallow may be obtained that has a yellow tint when solid, but the depth of yellow color in butter is not obtained in tallow, Fig-. 4. Fat Globules in Whole Milk. Mag'. 500 Sia. Courtesy Telling-Belle "Vernon Company Fig-, 5. Fat Globules in Ice Cream Before Homog-eniziug-. Mag-. 200 Dia. Courtesy Telling-Belle Vernon Company Fig-. 6. Fat g-lobules in Ice Cream Mix After Homogenizing. Mag. 200 Dia. Courtesy Telling-Belle Vernon Company Milk Fat 19 without the addition of foreign coloring. The yellow color of milk fat may vary according to the individual cow, the breed and the feed. The fat having the more pronounced yellow color is produced in the early summer, when the food is green and suc- culent, while the palest fat is produced in the winter months when such feed may not be obtained. The color of the fat in the form of butter is somewhat intensified by the addition of salt. Fig. 4 shows fat globules in whole milk. Fig. 5 shows the fat globules in ice cream mix before homogenizing, and Fig. 6 after homogenizing. The melting point of milk fat varies between 31° and 36^ C, (88° and 96° F.). A number of factors combine to influence the melting point, but the exact effect of each is not known. The specific gravity of milk fat ranges between .93 and .94 at 15° C. (59° F.). The fat expands as the temperature is increased, thus lowering the specific gravity until at a temperature of 60° (140° F.) it is about .90, and at 100° C. (212° F.) it is approxi- mately .864. Milk fat is composed of 9 different fats. Browne- made a study of the percentage of each present and obtained the following results. Palmatin 40.51%, olein 33.95%, myristin 10.44%, stearin 2.95%, laurin 2.73%, butyrin 6.23%,, caproin 2.32%, caprylin 53%, caprinin 34%. The fats are composed of three elements, carbon, hydrogen and oxygen. The atoms of these elements combine with each other under the force of chemical attraction to form molecules. The substances made up of these molecules possess different prop- erties according to the proportion of each element present, and the manner in which the atoms are combined. Combined in one way and one proportion, they form the well known substance called glycerine ; combined in another way and in differing proportion, they form a series of substances called fatty acids. In the elaboration of milk fat in the body of the animal nine distinct fatty acids are formed and combined with glycerine. Each molecule of glycerine holds three fatty acid radicles in com- bination. The acids present in milk fat are butyric, caproic, caprylic, lauric, myristic, palmitic, oleic and stearic. Combined 20 Constituents of Milk with glycerine they form the nine fats named above. It appears that any three of the fatty acids may unite with a glycerine radicle, thus forming a more complex molecule than would be possible if the glycerine molecule were combined with three radicles of a single fatty acid. The fat molecules may be split up into glycerine and fatty acids. By separating the glycerine and purifying it, the ordinary glycerine of commerce is obtained. When set free from the glycerine the butyric and caproic acids are soluble in water while the other fatty acids from milk fat are not soluble. The fatty acids of milk fat may also be grouped as volatile and non-volatile. When a mixture of fatty acids in water is boiled the butyric, caproic, eaprylic, capric and possibly some of the lauric acids are volatilized. By means of a distilling apparatus they may be col- lected and measured by titration with an alkali. This is one of the best methods of distinguishing milk fat from all other fats and oils as the percentage of volatile fatty acids in the latter is much lower. It is the presence of the fats from the volatile fatty acids, especially butyric, that gives butter its characteristic flavor. The fat in butter becomes rancid as a result of the splitting up of the fat molecule, as the fatty acids when freed from the glycerine radicle have very characteristic and pungent odors and flavors. The percentage of the harder fats is lowest during the earlier stages of the lactation period with a corresponding increase in the percentage of the softer fats. This has a practical bearing as the softer butter resulting retains moisture more readily than the harder butter made from fat secreted toward the end of the period of lactation. The manufacturing process must be modified to meet these difi'ering conditions or butter containing a percentage of moisture above the legal limit may result. Both from a physiological and commercial standpoint, the fat is the most important constituent of all dairy products. Thi? accounts for the exact control required over this constituent. Casein. Casein is the principal protein of milk, and it is present in the milk of all mammalia. It has been studied by a number of investigators, and different names have been given to the substance as it exists in fresh milk, and to the principal Casein 21 product derived from it iu the natural souring of milk. Van Slyke^ states that the neutral substance as it is believed to exist in fresh milk is calcium caseimate, consisting of casein iu combina- tion with 1.5% of calcium oxide. The true casein consists of the protein that remains after it has been separated from the calcium oxide. The name calcium paracasein is given to the insoluble substance formed by the action of rennet. The casein forms about 80% of the milk proteins, the albumin about 15%, and small amounts of other proteins make up about 5%. It appears that some of the same influences that affect the percentage of fat in milk, also may cause variations in the per- centage of casein. Casein is present in fresh sweet milk in the form of minute gelatinous particles satvirated with the remainder of the serum until the substance is evenly distributed throughout the mass of liquid. Substances that act in this manner are called colloids. The colloidal particles of casein do not pass through animal membrane or unglazed porcelain and may be separated from skim-milk by using these substances as filters. The calcium casein separated from skim-milk by this means, is a gelatinous substance nearly white in color. It is not quite as opaque as the casein pre- cipitated from milk by acids, and is not so readily ground to a white powder when dry. The casein molecule has a very complex structure being made up of a large number of atoms. The six elements that enter into its composition, and the percentage of each according to Kirchner* is carbon 53%,, hydrogen 7%, oxygen 22.70%, nitrogen 15.70%, phosphorous .85%, sulphur .75%. Pure casein may be separated from fat-free milk serum by precipitation with very dilute acid. Special precautions must be taken to prevent other milk constituents from contaminating the casein during the operation, and to wash it free from foreign substances before drying. In the natural souring of milk, the lactic acid which is de- veloped from the milk sugar, unites with the calcium of the calcium caseinate, forming calcium lactate, setting free the casein and precipitating it, in the form commonly seen in curdled milk. The precipitation of the casein begins when the acidity reaches 22 Constituents of Mii.k about .6% at 70° F. if the acid is developed normally in the milk. If the acid is added to the milk at a temperature of 70° F. a slightly lower percentage will coagulate the casein. The higher the temperature, the lower will be the percentage of acid neces- sary to cause coagulation. Casein is also coagulated by the salts of a number of metals and by concentrated alkaline solutions ; while dilute alkaline solutions and concentrated acid solutions dissolve it. Heat changes- the casein compounds in fresh milk under pressure and coagulates the casein at 130 to 140° C. The enzymes, rennin and pepsin also precipitate casein and are used extensively for this purpose in the manufacture of cheese. The specific gravity of casein is between 1.26 and 1.35. Casein serves primarily as a food as it is found in milk, and the usual milk products. It forms a large part of the substance of nearly all cheese, and gives to cottage cheese practically all of its food value. In some proprietary foods the casein is treated with sodium compounds, and other salts that are also found in milk, and other substances to make it more soluble or to give it special properties. Plasmon, Tila, Nutrose, Eucasein, Sanatogen, Lacto-Somatose and Argonin are trade names given to foods of this nature made from casein. Galalith and Lactoform are substances made from casein after precipitation with metallic salts, or by other means and then treated with formaldehyde. This substance may then be used for some purposes as a substitute for, or in imitation of bone, horn, ivory, celluloid, porcelain and similar materials. It is used in the manufacture of buttons, door knobs, knife handles, picture frames, tubes, rods, oil flasks, cartridge cases, sink plugs and corks. It is mixed with medicinal reagents to assist in administering them, and it is used in many massage creams, ointments and soaps. Glues, adhesives, putties, paints, calcimine, photographic mate- rials, glazing materials, dolls and toys are also sometimes made from it. It is also further used in calico printing, in making imi- tation leather, insulating material, washable oil paper, drawing and writing paper, and in treating cloth and felting, and loading silk and other cloth, to make them heavier. Milk Sugar. Milk sugar or lactose forms about 38 per cent of the total solids. The percentage present in milk from Milk Sugar 23 different sources, and from different milkings of the same animal does not vary over nearly as wide a range, as does the percentage of fat. It is composed of carbon, hydrogen and oxygen. Three modifications of milk sugar are known to exist, all of which be- have differently towards polarized light. First, the monohydrate or a milk sugar which has the formula Cj2 H„2 Oil -|- HoO. This is the ordinary crystallized milk sugar of commerce, and the form that crystallizes out from water 'solutions at room temperature. As the formula shows, it contains one molecule of water of crystallization. This water is retained upon heating to 100'' C. in the dry state, or in water in an un- saturated solution. At 130° to 140° C. the molecule of water is given off. At 170° C. it decomposes forming lacto-caramel. It melts at 203.5° C. with further decomposition. Its specific heat is 0.30 and its specific gravity is 1.54. Second, the anhydrous modification called [i anhydrous milk sugar Avhich has the formula Cj, Hjo On. Hudson" devised a method whereby this modification could be produced in a chemi- cally pure condition. His method is based upon the principle that this form crystallizes out of hot, supersaturated solutions of milk sugar. The specific gravity at 20° C. is 1.59. Third, another anhj^drous modification called a anhydride which is obtained when the monohydrate milk sugar is heated at 125° C. to constant weight. This form is very hygroscopic, and the evidence indicates that, upon dissolving in Avater, it goes back to the monohydrate form. The solubility of milk sugar has been studied by Dubrun- faut,"' C. S. Hudson," E. Soillard," Mack & Liedel,'' and in the laboratory of Mojcnnier Bros. Co. Milk sugar has both an in- itial and a final solubility. That is, by mixing an excess of milk sugar with water, a certain amount will go immediately into so- lution, and a further additional amount will also go into solu- tion, after prolonged mixing of milk sugar with water. It is this fact that accounts for the disagreement in results between different investigators. The final solubility at different tem- peratures is given upon the graph Fig. 7 and in Table 3, page 25. Constituents of Milk ^^ff^7)i3yf^y^sJJ'yoja a// ^ynj. Mii,K Sugar 25 TABLE 3. The Solubility of Milk Sugar at Different Temperatures. Temperature degrees F. Parts milk sugar dissolved in 100 parts water. 11.9 Temperature degrees F. Parts milk sugar dissolved in 100 parts water. 35 120 43.0 40 13.2 125 46.8 45 14.0 130 51.0 50 14.9 135 59.9 55 15.9 140 64.5 60 17:0 145 65.8 65 18.2 150 69.3 70 19.5 155 74.5 75 21.0 160 80.1 80 22.8 165 86.2 85 24.8 170 93.2 90 27.0 175 101.2 95 29.3 180 110.5 100 31.7 185 121.3 105 34.3 190 133.9 110 36.8 192 139.2 115 39.7 As indicated by the foregoing results, the solubility decreases with lowering temperatures, or vice versa. The rate of solution increases rapidly with rising temperatures. Between 32° and 35° F. the solubility increases at the rate of .17 parts of milk sugar to 100 parts of water for each degree F. of rise in tempera- ture. Between 190 and 192° F. the increase is at the rate of 2.65 parts, or 15.6 times greater than at the lower temperature. The crystalline monohydrate of milk sugar according to Traube^^ belongs to the monocliuic system, and the same has the following constants : a, b, c = 0.3677 ; 1 : 0.2143, B = 109° 47'. The faces are clinodomes. 26 Constituents of Mii,k A typical crystal is illustrated under Fig. 8. For purpose of comparison, typical crystals of cane sugar are illustrated under Fig. 9. This shows the characteristic difference between the two sugars. Fig. 10 is a photomicrograph of milk sugar crystals crystal- lized from a pure lactose solution by evaporation of the water at room temperature. Milk Sugar, like cane sugar, as pointed out by Browne,-"' crystallizes in a variety of forms. This is proved by examination of the above photomicrographs. This accounts for the lack of agreement upon the subject between aiithorities. Tig, 8. Typical Monoliuic Crystal of Milk Suffar tlie faces of wliicli are clinodomes. Pig-. 9. Typical Monolinic Crystals of Sucrose, I. Tatoular Form, II. Porm with Hemihedral Paces.-" Decomposition Products of Milk Sugar. Through the action of lactic acid bacteria, milk sugar is converted into lactic acid, one molecule of sugar yielding four molecules of lactic acid, ac- cording to the following equation : C, H,, Oi,+H,0 = 4 C3He03. In actual practice the theoretical amount of lactic acid is not realized, as a part of the sugar is broken down to form other substances, the principal of which are carbon dioxide and water. Only about 70% of the sugar that disappears is found in the form of lactic acid. A part of the acid, thus formed from the Milk Sugar 27 milk sugar, unites with the calcium, setting the casein free. The latter then coagulates and forms the curd of sour milk. When a little more than .20% of lactic acid has developed in milk its presence may be detected by its odor, and when the per- centage reaches .25% to .30% it is noticeable to the taste. "When .60%, of acid has developed in the milk the casein coagulates at ordinary temperatures, and when about .90% of acid has de- veloped the ordinary variety of lactic acid bacteria becomes in- active and the development of the acid_ ceases. Special forms of bacteria like those used in the manufacture of Yogurt (Bac- terium caucasium) develops acidity as high as 3%. Fig-. 10. Milk Sugrar Crystals. Magr. 200 Dla. Courtesy Telling-Belle Vernon Company. Milk sugar, when fermented by the action of certain special varieties of yeasts, also yields alcohol. With the presence of bacteria, lactic acid may be formed at the same time, and the casein is partly broken down. This form of fermentation is used in the manufacture of koumiss from mare's milk and kep- hir (or kefir) from the milk of cows, sheep or goats. Koumiss may develop as high as 3%' of alcohol and 1.25%, of lactic acid while kefir may contain a little more than 1% of alcohol and .9%; of lactic acid. Uses of Milk Sugar. Milk sugar is used to a large extent with cream and water in modifying cow's milk for feeding in- fants when it is desired to reduce the percentage of protein. Xt is supposed to have special value in checking undesirable fer- 28 Constituents of Milk mentation in the digestive tract. It is sometimes used as a food for consumptives, and in cases of dropsy and wasting diseases. It also finds use in pharmacy as a base for pills, tablets and other similar purposes. The percentage of milk sugar in concentrated milk products like evaporated milk and condensed milk varies according to the degree of concentration of the milk, and the percentage originally present. The condensing process does not necessarily cause any change in the milk sugar unless it is exposed to high temperature^ for a long time, thus partially carmelizing the milk sugar and giving it a darker color. This, in turn, gives a very light brown color to the milk. Where the concentration of milk is carried to a point that does not leave enough water to hold the sugar in solution, it crystallizes out, and the concentrated product has a sandy and gritty feeling on the tongue when tasted. If such product is used in the manufacture of ice cream without pasteurizing and diluting, it sometimes transmits this undesirable property to the frozen product. A large part of the milk sugar in sweetened condensed milk is usually present in the crystallized form. It is not considered objectionable in this substance, especially if the crystals are small enough to re- main in suspension. Milk sugar may readily become the starting point for many defects in dairy products. For this reason its properties and its behavior under varying conditions require close study. Albumin. Milk contains about .6 per cent of this protein. Because it is not present in milk in such large amounts, and is not of such commercial importance, it has not received as much study by investigators as has been given to casein. It differs from casein in composition, and in several of its properties. It is in solution in milk, and it may be coagulated by heat above 70° C. Acids do not coagulate it at ordinary temperatures and it is not coagulated by rennet nor by magnesium sulphate added almost to saturation. It contains no phosphorus, and about twice as much sulphur as casein. The albumin may be sepa- rated by boiling the liquid that remains after precipitating the casein from skim-milk with dilute acids or rennet, and filtering. The coagulated albumin will remain on the filter as a white Albumin 29 amorphous mass which is not as granular as casein that has been coagulated by acids. Sebelien" prepared pure albumin from milk and gives it the following composition: Carbon, 52.19%; hydrogen, 7.18%- nitrogen, 15.77%,; sulphur, 1.73%; oxygen, 23.13%. Albumin contributes about one^sixth of the protein food value of milk and whole milk products that retain all of the milk constituents. The albumin' in the whey obtained in the manufacture of cheddar cheese, is sometimes coagulated by heat and skimmed off. It is then made into an Italian form of cheese that is known as Ricotte. In the process of manufacturing milk sugar it is necessary to remove the albumin from the liquid. This is accomplished by heating the liquid to coagulate the albu- min, then passing it through filter presses. The albumin col- lects on the press cloths. When removed from these it is used as chicken feed, or in the manufacture of fertilizer. Mineral Constituents. Milk yields about .75% of ash when dried and burned in a manner to prevent loss of mineral matter. The ash does not accurately represent the salts in the milk as they are changed in the process of burning, and their exact com- bination is not definitely known. They are in solution with the exception of a little less than one-half of the phosphorus, and about two-thirds of the calcium which are in suspension accord- ing to Soldner.i" He estimates that the salts are composed of the following substances in the proportions given here: Per Cent Sodium chloride 10 62 Potassium chloride g 16 Monopotassium phosphate 12.77 Dipotassium phosphate 9,22 Potassium citrate 5 47 Dimagnesium phosphate 3 jl Magnesium citrate 4 O5 Dicalcium phosphate 7 42 Tricalcium phosphate g 90 Calcium citrate 23 55 Lime combined with casein 5. 13 100.00 v30 Constituents oi^ Milk In the ash the bases are united with phosphoric, hydrochloric, carbonic and sulphuric acids, and as oxides. It has been thought that the small amount of sulphuric acid present is derived from the sulphur contained in the protein. The mineral matter in milk varies between rather narrow limits. It appears to increase slightly as the percentage of sugar decreases and vice versa. The percentage of ash in naturally rich milk is usually higher than in poor milk. The percentage also increases in milk secreted toward the end of th^ period of lactation. There are very small amounts of other substances which would slightly affect the salts in solu- tion, but they are relatively not very important, as far as now known. Lecithin. This substance is found associated especially with milk fat, egg yolk fat and liver fat. It is also found to a limited extent in some other animal and plant cell material. It is some- times classed as a phosphorized fat and has the formula C44 H90 O9 NP, It is a yellowish white solid, soluble in ether and alcohol and may be separated from other food substances by the use of these solvents. When the extracted substance is treated with wa- ter, it appears to absorb it, but apparently does not go into com- plete solution, remaining in the form of an opalescent emulsion. When treated with an alkali it yields fatty acids, phosphoric acid, and other substances. Experiments by Supplee^^ and by Cusick^^ indicate that the fishy flavor frequently found in butter is due to the tri-methyl- amine derived from decomposition products of lecithin. Vitamines. In the past few years, investigators have proved that milk contains certain substances popularly called vitamines which are essential to health and growth. As yet none of these substances has been isolated, nor has their chemical identity been discovered. At the present time authorities are agreed that at least three distinct vitamines exist in milk. This number is known from their functional differences, ascertained largely by the bio- logical method. Largely at the suggestion of McCullom^^ and his associates, these have been named fat soluble A, water soluble B and water soluble C or anti-scorbutic vitamine, respectively. Fat Soluble A is especially abundant in milk fat, egg yolk fat, and in liver and kidney fat. It is also found in leafy vegetables. VlTAMINES 31 Water Soluble B is found in the non-fatty part of milk. It is also found in the yolk of eggs and in the leaves of plants. Fat Soluble A and Water Soluble B are found in greater abundance in milk and its products than in any other foods known up to this time. This is one of the strongest reasons why milk and its products should constitute a generous part of the diet of human beings from infancy to old age. It has been found by long and careful research that these two vitamines are not affected, re- duced, or destroyed by any of the usual manufacturing processes used in the home or in the factory in the handling of milk and its products. Pasteurized milk, evaporated milk, sweetened con- densed milk, ice cream, milk powder, butter and cheese all contain the above two vitamines in great abundance. Water Soluble C or anti-scorbutic vitamine is the least abun- dant in milk of the three vitamines named above. Even fresh milk just as it comes from the cow is deficient in this vitamine, and in any event its shortage should be supplied through other sources. Fortunately Water Soluble C is quite abundantly distributed in nature. Oranges and tomatoes contain it in relatively large quan- tities, providing a cheap and abundant supply. The addition to the diet of the juice from these products, either fresh or sterilized, can be practiced to advantage even in early infancy. Pig-. 11. Citrio Acid crystals prepared from cow's milk. Aliout one-half actual size. Prepared by one of ilxe authors.^ 32 ■ Constituents of Milk Citric Acid. This substance (H3 Cg H5 0^. HoO) or its salts is a normal constituent of milk. The amount in milk appears to vary but on the average about .20 per cent is probably present. It is a tri-basic acid and the crystallized calcium salt is sometimes found in evaporated milk. BartheP* states that by calculating the amount of alkali metals present in milk it is found that they are present in excess of the amount that would be satisfied by the chlorine and phosphoric acid and that investigations by Beau^^ lead to the conclusion that the amount of citric acid in milk is on an average .2 per cent. Crystals of citric acid prepared from cow's milk are illustrated in Fig. 11. Traces of a number of other substances such as adenine, guanine, silica, urea, iodine and lacto-giobulin are known to be present in milk. Babcock and Russell (1897)^^ found an enzyme called galactose that dissolves casein. It was prepared from cen- trifuge slime and its aqueous extracts possess proteolytic proper- ties to a considerable degree. It is most active in slightly alka- line solutions, and heat of 73° to 75° C. readily destroys it. The presence in milk of one or more proteolytic enzymes is now gen- erally accepted, although little is known of their composition. Fresh milk is sometimes amphoteric to litmus, that is, it changes red litmus paper slightly blue and blue litmus paper red. There- fore that indicator cannot be used in determining the acidity. This behavior of milk toward litmus is believed to be due to tho phosphates in milk, as some phosphate compounds in solution act in a similar way. Milk is acid to phenolphthalein, and this indi- cator is generally used in determining its acidity. The apparent acidity is largely due to salts of phosphorus which undergo a re- adjustment in the presence of an added alkali. The apparent acidity of fresh milk normally varies between .10 per cent and .18 per cent, but in exceptional instances he.s been found as high as .24 per cent, calculate'd as lactic acid. Rice^^ investigated the milk of individual cows ar.d found titratable acidities as high as .22%. High percentages of casein and solids not fat usually, but not alTv^ays, accompan.y high ap- parent acidity. Electrical conductivity and hydrogen concentra- tion did not differ from that of normal milk. Titration by the Van Slyke oxalate proc 5 12: ^1 aa.s < ■O (3 — M §5 < o Jelly after add- ing ethyl ether extraction Incomplete o < o 61 5 a o < o aj sa Oa Zo CO CO o> CO U5 CO CO CO CO o OJ J? CB ■n CO to 00 >o CO CO Ot >o CO a-. OJ o OJ in CO OJ 00 in 4 Is a o •A a o a o a a o o 1 a o lO o o IN in in IN to 0) a o o § to o 8 8 8 U5 CO IN in 8 in CO § < O « O 61) uS °2S 1^1 J < O a •2 Ml. iSaS o o V 01 U|CO^ Q l-§ a^^2 -S5f>■. a a! a « > •o d O 55 < o V 6t d a a > 1 CO n CO CO CO CO CO CO CO CO 05 CO CO CO CO (N CO CO CO CO eo CO T3 §s 0) o 4) 1 a o a 1 1 a 1 m 0) g 8 U5 lO 8 o m © 8 in IN a o a 1 s •o i to UJ s 8 o CO in o 8 in CO c Em (S a ">. a) > O £ a o a a u, a S o 3 O a ! a x: .J *^ a 3 O a Oj 3 a d o- a 3 o a OS a 3 o 01 •3 a 0] a 3 O a 03 § S3 a> o S a 3 o a 01 01 1 a 3 o a OS « a d i-l ♦J a s o a d a d i o a g a « « 3 a 1 a « a a 3 o a d d 3 t a d £; «j s a 3 O a d d a 3 O a d a 3 a a a a i a d 3 £ a d 5 £ o 1 o K s g 1 > s 01 a 3 S 6 1 03 .2 c o a a <: 1 3 ! a 60 u £ O 1 I > c 8 2: 1 d > > w u c 6 O 1 1 1 I-l 4. E 1 *-* a a O 48 Fat and Total Souds Tests « 5 So 5 0)25 ^dS a-|fe 33 o ai So > 5S U) 03 d 03 > 03 O Iz; h3 II 1 X o c illliP o iz; SI OS o SI > ■0 OS s ■? 1 1 1 t- M eo o ■* CO to in CO o cc cc to cc <: in H5 U5 lO lO X5 to in in cc M « cc M cc CC lO cc r-l cc cc 2 cc cc cc ■73 « u « 4, 5j o •^ O c a a a fl d O C3 u NH o :?; O o o o Iz; u; o in in 1 o iz; < O Iz; d 2 III S"l i d 03 > ■a 0] iz; to IN (O IM cc to in to to in t^ ^ll CO to 00 00 00 00 00 CC 00 00 00 00 00 00 00 „ „ 5j a s o 5, ^ "- s ■a*i a t=! a c la a w O CJ u ^ u j,D T3 O iz; o ^; II Si SI be 03 fl a > H OJ ^ ^ O! (^ o> o t- ei < fe«s o o o o o o to i-i o o < Pngh X 00 00 oc 00 00 00 >o 00 00 00 00 00 00 00 •d 0. fll T3<-. c fl o d ^ ^ ^ ^ 41 w 11 ^1 NW o 1 o ;z; o :z; O o m Iz; in in IN in g in in cc *** a o 2: s g iz; lO o S lO 4/ o IN in CO in o o cc 8 in (N S in cc ^ tf ill d 5=«£ IS si Si a|§ m 5i3S o££ Id 11 d 5^§ 11 111 a |«d ill «d ™a III d 0) U'l' d'H.o 2 " 2S £■§ feSS I'g fess 1^ si- >^n •S «i^ 3 III 3 > £ ai r m c < t sag si > 522 051 S lu i Comparative; Tests 49 A study of the results given in the preceding table proves the importance of using the various reagents in the right proportion, one to the other, and in the proportions that have been found by experience to give the correct results upon the various dairy prod- ucts. The quantity of both water and alcohol used have the largest influence upon the accuracy of the results. Using too lit- tle water causes a gelatinous precipitate when the ethyl ether is added, and in turn this causes low results. Using too much water raises the dividing line in the extraction flask, and makes it im- possible to pour off completelj^ the ether solution containing the fat, from the remainder of the reagents. Using too little alco- hol causes particularly a heavy jelly upon adding ethyl ether, and in turn causes results that are greatly in error. This emphasizes the importance of using only the best quality of ethyl alcohol, conforming to the specifications given. Using too much alcohol frequently causes too high results, due to raising the dividing line too much. Using too little of either ethyl or petroleum ethers causes too low results on account of the extraction of the fat be- ing incomplete, while using too much causes a waste of reagents without increasing the accuracy of the test. Variation in the quantity of ammonia used causes less disturbance than varia- tion in the quantity of the other reagents. RESULTS OF COMPARATIVE FAT TESTS RY MOJONNIER METHOD AND OTHER METHODS. Comparison of results by Mojonnier and Babcock methods upon whole milk. A careful experiment was made to determine the relative effi- ciency of the Babcock method as applied to fresh milk with the Mojonnier method. The tests using the Babcock method were made in two different Chicago laboratories. The tests using the Mojonnier method were made by F. M. Bundy. The results of the experiments are given in Fig. 13, next page. The horizontal line, which may be called the standard line, represents the values obtained using the Mojonnier method. The spots and stars represent the amount overread or underread by the Babcock method. 50 Fat and Total Solids Tests .30 18 .CO a .10 4 -0- - .10 • 4 30 8 jao 18 1 I .. p * LABORATORY N0.1 • LABORATORY NO 9 • UNOERPAIO Tig. 13. Results by Mojonnier and Babcock Methods Upon Whole Milk. Only the difference between the two methods is shown. All values above the standard line show overreading. All under the standard line show underreading. The stars give the values ob- tained by one laboratory, and the round spots those obtained by the second laboratory upon the same sample. The amounts that would have been overpaid or underpaid had the tests been obtained in a plant that buys its milk upon the butter fat basis are given both in per cents and in cents per 100 pounds, at the left of the table. Each one-tenth per cent is assumed to have a value of four cents. The differences, if any upon the same sam- ple as reported by the two respective laboratories, are repre- sented by the vertical bands connecting the stars and the round spots. The results of the experiments show plainly the wide varia- tion in tests obtained by the same operator, and also between two different operators. Out of a total of 52 samples tested, laboratory No. 1 reported 30 samples that tested more than .05% either over or under the standard line, and laboratory No. 2 upon the same number of tests, reported 27 samples that tested like- wise. Out of 104 tests, irrespective of the operator, 51.9% of the tests were overread and 43.3% were underread. A COMPARISON OF THE FAT PERCENTAGES ORTAINED IN SEVERAL MILK PRODUCTS BY DIFFERENT METHODS OF TESTING. Under the direction of one of the authors^" in the dairy test- ing laboratory at Cornell University determinations were made Comparative Tests 51 by various methods of the fat content of different dairy products. The results are given in the tables immediately following. TABLE 6. Fat Content of Whole Milk as Found by Three Methods; upon 14 Different Samples. Sample Number. Mojon- nier, Adams. Babcock. Sample Number. Mojon- nier, Adams. Babcock. 1 4.22 4.17 4.30 8 5.16 5.11 5.00 2 3.67 3.62 3.60 9 4.40 4.44 4.30 3 3.98 3.91 4.10 10 3.40 3.34 3.40 4 4.76 4.77 4.80 11 4.23 4.25 4.30 5 3.64 3.61 3.60 13 3.32 3.30 3.40 6 4.71 4.62 4.80 13 4.78 4.71 4.80 7 3.87 3.86 3.90 14 4.85 4.82 5.00 The results in the above table shov7 a close agreement between the Mojonnier and the Adams methods, when applied to fresh milk. There is a considerable disagreement in results between the Babcock and the other two methods. The difference is not constant in one direction, as in other comparative tests reported in this chapter. TABLE 7. Fat Content One Sample Cream Tested Seven Times by Two Methods, and One Sample Evaporated Milk Tested Eight Times by Three Methods. Cream, Evaporated Milk. Mojonnier method. Per cent. Babcock method. Per cent. Mojonnier method. Per cent. Adams method. Per cent. Babcock method. Per cent. 36.68 37.00 8.07 7.92 7.90 36.75 37.50 8.05 7.97 8.00 36.68 37.50 8.05 8.08 7.90 36.69 37.25 8.11 7.93 8.20 36.70 36.50 8.08 7.96 8.30 36.74 37.00 8.07 8.06 8.00 36.70 36.50 8.08 8.03 8.40 8.07 8.00 8.20 The above results show the close agreement by the Mojonnier method upon both products, and the considerable disagreement in results by other methods, both within themselves, and by comparison with the Mojonnier method. 52 Fat and Total Solids Tests TABLE 8. Fat Content of Skim-Milk as Found by the Mojonnier and the Babcock Methods. Tests Made by Prof. T. J. Mclnerney, Cornell Univ. Sample. Mojonnier method. Duplicate. Babcock test. Duplicate. Difference. Duplicate. 1 .10 — .10 .05 — .05 .05 — .05 3 .10 — .10 .06 — .06 .04 — .04 3 .11 — .11 .03 — .03 .08 — .08 4 .07 — .09 .05 — .05 .02 — .04 5 .29 — .30 .26 — .26 .03 — .04 6 .07 — .07 .01 — .02 .06 — .05 7 .074— .074 .04 — .04 .034— .034 8 .08 — .08 .03 — .04 .05 — .04 9 .24 — .27 .14 — .14 .10 — .13 Average .126 — .132 .074— .076 .051— .056 The above results prove that the Babcock method gives too low results when applied to skim-milk. The shortage in this experiment was found to range from .02 to .13%, or upon the average about .06%. COMPARISON OF RESULTS UPON SAME PRODUCT BY DIFFERENT OPERATORS, USING MOJONNIER METHOD. One sample of sweetened condensed milk was tested by six different operators using the Mojonnier method. The results obtained are given in the following table. TABLE 9. Fat Content Same Sample Sweetened Condensed Milk by Mojonnier Method, as Found by Six Different Operators, Compared with Results by Official Method.'" Operator No. Where tests were made. Per cent fat found. 1 2 3 Pecatonica, 111. Grayslake, 111 Burlington, Wis. 8.38 8.44 8.38 4 Burlington, Wis. 8.38 5 6 Valders, Wis Valders, Wis. Burlington, Wis 8.37 8.36 8.36" The above results indicate the close agreement possible to obtain between different operators, being one of the best possible proofs of the accuracy of the method. Comparative; Tests 53 TABLE 10. Fat Content of Buttermilk by the Mojonnier and Babcock Methods Mojonnier Method. Babcock Method, | Regular Procedure. 17.6 cc. buttermilk. 17.6 cc. acid, 16" disk. Centrifuged atlOOOR.P.M. for 5, 2 and 1 mins. Babcock Method, Modified Procedure. 17.6 cc. buttermilk. 23.0 cc. acid, 16" disk. Centrifuged atlSOGR.P.M. for 10, 2 and 1 mins. Pei- cent fat. Per cent fat. Per cent fat. Original. Duplicate. Original. Duplicate. Original. .44 Duplicate. 1 .528 .523 .46 3 .693 .710 .12 .12 .41 .46 3 .661 .667 .16 .14 .37 .31 4 .333 .332 .04 .04 .06 .07 5 .356 .350 .05 .04 .09 .07 6 .299 .295 .18 .18 7 .328 .320 .05 .05 .21 .22 8 .325 .323 .03 .03 .09 .13 9 .431 .390 .08 .08 .20 .20 10 .480 .440 .17 .17 .27 .27 11 .597 .586 .26 .25 .34 .37 12 .431 .449 .07 .07 .30 .30 13 .432 .434 .12 .12 .20 .20 14 .472 .475 .11 .11 .25 .25 15 .447 .451 .10 .10 .25 .25 16 .386 .382 .05 .06 .18 .20 17 .649 .646 .27 .27 The above results indicate that the present method of apply- ing the Babcock test to the determination of fat in buttermilk is useless, as it is misleading, and it may lead to considerable loss. COMPARISON OF RESULTS BY MOJONNIER AND BABCOCK METHODS UPON ICE CREAM MIX. A number of compartive tests upon the different qualities of ice cream mix are given in the following table.-- 54 F'at and Total Souds Tests TABLE 11. Compaiison of Results by Mojonnier and Babcock Methods Upon Ice Cream Mix. Wholesale grade. All ingredients in mix. Ready for freezing. Philadelphia grade. All ingredients in mix. Ready for freezing. Per cent fat. Per cent fat. Over Under- Over- Under- Sam- ple Mojon- nier Bab- cock read- ing read- ing Sam- ple No. Mojon- nier read- Bab- ing read- ing No. By Babcock method. By Babcock method. 1 9.85 8.50 1.35 22 14.39 14.00 . . .39 2 10.62 8.60 2.02 23 14.89 15.00 .11 3 10.09 8.40 1.69 24 16.70 15.50 . . 1.25 4 9.61 8.35 1.26 25 14.64 14.40 .24 . 5 9.65 8.40 1.25 26 15.15 15.40 .25 6 10.36 9.20 1.16 27 14.77 14.80 .03 7 9.55 8.40 1.15 28 15.81 15.40 . . .41 8 10.00 10.18 9.72 9.61 9.60 9.60 9.60 9.00 .40 .58 .12 .61 29 15.33 15.00 . . .33 9 10 Speci al mi.x. No cane sugar added. 11 30 11.09 8.00 . 3.09 12 9.83 9.60 .23 31 11.80 10.00 . 1.80 13 10.12 9.20 .92 32 12.58 9.80 . 2.78 14 10.35 8.80 1.55 33 11.92 9.60 . 2.32 15 10.03 9.00 1.03 34 11.82 9.20 2.62 16 10.02 8.80 1.22 35 11.60 8.50 . 3.10 17 10.43 9.60 .83 36 11.20 8.65 2.55 18 10.36 9.20 1.16 37 12.04 9.10 . 2.94 19 10.72 10.40 .32 38 11.78 9.30 . 2.48 20 9.44 9.60 .16 . . . 21 10.09 9.80 .29 In the above mixes the milk S, N. F. was as follows : Philadelphia grade 6.50% milk S. N. F. Wholesale grade 10.00% milk S. N. F. Special mix 18.00% milk S. N. F. Inasmuch as the mix containing the lowest amount of milk S. N. F. shows the closest agreement, and that containing the most, the greatest disagreement in results by the two methods, Accuracy of Tests 55 W. 0. Frohring," concludes that this factor largely controls the difference. Other factors causing errors by the Babcock method enter into the testing of ice cream mix, as well as in the case of other dairy products. The results given in the table indicate the possibilities for serious errors when the Babcock method is used to test ice cream mix. The results reported by the Babcock method included only those in which the fat column was entirely clear. Nine grams of the ice cream mix were placed in eight per cent milk bottles. To this was added 9 c. c. of acetic acid, and the usual amount of sulphuric acid. All readings were made from a water bath at 140° F. PROOFS OF ACCURACY OF FAT DETERMINATIONS MADE BY THE MOJONNIER METHOD. In a careful experiment-^ the fat obtained from a large num- ber of milk fat extractions on the Mojonnier Tester was itself tested for purity by the Mojonnier method. The fat was weighed into the extraction flask, 10 c. c. of water added and the deter- mination completed in the usual way. The results were as follows : Weight of fat in the sample taken 4004 Weight of fat recovered 4003 Per cent of fat in the fat extracted from milk products 99.98 Per cent of moisture in the fat extracted from milk products 0.02 These results prove that the substance extracted from milk products by the Mojonnier method is practicall}^ chemically pure milk fat. In another experiment an accurately weighed amount of pure fat was placed in an extraction flask and extracted according to the procedure described above. With two extractions 99.90 per cent of the fat was recovered. With three extractions 99.97 per cent was recovered. When pure fat was added to skim-milk, in which the fat had been previously determined for the purpose of making the necessary corrections, the total recovery of the pure fat amounted to 99.96 per cent with two extractions. 56 Fat and Total Solids Tests These results show that pure fat under the conditions given can be practically completely recovered when the determina- tion is made by the Mojonnier method. For the purpose of comparison, in another experiment, two large samples of the product recovered from the fat column in Babcock test bottles were tested for fat, moisture, and total solids with the results given in Table 12. TABLE 12. Composition of Fat Column in Babcock Test Bottles Sample. Per cent of moisture. Per cent of Solids not fat. Per cent of fat. No. 1'* No. 2^= 3.01 .85 6.29 3.99 90.70 95.16 These results show that the fat column in the Babcock test is not composed of pure fat. The amount of substances not fat present are probably offset to some extent by the fat not col- lected in the fat column, but no doubt variations in the amount of these substances in the fat column are responsible for some of the inaccuracies of the test. (B) TOTAL SOLIDS AND MOISTURE TESTS. The total solids test of many dairy products ranks closely in importance with the fat test. Among the principal reasons being that the percentage of total solids in pure milk varies between quite wide limits ; the minimum percentages for total solids have been fixed in many cases by legislative enactments, and by muni- cipal and state regulations, and in the manufacture of concen- trated milk products. The percentage of total solids affects both the process and the quality of the product and the cost thereof. As in the case of butter fat, a large amount of work has been done in the past in devising satisfactory methods for estimating total solids in milk and its products. The efforts have been directed principally in two directions, namely (1) by formulas based upon the butter fat test and the specific gravity, and (2) by various modifications of gravimetric methods, Babcock,^^ Richmond" and Fleischman,^^ all published formulas for calculating total solids in dairy products. These formulas SOUDS FoRMUIvAS 57 are all based upon knowing the specific gravity of the milk, and the percentage of fat present, so that these determinations have to be made before the percentage of total solids can be calculated. If the method is used in practical work, the Quevenne lac- tometer reading is taken, and this reading is used in the formula. The fat is determined by the Babcock or similar method. "Work- ing in this way the calculations can be depended upon to give only a rough approximation of the true percentage of total solids present, particularly in the case of condensed milk products. The Babcock formula is favored in this country over other formulas. It is as follows: Total solids =-^-f 1.2 xF L = Quevenne lactometer reading F = Per cent of fat Problem : The Quevenne lactometer reading of a milk sample is 31 and the per cent of fat is 3.60. Q1 Total solids =:^ + 1.2 x 3.6 = 12.07 4 ' Another formula that gives results as dependable as the above especially when used on rich milk is the following : Solids not fat == ^ — ■ 4 Problem : The Quevenne lactometer reading of a milk sample is 32 and the per cent of fat is 3.80. 32-t- 3 80 * Solids not fat — — = 8.95%, 8.95%, + 3.80 = 12.75, % of total solids This subject is discussed at length by numerous authorities to which the reader is referred for further information. In the gravimetric methods the underlying principle in all cases is the same, but they differ from one another in many par- ticulars. In all cases a weighed quantity of milk is dried to constant weight at about the temperature of boiling water, either with or without the use of any absorbent materials. Among the best known of the gravimetric methods are the Babcock asbestos method, the method of the Society of Public Analysts of England, the Adams paper coil method and Mojonnier method. SS F'at and Totai, Solids I'^esTS Bigelow and Fitzgerald-" in their able research made a thorough investigation of methods for determining total solids in evaporated milk. They found "that the addition of sand to milk in drying constitutes a danger rather than a safeguard, and needlessly complicates the method." The gravimetric method recommended by them for deter- mining total solids in evaporated milk was as follows : "Weigh two grams of sample into a three-inch lead bottle cap ; add about 5 c. c. of water to dissolve the milk and distribute it over the bottom of the dish; heat in the water jacketed oven under atmospheric pressure until the sample is evaporated to apparent dryness. Continue heating for four hours and weigh. Eeturn to the oven and heat again for two hours and weigh. If the two weights show a loss of more than 0.05 per cent, the heating is continued, with weighings at two hour intervals until the last two weighings do not differ by more than 0.05 per cent." They made a comparative study of results obtained by the above gravimetric method, and by formula based upon the but- ter fat test and the specific gravity of the sample. The formula recommended by them to be used with both raw and evaporated milk was as follows : Per cent total solids = 1.2 x fat + (specific gravity — 1.000) 0.25. They found "that with sterilized evaporated milk more ac- curate results were obtained on the original samples than after dilution. Before sterilization the product is of course, more fluid and the specific gravity can be determined more readily, and the results are somewhat more accurate than in the processed milk. Even in that case, however, the method of calculation from the specific gravity is not as accurate as the determination by drying, and the latter is strongly recommended." The results reported are given in Table 13. J. J. Mojonnier introduced the method now known as the Mojonnier method in 1915. The principles underlying this method are covered by process patents dated April 3, 1917. It differs in several particulars from all other methods previously employed. MojoNNiER Solids Test TABLE 13. 59 Total Solids Found by Formula and by Gravimetric Method. Bigelow and Fitzgerald. Per cent total solids. Sample No. Calculated from specific gravity. Specific gravity bottle, undiluted. Specific gravity bottle, rliluted 1—1. "Westphal balance, diluted 1—1. Specific gravity spindle, undiluted. By drying. 802 807 824 834 836 837 840 26.64 26.46 26.87 26.76 24.77 26.88 28.70 26.29 26.28 26.27 24.49 26.60 28.32 26.44 26.28 26.84 26.47 24.89 26.84 28.68 26.83 26.83 26.56 24.71 27.29 28.89 26.68 26.54 26.81 26.50 25.05 27.13 28.59 The patented apparatus designed to carry out the method is all embodied in the Mojonnier Tester, already described. The two main advantages of the Mojonnier method are the great sav- ing in time possible to effect, and the increased accuracy of the re- sults obtained. The saving in time over the official method is illustrated by Fig. 14. Total Solids Test Mojonnier Test — 25 minutes. Long- Drying Test — 7 hours. Seventeen times as long. Fig*. 14. Saving- in Time ITpon Total Solids Test. PROOF OF ACCURACY OF THE MOJONNIER TOTAL SOLIDS TEST. A series of ten total solids determinations upon the same sam- ple of evaporated milk were made by J. J. Mojonnier upon April 7, 1915, with the following results: 25.95, 25.91, 25.95, 25.97, 25.93, 25.91, 25.97, 25.92, 25.93 and 25.99. These results show marked agreement in the entire series. Through the courtesy of the National Dairy Co., Toledo, Ohio, we report the results given in Table 14, being the tests obtained 60 Fat and Total Souds Tests upon samples of milk from the same batches by their operators of the Mojonnier Tester, and by the operator in the central laboratory at Chicago, also using the Mojonnier Tester. TABLE 14. Total Solids Test Upon Evaporated Milk by Two Operators. Where tests were made. Sample No. 25 Sample No. 36 Sample No. 59 Sample No. 82 N'ational Dairy Co., Morenci, Mich. . . . Mojonnier Bros. Co., Chicago, 111.; Miss Lucy Klein 26.66 26.57 26.19 26.24 26.30 26.29 26.41 26.40 The ability of different operators to obtain practically dupli- cate results upon the same samples of evaporated milk is one of the best proofs of the accuracy of the method. We are also indebted to the Wisconsin Condensed Milk Co. for comparative tests upon sweetened condensed milk samples all from the same batch, tested by different operators using the Mojonnier Tester, in comparison with test by the official method. The results are reported in Table 15. TABLE 15. Total Solids Tests Upon Sweetened Condensed Milk by Several Operators. Operator No. Where tests were made. Per cent total solids found sweetened con- densed milk. 1 Pecatonica, 111 73.27 2 Grayslake, 111 73.41 3 Burlington, Wis 73.41 4 Burlington, Wis 73.50 5 Valders, Wis 73.50 6 Valders, Wis 73.31 Mr. Titus' official test. Burlington, Wis 73.53 Considering that sweetened condensed milk is probably the most difficult dairy product to test successfully for total solids, the results reported show a close agreement with those obtained by the long official methods, Rei^ErEnces 61 references. 1 Rose, Bruno: Analysis of Milk: Fat Determinations. Zeitschrift fur Angewandte Chemie. Abst. in Jour. Chem. Soci., Vol. 54, p. 1135, 1888. ^ Schreib, H.: Determination of Fat in Milk. Zeit. Angewandte Chem., Vol. 1, p. 135, 1888. Abst. in Jour. Chem. Soci., Vol. 54, p. 1135, 1888. 'Gottlieb. E.: Estimation of Fat in Milk. Milkerei Zeitung, 1892, II. Landw. Versuchs.-Stat., Vol. 40, p. 1-27. Abstract in Jour. Chem. Soci., Vol. 62, p. 549-550, 1893. Patrick, U. S. Dept. Agric, Bur. of Chem., Circ. 66; A. O. A. C. Methods, * Lang: Pharm-Zeitg., 38, 219. Chem. Centr., 1. 960, 1893. sWeibull: Milk Ztg.. Vol. 27, p. 406, 1898. Cheni. Ztg., No. 63, 1898. «Kuhn: Milk Ztg., Vol. 27, p. 772, 1898. ■^ Popp, M.: Zeitschrift fur Untersuchung der Nahrungs- und Genussmit.. Vol. 7, p. 772, 1. s Popp, M.: Milch.-Ztg., 1904, No. 20. » Rohrig: Amir. Zeit. Nahr. Genussm., A^ol. 9, p. 531-538, 1905. I'Thomsen: Th. Sv. Landw. Versuchsstat., Vol. 62, p. 387-399, 1905. "Burr, A.: Milchw. Zentr., 1, 248-250. Abstract Jour. Chem. Soc, 88. 2, 559-560, 1905. '2 Gordon. P.: Milchw. Zentr., 2, 224-227, 1906. Jour. Chem. Soci., 90, 2, 501, 502, 1906. '*Barthel. Dr. Chr.: "Milk and Dairy Products." Translated by Goodwin, "W., Ph. D., MacMillan & Co., N. Y. p. 52-55, 1910. ^* Kropat, K. : Arch, der Pharmacie, Vol. 252, p. 76-82, 1914. Jour. Soci., 106, 2, p. 591, 1914. 's Richmond. H. D.: Dairy Chemistry. Second Ed. Revised, p. 118-119, 1914. i« Meniere, G. J.: Pharm. et Chim. (7) 9, p. 489-493, 559-563, 1914. Jour. Chem. Soc, 106, 2, p. 590, 1914. '^Balton, E. R., and Revis, C: Fatty Foods, Their Practical Examination. London, 19, p. 347-349. '*Bigelow, W. D., and Fitzgerald: The Examination of Evaporated Milk. Bull. No. 5, Jan., 1915. Research Lab. Nat. Canners Assn., Washington, D. C i» Biesterfeld & Evenson: Jour. Ind. & Eng. Chem., 1917. *'» Courtesy Wisconsin Condensed Milk Co. 21 Test made by Mr. Titu,s, Burlington, Wis., using official Rose-Gottlieb Method. 22 Courtesy Telling-Belle Vernon Co., Cleveland, Ohio. Results reported by W. O. Frohring, Director of liaboratories. 23 Miss Lucy Klein: Mojonnier Bros. Co., Chicago, 111. 2* Sample from Dairy Testing Laboratory. N. T. State College of Agricul- ture. Analyst, Miss l./ucy Klein, Chicago, 111. -s Analyst, F. M. Bundy, Chicago, 111. 2«Babcock: Univ. of Wis. Agr. Exp. Sta., 1895, 12th, Rep't., p. 120. 2'' Richmond: "Dairy Chemistry," 1914, p. 68. 28 Fleischmann: Lehrbuch der Milchwirtschaft. 2» Bigelow & Fitzgerald: The Examination of Evaporated Milk, 1915. Bull, No. 5. Research Lab., Nat. Canners Assn., Washington, D. C. »o H. C. Troy. CHAPTER IV ASSEMBLING THE MOJONNIER MILK TESTER The Mojonnier Milk Tester is a machine invented especially for the purpose of quickly determining, with the greatest chem- ical accuracy, the percentages of fat and solids in all dairy products. The Mojonnier Milk Tester is supplied in three models. Model A is electrically operated with rheostatic heat control throughout. Model D is electrically operated, with rheostatic heat control upon the two outside hot plates, and with thermostatic heat control upon the two ovens. This insures uniform temperature upon both ovens, regardless of any fluctuations in the voltage. Model G is steam operated. The three models are illustrated under Figures 15, 16 and 17, respectively. Viir. 15. Model A Mojonnier Milk Tester. ElectricaUy operated. Rheostatic heat control. [ 62 ] MoDKlvS 63 Figr. 16 Model D Mojonnier Milk Tester. Electrically operated. Thermo- static heat control upon the two ovens. Tig. 17. Model G Mojonnier Milk Tester. Steam operated throughout. 64 ASSEMBUNG MOJONNIER MlI,K TesTER SETTING UP THE MOJONNIER MILK TESTER. In assembling and locating the Mojonnier Milk Tester in the plant, follow instructions closely. The illustration Fig. 18 will assist in properly setting up the Tester. The tester must be placed in a room with a good solid floor, in order to prevent vibra- tion of the chemical balance. Choose a corner space preferably, or a straight wall. The air in the room should be fairly dry and the temperature between day and night should not vary widely. 30 31 25 II 7 10 3 13 6 4 1 r 16 29 14 15 19 18 24' The Mojonnier Milk Tester. Model A. (1.) All tests for fat are made upon this side, which is called the fat side. (2.) All tests for total solids are made upon this side, which is called the solids side. (3.) Butter fat extraction flasks in centrifuge baskets. (4.) Eight 3|" diameter aluminum dishes for fat tests. These are the larger " dishes furnished with the Tester. The one tall counterpoise counterbalances each dish. Fat dishes have no covers. Parts 65 (5.) Eight 3" aluminum dishes for solids tests. These are the smaller dishes furnished with the Tester. The one short counterpoise counterbalances each dish. Cover prevents absorp- tion of moisture from the air during weighing. Counterpoise balances both dish and cover. (6.) Fat vacuum oven. The temperature in this oven is main- tained at 135 deg. C. Thermometer (10) extends into vacuum oven and sets in the mercury well, which in turn rests upon the hot plate. About once a month the mercury well should, be re- filled with mercury. Be careful to see that the well always forms good contact with hot plate. Regulate temperature by rheo- stat (15). (7.) Cooling chamber. Water at room temperature from the tank in bottom part of the fat side is pumped by means of cir- culating pump in power unit (20) through the flat hollow sheet brass plate inside the cooling chambers, and from there into pipe back of the Tester, then back into tank. Operator must watch outlet on cooling chamber, and see that water is flowing at all times while the motor is running. If water is not running, you may know that the water in the storage tank- is low, or that the water circulating pump is out of repair. Keep the tank filled at all times. In winter to prevent freezing, put one gallon of de- natured alcohol into the tank. Also when filling tank, put in one- half gallon soluble oil furnished with the Tester, This will assist greatly in keeping the circulating pump in repair. (8.) Solids oven. Maintained at 100*^ C. Regulate tem- perature by means of the rheostat (16). Follow instructions in (6) above closely for method of placing thermometer. Keep joints at door clean, and grease the sliding surfaces with vaseline. This prevents rusting of the ground surfaces, and insures a more per- fect vacuum, (9 and 10.) These are the 250° C. thermometers furnished for the solids and fat ovens respectively. Two sizes of gum tubing are furnished, for fastening the thermometers to the ovens. No other quality of tubing should be used, and if necessary, the tub- ing should be wired to the thermometer and to the oven connec- tion. (^ Assembling Mojonnier Milk Tester (11.) The vacuum gauge is on the main suction line from the vacuum pump. This registers the vacuum upon either oven, or upon both ovens simultaneously. (12.) Outside solids plate. Maintained at 180° C. The ther- mometer can be placed in the nickel plated mercury well that rests directly upon the heating plate. See that this side is level, so that the solids may dry evenly upon the bottom of the dish. (13.) Outside fat plate. Maintained at 135° C. During the evaporation of ether from the dishes, the temperature falls. The temperature may be kept at 150° C. at the start, and the dishes placed only half way upon the plate. As the plate cools, the dishes may be pushed over until they are entirely upon the hot plate. (14.) Rheostat for outside fat plate. Turning rheostat han- dle forward increases the temperature. Turning handle back- ward decreases the temperature. It is important to see that the lever on handle makes good contact with the separate buttons, and not with two buttons at a time. As soon as the right button has been found that maintains a constant temperature, mark this point upon the white plate. When starting up the Tester, the handle may be turned on full, and then when the temperature is up to within ten degrees of the right point, the handle may be turned back to the previously marked button. The same instruc- tions apply for all rheostats. (15.) Rheostats for the fat oven. (16.) Rheostats for the solids oven. (17.) Rheostat for the outside solids plate. (18.) Handle for the centrifuge. (19.) In case the operator forgets the temperature and time for treating the samples at the various points, the same may be noted below each snap switch for each hot plate. (20.) The power unit consists of a high vacuum pump, a water circulating pump, and a suction fan, all driven by a single motor. The vacuum pump must be submerged in oil furnished with the Tester. The pump chamber should be filled with oil up to mark upon the air cock. (21.) Automatic burettes. The cans holding the water, am- monia, alcohol, ethyl ether and petroleum ether are placed in this Parts 67 order. This is the order in which these reagents are added to the flasks containing the weighed sample of milk. The water and ammonia bottles are graduated to .50 c.c. divisions. The alcohol, ethyl ether and petroleum ether burettes are graduated to 5,0 c.c. divisions. (22.) Place this hood over the fat dishes when evaporating off the ether, so that the suction fan may draw ether fumes out- side of the building. (23.) Fasten these legs to the floor with lag screws. (24.) This side need not be fastened to floor. In case it is necessary to take out power unit, it is necessary only to disconnect connections in the rear of the machine, and move this part of the machine forward. (25.) The balance is the heart of the machine. Operator must keep it level, clean and handle it carefully. Raising and lower- ing knife edges must be done gradually and with care. Makg it a habit to clean the balance daily. The weights must be kept clean, and as soon as you notice that some of the smaller weights are wearing out, order new ones. (26.) This cock releases the vacuum upon the oven when cock (27) is closed. It must be kept closed when the vacuum is being maintained in the oven. (27.) This cock connects the vacuum oven upon the solids side with the main vacuum line leading to the vacuum pump. The set of cocks at the left is for the control of the vacuum to the fat oven. (28.) In top of fat plate holder there is a hole communicating with the suction fan upon the power unit. When the exhaust pipe connecting with the suction fan is run out of the laboratory, and the hood is over the dishes, all fumes of ether will be ex- hausted from the room. (29.) ScreM stool to floor, (30.) A wash stand for washing all glassware should be pro- vided. This should be properly designed and conveniently lo- cated, and supplied with both hot and cold water. In Fig. 19 is given a phantom view of the fat side of the Mo- jonnier Milk Tester which aids in a further understanding of the function and the arrangement of the various parts. The power 68 Asse;mbung Mojonnier Milk Tester unit, water tank, centrifuge with head, baskets and extraction flasks, and the device for exhausting the ether vapors are espe- cially pointed out. Fig*. 19. Phantom view fat side Mojonuier Milk Tester. Table 16. Dimensions and other eng'ineering' specifications coverlngr the Mojonnier IMUlk Tester. Floor Space Height Table Top Height Over all Shipping Weight H. P. Consumed Size of Wire Required Type Min. Max. Model D — For both fat and solids with thermostatic 56 X 82 in. 35 in. 68 in. 1,500 lbs. IH 3 12 Model A— For fat and solids with rheostatic control .... 48 X 82 in. 35 in. 68 in. 1,300 lbs. IH 3 12 Model G — For fat and solids with steam control 66 X 82 in. 35 in. 68 in. 1,400 lbs. 1^ 3 Pipe Inlet J^ in. Dimensions 69 ^ o 5 c ,2 c a? ■-H o CO .AJ a o r> CO o e ^ -4-) o a J5 s: ID S I 2 5 3 c .S o a g ^ t 3 u o C ri ^ m « c PO CO T3 c H 3 P 3 s ^ o CHAPTER V THE OPERATION OF THE MOJONNIER MILK TESTER 111 the Mojoiinier Milk Tester, there are several operations that remain the same regardless of the product that is being tested. The operator should become familiar with every detail covering the construction, care and use of the machine. General Care of the Tester. Keep the Tester clean and free from the accumulation of unnecessary materials at all times. It is impossible to do accurate work if the apparatus is not in the best of conditiou. All japanned parts can be cleaned either with engine oil, applied by a clean cloth, or by washing with good soap and water. THE POWER UNIT AND THE WATER CIRCULATING UNIT. Keep the water tank well filled with water. Add about one quart light machine oil to the water in the tank to keep the water pump well lubricated. If the Tester is located in a cold room in winter, add one gallon denatured alcohol to the tank to prevent freezing. Keep the vacuum pump chamber properly filled with the right kind of oil. The oil should just about reach the top of the pis- tons, as indicated by the gauge glass upon the side, or cock upon the end, in the earlier models. Give the motor proper care. It should receive the same atten- tion as is required by any motor, that is, it is to be kept cleaned, and well lubricated. Should any knocks develop upon the power unit, remedy the same immediately. The construction is very simple, and with a little study the care and operation of the power unit can be readily learned. [70] Adjusting Temperatures 71 THE VACUUM OVENS AND COOLERS. Keep sufficient mercury in the mercury well to insure good contact between the thermometer and the mercury well. The mercury well should rest directly upon the hot plate, otherwise incorrect temperature will be indicated by the thermometer. If mercury is spilled upon the hot plates, remove it at once. Do not permit mercury to come in contact with aluminum dishes as this may spoil the test. Keep the ground joint between the lid and the oven thoroughly cleaned. In case that it is difficult to get the proper amount of vacuum, look first to this place for trouble. Sometimes it may be necessary to use a small amount of vaseline, but as a rule the best results are obtained by keeping the ground joints thoroughly clean, using just enough vaseline to provide the proper lubrication and to prevent rusting. Be sure that the ther- mometer opening, and the openings upon the bottom of the oven are thoroughly sealed. It may be necessary to replace the rub- ber tubing at these points in case that leakage develops. Be sure to see that the cooling dessicators are kept from freezing tempera- tures. If the water in the cooling plates should freeze, it would ruin the plates. Watch the water coming out of the coolers, in order to be sure that the circulation is correct. Turning on the Current and Adjusting- Temperatures. It is important that the wires connecting with the Tester should be of size specified ; namely. No. 12 copper wire. The Tester is provided with a main control switch. Turn on the current to heat the out- side hot plates and the vacuum oven plates, by means of the snap switches. These are properly marked for the guidance of the operator. This should be done far enough in advance so that the plates and ovens will be heated to the proper temperature, when they are needed. The temperatures upon the outside plates in all electrically operated models, and in the vacuum ovens upon Model A, may be closely regulated by means of the rheostats. If the voltage is constant, the temperature will remain very near to the point desired for a long period of time after the rheostats have been properly adjusted. Ascertain by the tests just where it is necessary to hold tlie lever upon the rheostat in order to get the required temperature. After this point is once ascertained, the 72 OpE;RA'riNG Mojonnie:r Milk Tester lever can be set at the point required, and the temperature al- lowed to come up automatical!}^ when starting in the morning. In the case of Model D the temperature in the two vacuum ovens is controlled by thermostats. The method of wiring recom- mended is indicated upon Fig, 21. The mercury thermostat rest- ing in the mercury well is calibrated at the required temperature, and it must be properl}^ connected. Tig. 21. Wiring- Diagrams for Thermostatic Control Model D Mojonnier Tester. A For Direct Current. B For Alternating- Current. Care and Use of the Balance. Keep all parts of the balance and case free from dust. A cover placed over the balance at night serves a very useful purpose. Dust the balance including the pans and weights, using a camel's hair brush for this purpose. Level and adjust the balance so that the pointer will oscillate an equal number of divisions upon each side of zero upon the pointer scale. If the pointer swings too far to the right, turn the adjust- ing screw upon the beam to the right. If it swings too far to the left, turn the adjusting screw to the left. Two types of balances are in principal use : namely, the old type with graduated beam and rider, as illustrated under Fig. 22, and the new type called ''Chainomatic" with the chain and ver- nier, as illustrated under Fig. 23. The care to give to either type Operation op Balance 73 of balance is the same. The difference is in the method of balanc- ing the object to be weighed, and of reading the weight. These points will be discussed separately. A balance is a delicate instrument, and care needs to be exer- cised in its use at all times. The weights likewise require careful handling. Lack of care in the weighing operations may lead to entirely erroneous results, and thus defeat the object aimed at : namely, the accuracy of the tests. Tig. 22. Analytical Balance. Courtesy of Schaar & Co. The balance is enclosed in a glass case to shield it from dust, air currents and moisture. Perhaps the largest factor affecting accuracy in weighing, granting other conditions to be right, is temperature. If the vessel or object to be weighed is of a lower temperature than the balance case, it will weigh apparently more than its actual weight. If of a higher temperature than the bal- 74 Operating MojonniEr Milk Tester Fig". 23. Analytical Chainomatic Balance. (Courtesy of Christian Becker Co.) aiice case, it will weigh apparently less than its actual weight. The object should, therefore, be as closely as possible of the same temperature as that of the air in the balance case. The water cooled desiccator used upon the Mojonnier Tester has been de- signed primarily to facilitate the equalizing of the temperature between the dishes to be weighed and the balance case. See, there- fore, that the temperature of the water in the circulating sj^stem is as nearly as possible the same as the temperature in the balance case. The weights shonld be kept clean, and checked frequently either against each other, or against other standard weights. Promptly replace any weights that may be off the standard, or apply the necessary correction. Chainomatic Balance 75 When necessary to clean the chain, carefvilly detach it from the balance. Lay it out straight on a piece of velvet and brush it with a camel's hair brush. Then return it to its proper place on the balance. A small beaker partly filled with sulphuric acid should be kept in one corner of the balance case. Replace the sulphuric acid when it becomes saturated with moisture, and be very careful never to allow the beaker to overflow. Protect the balance against vibration, and see that it is in exact level. The air bubble in the spirit level should be in the exact center. This can be readily accomplished by means of the leveling screws under the balance case. The balance should be in exact equilibrium at all times. That is, the pointer should oscillate an equal number of divisions upon each side of zero upon the pointer scale. If the pointer swings too far to the right, turn the adjusting screw upon the beam to the right. If it swings too far to the left, turn the adjusting screw to the left. Place object to be weighed upon the left hand pan, and the weights or counterpoises upon the right hand pan. Handle the weights with the forceps only, using the right hand. Use the left hand to release the beam front the support, and to raise or lower the balance door. The weights should be placed upon the pan in a systematic order, begiiniing with a weight that is judged to be somewhat too heavy. liower weights are then tried in succession in a systematic order until equilibrium results. Upon the old style balance, adjustments under 5 and 10 milli- grams (depending upon the construction of the balance) are made by means of the rider. Keep the balance door closed while the final adjustment is being made. Determine the relation between the divisions upon the rider beam, and the pointer scale. This relation varies with different balances, but when once ascertained upon a given balance, it remains a constant value, and if applied in making a weighing, a great deal of time can be saved. For example, if the pointer oscillates six divisions to the right of zero, and four divisions to the left, with a balance having a relation of .0002 gram to one division upon the pointer scale, the rider is moved .0004 gram to the right to bring the balance into equilib- rium. 76 Operating Mojonnier Mii,k Tester Upon the Chainomatic Balance, adjustments under .0500 gram are made by means of the screw and vernier. Determine the rela- tion between the divisions upon the vernier, and the pointer scale. If the pointer swings too far to the right, lower the slide, — if too far to the left, raise the slide. About .0003 gram upon the vernier usually equals one division upon the pointer scale. Exercise great care in recording the weights. A double check should be made by reading both the weights upon the balance pan, and the weights that are missing from the set. The weights should be placed upon a paper near the front of the balance case, with the values of the weights marked upon the place where the respective weights are kept. Kemember that one misread weight will spoil an entire test. Upon the Chainomatic Balance read weights as follows : (a.) Sum of all grams weights equals whole number. (b.) Sum of 100 or multiple of 100 milligrams equals first decimal. (c.) Sum of 10 or multiple of 10 milligrams equals second decimal. Out of a possible total of 100 milligrams, 50 milligrams are obtained from the fractional weight, and 50 milligrams from the vernier beam. (d.) The third decimal is obtained from the vernier beam. Read the value of the line just above the small upon the slide. (e.) The fourth decimal is the value upon the slide that is in the exact line with any given line upon the vernier beam. THE IMPORTANCE OF SHORT BALANCE SWINGS. Much time can be saved by following the proper practice at each step of the weighing operation. Long balance swings con- sume more time : cannot be read so accurately, and the final result is usually not as dependable as when short swings are used. H. L. Wells^ made a careful study of the relative merits of long and short swings, and concludes in favor of the short swings. The best practice is to permit the pointer to swing between 4 and 6 points upon either side of the zero line. If the swings are much shorter than this, the error due to the width of the pointer may become considerable. Two complete oscillations only are neces- sary — the second being a check upon the first one. Every precau- Weighing // tion .should be taken to speed up the weighing in order that this may not affect the accuracy of the results. THE INFLUENCE OF TEMPERATURE UPON THE WEIGHING RESULTS. The temperature factor is too often disregarded. J. J. Mojon- nier weighed three aluminum dishes, size about 3" in diameter by 1" high at various temperatures. The results obtained are given in the following table : TABLE 17. Influence of Temperature Upon the Weight of Aluminum Dishes. Dish Number. Balance Temperature Wt. Dish at 32° F. Wt. Dish at 63° F. Wt. Dish at 68° F. Wt. Dish at 92° F. 4 3 2 68 68 68 10.0200 10.0110 10.0128 10.0126 10.0043 10.0029 10.0108 10.0028 10.0012 10.0000 9.9915 9.9900 This subject was further carefully studied by one of the authors at Cornell University.- The results of the experiments performed are given in Table 18. TABLE 18. Influence of Temperature Upon Analytical Weights of Various Objects. 300 c c. Aluminum dish 100 c. c. Aluminum dish 300 c. c. Erlenmeyer flask "J O OS o « CO ,a 50 c. c. platinum dish 7 aluminum discs clamped together i , S « a III C9 III in ti a to ci-2.| Wt. temperature 21.5° C 54.8882 13.5906 46.7769 49.2125 18.6343 57.7225 56.3290 56.2754 56.3222 Wt. temperature 80° C 54.8295 13.5700 46.7430 49.1624 18.6243 57.7168 56.2728 56.2658 56.2754 Decrease in weight due to increased temperature .0587 .0206 .0339 .0501 .0100 .0057 .0462 .0096 .0468 The results given in both of the preceding tables prove the importance of maintaining uniform temperatures between con- tainer and balance when weighing both the empty container and in turn the container, after the substance to be weighed has been added to it. The colder the object being weighed, the greater 78 Operating Mojonnitcr Milk Tester will be the weight thereof, and vice versa, the warmer the object, the smaller the weight thereof if the balance temperature remains constant. These facts, if not properly reckoned with, may cause large errors in results. With care, the same can be kept under close control. The principal causes of the above variations are : (a) The in- fluence of air currents set in motion because of the higher tem- perature of the object being weighed, (b) The displacement of air in the container, due to its expansion at the higher tempera- tures. In the experiment with the separatory funnel the loss in weight from this cause was about 4.6 times greater than the loss due to the air currents, (c) Other possible causes include the re- cording of incorrect weights ; slight differences in the length of the scale beam ; changes in barometric pressure ; changes in the temperature of the air in the balance between the weighings, and invisible moisture films upon the surface of the container. How to Heat the Fat and Solids Dishes Before Weighing^. Give to the fat and solids .dishes the same treatment before weighing them empty, that is given them before the final weighing in com- pleting a determination when they contain the extracted fat or the solids from the test. Place the clean fat dishes in the vacuum oven at a temperature of 135° C. Turn on the vacuum and leave them in the vacuum oven for 5 minutes. Transfer them to the cooling desiccator, and with the pump still running, leave them therein for 7 minutes before weighing. Be certain that the water is circulating through the plate in the cooling desiccator. Place the clean solids dishes in the solids ovens at 100^ C. Turn on the vacuum, and leave them in the vacuum oven with the vacuum on for 5 minutes. Transfer them to, and hold them in the cooling des- iccator for 5 minutes while the water circulating pump is running. Do not weigh either the fat nor the solids dishes far in advance of the time that the same may be required. The principle to keep in mind is the necessity of maintaining the same temperature in the balance ease at the time of the two weighings. How to Weigh the Fat and Solids Dishes. After the dishes have remained in the respective cooling desiccator for the proper time, they should be promptly transferred to the balance pan and weighed accurately to .0001 gram, using the proper counterpoise. Weighing 79 Record the weight and number of each dish in its respective place on the laboratory report sheet. Use cover upon solids dish. No cover is to be nsed with the fat dish. Return the dishes to the cooling: chamber, until needed for the test. How to Clean the Dishes and the Glassware. The solids dishes should be soaked in water after the test has been completed, and the solids then removed by hand, or by means of a brush suited to the purpose. They should then be thoroughly washed and dried, and placed in the vacuum oven until required for further use. Avoid the use of washing powders and alkalies for cleaning aluminum. The fat dishes should be treated with steam or very hot water until all traces of fat are removed, or they should be treated Avith a small quantity of gasoline until the fat is all dis- solved, and this treatment repeated for a second time. Finally, the dishes are to be cleaned with a dry cloth, and placed in the vacuum oven until needed. All glassware should be washed either immediately after beings used, or it should be placed in Avater until washed. Extraction flasks should be thoroughl}- washed with tap water, and then washed out with distilled water. If flasks become dirty, wash with washing powder and shot, or use washing powder with a brush specially designed for this flask. Clean pipettes with brush and water. Use washing powder, if necessary. Rinse successively with water, alcohol and ether, and then dry by holding at exhaust cock leading to the vacuum oven, or place upon the pipette holder between fat oven and cooler. REFERENCES. ' Wells, H. L., Analytical M'eighing, Jour. Am. Chem. Socl., Vol. 42. p. 411. 2H. C. Troy. CHAPTER VI SAMPLING DAIRY PRODUCTS When samples of milk, or any of its products, are taken for the purpose of examination or analysis, great care must be exer- cised in order to have the samples truly represent the average composition of the substance. In ordinary liquid dairy products, the fat globules rise toward the surface and form a layer of cream whenever the substances remain at rest. Other small particles of undissolved substance settle to the bottom. Many of the bacteria may be carried in either direction. For these reasons the product must be mixed until the different constituents are evenly distrib- uted throughout the entire mass. Then the sample must be taken immediately. ACCESSORIES REQUIRED FOR SAMPLING DAIRY PRODUCTS. To insure proper sampling it is necessary to use the proper tools. The following figures illustrate the apparatus recommended for properly sampling various dairy products. Fig. 24. Mojonnier Composite Sample Bottle, recommended for collecting and holding either com- posite samples, or any other samples to be tested. The advantages of this bottle are as follows : 1. The pure Para rubber stopper fits the mouth of the bottle tightly and prevents evaporation, and in consequence overreading of butter fat content. 2. No danger of dropping, misplacing or break- ing stopper. 3. The non-rust chain and copper ring always keep the stopper accessible for quick restoppermg. 4. Can be quickly opened with thumb of hand holding bottle, leaving other hand free for pouring in sample of milk. 5. Sample can be thoroughly shaken and mixed in the bottle without danger of loss. [80] Sampling Instruments 81 agfc-» [2)0:^ C^iS^ '■3^=53 Fig-. 25. Fig-. 26. Fig. 27. Fig. 28. Fig. 29. Fig. 25 illustrates milk thief. This is recommended only for sampling fluid milk, principally at the weigh can. If properly used it makes it possible to obtain composite samples that are representative of the entire lot of milk from which the samples were taken. Fig. 26 illustrates a small milk dipper, such as is frequently used for taking samples at the weigh can. Inasmuch as it holds a constant volume, it will not give representative composite samples unless the lots of milk are all of uniform weight. Fig. 27 illustrates the Scoville and McKay Samplers. These are extensively used for sampling both fluid milk and cream. Fig. 28 illustrates a common type of sampler for butter. Fig. 29 illustrates a satisfactory sampler for cheese. 82 Sampling Dairy Products SAMPLING FLUID MILK. Fresh milk or milk only a few hours old may be readily mixed by pouring it from one vessel to another a few times or by stirring it with a dipper or similar instrument having a handle sufficiently long to reach down to the bottom of the container. When the cream on the milk has dried until it is flaky or lumpy and part of it has become attached to the sides of the container, it may be softened by warming it to 95° F. or 100° F. before mixing. Frozen milk must be thawed to permit proper mixing before sampling. When the fat has separated so that it floats in small granules or in lumps on the surface of milk, it cannot be restored to its orig- inal flnely divided condition without warming the milk and pass- ing it through a homogenizer or viscolizer. The fat that separates is lost in ordinar}^ methods of sampling, but it rarely separates in cold milk that is free from acid. Therefore, it is to the advan- tage of milk producers selling on the fat test to keep their milk in good condition so that no fat will separate before the milk is tested. When sampling milk or its products for the purposes of stand- ardization, the method to use in collecting the composite sample must be determined by the conditions prevailing at each separate plant. In many cases, it may not be necessary to know the exact test of the milk, as the batch very frequently may be handled upon the basis of the results of the previous day, or by working with the finished product only, in which cases the composite sam- ple can be dispensed with. Three methods of sampling for the purpose of standardizing whole milk are available, as follows: (1.) At the weigh can. By taking out with a "milk thief" or other similar sampler, a proportional part of the milk from each weighing, just before letting out the milk. This method is likely to be very inaccurate whenever the milk is partly churned or partly frozen, or whenever the milk is improperly mixed in the weigh can. It has the further objection that it requires, as a rule, an extra man to collect the samples, which, of course, increases the operating expense to that extent. (2.) In the holding tank, after the milk has been thoroughly stirred. This is the ideal method, but it is seldom possible for a Sampijng Cream 83 plant to collect all the milk in one tank before starting the several standardizing operations. (3.) By means of a drip sample. The sample to be collected from the pipe leading out of the weigh can, or at some suitable place upon the pipe line. When possible to apply this method, it is probably the simplest and best method of all. However, care must be taken to see that the drip operates properly, and that it does not get clogged up. Also the sample must be properly pro- tected against evaporation and spoilage, since the sample may be collecting over a considerable period of time. A suggested method for collecting a drip sample is illustrated under Fig. 30. SAMPLING CREAM. The methods employed in sampling cream are similar in principle to those used in sampling milk. As cream is more viscous and flows less freely than milk, even more effort and care must be taken to insure correct sampling. When cream is sampled immediately after separating, the fat may be evenly distributed by thorough mixing and by pouring it a few times from one vessel to another. When the cream is coagulated or lumpy it should be passed through a wire sieve or strainer. In some cases it may be necessary to warm the cream enough to soften the fat before mixing in order to secure a homogeneous product. The sample may be taken from the container with a dipper or with a sampling tube. When the sample taken is to form part of a composite sample, the amount taken from each delivery should always bear the same proportion to the mass sampled. Neglecting to do this may be the source of large errors. COMPOSITE SAMPLES DEFINED. As applied to creamery work, a composite sample is made up of several portions of milk or cream from a single source, usually taken from different days' deliveries, and placed in a bottle with a preservative. In condenseries, ice cream plants and commercial milk plants where different dairy products are to be mixed to- gether, or where all of the products received from different Fig-. 30. Method of ol)- taining" drip sample from milk line. 84 Sampling Dairy Products sources are to be thus mixed, the term "composite sample" may refer to a mixture of aliquots (proportionate amounts) from each of the masses of substances that are to be united and standardized to a definite composition. It is seldom necessary to test composite fluid milk samples oftener than once a week. Usually they are tested once in two weeks. Where possible to preserve them properly the ideal method is to test them once a month. This reduces the amount of testing to a minimum, saves unnecessary labor and increases accuracy. PRESERVATIVES FOR COMPOSITE SAMPLES. The principal preservatives used for keeping composite sam- ples in good condition are mercuric chloride (corrosive sublimate), formaldehyde, and potassium bichromate. The use of mercuric chloride has generally given good results. It can be purchased in tablet form combined with substances that color the milk pink or blue to warn people against drinking it as this preservative is a deadly poison. Two or three of the tablets serve to preserve six or eight ounces of milk for a period of two weeks. Formaldehyde is also successfully used for preserving compos- ite samples where other preservatives do not completely check growth of moulds. It is not such a deadly poison as mercuric chloride, but milk samples containing it should be marked "poi- sonous." Five or six drops of a 40% solution of formaldehyde will preserve six or eight ounces of milk over a period of two weeks. "Composite test liquid" is a form of formaldehyde spe- cially prepared and colored, for keeping composite samples. It is the most economical and the most satisfactory preservative now in use. Potassium bichromate is not as effective a preservative as the others named, but it serves well for holding samples for short periods. It is poisonous but not so severe as mercuric chloride. For preserving milk samples enough of the bichromate is added to give the milk a lemon-yellow color. CARE OF COMPOSITE SAMPLES. The samples should be kept in trays or on shelves in a cool cupboard near the weighing can. Each bottle and its location on the shelf should be plainly and correspondingly numbered. Composite Samples 85 When milk is added the bottle should be shaken with a rotary motion to soften and to reincorporate, without churning, any cream that has risen, and to bring the freshly added milk in con- tact with the preservative in solution. The cupboard should be closed and locked when sampling is completed for the day. PREPARING COMPOSITE SAMPLES FOR TESTING. Even with the best care, some cream will become attached to the sides of composite sample bottles. Therefore, it is always advisable to place the bottles in warm water to soften the cream so that it may be quickly removed from the side of the bottle. When necessary a suitable brush, or spatula, having a piece of rubber tubing drawn over the lower end, can be used to loosen the cream from the sides of the bottle. The cream can then be readily reincorporated. The contents of the bottle should not be heated above 100° F., or part of the fat will separate as an oil, and make it extremely difficult to secure an accurate test sample. By bringing the water in the warming vessel to a temperature of about 100° F. and then placing the bottles in the water, there will be little danger of overheating. Figure 31 illustrates a water bath espe- cially designed to heat composite sample bottles before testing. It is provided with a steam spray pipe, and an overflow so that exact control can be maintained over this operation. Tig. 31. Composite Sample Bottle Water Bath. To properly mix the cream with the milk and obtain repre- sentative samples, the addition of a small quantity of shot to the bottle before heating and shaking will insure a satisfactory emul- COMPOSITE CREAM SAMPLES. The practice of taking composite samples of cream has nearly ceased in recent years, as more accurate results are secured by 86 Sampunc. Dairy Products testing each sample the day it is taken. With such a valuable product as cream, the higher degree of accuracy secured by the daily test offsets the additional expenses. When composite sam- ples of cream are taken, the directions given above for composite milk samples will apply in every detail. SAMPLING SKIM-MILK. Skim-milk should be mixed before sampling in the same man- ner as whole milk. Samples taken from a separator spout at a single instance usually will not show the average composition of the total quantity separated. After separation is completed, pro- portionate amounts should be taken from each container and mixed together. The test secured on such a mixture will be the average of the entire mass. The same should be kept in air tight sample jars in a cool place until they are tested. SAMPLING WHOLE MILK FOR MAKING EVAPORATED MILK, OR SWEETENED CONDENSED MILK. In addition to the directions given on pages 82-83 for sam- pling whole milk, the following will be of assistance in sampling when testing, in evaporated or condensed milk plants. Secure samples from the holding tanks after the milk has been thoroughly stirred. This is the ideal method, but it is seldom possible for a plant to collect in one tank all the milk required to make up one batch. In some cases, more than one holding tank is available, and the same can be filled alternately with the whole milk. Sam- ples are taken out of the alternate tanks in the proportion of 1 c.c. to each one hundred pounds of milk in the tank. For exam- ple, a tank holding eight thousand pounds of milk will require an 80 c. c. sample. Samples from the different tanks that go to make up the entire holdover l:)atch can be mixed together before testing the same for fat and total solids. The objection to this method is that it is seldom possible to allow the milk to accumulate in the tanks in any fixed quantity since it is usually necessary to pump it into the hot wells as soon as it starts accumulating in the hold- ing tanks. At the hot wells : If the samples are taken at the hot wells, care must be taken that no milk remains in the wells from the previous batch. Also care must be taken that the milk be well stirred be- Sampling Condensed Milk 87 fore the sample is taken, and that the sample taken be propor- tional to the entire weight of milk in the different hot wells. This is a good method, provided the milk in the hot wells can be prop- erly stirred, but it cannot be used in the case of sweetened con- densed milk, on account of the sugar remaining in the hot wells. SAMPLING EVAPORATED MILK AND SWEETENED CONDENSED MILK. Evaporated milk requires to be sampled and tested both before and after sterilizing. Samples taken from a pan batch should be collected in a well-stoppered bottle as illustrated under Fig. 24. The sample should be promptly cooled to about room temperature and well mixed before testing. Where the holdover sj^stem is used, great care must be taken to secure proper mixing of the entire lot of milk in the holdover tank. The method of agitation used should be proved by testing samples taken from different parts of the holdover batch. Samples after sterilizing should be properly mixed in the can. Samples in which the butter fat has separated or has become churned require special attention, and it frequently becomes im- possible to make an accurate test on account of the mechanical condition of the sample. Skimmed or whole unsweetened condensed milk are usually sampled in a manner similar to evaporated milk. Sweetened condensed milk in its several varieties is a product that requires very particular care in sampling. A sample from a pan batch should be collected in a well-stoppered bottle and promptly cooled. A sample from a large holdover batch should be taken only when the agitation is complete. Samples taken from cans, or from barrels, require particular attention on ac- count of the possibility of the milk sugar settling upon the bottom of the containers. Unless the milk sugar is thoroughly reincor- porated, it becomes impossible to obtain a test that is representa- tive of the original milk. SAMPLING FOR ICE CREAM MIX. Methods for sampling cream and other materials to be used in compounding the ice cream mix will be found under the directions for sampling the respective products. The methods of sampling the mix to determine its composition will vary according to the 88 Sampling Dairy Products conditions peculiar to each plant. Where a homogenizer is used, some operators prefer to take the sample from the cooling coils a few minutes after the homogenizer has started. The mix is then in excellent condition for sampling. Other operators may prefer to take the sample from the pasteurizer before homogenizing. In the latter case, care should be exercised to make certain that the mixture is homogeneous throughout. When neither pasteurizer nor homogenizer is used, dependence must be placed upon ordi- nary methods of mixing to prepare the batch for sampling. Three ounce or four ounce samples of the mix should be taken with a sampling tube or dipper and placed in air-tight, glass sample bottles until tested. SAMPLING THE FROZEN PRODUCT. There is some tendency for the heavier substances to descend, and for the fat percentages to increase in the upper layers of ice cream held in storage. Therefore, care must be exercised in order to secure representative samples. Where the mass is large the sample may be taken with an instrument like a butter trier, draw- ing a column of the ice cream extending from the top to the bot- tom of the container. Bricks of ice cream may be sampled by drQMdng plugs with a trier or preferabl.y by taking the whole of a ' vice about half an inch in thickness across the brick, and at le'-'st an inch from the end. Frozen samples should be melted gradually before testing. SAMPLING RUTTER. The sampling of butter is one of the most important and diffi- cult operations in the process of determining its composition. This is so because the water and salt are not evenly distributed throughout the fat. The moisture content of the butter in one end of a churn will be different from the content in the other end. The fat percentage near the surface of a tub of butter, or the surface of a pound print, will be higher than it is at the bot- tom of the tub or at the center of the pound print. For these reasons, care and judgment must be used in taking the sample. The method of sampling varies according to the condition and location of the butter. When sampling butter in the churn, take with a spatula or butter knife ten or twelve one-fourth ounce •portions from different parts of the churning and place them to- SaMPIvING Chi^sse 89 gether in a glass sample jar that has an air-tight stopper. If the butter is in tubs, the sample may be taken with a butter trier. It is best to take drawings — one from near the edge, one halfway between the edge and the middle, and one from the middle. The different drawings are placed together in a sample bottle. Some- times after the cover is removed the tub is turned upside down and lifted off the butter. A one-half pound wedge-shaped piece of the butter is then taken from one side about half-way between the bottom and the top. Prints may be sampled by tak- ing two or three drawings with a trier or by taking a three-ounce slice across the print about an inch from one end. SAMPLING BUTTERMILK. In sampling buttermilk, use the same methods and precautions that are given for sampling whole milk and skim-milk on pages 82-85. SAMPLING CHEESE. The percentage of moisture in cheddar and other hard cheese is highest near the center, while the percentage of fat and other solids is highest near the outside. For these reasons considerable care and skill is required to take a truly representative sample without destroying the cheese. The moisture determination given in Table 19 was compiled by one of the authors. It gives the distribution of moisture in a cheddar cheese at intervals over a period of twenty-one days after the cheese was taken from the press and while it was on the shelves in a fairly cool curing room. The cheese was not coated with paraffine. TABLE 19. The Distribution of Water in a Cheddar Cheese and the Loss of Water by Evaporation. Results Obtained by Prof. H. C. Troy. Age of cheese. Inner third of the plug. Middle third of the plug. Outer third of the plug. Average. 1 day 37.57 36.78 35.69 36.65 3 " 36.90 36.43 35.08 36.13 7 " 36.81 36.59 34.95 36.11 9 " 36.50 36.62 35.00 36.04 11 " 36.56 36.55 34.50 35.87 14 " 36.54 36.49 34.45 35.82 17 " 36.30 36.39 34.41 35.66 21 " 36.47 36.44 34.10 35.67 90 Sampling Dairy Products The simplest and best method to take a sample of a cheddar cheese is to cut out a wedge-shaped piece reaching from the cir- cumference to the center. The sample should be placed immedi- ately in a sample jar having an air-tight stopper. When it is necessary to take samples without destroying the cheese, draw from the upper side with a cheese trier, — three plugs, one about one inch from the outer rim, one at the center and one half-way between the other two. The plug should extend half- Avay through the cheese. After drawing the plugs, break off a piece of each plug at the outer end, and close the openings with them. The remainder of the plugs will serve as the sample, and they should be placed in the sample jars, and the jars closed at once. Disc-shaped soft cheese may be sampled by taking a wedge- shape piece extending from the rim to the center. Square-shaped soft cheese are sampled by taking a slice across the cheese some distance in from one end. Samples of hard cheese like cheddar are prepared for testing by passing them through a meat chopper or by cutting the cheese into particles about the size of kernels of wheat. This may be done in the sample bottle by using the end of a table knife that has been squared and sharpened. Before taking the final test portion, the contents of the bottle should be well mixed. The soft cheese sample is prepared for testing by mixing it in the sample bottle, using a spfitula or knife blade for this purpose. Excellent results are obtained by grinding the sample in a close-grained mortar with a pestle. This must be done rapidly so that there may be no loss of moisture from this operation. SAMPLING WHEY. Whey should be well mixed before sampling. The absence of large amounts of casein permits the fat in whey to rise quickly. It is practically impossible to reincorporate all of the fat that rises to the surface, and for this reason fat tests of whey usually show less rather than more fat than the whey contains. Also the particles of .casein settle to the bottom quickly and carry down with them any incorporated fat. The manufacturing processes of Sampling Powdered Products 91 numerous varieties of cheese are influenced by the percentage of acids in the whey. For this reason alone the whey has to be sam- pled and tested for acidity frequently during the advancement of the manufacturing process. In the process of manufacturing cheddar cheese, the whey is sampled immediately before heating the curd, previous to removing the whey, and while the curd is piled, before being milled, and finally also before salting. As test samples of whey are usually taken by volume, the most satisfactory way is to take them Avith a graduated pipette from the mass to be sampled immediately after it is mixed. It may then be transferred directly to the vessel in which the test is to be com- pleted. If a sample bottle is used much of the fat may be lost by becoming attached to the sides of the bottle. SAMPLING OTHER CONCENTRATED DAIRY PRODUCTS. When exposed to the air, milk powder absorbs moisture rap- idly. This makes thorough mixing of the sample especially nec- essary when the powder is not kept in moisture proof containers. When it is kept in cans it should be well mixed, and if lumps are present it should be put through a sieve before mixing. Some- times the powder is mixed, then divided into four approximately equal parts. Portions from each quarter are then mixed to- gether and the sample, taken, or the quartering process may be carried further. Sampling Whole Milk Powder. Whole milk powder is sampled in the same manner as skim-milk powder. Sampling- Malted Milk. Malted milk is sampled by the method given for sampling skim-milk powder. Sampling- Milk Chocolate. Milk chocolate cannot be ground to a powder as it will soften into a paste in the process. Therefore it must be shaved or grated into fine particles to permit thorough mixing before taking a test sample. Frequently the chocolate can be pounded to a smooth, homo- geneous mass, in a mortar, with a pestle. 92 Samsung Dairy Products Sampling' Cocoa. Since cocoa is usually held in the form of a powder, it may be sampled by the methods given for sampling milk powder. CHAPTER VII DIRECTIONS FOR MAKING FAT TESTS, USING THE MOJONNIER TESTER OUTLINE OF METHOD. The method for making fat tests upon the Mojonnier Tester is a comparatively simple one. It is modified for various dairy products, but the principles and the general operations remain unchanged. In the case of fresh milk the method in brief is as follows : Measure 10 grams of milk into the extraction flask illustrated under Fig. 32. Add 1.5 c. c. of ammonia and mix in small bulb of flask. Add 10 c. c. of 95 per cent alcohol, insert cork and shake thoroughly. Add 25 c. c. of ethyl ether, and shake for 20 seconds. Then add 25 c. c. petroleum ether and shake for 20 seconds. Place the extraction flask in the holder of the centrifuge and turn the handle 30 turns, taking about one-half minute. This will give a speed of 600 revolutions per minute. The centrifuge with the holder is illustrated in Fig. 19, Chapter IV. Pour off the ether solution from the remainder of the liquid into the fat dish. Evapo- rate the ether from the dish, illustrated under Fig. 33. Pigr. 32. Fat Extraction Flask. Tig. 33. Fat Dish. Repeat the extraction, adding in turn with thorough shaking after each addition, 5 e. c. of alcohol, 15 c. c. of ethyl, and 15 c. c. of petroleum ether. Centrifuge as before. Add water if neces- sary to raise the dividing line between the ether solution, and the remaining liquid residue. Pour off the ether solution into the ' [93] 94 MojoNNiER Fat Test same dish as was used for the first extraction. Evaporate the ether from the dish. Dry the fat in the vacuum oven. Cool and weigh the dish. Calculate the percentage of fat in the sample. The necessary modifications of the above method for the vari- ous dairy products will be discussed further in this chapter. The successive steps involved will also be discussed in careful detail. HOW TO WEIGH THE SAMPLES FOR THE FAT TEST. Several methods are in use for weighing the samples for the fat test, depending upon the product that is being tested. The weighing cross with the short pipettes can be used successfully upon a number of dairy products. Numerous advantages are gained by using the cross, provided the product to be tested permits of its use. Five different samples can be weighed with only six weighings, and if care is taken, great accuracy is obtain- able. The following cuts illustrate just how the weighing pipettes and the weighing cross are used. GIO ^^=^ Q9 G8 G7 T28A TaSB rifft 34, Weig-hing' Cross with Rubbers and Pipettes. Also lO-grram Fipettet Pipettes 95 G 7, G 8 and G 9 illustrate 1, 2 and 5 gram pipettes, respective- ly. G 10 is a pipette graduated to deliver 10 grams of whole milk, and it is never used in connection with the weighing cross, T 28 illustrates the cross itself, with the arms all properly numbered, in order to distinguish between the samples. T 28A shows the cross with the rubber tubes inserted over the knobs, thus forming an air-tight seal. T 28B shows the pipettes inserted in the tubes. Another very satisfactory method of weighing certain dairy products is b}^ means of Weighing Pipettes. These are illustrated under Fig. 35. G51 G52 G53 T116 Fig-. 35. Weig-hlngr Pipettes with Holder. G 51, G 52 and G 53 illustrate 1, 2 and 5 gram pipettes, respectively. T 116 illus- trates the holder that is to be placed upon the balance pan with the pipettes. With this method also, five samples can be weighed with only six weighings. Fig-. 36. Position of Weig-h- Ing' Pipette Before Placing- in Holder. 96 MojoNNiER Fat Te;st Products that are not homogeneous or that separate rapidly, are weighed most accurately when placed directly into the extrac- tion flask, while the latter is suspended to the arm of the balance. This is illustrated under Fig. 37. Right Way Wrong Way Pigf. 37. — Plask Hangrer with Plask Suspended to Balance Arm. Fig. 38 is a hanger, one end of which is fastened to the hook upon the balance arm and the other holds the flask around its neck. To insure absolutely accurate results, the extraction flask at the time of weighing must have the same tem- piask Hang-er. perature as that of the balance case, and the weighings of the empty flask and the flask when it contains the sample must be made quickly and closely together. In order not to expand the air inside the flask between the weighings, the flask should not be held in the hands nor allowed to change temperature by any other means. Adding Reage;nts 9; Butter, and all other products that are not hygroscopic, are weighed with great accuracy in the butter boat illustrated un- der Fig. 39. n: Fig-. 39. Butter Boat. The butter boat is weighed empty, the sample is then placed in it, and the weight obtained by difference. Several products can be pipetted out, taking ten grams and where possible, this is a very accurate method. The pipettes are graduated to discharge ten grams of whole milk at 60° F., allow- ing 15 seconds for draining the pipette after the milk has all run out, and then blowing out the last drop of milk in the pipette. WEIGHT OF SAMPLES TO TAKE FOR THE FAT TEST. The size of sample to use varies, depending upon the product being tested, and it ranges from one gram in the case of butter to ten grams in the case of raw milk. See instructions following each product, and also Table 21 at the end of this chapter. HOW TO ADD THE REAGENTS. The reagents should be added in the follow- ing order : Water, am- monia, alcohol, ethyl ether, and petroleum ether, The burettes upon the dispensing cans are gradu- ated to deliver the proper charge re- quired. See instruction under each prod- uct, and also Table 21 at the close of this chapter. Fig. 40 shows position of flask when adding reagents, when one or two tests are being made. Fig. 41 on next page shows pref- erable metliod of adding reagents when sev- Fig*. 40. Adding- Reagents ^^'^^ Samples are to be tested. 98 MojoNNiER Fat Test Pig-. 41. Correct Position of Plask Holder and Plasks for Adding- Be> ag-ents When Making- Pour Tests at One Time. HOW TO SHAKE THE FLASK. If only one sample is being tested, it can be shaken by hand. As many as four samples can be shaken at one time in the holders which are furnished with the equipment. The flask should be held with large bulb down (see Fig. 42), and the small bulb extending upward. In this position they are shaken vigorously lengthwise of flask. After shaking 5 or 6 times, allow liquid in small bulb to run back into large bulb. Repeat this operation at least four times. There is no "danger in shaking the samples too much. The only danger is in not shaking the samples enough so that this is a very impor- Pig-. 42. Correct Position of Plask When Shaking-. Mixing Rkagents 99 tant part of the operation. Fig. 43 illustrates the extraction flask holder by means of which four samples can be shaken at one time. The flasks should be kept in the position indicated while shak- ing and the liquid allowed to flow alternately from the large to the small bulb. Fig'. 43. Illustrates the Position in Which to Hold the Four Flasks That Are Being Shaken at One Time. HOW TO CENTRIFUGE THE FLASK. If only one sample is being centrifuged at a time, place a coun- terpoise upon the opposite side of the centrifuge in order to bal- ance the head. Always see that there is about the same weight upon both sides of the centrifuge. The centrifuge with the head, holder and flask is illustrated under Fig. 19, Chapter IV. HOW TO POUR OFF THE ETHER SOLUTIONS. Remove the cork by twisting it carefully from the flask. Pour off the ether solution as completely as possible, taking care not to allow any of the liquid under tlie ether to flow out of the flask. This can be avoided if the dividing line between the ether solu- tion and the remaining solution is carefully Avatched, while pour- ing off. In the first extraction, a larger amount of the ether so- lution can remain in the flask than in the second extraction. The 100 MojoNNiER Fat Test correct procedure in pouring off is illustrated under Fig, 44. The fat dish should be placed upon the tester top, and the opera- tor should look down upon the ether solution as it is being poured off, observing the point where all the ether has been removed. By following this method, all but one or two drops of the ether solution should be re- moved, provided the dividing line was in the right place before pouring out. Pigr. 44. Correct Procedure When Pourings Ether Solution Into Dish. HOW TO BRING UP THE DIVIDING LINE Inability to pour off the ether solu- tion closely is due to the fact that the dividing line between the ether solu- tion, and the remaining solution is too low in the lower bulb of the flask. At the end of the first extraction, the dividing line can re- main without change, taking care to pour off the ether solution as closely as possible, re- gardless of the posi- tion of the dividing line. At the end of the second extraction, remove the stopper from the flask, and drop sufficient distilled water from the burette into the extraction flask to raise the dividing line to the desired point. This should be done just before pouring off the ether. If this procedure is followed, it becomes possible to remove the ether almost to the last drop. Fig, 45 shows the position of the dividing line both before and after water is added. After Before Figr. 45. Position of Dividing' £ine Before and After Baising. Evaporating Ether 101 HOW TO EVAPORATE THE ETHER FROM THE DISH. It is important to maintain the proper temperature upon the outside hot plate. If the temperature is allowed to go below 135° C, it takes too long to evaporate the ether solution. Upon the other hand, if it rises much above 135" C, there is danger of the ether boiling out over the top of the dish, and also slight danger of oxidation of the fat. If the plate is too hot, it is best to place only part of the dish in contact with the plate. It is recommended that the hood be placed over the dishes, and that the ether fumes be blown out of the room by means of the blower. It is dangerous to allow the ether fumes to evaporate into the work- ing room, and besides it makes it very unpleasant for the operator to work in contact with these vapors. This method is illustrated under Fig. 46. Fig'. 46. Evaporating the Ether. Fig. 47. Transferring" Dishes to Vacnum Oven, 102 MojoNNiER Fat Test HOW TO HEAT THE FAT DISH IN THE OVEN. Do not transfer the fat dish from the outside hot plate to the vacuum oven until all of the ether has been evaporated. If this is not done, the contents of the dish are quite likely to spat- ter in the oven. It is very important to maintain proper tempera- ture conditions, namely 135° C, and also the proper vacuum upon the fat dishes, while the same are being heated in the oven. If for any reason, there should be difficulty in attaining either the proper heat, or the proper vacuum, the trouble should be immedi- ately investigated and its cause removed. Wrong W^ay Right Way Fig". 48. Method of Flacingr Dish Upon the Balance Fan. HOW TO WEIGH THE FAT DISH. The fat dishes are to be transferred from the vacuum oven to the cooling desiccator in which they are to remain for seven min- utes before being weighed. The weighing should be done as promptly as possible after cooling. Allow as little time as possible to elapse between the weighing of the empty dish, and of the dish with the fat in it. The air in the cooling desiccator should be at the same temperature as the air in the balance case. Therefore the two should be located closely together. CoNTROLtINC THK VaCUUMS 103 DIRECTIONS FOR OPERATING LEVERS CONTROLLING THE VACUUM OVENS. L f i- 1 Tig. 49. Valve Handles Controlling' Vacuums in Fat and Solids Ovens Move valve handles in positions corresponding to lettering in above diagram as follows : For no vacuum in eitlier oven.... A, B and C, D For vacuum in fat oven A^ B and C, D^ For vacuum in Solids oven A, B^ and C\ D For vacuum in botli ovens A, B^ and C, D^ 104 MojoNNiER F'at Test IMPORTANT HINTS TO OPERATORS OF THE MOJONNIER MILK TESTER. FiiT- 50 When Fillingr Water Tank Use Bub- taer Tube and Siphon Water as Illus- trated. A Iiittle Water Soluble Oil Placed in the Water Will Prolong' Iiife of Gears in Water Circulating^ Fump. Fig. When Filling Vacuum Pump Reservoir Fill Spouted Dipper Fur- nished with Tester and Four as Il- lustrated Until Proper Iievel of Oil is Indicated in Oil Gauge. Fig-. 52. Place the Calcium Chloride Fan Under the Plate In the Cooling Desiccator, as Illustrated. Laboratory Re;port 105 HOW TO RECORD THE RESULTS AND TO CALCULATE THE PERCENTAGE OF FAT. A systematic method should be adopted for recording all data covering the fat tests. Pig. 53 shows a form of laboratory report suitable for recording both fat and total solids tests. LABORATORY REPORT ^r 1 1 ... 1 1 j rj.^r 1 1 r.«TTM 1 1 1 -i. 1 1 i 1 1 -= — 1 1 1 1 1 ! ! I 1 1 ! 1 1 1 1 '"".IIW"' 1 1 1 ! 1 i i 1 1 1 1 1 1 i ,oI. 1 1 ! 1 o«™« Fig-. 53. Iiaboratory Report Blank. Dish plus Fat Dish Fat TABLE 20. Laboratory Report. Test No. 1 September 1, 1920. Evaporated milk. 4287 0163 4124 Pipettes plus Sample 32.8200 Pipettes 27.6650 Sample 5.1550 Percentage of Fat 8.0000 Evaporated milk. .2550 Dish plus Solids Dish 0124 Solids 2426 Dish or Pipette, plus sample. .9401 Dish or Pipette 0124 Sample .9277 Percentage of Solids 26.1500 In order to obtain the per cent of fat in the sample, divide the weight of the fat in the dish by the weight of the sample taken. Multiply the result thus obtained by 100 or move the decimal point 106 MojoNNiER Fat Tkst two places to the right. Example : Weight of fat found equals ,4124 gram. Weight of sample taken equals 5.1550 grams. .4124 divided by 5.1550 equals .0800. .0800 multiplied by 100 equals 8.00 or the percentage of fat in the sample. HOW TO RUN BLANKS UPON REAGENTS. ■ It is of the utmost importance to use pure reagents, or to make the proper corrections when using reagents that contain impurities. To prove the purity of the reagents, blank determinations should be made at frequent intervals. Measure 50 c. c. each of ethyl and petroleum ether in separate fat dishes. Evaporate, heat, cool and weigh the dishes in exactly the same manner as when making a fat test. The residue should not exceed .0005 gram, which is equal to an error of .01 per cent upon a five gram sample. In a second method measure 10 c. c. of water in a fat ex- traction flask, and add all the reagents and complete the test just as in the case of a fat test upon whole milk. The residue in this case also should not exceed .0005 gram. If the residue exceeds the above limits, trace the trouble to the particular reagent that is responsible for the residue present, and take immediate steps to correct the trouble. Refer to Chapter III. HOW TO TEST FRESH MILK, SKIM-MILK, WHEY AND BUTTERMILK FOR FAT. Mix the samples very thoroughly. Measure samples for the test, taking 10-gram sample and using the 10-gram pipette. Drain the pipette 15 seconds, counting from the time the milk has all run out. Then gently blow out the last drop. If it is preferred, the samples can be weighed, although this constitutes an unneces- sary operation. Add no water to the samples. For the first extraction, add 1.5 c. c. of ammonia ; 10 c. c, of alcohol ; 25 c. c. of ethyl ether, and 25 c. c. of petroleum ether. Shake thoroughly after the addition of the ammonia, half a minute after the addition of the alcohol, and one minute after the addi- tion of each of the two ethers. Centrifuge 30 turns, taking one-half minute. For the second extraction, add neither water nor ammonia. Evaporated Milk Test 107 Add 5 e. c. of alcohol ; 15 c. c. each of ethyl and petroleum ethers, and shake 20 seconds after the addition of each reagent. Centrifuge 30 turns, taking one-half minute. If necessary to raise the dividing line between the two ether solutions, add the necessary distilled water just before pouring off. After evaporating off the ether, heat the dishes with the fat, in the vacuum oven at 135° C. for five minutes with not less than 20" of vacuum. Cool in cooling desiccator to room temperature for seven minutes. Weigh rapidly. Record results and calculate the percentage of fat. HOW TO TEST EVAPORATED MILK, CONDENSED BUTTERMILK AND ALL UNSWEETENED CONDENSED MILKS FOR FAT. Unsweetened condensed milk or evaporated milk, whether un- sterilized or sterilized is all tested for fat in yery much the same manner. Superheated plain bulk condensed is difficult to sample properly, so that great care must be exercised in getting represen- tative samples. Evaporated milk sterilized in the can, especiall.y after standing for a considerable time sometimes contains the fat, either separated in the form of cream or in the form of churned fat. Samples in this condition are difficult to test, and the proper allowance should always be made in cases of this kind. To weigh the sample use either the weighing cross, or the weighing pipettes, and in some cases it may be desirable to weigh the sample directly into the flask suspended from the balance arm. The last method would apply where the samples are not homo- geneous. Use about 5-gram sample, excepting in the case of con- densed buttermilk and of extra heavy superheated milk, when only 3 grams should be used. For the first extraction, add 4 c. c. of water (except in the ease of condensed buttermilk and of extra heavy superheated milk when 6 c. c. of water should be used). 1.5 c. c. of ammonia, 10 c. c. of alcohol, and 25 c. c. each of ethyl and petroleum ethers. Shake thoroughly after the addition of water ; again after adding the ammonia ; half a minute after the addition of the alcohol and 20 seconds after the addition of each of the two ethers. Centrifuge 30 turns, taking one-half minute. 108 MojoNNiER Fat Test kill ill i.liii! ' For the second extraction, add neither water nor ammonia. Add 5 c. c. of alcohol, 25 c, c. each of ethyl and petroleum ethers, and shake 20 seconds after the addition of each reagent. (In the ease of plain condensed skim-milk, and condensed buttermilk, use only 15 c. c. of each ethers in the second extraction.) Centrifuge 30 turns, taking one-half minute. If necessary to raise the dividing line, add the necessary dis- tilled water just before pouring off the ether solution in the sec- ond extraction. After evaporating off the ether, heat the dish with the fat in the vacuum oven at 135° C. for 5 minutes with not less than 20 inches of vacuum. Cool in the cooling desiccator to room tem- perature for 7 minutes. Weigh rapidly. Record results, and calculate the percentage of fat. HOW TO TEST SWEETENED CONDENSED MILK FOR FAT. Proceed without diluting the sample, but be sure to obtain a representative sample, and to make sure that the sample is prop- erly and thoroughly mixed. Sweetened condensed milk is very difficult to sample properly on account of the tendency for the milk sugar to settle out. To weigh the sample, use either the weighing cross, or the weighing pipette. Use about five grams sample. For the first extraction, add 8 c. c. of hot water; 1,5 e. c. of ammonia ; 10 c. c. of alcohol, and 25 c. c. each of ethyl and petro- leum ethers. Shake very thoroughly after adding the water, and again after adding the ammonia, and one minute each after adding the alcohol, and the two ethers. Centrifuge 60 turns, taking one minute. For the second extraction, add neither water nor ammonia. Add 5 c. c. of alcohol, 25 c. c. each of ethyl and petroleum ethers, and shake 20 seconds after the addition of each of the reagents. Centrifuge 60 turns, taking one minute. If necessary to raise the dividing line, add the necessary dis- tilled water just before pouring off. After evaporating off the ether, heat the dish with the fat, in the vacuum oven at 185° C. for 5 minutes, with not less than 20 inches of vacuum. Cool in the cooling desiccator for 7 minutes. Ice Cream Mix Test 109 "Weigh rapidly. Record results and calculate the percentage of fat. HOW TO TEST ICE CREAM MIX FOR FAT. Mix the sample very thoroughly, and if necessary heat the same slightly in order to melt the butterfat. If the sample is not homogeneous, great care must be exercised in weighing out the same, otherwise the accuracy of the results will be affected. Weigh the sample, using either the weighing cross or the weighing pipettes, and in case that the sample is not homogeneous, weigh the sample directly into the extraction flask suspended from the balance arm. Use about five grams sample. For the first extraction, add 5 c. c. of water, 1.5 c. c. of ammo- nia, 10 c. c. of alcohol, and 25 c. c. each of ethyl and petroleum ethers. Shake thoroughly after adding water, and again after adding the ammonia, and one-half minute each after adding the alcohol and the two ethers. Centrifuge 30 turns, taking one-half minute. For the second extraction, add neither water nor ammonia. Add 5 c. c. of alcohol, 25 c. c. each of ethyl and petroleum ethers, and shake 20 seconds after the addition of each reagent. Centrifuge 30 turns, taking one-half minute. If necessary to raise the dividing line, add the necessary dis- tilled water just before pouring off the ether solution. After evaporating off the ether, heat the dish with the fat, in the vacuum oven at 135° C. for 5 minutes with not less than 20 inches of vacuum. Cool in the cooling desiccator at room tem- perature for 7 minutes. Weigh rapidly. Record results and calculate the percentage of fat. HOW TO TEST CREAM FOR FAT. Mix the sample very thoroughly, and heat it slightly, if this should be necessary, in order to melt the fat. To weigh the sam- ple, use either the weighing cross or the weighing pipettes, and if the sample is not homogeneous, use either the butter boat or weigh the sample directly into the extraction flask suspended on the bal- ance arm. In the case of cream testing less than 25 per cent of fat, use two grams sample, and in the case of cream testing more than 25 per cent of fat, use one gram sample. no MojoNNiUR P'at Test For the first extraction, add 5 cc. of water, in the case of cream testing less than 25 per cent. Add 6 c. c. of water, in the case of cream testing more than 25 per cent of fat. Shake thor- oughly after the addition of the water. Use also 1.5 c. c. of ammonia, 10 c. c. of alcohol, and 25 c. c, each of ethyl and petroleum ethers. Shake thoroughly after the addition of the ammonia ; one-half minute after the addition of the alcohol, and 20 seconds after the addition of each of tlie two ethers. Centrifuge 30 turns, taking one-half minute. For the second extraction, add neither water nor ammonia. Add 5 c. c. of alcohol, 25 c. c. each of ethyl and petroleum ether, and shake 20 seconds after the addition of each reagent. Centrifuge 30 turns, taking one-half minute. If necessary to raise the dividing line, add the necessary dis- tilled water just before pouring off the ether solution in the sec- ond extraction. After pouring off, heat the dish with the fat in the vacuum oven at 135" C. for five minutes with not less than 20 inches of vacuum. Cool in the cooling desiccator to room temperature for seven minutes. Weigh rapidly. Record results, and calculate the percentage of fat. HOW TO TEST MALTED MILK, MILK CHOCOLATE, COCOA, CHEESE AND BUTTER EOR FAT. Follow the method of sampling recommended under each of these products in turn under Cha*pter VI. To weigh the samples in all cases, use either the butter boat or weigh directly into the ex- traction flask suspended from the balance arm. In the case of malted milk, chocolate and cocoa, use .5 gram sample. In the case of cheese and butter, use 1.0 gram sample. For the first extraction, add 8 c .c. of hot water, 1.5 c. e. of ammonia (3 c. c. in case of cheese), 10 c. c. of alcohol, and 25 e. c. of each ethyl and petroleum ethers. Shake thoroughly after the addition of the water and the ammonia; one-half minute after the addition of the alcohol, and 20 seconds after the addition of each of the two ethers. Centrifuge 30 turns, taking one-half minute. Milk PowdUr TiiST 111 For the second extraction, add neither wator nor ammonia. Add 5 c. c. of alcohol, 25 c. c. each of ethyl and petroleum ether and shake 20 seconds after the addition of each reagent. Centrifuge 30 turns, taking one-half minute. If necessary to raise the dividing line, add the necessary dis- tilled water just before pouring off the ether solution in the sec- ond extraction. After evaporating off the ether, heat the dish with the fat in the vacuum oven at 135° C. for five minutes with not less than 20 inches of vacuum. Cool in the cooling desiccator for seven minutes. Weigh rapidly. Record results and calculate the percentage of fat. HOW TO TEST SKIM-MILK POWDER, BUTTERMILK POWDER, AND WHOLE MILK POWDER FOR FAT. Follow the method of sampling recommended under these products in Chapter VI. To weigh the sample, use either the but- ter boat or weigh directly into the extraction flask suspended from the balance arm. Use about 1 gram sample. For the first extraction, add 8.5 c. c. of hot water, 1.5 c. c. of ammonia (3 c. c. in case of buttermilk), 10 c. c. of alcohol, and 25 c. c. each of ethyl and petroleum ether. Shake thoroughly after adding water, again after adding ammonia, one-half minute after the addition of the alcohol, and 20 seconds after the addition of each of the two ethers. Centrifuge 30 turns, taking one-half minute. For the second extraction, add neither water nor ammonia. Add 5 c. c. of alcohol, and shake for 20 seconds. In the case of skim-milk powder, and buttermilk powder, add 15 c. c. each of ethyl and petroleum ether. In the case of whole milk powder add 25 c. c. each of ethyl and petroleum ether. Centrifuge 30 turns, taking one-half minute. If necessary to raise the dividing line, add the necessary dis- tilled water just before pouring off the ether solution, in the sec- ond extraction. After evaporating off the ether, heat the dish with the fat in the vacuum oven for five minutes with not less than 20 inches of 112 A^IojoNNiER Fat Test vacuum. Cool in the cooling desiccator at room temperature for seven minutes. Weigh rapidly. Eecord results and calculate the percentage of fat. ORDER OF OPERATIONS IN TESTING EVAPORATED MILK FOR BUTTERFAT AND TOTAL SOLIDS WITH THE MOJONNIER TESTER. In the following outline, the procedure described is that used in the case of evaporated milk. The procedure used in the case of other products is much the same, but as mentioned both in Chap- ter VI and elsewhere in this chapter, differences may occur in the methods of sampling the products ; of weighing the samples ; the size of the samples to use ; the quantity of water- or other reagent to add; the method of shaking, and the method of centrifuging. The outline presumes that only one operator is doing the work. When speed is required, a helper to the operator can materially shorten the time required. In that case, the order of operations will need to be slightly modified. 1. Place the respective dishes in the vacuum ovens and keep them therein for at least five minutes, while the ovens are heated, with the vacuum on. 2. Transfer the respective dishes to the cooling desiccators ; turn on the pump, and set the bell for five minutes for solids, and seven minutes for fat. 3. Weigh the solids dish first, being careful to put the cover upon the dish, and record the weight and the number, upon the laboratory report. Put the dish back into the cooling desiccator. 4. Weigh the fat dish without the cover. Record the weight and the number upon the laboratory report, and put the fat dish into the cooling oven. 5. Fill one 5 gram and one 1 gram pipette with milk, and place them upon the weighing cross, or weighing rack, or pref- erably, weigh the solids sample directly into the solids dish. 6. Weigh the above and record the weight upon the labora- tory report upon the line entitled ''pipettes plus sample." 7. Transfer the milk in the 5 grams pipette to the extraction flask, and return the empty pipette to the weighing cross, or to the weighing rack. Order of Operations 113 8. Weigh again, and record the weight in the fat column upon the line entitled "pipettes." 9. Also record the above weight in the solids column of the laboratory report, upon the line entitled "dish or pipettes plus sample." This operation may be omitted if the solids sample is weighed directly into the solids dish. 10. Transfer the milk from the one gram pipette to the weighed solids dish, and return the pipette to the weighing cross, or to the weighing rack, or preferably, obtain the weight of the solids sample by weighing it directly into the solids dish. 11. Place the weighing cross or the weighing rack upon the balance ; weigh, and record the weight upon the line entitled ' ' dish or pipette." This operation may be omitted if the solids sample is weighed directly into the solids dish. 12. Add sufficient distilled water to the milk in the dish to make a total volume of 2 c. c. of liquid. Mix and distribute even- ly, and place the dish upon the solids hot plate. 13. When evaporation has taken place, transfer the dish to the solids oven. 14. Turn on the vacuum, and set the bell for ten minutes. 15. At this point take the extraction flasks with the milk in the same, and make the first extraction. Centrifuge, and pour the ether into the fat dish. 16. Make the second extraction, same as under 15. 17. During the above period, the solids bell will ring, and the solids dish should be transferred to the cooling desiccator, and the bell set for five minutes. 18. As soon as the ether has evaporated, place the dish in the fat oven ; turn on the vacuum, and set the bell for five minutes. 19. When the bell for the solids side rings, weigh the dish, and record the weight. 20. When the test bell for the fat side rings, transfer the dish to the cooling desiccator, and set the bell again for seven minutes. 21. Complete the subtractions upon the laboratory report. 22. Weigh the fat dish ; turn off the motor, and finish the calculations. 114 MojoNNiHR Fat Test 23, From the tests obtained, determine what material to add to standardize the batch. LIST OF PRECAUTIONS TO OBSERVE IN MAKING FAT TESTS UPON THE MOJONNIER TESTER. (1.) Before the reagents are put into the cans, the cans should be throughly cleansed by washing all parts, first with warm wa- ter, then with alcohol and finally with ether. Every third or fourth time that the cans are filled, empty out the last portion of the reagents, and use the same for cleaning purposes, unless tests prove the same to be of proper quality. (2.) The bottom of all dishes should be kept as flat as possi- ble. Any bulging should be worked out by resting the dishes upon the marble plate, in front of the balance, and rubbing the entire surface with the thumbs. The operator should observe this every time that the dishes are cleaned. This is very impor- tant. (3.) The calcium chloride in the cooling desiccators should be changed every three or four weeks. The same calcium chloride may be used over and over, by drying the moist calcium chloride in the tin dishes by placing the same upon the hot plate held at 135'^ C. for at least five hours. However, the better method is to use a fresh supply, as soon as the supply in the desiccators be- comes saturated. (4.) The bottles should be whirled in the centrifuge until the ether extraction is perfectly clear. About 30 turns in half a min- ute is recommended. For sweetened condensed milk this time must be doubled. (5.) Be sure to keep the extraction flasks perfectly clean. Wash often with sulphuric acid and washing powder, if neces- sary. If particles cling to the sides, put in small shot, washing powder and hot water, and shake thoroughly. (6.) Keep the temperature regulated as near to standard temperature as possible. (7.) Never pour off the ether solution into a hot dish. Re- move the dish from the plate before the second extraction is run into the dish. Precautions 115 (8.) Be careful to pour off the ether into the dishes slowly at first, and gradually increase the stream. (9.) In using the weighing pipettes, make sure that the neck of the flask is free from water when the pipette is inserted. (10.) Always use clean and dried pipettes. POSSIBLE CAUSES EOR HIGH FAT TESTS. If the results upon fat are higli as compared with the check results, the cause may be one or more of the following : (1.) Not keeping the bottom of the dishes flat. (2.) Improper shaking and centrifuging shoAvn by non-fatty residue in the dish. (3.) Impure reagents. (If in doubt, run test upon reagents substituting water for milk.) (4.) Temperature in fat oven too low. (5.) Dirt has gotten into the dish after the ether was poured into it. (6.) Improper reading or posting of weights. Weights have lost weight from use. (7.) Weighing the dish containing the fat at a lower tem- perature than prevailed when the dish was weighed empt.y. POSSIBLE CAUSES FOR LOW FAT TESTS. If the results on fat are Ioav as compared with check results, the cause may be one or more of the following : (1.) Leaky corks. Use best corks obtainable. (2.) Insufficient shaking. (3.) Adding too much water, or too little alcohol. (4.) Having dividing line too low, so that too much ether is left behind. If such is the case, add more water to bring the line to the proper height, before pouring off, or make a third extrac- tion. 116 MojonniEr Fat Test ;S Co o o. OH 2^ 3-^ w-^- as O M* ^ ■ u o « aj gw fe-a s "^ « Scn-a « (S o"- 2w WW o o »o o I ^11 H oj W Q ^ a « 03 ^ « 2 w w a r/) c Q O s °' a °3 WW O OJ Sla U 03 C3 12 =3 g s-a 5^ S §=3 1^ sS 2 •9S^ 5 M'^'W i-S 3 iasw 5.9 =»'^ I*' a Summary of Operations 117 ' - » 90 min. in ovenatlOO°C or 20 min. and deduct 0.30% from total. 5 niin. in cooling desiccator at room temp. 10 min. in oven at 100° C.5 min. in cooling desiccator at room temp. - - - ' - - M e-j ^ c M - - O o o o o o o ' ' ' o 9 ' ^ 3 ' ^ » - - o a> a ^11 ^ » ' - 3 o a) a "Is ^ ' > ' ' » > ^ ' 5 ' §2 to a » °l - ^ ^ ' ' ^ ^ a - » ' ' ^ » 3 - ^ ' » ' ^ 10 CO Shake one minute ^ ' 10 CO Shake half minute ' ' a ^ ^ - - g.2 3 cS2 o 3 ' .a o .J3 o J3 o -a 8cc hot water. Mix until thoroughly dissolved ' 6cc hot water. Mix thoroughly 8cc hot water. Mix thoroughly ' ^ "3 _oco <1 Jo < Jo 1^ < 1- 3 ^ 1- ' ' ' :s » If fluid use weighing pipette otherwise use butter boat 3 Shake in can or mix in bulk very thoroughly .as. ' Proceed without diluting. Mix very thoroughly - - Pulverize in close grained mortar. Transfer to sealed jar - S Is Bulk Unsweetened Condensed Milk Bulk extra heavy Unsweetened Condensed Milk |g^ v-a's MO Condensed Milk with Sugar and Chocolate "Sis "g u .isl eg ^ 118 MojoNNiER Fat Test METHODS FOR MAKING TOTAL SOLIDS OR MOISTURE TESTS Summary of Operations — Weigh directly into dish upon balance M 20 min. in ven at 100° . 5 min. in cooling esiccator at oom temp. ^ » = min. in ven at 100° 5 min. in cooling esiccator at 3om temp. w-^-=^g OQ T3 ^ " °d ^ =^ ° o-S g 0, C-1 0. (M ^2; •g1t£°S.Sg l|lll|lS CO d 03 d 10 d o > ^■"'^ K, o fco-tj £? & , fe -S s .S.S -2I i^js m " ' ' ^ '°sz f£w to add, an Second E: dd neithe: ammonia lTj '^ WW = ^ ' = m " '0 fl§ J3 =. = cS o'-S < 1 ^■"•E 0) bc-S '=0 WgS^ "■ I ^ -gW ^ - ' ' QJ P-, M C3 ■>.& J3 J3 " '' '^ " ^ i.g WW - = ^ =8 c a o.a o.s J s.s -a , _>. >> °E "5 u .d 3 ja mf^ f^ bO Lh! I^" 5 K bD ^1 -!2 B a a ^S £ ' ' 0.— P « ^r' (S < J= ■g ^? « "> g^i ^ =3 ^ i" 3 =• w'^l fS S g Ml ^.S ill (Vj g -^ _^ be l-" "310 p »c p p .Sd .So -od ^^ .0 cc °.S < < < c4 ^ m W o- 1-1 ^°^ -0 g 'p m " PRliCAUTlONS 119 (5.) Too high temperature in the vacuum oven. (6.) Insufficient water circulating through the cooling desic- cator. The water tank must be kept filled, and the circulating pump must be kept in good working order. (7.) Improper reading or posting of weights. (8.) Spattering of the fat in the oven due to transferring the dish to the oven before the ether solution had all evaporated, or if too high heat is carried in the vacuum oven. (9.) Weighing the dish at a higher temperature than pre- vailed when the dish was weighed empty. The following summary contains all the essential facts neces- sary for making both fat tests and total solids tests when using the Mojonnier Tester. This is arranged so the operator can tell at a glance just how to proceed when testing any given dairy product. For the convenience of the operator the table gives informa- tion regarding total solids tests which are covered in Chapter VIII, to which the reader is referred. CHAPTER VIII DIRECTIONS FOR MAKING TOTAL SOLIDS TESTS USING THE MOJONNIER MILK TESTER OUTLINE OF METHOD. The method for making total solids tests taking fresh milk as a typical example is in brief as follows : "Weigh about 2 grams of milk in the flat bottomed three inch diameter by one inch high aluminum dish, as illustrated under Fig. 54. Spread the milk in a thin film over the entire bottom of the dish. Place the dish in direct contact with the outside hot plate, having a tempera- ture of as near 180° C. as possible. Hold the dish upon the plate until the first trace of brown begins to appear. Now transfer the dish to the vacuum oven having a tem- perature of 100° C. Keep the dish in the oven for 10 minutes under a vacuum of not less than 20 inches. Transfer to the cool- ing desiccator, and hold it there for five minutes, with the water circulating pump operating continuously. "Weigh rapidly. Record the Aveights and calculate the percentage of total solids. Such modifications of the above method, as may be necessary in the case of various dairy products will be discussed further in this chapter. The successive steps involved in the entire method will now be discussed in careful detail. HOW TO WEIGH THE SAMPLES FOR THE SOLIDS TEST. The samples for the solids test can be weighed by means of the weighing cross, or the weighing pipette, as described under Chap- ter VII. In many cases it is best to weigh the samples directly into the solids dish, as illustrated under Fig. 55 on next page. The method of weighing that has been found by experience to give the best results, is recommended under each separate product. [120] Weighing the Sample 121 Fig-. 55. Welgrhingf the Solids Sample, WEIGHT OF SAMPLE TO TAKE FOR SOLIDS TEST. The weight of sample required varies from .25 gram in the case of sweetened condensed milk, to 2.00 grams in the ease of whole milk. It is very important to adhere as closely as possible to the size of sample recommended in the case of each separate product. The use of too large a sample will very likely cause high results. Too small a sample may introduce inaccuracies, and may cause either too high or too low results. HOW TO HANDLE THE DISHES AFTER THE SAMPLES HAVE BEEN WEIGHED IN THE SAME. The dishes with the samples after weighing, if not convenient to treat immediately upon the outside hot plate, should be placed either upon the marble plate which supports the balance, or they should be transferred to the cooling desiccator. In no case should they be kept upon the outside hot plate support, as that causes evaporation, and makes it subsequently difficult to mix properly with water. Water should be added to the samples, where neces- sary, as soon as possible after weighing, and the test carried through without stopping between the various operations. HOW TO ADD WATER TO THE SAMPLES IN THE SOLIDS DISH. When necessary to add water, always use the best distilled wa- ter. It is well to run a blank upon the water to determine if it is free from solid matter. Eeject any water that may contain any solid matter. Add sufficient water to make up a total volume that 122 MojoNNiER ToTAi. Solids Tkst should not exceed 2 c, c, in the ease of the great majority of prod- ucts. Mix the sample with the water in the dish, so that the con- tents will be distributed uniformly over the bottom of the dish. In the case of several of the dairy products, this important opera- tion requires considerable skill and care. The necessary precau- tions will be found in the paragraphs describing the method of testing the various products. HOW TO TREAT THE SAMPLE UPON THE OUTSIDE SOLIDS HOT PLATE. It is very important to have the outside hot plate as near 180° C. as possible. If a temperature of more than 180° C. is used, there is great danger of the sample spattering out of the dish. If a temperature of less than 180" C. is used, the operation will be re- tarded, and the substance dries in the form of a smooth crust from which it is difficult to remove the last remaining traces of water. Heat the sample in the dish until it just begins to turn brown. This is one of the most important steps in the entire operation, and unless properly watched an error may be introduced at this point. Insufficient heating may give high results, and over-heating may give low re- sults. Use the dish contact maker illustrated under Fig. 56, to press the bottom of the dish upon the hot plate. The dish should be so manipulated that vigorous boiling takes place upon tlie entire surface of the bottom Pigr. 56. Disli Contact |' ^i, i-^i. Maker. Used to Press the ^'^ ^'^ ai^ii. Dish Against the Hot Plate. TEMPERATURE AND VACUUM TO MAINTAIN IN THE SOLIDS OVEN. Keep the solids oven at a temperature as near 100° C. as pos- .sible. This applies to all products to be tested. Also see that there are at least 20 inches of vacuum upon the vacuum oven. If the Tester is properly operated, it should be possible to maintain 25 inches of vacuum at all times. If for any reason, such for example as breakdown of the motor, it should be impossible to operate the power unit, the test can be completed in one and one-half liours without vacuum. If a Treatment of Souds Dish 123 vacuum of less than 20 inches only is obtainable, the time of holding the sample in the oven should be proportionately in- creased. As a general rule, the recommendation is as foUoAVs, in the case of products where the standard is 10 minutes : A'acuuin upon solids oven in How lono to k eep dishes in oven inches. under corres londing vacuum. - 20 to 25 10 minutes 15 to 20 20 " 10 to 15 30 " 5 to 10 40 " no vacuum 90 *' HOW LONG TO RETAIN THE DISH IN THE SOLIDS OVEN. This varies with the product to be tested. Tlie minimum time is 10 minutes, and in the case of sweetened condensed milk, in order to get absolute results, it is best to dry the samples one and one- half hours. HOW TO COOL THE SOLIDS DISH. Promptly transfer the dish from the oven to the cooling desic- cator, and keep it therein for five minutes, with the water circulat- ing daring this time. HOW TO WEIGH THE SOLIDS DISH. Always weigh the solids dish with the dish cover upon the dish. Make the weighings as rapidly as possible, as otherwise the sam- ple is quite likely to absorb moisture from the atmosphere. As in the case of the fat tests, a systematic method should be adopted for recording all data pertaining to the solids tests. A satisfac- tory blank report is illustrated under Fig, 53, Chapter VII, HOW TO CALCULATE THE PERCENTAGE OF TOTAL SOLIDS. Divide the weight of the total solids by the weight of the sam- ple taken, and multiply the result by 100, or move the decimal point two places to the right, which will give the percentage of to- tal solids in the sample. Example. Weight of solids found equals .2426 gram. Weight of sample taken equals 2.0216 grams. ,2426 -^ 2.0216 = .1200 .1200 X 100 = 12.00, or the per cent of total solids in the sample. 124 MojoNNiER Total Solids Test HOW TO TEST FRESH MILK, SKIM-MILK, WHEY AND BUTTER- MILK FOR TOTAL SOLIDS. Follow the directions of sampling given in Chapter VI. To weigh the sample, use either the weighing cross, or the weighing pipette, using the 2 grams pipettes, or weigh the sample directly into the dish upon the balance pan. Use about 2 grams sample. Add no water. Spread the milk in a thin film over the entire bot- tom of the dish. Now place the dish in direct contact, upon the outside hot plate, which should have a temperature of 180'^ C, and heat the dish until the first traces of brown begin to appear in the residue. Transfer the dish to the vacuum oven at a temper- ature of 100° C. Keep in the vacuum oven for 10 minutes under not less than 20 inches of vacuum. Transfer to the cooling desic- cator, and hold it there for 5 minutes with the water circulating, pump operating continuously. "Weigh rapidly. Record weights, and calculate the percentage of total solids. HOW TO TEST EVAPORATED MILK AND ALL UNSWEETENED CONDENSED MILKS, INCLUDING CONDENSED BUTTERMILK FOR TOTAL SOLIDS. Follow the directions of sampling given in Chapter VI. To weigh the sample, use either the weighing cross, or the weighing pipettes, using the one gram pipettes, or weigh the sample directly into the dish upon the balance pan. Use one gram sample in all eases, except in the cases of extra heavy superheated plain bulk condensed milk and condensed buttermilk, in which cases .50 gram sample should be taken. Add one c. c. of water to the sample in the dish in all cases, excepting in those of extra heavy superheated plain bulk condensed milk and condensed buttermilk, in which cases 2 c. c. of water should be added. Mix the milk and added water and spread in a thin film over the entire bottom of the dish. Now place the dish in direct contact upon the outside hot plate at a temperature of 180° C, and heat the dish until the first traces of brown begin to appear in the residue. Transfer the dish to the vacuum oven at a temperature of 100° C. Keep in the vacuum oven for 10 minutes under not less than 20 inches of vacu- um. Transfer to the cooling desiccator, and hold it there for five minutes with the water circulating pump operating continuously. Swe;e;te;ne;d Condensed Milk 125 Weigh rapidly. Eecord weights, and calculate the percentage of total solids. HOW TO TEST SWEETENED CONDENSED MILK FOR TOTAL SOLIDS. Follow the directions of sampling given in Chapter VI. To weigh the sample use either the weighing cross or the weighing pipette, taking one gram pipette, or weigh the sample directly into the dish upon the balance pan. It is usually most convenient to use the same pipette that was used for weighing out the sample for the fat test. When this is done, it becomes unnecessary to use an additional pipette for handling the solids sample. Use about .25 gram sample. This amounts to about four to five small drops. These drops should be placed in different parts of the dish so that the milk can be more readily dissolved by the water which is to be added later. Add 2 c. c. of hot water. Sweetened con- densed milk is comparatively slow in dissolving. It is very im- portant to make a good mixture of the milk with the water, and to spread the milk in a thin film over the entire bottom of the dish. When this is done, the dish should be placed in direct contact with the hot plate, having a temperature of ISO'^ C. Heat the dish un- til the first traces of brown begin to appear in the residue. Trans- fer the dish to the vacuum oven at a temperature of 100° C. Keep in the vacuum oven for 20 minutes under not less than 20 inches of vacuum. This method, however, does not effect complete drying, and it is necessary to deduct .30 per cent from the total solids ob- tained. For example : If the total solids are found to be 73.86 per cent when the sample was dried for 20 minutes, the .30 should be deducted which will give a net content of 73.56 per cent total solids. The results obtained with this method are almost identical with the results obtained when the sample is kept in the vacuum . oven for 90 minutes under not less than 20 inches of vacuum, and without making any deductions from the results obtained by dry- ing for 90 minutes. This method is recommended particularly for factory control work where the element of time is so important, while the second method is recommended where the element of time is of no consequence. In either method, transfer the dishes to the cooling desiccator at the end of the drying period, and hold it in the desiccator for five minutes with the water pump operat- 126 MojoNNiER Total Solids Tkst ing continuously. Weigh rapidly. Eecord weights and calculate the percentage of total solids. On account of the small sample taken, and the general difficulties in the way of sampling and test- ing sweetened condensed milk, every possible precaution must be exercised in the testing of this product. HOW TO TEST ICE CREAM MIX FOR TOTAL SOLIDS. Follow the directions of sampling given in Chapter VI. To weigh the sample use either the weighing cross or the weighing pipette, or weigh the sample directly into the dish upon the bal- ance pan. In any case, use about one gram sample. Add 1 c. c. of water. Spread the ice cream mix with the added water in a thin film over the entire bottom of the dish. Now place the dish in direct contact upon the outside hot plate having a tempera- ture of 180" C, and heat the dish until the first traces of brown begin to appear in the residue. Transfer the dish to the vacuum oven at a temperature of 100'^ C. Keep in the vacuum oven for 10 minutes under not less than 20 inches of vacuum. Transfer to the cooling desiccator, and hold it there for five minutes with the water circulating pump operating continuously. Weigh rapidly. Record weights, and calculate the percentage of total solids. HOW TO TEST CREAM FOR TOTAL SOLIDS. Follow the directions of sampling given in Chapter VI. To weigh the sample, use either the weighing cross, or the weighing pipette, using the two grams pipette. It is frequently necessary to weigh the sample directly into the dish upon the balance pan, or to weigh it in the butter boat. The method of weighing se- lected is to be governed by the mechanical condition of the sample to be tested. In the case of cream testing less than 25 per cent of butterfat, use one gram sample. In the case of cream testing more than 25 per cent of butterfat, use .50 gram sample. In the. case of cream testing less than 25 per cent of fat, add 1 c. c. of water to the sample in the dish. In the case of cream testing more than 25 per cent of fat, add 1.5 c. c. of water. Spread the milk with the added water in a thin film over the entire bottom of the dish. Now place the dish in direct contact upon the outside hot plate having a temperature of 180° C. and heat the dish until the first traces of brown begin to appear in tlie residue. Place jMiscellankous Products 127 in the vacimni oven for 10 minutes under not less than 20 inches of vacuum. Transfer to the cooling desiccator, and hold it there for five minutes with the water circulating pump operating continuously. Weigh rapidly. Record weights, and calculate the percentage of total solids. HOW TO TEST MALTED MILK, MILK CHOCOLATE AND COCOA FOR TOTAL SOLIDS. Follow the directions of sampling given in Chapter VI. Weigh the sample directly into the dish upon the balance pan. Use about .30 gram sample. Add 2 c. c. of hot water. Spread the sample with the added water in a thin film over the entire bottom of the dish. Now place the dish in direct contact upon the out- side hot plate having a temperature of 180° C. and heat the dish until the first traces of brown begin to appear in the residue. Transfer the dish to the vacuum oven having a temperature of 100° C. Keep in the vacuum oven for 20 minutes under not less than 20 inches of vacuum. Transfer to the cooling desiccator, and hold it there for five minutes with the water circulating pump operating continuously. Weigh rapidly. Record weights, and calculate the percentage of total solids. HOW TO TEST CHEESE FOR TOTAL SOLIDS. Follow the directions of sampling given in Chapter VI. Weigh the sample directly into the dish upon the balance pan. Weigh with the dish and the sample, a blunt pointed glass rod that can be used to break up any possible lumps of cheese that may later appear in the dish. Use about .50 gram sample. Add 1.5 c. c. of hot water. Spread the cheese with the added water in a thin film over the entire bottom of the dish. Use the glass rod to break up any lumps. Now place the dish in direct contact upon the outside hot plate having a temperature of as nearly 180° C. as possible, and heat the dish until the first traces of brown begin to appear in the residue. Transfer the dish to the vacuum oven having a temperature of 100° C. Keep in the vacuum oven for 20 minutes under not less than 20 inches of vacuum. Transfer in the cooling desiccator, and hold it there for five minutes with the water circulating pump operating continuously. Weigh rapidly. Record results, and calculate the percentage of total solids. 128 MojoNNiER Total Solids Test HOW TO TEST BUTTER FOR TOTAL SOLIDS. Follow the method of sampling recommended in Chapter VI. Weigh the sample directly into the dish upon the balance pan. Use about one gram sample. Add no water. Heat the dish in di- rect contact upon the outside hot plate, having a temperature of 180° C. until spattering ceases, or until the first traces of brown begin to appear in the residue. Transfer the dish to the vacuum oven having a temperature of 100° C. Keep in the vacuum oven for 10 minutes under not less than 20 inches of vacuum. Transfer to the cooling desiccator and hold it there for 5 minutes with the water circulating pump operating continuously. Weigh rapidly. Kecord results and calculate the percentage of total solids. HOW TO TEST SKIM-MILK, WHOLE MILK POWDER AND BUTTERMILK POWDER FOR TOTAL SOLIDS. Follow the directions of sampling as given in Chapter VI. Weigh the sample directly into the dish upon the balance pan. Use about .3 gram sample. Add 2 c. c. of hot water and spread the sample with the water in a thin film over the entire bottom of the dish. Now place the dish in direct contact upon the out- side hot plate having a temperature of 180° C, and heat the dish until the first trace of brown begins to appear in the residue. Transfer the dish to the vacuum oven having a temperature of 100° C. Keep in the vacuum oven for 10 minutes under not less than 20 inches of vacuum. ^ Transfer to the cooling desiccator, and hold it there for 5 minutes with the water circulating pump oper- ating continuously. Weigh rapidly, record results, and calculate the percentage of total solids. POSSIBLE CAUSES FOR TOO HIGH SOLIDS TESTS. (1). Bottoms of dishes were not kept flat. (2). Evaporation upon the outside solids hot plate had not been carried far enough, or it had been done at an improper tem- perature. Do not remove dish until all visible moisture is off, or until the first trace of brown coloration appears. (3). Improper reading or recording of weights. Weights have lost weight from use. (4). Dirt had fallen into dish after sample had been weighed into it. Causes of Inaccurate Tests 129 (5). Temperature in the vacuum oven was too low. (6). Vacuum was not up to standard. (7). Too large a sample was taken, rendering it impossible to remove all the water under the conditions recommended. (8). "Weighing the dish with the solids in the same at a lower temperature than prevailed when the dish was weighed empty. POSSIBLE CAUSES FOR TOO LOW TOTAL SOLIDS TESTS. (1). Sample was browned too much upon the outside hot plate, due either to too long exposure or to the use of too high temperature upon the hot plate. (2). Temperature in the vacuum oven was above 100° C. (3). Milk spattered from the dish. This will not happen if the temperature is kept at 180° C. (4). Improper reading or recording of the weights. (5). Water was not running through the cooler. (6). "Weighing the dish with the solids in the same at a higher Temperature than prevailed when the dish was weighed empty. SUMMARY OF METHODS RECOMMENDED FOR TESTING ALL DAIRY PRODUCTS FOR TOTAL SOLIDS. For this summary the reader is referred to Table 21 at the close of Chapter VII, This gives in a condensed form all the im- portant information required, covering the making of total solids tests when using the Mojonnier Tester. CHAPTER IX GENERAL INFORMATION REGARDING THE STANDARDIZING OF DAIRY PRODUCTS STANDARDIZATION DEFINED. Standardizing is defined as "comparing with a standard, or rendering standard." As applied to the dairy industry, it has a very broad application, inasmuch as it is used with reference to methods of plant operation ; the processing of various dairy prod- ucts and the physical, chemical and bacteriological limits permis- sible under a wide variety of products and conditions. In this book the emphasis is placed upon the standardization of the chemical constituents with especial reference to the fat and the solids not fat content of dairy products. These are the most important constituents of all dairy products both from a chem- ical and a commercial standpoint, inasmuch as they affect both the quality and the cost of the finished products. Consideration will also be given to the standardization of products added in the manufacture of certain dairy products, such as the addition of sugar when manufacturing sweetened con- densed milk, or of sugar and gelatin when making ice cream. Standardization is usually understood to mean either the rais- ing or the lowering of either or of both the fat or solids not fat content of all dairy products to a certain fixed standard. In practice it is possible to standardize either the fat or the solids not fat alone, or the two constituents together in the same product. Where the two constituents are standardized, the same will be present in the finished product in a constant ratio, one to the other. Methods will be given for standardizing various dairy products under the two conditions named. [130] Preliminary Operations 131 SUCCESSIVE STEPS INVOLVED IN STANDARDIZING. (a). When standardizing for one constituent only. The steps involved when standardizing a single constituent are as follows : (1). Obtaining a representative composite sample of the en- tire lot of product which makes up the batch, and likewise of the skim-milk or cream which might be used in standardizing. (2). Testing all of the above products for fat or total solids, depending upon the constituent to be standardized. Where ac- curate results are desired, these tests should be made upon the Mojonnier Tester. (3). Calculating the weight of each product to be used, by methods which will follow, and mixing the products together in the proper proportions. (b). When standardizing for both fat and total solids. The steps involved in standardizing dairy products for both fat and S. N. F. are as follows : (1). Obtaining a representative composite sample of the en- tire lot of milk which goes to make up the batch, and likewise of skim-milk and the cream which might be used in standard- izing. (2). Testing of all of the above products involved, for both fat and S. N. F. or T. S. by means of the Mojonnier Tester, ex- cepting that in the case of cream the S. N. F. can be obtained by referring to Table 22 found in this chapter, instead of by actual test. (3). Calculating the weight of each product to be used by methods which will follow, in order to bring the fat and S. N. F. to the same ratio that they are to have in the standardized prod- uct that it is desired to make. If the resulting product should be over the desired standard, the necessary water is to be added to bring it back to the required test. METHOD OF OBTAINING COMPOSITE SAMPLES. The reader is referred to Chapter VI for methods recommended for obtaining representative samples of all the various dairy prod- ucts. It must be kept constantly in mind that accuracy of final results is impossible unless the samples taken be representative of the entire batch. 132 Standardization oi' Dairy Products METHOD OF GETTING WEIGHTS OF THE PRODUCTS. The man who does the standardizing should be sure that the pounds of whole milk, likewise the pounds of cream and skim-milk used as well as the pounds of all other products involved are cor- rectly reported, and properly checked. If this part of the work is not properly done, large errors may be introduced in the work. In many plants it is impossible to weigh all the products accu- rately. In such cases the pounds should be obtained by multi- plying the volume by the specific gravity or by means of a grad- uated indicator upon the basis of definite weights of the product placed in the tank under the same temperature as obtain in prac- tice. METHOD OF TESTING RECOMMENDED. Where accurate results are desired, the Mojonnier Tester should be used for making both fat and total solids tests. Only approximate results can be obtained if other methods are used for making these determinations. METHOD OF CALCULATION TO USE. In subsequent chapters methods of calculation are given, cov- ering the entire range of important dairy products, under a wide variety of conditions. The reader is referred to these chapters for all details. For the sake of clarity, solutions are given by formula, by rule and by example, using simple arithmetic only. THE USE OF TABLES IN SHORTENING CALCULATIONS. Much time in making the calculations can be saved by using tables, the following of which are especially recommended : (1.) Table showing the percentage of S. N. F. and percentage of total solids corresponding to any given percentage of fat in cream. (2.) Table showing percentage of S. N. F. in various dairy products corresponding to any given percentage of fat. Tables of this kind can be prepared to cover all different dairy products. To prepare such tables, it is necessary to know the final composi- tion of the product desired. Several tables of this nature will be found in subsequent chapters, and the reader will find the proper explanation for their use in connection therewith, Composition of Cream 133 Table 22 gives the corresponding: percentage of fat, solids not fat and total solids in cream starting with a cream having a total solids content of 23.00 per cent and ending with a cream having a total solids content of 60 per cent. The values given were derived from the formula : F=: 1.102 X T. S. — 10.2 F ^^ the percentage of fat T. S. = the percentage of total solids. The formula is based upon the assumption that on the average there are 100 parts of water for 10.2 parts of milk solids not fat. An example taking an actual test of cream for both fat and total solids using the Mojonnier Tester will serve to illustrate how the above formula is derived. The sample tested 45.20 per cent total solids and 39.61 per cent fat. 100 — 45.20 = 54.80, per cent water in sample. 45.20 — 39.61 = 5.59, per cent solids not fat in sample. To find parts or units of solids not fat for 100 parts of water, we have the ratio : 54.80 : 100 = 5.59 : X X = 10.20, the parts of solids not fat contained in 100 parts of water in cream of the above test. In some cases the actual test as found by means of the Mojon- nier Tester may be either a little higher or a little lower than the values given in the table. Inasmuch as the total pounds of cream used in standardizing, as a rule are not large, an error as above mentioned would not appreciably afifect the final results. 134 Standardization oi^ Dairy Products TABLE 22. Per Cent S. N. F. and T. S. in Cream Corresponding to Any Given Percentage of Fat. Fat. S.N.F. T. S. Fat. S. N. F. T.S. Fat. S.N.F. T.S. 15.15 7.85 23.00 17.41 7.64 25.05 19.66 7.44 27.10 15.20 7.85 23.05 17.46 7.64 25.10 19.72 7.43 27.15 15.25 7.84 23.10 17.52 7.63 25.15 19.77 7.43 27.20 15.31 7.84 23.15 17.57 7.63 25.20 19.83 7.42 27.25 15.37 7.83 23.20 17.63 7.62 25.25 19.88 7.42 27.30 15.42 7.83 23.25 17.68 7.62 25.30 19.94 7.41 27.35 15.48 7.82 23.30 17.74 7.61 25.35 19.99 7.41 27.40 15.53 7.82 23.35 17.79 7.61 25.40 20.05 7.40 27.45 15.59 7.81 23.40 17.85 7.60 25.45 20.11 7.39 27.50 15.64 7.81 23.45 17.90 7.60 25.50 20.16 7.39 27.55 15.70 7.80 23.50 17.96 7.59 25.55 20.22 7.38 27.60 15.75 7.80 23.55 18.01 7.59 25.60 20.27 7.38 27.65 15.81 7.79 23.60 18.07 7.58 25.65 20.32 7.37 27.70 15.86 7.79 23.65 18.12 7.58 25.70 20.38 7.37 27.75 15.92 7.78 23.70 18.18 7.57 25.75 20.44 7.36 27.80 15.97 7.78 23.75 18.23 7.57 25.80 20.49 7.36 27.85 16.03 7.77 23.80 18.29 7.56 25.85 20.55 7.35 27.90 16.08 7.77 23.85 18.34 7.56 25.90 20.60 7.35 27.95 16.14 7.76 23.90 18.40 7.55 25.95 20.68 7.34 28.00 16.19 7.76 23.95 18.45 7.55 26.00 20.71 7.34 28.05 16.25 7.75 24.00 18.51 7.54 26.05 20.77 7.33 28.10 16.30 7.75 24.05 18.56 7.54 26.10 20.82 7.33 28.15 16.36 7.74 24.10 18.62 7.53 26.15 20.88 7.33 28.20 16.41 7.74 24.15 18.67 7.53 26.20 20.93 7.32 28.25 16.47 7.73 24.20 18.73 7.52 26.25 20.99 7.31 28.30 16.52 7.73 24.25 18.78 7.52 26.30 21.04 7.31 28.35 16.58 7.72 24.30 18.84 7.51 26.35 21.10 7.30 28.40 16.63 7.72 24.35 18.89 7.51 26.40 21.15 7.30 28.45 16.69 7.71 24.40 18.95 7.50 26.45 21.21 7.29 28.50 16.74 7.71 24.45 19.00 7.50 26.50 21.26 7.29 28.55 18.80 7.70 24.50 19.06 7.49 26.55 21.32 7.28 28.60 16.85 7.70 24.55 19.11 7.49 26.60 21.37 7.28 28.65 16.91 7.69 24.60 19.17 7.48 26.65 21.43 7.27 28.70 16.96 7.69 24.65 19.22 7.48 26.70 21.48 7.27 28.75 17.02 7.68 24.70 19.28 7.47 26.75 21.54 7.26 28.80 17.07 7.68 24.75 19.33 7.47 26.80 21.59 7.26 28.85 17.13 7.67 24.80 19.39 7.46 26.85 21.65 7.25 28.90 17.18 7.67 24.85 19.44 7.46 29.90 21.70 8.25 28.95 17.24 7.66 24.90 19.50 7.45 26.95 21.76 7.24 29.00 17.29 7.66 24.95 19.55 7.45 27.00 21.81 7.24 29.05 17.35 7.65 25.00 19.61 7.44 27.05 21.87 7.23 29.10 Composition of Crivam TABLE 22 (Continued). 135 Fat. S.N.F. T.S. Fat. S.N.F. T.S. Fat. S.N.F. T.S. 21.92 7.23 29.15 24.18 7.02 31.20 26.44 6.81 33.25 21.98 7.22 29.20 24.24 7.01 31.25 26.50 6.80 33.30 22.03 7.22 29.25 24.29 7.01 31.30 26.55 6.80 33.35 22.09 7.21 29.30 24.35 7.00 31.35 26.61 6.79 33.40 22.14 7.21 29.35 24.40 7.00 31.40 26.66 6.79 33.45 22.20 7.20 29.40 24.46 6.99 31.45 26.72 6.78 33.50 22.25 7.20 29.45 24.51 6.99 31.50 26.77 6.78 33.55 22.31 7.19 29.50 24.57 6.98 31.55 26.83 6.77 33.60 22.36 7.19 29.55 24.62 6.98 31.60 26.88 6.77 33.65 22.42 7.18 29.60 24.68 6.97 31.65 26.94 6.76 33.70 22.47 7.18 29.65 24.73 6.97 31.70 26.98 6.76 33.75 22.53 7.17 29.70 24.79 6.96 31.75 27.05 6.75 33.80 22.58 7.17 29.75 24.84 6.96 31.80 27.10 6.75 33.85 22.64 7.16 29.80 24.90 6.95 31.85 27.16 6.74 33.90 22.69 7.16 29.85 24.95 6.95 31.90 27.21 6.74 33.95 22.75 7.15 29.90 25.01 6.94 31.95 27.27 6.73 34.00 22.80 7.15 29.95 25.06 6.94 32.00 27.32 6.73 34.05 22.86 7.14 30.00 25.12 6.93 32.05 27.38 6.72 34.10 22.91 7.14 30.05 25.17 6.93 32.10 27.43 6.72 34.15 22.97 7.13 30.10 25.23 6.92 32.15 27.49 6.71 34.20 23.03 7.12 30.15 25.28 6.92 32.20 27.54 6.71 34.25 23.08 7.12 30.20 25.34 6.91 32.25 27.60 6.70 34.30 23.14 7.11 30.25 25.39 6.91 32.30 27.65 6.70 34.35 23.19 7.11 30.30 25.45 6.90 32.35 27.71 6.69 34.40 23.25 7.10 30.35 25.50 6.90 32.40 27.76 6.69 34.45 23.30 7.10 30.40 25.56 6.89 32.45 27.82 6.68 34.50 23.36 7.09 30.45 25.62 6.88 32.50 27.87 6.68 34.55 23.41 7.09 30.50 25.67 6.88 32.55 27.93 6.67 34.60 23.47 7.08 30.55 25.73 6.87 32.60 27.98 6.67 34.65 23.52 7.08 30.60 25.78 6.87 32.65 28.04 6.66 34.70 23.58 7.07 30.65 25.84 6.86 32.70 28.09 6.66 34.75 23.63 7.07 30.70 25.89 6.86 32.75 28.15 6.65 34.80 23.69 7.06 30.75 25.95 6.86 32.80 28.20 6.65 34.85 23.74 7.06 30.80 26.00 6.85 32.85 28.26 6.64 34.90 23.80 7.05 30.85 26.06 6.84 32.90 28.31 6.64 34.95 23.85 7.05 30.90 26.11 6.84 32.95 28.37 6.63 35.00 23.91 7.04 30.95 26.17 6.83 33.00 28.43 6.62 35.05 23.96 7.04 31.00 26.22 6.83 33.05 28.48 6.62 35.10 24.02 7.03 31.05 26.28 6.82 33.10 28.54 6.61 35.15 24.07 7.03 31.10 26.33 6.82 33.15 28.59 6.61 35.20 24.13 7.02 31.15 26.39 6.81 33.20 28.65 6.60 35.25 136 Standardization of Dairy Products TABLE 22 (Continued). Fat. S.N.F. T.S. Fat. S.N.F. T.S. Fat. S.N.F. T.S. 28.70 6.60 35.30 30.96 6.39 37.35 33.22 6.18 39.40 28.76 6.59 35.35 31.01 6.39 37.40 33.27 6.18 39.45 28.81 6.59 35.40 31.07 6.38 37.45 33.33 6.17 39.50 28.87 6.58 35.45 31.13 6.37 37.50 33.38 6.17 39.55 28.92 6.58 35.50 31.18 6.37 37.55 33.44 6.16 39.60 28.98 6.57 35.55 31.24 6.36 37.60 33.49 6.16 39.65 29.03 6.57 35.60 31.29 6.36 37.65 33.55 6.15 39.70 29.09 6.56 35.65 31.35 6.35 37.70 33.60 6.15 39.75 29.14 6.56 35.70 31.40 6.35 37.75 33.66 6.14 39.80 29.20 6.55 35.75 31.46 6.34 37.80 33.71 6.13 39.85 29.25 6.55 35.80 31.51 6.34 37.85 33.77 6.13 39.90 29.31 6.54 35.85 31.57 6.33 37.90 33.82 6.13 39.95 29.36 6.54 35.90 31.62 6.33 37.95 33.88 6.12 40.00 29.42 6.53 35.95 31.68 6.32 38.00 33.94 6.11 40.05 29.47 6.53 36.00 31.73 6.32 38.05 33.99 6.11 40.10 29.53 6.52 36.05 31.79 6.31 38.10 34.05 6.10 40.15 29.58 6.52 36.10 31.84 6.31 38.15 34.10 6.10 40.20 29.64 6.51 36.15 31.90 6.30 38.20 34.16 6.09 40.25 29.69 6.51 36.20 31.95 6.30 38.25 34.21 6.09 40.30 29.75 6.50 36.25 32.01 6.29 38.30 34.27 6.08 40.35 29.80 6.50 36.30 32.06 6.29 38.35 34.32 6.08 40.40 29.86 6.49 36.35 32.12 6.28 38.40 34.38 6.07 40.45 29.91 6.49 36.40 32.17 6.28 38.45 34.43 6.07 40.50 29.97 6.48 36.45 32.23 6.27 38.50 34.49 6.06 40.55 30.02 6.48 36.50 32.28 6.27 38.55 34.54 6.06 40.60 30.08 6.47 36.55 32.34 6.26 38.60 34.60 6.05 40.65 30.13 6.47 36.60 32.39 6.26 38.65 34.65 6.05 40.70 30.19 6.46 36.65 32.45 6.25 38.70 34.71 6.04 40.75 30.24 6.46 36.70 32.50 6.25 38.75 34.76 6.04 40.80 30.30 6.45 36.75 32.56 6.24 38.80 34.82 6.03 40.85 30.35 6.45 36.80 32.61 6.24 38.85 34.87 6.03 40.90 30.41 6.44 36.85 32.67 6.23 38.90 34.93 6.02 40.95 30.46 6.44 36.90 32.72 6.23 38.95 34.98 6.02 41.00 30.52 6.43 36.95 32.78 6.22 39.00 35.04 6.01 41.05 30.57 6.43 37.00 32.83 6.22 39.05 35.09 6 01 41.10 30.63 6.42 37.05 32.89 6.21 39.10 35.15 6.00 41.15 30.68 6.42 37.10 32.94 6.21 39.15 35.20 6.00 41.20 30.74 6.41 37.15 33.00 6.20 39.20 35.26 5.99 41.25 30.79 6.41 37.20 33.05 6.20 39.25 35.31 5.99 41.30 30,85 6.40 37.25 33.11 6.19 39.30 35.37 5.98 41.35 30.90 6.40 37.30 33.16 6.19 39.35 35.42 5.98 41.40 Composition of Cream TABLE 22 (Continued). 137 Fat. S.N.F. T.S. Fat. S.N.F. T.a. Fat. S.N.F. 5.55 T.S. 35.48 5.97 41.45 37.74 5.76 43.50 40.00 45.55 35.53 5.97 41.50 37.79 5.76 43.55 40.05 5.55 45.60 35.59 5.96 41.55 37.85 5.75 43.60 40.11 5.54 45.65 35.64 5.96 41.60 37.90 5.75 43.65 40.16 5.54 45.70 35.70 5.95 41.65 37.96 5.74 43.70 40.22 5.53 45.75 35.75 5.95 41.70 38.01 5.74 43.75 40.27 5.53 45.80 35.81 5.94 41.75 38.07 5.73 43.80 40.33 5.52 45.85 35.86 5.94 41.80 38.12 5.73 43.85 40.38 5.52 45.90 35.92 5.93 41.85 38.18 5.72 43.90 40.44 5.51 45.95 35.97 5.93 41.90 ■ 38.23 5.72 43.95 40.49 5.51 46.00 36.03 5.92 41.95 38.29 5.71 44.00 40.55 5.50 46.05 36.08 5.92 42.00 38.34 5 71 44.05 40.60 5.50 46.10 36.14 5.91 42.05 38.40 5.70 44.10 40.66 5.49 46.15 36.19 5.91 42.10 38.45 5.70 44.15 40.71 5.49 46.20 36.25 5.90 42.15 38.51 5.69 44.20 40.77 5.48 46.25 36.30 5.90 42.20 38.56 5.69 44.25 40.82 5.48 46.30 36.36 5.89 42.25 38.62 5.68 44.30 40.88 5.47 46.35 36.41 5.89 42.30 38.67 5 68 44.35 40.93 5.47 46.40 36.47 5.88 42.35 38.73 5.67 44.40 40.99 5.46 46.45 36.52 5.88 42.40 ■ 38.78 5.67 44.45 41.04 5.46 46.50 36.58 5.87 42.45 38.84 5.66 44.50 41.10 5.45 46.55 36.64 5.86 42.50 38.89 5.66 44.55 41.15 5.45 46.60 36.69 5.86 42.. 55 38.95 5.65 44.60 41.21 5.44 46.65 36.75 5.85 42.60 39.00 5.65 44.65 41.26 5.44 46.70 36.80 5.85 42.65 39.06 5.64 44.70 41. .32 5.43 46.75 36.86 5.84 42.70 39.11 5.64 44.75 41.37 5.43 46.80 36.91 5.84 42.75 39.17 5.63 44.80 41 .43 5.42 46.85 36.97 5.83 42.80 39.22 5.63 44.85 41.48 5.42 46.90 37.02 5.83 42.85 39.28 5.62 44.90 41. .54 5.41 46.95 37.08 5.82 42.90 39.33 5.62 44.95 41.59 5.41 47.00 37.13 5.82 42.95 39.39 5.61 45.00 41.65 5.40 47.05 37.19 5.81. 43.00 .39.45 5.60 45.05 41.70 5.40 47.10 37.24 5.81 43.05 39.50 5.60 45.10 41.76 5.39 47.15 37.30 5.80 43.10 39.56 5.59 45.15 41.81 5.39 47.20 37.35 5.80 43.15 39.61 5.59 45.20 41.87 5.38 47.25 37.41 5.79 43.20 39.67 5.58 45.25 41.92 5.38 47.30 37.46 5.79 43.25 39.72 5.58 45.30 41.98 5.37 47.35 37.52 5.78 43.30 39.78 5.57 45.35 42.03 5.37 47.40 37.57 5.78 43.35 39.83 5.57 45.40 42.09 5.36 47.45 37.63 5.77 43.40 39.89 5.56 45.45 42.15 5.35 47.50 37.68 5.77 43.45 39.94 5.56 45.50 42.20 5.35 47.55 138 Standardization of Dairy Produci's TABLE 22 (Continued). Fat. S.N.F. T.S. Fat. S.N.F. T.S. Fat. S.N.F. T.S. 42.26 5.34 47.60 44.51 5.14 49.65 46.77 4.93 51.70 42.31 5.34 47.65 44.57 5.13 49.70 46.83 4.92 51.75 42.37 5.33 47.70 44.62 5.13 49.75 46.88 4.92 51.80 42.42 5.33 47.75 44.68 5.12 49.80 46.94 4.91 51.85 42.48 5.32 47.80 44.73 5.12 49.85 46.99 4.91 51.90 42.53 5.32 47.85 44.79 5.11 49.90 47.05 4.90 51.95 42.59 5.31 47.90 44.84 5.11 49.95 47.10 4.90 52.00 42.64 5.31 47.95 44.90 5.10 50.00 47.16 4.89 52.05 42.70 5.30 48.00 44.96 5.09 50.05 47.21 4.89 52.10 42.75 5.30 48.05 45.01 5.09 50.10 47.27 4.88 52.15 42.81 5.29 48.10 45.07 5.08 50.15 47.32 4.88 52.20 42.86 5.29 48.15 45.12 5.08 50.20 47.38 4.87 52.25 42.92 5.28 48.20 45.18 5.07 50.25 47.43 4.87 52.30 42.97 5.28 45.25 45.23 5.07 50.30 47.49 4.86 52.35 43.03 5.27 48.30 45.29 5.06 50.35 47.54 4.86 52.40 43.08 5.27 48.35 45.34 5.06 50.40 47.60 4.85 52.45 43.14 5.26 48.40 45.40 5.05 50.45 47.66 4.84 52.50 43.19 5.26 48.45 45.45 5.05 50.50 47.71 4.84 52.55 43.25 5.25 46.50 45.51 5.04 50.55 47.77 4.83 52.60 43.30 5.25 48.55 45.56 5.04 50.60 ■ 47.82 4.83 52.65 43.36 5.24 48.60 45.62 5.03 50.65 47.88 4.82 52.70 43.41 5.24 48.65 45.67 5.03 50.70 47.93 4.82 52.75 43.47 5.23 48.70 45.73 5.02 50.75 47.99 4.81 52.80 43.52 5.23 48.75 45.78 5.02 50.80 48.04 4.81 52.85 43.58 5.22 48.80 45.84 5.01 50.85 48.10 4.80 52.90 43.63 5.22 48.85 45.89 5.01 50.90 48.15 4.80 52.95 43.69 5.21 48.90 45.95 5.00 50.95 48.21 4.79 53.00 43.74 5.21 48.95 46.00 5.00 51.00 48.26 4.79 53.05 43.80 5.20 49.00 46.06 4.99 51.05 48.32 4.78 53.10 43.85 5.20 49.05 46.11 4.99 51.10 48.37 4.78 53.15 43.91 5.19 49.10 46.17 4.98 51.15 48.43 4.77 53.20 43.96 5.19 49.15 46.22 4.98 51.20 48.48 4.77 53.25 44.02 5.18 49.20 46.28 4.97 51.25 48.54 4.76 53.30 44.07 5.18 49.25 46.33 4.97 51.30 48.59 4.76 53.35 44.13 5.17 49.30 46.39 4.96 51.35 48.65 4.75 53.40 44.18 5.17 49.35 46.44 4.96 51.40 48.70 4.75 53.45 44.24 5.16 49.40 46.50 4.95 51.45 48.76 4.74 53.50 44.29 5.16 49.45 46.55 4.95 51.50 48.81 4.74 53.55 44.35 5.15 49.50 46.61 4.94 51.55 48.87 4.73 53.60 44.40 5.15 49.55 46.66 4.94 51.60 48.92 4.73 53.65 44.46 5.14 49.60 46.72 4.93 51.65 48.98 4.72 53.70 Composition of Crkam TABLE 22 (Concluded) 139 Fat. S.N.F. T.S. Fat. S.N.F. T.S. Fat. S.N.F. T.S. 49.03 4.72 53.75 51.35 4.50 55.85 53.66 4.29 57.95 49.09 4.71 53.80 51.40 4.50 55.90 53.72 4.28 58.00 49.14 4.71 53.85 51.46 4.49 55.95 53.77 4.28 58.05 49.20 4.70 53.90 51.51 4.49 56.00 53.83 4.27 58.10 49.25 4.70 53.95 51.57 4.48 56.05 53.88 4.27 58.15 49.31 4.69 54.00 51.62 4.48 56.10 53.94 4.26 58.20 49.36 4.69 54.05 51.68 4.47 56.15 53.99 4.26 58.25 49.42 4.68 54.10 51.73 4.47 56.20 54.05 4.25 58.30 49.47 4.68 54.15 51.79 4.46 56.25 54.10 4.25 58.35 49.53 4.67 54.20 51.84 4.46 56.30 54.16 4.24 58.40 49.58 4.67 54.25 51.90 4.45 56.35 54.21 4.24 58.45 49.64 4.66 54.30 51.95 4.45 56.40 54.27 4.23 58.50 49.69 4.66 54.35 52.01 4.44 56.45 54.32 4.23 58.55 49.75 4.65 54.40 52.06 4.44 56.50 54.38 4.22 58.60 49.80 4.65 54.45 52.12 4.43 56.55 54.43 4.22 58.65 49.86 4.64 54.50 52.17 4.43 56.60 54.49 4.21 58.70 49.91 4.64 54.55 52.23 4.42 56.65 54.54 4.21 58.75 49.97 4.63 54.60 52.28 4.42 56.70 54.60 4.20 58.80 50.02 4.63 54.65 52.34 4.41 56.75 54.65 4.20 58.85 50.08 4.62 54.70 52.39 4.41 56.80 54.71 4.19 58.90 50.13 4.62 54.75 52.45 4.40 56.85 54.76 4.19 58.95 50.19 4.61 54.80 52.50 4.40 56.90 54.82 4.18 59.00 50.24 4.61 54.85 52.56 4.39 56.95 54.87 4.18 59.05 50.30 4.60 54.90 52.61 4.39 57.00 54.93 4.17 59.10 50.35 4.60 54.95 52.67 4.38 57.05 54.98 4.17 59.15 50.41 4.59 55.00 52.72 4.38 57.10 55.04 4.16 59.20 50.47 4.58 55.05 52.78 4.37 57.15 55.08 4.16 59.25 50.52 4.58 55.10 52.83 4.37 57.20 55.15" 4.15 59.30 50.58 4.57 55.15 52.89 4.36 57.25 55.20 4.15 59.35 50.63 4.57 55.20 52.94 4.36 57.30 55.26 4.14 59.40 50.69 4.56 55.25 53.00 4.35 57.35 55.31 4.14 59.45 50.74 4.56 55.30 53.05 4.35 57.40 55.37 4.13 59.50 50.80 4.55 55.35 53.11 4.35 57.45 55.42 4.13 59.55 50.85 4.55 55.40 53.17 4.33 57.50 55.48 4.12 59.60 50.91 4.54 55.45 53.22 4.33 57.55 55.53 4.12 ' 59.65 50.96 4.54 55.50 53.28 4.32 57.60 55.59 4.11 59.70 51.02 4.53 55.55 53.33 4.32 57.65 55.64 4.11 59.75 51.07 4.53 55.60 53.39 4.31 57.70 55.70 4.10 59.80 51.13 4.52 55.65 53.44 4.31 57.75 55.75 4.10 59.85 51.18 4.52 55.70 53.50 4.30 57.80 55.81 4.09 59.90 51.24 4.51 55.75 53.55 4.30 57.85 55.86 4.09 59.95 51.29 4.51 55.80 53.61 4.29 57.90 55.92 4.08 60.00 140 Standardization of Dairy Products ORDER OF OPERATIONS IN STANDARDIZING DAIRY PRODUCTS. The following order of operations is typical of that recom- mended in standardizing the majority of dairy products. The order as given will have to be departed from in some cases, but where possible to follow it can be the means of saving con- siderable time. Owing to the perishable nature of dairy prod- ucts it becomes necessary to study the various operations with the view of saving time where possible. (1.) Test as far in advance as possible all products that may be required when standardizing. Tests to include both fat and total solids where standardization might require both values to be known. (2.) About half an hour before the composite whole milk sample is ready, do everything necessary to begin making fat and total solids tests of the whole milk. Duplicate tests are recom- mended. If the operator is very careful in his work, a single de- termination may suffice. (3.) Keep the fat and total solids dishes in the respective ovens for five minutes under the proper heat and with the vac- uum on. (4.) Transfer the dishes from the ovens to the cooling desic- cators. Keep water circulating. Weigh the total solids dish with the cover on at the end of five minutes, and the fat dish alone at the end of seven minutes. Record weights and numbers upon the laboratory report. Replace dishes in the cooling desiccators. (5.) As soon as the composite whole milk sample reaches the laboratory, mix the same thoroughly by pouring back and forth at least six times into two vessels. (6.) Fill two gram pipette to the mark, and transfer the milk to the previously weighed dish and weigh the dish with the milk immediately. Or if preferred, the sample in the two gram pipette can be weighed from the weigh cross, or the weighing pipette. (7.) While one operator is weighing the sample as directed under (6) the second operator pipettes out 10 grams of whole milk into the fat extraction flask. Order of Operations 141 (8.) One operator now prepares the total solids sample for the total solids oven and the second operator the fat sample for the fat oven. Dishes are heated in ovens, cooled in cooling desic- cators and weighed in accordance with the directions. (9.) Calculate the percentage of fat and the percentage of total solids and transfer the result to the proper report blank. (10.) Calculate the average pounds of material to add, using the proper method of calculation. (11.) Calculate the average fat and total solids test after having added the required pounds of skim-milk or cream. (12.) Calculate the pounds of water required, if any is nec- essary. Make retest for fat and total solids after adding water. PRINCIPLES OF METHOD OF CALCULATION WHEN STANDARD- IZING FOR BOTH FAT AND SOLIDS NOT FAT. In standardizing for both fat and solids not fat, the exact per- centage of these two constituents desired in the finished product must be known. A definite ratio between the two then exists as soon as the composition has been established. This ratio forms the basis for the entire calculation, inasmuch as the problem then resolves itself into calculating the pounds of fat and solids not fat required in any desired mixture of dairy products so that these may be in the same ratio one to the other as in the case of the product desired. For example, evaporated milk, testing 8.00 per cent fat, 18.15 per cent solids not fat and 26.15 per cent total solids contains fat and solids not fat in the following ratio : 8.00 : 18.15 = 1 : X X = 2.2687, the pounds solids not fat that a standardized batch should contain for every pound of fat present. The ratio can be calculated in several ways, which will be ex- plained in subsequent chapters. CHAPTER X CALCULATIONS WHEN STANDARDIZING WHOLE MILK AND CREAM In standardizing milk for its fat content without regard to its percentage of solids not fat, the usual practice is to add cream when it is necessary to raise the percentage of fat ; and to add skim-milk when it is necessary to lower it. However, in the ease of certain whole milk products it is frequently necessary to stand- ardize upon the double basis of fat and solids not fat. In standardizing cream it is seldom necessary, or desirable, to standardize upon any basis other than the fat alone. This is owing to the greater value of the fat as compared with the solids not fat, and also to the fact that the solids not fat in cream are always lower than in whole milk, and the same vary greatly with the content of the fat in the cream. ■ In this chapter there are given methods of calculation covering the standardization of whole milk and cream upon the basis of the fat alone, and upon the double basis of the fat and solids not fat in the case of whole milk. A. HOW TO CALCULATE WHEN STANDARDIZING FOR FAT ALONE. The best method for standardizing for fat alone is the classic method devised by Prof. Pearson,^ or modifications of the Pearson method. This method is applicable to two different types of problems as follows: (1) When it is desired to make a product of definite fat test regardless of the resulting total weight; and (2) when it is desired to make a definite weight of product of a definite fat test. This method and its modification can be applied to milk, cream and several other dairy products. [142] Milk and Cream Mixtures 143 PROBLEM 1: HOW TO CALCULATE WHEN IT IS DESIRED TO MAKE A PRODUCT OF DEFINITE FAT TEST REGARDLESS OF THE RESULTING TOTAL WEIGHT. A rectangle is drawn and the desired percentage of fat is placed in the center of it. The percentage of fat in each of the materials to be mixed together is placed at the left hand corners. The smaller number on the left hand corner is then subtracted from the number in the center, and the difference is placed in the diagonally opposite right hand corner. The number in the center is subtracted from the larger number at the left hand cor- ner and the difference is placed in the diagonally opposite right hand corner. The two numbers at the right hand corners repre- sent the number of pounds of each material to bring together in order to make a mixture containing the fat percentage indicated in the center of the rectangle. The number on the right hand corner refers to the substance represented by the number on the left hand corner directly opposite. PROBLEM 1: HOW TO CALCULATE WHEN MIXING TOGETHER WHOLE MILK AND CREAM. Standardizing for Fat Only. Problem 1, Example 1: Hoav many pounds of 30 per cent cream must be mixed with 900 pounds of 3.2 per cent milk to make a mixture testing 3.6 per cent of fat? 26.4 The smaller figure at the left is subtracted from the figure at the center, leaving a difference of .4. The figure at the center is subtracted from the larger figure at the left, leaving a difference of 26.4. This shows that .4 of a pound of 30 per cent cream must be mixed with 26.4 pounds of 3.2 per cent milk to form a mixture 144 vStandardizing Mii,k and CrEam containing 3.6 per cent of fat. A calculation by simple proportion will give the total pounds of cream required as follows : .4 : 26.4 = X : 900 X = 13.64 or the pounds of cream required. Proof: 900 X .032= 28.80, lbs. fat in whole milk. 13.64X .30 = 4.09, lbs. fat in cream. 28.80+ 4.09 = 32.89, lbs. fat in mixture. 900+ 13.64 =913.64, lbs. in total mixture. 32.89-:-913.64 = 0.036, lbs. fat for one lb. of milk. 0.036X100 = 3.60, per cent fat desired. PROBLEM 1. EXAMPLE 2: HOW TO CALCULATE WHEN MIXING TOGETHER WHOLE MILK AND BUTTER TO MAKE CREAM. Problem 1, Example 2: How many pounds of butter testing 82.00 per cent fat must be mixed with 1,000 pounds of whole milk testing 3.75 per cent fat to make cream testing 18.00 per cent fat? 14.25 3.75 As in the case of Example 1, the pounds of butter required are found by a calculation in simple proportion as follows: 14.25 : 64 = X : 1000 X=:222.6, the pounds of butter to use. Proof: 1000 + 222.60=1222.6, or the pounds in total mixture. 1000 X .0375=37.50, lbs. fat in whole milk. 222.66 X .82=182.58, lbs. fat in butter. 37.50 + 182.58=220.08, lbs. fat in mixture. 220.08 H- 1222.60=0.18, lb. fat in one lb. cream. 0.18 X 100=18.0, per cent of fat desired. Definite Weights oe Products 145 PROBLEM 2: HOW TO CALCULATE WHEN IT IS DESIRED TO MAKE A DEFINITE WEIGHT OF PRODUCT OF A DEFINITE FAT TEST. This problem is solved most readily by a modification of the Pearson method devised by J. A. Cross. By the Pearson, method, the solution of this problem requires two subtractions, two addi- tions, two divisions and two multiplications. By the Cross modi- fication three subtractions, one division and one multiplication only are required. Solution Problem 2, based upon Rule 1 : Subtract the low test from the high tesi. Call remainder A. Subtract the low test from the standard desired. Call the differ- ence B. Divide B by A and multiply the result by the pounds of mixture desired. Call answer C, or the pounds of high testing material required. Subtract C from the total pounds required. The remainder will be the pounds of low testing material needed. Problem 2, Example 3 : How many pounds of milk containing 4.20 per cent of fat and skim-milk containing .1 per cent of fat must be mixed together to make 1000 pounds of milk testing 3.60 per cent fat? Solution Problem 2, Example 3, based upon Rule 1 : A'on~'i n X 1000=853.65, lbs. of 4.20 per cent milk required. 1000—853.65=146.34, lbs. of skim-milk required. Proof Problem 2, Example 3 : 853.65 X .042 = 35.85, pounds of fat in the whole milk. 146.34 X .001 = .15, pound of fat in the skim-milk. 35.85 + .15 = 36.00, pounds of fat in the mixture. 36.00 -^1000 — 0.036, lb. fat for one lb. milk. 0.036 X 100= 3.60, per cent of fat in the standardized milk. 146 Standardizing Milk and Cream THE CROSS DIAGRAM METHOD J. A. Cross has developed another excellent improvement of the above method, all based upon the principle of allegation. This method can be used whenever it is desired to mix together two products of different tests with the object of obtaining a definite weight of a third product of a definite test, or also an indefinite weight of a third product of a definite test. PRINCIPLE OF THE CROSS DIAGRAM METHOD. Let A and B be the weights of two ingredients to be mixed to produce a weight (A -|- B) of mixture. Let a and b be the per- centages in the two ingredients of some component common to both of them ; and let m be the percentage of the same component in the final mixture. Then the total weight of the component in the mixture is the sum of the weights of that compound in the two ingredients. Formulated algebraically this is aA 4- bB = m (A + B) The above equation may readily be transformed into the fol- lowing : A : B : : (m — b) : (a — m) Designating a, b and m as composition percentages we can state the above equation in what is called the Principle of Alle- gation : — "The weights of two ingredients needed to prepare a given mixture are inversely proportional to the differences between the composition percentages of these ingredients and that of the mix- ture itself." Dr. Pearson's method presents the above principle graphically. His method of subtraction insures giving the values of (m — b) and (a — m), and his diagram also automatically shows that these values are in inverse proportion to A : B. The mixture diagrams illustrated under Figs. 57 and 58 carry this principle a little farther by automatically getting the values of (m — b) and (a — m), and by taking advantage of a simple geometric principle these values are made to add always to 100 and can be considered as percentages. The Cross Diagram Method 147 APPLICATION OF THE CROSS DIAGRAM METHOD. This method can be applied to the standardization of either milk or cream. The results are accurate within one-half of one per cent or less. The diagram under Fig. 57, applies to cream, and that under Fig. 58 applies to skim-milk and whole milk. PROBLEM 2, EXAMPLE 3A: MATERIALS ON HAND, 30.00 PER CENT CREAM AND 10.00 PER CENT CREAM. WANTED 100 POUNDS OF 22.00 PER CENT CREAM. Solution Problem 2, Example 3A, based upon Cross Diagram Method : Lay a ruler across the diagram in such a way that it cuts 30 per cent on the left and 10 per cent on the right hand vertical scales. Then where the ruler cuts the diagonal scale marked 22 per cent, the pounds of 30 per cent cream can be read directly, namely, 60 pounds. The pounds of 10 per cent cream is then, of course, 40. In the same position, the ruler shows that 50 pounds of 30 per cent and 50 pounds of 10 per cent will produce 100 pounds of 20 per cent cream. Also that 40 pounds of 30 per cent and 60 pounds of 10 per cent will produce 100 pounds of 18 per cent cream.. The correct proportions of materials of any other percentages can also be found in the same way. Other problems may also be solved by this method. Example 3B. On hand 865 pounds of 26 per cent cream. How much 3.5 per cent milk is necessary to reduce the percentage to 22 per cent? Solution Example 3B, based upon Cross Diagram Method : Mixture diagram shows that 82 parts cream and 18 parts milk are necessary. Therefore, 865 -^ 865^:^189, pounds 3.5 per cent milk necessary. .82 Example 3C. On hand 625 pounds of 17.5 per cent cream. How much 40 per cent cream must be added to raise the percentage to 22 per cent? 148 Standardizing Milk and CrEam Solution Example 3C, based upon Cross Diagram Method: Mixture diagram shows that the proportion is 20 parts 40 per cent to 80 parts 17.5 per cent, therefore 625 — ^-r 625=157, pounds of 40 per cent cream necessary. .80 22 — 40 \^ v^ 2( -\ \; ^^33 \/o - 20—^ ' N^^ — 38 >^ \i- — 13 — V X :— 37 V'o Y° - 1-9 -T ^ \ \ '-—2>i> X^ Xt, ^^ — 17—^ \, xb N <«. uL ^35 X^' o X ''^ V \ — 16—^ X. \. \ :^34 15-^ \^r. V —33 Vo \. X ■e. — 14—: \ \ \ ^-s- ^32 \- >i, Xt >J <^„ — \2>—_ N v° v° :^3i \z-\ \ \ 1-30 II — \ X VoW ^23 10 ~ \ v^ X c V \ \ 1 &—_ V X %fo ^-26 x/° \° X 1 7-: \ \ 1-25 ^^ \ \ !<• -^ \ \ :^-2l \ \ z. 2—^ \ K° 1-20 1 — \ :^i3 x — V — 0^ \ t^i6 Pig-. 57. Cross Diagram Method for Standardizing- Cream. Hig-h Testing- Materials Vertical Big-ht Hand Column. Low Testing Materials Vertical Left Hand Column Test of Product Desired, also Percentag-e of Higrli Test- ing- Materials Kec[uired Upon Diagronal Scale. The; Cross Diagram Method 149 Either of the other scales (20 per cent or 18 per cent) will work in exactly the same way, or any desired scale can be sketched in. It would be very easilj^ possible to make a universal mixture diagram which would show the exact proportions of any two materials necessary to produce any desired percentage of an- other, and to arrange it in such a ^vay that the proportions would add to 100. Tig. 58. Cross Diagram Method for Standardizing- Milk. High Testing Materials Vertical Right Hand Column, low Testing Materials Vertical Left Hand Column. Test of Product Desired, also Percentage of High Test- ing Materials Required Upon Diagonal Scale. 150 Standardizing Milk and Cream ERF'S METHOD FOR SINGLE STANDARDIZATION. Another very excellent method for single standardization is that published by Prof. Erf.^ The method is based upon the mak- ing of suitable tables, and when these are once prepared the solu- tion desired is found by reference to the tables. Table 23 applies to the standardization of whole milk. TABLE 23. Quantity of skim-milk to be added to, or subtracted from, 100 pounds of milk to make milk of a desired percentage of fat. Per Cent Fat in Desired Percenta ge of Fat in Standardized Milk. Milk on Hand 3.25 3.50 3.75 4.0 4.25 4.50 -33.333 4.75 -36.842 5.0 3. - 7.693 -14.285 -20.000 -25.00 -29.412 -40.000 3.1 - 4.616 -11.428 -17.333 -22.50 -27.059 -31.111 -34.737 -38.000. 3.2 - 1.539 - 8.571 -14.666 -20.00 -24.706 -28.888 -32.632 -36.000 3.3 + 1.539 - 8.714 -12.000 -17.50 -22.353 -26.666 -30.527 -34.000 3.4 + 4.616 - 2.857 - 9.333 -15.00 -20.000 -44.444 -28.422 -32.000 3.5 + 7.693 - 0.000 - 6.666 -12.50 -17.647 -22.222 -26.317 -30.000 3.6 + 10.760 + 2.857 - 4.300 -10.00 -15.294 -20.000 -24.212 -28.000 3.7 + 13.837 + 5.714 - 1.333 - 7.50 -12.941 -17.777 -22.107 -26.000 3.8 + 16.914 + 8.571 + 1.333 - 5.00 -10.588 -15.555 -20.000 -24.000 3.9 + 19.991 + 11.428 + 4.000 - 2.50 - 8.235 -13.333 -17.897 -22.000 4.0 +23.068 + 14.285 + 6.666 - 0.00 - 5.882 -11.111 -15.792 -20.000 4.1 +26.145 + 17.142 + 9.333 + 2.50 - 2.429 - 8.888 -13.687 -18.000 4.2 +29.222 + 19.999 + 12.000 + 5.00 - 0.076 - 6.666 -11.582 -16.000 4.3 +32.299 +22.856 + 14.666 + 7.50 + 0.076 - 4.444 - 9.477 -14.000 4.4 +35.476 +25.713 + 17.333 + 10.00 + 2.429 - 2.222 - 7.372 -12.000 4.5 +38.453 +28.57 +20.000 + 12.50 + 5.882 - 0.000 - 5.267 -10.000 4.6 +41.530 +31.427 +22.666 + 15.00 + 8.235 + 2.222 - 3.162 - 8.000 4.7 +44.607 +34.284 +25.333 + 17.50 + 10.588 + 4.444 - 1.057 - 6.000 4.8 +47.684 +37.141 +28.000 +20.00 + 12.941 + 6.666 + 1.057 - 4.000 4.9 +50.761 +39.998 +30.666 +22.50 + 17.647 + 8.888 + 3.162 - 2.000 5.0 +53.828 +42.855 +33.333 +25.00 +20.000 + 11.111 + 5.267 - 0.000 To find the pounds of skim-milk to be added or removed, trace the vertical column of the desired per cent of fat to where the horizontal column presenting the percentage of fat in the milk on hand intersects ; the result will be tlie number of pounds of skim- milk to be added to or removed from 100 lbs. of milk, as indicated by a plus or minus sign before the figure. Key to Formulas 151 TABLE 24. Standardization of Fat Only in Cream. Percentage quantity of cream of a desired fat content made from cream of a certain fat content by diluting with milk containing 4 per cent of butter fat. Per Cent Fat in Desired Percentas;e of Fat in Standardized Cream Cream on Hand 17 20 22 25 27 30 18 92.857 19 86.666 20 81.250 100 21 76.4706 94.706 22 72.2222 88.8888 100 23 68.4222 84.2222 94.2125 24 65.0000 80.0000 90.0000 25 61.905 76.1905 85.7143 100 26 59.0909 72.7272 81.8181 95.4545 27 56.5217 69.5651 78.2608 91.3044 100 28 54.1666 66.6666 75.0000 87.5000 95.8333 29 52.0000 64.0000 72.0000 84.0000 92.0000 30 50.0000 61.5385 69.2308 80.3461 88.4615 100.00 If cream is to be standardized with 4 per cent milk, the result found by the intersecting columns represents the pounds per hun- dred, or the percentage of the quantity which is cream on hand containing the percentage of fat as indicated. Example : If cream containing 20 per cent of butterfat is de- sired and cream containing 26 per cent of fat is on hand, then 72.7 per cent of the quantity desired must be cream containing 26 per cent of fat and 27.3 per cent of the quantity must be 4 per cent milk. B. HOW TO CALCULATE WHEN STANDARDIZING WHOLE MILK OR CREAM FOR BOTH FAT AND SOLIDS NOT FAT. Key to Formulas for Standardizing- Whole Milk. The following key gives the information required for substi- tuting values for letters in the formulas found in this chapter : A = The percentage of fat desired in the standardized prod- uct. 152 Standardizing Mii.k and Cream D =: The pounds of skim-milk required for standardizing. F =: The percentage of fat in the whole milk. G = The percentage of fat in the cream, H = The percentage of fat in the butter. J = The percentage of S. N. F. in the cream. K == The percentage of fat in the skim-milk. L = The percentage of fat in the skim-milk powder. N = The percentage of S. N. F. in the skim-milk. M =The percentage of S. N. F. in the skim-milk powder. M'= The pounds of butter required or on hand. = The pounds of cream required for standardizing. 0'=: The pounds of skim-milk powder required. P = The pounds of whole milk in the batch. Q = The pounds of cream desired. R = The ratio of S. N. F. to fat in the desired product. S = The percentage of S. N. F. in the whole milk. S':= The average percentage of fat in the mixed batch. W= The pounds of water to be added. METHOD OF HANDLING PRODUCTS. Cream and skim-milk are the products used in the process of standardizing whole milk. They are usually secured by separat- ing some of the batch of whole milk on hand. It is best to remove a little more than the theoretical amount, since a small amount of fat remains in the skim-milk. The skim- milk is cooled and run into a separate tank, and after thoroughly mixing a sample is collected for the fat and total solids test. The cream is likewise promptly cooled, mixed and tested for fat. Where it is desired to make a homogenized product, the fresh milk, cream and skim-milk are to be properly homogenized before testing. All products should be carefully weighed, as otherwise inaccuracies will result. Where impracticable to weigh, convert gallons into pounds. When skim-milk is separated in excess of the amount required to standardize the whole milk, the excess may be standardized back to the composition of whole milk by adding the proper amount of cream. The aim in plant management should be to use each day all the by-products to the best advantage. When a product must be held over until the next day, there is usually Pounds of Milk Separated 153 less liability of loss if it is held in the form of cream. After learning the average fat and total solids test by means of the Mojonnier Tester, and the pounds of whole milk in the batch, the pounds necessary to separate to secure the cream, and the skim-milk for use in standardizing may be calculated as follows : PROBLEM 3: HOW TO CALCULATE POUNDS OF WHOLE MILK TO SEPARATE, TO OBTAIN CREAM AND SKIM-MILK NECESSARY TO STANDARDIZE BATCH. Solution Problem 3 by Formula 1, -^ IP = pounds of milk to remove to separate. Problem 3, Example 4: Lbs. of whole milk in batch = 10,000. Test of whole milk = 4.00 per cent fat, 8.60 per cent S. N. F. and 12.60 per cent T. S. Standardized product to test 3.25 per cent fat, 8,50 per cent S. N. F. and 11.75 per cent T. S. Solution of Example 4, Based Upon Formula 1 : 4.00 — 3.25 = .75, per cent of fat in excess. 10,000 X .0075 = 75, pounds of fat in excess. 75 -^ .04^=1875, pounds of milk to be skimmed. 10,000 — 1875 =: 8125, pounds milk containing enough fat to make 10,000 pounds of milk testing 3.25 per cent of fat. Separate 1875 lbs. of whole milk into cream and skim-milk to be used for standardizing purposes. PROBLEM 4: HOW TO CALCULATE THE AMOUNT OF SKIM- MILK TO ADD TO WHOLE MILK. "When it is necessary to add skim-milk the ratio between the per cent S. N. F. and fat in the whole milk must be more than the required ratio. Solution of Problem 4 by Rule 2 : (1.) Divide the percentage of fat in the skim-milk by the ratio between the S. N. F. and the fat in the product desired. Subtract the answer from the S. N. F. in the skim-milk. Call the remainder A, or the percentage of S. N. F. in the skim-milk avail- able for standardizing. 154 Standardizing Milk and Cream (2.) Divide the percentage of fat in the whole milk by the ratio between the S. N. F. and the fat in the product desired. Call the result B. Subtract from B the percentage of S, N, F. present in the whole milk. Multiply the remainder by the pounds of whole milk in the batch. Call result C. (3.) Divide C by A. The answer will be the number of pounds of skim-milk necessary to standardize the batch to the required ratio. (4.) Add together the pounds of whole and skim-milk in the mixed batch. Multiply the pounds of whole and skim-milk by their respective percentages of fat ; add together the two results, and divide the sum by the total pounds milk products in the mixed batch. Call the answer D, or the percentage of fat in the mixed batch. (5.) Subtract from D the percentage of fat desired. Mul- tiply the pounds in the mixed batch by the remainder and divide the answer by the percentage of fat desired. The result will be the pounds of water necessary to add. Solution Problem 4 by Formula 2: (1.) To calculate the pounds of skim-milk required. P ^ D KiH (2.) To calculate the average fat test of the mixed batch. DK + PF S' DP (3.) To calculate the pounds of water required. ^^,^ (S^ -A) (P + D ) Problem 4, Example 5: Products Pounds Per Cents Fat S. N. F. T. S. Whole Milk 10,000 3.77 .16 3.25 8.58 8.55 8.50 12.55 Skim-milk 8.71 Composition of product desired. . 11.75 Pounds of Milk Separated 155 Ratio S. N. F. to fat desired is 1 to .3824. Solution of Example 5, based upon Rule 2: (1.) To calculate the percentage of available S. N. F. in the skim-milk. .16 -^ .3824 = .42, per cent of S. N, F. required to equalize the fat in the skira-milk. 8.55 — .42 = 8.13, per cent of S. N. F, available for standard- izing. (2.) To calculate the pounds of S, N. F. short. ' 3.77 -:- .3824 r= 9.86, per cent of S. N. F. required. 9.86 — 8.58 = 1.28, per cent of S. N. F. short. 10,000 X .0128 = 128, pounds of S. N. F. short. (3.) To calculate the pounds of skim-milk required. 128-."- .0813 =: 1574, pounds of skira-milk required. (4.) To calculate the average fat test of the mixed batch. 10,000+1574=11574, total pounds of milk products in mixed batch. 10,000X. 0377=377, pounds of fat in whole milk. 1574X. 0016=2.52, pounds of fat in skim-milk. 377 + 2.52 = 379.52, total pounds of fat in mixed batch. 379.52 ~ 11574 = 3.28, per cent of fat in mixed batch. (5.) To calculate pounds of water required. 3.28 — 3.25 = .03, per cent of fat in excess. 11574 X .0003 = 3.47, pounds of fat in excess. 3.47 -:- .0325 = 107, pounds of water to add. Solution of Example 5, based upon Rule 2 : (1.) To calculate the pounds of skim-milk required. D = r/.0377\ ''''' L(^82ij - -^^^^ /.0016\ 1574 {2.) To calculate the average fat test of the mixed batch. )016) 4- (1000 10,000 -j- 1574 g, ^ (1574 X .0016) 4- (10000 X .0377) ^^^^ 156 Standardizing Milk and Cr^am (3.) To calculate the pounds of water required. (.0328 — .0325) X (10000 + 1574) W .0325 --=107 In the above example no factor of safety was allowed. Proof for Problem 4, Example 5: Products in Batch Pounds Fat Solids Not Fat After Standardizing Per Cent Pounds Per Cent Pounds Whole milk Skim-milk 10000 1574 107 3.77 .16 377.00 2.52 8.58 8.55 858.00 134.58 Water Total pounds and average test of mixed batch . . . 11681 3.25 379.52 8.50 992.58 PROBLEM 5: HOW TO CALCULATE THE POUNDS OF CREAM TO ADD TO WHOLE MILK. When it is necessary to add cream, the ratio between the per- centage of S. N. F. and fat in the whole milk must be less than the required ratio. Solution of Problem 5 by Rule 3 : (1.) Multiply the percentage of S. N. F. in the cream by the ratio between the S. N. F. and the fat in the product desired. Subtract the result from the percentage of fat in the cream. Call the remainder A, or the percentage of fat in the cream available for standardizing. (2.) Multiply the percentage of S. N. F. in the whole milk by the ratio between the S. N, F. and the fat in the product de- sired. Call the result B, or the percentage of fat required. Sub- tract from B the percentage of fat present in the whole milk. Multiply the remainder by the pounds of whole milk in the batch. Call the result C, or the pounds of fat short. (3.) Divide C by A. The answer will be the pounds of cream required to standardize the batch to the desired ratio. (4.) Add together the pounds of whole milk and cream in the batch. Multiply the pounds of whole milk and cream by their Calculating Whole Milk 157 respective percentages of fat; add together the two results and divide the sum by the total pounds of milk products in the mixed batch. Call the answer D or the percentage of fat in the mixed batch. (5.) Subtract from D the per cent of fat desired. Multiply the pounds in the mixed batch by the remainder and divide the answer by the per cent of fat desired. The result will be the pounds of water necessary to add. Solution of Problem 5 by Fornmla 3 : (1.) To calculate the pounds of cream required. RS — PF G— (JR) (2.) To calculate the average fat test of the mixed batch. OG + PF S> 04-P (3.) To calculate the pounds of water required. (S^-A) (0 + P) W = 1 Problem 5, Example 6 : Products Pounds Per Cfnts Fat S. N. F. T. S. Whole milk 10,000 3.05 22.05 3.25 8.60 6.50 8.50 11.65 Cream 28.55 Composition of product desired. . 11.75 Ratio of S. N. F. to fat desired is 1.0 to .3824. Solution of Example 6, based upon Rule 3: (1.) To calculate the percentage of available fat in the cream. 6.50 X .3824 = 2.49, per cent of fat required to equalize the S. N. F. in the cream. 22.05 — 2.49 — 19.56, per cent of fat in the cream available for standardizing. 158 Standardizing Milk and Cream (2.) To calculate the pounds of fat short. 8.60 X .3824 = 3.29, per cent fat required. 3.29 — 3.05 = .24, per cent of fat short. 10,000 X .0024 rrr 24, pounds of fat short. (3.) To calculate the pounds of cream required. 24-=-.1956=:123, pounds of cream required. (4.) To calculate the averag^e fat test of the mixed batch. 10,000 X .0305 = 305, pounds of fat in the whole milk. 123 X .2205 = 27, pounds of fat in the cream. 305 -f- 27 = 332, pounds of fat in the mixed batch. 10,000 + 123 = 10123, pounds of milk products in mixed batch. 332 ~ 10123 = 3.28, per cent of fat in mixed batch. (5.) To calculate the pounds of water required. 3.28 — 3.25 = .03, per cent of fat in excess. 10123 X .0003 = 3.03, pounds of fat in excess. 3.03 ~ .0325 = 93, pounds of water to add. Solution of Example 6, based upon Formula 3 : (1.) To calculate the pounds of cream required. [ (.3824 X .0860) — (10,000 X .0305) ] O = •- -^ — = 123 .2205— (.0650 X .3824) (2.) To calculate the average fat test of the mixed batch. g _ (123 X .2205) 4- (10,000 X .0305 ) __ ^ ^g ~ 123 + 10,000 (3.) To calculate the pounds of water required. ^ ^ (.0328— .0325) X (10,000+123) ^ ^^ .0325 In the above example no factor of safety is allowed. Use of Butter 159 Proof for Example 6 : Products in Batch Pounds Fat Solids Not Fat After Standardizing Per Cent Pounds Per Cent Pounds Whole milk Cream 10000 123 93 3.05 22.05 305 27 8.60 6.50 860. 8 Water Total pounds and average test of mixed batch . . . 10216 3.25 332 8.50 868. PROBLEM 6: HOW TO CALCULATE WHEN MIXING BUTTER AND SKIM-MILK POWDER TO MAKE WHOLE MILK OR CREAM. Two variations of this problem are encountered in plant prac- tice. (a) When the two products are mixed together with the view of obtaining a product of definite fat test regardless of the resulting total weight, and (b) when it is desired to make a defi- nite weight of product of a definite fat test. Examples covering the two kinds of problems will be given. The same method of calculation under the above two variations can be followed when it is desired to make either whole milk or cream. Solution of these problems by means of formula only are given herewith. Solution of Problem 6, Variation A based upon Formula 4: (1.) To calculate the pounds of skim-milk powder required. 0^ = QJ M (2.) (3.) To calculate the pounds of butter required. QA — O^L M^ H To calculate the pounds of water required. W=:Q— (M^ + O^) Problem 6, Variation A, Example 7: Wanted to make 1,000 pounds of cream testing 18.00 per cent of fat and 7.59 per cent of S. N. F. when using butter testing 160 Standardizing Milk and CrEaM 82.00 per cent of fat and skim-milk powder testing 1.00 per cent of fat and 94.00 per cent of S. N. F. Solution of Example 7, based upon Formula 4: (1.) To calculate the pounds of skim-milk powder required. ^.^ 1000 X. 0759^3,, .94 (2.) To calculate the pounds of butter required. Ml ^ (1000 X .18) - (80.7 X .01) ^ 218 5 .82 (3.) To calculate the pounds of water required. W = 1000 — (218.5 + 80.7) = 700.8 In the above example no factor of safety was allowed. The small amount of S. N. F. in the butter was disregarded. Proof of Problem 6, Example 7 : Products in Batch Pounds Fat Solids Not Fat After Standardizing Per Cent Pounds Per Cent Pounds Skim-milk powder . . Butter 80.7 218.5 700.8 1.00 82.00 .8 179.2 94.00 75.9 Water Total pounds and average test of mixed batch . . . 1000.0 18.00 180. 7.59 75.9 Solution of Problem 6, Variation B, based upon Formula 5: (1.) To calculate the pounds of whole milk possible to make. ^ M^ H (2.) To calculate the pounds of skim-milk powder required. PF 0V= M (3.) To calculate the pounds of water required. W=rP— (M^ + O^) Use of Skim-I\Iii.k Powder 161 Problem 6, Variation B, Example 8: Wanted to make as much whole milk as possible testing 3.75 per cent of fat, and 8.50 per cent of S. N. F. from 50 pounds of butter testing 82.00 per cent of fat, and skim-milk powder testing 1.00 per cent of fat and 94.00 per cent of S. N. F. Solution of Example 8, based upon Formula 5 : (1.) To calculate the pounds of whole milk possible to make. 50 X .82 P=: .0375 1093 (2. (3.: To calculate the pounds of skim-milk powder required. 1093 X .085 0^ = .94 98.8 To calculate the pounds of water required. W = 1093 — (50 + 98.8) = 944.2 In the above example the fat in the skim-milk powder and the S. N. F. in the butter were disregarded, as the amount of these constituents is too small to affect appreciably the results. Proof of Problem 6, Example 8 : Products in Batch Pounds Fat Solids Not Fat After Standardizing Per Cent Pounds Per Cent Pounds Skim-milk Powder. . Butter 98.8 50.0 944.2 1.00 82.00 Disregard 'd 41.0 94.0 1.00 92.9 Disregard'd Water Total pounds and average test of mixed batch . . . 1093.0 3.75 41.0 8.50 92.9 iPearson, R. A., Cornell Farmer.s Reading Course, Bui. 22, 1904. -Erf, O.scar, 111. Sta. Bui. No. 75. CHAPTER XI STANDARDIZING EVAPORATED MILK The principle underlying the entire practice of standardizing evaporated milk is based upon mixing together milk and the products obtained from milk in the proper proportions to make a product that contains the fat and the S. N. F. in the same ratio that they are to have in the standard product which it is desired to manufacture. These ratios can be obtained by referring to Table 25, page 165. They are derived by dividing the percentage of one constituent into the percentage of another constituent of the standard product. For example, standard domestic evapo- rated milk which tests 8.00 per cent fat, 18.15 per cent of S. N. F. and 26.15 per cent of T. S. gives a ratio between the S. N. F. and fat of 18.15 to 8.0, or 1 to .4407. Evaporated milk may also be standardized upon the basis of the fat only, or of the S. N. F. only. In such cases the unstandard- ized constituent will be, in the majority of cases, in excess of the standard requirements. Two general methods of standardizing evaporated milk are possible, namely before condensing and after condensing. In standardizing before condensing, the fat and the S. N. F. are placed in the proper proportion one to the other in the initial product, so that, after condensing, the product obtained can be either of exactly the standard required, or if overcondensed, it can be diluted back to the proper standard with water only. This chapter contains methods with examples that accompany the same, covering every known condition that may be encountered in plant practice, where evaporated milk is standardized both for fat and S. N. F. both before and after condensing. It is frequently impossible to standardize the initial products before condensing. This is particularly true when the multibatch system is used, as in that case there is scarcely time to make the required tests upon the fresh milk. However, this usually can [ 162] Steps in Standardizing 163 be so arranged by careful planning, and when possible the initial product should be standardized, as in that case all that is neces- sary is to add sufficient water after condensing to bring the evapo- rated product back to the desired standard. Where the condensed product is standardized, this can be ac- complished in several ways. In such cases, it is best for the prod- uct to come from the pan overcondensed, rather than undercon- densed, as it is possible to add more accurately the materials re- quired for standardizing when the batch is overcondensed rather than when the opposite is the case. Standardizing after condens- ing can be accomplished by one or more of the following methods : (1.) By the addition of water alone. This is the simplest standardization of all. (2.) By the addition of homogenized, pasteurized cream alone. (3.) By the addition of homogenized, condensed skim-milk. (If very low in fat, the homogenization can be omitted.) (4.) By the addition of water and homogenized, pasteurized cream. (5.) By the addition of water and homogenized, condensed skim-milk. (6.) By the addition of water, homogenized cream and homog- enized condensed whole milk. SUCCESSIVE STEPS IN STANDARDIZING EVAPORATED MILK REFORE CONDENSING The steps involved in standardizing evaporated milk are as follows : (1.) Obtaining a representative composite sample of the en- tire lot of whole milk which goes to make up the batch ; likewise of the skim-milk, cream, butter or other products which might be used in standardizing. (2.) Testing of all of the above products involved, for both fat and S. N. F. or T. S. by means of the Mojonnier Tester. In the case of the S. N. F. in cream, it usually suffices to obtain the S. N. F. from Table 22. In the case of unsalted butter, the amount of S. N. F. is so small as to be disregarded. (3.) Calculating the weight of each product to be used, by uiethods which follow, in order to make the fat and the S. N, F, 164 Standardizing Evaporatr;!) Milk in the initial product of the same ratio as these are to occur in the finished product. (4.) When the initial product has been standardized so that the fat and the S. N. F. are in the required ratio, the same is to be condensed down to the desired specific gravity to yield a fin- ished product of the test required. In practice it is well to con- dense the batch to a little higher concentration than desired, as it then becomes possible to bring it back to the desired point by the mere addition of water. If the concentration of the batch should be less than the required concentration it becomes necessary either to recondense part of the batch or condense another batch to add to it, which makes it a very much more difficult and involved problem than when it is necessary to add water only. Or if the plant should have concentrated pasteurized and homogenized cream, or condensed, homogenized whole milk available, these might be added, as the case might require. When the final prod- uct obtained from the pan contains an excess of fat over the S. N, F. the error may be corrected by adding condensed skim- milk if this is possible or practicable. Likewise if it contains an excess of S. N. F. over fat the error can be corrected by adding concentrated pasteurized and homogenized cream if this is avail- able. METHOD OF COLLECTING COMPOSITE MILK SAMPLES. No fixed method of sampling is recommended that can be ap- plied to meet all the varying conditions of different plants. This important matter will need careful study at each plant, in order to determine the procedure that will give the most accurate sam- ples. The reader is referred to Chapter VI for complete informa- tion upon this point. METHOD OF TESTING Use the Mojonnier Tester for making all fat and T, S. determin- ations, upon all products used in standardizing. The skim-milk and cream should be tested before the composite sample of the whole milk reaches the laboratory. The S. N. F. in the cream can be ascertained from Table 22, as the total amount of the same is usually small. As it is necessary to complete the fat and T. S. tests of the whole milk while the last forewarmer is being heated and drawn into the pan, these tests should be made as rapidly as Evaporated Milk Constants 165 possible. A short time before the sample is ready the tempera- ture of the hot plates and ovens should be regulated ; a fat and T. S. dish cooled and weighed ; clean glassware and a weigh cross prepared for use and everything put into readiness for making the test. By systematizing the successive steps, the time for com- pleting the fat and T. S. tests, including the total time for making the calculations, should not exceed twenty-five or thirty minutes, counting from the time the sample reaches the laboratory. Under some conditions it may be desirable to give the operator a helper while making the tests, as this would greatly expedite the opera- tions. CONSTANTS FOR EVAPORATED MILK The following table gives the constants for evaporated milk, both domestic and export. This is based upon standards now in force in this country and in Canada, and upon the standards called for in the European requirements. Domestic evaporated milk is given upon the double basis of 7.80 per cent of fat and 25.50 per cent of T. S. and 8.00 per cent of fat and 26.15 per cent of T, S. TABLE 25. Constants for Evaporated Milk. Export Domestic Domestic Constants Evaporated Evaporated Evaporated Milk Milk (A) Milk (B) Per cent fat 9.25 16.75 26.00 2.811 7.80 17.70 25.50 3.2692 8 00 Per cent S. N. F 18 15 Per cent total solids 26 15 Ratio per cent fat to per cent total solids. . . 3.2687 Ratio per cent fat to per cent S. N. F 1.811 2.2692 2.2687 Ratio per cent S. N. F. to per cent fat .... .5522 .4407 .4408 Ratio per cent S. N. F. to per cent total solids 1 . 5522 1 . 4407 1.4408 Ratio per cent total solids to per cent fat . . .3558 .3059 .3059 Net weight per can, ozs. Baby size 6.0 6.0 6.00 Net weight per can, ozs. Family size 12.0 12.0 12.00 Net weight per can, ozs. Tall size 16.0 16.0 16.00 Net weight per can, ozs. Hotel size 32.0 32.0 32.00 Net weight per can, ozs. Gallon size 136.0 136.0 136.00 Net weight per case, pounds. Baby size . . . 27.0 27.0 27.00 Net weight per case, pounds. Family size. . 36,0 36.0 36.00 Net weight per case, pounds. Tall size .... 48.0 48.0 48.00 Net weight per case, pounds. Hotel size. . . 48.0 48.0 48.00 Net weight per case, pounds. Gallon size. . 51.0 51.0 51.00 166 . Standardizing EvAPORATJiD Milk METHOD OF GETTING WEIGHTS. The one who does the standardizing should be sure that the pounds of whole milk, and likewise the pounds of cream or skim- milk used are correctly reported and properly checked. ORDER OF OPERATIONS IN STANDARDIZING EVAPORATED MILK BEFORE CONDENSING, USING MOJONNIER TESTER. (1.) Test, as far in advance as possible, the cream sample for fat. Obtain the S. N. F. test of the cream from Table 22, or, if necessary, test the skim-milk or the bulk condensed milk, for both fat and T. S. (2.) About half an hour before the composite whole milk sam- ple is ready, do everything necessary to begin making fat and T. S. tests of the whole milk. It is recommended that the tests be made in duplicate. If the operator is very careful in his work, a single determination may suffice. (3.) Keep the fat and the T. S. dishes in the respective ovens for five minutes, under proper heat, and with the vacuum on. (4.) Transfer dishes from the ovens to cooling desiccators. Keep water circulating through the cooling desiccators. Weigh the T. S. dish with the cover on at the end of five minutes, and the fat dish alone, at the end of seven minutes. Record the weights and numbers upon the laboratory report. Fig. 59. Replace dishes in the cooling desiccators. (5.) As soon as the composite wliole milk sample reaches the laboratory, mix the same thoroughly by pouring back and forth at least six times using two vessels. (6.) Fill a two gram pipette to the mark, and transfer the milk to the previously weighed dish, and immediately weigh the dish with the milk. Or, if preferred, the sample in the two gram pipette can be weighed from the weigh cross. (7.) While one operator is weighing the sample as under (6) the second operator pipettes out 10 grams into the fat extraction flask. (8.) One operator now prepares the T. S. sample for the T. S. oven and the second operator the fat sample for the fat oven. Ordkr Of* Operations 167 Dishes are heated in ovens ; cooled in oooling desiccators and weighed in accordance with directions. (9.) Calculate the percentage of fat, and the percentage of T, S. and transfer the results to the evaporated milk report blank. (10.) Calculate the pounds of material to add, using the method that may apply, selecting the proper one, beginning with Rule 4, and ending with Rule 15. (11.) Test the finished product for fat and T. S. and enter the results upon the evaporated milk report, Fig. 60. (12.) Divide the percentage of fat by the percentage of T. S. to get the ratio of T. S. to fat in the finished product. (13.) If the condensation is not otherwise obtained, divide the percentage of T. S. in the finished product by the percentage of T. S. in the initial product. (14.) Divide the total weight of raw products used by the condensation to obtain the pounds in the batch after condensing. , (15.) Add water, if necessary, using either Rule 10 or 11, Make a retest for fat and T. S. after adding water. (16.) Calculate the weight of milk from the cans filled, and figure loss in handling due to overfilling. ORDER AND OPERATIONS IN STANDARDIZING EVAPORATED MILK AFTER CONDENSING, USING THE MOJONNIER TESTER. (1.) Test, as far in advance as possible, the cream sample for fat. Obtain the S. N. F. test of the cream from Table 22, or, if necessary, test the condensed skim-milk or the condensed whole milk for both fat and T. S. (2.) About half an hour before the condensed batch is all completed, do everything necessary to begin making the fat and the T. S. tests. (3.) Keep the fat and the T. S. dishes in the respective ovens for five minutes, under proper heat, and with tlie vacuum on. (4.) Transfer the dishes from the ovens to the cooling desic- cators. Keep the water circulating. Weigh the T. S. dish with cover at the end of five minutes, and the fat dish alone at the end of seven minutes. Record the weights and numbers upon the 168 Standardizing Evaporatkd Milk laboratory report, Fig.. 59. Replace the dishes in the cooling desiccators. (5.) Mix the sample from the condensed batch very thor- oughly. FOR EVAPORATED AND CONDENSED MILK PLANTS Laboratory Report Pf.ANT Te BA DATE TCH No. TK8T CO«roS,,E OISB DISH PAT PIPETTES PIPETTES MILI i FAT ,.;:r:;u DISH SOUDS PIPETTES PIPETTES MIU SOLIDS ..„,*vjl,';jd.„ ""JT ""■<„;;■* j:.Er_ mUi.ik miU, '•';■-;% •tsSriiiir .'.u. I:St"™u'" IfcONo'ENS^J MOJONNIBR BROB. CO. Pig-. 59. Evaporated Milk Iiaboratory Report. (6.) Fill the one gram pipette to the mark, and transfer the milk to the previously weighed dish, and immediately weigh the dish with milk. Or, if preferred, the sample in the one gram pipette can be weighed from the weigh cross. Fill the five grams pipette to the mark, and by means of the weighing cross, weigh about five grams into the fat extraction flask. (7.) One operator now prepares the T. S. sample for the T. S. oven and the second operator the fat sample for the fat oven. Dishes are heated in ovens, cooled in cooling desiccators, and weighed in accordance with directions. (8.) Calculate the percentage of fat and the percentage of T. S. and transfer results to evaporated milk report, Fig. 60. (9.) Calculate the pounds of material necessary to add, se- lecting and using the rule that may apply. (10.) Mix the batch very thoroughly, after adding the ma- terial for standardizing. Blanks for Recording Data 169 Make a retest for fat and T. S. (11.) Divide the percentage of fat by the percentage of T. S. to get the ratio between the T. S. and the fat in the finished product. (12.) Complete all possible or necessary calculations upon the evaporated milk report, Fig. 60. BLANK FOR RECORDING STANDARDIZING DATA. It is important to use proper blank reports for recording all data in connection with the standardization of evaporated milk. A specially designed blank report is illustrated under Fig. 60. The blank is designed so that the uecessary facts covering an en- tire day's milk can be ascertained at a glance. EVAPORATED MILK REPORT Plant Bitch^o^ WK K£.SG ■•■■^ '3t.- -■■s= ^.-s. .S'Ji "i.ir "■■-"l-M: 1 rr- UMIUTOIIV Tt«T« "°~™"»<"'"° uw.«»»cn nn»ui«>i«rT CPTAinO ,f. •JW ar ,•. • ri .-,-. riui « >-.— _ sa=z. ._..-_ , — — , ""^ Pt« ROOM HI "^"^ WO CAM ironjD ^ " ■-■■>~— -J!l!l — '— |— '— |— ■— . 1 , 1 V uuu. T.l>..n.«te»iM T«.l..-.r— !«-«-•- caasftK~ ■~-'' Tig. 60. Blank Report for Evaporated Milk. 170 Standardizing EvAroRATED Milk HOW TO GET THE WEIGHT OF THE FINISHED BATCH OF EVAPORATED MILK. Ascertain the weight of fresh milk in the batch, and the weight of the finished product. The latter can be obtained in several ways, as follows: (A.) By weighing the entire batch in a drop tank near the pan. This is the most exact method of all. (B.) By means of a graduated brass bar or rod at the storage tank. This method is open to many variations, particularly if the tank surface is extensive. Variations in the concentration will also obviously affect the weight of any given volume, and may therefore cause considerable variation in the weight. The bar should be graduated by weighing definite successive portions of milk into the tank, and marking upon the bar the number of pounds corresponding to that in the tank at the given level. (C.) From the condensation. This method involves collect- ing an accurate com.posite sample of the raw milk that goes to make up the batch, and testing the same for T. S. If cream or skim-milk are added for standardizing, the T. S. test of the same should be ascertained, and the average T. S. test of the entire batch should be calculated. In turn when the finished product comes from the pan, this is to be tested for T. S., and the weight of condensed product obtained as indicated by the following example : Lbs. of fresh milk in the batch =6800 Lbs. of cream used in standardizing = 40 Lbs. total of all raw products =6840 T. S. test of the fresh milk = 12.01% T. S. test of the cream =49.28% Average T. S. test of the mixed milk and cream = 12.23% T. S. test of the finished product = 26.50% 26.50-^12.23 = 2.167, or the condensation. 6840—2.167 = 3156, the lbs. of evaporated milk which the batch contains. By means of the Green Gauge, which automatically indicates the weight of milk in tanks. Green Gauge 171 The Green Gauge may be attached to any tank used for hold- ing fresh milk, condensed milk or any other liquid product. The mercury column in the gauge rises and falls as the milk in the tank rises and falls. The scale back of the mercury col- umn is calibrated to fit the particular tank to which it is attached so that when the mercury column stops opposite a number or graduation it indicates accurately the number of pounds of milk in the tank. The calibrating is usually done by dumping into the tank carefully weighed quantities of water and marking the lieight to which the mercury column rises. In this way an ac- curate calibration is obtained. The Green Gauge operates on the hydrostatic mercuric princi- ple. The air trap is connected to the tank outlet by 1" Sanitary Tubing. When filling tank the pet cock at bottom of air trap is opened until a few drops of milk flow out. The pet cock is then closed sealing a pocket of air in the air trap. The air trap is connected to the mercury gauge by a 1/8" copper tube. The weight of the milk in the tank is exerted on the air in the air trap and in turn on the mercury column in the gauge on the wall. This Green Gauge is a very convenient appliance for use in any liquid, as it practically places the tank to which it is attached on scales. Fig-. 61. Green Gaugre. HOW TO CALCULATE THE POINT AT WHICH TO STRIKE THE BATCH IN THE PAN. The striking point at the vacuum pan requires very careful watching, in order that the product from the pan may be as near the standard desired as possible. Evaporated milk of a given composition and temperature has a definite specific gravity. As 172 Standardizing Evaporated Mii,k a starting point it is necessary to know the specific gravity under certain temperature conditions of the product which it is desired to manufacture. The two following tables give the specific gravity of evapo- rated milk of the two compositions mentioned above at different temperatures, and expressed in different specific gravity scales. TABLE 26. Specific gravity of evaporated milk testing 7.80 per cent fat, and 25.50 per cent total solids compared with water at 60° F. Samples furnished by Na- tional Dairy Co Specific gravity determinations made by J. A. Cross and H. J. Liedel. Specific Gravity Tempera- ture °F. Specific Gravity Tempera- ture °F. Specific Gravity Degrees Baume Degrees Twaddell Degrees Specific Gravity Degrees Baume Degrees Twaddell Degrees 40 60 80 100 1.0702 1.0662 1 . 0625 1.0572 9.51 9.00 8.52 7.83 14.04 13.24 12.50 11.44 110 120 130 140 1.0546 1.0518 1 . 0490 1 0457 7.51 7.14 6.78 6.35 10.92 10.36 9.80 9 14 TABLE 27. Specific gravity of evaporated milk testing 8.00 per cent fat, and 26.15 per cent total solids; compared with water at 60" F. Samples furnished by National Dairy Co. Specific gravity determinations made by J. A. Cross and H. J. Liedel. Specific Gravity Tempera- ture ° F. Specific Gravity Tempera- ture °F. Specific Gravity Degrees Baume Degrees Twaddell Degrees Specific Gravity Degrees Baume Degrees Twaddell Degrees 40 60 80 100 1.0718 1 . 0679 1 . 0638 1.0588 9.71 9.22 8.70 8.05 14.36 13.58 12.76 11.76 110 120 130 140 1.0559 1 . 0533 1.0505 1.0472 7.67 7.35 6.97 6.53 11.18 10.66 10.10 9.44 Specific Gravity 173 The specific gravity at temperatures between the extremes given in the above tables, and at temperatures not given in the tables can be readily ascertained by referring to the graph included in this chapter, and which relates to the specific gravity of evapo- rated milk at various temperatures and of different compositions, but of a constant ratio between the fat and the total solids. THE RELATION BETWEEN THE TEMPERATURE AND SPECIFIC GRAVITY IN EVAPORATED MILK. In the case of evaporated milk, testing either 7.8* per cent fat and 25.50 per cent T. S., or 8.00 per cent fat and 26.15 per cent T. S., the relation between temperature and specific gravity is nearly alike. This is indicated in Table 28. TABLE 28. Unit Relation of Temperature to Specific Gravity in Evapoiated Milk. Decrease in Degree F. Specific Gravity for Each Increase in Temperature Temperature Range Specific Gravity Baume Twaddell 40° to 80° F 80° to 110° F 110° to 140° F .00020 . 00026 .00029 .025 .034 .039 .040 .053 .058 Important use of the above relation can be made when striking the pan. If the milk should have a temperature either higher or lower than the standard desired, at the time of making the specific gravity test, the reading can be reduced to the standard desired by a simple calculation. Example A: Baume reading at 135° F. is 6.57. What is the Baume reading at 130° F.? 135 — 130—5, degrees F. over the standard desired. .039X5=.195, degrees Baume to be added to reading made at 135° F. 6.57+.195=6.77, the Baume reading reduced to 130° F. Example B : Baume reading at 120° F. is 7.14. What is the Baume reading at 130° F.? 174 Standardizing Evaporated Milk 130 — 120^10, degrees ¥. under the standard desired. .039X10=. 39, degrees Baume to be subtracted from reading made at 120° F. RELATION BETWEEN SPECIFIC GRAVITY AND COMPOSITION IN EVAPORATED MILK. When the hold-over system is used in the manufacture of evapo- rated milk, it is most desirable to make a preliminary test for fat or T. S., usually the test for one constituent being sufficient. This test should be timed so that the result is available before the milk for the last pan batch is all out of the hot wells. It is then pos- sible to change the striking point upon the last pan batch so that the test of the milk in the hold-over batch will be much closer to the desired standard than is usually possible where this practice is not followed. The great advantage is the fact that the water to be added can be reduced to a minimum. The relation between the composition and the specific gravity of evaporated milk in which the fat and the S. N. F. are in the ratio of 8.00 to 18.15, is indicated in Table 29. From the following table it is ascertained that a difference of .10^ Baume is equal to about .30 per cent of total solids in the case of evaporated milk of the composition indicated. Upon the specific gravity scale each .01 degree is equal to about .36 per cent total solids, and upon the Twaddell scale each .10 degrees is equal to about .18 per cent total solids. This information is of large practical value in fixing the striking point of the last pan batch used to make up a hold-over batch. Example: The fresh milk that makes up a hold-over batch totals 60,000 pounds. This is condensed in six pan batches of 10,000 pounds each. The T. S. test of the first five batches, or, iv other words, the test of the condensed product obtained from 50,000 pounds of whole milk was 26.75 per cent, and the total weight of the product 22,820 pounds. The test desired was 26.40 per cent. Therefore 22,820 x .35 per cent equals 79.87 pounds of T. S. that are overcondensed. The last pan batch should yield about 5,000 pounds of condensed product testing 26.40 per cent T. S. Since a drop of .10 degees Baume would make a correspond- ing drop of .30 per cent in T. S. in this example each .10 degree Specific Gravity 175 TABLE 29. Relation Between Specific Gravity and Composition in Evaporated Milk. wad- dell ■* 1 00 GO Q o CD CO Tt< Hh »0 CO o CM CO lO C5 d GO t- t^ CO iO ■* o o o o ^ 1 1 1 1 s o3 fO o o lO 00 CM CO CD "^ 05 CO CO CM CO T)< CD CQ 1 ] 1-H 1 1 « >i (M t^ \ Oi \ Th o o 00 00 =S.-S t^ 12 1 lO T-H CO CM Tf '-f Tt< CO CO CO CM CM o o o o o o o o I— 1 " 1 1-H 1— ( T-H '-' 1— ( 1-H 73^ Pt3 CD CO ■ O 1 CM o CM o CO CD CO 00 o C^l CO CO 00 d ,_; a> d 00 t^ d lO fo H '"' 1 6 LO ^ ' '^ l:^ C^l CM "* CO CO ^ t- CM l^ 1-H CD T-H O s O O e3 t^ w ^ CO lO lO -* tJ< < (N CD 1— 1 pq =^ >> CO 00 1 o 1— 1 o CO o CO t. ^.S CO --< ' Oi lO T-H CO CO 03 "B"> IQ 'O rtl '^ ■<* CO CO CM o O o o o o c o > T™l 1 -< -^' -^ '-' ^ o 1 i=3 &T3 CO ^ 00 CD 00 CM CO CM t^ '^ d O d 05 CO 00 d o H 1— 1 ^ 1 T-( N Q O A. 4J s 03 lO 1^ »o lO ■CO 00 CM o 00 CO ,-< 00 T CD CO CO CM O CO m w >-> GO O-l Tfl CO 03 CO GO CO GO t^ T^ O lO 1-H r- CO lO 'O lO lO ■*! -# CO CO o 9 o o o o c o ^__, '"' I— ( 1-H 1-H 1-H 1-H 1— 1 1 1 &-0 c» -H CO ^ 1 '^ CM o CM CO CI LC • 00 o Oi ^ CM CO CO 1 CM ,-, ^ d d 00 Em °o h H 1— { 1 1—1 1— 1 '"' a; s D 03 CM o ^ a: 1 <^ o «0 CD lO CO 1— ( 00 00 CO CO d CO CO W 1 05 Ol 00 ,_! o CD 00 T-H r^ CO Ol Oi lO Cft lO 1-H CD CO CD lO lO I* ^ '^f CD f3 O O o o o o o o '-' ■—I .-( I-H 1-H I-H 1-H T-H O tC m C/5 CO CK 02 CO aj W2 -ti -kJ -u -1-i -4^ •+J ■4^ H S ^ <^ H "S C^ «^-H r, 03 H ^ H <^ H «S a^ ic o o CM O CO o lO o 1-H O 00 o TJH O ^ o ■o o lO lO CD O CM lO CO o 05 >C CO O as -pa. . 00 CO 00 ■O 1-^ TjH t>- CM t-- ^ d Oi CD t^ lO CO >o CM CM ' CM CM C^l rH 1-H I-H U 176 Standardizing Evaporated Milk Baurae would correct for 15.00 pounds of T. S. Since the over- condensation amounts to 79.87 pounds, dividing this amount by 15.00 gives 5.3 or the number of .10 degees Baume necessary to deduct from the normal striking point of the last batch. The graph under Fig. 62 shows the relation between tempera- ture, specific gravity and composition in the case of evaporated milk in which tlie ratio between S. N. F. and fat is as 1 is to .4407, or T. S. to fat as 1 is to .3059. The range of composition is from 5.00 per cent fat and 16.34 per cent T. S. to 8.00 per cent fat and 26.15 per cent T. S. Several practical uses can be made of this graph as shown by the following examples : (a.) Example: What is the specific gravity of evaporated milk testing 7.80 per cent fat and 25.50 per cent T. S. at 50° F.? Answer. 1.0738. (b.) Example: What is the composition of evaporated milk in which the ratio between the S. N. F. and fat is as 1 to .4407? Baume reading 6.53. Temperature 140° F. Answer : 8.00 per cent fat and 26.15 per cent T. S. (c.) Example: The specific gravity test of evaporated milk containing 7.50 per cent fat and 24.52 per cent T. S. at 140° F. is .596 Baume. What is the Baume reading at 120° F. ? Answer: 6.77° Baume. HOW TO CALCULATE THE BAUME READING OF A CONDENSED MILK PRODUCT FOR ANY DESIRED CONDENSATION, IF THE BAUME TEST AT ANY OTHER CON- DENSATION IS KNOWN. • This method of calculation wrs devised by J. A. Cross. Calculate the weight in grams of 100 c. c. of the product of which the specific gravity and the composition are known. Also calculate the amount of water to be evaporated in order to pro- duce the desired concentration, and the volume occupied by the water to be evaporated. Then deduct the weight and the volume of the desired product from that of the known product. Obtain the specific gravity from these calculations, and in turn look up the corresponding Baume reading. Example : The Baurae test of evaporated milk containing 5.0 per cent fat and 16.35 per cent T. S. is 3.22° at 140° F, What will Specific Gravity 177 Key to Fig. 62 SPECIF/C GRAVITY /N DEGREES BAUME Pig-. 62. Relation between temperature, specific gravity and composition in the case of evaporated milk in -which the ratio between S. N. F. and fat is as 1 to .4407. Results obtained by J. A. Cross and H. J. Iiiedel. the Baume test be in the case of evaporated milk testing 8.0 per cent fat and 26.15 per cent T. S. at 140° F. ? 3.22° B. = 1.0226 specific gravity. 100 c. c. = 102.26 grams. To raise the test from 5.0 per cent to 8.0 per cent requires the evaporation of 37.5 per cent water. •100x5 100 — I I i = 37.50 V-<^)\ 100 X 8 102.26X37.50—38.34, grams water to be evaporated. The specific volume of water at 140° F. is .9834. 38.34-^9834=39, c. c. of water to be evaporated. 178 vStandardizing EvAroRATED Milk 100 — 39=61, c. c. in product desired. 102.26 — 38.34^63.92, grams in product desired. 63.92^61=1.0473,, specific gravity or 6.53° B. HOW TO STRIKE THE PAN BATCH. Several methods are available for striking the batch at the pan. These all depend upon obtaining the specific gravity of the condensed product. Two principal methods of sampling at the pan are recommended. One is by means of a sampling device at- tached to the waist of the pan. This is illustrated under Fig. 63. The second is attached to the outlet of the pan, and is illustrated under Fig. 64, It is sometimes possible to obtain the specific gravity by placing the hydrometer directly into the tube of the BOTTOM OF VACUUM PAN MILK DRAW-OFF COCK TO DROP TANK Pigf. 63. Fan Striker for Attachingr to Waist of Pan. Figf. 64. Fan Striker for Attaching' to Outlet of Pan. device attached to the waist of the pan. The most common prac- tice is to draw the sample into a hydrometer jar and to place the hydrometer directly therein. The hydrometer jar that is recom- Holding Tanp: 179 ' juiiiiimiiiifo - Pig-. 65. Hydrometer Cylinder. mended is illustrated under Fig. 65. Hydrometers with sev- eral scales are used. The one most commonly used has a range of 5 to 12 graduated into tenths upon the Baume scale. This corresponds to 1.0357 to 1.1154 upon the specific gravity scale. This type of hydrometer is illustrated under Fig. 66. Fig-. 66. Baume Hydrom^eter. HOLDING TANKS FOR STANDARDIZING EVAPORATED MILK. Two methods of handling the condensed product are possible, namely, the multibatch and the hold-over method. In the first method each pan batch is handled as one complete unit. In the hold-over method all, or a part of the total pan batches making up the day's run are mixed in one large tank. If the product is canned the same day that it is condensed, artificial refrigeration is not necessary. If the product is held over night under either method, it must be cooled to about 40^^ F. The multibach method is applicable to small plants, handling under 10,000 pounds of milk daily, while the hold-over method is applicable to all evapo- rated milk plants handling more than this amount of milk. In Fig. 67 is illustrated a jacketed copper tank very suitable to the use of small plants. Either brine or water can be used as the cooling medium. In Fig. 68 is illustrated a glass enamelled tank. These can be furnished in sizes to suit the needs of the plant, either in the horizontal or vertical type. For small tanks single propeller blade agitators, as illustrated, are very satisfac- tory for obtaining a proper mixture. For large horizontal tanks it is recommended that two propeller agitators be used — one in each end. 180 Standardizing Evaporated Milk Tig. 67. Jacketed Copper Tank. The hold-over tanks should be placed either in a refrigerated room or they should be insulated with not less than four inches of the best cork board and finished with two coats of cement plas- ter, the last coat being brought to a smooth, float finish. Tanks must be fitted with suitable thermometers, so the temperature of the milk can be properly observed at all times. THE USE OF TABLES IN SHORTENING CALCULATIONS. Much time can be saved by the use of properly prepared tables covering the products Avhich it is desired to manufacture. This cliapter contains two tables applicable to the manufacture of evaporated milk upon the double basis of 7.80 per cent of fat and 25.50 per cent of T. S., and 8.00 per cent fat and 26.15 per cent of T. S. Table 30 gives the per cent of fat and the per cent of S. N. F. in the proper ratio one to the other for standardizing both of the above products as shown in Table 25. The ratios between S. N. F. and fat in the two products are so near alike that the same values can be applied to solve problems involving either product. The Tables for Shortkning CaIvCulations 181 ■ B ^1 mKtMi table has a range from .01 to 4.99 per cent of fat and from .02 to 11.32 per cent of S. N. F. The table can be used in several ways, as follows : (1.) To deter- mine the per cent of S. N. F. required to standardize the fat in any given skim- milk. Example: Skim-milk tests .16 per cent fat. Refer- ence to the table shows that .36 per cent of S. N. F. is re- quired to standardize .16 per cent of fat. (2.) To determine the per cent of fat required to standard- ize the S. N. F. in any given cream. Example : Cream tests 7.10 per cent of S. N. F. Reference to the table shows that 3.13 per cent of fat is required to standardize 7.10 per cent of S. N. F. (3.) To determine the per cent of fat required to standardize the S. N. F. in any given whole milk or vice versa. Example : Whole milk tests 4,00 per cent of fat. Reference to the table shows that 9.08 per cent of S. N. F. are required to standardize 4.00 per cent of fat. The same results as given in the table can be obtained by multi- plying the per cent of fat by .4407, or by dividing the per cent of S. N. F. by .4407, but the use of the table dispenses with these long calculations and helps to prevent errors. This table is in- tended primarily for use when standardizing before condens- ing, although it can sometimes be applied in part upon some prob- lems covering standardization after condensing. This applies par- ticularly to the use of cream as in the example given above. Fig". 68. Glass Enameled Tank. Courtesy of the Pfaudler Co. 182 Standardizing Evaporated Mii,k TABLE 30. Per cents fat and S. N. F. in the proper ratio to standardize evaporated milk upon the basis of either 7.80 per cent of fat and 25.50 per cent of T. S. or 8.00 per cent of fat and 26.15 per cent of T. S. Ratio being 1 S. N. F. to .4407 fat. Per Cent Fat Per Cent S. N. F. Per Cent Fat Per Cent S. N. F. Per Cent Fat Per Cent S. N. F. Per Cent Fat Per Cent S. N. F. .01 .02 .40 .91 .78 1.77 1.17 2.65 .02 .05 .41 .93 .79 1.79 1.18 2.68 .03 .07 .42 .95 .80 1.82 1.19 2.70 .04 .09 .43 .98 .81 1.84 1.20 2.72 .05 .11 .44 1.00 .82 1.86 1.21 2.75 .06 .14 .45 1.02 .83 1.88 1.22 2.77 .07 .16 .46 1.04 .84 1.91 1.23 2.79 .08 . .18 .47 1.07 .85 1.93 1.21 2.81 .09 .20 .48 1.09 .86 1.95 1.25 2.84 .10 .23 .49 1.11 .87 1.97 1.26 2.86 .11 .25 .50 1.13 .88 2.00 1.27 2.88 .12 .27 .51 1.16 .89 2.02 1.28 2.90 .13 .29 .52 1.18 .90 2.04 1.29 2.93 .14 .32 .53 1.20 .91 2.06 1.30 2.95 .15 .34 .54 1.23 .92 2.09 1.31 2.97 .16 .36 .55 1.25 .93 2.11 1.32 3.00 .17 .39 .56 1.27 .94 2.13 ■ 1.33 3.02 .18 .41 .57 1.29 .95 2.16 1.34 3.04 .19 .43 .58 1.32 .96 2.18 1 . 35 3.06 .20 .45 .59 1.34 .97 2.20 1.36 3.09 .21 .48 .60 1.36 .98 2.22 1.37 3.11 .22 .50 .61 1.38 .99 2.25 1.38 3.13 .23 .52 .62 1.41 1.00 2.27 1.39 3.15 .24 .54 .63 1.43 1.01 2.29 1.40 3.18 .25 .57 .64 1.45 1.02 2.31 1.41 3.20 .26 .59 .65 1.47 1.03 2.34 1.42 3.22 .27 .61 .66 1.50 1.04 2.36 1.43 3.24 .28 .64 .67 1.52 1.05 2.38 1.44 3.27 .29 .66 fiS 1 "14 1.06 2.41 1.45 3.29 .30 .68 .69 .70 .71 i. . Ot: 1.57 1.59 1.61 1.07 2.43 1.46 3.31 .31 .70 1.08 2.45 1.47 3.34 .32 .33 .73 .75 1.09 1.10 2.47 2.50 1.48 1.49 3.36 3.38 .34 .77 .72 1.63 1.11 2.52 1.50 3.40 .35 .79 .73 1.66 1.12 2.54 1.51 3.43 .36 .82 .74 1.68 1.13 2.56 1.52 3.45 .37 .84 .75 1.70 1.14 2.59 1.53 3.47 .38 .86 .76 1.72 1.15 2.61 1.54 3.49 .39 .88 .77 1.75 1.16 2.63 1.55 3.52 Tables for Shortening Calculations TABLE 30 (Continued). 183 Per Cent Fat Per Cent S. N. F. Per Cent Fat Per Cent S. N. F. Per Cent Fat Per Cent S. N. F. Per Cent Fat Per Cent S. N. F- 1.56 3.54 2.00 4.54 2.44 5.54 2.88 6.54 1.57 3.56 2.01 4.56 2.45 5.56 2.89 6.56 1.58 3.59 2.02 4.58 2.46 5.58 2.90 6.58 1.59 3.61 2.03 4.61 2.47 5.60 2.91 6.60 1.60 3.63 2.04 4.63 2.48 5.63 2.92 6.63 1.61 3.65 2.05 4.65 2.49 5.65 2.93 6.65 1.62 3.68 2.06 4.67 2.50 5.67 2.94 6.67 1.63 3.70 2.07 4.70 2.51 5.70 2.95 6.69 1.64 3.72 2.08 4.72 2.52 5.72 2.96 6.72 1.65 3.74 2.09 4.74 2.53 5.74 2.97 6.74 1.66 3.77 2.10 4.77 2,54 5.76 2.98 6.76 1.67 3.79 2.11 4.79 2.55 5.79 2.99 6.78 1.68 3.80 2.12 4.81 2.56 5.81 3.00 6.81 1.69 3.83 2.13 4.83 2.57 5.83 3.01 6.83 1.70 3.86 2.14 4.86 2.58 5.85 3.02 6.85 1.71 3.88 2.15 4.88 2.59 5.88 3.03 6.88 1.72 3.90 2.16 4.90 2.60 5.90 3.04 6.90 1.73 3.93 2.17 4.92 2.61 5.92 3.05 6.92 1.74 3.95 2.18 4.95 2.62 5.95 3.06 6.94 1.75 3.97 2.19 4.97 2.63 5.97 3.07 6.97 1.76 3.99 2.20 4.99 2.64 5.99 3.08 6.99 1.77 4.02 2.21 5.01 2.65 6.01 3.09 7.01 1.78 4.04 2.22 5.04 2.66 6.04 3.10 7.03 1.79 4.06 2.23 5.06 2.67 6.06 3.11 7.06 1.80 4.08 2.24 5.08 2.68 6.08 3.12 7.08 1.81 4.11 2.25 5.11 2.69 6.10 3.13 7.10 1.82 4.13 2.26 5.13 2.70 6.13 3.14 7.13 1.83 4.15 2.27 5.15 2.71 6.15 3.15 7.15 1.84 4.18 2.28 5.17 2.72 6.17 3.16 7.17 1.85 4.20 2.29 5.20 2.73 6.19 3.17 7.19 1.86 4.22 2.30 5.22 2.74 6.22 . 3.18 7.22 1.87 4.24 2.31 5.24 2.75 6.24 3.19 7.24 1.88 4.27 2.32 5.26 2.76 6.26 3.20 7.26 1.89 4.29 2.33 5.29 2.77 6.29 3.21 7.28 1.90 4.31 2.34 5.31 2.78 6.31 3.22 7.31 1.91 4.33 2.35 5.33 2.79 6.33 3.23 7.33 1.92 4.36 2.. 36 5.36 2.80 6.35 3.24 7.35 1.93 4.38 2.37 5.38 2.81 6.38 3.25 7.37 1.94 4.40 2.. 38 5.40 2.82 6.41 3.26 7.40 1.95 4.42 2.39 5.42 2.83 6.42 3.27 7.42 1.96 4.45 2.40 5.44 2.84 6.44 3.28 7.44 1.97 4.47 2.41 5.47 2.85 6.47 3.29 7.47 1.98 4.49 2.42 5.49 2.86 6.49 3.30 7.49 1.99 4.52 2.43 5.51 2.87 6.51 3.31 7.51 18^ Standardizing Evaporated Milk TABLE 30 (Continued). Per Cent Fat Per Cent S. N. F. Per Cent Fat Per Cent S. N. F. Per Cent Fat Per Cent S. N. F. Per Cent Fat Per Cent S. N. F. 3.32 7.53 3.74 8.49 4.16 9.44 4.58 10.39 3.33 7.56 3.75 8.51 4.17 9.46 4.59 10.42 3.34 7.58 3.76 8.53 4.18 9.49 4.60 10.44 3.35 7.60 3.77 8.55 4.19 9.51 4.61 10.46 3.36 7.62 3.78 8.58 4.20 9.53 4.62 10.48 3.37 7.65 3.79 8.60 4,21 9.56 4.63 10.51 3.38 7.67 3.80 8.62 4.22 9.58 4.64 10.53 3.39 7.69 3.81 8.65 4.23 9.60 4.65 10.55 3.40 7.72 3.82 8.67 4.24 9.62 4.66 10.57 3.41 7.74 3.83 8.69 4.25 9.64 4.67 10.60 3.42 7.76 3.84 8.71 4.26 9.67 4.68 10.62 3.43 7.78 3.85 8.74 4.27 9.69 4.69 10.64 3.44 7.81 3.86 8.76 4.28 9.71 4.70 10.67 3.45 8.83 3.87 8.78 4.29 9.73 4.71 10.69 3.46 7.85 3.88 8.80 4.30 9.76 4.72 10.71 3.47 7.87 3.89 8.83 4.31 9.78 4.73 10.73 3.48 7.90 3.90 8.85 4.32 9.80 4.74 10.76 3.49 7.92 3.91 8.87 4.33 9.83 4.75 10.78 3.50 7.94 3.92 8.90 4.34 8.85 4.76 10.80 3.51 7.96 3.93 8.92 4.35 9.87 4.77 10.82 3.52 7.99 3.94 8.94 4.36 9.89 4.78 10.85 3.53 7.01 3.95 8.96 4.37 9.92 4.79 10.86 3.54 8.03 3.96 8.99 4.38 9.94 4.80 10.89 3.55 8.06 3.97 9.01 4.39 9.96 4.81 10.91 3.56 8.08 3.98 9.03 4.40 9.98 4.82 10.94 3.57 8.10 3.99 9.05 4.41 10.01 4.83 10.96 3.58 8.12 4.00 9.08 4.42 10.13 4.84 10.98 3.59 8.15 4.01 9.10 4.43 10.05 4.85 11.01 3.60 8.17 4.02 9.12 4.44 10.08 4.86 11.03 3.61 8.19 4.03 9.14 4.45 10.10 4.87 11.05 3.62 8.21 4.04 9.17 4.46 10.12 4.88 11.07 3.63 8.24 4.05 9.19 4.47 10.14 4.89 11.10 3.64 8.26 5.06 9.21 4.48 10.17 4.90 11.12 3.65 8.28 4.07 9.24 4.49 10.19 4.91 11.14 3.66 8.31 4.08 9.26 4.50 10.21 4.92 11.16 3.67 8.33 4.09 9.28 4.51 10.23 4.93 11.19 3.68 8.35 4.10 9.30 4.52 10.26 4.94 11.21 3.69 8.37 4.11 9.33 4.53 10.28 4.95 11.23 3.70 8.40 4.12 9.35 4.54 10.30 4.96 11.26 3.71 8.42 4.13 9.37 4.55 10.32 4.97 11.28 3.72 8.44 4.14 9.39 4.56 10.35 4.98 11.30 3.73 8.46 4.15 9.42 4.57 10.37 Tablks for Shortening Calcul.xtions 18: TABLE 31. Percentages of fat, S. N. F. and T. S. in product after condensing, all in the proper ratio to standardize upon the basis of either 7.80 per cent of fat and 25.50 per cent of T. S., or 8.00 per cent of fat and 26.15 per cent of T. S. Ratio in either case being 1 S. N. F. to .4407 of fat. Also the factor of over- condensation fiom 7.80 to 9.00 per cent, and from 8.00 to 9.00 per cent of fat. S. N. F. T. S. Over- condensation Fat S. N. F. T. S. OVEB- CONDENSATION Fat 7.80- 25.50 Standard 8.00 26.15 Standard 7.80- 25,50 Standard 8.00- 26.15 Standard 7.00 15.88 15.89 15.90 15.91 15.92 15.93 15.94 15.95 15.96 15.97 15.98 15.99 16.00 16.01 16.02 16.03 16.04 16.05 16.06 16.07 16.08 16.09 16.10 16.11 16.12 16.13 16.14 16.15 16.16 16.17 16.18 16.19 16.20 16.21 16.22 22.88 22.89 22.91 22.92 22.94 22.95 22.96 22.98 22.99 23.01 23.02 23.04 23.05 23.07 23.08 23.09 23.11 23.12 23.14 23.15 23.17 23.18 23.20 23.21 23.22 23.24 23.25 23.27 23.28 23.30 23.31 23.32 23.34 23.35 23,37 7.15 7.16 7.16 7.17 7.17 7.17 7.18 7.18 7.19 7.19 7.20 7.20 7.21 7.21 7.21 7.22 7.22 7.23 7.24 7.24 7.25 7.25 7.25 7.26 7.26 7.27 7.27 7.28 7.28 7.28 7.29 7.29 7.30 7.30 7.31 16.23 16.24 16.25 16.26 16.27 16.28 16.29 16,30 16.31 16.32 16.33 16.34 16.35 16.36 16.37 16.38 16.39 16.40 16.41 16.42 16.43 16.44 16.45 16.46 16.47 16.48 16.49 16.50 16.51 16.52 16.53 16.54 16.55 16.56 16.57 23.38 23.40 23.41 23.42 23.44 23.45 23.47 23.48 23.50 23.51 23.53 23.54 23.56 23.57 23.58 23.60 23.61 23.63 23.64 23.66 23.67 23.69 23.70 23.71 23.73 23.74 23.76 23.77 23.79 23.80 23.81 23.83 23.84 23.86 23.87 7.00 7.01 7.01 7.02 7.02 7.02 7.03 7.03 7.04 7.04 7.05 7.05 7.06 7.06 7.06 7.07 7.07 7.08 7.08 7.09 7.09 7.10 7.10 7.10 7.11 7.11 7 12 7 12 7.13 7 13 7 13 7.14 7.14 7.15 Standardizing Evaporated ^IiLi^ TABLE 31 (Continued). Tables i-'or Shortkninc Calculations TABLE 31 (Continued). 187 S. N. F. T. S. Over- condensation Fat S. N. F. T. S. Over- condensation Fat 7.80- 25.50 Standard 8.00- 26.15 Standard 7.80- 25.50 Standard 8.00 26.15 Standard 7.67 17.40 25.07 7.85 17.82 25.67 .0066 7.67 17.41 17.42 17.43 17.44 25.08 25.10 25.11 25.13 7.86 7.86 7.87 7.87 17.83 17.84 17.85 17.88 25.69 25.70 25.72 25.73 .0074 .0078 .0086 .0090 7.68 7.68 7.69 7.69 17.45 17.46 17.47 17.48 17.49 17.50 17.51 25.14 25.15 25.17 25.18 25.20 25.21 25.23 7.88 7.88 7.88 7.89 7.89 7.90 7.90 17.87 17.86 17.89 17.90 17.91 17.92 17.93 25.75 25.76 25.77 25.79 25.80 25.82 25.83 .0098 .0101 .0105 .0113 .0117 .0125 .0129 7.69 7.70 7.70 7.71 7.71 7.72 7.72 17.52 17.53 17.54 17.55 17.56 17.57 17.58 17.59 17.60 17.61 17.62 17.63 17.64 17.65 17.66 17.67 17.68 17.69 17.70 17.71 25.24 25.26 25.27 25.28 25.30 25.31 25.33 25.34 25.36 25.37 25.39 25.40 25.41 25.43 25.44 25.46 25.47 25.49 25.50 25.61 7.91 7.91 7.91 7.92 7.93 7.93 7.93 7.94 7.94 7.95 7.95 7.95 7.96 7.96 7.97 7.97 7.98 7.98 7.99 7.99 17.94 17.95 17.96 17.97 17.98 17.99 18.00 18.01 18.02 18.03 18.04 18.05 18.06 18.07 18.08 18.09 18.10 18.11 18.12 18.13 25.85 25.86 25.87 25.89 25.90 25.92 25.93 25.95 25.96 25.98 25.99 26.00 26.02 26.03 26.05 26.06 26.08 26.09 26.11 26.12 .0137 .0141 .0145 .0152 .0156 .0164 .0168 .0176 .0180 .0188 .0192 .0196 .0203 .0207 .0215 .0219 .0227 .0231 .0239 .0243 7.73 7.73 7.73 7.74 7.74 7.75 7.75 7.76 7.76 7.77 7.77 7.77 7.78 7.78 7.79 7.79 7.80 7.80 7.80 .0004 7.81 17.72 25.52 .0007 7.99 18.14 26.13 .0246 7.81 17.73 25.54 .0015 8.00 18.15 26.15 .0254 7.82 17.74 25.56 .0023 8.00 18.16 26.16 .0258 .0004 7.82 17.75 25.57 .0027 8.01 18.17 26.18 .0266 .0008 7.83 17.76 25.59 .0035 8.01 18.18 26.19 .0270 .0015 7.83 17.77 25.60 .0039 8.02 18.19 26.21 .0278 .0023 7.84 17.78 25.62 .0047 8.02 18.20 26.22 .0282 .0027 7.84 17.79 25.63 .0050 8.03 18.21 26.24 .0290 .0034 7.84 17.80 25.64 .0054 8.03 18.22 26.25 .0294 .0038 7.85 17.81 25.66 .0062 8.03 18.23 26.26 .0297 .0042 188 Standardizing Evaporated Milk TABLE 31 (Continued). S. F. F. T. S. OVER- CONDEN8ATION- Fat S, N, F, T. S. Over- condensation Fat 7.80- 25 . .50 Standard 8.00- 26.15 Standard 7.80- 25 . 50 Standard 8.00- 26.15 Standard 8.04 18.24 26.28 .0305 .0050 8.22 18.66 26.88 .0540 .0279 8.04 18.25 26.29 .0309 .0054 8.23 18,67 26.90 .0548 .0287 8.05 18.26 26.31 .0317 .0061 8.23 18,68 26.91 .0552 .0291 8.05 18.27 26.32 .0321 .0065 8.24 18.69 26.23 .0560 ,0298 8.06 18.28 26.34 .0329 .0073 8,24 18,70 26.94 ,0564 ,0302 8.06 18.29 26.35 .0333 .0076 8,25 18.71 26.96 ,0572 ,0310 8.06 18.30 26.36 .0337 .0080 8,25 18.72 26.97 .0576 ,0314 8.07 18.31 26.38 .0344 .0088 8.25 18.73 26.98 .0580 .0317 8.07 18.32 26.39 .0348 .0092 8,26 18.74 27.00 .0588 ,0325 8.08 18.33 26.41 .0356 .0099 8,26 18.75 27.01 ,0591 .0329 8.08 18.34 26.42 .0360 . 0103 8,27 18.76 27.03 .0599 .0336 8.09 18.35 26.44 .0366 ,0111 8,27 18.77 27.04 .0603 .0340 8.09 18.36 26.45 .0372 .0115 8,28 18.78 27.06 ,0611 .0348 8.10 18.37 26.47 .0380 ,0122 8.28 18,79 27.07 ,0615 .0352 8.10 18.38 26.48 .0384 .0126 8,29 18,80 27.09 .0623 ,0359 8.10 18.39 26.49 .0388 ,0130 8.29 18,81 27,10 .0627 .0363 8.11 18.40 26.51 .0395 .0133 8,29 18,82 27,11 .0631 ,0667 8.11 18.41 26.52 .0400 ,0141 8.30 18,83 27 , 13 .0338 .0375 8.12 18.42 26.54 .0407 .0149 8.30 18,84 27,14 .0642 .0379 8.12 18.43 26.55 .0412 .0153 8,31. 18,85 27,16 .0650 .0386 8.13 18.44 26.57 .0417 .0161 8,31 18,86 27,17 .0654 .0390 8.13 18.45 26.58 .0423 .0164 8,32 18,87 27,19 .0662 .0398 8.14 18.46 26.60 .0431 .0172 8,32 18.88 27,20 .0666 .0402 8.14 18.47 26.61 .0435 .0176 8.32 18.89 27,21 .0670 .0407 8.14 18.48 26.62 .0439 .0180 8,33 18.90 27.23 .0678 .0413 8.15 18.49 26.64 .0446 .0187 8,33 18.91 27,24 .0682 ,0417 8.15 18.50 26.65 .0450 .0191 8.34 18.92 27,26 .0689 .0424 8.16 18.51 26.67 .0458 .0199 8,34 18.93 27,27 .0693 .0428 8.16 18.52 26.68 .0462 .0203 8,35 18.94 27,29 .0701 , 0436 8.17 18.53 26.70 .0470 .0210 8,35 18.95 27,30 .0705 ,0440 8.17 18.54 26.71 .0471 .0214 8.36 18,96 27,32 .0713 .0447 8.17 18.55 26.72 .0478 .0218 8,36 18,97 27,33 .0717 ,0451 8.18 18.56 26.74 .0486 .0226 8.36 18,98 27,34 .0721 .0455 8.18 18.57 26.75 .0490 .0229 8,37 18,99 27,36 .0729 .0463 8.19 18.58 26.77 .0497 .0237 8,37 19,00 27,37 . 0733 .0467 8.19 18.59 26.78 .0501 .0241 8,38 19,01 27,39 .0740 .0474 8.20 18.60 26 . 80 .0509 .0249 8.38 19,02 27,40 .0744 .0478 8.20 18.61 26.81 ,0513 .0252 8,39 19,03 27,42 .0752 .0486 8.21 18.62 26.83 .0521 .0260 8,39 19,04 27,43 . 0756 .0489 8.21 18.63 26.84 .0525 .0264 8,39 19,05 27.45 .0764 .0497 8.21 18.64 26.85 ,0529 .0268 8,40 19.06 27.46 .0768 .0501 8.22 18.65 26.87 .0537 .0275 8,40 19.07 27.47 .0772 .0505 Tables for vShortkning Calculations TABLE 31 (Continued). 189 Over- Over- condensation condensation Fat S. N. F. T. S. 7.80- 25.50 Standard 8.00- 26.15 Standard Fat S. N. F. T. S. 7.80- 25.50 Standard 8.00- 26.15 Standard 8.41 19.08 27.49 .0780 .0512 8.59 19.50 28.09 .1015 .0742 8.41 19.09 27.50 .0784 .0516 8.60 19.51 28.11 . 1023 .0750 8.42 19.10 27.52 .0792 .0524 S.60 19.52 28.12 .1027 .0753 8.42 19.11 27.53 .0796 .0528 S.61 19.53 28.14 . 1035 .0761 8.43 19.12 27.55 .0803 .0535 8.61 19.54 28.15 . 1039 .0765 8.43 19.13 27.56 .0807 . 0539 8.62 19.55 28.17 .1047 .0772 8.43 19.14 27.57 .0811 .0543 8.62 19.56 28.18 .1050 .0776 8.44 19.15 27.59 .0819 .0551 8.62 19.57 28.19 .1054 .0780 8.44 19.16 27.60 .0823 .0554 8.63 19.58 28.21 .1062 .0788 8.45 19.17 27.62 .0831 .0562 8.63 19.59 28.22 .1066 .0792 8.45 19.18 27.63 .0835 .0566 8.64 19.60 28.24 .1074 .0799 8.46 19.19 27.65 .0843 .0574 8.64 19.61 28.25 .1078 .0803 8.46 19.20 27.66 .0847 .0577 8.65 19.62 28.27 .1086 .0811 8.47 19.21 27.68 .0854 .0585 8.65 19.63 28.28 .1090 .0815 8.47 19.22 27.69 .0858 .0589 8.66 19.64 28.30 .1098 .0822 8.47 19.23 27.70 .0862 .0593 8.66 19.65 28.31 .1101 .0826 8.48 19.24 27.72 .0870 .0600 8.66 19.66 28.32 .1105 . 0830 8.48 19.25 27.73 .0874 .0604 8.67 19.67 28.34 .1113 .0837 8.49 19.26 27.75 .0882 .0612 8.67 19.68 28.35 .1117 .0841 8.49 19.27 27.76 .0886 .0616 8.68 19.69 28.37 .1125 .0849 8.50 19.28 27.78 .0894 .0623 8.68 19.70 28.38 .1129 .0853 8.50 19.29 27.79 .0898 .0627 8.69 19.71 28.40 .1137 .0860 8.51 19.30 27.80 .0901 .0631 8.69 19.72 28.41 .1141 .0864 8.51 19.31 27.82 .0909 .0639 8.70 19.73 28.43 .1149 .0872 8.51 19.32 27.83 .0913 .0642 8.70 19.74 28.44 .1152 .0876 8.52 19.33 27.85 .0921 .0650 8.70 19.75 28.45 .1156 .0880 8.52 19.34 27.86 .0925 .0654 8.71 19.76 28.47 .1164 .0887 8.53 19.35 27.88 .0933 .0661 8.71 19.77 28.48 .1168 .0891 8.53 19.36 27.89 .0937 .0665 8.72 19.78 28.50 .1176 .0899 8.54 19.37 27.91 .0945 .0673 8.72 19.79 28.51 .1180 . 0902 8.54 19.38 27.92 .0949 .0677 8.73 19.80 28.53 .1188 .0910 8.55 19.39 27.94 .0956 .0685 8.73 19.81 28.54 .1192 .0914 8.55 19.40 27.95 .0960 .0688 8.73 19.82 28.55 .1195 .0918 8.55 19.41 27.96 .0964 .0392 8.74 19.83 28.57 .1203 .0925 8.56 19.42 27.98 .0972 .0700 8.74 19.84 28.58 .1207 .0929 8.56 19.43 27.99 .0976 .0704 8.75 19.85 28.60 .1215 .0937 8.57 19.44 28.01 .0984 .0711 8.75 19.86 28.61 .1219 .0941 8.57 19.45 28.02 .0988 .0715 8.76 19.87 28.63 .1227 .0948 8.58 19.46 28.04 .0996 .0723 8.76 19.88 28.64 .1231 .0952 8.58 19.47 28.05 .1000 .0727 8.77 19.89 28.66 . 1239 .0960 8.58 19.48 28.06 .1003 .0730 8.77 19.90 28.67 . 1243 .0964 8.59 19.49 28.08 .1011 .0738 8.77 19.91 28.68 .1247 .0967 190 Standardizing Evaporatiid Milk TABLE 31 [Continued). Fat S. N. F. T. S. Over- condensation Fat S. N. F. T. S. OVEB- C0NDEN.?ATrON 7.80- 25.50 Standard 8.00- 26.15 Standard 7.80- 25,50 Standard S( 8 00- 26.15 andard 8.78 19.92 28.70 . 1254 .0975 8.89 20.18 29.07 .1400 1117 8.78 19.93 28.71 .1258 .0979 8.90 20.19 29.09 .1407 1124 8.79 19.94 28.73 .1266 .0987 8.90 20.20 29.10 .1411 1128 8.79 19.95 28.74 .1270 .0990 8.91 20.21 29.12 .1419 1136 8.80 19.96 28.76 .1278 .0998 8.91 20.22 29.13 .1423 1140 8.80 19.97 28.77 .1282 .1002 8.92 20.23 29.15 .1431 1147 8.81 19.98 28.79 .1290 .1010 8.92 20.24 29.16 . 1435 1151 8.81 19.99 28.80 .1294 . 1013 8.92 20.25 29.17 .1443 1155 8.81 20.00 28.81 .1298 .1017 8.93 20.26 29.19 .1447 1163 8.82 20.01 28.83 . 1305 .1025 8.93 20.27 29.20 .1450 1166 8.82 20.02 28.84 . 1309 .1029 8.94 20.28 29.22 .1458 1174 8.83 20.03 28.86 .1317 . 1036 8.94 20.29 29.23 •. 1462 1178 8.83 20.04 28.87 . 1321 .1040 8.95 20.30 29.25 .1470 1185 8.84 20.05 28.89 .1329 .1048 8.95 20.31 29.26 .1474 1189 8.84 20.06 28.90 . 1333 .1052 8.96 20.32 29.28 .1483 1197 8.84 20.07 28.91 .1337 .1058 S.96 20.33 29.29 .1486 1201 8.85 20.08 28.93 . 1345 .1063 8.96 20.34 29.30 .1490 1205 8.85 20.09 28.94 .1349 .1067 8.97 20.35 29.32 .1498 1212 8.86 20.10 28.96 .1356 .1075 8.97, 20.36 29.33 . 1501 1216 8.86 20.11 28.97 .1360 .1078 8.98 20.37 29.35 .1509 1224 8.87 20.12 28.99 .1368 .1086 8.98 20.38 29.36 .1513 1228 8.87 20.13 29.00 .1372 .1090 S.99 20.39 29.38 .1521 1235 8.88 20.14 29.02 .1380 .1098 8.99 20.40 29.39 .1525 12.39 8.88 20.15 29.03 .1384 .1101 8.99 20.41 29.40 .1529 1243 8.88 20.16 29.04 .1388 .1105 9.00 20.42 29.42 .1537 1250 8.89 20.17 29.06 .1396 .1113 Table 31 gives the percentage of fat, S. N. F. and T. S. all in the proper ratio one to the other for standardizing evaporated milk upon the double basis of 7.80 per cent of fat, and 25.50 per cent of T. S., and 8.00 per cent of fat and 26.15 per cent of T. S. The table has a range from 7.00 per cent to 9.00 per cent of fat, and from 15.88 per cent to 20.52 per cent of S. N. F. The table also gives the factor of overcondensation from 7.80 to 9.00 and from 8.00 to 9.00. This table is intended to be used when standardizing after condensing, and also when standardizing with the use of con- densed milk products. One example will suffice to show its use. Example : Evaporated milk after condensing contains 8.25 per IvEY TO Formulas 191 Cent of fat and 19.21 per cent S. N. F. Reference to the table shows that for 8.25 per cent of fat the S. N. F. should be 18.71 per cent. The difference between 19.21 and 18.71 is .50 or the per cent of S. N. F. that is to be standardized. The table gives results that could not be obtained otherwise than by a long calculation, and it also helps to prevent errors. The method for applying the factor of overcondensation will be discussed in another paragraph of this chapter, KEY TO FORMULAS FOR STANDARDIZING EVAPORATED MILK. The following key gives the information required for substi- tuting values or figures for letters in the formulas found in this chapter : A = The desired per cent of fat in the standardized product. B = The desired per cent of S. N, F. in the standardized product. B^ = The per cent of S. N. F. in evaporated milk, before standard- izing. C = The desired per cent of T. S. in the standardized product. D ~ The per cent of T. S. in condensed whole milk. D^ = The pounds of evaporated milk, before standardizing. D-= The pounds of unsweetened condensed whole milk. F = The per cent of fat in the whole milk. F^ ^ The per cent of fat in butter. G = The per cent of fat in the cream. J = The per cent of S. N. F. in the cream. J' — The per cent of T. S. in the cream. J- — - The per cent of S. N. F. in the evaporated milk before stand- ardizing. K^ := The per cent of fat in the skim-milk. K- = The per cent of fat in the evaporated milk, before standard- izing. K = The per cent of fat in the unsweetened condensed whole milk. L =: The pounds of skim-milk required. L^ = The pounds of unsweetened condensed skim-milk. M = The per cent of S. N. F. in the condensed whole milk. N =r The per cent of S. N. F. in the skim-milk. = The pounds of cream required. 0^ = The per cent of T. S. in the mixed batch. 192 Standardizing Evaporatrd AIilk P =z The pounds of whole milk in the batch. pi rzi The pounds of butter. Q = The per cent of S. N. F. in the condensed skim-railk, R =: The desired ratio of S. N. F. to fat. Ri = The desired ratio of T. S. to fat. S = The per cent of S. N. F. in the whole milk. S^ =r The average per cent of fat in the mixed batch. S- = The average per cent of S. N. F, in the mixed batch. T = The per cent of T. S. in whole milk. T^ = The per cent of T. S. in evaporated milk. T-= The per cent of T. S. in "condensed skim-milk. W;= The pounds of water to be added. PROVIDING FACTOR OF SAFETY. In all the problems given, the calculations are made upon the basis of the absolute standard without allowing any factor of safety. It is recommended that in practice, in the case of evapo- rated milk, a factor of safety of about .05 per cent of fat, and about .20 per cent of T. S. be allowed. When plenty of time is available for retests this factor of safety may be very slightly reduced. PROBLEM 7. STANDARDIZING EVAPORATED MILK BEFORE CONDENSING. HOW TO CALCULATE POUNDS OF SKIM-MILK TO ADD TO WHOLE MILK. The ratio between the percentage of S. N. F. and the percen- tage of fat in the whole milk must be more than the required ratio. Solution of Problem 7, Based Upon Rule 4: (1.) Divide the percentage of fat in the skim-milk b}' the ra- tio between the S. N. F. and the fat in the product desired. Sub- tract answer from the S. N. F. in the skim-milk. Call remainder A., or the percentage of 8. N. F. in the skim-milk available for standardizing. (2.) Divide the percentage of fat in the whole milk by the ratio between the S. N. F. and the fat in the product desired. Call the result B. Subtract from B the percentage of S. N. F. present in the whole milk. Multiply the remainder by the pounds of Probi,i;ms Before Condensing 193 whole milk present in the batch. Call the result C, or the pounds S. N.F. short. (3.) Divide C by A. The answer will be the pounds of skim- milk necessary to standardize the batch to the required ratio. Solution of Problem 7, Based Upon Formula 6 : N — R Problem 7, Example 9 : Pounds Per Cent Products Fat S. N. F. T. S. Milk 10,000 3.79 .16 7.80 8.31 8.47 17,70 12.10 Skim-milk 8.63 Composition desired 25.50 Ratio 1 S. N. F. to .4407 fat desired. Ratio 1 S. N. F. to .4561 fat in whole milk. Solution of Problem 7, Example 9, Based Upon Rule 4 : (1.) To calculate the available S. N. F, in the skim-milk. .16 -f- .4407 = .36, per cent of S. N. F. required to equalize the fat in the skim-milk. 8.47 — .36=8.11, per cent of S. N. F. available for standardizing. (2.) To calculate the pounds of S. N. F. short. 3.79 ~ .4407 = 8.60, per cent of S. N. F. required. 8.60 — 8.31 = .29, per cent of S. N. F. short. 10000 X .0029 = 29, pounds of S. N. F. short. (3.) To calculate the pounds of skim-milk required. 29-:-.0811=358, pounds of skim-milk required. 194 Standardizing Evaporated Milk Solution of Problem 7, Based Upon Formula 6: .0379 — .usyi I X iu,uuu 358 V .4407 / .0847 .0016 .4407 Proof of Problem 7, Example 9 : Pound Pounds Per Cent Products Fat S. N. F. T. S. Fat S. N. F. T. S. Milk 10,000 t,358 10,358 379 1 80 831 30 861 1210 31 124 3.79 .16 3.66 8.31 8.47 8.31 12.10 Skim-milk 8.63 Standardized product 11.01 Ratio 1 S. N. F. to .4407 fat obtained in product after stand- ardizing. STANDARDIZING EVAPORATED MILK BEFORE CONDENSING. Problem 8 : How to Calculate Pounds of Cream to Add to Whole Milk: Ratio between the percentage of S. N. F. and fat in the whole milk must be less than the required ratio. Solution of Problem 8, Based Upon Rule 5 : (1.) Multiply the percentage of S. N. F. in the cream by the ratio between the S. N. F. and the fat in the product desired. Subtract the result from the percentage of fat in the cream. Call the reminder A, or the percentage of fat in the cream available for standardizing. (2.) Multiply the percentage of S. N. F. in the whole milk by the ratio between the S. N. F. and the fat in the product desired. Call the result B, or the percentage of fat required. Subtract from B the percentage of fat in the whole milk. Multiply the remain- der by the pounds of whole milk in the batch. Call the result C, or the pounds of fat short. Probli;ms Before Condensing 195 3. Divide C by A. The answer will be the pounds of cream required to standardize the batch to the desired ratio. Solution of Problem 8, Based Upon Formula 7: [(SR)— F] P = Problem 8, Example 10 : G— (JR) Products Pounds Per Cent Fat S. N. F. T. S. Milk Cream 10,000 3.35 26.38 7.80 8.63 6.44 17.70 11.98 32.82 Composition desired after condensing 25.50 Ratio of 1 S. N. F. to .4407 fat desired. Ratio of 1 S. N. F. to .3793 fat in whole milk. Solution of Problem 8, Example 10, Based Upon Rule 5 : (1.) To calculate the available fat in the cream. 6.44 X .4407 = 2.84, per cent of fat required to equalize the S. N. F. in the cream. 26.38 — 2.84 = 23.54, per cent of fat available for standardizing. (2.) To calculate the pounds of fat short. 8.63 X .4407 = 3.80, per cent of fat required. 3.80 — 3.35 = .45, per cent of fat short. lOOOOX. 0045=45, pounds of fat short. (3.) To calculate the pounds of cream required. 45-^,2354=192, pounds of cream required. 196 Standardizing Evaporated Milk Solution of Problem 8, Example 10, based upon Formula 7 : (. 0863 X. 4407)— .0335] X 10,000 = .2638— (.0644 X -4407) Proof of Problem 8, Example 10 : :192 Pounds Pounds Per Cent Products Fat S. N. F. T. S. Fat S. N. F. T. S. Milk 10,000 192 10,192 335 51 386 863 12 875 1198 63 1261 3.35 26.38 3.79 8.63 6.44 8.59 11.98 Cream 32.82 Standardized product 12.38 Ratio 1 S. N. F. to .4407 fat obtained in product after stand- ardizing. STANDARDIZING EVAPORATED MILK BEFORE CONDENSING. Problem 9; How to Calculate the Pounds of Cream to Add to Skim-milk. Solution of Problem 9, Based Upon Rule 6 : (1.) Multiply the percentage of S. N. F. in the cream by the ratio between the S. N. F. and the fat in the product desired. Subtract the result from the percentage of fat in the cream. Call the remainder A, or the percentage of fat in the cream avail- able for standardizing. (2.) Multiply the percentage of S. N. F. in the skim-milk by the ratio between the S. N. F. and the fat in the product desired. Call the result B. Subtract from B the percentage of fat in the skim-milk. Multiply the remainder by the pounds of skim-milk in the batch. Call the result C. (3.) Divide C by A. The answer will be the number of pounds of cream necessary to standardize the batch to the required ratio. Solution of Problem 9, Based Upon Formula 8 : (NR)— K] L O G— (JR) Problems Before Condensing 197 Problem 9, Example 11. Pounds Per Cent Products Fat S. N. F. T. S. Skim-milk 10,000 .20 26.38 7.80 8.63 6.44 17.70 8.83 Cream 32.82 Composition desired after condensing 25.50 Desired ratio between S. N. F. and fat is 1 to .4407. Solution of Problem 9, Example 11, Based Upon Rule 6: (1.) To calculate the available fat in the cream. 6.44 X .4407 = 2.84, per cent of fat required to equalize the S. N. F. in the cream. 26.38 — 2.84 = 23.54, per cent of fat in the cream available for standardizing. (2.) To calculate the pounds of fat short. 8.63 X .4407 = 3.80, per cent of fat required. 3.80 — .20 = 3.60, per cent of fat short. 10000X.036 = 360, pounds of fat short. (3.) To calculate the pounds of cream required. 360-=-.2354=1530, pounds of cream required. Solution of Problem 9, Example 11, Based Upon Formula 8: [(.0863 X .4407) — .0020] X 10,000 ^ = .2638-(.0644X.4407) = ^^^^'^^ Proof of Problem 9, Example 11 : Products Pounds Pounds Per Cent Fat S. N. F. T. S. Fat S. N. F. T. S. Skim-milk Cream 10,000 1,530.33 11,530.33 20.00 403.74 423.74 863 98.48 961.48 883 502.22 1385.22 .20 26.38 3.675 8.63 6.44 8.33 8.83 32.82 Standardized product 12.00 198 Standardizing Evaporated Milk Ratio of 1 S. N. F. to .4407 fat obtained in product after stand- ardizing. STANDARDIZING EVAPORATED MILK BEFORE CONDENSING. Problem 10. How to Calculate the Weight of Cream to Add, Knowing the Weight of the Whole Milk and the Skim-milk onj Hand, and the Percentages of Fat and Solids Not Fat of All Three Products. Solution of Problem 10, Based Upon Rule 7 : (1.) If the ratio between the percentage of fat and the S. N. F. in the fresh milk is less than the required ratio, standardize the fresh milk with the skim-milk, using Rule 4. Deduct the weight of the skim-milk required to standardize the fresh milk from the total weight of skim-milk on hand. (2.) If the ratio between the percentage of fat and S. N. F. in the fresh milk is less than the required ratio, standardize the fresh milk with cream, using Rule 5. (3.) Now standardize the skim-milk remaining under 1, or all the skim-milk on hand, as in the case under number 2, using Rule 5 to arrive at amount of cream necessary to add in either case. Make the necessary calculations to get proper weights under the double standardization. Solution of Problem 10, Based Upon the Use of Formulas as Indi- cated : (1.) To calculate the pounds of cream to add to the whole milk. Use Formula 7, page 195. (2.) To calculate the pounds of cream to add to the skim-milk. Use Formula 8, page 196. Problem 10, Example 12: Products Pounds Per Cent Fat S. N. F. T. S. Whole Milk 10,000 75 3.58 .16 28.38 8.40 8.47 6.44 11 98 Skim-milk 8 63 Cream 34 82 Pesired ratio of S. N. F, to fat is 1 to .4407, Probi^Ems Bf;pore Condensing 199 Solution of Problem 10, Example 12, Based Upon Rule 7 : A. (1.) To calculate the available fat in the cream. 6.44 X .4407 = 2.84, per cent of fat required to equalize the S. N. F. in the cream. 26.38 — 2.84 == 23.54, per cent of fat available for standardiz- ing. (2.) To calculate the pounds of fat short. 8.40 X .4407 = 3.70, per cent of fat required. 3.70 — 3.58 = .12, per cent fat short. 10000 X .0012 = 12, pounds of fat short. (3.) To calculate the pounds of cream required. 12-^.2354=51.75, the pounds of cream required to standardize the whole milk. Should the whole milk require skim-milk instead of cream, use Rule 4, and subtract the pounds of skim-milk required from the total pounds of skim-milk and then standardize the balance of the skim-milk, using Rule 5. B. Calculating available fat in the cream. (1.) To calculate the available fat in the cream. Same as under A (1) above. It equals 23.54%. (2.) To calculate pounds fat short. 8.47 X .4407 = 3.73, per cent of fat required. 3.73 — .16 = 3.57, per cent of fat short. 75 X .0357 = 2.68, pounds of fat short. (3.) To calculate the pounds of cream required. 2.68-f-. 2354=11.4, the pounds of cream required to standardize the skim-milk. C. Adding together answers obtained under A and B=51.75 plus 11.43 = 63.18 pounds cream required to standardize the entire batch. Solution of Problem 10, Example 12, based upon Formulas 7 and 8. (1.) To calculate the pounds of cream to add to the whole milk. 200 = Standardizing Evaporated Milk (.0840 X .4407) — .0358] X 10,000 .2638— (.0644 X .4407) 51.75 (2.) To calculate the pounds of cream to add to the skim- milk. [(.0847X.4407)— .0016175 O — - - - — 114'^ .2638— (.0644 X. 4407) ~ 51.75 -f 11.43 = 63.18, or total pounds of cream required. Proof of Problem 10, Example 12 : Products Pounds Pounds Per Cent Fat S. N. F. T. S. Fat S. N. F. T. S. Whole milk Skim-milk Cream Standardized product 10,000 75 63.18 10,138.18 358 .12 16.64 374.76 840 6.35 4.20 850.55 1198 6.47 20.84 1225.31 3.58 .16 26.38 3.69 8.40 8.47 6.44 8.38 11.98 8.63 32.82 12.07 Ratio of S. N. F. to fat obtained is 1 to .4407. STANDARDIZING EVAPORATED MILK BEFORE CONDENSING. Problem 11 : How to Calculate the Pounds of Butter to Add. Butter can frequently be used to good advantage in standardiz- ing evaporated milk. Several methods of calculation are possible, but only the one that gives the desired result in the smallest num- ber of calculations is given herewith. Solution of Problem 11, based upon Rule 8 : (1.) Multiply the percentage of S. N. F. in the fresh milk by the ratio between the S. N. F. and the fat in the product desired. Subtract from this the percentage of fat in the fresh milk. Mul- tiply the remainder by the pounds of the fresh milk in the batch. Divide the product by the percentage of fat in the butter, which will give the answer, or the pounds of butter to be added to the entire batch. Problems After Condensing 201 Solution of Problem 11, Example 13 : Products Pounds Per Cent Fat S. N. F. T. S. Milk 10,000 3.58 80.00 7.80 8.40 11.98 Butter Composition desired after condensing 17.70 25.50 Desired ratio of S. N. F. to fat is 1 to .4407. Solution of Problem 11, Example 13, based upon Rule 8: (1.) To calculate the pounds of butter required. 8.40 X .4407 = 3.70, per cent of fat required to equalize the S. N. F. in the whole milk. 3.70— 3.58=.12, per cent of fat short. 10000X.0012=12.0, pounds of fat short. 12.0-:- 80=15, pounds of butter required. Solution of Problem 11, Example 13, based upon Formula 8: (.0840X. 4407)— .0358] 10000 P^r= .80 =il5 Proof of Problem 11, Example 13: Products Pounds Pounds Per Cent Fat S. N. F. T. S. Fat S. N. F. T. S. MUk Butter 10,000 15.23 10,015.23 358 12.18 370.18 840 840 1198 12.18 1210.18 3.58 80.00 3.69 8.40 11.98 Standardized product 8.38 12.08 Ratio 1 S. N. F. to .4407 fat obtained in product after stand- ardizing. 202 Standardizing Evaporate;d Milk STANDARDIZING EVAPORATED MILK REFORE CONDENSING. Problem 12: How to Calculate the Pounds of Cream or Skim- milk to Use, when Mixing Together Fresh Milk and Bulk Condensed Whole Milk. Solution of Problem 12, based upon Rule 9: (1.) Calculate the average fat and S. N. F. test of the mixed fresh milk and bulk condensed milk. Get ratio of fat to S. N. F. in the mixed milk. (2.) If skim-milk is required, calculate the amount necessary to add to the mixture by means of Rule 4. (3.) If cream is required, calculate the amount necessary to add to the mixture by means of Rule 5. Solution of Problem 12, based upon Formula 9 : (1.) To calculate the percentage of fat in the batch after mixing together the whole milk and the bulk condensed whole milk. ^, ^ (PF) + (D^K^) P + D2 (2.) To calculate the percentage of T. S. in the batch, after mixing together the whole milk and the bulk condensed whole milk. Q,^ (PT) + (D^D) P + D (3.) If skim-milk is required calculate according to Formula 6, page 193. (4.) If cream is required, calculate according to Formula 7, page 195. Problem 12, Example 14: Products Pounds Per Cent Fat S. N. F. T. S. Milk 10,000 872 3.58 10.73 26.38 7.80 8.41 25.27 6.44 17.70 11.99 Bulk condensed milk Cream 36.00 32.82 Composition desired after condensing 25.50 Desired ratio of solids not fat to fat is 1 to .4407. ProbIvE;ms After Condensing Solution of Problem 12, Example 14, based upon Rule 9 : 203 (1.) To calculate the average fat and T. S. tests of the mixed fresh milk and bulk condensed milk. Products Total Pounds Fat T. S. Per Cent Pounds Per Cent Pounds Whole milk Bulk condensed whole milk Mixed milk 10,000 872 10,872 3.58 10.73 4.15 358.00 93.60 451.60 11.99 36.00 13.91 1199.00 313.92 1512.92 (2.) To calculate the pounds of cream required follow solu- tion of Problem 8, Example 10, based upon Rule 5, page 194. The answer will be 68.18 or the pounds of cream necessary to add. Should the mixed milk require skim-milk instead of cream, follow the solution of Problem 7, Example 9, based upon Rule 4, page 192. Solution of Problem 12, Example 14, based upon Formula 9 : (1.) To calculate the percentage of fat in the batch after mixing together the whole milk and the bulk condensed whole milk. S^ = (10000X.0358) + (872X.1073) 4.15 10000+872 (2.) To calculate the percentage of T. S. in the batch after mixing together the whole milk and the bulk condensed whole milk. 0^ = (IQQQO X -1199) + (872 X .36) ^ ^^ ^^ 10000 + 872 (3.) To calculate the pounds of cream required, follow the solution of Problem 8, Example 10, based upon Formula 7, page 195. The answer will be 68.18, or the pounds of cream necessary to add. Should the mixture require skim-milk instead of cream, follow the solution of Problem 7, Example 9, based upon Formula 6, page 193. 204 Standardizing Evaporated Milk Proof of Problem 12, Example 14: Products Pounds Pounds Per Cent Fat S. N. F. T. S. Fat S. N. F. T. S. Milk 10,000 872 68.18 10,940.18 358.00 93.6 17.98 469.58 841 . 00 220 . 22 4.20 1065.42 1199.00 313.82 22.18 1535.00 3.58 10.73 26.38 4.29 8.41 25.27 6.44 9.73 11.99 Bulk cond. milk . . Cream 36.00 32.82 Standardized product 14.02 Ratio of 1 S. N. F. to .4407 fat obtained in product after stand- ardizing. STANDARDIZING EVAPORATED MILK BEFORE CONDENSING. Problem 13: How to Calculate When Adding Water Only. Ascertain from the test of the condensed product the ratio between the percentage of S. N. F. and the percentage of fat. If the ratio is the same as in the standard, standardize with water only. In case the ratio between the S. N. F. and the fat is differ- ent than the desired ratio, and if it should be possible or prac- ticable to standardize with water only, standardize down to the lowest constituent that may happen to govern — that is, the fat or the S. N. F. If this is not done, the resulting product will be low in either fat or S. N. F. Two solutions of this problem are given. Solution of Problem 13, based upon Rule 10 : (1.) Subtract the percentage of T. S. desired from the per- centage of T. S. in the milk that is to be standardized. Divide the remainder by the percentage of T. S. desired. Multiply the answer by the pounds of milk in the batch. The answer will be the pounds of water required. The above coefficient of overcondensation can be ascertained directly by referring to Table 31, which gives this value upon the double basis of 7.80 per cent of fat and 25.50 per cent of T. S. and 8.00 per cent of fat and 26.15 per cent of T. S. When Table 31 is available, this makes the simplest method of calculating the amount of water required. Problems Before Condensing Solution of Problem 13, based upon Formula 10: 205 W Problem 13, Example 15: C D^ Products Pounds Per Cent Fat S. N. F. T. S. Evaporated milk Composition desired 4644 8.106 7.80 18.40 17.70 26.506 25.500 Solution of Problem 13, Example 15, based upon Rule 10 : 26.50 — 25.50= 1.00, per cent of T. S. in excess. 1.00 -:- 25.50 =: ,0392, coefficient of overcondensation. 4644 X .0392 = 182, pounds of water required. Solution of Problem 12, Example 15, based upon Formula 10 : W = /26.50 - 25.50 X^^^^ \ 25.50 / 182 Solution of Problem 13, based upon Rule 11 : (1.) Subtract the percentage of fat desired from the percent- age of fat in the batch that is to be standardized. Multiply the pounds of milk in the batch by the remainder. Divide the prod- uct by the percentage of fat desired. The answer will be the pounds of water required to standardize the batch. By this method the T. S. can be used as a basis for making the calculations as well as the fat. This is the simpler of the two methods, unless in the case of the preceding method the factor of overcondensation can be obtained directly from a table which can be especially prepared to cover any standard that might be desired, and covering a wide range of tests. Solution of Problem 13, based upon Formula 11: A Solution of Problem 13, Example 15, based upon Rule 11 : 8.106 — 7.80 ^= .306, per cent of fat in excess. 206 Standardizing Evaporated Milk 4644X .00306=14.21, pounds of fat in excess. 14.21h-.0780=:182, pounds of water required. Solution of Problem 13, Example 15, based upon Formula II : (.08106— .078) 4644 W .078 r=182 Proof of Problem 13, Example 15, covering both Rules 10 and 11 : Products Pounds Pounds Per Cent Fat S. N. F. T. S. Fat S. N. F. T. S. Evaporated milk.. Water 4644 182 4826 376.4 854.4 1230.8 8.106 18.40 26.50 Standardized product 376.4 854.4 1230.8 7.80 17.70 25.50 No factor of safety was allowed in the above problem. It is recommended that a margin be allowed of .05 per cent upon fat and .20 per cent upon T. S., where the product is standardized upon the basis of both the fat and the S. N. F. The same margin is recommended where the standardization is based upon one con- stituent only. STANDARDIZING EVAPORATED MILK BEFORE CONDENSING. Problem 14 : How to Calculate When Both Condensed Skim-milk and Water are Required for Standardizing. Solution of Problem 14, based upon Rule 12 : (1.) Subtract the percentage of fat desired from the percent- age of fat in the batch before standardizing. Multiply the re- mainder by the pounds of milk in the batch. Divide the product by the percentage of fat desired. Call answer A, or the total pounds that the batch is short. (2.) Divide the percentage of fat in the batch to be standard- ized by the ratio between the T. S. and the fat, in the product de- sired. Subtract from the answer the percentage of T. S. in the batch to be standardized. Multiply the remainder by the pounds in the batch before standardizing. Divide the product by the per- centage of T. S. in the skim-milk to be used for standardizing. Problems Before Condensing 207 Call the answer B, or the pounds of skim-milk required. Sub- tract B from A. Call the remainder C, or the pounds of water re- quired. (3.) Add A and C to the pounds in the batch before stand- ardizing. The sum will be the total pounds in the batch after standardizing with both water and skim-milk. Solution of Problem 14, based upon Formula 12: (1.) To calculate the pounds of condensed skim-milk re- quired. U = (i-^0 D^ T- (2.) To calculate the pounds of water required. ■(K^— A) D^ W = r(K -A) PI — L^ Problem 14, Example 16: Products Pounds Per Cent Fat S. N. F. T.S. Evaporated milk Condensed skim-milk .... 10000 8.00 18.00 26.00 25.50 Water Composition desired 7.80 17.70 25.50 Solution of Problem 14, Example 16, based upon Rule 12 : (1.) To calculate the pounds that the batch is short. 8.00 — 7.80 r= .20, per cent of fat in excess. 10000 X .0020 = 20, pounds of fat in excess. 20-^.0780= 256, total pounds that the batch is short. (2.) To calculate the pounds of condensed skim-milk and pounds water necessary to add. 8.00 -f- .3059 = 26.15, per cent of total solids necessary to equalize the fat in the batch. 26.15 — 26.00 = .15, per cent of total solids required to be added to equalize the fat in the batch. 10000 X .0015 =: 15, pounds of total solids required. 208 Standardizing Evaporated Milk 15 ^-.255 = 59, pounds of condensed skim-milk required. 256 — 59 = 197, pounds of water required. (3.) Material in batch after standardizing. 59 pounds of condensed skim-milk. 197 pounds of water. 10,000 pounds before standardizing. 10,256 pounds total after standardizing. Solution of Problem 14, Example 16, based upon Formula 12 : (1.) To calculate the pounds of condensed skim-milk re- quired. U = ( •^^^^ — .2600^ X 10000 .3059 / .2550 = 59.6 [2.) To calculate the pounds of water required. (8.00 — 7.80) X 10000 w = I 7.80 1 59 = 196.8 Proof of Problem 14, Example 16: Products Pounds Pounds Per Cent Fat S .N. F. T. S. Fat S. N. F. T. S. Evaporated milk.. Condensed skim- milk 10,000.0 59.6 197.0 10,256.6 800 1800 15 2600 15 8.00 18.00 25.50 26.00 25.50 Water Standardized product 800 1815 2615 7.80 17.70 25.50 No factor of safety allowed in the above problem. STANDARDIZING EVAPORATED MILK AFTER CONDENSING. Problem 15 : How to Calculate When Both Cream and Water are Required for Standardizing. Solution of Problem 15, based upon Rule 13 : (1.) Subtract the percentage of S. N. F. desired from the percentage of S. N. F. in the batch before standardizing. Multi- Problems After Condensing 209 ply the remainder by the pounds of milk in the batch. Divide the product by the percentage of S. N. F. desired. Call the answer A, or the pounds that the batch is short. (2.) Multiply the percentage of S, N. F. in the batch by the ratio between the S. N. F. and the fat in the product desired. Sub- tract from the answer the percentage of fat in the batch to be standardized. Multiply the remainder by the pounds in the batch before standardizing. Divide the product by the percentage of fat in the cream to be used for standardizing. Call the answer B, or the pounds of cream required. Subtract B from A. Call the answer C, or the pounds of water required. (3.) Add A and C to the pounds in the batch before standard- izing. The sum of the three values will be the total pounds in the batch after standardizing with both water and cream. Solution of Problem 15, based upon Formula 13 : (1.) To calculate the pounds of cream required: = [ (B^XR)— K^] XD ^ G (2.) To calculate the pounds of water required. (Bi — B) XD^ Problem 15, Example 16: B O Products Pounds Per Cent Fat S. N. F. T. S. Evaporated milk Cream 10,000 7.00 40.00 20.00 27.00 Water Composition desired 7.80 17.70 25.50 Solution to Problem 15, Example 16, based upon Rule 13; (1.) To calculate the pounds that the batch is short. 20.00 — 17.7 = 2.30, per cent of S. N. F. in excess. 10000 X .023 = 230, pounds of S. N. F. in excess. 230 -f- .177 = 1299, pounds that the batch is short. I 210 Standardizing Evaporated Milk (2.) To calculate the pounds of cream and water necessary. 20.00 X .4407 = 8.81, per cent of fat necessary to equalize the S. N. F. in the unstandardized batch. 8.81 — 7.00 ^ 1.81, per cent of fat required to equalize the S. N. F. in the batch. 10000 X. 0181=181, pounds of fat required. 181 -^- .40 = 453, pounds of 407p cream required. 1299 — 453 = 846, pounds of water required. (3.) Material in batch after standardizing. 458 pounds of 40% cream. 846 pounds of water. 10000 pounds before standardizing. J1299 pounds total in batch after standardizing. Solution of Problem 15, Example 16, based upon Formula 13: (1.) To calculate the pounds of cream required. [ (.20 X .4407) — .07] X 10000 0=: .40 453 (2.) To calculate the pounds of water required. (.20— .1770) X 10000 w = .1770 — 453 = 846 Proof of Problem 15, Example 16: Products Pounds Pounds Per Cent Fat S. N. F. T. S. Fat S. N. F. T. S. Evaporated milk. . Cream .... 10,000 453 846 11,299 700 181.4 2000 2700 181 7.00 40.00 20.00 27.00 Water Standardized product 881.4 2000 2881 7.80 17.70 25.50 No factor of safety allowed in the above calculation. Also the S. N. F. in the cream was disregarded in the calculation. In the above example this would increase the total solids to the extent of about 27 pounds, making the actual total solids 25.65 per cent in- stead of 25.50 per cent as indicated in the proof. pROBLKMs After Condensing 211 STANDARDIZING EVAPORATED MILK AFTER CONDENSING. Problem 16: How to Calculate When Condensed Whole Milk, Condensed Skim-milk and Water Are Required for Standardizing. Solution of Problem 16, based upon Rule 14 : (1.) Call the T. S. in the condensed skim-milk A, or the per- centage of S. N. F. in the condensed skim-milk that is available for standardizing. Subtract the percentage of fat desired from the percentage of fat in the condensed milk. Call the remainder B, or the percentage of fat in the condensed whole milk that is available for standardizing. Subtract the percentage of S. N. F. desired from the percentage of S. N. F. in the condensed whole milk. Call the remainder C, or the percentage of S. N. F. in the condensed whole milk available for standardizing. (2.) Divide the percentage of fat in the batch by the ratio between the S. N. F. and the fat in the product desired. Subtract from the answer the percentage of S. N. F. in the batch and mul- tiply the remainder by the pounds of milk in the batch. Call an- swer T>, or the pounds of S. N. F. short. Subtract the S. N. F. that the batch should contain from the S. N. F. in the condensed whole milk. Divide D by the remainder. Call the answer E, or the pounds of condensed whole milk required. (3.) Multiply E by B. Divide the product by the ratio be- tween the S. N. F. and fat in the product desired. Divide the answer by A. Call the answer F, or the pounds of condensed skim-milk required to equalize the excess fat in the condensed whole milk. (4.) Multiply the pounds of milk in the batch before stand- prdizing, by the percentage of S. N. F. in the batch. Call the an- swer G, or the pounds S. N. F. in the batch. Multiply E and F by the S. N. F. test of each respectively, and add the two results. Call the answer H. Call the sum of G and H, I or the pounds of S. N. F. in the entire batch, after standardizing. Add to the pounds in the batch before standardizing, the sum of E and F. Call the an- swer J. Divide the answer into I. Call the answer K, or the per- centage of S. N. F. in the batch after standardizing with con- densed whole milk, and condensed skim-milk. Subtract from K 212 Standardizing Evaporated Milk the percentage of S. N, F. in the product desired. Multiply the remainder by J, and divide the product by the percentage of S. N. F. desired. Call the answer K, or the pounds of water required. (5.) Add to the pounds of whole milk before standardizing, the sum of E, plus F, plus J. The answer will be the total pounds in the batch after standardizing. Solution of Problem 16, based upon Formula 14 : (1.) To calculate the pounds of condensed whole milk re- quired. [^■■] — Bi I D^ M— f — (f) (2.) To calculate the pounds of condensed skim-milk re- quired. U = {^^^^) Q (3.) To calculate the percentage of S. N. F. in the batch after adding the condensed whole and skim-milks. Note: S- now rep- resents the percentage of S. N. F. in the mixture. D^ + D- + L^ (4.) To calculate the pounds of water required. ^^.^ (S^-A) X (D^ + D^ + L^) Problems After Condensing Problem 16, Example 17: 213 Products Pounds Per Cent Fat S. N. F. T. S. Evaporated milk Condensed whole milk .... 10,000 8.00 t 10.50 17.00 25.50 25.50 25.00 36.00 Condensed skim-milk .... Water Composition desired 7.80 17.70 25.50 Solution of Problem 16, Example 17, based upon Rule 14: (1.) To calculate in the above two products the percentage of fat and the percentage of S. N. F. available for standardizing. 25.50 = S. N. F. (the fat is disregarded), or total solids in con- densed skim-milk available for standardizing. 10.50 — 7.80 = 2.70, per cent of fat in condensed whole milk available for standardizing. 25.50 — 17.70 =: 7.80, per cent S. N. F. in condensed whole milk available for standardizing. (2.) To calculate the pounds of condensed whole milk re- quired. 8.00-^.4407 = 18.15, per cent of S. N. F. that the evaporated milk should have. 18.15 — 17.00 = 1.153, per cent of S. N. F. short. .0115X10000=115.3 pounds S. N. F. short. 25.50 — 18.15 = 7.35, per cent of S. N. F. available for stand- ardizing in condensed milk. 115.3-f-.0735 = 1568 pounds condensed whole milk required to provide the S. N. F. short. (3.) To calculate the pounds of condensed skim-milk re- quired. 1568 X. 027=43, pounds of fat 'in excess over amount required in the condensed whole milk. 43 -^ .4407 = 96, pounds of S. N. F. required to equalize the excess of fat in the condensed whole milk. 214 Standardizing Milk and Cream 96-f-.255=:377, pounds of condensed skim-milk required to equalize the excess fat in the condensed whole milk. (4.) To calculate the pounds of water required. 10000 X .17=1700, pounds of S. N. F. in batch before stand- ardizing. (1568 + 377) X .255 = 496, pounds of S. N. F. in condensed whole milk and condensed skim-milk required. 1700 -f 496 = 2196, pounds of S. N. F. in batch after adding con- densed whole milk and condensed skim-milk. 10000 + 1568 4- 377 = 11945, total pounds in batch after adding condensed whole milk and condensed skim-milk. 2196 ^ 11945 = 18.38, per cent S. N. F. in batch after adding condensed whole milk and condensed skim-milk. 18.38 — 17.70 = .68, per cent S. N. F. in excess after adding con- densed whole milk and condensed skim-milk. 11945 X .0068 = 82, pounds S. N. F. in excess. 82 -^ .1770 := 463, pounds of water required. (5.) Material in batch after standardizing^. 1568 pounds condensed whole milk. 377 pounds condensed skim-milk. 10000 pounds before standardizing. 463 pounds water. 12408 pounds total after standardizing. Solution of Problem 16, Example 17, based upon Formula 14: (1.) To calculate the pounds of condensed whole milk re- quired. II44077 J J \ .4407 / X 10000 D = '-^ ^ --5- = 1568. .2550 — j (2.) To calculate the pounds of condensed skim-milk re- quired to standardize the excess of fat in the whole milk. /.105— .078)X1568.6\ \ 4407 J Problems After Condensing 215 (3.) To calculate the percentage of S. N. F. in the batch after adding the condensed whole and skim-milk. (10000X.17) + (1568X.2550) + (377X.2550) 10000 + 1568 + 377 " (4.) To calculate the pounds of water required. (.1838— .177) X (10000+1568+377) W .177 =463 Proof of Problem 16, Example 17: Pounds Pounds Per Cent Products Fat S. N. F. T. S. Fat S. N. F. T. S. Evaporated milk. . Condensed whole milk 10,000 1568 377 463 12,408 800 164.7 1700 400 96 2500 564 96 8.00 10.50 17.00 25.50 25.50 25.00 36.00 Condensed skim- milk 25.50 Water Standardized product 964.7 2196 3160 7.80 17.70 25.50 STANDARDIZING EVAPORATED MILK AFTER CONDENSING. Problem 17: How to Calculate When Both Condensed Whole Milk and Cream Are Required for Standardizing : Solution of Problem 17, Based Upon Rule 15 : (1.) Subtract the percentage of fat desired from the percentage of fat in the cream. Call the an.swer A, or the percentage of fat in the cream available for standardizing. Subtract the percentage of S. N. F. in the cream from the percentage of S. N. F. desired. Call the answer B, or the percentage of S. N. F. short in the cream, un- der that desired. Subtract the percentage of fat desired from the percentage of fat in the condensed whole milk. Call the answer C, or the percentage of fat in the condensed whole milk available for standardizing. Subtract the percentage of S. N. F. desired from the percentage of S. N. F. in the condensed whole milk. Call the remainder D, or the percentage of S. N. F. in the condensed whole milk available for standardizing. 216 Standardizing Milk and CrEam (2.) Subtract the percentage of fat in the batch from the per- centage of fat desired. Call the remainder E, or the percentage of fat short. Multiply the pounds of milk in the batch by E. Call the product F, or the pounds of fat short. Subtract the percen- tage of S. N. F. in the batch from the percentage of S. N. F. de- sired. Call the remainder G, or the percentage of S. N. F. short. Multiply the pounds milk in the batch by G. Call the product H, or the pounds of S. N. F. short. (3.) Divide H by the percentage of fat desired. Call the an- swer I, or the pounds of condensed whole milk required to provide the S. N. F. short in the batch. (4.) Multiply I by C. Call the product J, or the pounds fat available in the condensed whole milk added. Subtract J from E. Call the answer K, or the pounds fat to be provided by cream. Divide K by A. Call the answer L, or the pounds of cream re- quired to provide the fat short. (5.) Multiply L by B. Call the product M, or the pounds of S. N. F. short in the cream. Divide M by D. Call the answer N, or the pounds of condensed whole milk necessary to provide the S. N. F. required to standardize the cream added. (6.) Add to the pounds of milk in the batch before standard- izing the sum of I, L and N. The answer will be the total pounds in batch after standardizing. Solution of Problem 17, Based Upon Formula 15 : (1.) To calculate the pounds of condensed whole milk re- quired to provide the S. N. F. short in the evaporated milk. ^.^^ [(B-B^)D^ ] A (2.) (To calculate the pounds of cream required to provide the fat short in the evaporated milk. Q^ [(A-K^) D^]-[(K-A) D--] G — A (3.) To calculate the pounds of condensed whole milk re- quired to provide the S. N. F. short in the cream. D2^ (B — J)0 A Note: The sum of D- part (1) and D^ part (2) of the formula equals the total number of pounds of condensed whole milk used. pROBi^KMS After Condensing Problem 17, Example 18 : 217 Products Pounds Per Cent Fat S. N. F. T. S. Evaporated milk Condensed whole milk .... 10,000 7.36 10.50 40.00 7.80 17.46 25.50 5.00 17.70 24.82 36.00 Cream 45.00 Composition desired 25.50 Solution of Problem 17, Example 18, based upon Rule 15 : (1.) To calculate in the above two products the percentages of fat and S. N. F. available for standardizing. 40 — 7.8 j=. 32.2, per cent, of fat in cream available for stand- ardizing. 17.7 — 6.0 = 11.7, per cent of S. N. F. short in cream. 10.50 — 7.80 ^ 2.70, per cent of fat in condensed whole milk available for standardizing. 25.50 — 17.70= 7.80, per cent of S.N. F. in condensed whole milk available for standardizing. (2.) To calculate pounds of fat and S. N. F. short. 7.80 — 7.36 = .44, per cent of fat short. 10000 X. 44= 44, pounds of fat short. 17.70 — 17.46 = .24, per cent of S. N. F. short. 10000 X. 0024=24, pounds of S .N. F. short. (3.) To calculate the pounds of condensed whole milk re- quired to provide S. N. F. short in batch. 24.0-^.078=308, pounds of condensed whole milk required to provide the S. N. F. short in the batch. (4.) To calculate the pounds of cream required: 308 X .027= 8.3, pounds of fat available in condensed whole milk added. 44 — 8.30 = 35.7, pounds of fat to be provided by cream. 35.7-^-.322=;lll, pounds of cream required to provide the fat short. 218 Standardizing M11.K and Cream (5.) To calculate the pounds of condensed whole milk re- quired to equalize the S. N, F. short in the cream added for stand- ardizing. Ill X. 117=13.0, pounds of S. N. F. short in cream. 13.0-^-.078= 167, pounds of condensed whole milk necessary to provide the S. N. F. required to standardize the cream added. (6.) Material in batch after standardizing. 308 pounds of condensed whole milk required by batch. 167 pounds of condensed whole milk required by cream. Ill pounds of cream, 10000 pounds before standardizing. 10586 pounds total after standardizing. Solution of Problem 17, Example 18, Based Upon Formula 15 : (1.) To calculate the pounds of condensed whole milk re- quired to provide the S. N. F. short in the evaporated milk. (.177— .1746) X 10000 ^'= m =^"« (2.) To calculate the pounds of cream required to provide the fat short in the evaporated milk. [ (.078— .0736) XlOOOO] — [ (.1050— .078) X308]_ ^ ^ .40— .078 ~ ^^^ (3.) To calculate the pounds of evaporated whole milk re- quired to provide the S. N. F. short in the cream. (.177— .06)X111 °'= ^JTS ="^ Probi^ems Aft^r Conde:nsing 219 Proof of Problem 17, Example 18: Products Pounds Pounds Per Cent Fat S. N. F. T. S. Fat S. N. F. T. S. Evaporated milk. . Condensed whole milk 10,000 475 111 10,586 736 50 44 830 1746 121 61 1873 2482 171 50 2703 7.36 10.50 40.00 7.83 17.46 25.50 6.00 17.69 24.82 36.00 Cream 46.00 Standardized product 25.52 The surplus fat in the condensed whole milk added to stand- ardize the cream was disregarded in the calculation. This method does not give absolutely correct standardization but the results are within very narrow limits of those desired. CHAPTER XII STANDARDIZING SWEETENED CONDENSED MILK The principles underlying the standardization of sweetened condensed milk are very similar to those underlying the standard- ization of evaporated milk, namely, mixing together fat, milk S. N. F. and in addition sucrose obtained from either cane or beet sugar, in the ratio one to the other that these are to occur in the finished product which it is desired to manufacture. These ratios can be obtained upon any desired composition of product by di- viding the percentage of one constituent into the percentage of another constituent of the standard product. Table 32 contains these ratios in the case of a product testing 8.00 per cent of fat, 20.00 per cent of milk S. N. F. and 44.50 per cent sucrose, and also in the case of sweetened condensed skim-milk. Theoretically it would be possible under certain conditions to standardize sweetened condensed milk after condensing. How- ever, the possibilities for trouble under conditions of this kind are so numerous that it is deemed best not to encourage the practice at the present stage of our knowledge. The practice of standard- izing before condensing is a simple and a logical one, and this will be fully discussed in this chapter. Under the older methods the standardization is, as a rule, crude and inefficient, and concerns itself chiefly with obtaining a prod- uct either of a certain fat or of a certain T. S. test. The method commonly used is to add a certain number of pounds of sugar for every 'one hundred pounds of whole milk that go to make up the batch. Sometimes the ratio of pounds of sugar to pounds of milk is varied with the season of the year, the range being in the case of whole milk, from 18 to 20 pounds. Under this method, the re- sulting product varies greatly both in chemical composition, and in its physical properties. [220] SwEETEiNED Condensed Milk Constants TABLE 32. Constants for Sweetened Condensed Milk. 221 Product from Constants. WlioIe milk. Skim- milk. Percentage fat. Federal standard 8.00 20.00 28.00 3.5000 None Percentage S. N. F. Federal standard 28.00 Percentage T. S. Federal standard 28.00 Ratio percentage fat to percentage milk solids . . . None Ratio percentage fat to T. S. (8.00 per cent fat to 72.5 per cent T. S.) 9.06 None Ratio percentage fat to percentage milk S. N. F . . 2.5000 None Ratio percentage milk S. N. F. to percentage fat . . .4000 None Ratio percentage milk S. N. F. to percentage T. S. 1.4000 None Ratio percentage total milk solids to percentage fat .2857 None Ratio percentage sugar to percentage fat, using 44.50 per cent sugar .1798 None Ratio percentage sugar to percentage total milk solids, using 44.50 per cent sugar .4493 None Ratio percentage sugar to percentage total milk solids, using 42.00 per cent sugar .6667 Under the methods given in this chapter, the aim is to stand- ardize the sweetened condensed milk upon the triple basis of fat, milk S. N, F. and sucrose. This makes possible a product of uni- form chemical composition and physical properties, at all times, other things being equal. SUCCESSIVE STEPS IN STANDARDIZING SWEETENED CON- DENSED MILK. The steps involved in standardizing sweetened condensed milk are as follows : (1.) Obtaining a representative composite sample of the en- tire lot of whole milk which goes to make up the batch ; likewise the skim-milk, cream or other product which might be used in standardizing, (2.) Testing of all the above products involved for both fat, S. N. F. or T, S. by means of the Mojonnier Milk Tester. In the case of the S. N. F. in the cream, it usually suffices to obtain the S. N. F. from Table 22, inasmuch as the amount is not large. 222 Standardizing Sweetened Condensed Milk (3.) Calculating the weight of each product to be used by methods which will follow, in order to make the fat, the milk S. N. F. and the sugar in the initial product of the same ratio as these are to occur in the case of the finished product. (4.) When the initial product has been standardized so that the fat, the milk S. N. F. and the sugar are in the required ratio, the same is to be condensed down to the desired specific gravity to yield a finished product of the test required. In practice, it is well to condense the batch to a little higher concentration than desired, in order to provide the necessary factor of safety. If the concentration of the batch should be less than the required con- centration, it becomes necessary either to recondense part of the batch, or to condense another batch to add to it, provided the facilities are at hand for thoroughly mixing the two batches. It is not recommended at this stage of our knowledge of the sweet- ened condensed milk business to add water to the batch in case it is overcondensed. Under some conditions, it may be possible to add condensed skim-milk, but this is not very often practicable unless this can be added to the milk in the pan instead of to the milk in the mixing tanks after cooling. At the present time the only method that is recommended for correcting improper con- densing is by mixing together the batch that is improperly con- densed with another batch that is condensed in the proper way to correct the error in the case of the first batch. METHOD OF COLLECTING COMPOSITE MILK SAMPLES. No fixed method of sampling is recommended that can be ap- plied to meet all the varying conditions of different plants. This important matter will need careful study in each plant, in order to determine the procedure that will give the most accurate sam- ples. The reader is referred to Chapter VI for complete informa- tion upon this point. METHOD OF TESTING. Use the Mojonnier Tester for making all fat and T. S. deter- minations upon all products used in standardizing. The skim- milk and cream should be tested before the composite sample of the whole milk reaches the laboratory. The S. N. F. in the cream can be obtained from Table 22 as the total amount of the same is Order of OpERAtioNS 223 usually small, so the possibility for error that may result on ac- count of not making actual determinations of S. N. F. is a very negligible one. As it is necessary to complete the fat and T. S. tests of the whole milk while the last forewarmer is being heated and drawn into the pan, these tests should be made as rapidly as possible. A short time before the sample is ready, the tempera- ture of the hot plates and ovens upon the Mojonnier Milk Tester should be regulated ; fat and T. S. dishes cooled and weighed ; clean glassware and a weigh cross prepared for use, and every- thing put in readiness for making the test. By systematizing the successive steps, the time for completing the fat and T. S. tests, including the total time for making the calculations, should not exceed twenty-five or thirty minutes, counting from the time the sample reaches the laboratory. Under some conditions, it may be desirable to give the operator a helper, while making the tests, as this will greatly expedite the operations. ORDER OF OPERATIONS IN STANDARDIZING SWEETENED CON- DENSED MILK REFORE CONDENSING, USING MOJONNIER TESTER. (1.) Test, as far in advance as possible, the cream samples for fat. Obtain the S. N. F. test of the cream from Table 22. If skim-milk, sweetened condensed skim-milk, or sweetened con- densed whole milk are to be used for standardizing, test each of these products for both fat and T. S. as far in advance as pos- sible. (2.) About half an hour before the composite whole milk sam- ple is ready, do everything necessary to begin making the fat and T. S. test of the whole milk. It is recommended that the tests be made in duplicate. If the operator is very careful in his work, a single determination may suffice. (3.) Keep the fat and the T. S. dishes in the respective ovens for five minutes under proper heat, and with the vacuum on. (4.) Transfer the dishes from the ovens to the cooling desic- cators. Keep the water circulating. Weigh the T. S. dish with the cover on, at the end of five minutes ; and the fat dish alone at the end of seven minutes. Record weights and numbers upon the laboratory report. 224 Standardizing Sweetened Condensed Miek (5.) As soon as the composite whole milk sample reaches the laboratory, mix the same thoroughly by pouring back and forth at least six times using two vessels. (6.) Fill the two gram pipette to the mark and transfer the milk to the previously weighed dish, and weigh the dish with the milk immediately. Or, if preferred, the sample in the two gram pipette can be weighed from the weigh cross. (7.) While the operator is weighing the sample, as directed under 6, the second operator pipettes out ten grams into the but- terfat extraction flask. (8.) One operator now prepares the T. S. sample for the T. S. oven, and the second operator the fat sample for the fat oven. Dishes and contents are heated in ovens, cooled in cooling desic- cators and weighed in accordance with the directions. (9.) Calculate the percentage of fat and the percentage of T. S. and transfer the results to the sweetened condensed milk re- port blank. (10.) Calculate the pounds of material to add, using the rule that may apply, selecting the proper one beginning with Rule 16, and ending with Rule 23. The sugar to be used can be ascertained by referring to Table 32. (11.) Test the finished product for fat and T. S. and enter the result upon the sweetened condensed milk report. (12.) Divide the percentage of T. S. by the percentage of fat to get the ratio of fat to T. S. in the finished product. (13.) If the condensation is not otherwise obtained, divide the percentage of T. S. in the finished product by the percentage of T. S. in the initial product, or divide the percentage of fat in the finished product by the percentage of fat in the initial product. (14.) Divide the total pounds of raw products used by the condensation to obtain the pounds in the batch after condensing. Or, obtain the pounds in the batch by weighing the same in a suit- able tank as it comes from the pan; (15.) Calculate the pounds of raw milk products per case, likewise the pounds of sugar per ease. SwEKTENKD MtI.K RrpORT 225 SWEETENED MILK REPORT I BLANK FOR RECORDING THE STANDARDIZING DATA. It is very important to keep a systematic record of all data in connection with the standardization of any given batch. A blank especially designed for this purpose is illustrated under Fig. 69. METHOD OF GETTING WEIGHTS. The person who does the standardizing should be sure that the pounds of whole milk, likewise the pounds of cream and skim-milk used, are correctly re- ported and properly checked. If this part of the work is not prop- erly done, large errors may be introduced in the work. The pounds of fin- ished product should be correctly ascertained. The methods suggested in Chapter XI, for get- ting the weight of the finished batch of evap- orated milk can be applied with a few modifications to sweetened condensed milk. Where possible the weight of each batch as the same is dropped from the pan, should be obtained. HOW TO CALCULATE THE POINT AT WHICH TO STRIKE THE BATCH IN THE PAN. On account of the impossibility of correcting for overconden- sation, as in the case of evaporated milk, the striking point upon sweetened condensed milk requires most careful watching. Ex- act knowledge is necessary as to just what striking point is re- quired to produce a certain concentration of product. Table 35 gives the specific gravity at different temperatures of sweetened condensed milk in which the constituents are in the following ratio : 8.00 per cent of fat, 20.00 per cent of milk S. N, F., 44.50 per cent of sucrose and 72.50 per cent of T. S. The actual composition was 8.05 per cent fat, 20.13 per cent of milk S. N. F. and 73.00 per cent of T. S. "■S" 'Z :e "J^*" s^: .JiR, "^"1 ^sJ ir SiH" "iP (Mo, "■•'— '^ 1 MOOUCn USED "- ^.. .«,. '^S" TvulKlblt """^resjuS?" "-' »MDMTAIHU> i^.». "■- T^,^ ,^^_„ I..^ <«_.>. >._~l._ Mi. «_....«. ':sr;.'^— " 'sti-s .»(...»■ ... z-z ^B iir^ %58«r W -"."•" r-.-- "rt flN Twllt. .!]..-....«,. Ml««m«. »»d-CI .^..1 '"tl.iSlrt.^V"" ' Brt„ «'«tartttlM --atrsrsiK. "iS-SKiS'-uSi 's^.t.'s;:— -"H A..., «.J«.^..»., SS£Si'™^"Kli ^sr.'j.risr- o.t , o> Fig-. 69. Blank Beport for Sweetened Condensed Milk. 226 Standardizing Sweetened Condensed Milk TABLE 33, Specific giavity at various temperatures of sweetened condensed whole milk testing 8.00 per cent of fat; 20.00 per cent of milk S. N. F., and 72.50 per cent of T. S. Sample furnished by Carnation Milk Products Co. Tests made by J. A. Cross and H. J. Liedel. Temper- ature °F. Specific Gravity Degrees Baume Degrees Twaddell Temper- ature °F. Specific Gravity Degrees Baume Degrees Twaddell 40 1.3157 34.8 63.14 110 1.2881 32.4 57.62 60 1.3065 34.0 61.30 120 1.2853 32.2 57.06 80 1.2986 33.3 59.72 130 1.2818 31.9 56.36 100 1.2918 32.8 58.36 140 1 . 2789 31.6 55.78 Based upon the foregoing table, the unit temperature and spe- cific gravity relation in sweetened condensed whole milk of the test indicated is as shown in Table 34. TABLE 34. Unit relation of temperature to specific gravity in sweetened condensed whole milk testing 8.00 per cent fat; 20.00 per cent M. S. N. F., and 72.50 per cent T. S. Temperature Range Decrease in specific gravity (or vice versa F. increase in temperature. ) , for each degree Specific Gravity Baume Twaddell 40° to 80° F .00043 .038 .085 80° to 110° F . 00035 .030 .070 110° to 140° F .00030 .027 .060 The above relation can be used to advantage in reducing spe- cific gravity to a definite temperature, when striking the batch at the pan. Example : — Baume reading at 135° F. is 31.75. What is the Baume reading at 130° F.? 135 — 130=5, degrees F. over standard desired. .027 X 5 =.135, degree Baume to be added to reading. 31.75+.135=31.9, the 135° F. Baume reading reduced to 130° F. Specific Gravity and Composition 227 RELATION BETWEEN SPECIFIC GRAVITY AND COMPOSITION IN SWEETENED CONDENSED WHOLE MILK. Whenever it may be necessary to change the composition of a given batch of svreetened condensed milk, it is important to knov^ the relation between specific gravity and composition so that the striking point of additional batches may be so altered as to yield a mixed product of the desired test. Table 35 gives this relation in the case of a product in which the constituents are in the ratio 8.00 per cent fat, 20.00 per cent of milk S. N. F., 44.50 per cent of sucrose and 72.50 per cent of T. S. TABLE 35. Relation Between Specific Gravity and Composition in Sweetened Condensed Whole Milk. i Composition At 60° F. At 100° F. At 120° F. At 140° F. si p. t- coo 01 e 3 03 030 01 e 3 01 m •a — 'p p. u. OQO i 3 0! m ■0 — fOO a B 3 « 113 73.00 T. S. 20.12 M.S.N.F. 8.05 fat 1.3087 34.2 61.74 1.2947 33.0 58.94 1.2883 32.5 57.76 1.2819 31.9 56.38 72.50 T. S. 20.00 M.S.N.F. 8.00 fat 1.3065 34.0 61.30 1.2918 32.8 58.32 1.2853 32.2 57.06 1.2789 31.6 55.78 71.25 T. S. 19.66 M.S.N.F. 7.86 fat 1.3044 33.8 60.88 1.2888 32.5 57.76 1.2826 31.9 56.52 1.2753 31.3 55.06 70.00 T. S. 19.33 M.S.N.F. 7.73 fat 1.2988 33.4 59.76 1.2842 32.1 56.84 1.2778 31.5 55.56 1.2699 30.8 53.98 68.75 T. S. 19.06 M.S.N.F. 7.59 fat 1.2923 32.8 58.46 1.2787 31.6 55.74 1.2724 31.0 54.48 1.2651 30.4 53.02 67.50 T. S. 18.63 M.S.N.F. 7.45 fat 1.2857 32.2 57.14 1.2728 31.1 54.56 1.2665 30.5 53.30 1.2599 29.9 51.99 66.25 T. S. 18.28 M.S.N.F. 7.31 fat 1.2793 31.7 55.86 1.2673 30.6 53.46 1.2601 29.9 52.02 1.2541 29.4 50.82 From the above table it is ascertained that a difference of .10 degrees Baume is equal to about .27 per cent of T. S. in the case of sweetened condensed whole milk of the above composition. 228 Standardizing SwfiETiiNED Condensed Milk This information is applied in practice as shown by the follow- ing example : The condensed milk in the standardizing tank weighs 35,100 pounds and tests 8.22 per cent of fat and 74.50 per KEY TO FIG. 70 Curve 1 2 3 4 5 6 7 Fat per cent . . . 7.45 7.55 7.72 7. 86 7.94 8.00 8.05 Sugar per cent . 41.43 42.23 42.96 43.74 44.20 44.50 44.83 Total Solids per cent 67.50 68.75 70.00 71.25 72.00 72.50 73.00 V/rr/N DEGREE5 BAUME Piff. 70. Relation between temperature, specific gravity and composition in the case of sweetened condensed milk in which the ratio bei'ween M. S. TX. F. an4 fat is as 1 to .40, Results obtained by J. A. Cross and K. J. I^iedel, Specific Gravity and Composition 229 cent of T. S. The test desired is 8.11 per cent of fat and 73.50 per cent of T. S. 74.50 — 73.50 = 1.00 per cent of T. S. in excess of that required. 35100 X 1.00 per cent = 351, or pounds of T. S. that are overcondensed. The milk in the last pan batch available should yield normally about 5700 pounds of condensed milk testing 73.50 per cent of T. S., and 34.4° Baume at 140° F. Since .10 degree Baume varies the T. S. test .28 per cent, upon 5700 pounds the variation would be equivalent to 15.96 pounds of T. S. per .10 degree Baume. Dividing 351 by 15.96 equals 22.0, or the number of .10 degree Baume necessary to deduct from the normal striking point of the last pan batch, namely 34.4"^ Baume. Therefore 34.4 — 2.20 = 32.2° Baume, or the striking point upon the last batch, necessary to make the correction desired. The graph under Fig. 70 gives the composition, temperature and specific gravity in Baume degrees, in the case of sweetened condensed whole milk of the composition named above. This graph can be used within its limits to find the composition at any given Baume test, and temperature ; or vice versa, the Baume test at any given composition and temperature. RELATION BETWEEN SPECIFIC GRAVITY AND COMPOSITION IN SWEETENED CONDENSED SKIM-MILK. The above relation, expressed in several ways, is given in Tables 36 and 37, and by graph under Fig. 71. The values given are based upon careful and accurate pycnometer determinations, under exact temperature control. TABLE 36. Specific gravity sweetened condensed skim-milk testing .50 per cent fat, 27.50 per cent M. S. N. F., and 70.00 per cent T. S. Tests made by J. A. Cross and H. J. Liedel. Temper- ature °F. Specific Gravity Degrees Baume Degrees Twaddell Temper- ature °F. Specific Gravity Degrees Baume Degrees Twaddell 40 1.3483 .37.5 69.66 110 1 . 3306 .36.0 66.12 60 1 . 3436 37.111 68.72 120 1.3265 35.7 65.30 80 1 . 3386 36.7 67.72 130 1.3232 35 4 64.64 100 1 . 3328 36.3 66.56 140 1.3198 35.1 63.96 230 Standardizing Sweetened Condensed Milk TABLE 37. The relation between specific gravity and composition in sweetened con- densed skim-milk testing in the ratio of .50 per cent fat; 27.50 per cent M. S. N. F., and 70.00 per cent T. S. Tests made by J. A. Cross and H. J. Liedel. AT 60° F. AT 100° F. Per Cent T. S. Specific Gravity °Baume "Twaddell Specific Gravity °Baume "Twaddell 70.0 1.3436 37.1 68.72 1.3328 36.3 66.56 68.0 1.3329 36.3 66.58 1 . 3227 35.4 64.54 65.0 1.3134 34.6 62.68 1.3035 33.8 60.70 60.0 1.2836 32.0 56.72 1.2735 31.1 54.70 55.0 1.2588 29.8 51.72 1 . 2480 28.8 49.60 50.0 1 . 2284 27.0 45.68 1.2180 25.9 43.60 AT 120° F. AT 140° F. Per Cent T. S. Specific Gravity °Baume °TwaddeIl Specific Gravity °Baume °Twaddell 70.0 1.3265 35.7 65.30 1.3198 35.1 63.96 68.0 1.3175 34.9 63.50 1 . 3099 34.3 61.98 65.0 1.2968 33.2 59.36 1.2896 32.6 57.92 60.0 1.2683 30.7 53.66 1.2612 30.0 52.24 55.0 1.2419 28.2 48.38 1 . 2355 27.6 47.10 50.0 1.2119 25.3 42.38 1 . 2060 24.8 41.20 ' 1 From the above table it is ascertained that a difference of .10 degree Banme is equal to about .20 per cent T. S. in the case of sweetened condensed skim-milk of the composition given. Prac- tical application of this fact is made as follows : The condensed milk in the standardizing tank weighs 10,000 pounds, and tests Specific Gravity and Temperature 231 69.00 per cent T. S. The test desired is 70.00 per cent T. S. 70.0 — 69.0 = 1.00 per cent of T. S. short of that required. 10,000 X .01=100 pounds of T. S. short. The condensed product from the last batch should yield normally about 5,000 pounds, testing- 70.0 per cent of T. S. and 34.7° Baume at 140^ F. Since .10 Baume varies the T. S. test .20 per cent, upon 5000 pounds this variation would be equivalent to 10.0 pounds of T. S. per .10 degree Baume. (100 -f- 10) X -10 = 1.0 degree Baume necessary to add to the normal striking point. Therefore 34.7 -(- 1.0 = 35.7 or the strik- ing point upon the last pan batch necessary to make the correction desired. Based upon the foregoing tables, the unit temperature and specific gravity relation in sweetened condensed skim-milk of the test indicated, is given in Table 38. TABLE 38. Unit relation of temperature to specific giavlty in sweetened condensed skim-milk testing .50 per cent fat, 27.50 per cent milk S. N. F. and 70.00 per cent T. S. Temperature range. Decrease in specific gravity (or >ice versa) for each degree F. increase in temperature. Specific gravity. Baume. Twaddell. 40° to 80° F .00025 .00027 .00036 .020 .020 .020 .050 80° to 110° F .054 110° to 140° F .072 The above relation can be used to advantage in reducing spe- cific gravitj^ to a definite temperature when striking the batch at the pan. Example : Baume reading at 120° F. is 35,7. What is the Baume reading at 125° F. ? 125 — 120= 5, degrees F. over standard desired, 5X-03:= ,15, degree Baume to be deducted from the read- ing at 120° F. 35.7— .5=35.55, the Baume reading at 120° F. The graph under Fig. 71 gives the composition, temperature and specific gravity relation in Baume degrees in the case of sweetened condensed skim-milk of the composition named above. 232 Standardizing Swektknkd Condensed Mii^k This graph can be used within its limits to find the composition at any given Baume test and temperature ; or vice versa, the Baume test at any given composition and temperature. KEY TO FIG. 71 Curve 1 2 3 4 5 6 Fat per cent .36 .39 .43 .46 .48 .50 Sugar per cent 30.00 33.00 36.00 39.00 40.80 42 00 Total Solids per cent. . . . 50.00 55.00 60.00 65.00 68.00 70.00 SPECIFIC GRA Fig*. 71. Relation specific gravity and composition in sweetened condensed ekim-niilk in which the constituents are in following" ratio: .50 fat, 42.00% sugar, 70.00% total solids. Tests made by J. A. Cross and H. J. Iiiedel. Equipment 233 HOW TO STRIKE THE PAN BATCH. The method of striking sAveetened condensed milk is very sim- ilar to that given in Chapter XI for striking evaporated milk. The hydrometer most commonly used has a range of 26 to 37 graduated into tenths upon the Baume scale. This corresponds to 1.2185 to 1.3426 upon the specific gravity scale. Another common method consists in the use of a pycnometer cup such as illustrated under Fig. 72. The cup is designed for a narrow limit of volume adjustment. The weight of the cup filled with the condensed product varies with the specific gravity of the product, and the condensation is continued until the desired weight Pig. 72. is obtained. Pycnometer Cup. IMPROVED METHOD AND EQUIPMENT FOR MANUFACTURING SWEETENED CONDENSED MILK. For plants handling 10,000 pounds or more of whole milk to be manufactured into sweetened condensed milk, the use of the equipment illustrated under Fig. 73 will make it possible to man- ufacture the best possible quality of product. The complete unit is furnished in standard sizes and capacities to meet various requirements. Table 39 lists the principal standard sizes, with capacities based upon a ten-hour working day. The capacities can be increased by increasing the hours of operation. The different items making up the system are placed in the proper relation one to the other to best facilitate the handling of the condensed product. From the vacuum pan the condensed prod- uct flows by gravity into a weigh tank set upon a scale where the weight of the batch is obtained. From the drop tank the milk is pumped by means of a high pressure pump through a coil cooler, and from there it discharges into standardizing tanks set pre- ferably upon the second floor. These tanks are fitted with spe- cially designed power agitators, and they are of such size as to hold the condensed product from at least an entire day's run. 234 Standardizing Sweetened Condensed Milk TABLE 39. Capacities and Sizes of Standard Equipment for Manufacturing Sweetened Condensed Milk, Using the Mojonnier Process, ■^ d B 3 3 « s |.2 (S a P a Capacity of vacuum J"* pan in pounds of g sweetened condensed § 1 whole milk per hour O J, to Size of Hydraulic Pressure Pump Capacity of sweetened condensed milk Cooler in lbs. of sweetened condensed milk cooled per hour be a d 03 0.2 £12 6 tti.S "to M ill 5 &.S (U 73 a 'S3 <" • o J= I-.2 iSe.s o d ■35° 0,T3 M 10,000 to 15,000 50 300 12 2 12 3,000 500 15,000 to 25,000. .. 60 1,500 400 12 2 12 3,000 1,000 25,000 to 40,000... 72 78 2,650 2,950 800 800 14 14 3J^ 33-^ 12 12 6,000 6,000 1,500 1,500 40,000 to 75,000. .. 84 3,350 1,000 14 3M 12 6,000 3,000 75.000 to 125,000. . 84 3,350 1,000 14 3M 12 6,000 5,000 The advantages of this system over all other methods for handling sweetened condensed milk are briefly as follows : (1) The condensed product is not exposed to the air between the vacuum pan and the filling machines, thus helping to prevent mold growth. (2) The method of agitation used makes it possible to obtain a finished product with small milk sugar crystals, rendering it smooth to the taste and helping to prevent the settling of the milk sugar upon the bottom of the cans. (3) Control of the composition between closer limits than is possible by any other method. Figs. 76, 77 and 78 illustrate three other types of sweetened condensed milk coolers that are in common use. Equipmknt 235 ^\nS\\\\ \\\\\\\\v^^^^^^ 2 b I 236 Standardizing Sweetenkd Condensed Mii,k rifif. 74. Milk Sugar Crystals In Sweetened, Condensed Milk of Good Crystalline Quality. By Miss Iiucy Klein. Magnified 100 Diameters. Pig. 75. Milk Sugar Crystals in Sweetened, Condensed Milk of Poor Crystalline Quality. By Miss Iiucy Klein. Magnified 100 Diameters. Fig. 74 is a photomicrograph of milk sugar crystals in sweet- ened condensed milk of good crystalline quality, that is, one that is smooth to the taste. Fig. 75 is a photomicrograph of sweetened condensed milk of poor crystalline quality. The latter product is of low commercial value, and is one in which the milk sugar is very likely to deposit upon the bottom of the containers. SWERTENI-D CONDI-NSKD MiLK CoOIl^('-f) (4.) To calculate the pounds of sugar required. _ (S^P) + (G^Q) Problem 24, Example 25: Pounds PER CENT Products Fat M. S. N. F. Sugar T. S. Milk 10000.0 3.70 8.40 12.10 Condensed Whole milk 1000.0 10.00 28.00 38.00 Condensed Skim-milk. . . .05 29.95 30.00 Composition desired after condensing. . 8.00 20.00 44.50 72.50 Desired ratio of fat to milk solids not fat is .40 to 1. Desired ratio of sugar to fat is ,1798. Solution of Problem 24, Example 25, based upon Rule 22 : (1.) To calculate the average test of the mixed milk. 100000 X .0370 = 370, pounds of fat in whole milk. 1000 X -10 = 100, pounds of fat in condensed whole milk. 370 -f- 100 = 470, pounds of fat in mixed batch. 470 H^ 11000 — 4.27, per cent of fat in mixed batch. 10000 X .0840 = 840, pounds of S. N. F. in whole milk. 268 Standardizing Sweetened Condensed Milk 1000 X .28 = 280, pounds of S. N. F. in condensed whole milk. 840 + 280 — 1120, pounds of S. N. F. in the mixed batch. 10000 4- 1000 = 11000, total of pounds whole milk and con- densed whole milk in the batch. 1120 -^ 11000 = 10.18, per cent of S. N. F. in mixed batch. .05 H- .4 = .13, per cent milk S. N. F. required to equalize the fat in the skim-milk. 29.95 — .13 := 29.82, per cent S. N. F. available in the skim- milk for standardizing. (2.) To calculate the pounds of milk S. N. F. short. 4.27 ~ .40 — 10.68, per cent of milk S. N. F. required. 10.68 — 10.18 = .50, per cent of milk S. N. F. short. 10000 X .005 = 50, pounds of milk S. N. F. short. (3.) To calculate the pounds of condensed skim-milk required. 50-^-.2982 =: 166, pounds of condensed skim-milk required. (4.) To calculate the pounds of sugar required. 11000 X .0427 = 470, pounds of fat in the mixed batch. 166 X .0005 = .08, pounds of fat in the condensed skim-milk. 470 ^- .1798 = 2614, pounds of sugar required for the total batch. Solution of Problem 24, Example 25, based upon Formula 22 ' (1.) To calculate the percentage of fat in the mixed batch. (10000 X .037) + (1000 X -10) 10000 -+- 100 (2.) To calculate the percentage of S. N. F. in the mixed batch. _ (10000 X .084) + (1000 X .28) _ ^'- 10000 + 1000 ~ -=10.18 (3.) To calculate the pounds of unsweetened condensed skim- milk required. r^:?i?^ — .lois'jx looool Q- ^005 -^«« .2995 .40 Problems in Standardizing (4.) To calculate the pounds of sugar required. (11000 X .0427) + (166 X -0005 269 ^ .1798 Proof of Problem 24, Example 25 : = 2614. POUNDS PER CENT Products Fat M. .". N. F. Sugar T. S. Fat M.S. N.F. Sugar T. S. Milk .... 10000.00 370.0 840.00 1210.0 3.70 8.40 12.10 Cond. whole milk 1000.00 100.0 280.00 380.0 10.00 28.00 38.00 Cond. skim-milk 166.0 .08 49.72 49.8 .05 29.95 30.00 Sugar 2614.0 2614.0 2614.0 100.00 100.00 Stand- ardized product. . 13780.0 470.08 1169.72 2614.0 4253 . 8 3.41 8 50 18.96 30.87 Ratio of S. N. F. to fat obtained is 1 to .40. Ratio of sugar to fat obtained is 1 to .1798. STANDARDIZING SWEETENED CONDENSED SKIM-MILK BEFORE CONDENSING Problem 25: How to Calculate the Pounds of Sugar to Use in Sweetened Condensed Skim-milk. Solution of Problem 25, based upon Rule 23 : (1.) Multiply the pounds of skim-milk in the batch by the to- tal solids test of the skim-milk. Multiply the answer by the ratio between the total milk solids and the sugar in the product desired. The result will be the pounds of sugar to add to the entire batch. Solution of Problem 25, based upon Formula 23. 270 Standardizing Sweetened Condensed Mii,k Problem 25, Example 26 : Products Pounds M. S. N.F. Sugar T. S. Skim-milk 10000 8.83 8.83 Composition desired 28.00 42.00 70.00 Desired ratio of milk solids to sugar is 1 to 1.50. Solution of Problem 25, Example 26, based upon Rule 23 : (1.) To calculate the pounds of sugar required. 10000 X .0883 = 883, pounds of milk solids in the skim-milk. 883 X 1-50 =1325, pounds of sugar to use. Condense the batch sufficiently high to provide the proper fac- tor of safety. Solution of Problem 25, Example 26, based upon Formula 23 : U = (10000 X .0883) X 1.5 = 1325 Proof of Problem 25, Example 26 : POUNDS PER CENT Products m.s.n.f Sugar T.S. M.S.N.F. Sugar T.S. Skim-milk 10000 883 883 8.83 8.83 Sugar 1325 1325 1325 100.00 100.00 Standardized product 11325 883 1325 2208 7.37 16.42 23.79 Condense the batch high enough to provide the proper factor of safety. TABLES FOR ASCERTAINING SUGAR REQUIRED. The quantity of sugar to use for any corresponding weight of T. S. when manufacturing sweetened condensed skim-milk, can be ascertained from tables compiled for any composition desired, and for any quantity range necessary. The use of such tables helps to prevent errors, and it saves calculations. It makes it neces- Sugar Tables 271 sary in practice simply to ascertain the pounds of total solids m the batch, and then by reference to the table, to obtain the weight of sugar to produce a product of the composition desired. In Problem 25, Example 26, the product is to have a composi- tion of 28.00 per cent total milk solids and 42.00 per cent sugar, or in the ratio 1 part T. M. S. to 1.5 parts sugar. This is the composi- tion desired in the case of nearly all sweetened condensed skim- milk manufactured in the United States. In view of the fact that the above ratio is so simple, but little time, if any, could be saved by compiling tables for this composition. For any who might de- sire to compile a table either for a product of the above composi- tion, or of any composition desired, specimen Table 43 has been prepared. TABLE 43. Ratios between pounds of total milk solids in the batch, and pounds of sugar required, to make sweetened condensed skim-milk testing 28.00 per cent total milk solids, 42.00 per cent sugar, and 70 per cent total solids. Pounds T.M.S. Pounds Sugar Pounds T.M.S. Pounds Sugar Pounds T.M.S. Pounds Sugar Pounds T.M.S. Pounds Sugar Pounds T.M.S. Pounds Sugar 100 150 250 375 500 750 1000 1500 2500 3750 101 152 251 377 501 752 1001 1502 2501 3752 102 153 252 378 502 753 1002 1503 2502 3753 103 155 253 380 503 755 1003 1505 2503 3755 104 156 254 381 504 756 1004 1506 2504 3756 105 158 255 383 505 758 1005 1508 2505 3758 106 159 256 384 506 759 1006 1509 2506 3759 107 161 257 386 507 761 1007 1008 1511 2507 3761 108 162 258 387 508 762 1512 2508 3762 109 164 259 389 509 764 1009 1514 2509 3764 CHAPTER XIII THE COMPOSITION AiND STANDARDIZATION OF ICE CREAM MIXES SUGGESTED COMPOSITIONS OF VARIOUS ICE CREAM MIXES. It is possible to compound satisfactory ice cream mixes varying widely in composition, and there is probably no other dairy product that shows such large variations in composition both in the same and in the different localities, and even in the product of any single manufacturer where no attempt is made at exact chemical control. This is so because the ingredients used in making up an ice cream mix are so different in character and each fluctuates so much in composition. Again, it is some- times desirable to manufacture more than one quality of ice cream. Table 43 gives the composition of thirteen different ice cream mixes. The proper composition can be selected from the list to meet the needs of manufacturers in all localities. Ice cream of these several compositions is now manufactured in many different localities, and all have given satisfactory products. THE PHYSICAL AND CHEMICAL PROPERTIES OF VARIOUS ICE CREAM MIXES. The physical and chemical properties of nine of the most com- mon composition of ice cream mix are given in Table 44. Unless otherwise indicated, the values named are based upon actual determinations. One batch of mix corresponding to each composi- tion named, was carefully compounded and in turn these were used to make the various determinations. The raw materials used to compound these mixes consisted of cream testing 36.00 per cent of fat, superheated bulk condensed whole milk testing 8.00 per cent of fat, sugar and gelatin. [272] Composition of Mixes 276 TABLE 43. Suggested Compositions &f Ice Cream Mixes. PER CENT No. of Mix Fat Milk S. N. F. Sugar Gelatin T. S. 1 8.00 11.50 13.00 .50 33.00 2 8.00 12.50 13.00 .50 34.00 3 8.50 12.00 13.00 .50 34.00 4 9.00 11,50 13.00 .50 34.00 5 10.00 10.50 14.00 .50 35,00 5A 11.00 10.50 14.00 .50 36.00 6 12.00 8.50 14.00 .50 35.00 7 12.00 9.50 14.00 .50 36.00 7A 13.00 8.50 14.00 .50 36.00 7B 14.00 • 9.50 14.00 .50 38.00 7C 15.00 8.50 14.00 .50 38.00 8 16.00 7.50 14.00 .50 3S,00 9 18.00 7.50 14.00 .50 40.00 Composition Ratios. In standardizing ice cream mix it is usually necessary to know the ratio between the fat and the M. S. N. F., or that between the fat and the T. S. Both of these ratios are given for each of the nine compositions of mix. Ob- viously, there is quite a variation in these several ratios. Viscosity. This was determined by means of the Mojonnier- Doolittle viscosimeter described in Chapter XVII. The viscosity was determined at various temperatures immediately after pre- paring at 40° F., after aging 24, 48, and 72 hours each respec- tively. The results of this experiment prove: (1) The viscosity of all mixes regardless of composition, increases as the holding temperature decreases. (2) Viscosity in the case of freshly pre- pared mix is the same at equal temperatures, regardless of composition when compounded from the same products. (3) viscosity increases with the age of the mix. The increase with age is much greater in the case of ice cream mix high in milk solids not fat. This is no doubt largely due to the action of the acid that develops during aging, upon the casein and albumin contained in the mix. The gelatin content of the mix may also 274 Ice Cream Mixes exert a large influence upon its viscosity. The quality and quan- tity of the gelatin used determines largely the extent of its effect upon the viscosity of the mix. Titratable Acidity. This was usually higher both immediately after preparing, and also after aging, in the case of all mixes, containing the higher percentage of milk solids not fat. There is a close correlation between titratable acidity and viscosity. The percentage of titratable acidity in fresh ice cream mix is dependent upon the quantity of acid contained in the raw mater- ials used, and it is derived chiefly from the milk solids not fat in the raw materials. There is no general agreement as to what constitutes thcmost desirable percentage of acidity in ice cream mix at the time of freezing. A mix containing 12.00 per cent of milk solids not fat made from whole milk testing .16 per cent of titratable acidity and containing 8.60 per cent of milk solids not fat and from sweet butter without acid should test after condensing about .23 per cent of titratable acidity. Controlling the acid content of the mix between close limits would no doubt favorably influence the uni- formity of the flavor. The higher the content of milk solids not fat in the mix, the higher will be the titratable acidity in the same, when the same raw products are used. Specific Gravity. This value increases as the temperature decreases, regardless of composition. Changes in composition are immediately reflected in the specific gravity. Obviously the higher the fat content the lower the specific gravity for any given percentage of S. N. F. Weight per U. S. Gallon of Mix. This is based upon the specific gravity determinations at the various temperatures, com- pared with water weighing 8.34 pounds per U. S. gallon. Weight per U. S. Gallon of Ice Cream. The weight of one gallon of mix at 40" F. was taken as unity. The weight of one gallon of ice cream at various percentages of overrun was calcu- lated from the above unit basis. The results in Table 44 indicate the differences in the weight of ice cream of various compositions, at the same overrun. Available Heat of Combustion. This is given upon the basis both of one pound of mix, and of one Ur S. gallon of ice cream Specific Heat and Freezing Points 275 at 100 and at 80 per cent of overrun, respectively expressed as calories and as B. T. U. The factors given by Richmond^ were used. These were based upon the combustion of the three con- stituents in the human body, and take into consideration that portion of the protein which is not combusted, but which is voided in the form of urea. The gelatin was added to the milk proteins. The factors are as follows : — Available heat of combustion one kilogram butter fat=9.230 Calories. Available heat of combustion one kilogram milk sugar=3.950 Calories. Available heat of combustion one kilogram cane sugar=3.955 Calories. Availiable heat of combustion one kilogram protein=:4.970 Calories. Specific Heat. This was calculated from the values given by Hammer & Johnson.- The calculations were all made upon the basis of a temperature of zero degrees F., using the following formula : — (Per cent fat \ ,._ , /lOO^ — ^ per cent fat \ — 100 — ) "^ V 100 ) -^^^ It was assumed in these calculations that the specific heat of the cane sugar added to the mix, was the same as the specific heat of milk serum. Freezing Point. The freezing points were determined by the depression method using a Beckman thermometer. This value showed comparatively little fluctuation. The largest part of the depression is caused by the milk sugar and the cane sugar that are in the solution. A solution containing 6.00 per cent milk sugar and 14.00 per cent cane sugar was found to have a freezing point of 29.38° F. Calculated upon the basis of the water content only, the sum of the percentages of milk sugar and the cane sugar is proportion- ately larger than in ice cream mix. Mix No. 1 contains a total of about 19.21 per cent of milk sugar and cane sugar. Calculated upon a water content of 67.00 per cent this is equivalent to a concentration of 22.25 per cent, based upon the water content only, or 28.67 parts of the two sugars per 100 parts of water. 276 Ice Crram Mixes Heat Units Required to Melt Ice Cream. The feeling of cold- ness experienced in eating ice cream is due to the heat units that are absorbed in the mouth due to the melting of the ice cream. This is the sum of the normal heat and the latent heat. The cal- culation is shown in the case of ice cream containing 100 per cent overrun, and therefore weighing 4.60 lbs. per U. S. gallon, raised in temperature from 20° F. to 60° F. The method of calculation used is illustrated in the case of ice cream mix No. 1 as follows : — Normal heat=(4.60X.900) X 40=165.6 B. T. U. Latent heat=(4.60X.6700) Xl44=443.8 B. T. U. Total =609.4 B. T. U. These values in this table explain why the feeling of coldness varies with different ice creams. Ice cream made from mix No. 9 will feel about 12.00 per cent warmer to the tongue than ice eream made from mix No. 1. Nutritive Ratios, These are expressed from the standpoints of both, composition in the ratio : — fat : sugar : protein ; and available heat units in the ratio: — protein : ( f at -j- sugar). It is most significant that it is possible to compound a high quality of ice cream mix in Avhich the various constituents are in very nearly the right proportions to best stimulate growth and sustain life. Extremes in composition do not produce this favor- able result. For children, ice cream testing 10.00 per cent fat; 10.50 per cent milk solids not fat; 14.00 per cent sugar and .50 per cent gelatin; — totaling 35.00 per cent total solids, most nearly ap- proaches the theoretical requirements of a properly balanced ration. For adults ice cream testing 8.00 per cent fat; 12.50 per cent milk solids not fat; 13.00 per cent sugar, and .50 per cent gelatin, — totaling 34.00 per cent total solids, approaches very closely the theoretical requirements. The above ratios apply only when ice cream is consumed alone. It is very frequently consumed as a dessert, in which case its nutritive value influences the balance of the diet. The questions of flavor and palatability also' exert an important influence upon this problem. Ice creams rich in butter fat are preferred by Physicai, and ChEmicai. Prope;rtie;s 277 TABLE 44. The Physical and Chemical Properties and the Nutritive Ratio of Ice Cieam Mix. ! .9 5 < 1 1 After Aging 72 Hours OOOOCOiOOOO^O ki bC ^ "■^22 2 COC»5«>CCCC(MC-»N(M •o3 Ml ■Sfc-g lea a f^ § 1 1 I. M E o oo.-HOr-to>oi«toco § lOOOOOiOiOiOO OU3iOOOIO»CO»C ■s > s ooooooooo cccccccocccoecccco s 10 10IO»0101010"5»0 o O— lOOOOOOO o cocDcotOcoco:o:DeD .2 K " a o 1 •IS- 1250 2500 0000 7778 5000 9167 0000 3750 2222 Tji-^^TOCCC^COC^IM 4375 5625 4118 2778 0500 7083 7917 4688 4167 ii IJ s 5 OOOOOOOOO OOOOOOOOO r^coeocDiOto-^c^o ooooooooo ooooooooo co-^'-^'^'Oiocdooo ooooooooo t-. 3 CO ooooooooo ooooooooo cc ooooooooo u^ioo«raoioio>n« — IMCVl— '000 0-. t^l^ 1 ooooooooo OOUOOOOOOO OOOOOOOIOCJC^COOO f-ic^jco-^ioor^oooi Is 03 o 9.19 9.21 9.20 9.13 9.18 9.09 9.13 9.05 9.04 o rtrt.-.^rtooo>aj OCiOOiOSOOQOOO ■•f 00(MO«0><^100^00 OOOOSOSOOOSOOt^ OOOOJOOOOOOQOOOOO °g "IB -a g ti 1 o to i ■* 1.1022 1.1043 1.1031 1.0954 1.1005 1.0899 1.0946 1.0848 1.0841 o 1.1016 1.1030 1.1010 1.0949 1.0985 1.0880 1.0928 1.0835 1.0811 o 1.0957 1.0978 1.0970 1.0923 1.0927 1.0822 1.0867 1.0764 1.0749 o o tDi:Dr>-oas»oosi>-oo r^oco>0'<**coi>-t~*-<*< ooooooooo o ^OOOCMOt^t^O COOOCOOasOO(M.-"QO ooooooooo o 1.0772 1.0815 1.0917 1.0738 1.0728 1.0616 1.0667 1 . 0558 1.0526 Is .2o a o ooooooooo ooooooooo t^tO^DOi^iO'^C^O ooooooooo ooooooooo CO'<*<'*'>*iO»OCOOOO ooooooooo 1 ooooooooo ooooooooo c^cococo-^^-^-^-^ ooooooooo iOiOO»CO»OiOiO»0 ^csc^ii— oooa>i>»t* 1 ooooooooo <00ir300>0000 coooooooc^c^iooo :^l T-KMCO^iftOr-OQOi 278 Ice Cream Mixes TABLE 44 (Continued). a O ii 1l £ 3 ■f ■< C 3 > o 1 c c (5 S 3 c o B _o 15 o oi 1= B O OO^COiCOOOO^CO CM O rJH OS CD,'* C-t^t^t~^t^cor^coco iCiOiOiOiO»CiOiO»0 o '-^CMi-Hb-OtOt^CMCvl ^TpTjiCOTjiCCCOeOCO lOiOiCiOOiOiCiOiO o W(M.-'I^O»C(^COCM t_,^rtO^OOOO »cicutnoir5ic»oio»o o 0-. -^J^iC-^^COOO^COco oocooocooot'-oor^t-^ "<1*Tt4TpTji'rJ4Tt4Tj<-<*4'^ i ooor-c:i»ot^cocM COCOCOiOiOiO*0»0»0 «^T}1'*'^Ttl'^^TJlT}4 o OOOOOOiOt-COiOi-HO CO CO CO CO CO CO CO CO CO '*Tj1-«*1'^Tt"Tp-«*4-^f^ i ooooooooo ooooooooo r^cococoio»0'*c3 COCOCDUDCCCOCOCOCD CO ooooooooo ooooooooo CO'^'^Ji-.SllOiOCOOOO COCCCOCOCOOOCOCO'* i.g OOOOOOOOO ir3iOkoiow3ur5coiO»o 02 OOOOOOOOO OOOOOOOOO eOCOCOCO'^'rJH',^.^^' ooooooooo »-OCT.OClQOtOOOCq CO^H^^OOSOOt^cOOS Freez- ing Points Temp. i; t^O>OI^>O00Ot^O (NO^c^ic^-^-^coeo OOOOOOOOQOOOOOOOOO Specific Heat at 0° F. Cal- culated from Factors:- S.H. = (Fat OOOOlO^^r^r-^'-" ooOiOiOioooocoira O O 00 00 00 00 00 00 00 Available Heat of Combustion One Gallon Frozen Ice Cream at Different Per Cents of Overrun Calculated § oooo50"^'MOcor^ OSCOiOt^cO-^OOOOOi iOcotO':or^oooo^o4 „ _ rt « r-, « .^ es cs "a 00 O C*! O^ t>- C^ CO »0 lO c^^(^^ooo•^■^":)^^oo O^^C^-^COt^COI-^ Tj*-. ooooooooo OOiOOOOOOO 000000050C^C o o w 'o 03 a a o o _5 "S o X a c3 a; Ci OJ o ;-< 01 a a o o 01 a cc c3 u y, W a . £5 o — ' 1^ 0) 03 a o o c a3T3 cc o a 03 * CO CO o q CO 8 CO 8 CO CO CO GO CO 8 o o o o s g o S S CO O 00 CO CO 8 CO 8 I— 1 ■^ o o -^ 8 CO s o c^i o o 2 o 00 ° i^ o LO fa fe^ o o 00 00 CO O O o o d f>j '>i CO 00 1^1 - !M CO TtH LO CO r^ 00 Oi Constituents of Ice; Cream Mix 281 FUNCTIONS OF THE VARIOUS CONSTITUENTS OF ICE CREAM MIX. Each constituent of ice cream plays an important part in determining the quality of the finished product. Briefly these are as follows : (1) Fat.— The butter fat determines to a large extent the flavor and the palatability of the product. It is rich in vitamines and in heat units. The food value is rated largely by the fat content. (2). Milk Solids Not Fat.— The role played by the milk solids not fat is not sufficiently appreciated. Too high milk solids not fat may cause sandy ice cream, due to the presence of excessive milk sugar. Too low, may render it very difficult to obtain satisfactory overrun. The casein and albumin exert the largest influence upon the overrun. The milk solids not fat also largely influence the nutritive value of the ice cream, due to their bone and muscle forming ingredients, present in the salts and protein rspectively. These are also rich in water soluble B vitamines, and to a lesser extent in the water soluble C. It is most important to pay close attention to the content of milk solids not fat. (3). Sugar. — While the sugar added is obviously for the purpose of sweetening the product, and thus increasing its palatability, it also possesses high food value. It is the one constituent that exerts the most influence upon the freezing point of the ice cream. Pure solutions of cane sugar of different con- centrations were found to have the following freezing points : — 10.00 per cent, 30.87° F. ; 12.00 per cent, 30.64° F. ; 14.00 per cent, 30.38^ F., and 16.00 per cent, 30.11° F. Based upon the water content only, of the ice cream mix, the concentration is greatly in excess of these figures. (4) Gelatin. — Gelatin is a colloid, and a non-crystallizable substance. Its presence in ice cream helps to prevent the crystal- loids from separating in the form of large crystals. The prin- cipal crystalloids are the milk and cane sugars and the water. In ice cream mix of the proper composition the crystallization of the two sugars is not likely to be a troublesome factor. Water crystals are however always a factor of great importance as in- fluencing the smoothness to the taste of the finished product. One 282 Ice Cream Mixes of the chief functions of gelatin in ice cream, is its influence upon the water crystals. The gelatin retards the formation of water crystals, and helps to produce small water crystals, thus making a product more smooth to the taste than otherwise possible. Relation of Gelatin to Viscosity. — Gelatin has a large influence upon the viscosity of ice cream mix. This influence does not manifest itself until several hours after the mix has been kept at a low temperature. This is owing to the fact that the hydration of the gelatin is a slow process, and that many hours are required to complete the "setting." This is probably the principal ad- vantage gained by aging ice cream mix. In turn the increased viscosity produced by aging is a large factor in helping both to obtain and to retain the overrun in the ice cream itself. The ability of gelatin to increase the viscosity of water solu- tions is largely influenced by the quality of the gelatin. Admitted that all edible gelatins are made from fresh, clean stock, there still exists a wide difference in the viscosity of water solutions of equal strength all prepared from edible gelatin of high com- mercial quality. It has not been demonstrated if this difference is due to the diff'erence in the original raw materials from which the gelatin was made, or to the destruction during manufacturing processes, or by other causes, of the jellying power, or viscosity producing power of the gelatin. From a number of samples of edible gelatin, three samples were selected that were termed good, medium and poor respec- tively. Water solutions of different concentrations were pre- pared from each of the samples, and the viscosity of each solution was determined, after holding them in ice water for twenty-four hours, by means of the Mojonnier-Doolittle viscosimeter as de- scribed in Chapter XVII. The results are given in Table 46. The results in the following table show plainly the large influence of the quality of the gelatin upon viscosity. It explains why varying results are obtained in practice, when using equal amounts of different gelatins in which the quality varies. Relation of Gelatin to Incorporation of Air. — The ability of gelatin solutions to incorporate and hold air is best demonstrated Gelatin 283 by the Frohring gelatin air test. This test is described in Chapter XVII. TABLE 46. Influence of Gelatin Varying in Quality Upon the Viscosity of Water Solutions, Percentage of gelatin. Viscosity expressed in degrees retardation at end 24 hours 50°F. Good quality gelatin. Medium quality gelatin. Poor quality gelatin. Water only. No gelatin. 3.6 3.6 3.6 .10 .25 .50 .60 .75 1.00 1.50 7.0 7.0 8.5 14.0 235.0 Too viscous to de- termine viscosity Too viscous to de- termine viscosity by above method. 6.0 6.0 8.0 9.0 9.0 47.0 Too viscous to de- termine viscosity by above method. 6.0 6.0 7.0 7.5 7.5 8.0 43.0 Table 47 gives the results of several experiments that had for their object the determination of the volume of air that can be incorporated in different concentrations of gelatin solutions. The results show a marked difference between the different samples. The ability to hold air increases up to a concentration of about 60 per cent, after which it decreases with increasing concentration. When a concentration ranging from one to two per cent is reached the mixture will no longer retain any air. In the sample treated with the liquefying organism B. proteus there was a marked reduction in the air retaining properties of the mixture. Other Influences of Gelatin. — Gelatin constitutes an important addition to the food value of ice cream. Bogue^ points out that it functions as a true food, but that it is not a complete food nor is it the equivalent in food value of the casein and albumin. It is incapable of supplying more than one third or one half of the nitrogenous matter required in the diet. It helps to preserve the nitrogenous constituents of the body; is easily digested, and is readilj^ burned in the production of energy. Gelatin functions as a protective colloid, and prevents the coagulation of the casein in large lumps, thus aiding digestion and assimilation of all the constituents of the ice cream even in the case of the very young. From a dietary standpoint the presence of good gelatin in ice cream is very beneficial. 284 Ice Cream Mixes TABLE 47. Air Whipped Into Various Gelatin Solutions of Different Concentrations. Good Gelatin After Having Been Treated with Liquefying Organism (B Proteus) Incubating for 12 Hours at 68° F. Cooled in Ice Water, and Whipped After One Hour o d Q .9 2 § o o d M m.S aj'S. ^.2- O 0) < tC ?5 ^ CO 00 05 lO ^ ^ CO ^ 2 It" CO CO 00 00 CO CO CO •* CO CM CO o o 01 CI — S ? 8 a; 3 Q 1 .5 d ^1 d'.d i o o d m 2 -< o o o ^ rt< o t^ -* o o >>d t^ o CO t^ ^ ^ ^ CM o o Poor Quality Food Gelatin Whipped After Cooling in Ice Water One Hour 0) 3 Q sl .3 d °a > a dIS 53 O (U •« u O d ll d.a . SB ^ CO ^ o Oi 00 CO 00- CO 00 CM M >'2 "3 a el ^ 00 CO t^ t^ 00 CM 02 g o J5 OS CO CO Good Food Gelatin. 7X Quality. Whipped After Cooling in Ice Water One Hour 3 Q ii ■^ a c3 O d d S'a d.2- .2^0 ^!" o o CO 00 00 CM CO lo iC CO o "m a ^.& d b lO 00 00 CO CM CO 1— I o CO 2 § o ^ a a (U u c ° o CO o o s o » ^ = c: c C5 Sources of Supply 285 SOURCES OF SUPPLY OF INGREDIENTS MAKING UP ICE CREAM MIX. The ingredients composing ice cream mix are obtainable from a variety of different sources. The sources of supply of each ingredient are as follows : — (1). Fat. — This is present in all dairy products used for making ice cream. These include whole milk, skim-milk, cream, butter, sweetened condensed milk both whole and skim, plain bulk condensed milk, both whole and skim, evaporated milk and whole and skim-milk powders. Obviously in the above products that have been skimmed the percentage of fat is small, but in nearly all cases enough still remains to be taken into account. (2). Milk Solids Not Fat.— The sources of supply for M. S. N. F. are the same as in the case of fat. The selection of material to use is governed by local conditions, market prices, and quality available. If the materials used are of the proper quality, and are properly handled, the M. S. N. F. from the several sources mentioned will yield equally satisfactory ice cream. Products in which the milk sugar has crystallized out, should be so handled that the milk sugar will all pass into solu- tion before freezing the mix. If this is not done, sandy ice cream is very likely to result. (3). Sugar. — Either cane or beet sugar, both known as sucrose can be used to equally good advantage. When sucrose is not available, malt sugar, or corn sugar may be substituted to the extent of about 25 per cent to 40 per cent of the normal sugar or sucrose requirements. The common belief that the sweetening power of sucrose can be increased by inverting it by means of a weak acid solution has been discredited by the researches of Sale and Skimmer.* "When 342,236 (molecular weight) units of sucrose or ordinary sugar are inverted, 180.126 units of dextrose and 180.126 units of levu- lose are obtained theoretically. The mixture of dextrose and levulose is known as "invert sugar." Their experiments show "that if sucrose is assigned sweetening value of 100, the sweet- ening value of invert sugar is only 85. Since 100 units of sucrose by inversion become 105 units of invert sugar the net loss in 286 Ice Cream Mixes sweetening power by the inversion of 100 units of sucrose is about 11 units." According to previous experiments in the same laboratory, and also according to the investigations of Paul upon the sweet- ening power of lactose cited by the above authors the comparisons of the relative sweetening qualities of various common sugars are as follows: Sucrose=100, dextrose=50; levulose=150; maltose =60; and lactose=28. (4) Gelatin. — Only gelatin prepared especially for food pur- poses should be used, and this should be free from all injurious chemicals. According to Cromley,''' ''a good gelatin is one that solidifies in the shortest space of time ; has a low percentage of ash, a clean inoffensive odor ; makes a clear solution, and is with- out chemical or physical impurities." The water content of the gelatin should be determined as this will influence its commercial value. The usual range is between ten and fifteen per cent. (5) Miscellaneous Products. — Starch and eggs are sometimes used as fillers. These perceptibly increase the total solids of the mix. Their use is limited to special ice creams. It is products of this kind that make ice cream stand up in the dish after serving. Gum tragacanth is frequently substituted for gelatin, and func- tions the same as gelatin. Several commercial products commonly kno"wm by the general term "ice cream improvers" are in com- mon use. These consist of rennet or pepsin mixed with certain powders such as milk sugar. These products react upon the casein in the mix, causing an increase in the viscosity. They need to be used with care, and their action should be fully under- stood. In addition to the above products there is a large quan- tity of fruits and flavors used in making ice cream. The compo- sition of a few of the most important of these substances to- gether with a brief description of each is given in Table 48. The list includes one sherbet formula that will yield a fine product for use in connection with ice cream upon the Mojonnier Ice Cream Packaging Machine wherein the ice cream is packaged directly from the freezer into the carton, while still in the plastic condition, and then in turn hardened in the carton. I^LAVORS, Fruits and Nuts 287 TABLE 48. Name and Description of Flavors, Fruits and Nuts Used in Ice Cream, Also Sherbet Base. NAME AND DESCRIPTION OF PRODUCTS Ether Soluble Constit- uents Cane Sugar Fruit Sugars Total Solids Cocoa Syrup ^ and ^. Formula^: 2 lbs. sugar; 13^ lbs. cocoa; 1 quart water, and yi oz. cirmamon extract. Thoroughly mix the cocoa and sugar. Add the water; heat to 175° F. and hold for 20 minutes with constant stirring. Do not allow to boil. When cool add J^oz. cimiamon extract. The above is sufficient for 5 gallons of ice cream mix, or 10 gallons of ice cream Cocoa Syrup''. Formula h 1 lb. sugar M lb. cocoa, and 1 quart water. Prepare and use the same as above Cocoa Syrup^. Formula^: 2 lbs. sugar; 1 lb. cocoa, and 1 quart of water. Pre- pare and use the same as above Chocolate Syrup^ Formula: 1 lb. bit- ter chocolate; 1 lb. sugar; 1 quart water, and \i oz. cinnamon extract. Heat one pint of water to boiling; add the shredded chocolate, and stir imtil a pasty con- sistency is reached. Now add second pint of water, and heat until it simmers, stirring constantly. When cool add Y2 oz. cinnamon. The above makes enough syrup for 10 gallons of ice cream CarameP Sherbet Base^, Recommended for use upon Mojonnier Ice Cream Packaging Machine. Formula: 30 lbs. sugar; 18 ozs. of a 50 per cent solution of citric acid; 9 ozs. gelatin; 10 ozs. color; 2 gals, con densed skim-milk containing 25.5 per cent total solids; and 63^ gallons water. In case condensed skim-milk is not avail- able, equally satisfactory results are obtained by making the following sub- stitutions in the above formula: — (1) 4 gallons of whole milk and 43^ gallons of water, or (2) 5 gallons of skim-milk and 3 gallons of water. The above quantity makes up 10 gallons which should be frozen to yield 16 gallons of product, or 60 per cent of overrun. The above can be used as a base to which any desired flavor can be added. When fresh fruits are used omit enough water to bring the total volume up to 10 gallons. Mix all above products together cold, adding the citric acid just before freezing Per Cent Per Cent Per Cent Per Cent 7.16 5.27 3.32 35.70 26.26 39.63 61.50 45.18 58.65 14.64 5.22 24 48 26.10 52.73 82.07 .30 28.75 34.15 288 Ice Cream Mixes TABLE 48 (Continued). NAME AND DESCRIPTION OF PRODUCTS Ether Soluble Constit- uents Cane Sugar Fruit Sugars Total Solids Apples^ average 29 analyses Apricots*, average 11 analyses Bananas*, average 6 analyses Blackberries*, average 9 analyses Cherries*, edible portion, average 16 analy- Cherries^, maraschino Cranberries*, average 3 analyses Currants*, average 1 analysis Figs*, average 28 analyses Figs*, dried average 3 analyses Grapes*, edible portion, average 5 analyses Grapes*, dried, average 1 analysis Huckleberries*, average 1 analysis Lemons*, edible portion, average 4 analyses Muskmelons*, edible portion, average 1 analysis Oranges*, edible portion, average 23 analy- ses Peaches*, edible portion, average 2 analyses Peaches'', canned Pears'', edible portion, average 2 analyses . . Pineapple*, edible portion, average 1 analysis Pineapple', preserve, red, average 1 analy- sis Per Cent .50 .50 .60 1.00 .80 .26 .60 Per Cent Per Cent .30 .60 .60 .60 .70 Pineapple^ preserve, white, average 1 analysis Prunes*, edible portion, average 20 analyses Raspberries*, black, average 3 analyses. . Strawberries*, edible portion, average 22 analyses Strawberry Preserve" Strawberries, cold packed' Bitter Chocolate' Zanzibar Cocoa' Vanilla Extract' Gelatin' English Walnuts*, average 2 analyses — English Walnuts', average 2 analyses Pecans*, edible portion Pecans', edible portion Sajo Starch*, as purchased Eggs*, hens, edible portion, average 19 analyses Eggs, hens, white Eggs, hens, yolk .20 .10 .05 .50 .30 .16 .23 1.00 .60 .41 .23 54.77 25.38 63.40 64.22 70.50 64.68 12.00. .20 33.30 .68 19.72 19.73 18.18 33.14 41.40 31.65 17.32 Per Cent 15.40 15.00 24.70 13.70 19.10 33.08 11.10 15.00 20.90 81.20 22.60 65.20 18.10 10.70 10.50 13.10 10.60 9.35 15.60 10.70 60.34 58.29 24.40 15.90 9.60 57.51 24.02 98.61 96.01 9.07 86.08 97.50 96.31 97.30 98.35 87.80 26.80 13.80 50.50 Defects 289 THE RELATION OF COMPOSITION TO ICE CREAM DEFECTS. Many defects in ice cream attributed to other causes are due to defects in composition. (1) Fat. — Too low a content of fat sacrifices both the pala- tability and the food value of the ice cream. Too high fat pro- duces an ice cream that is difficult to assimilate, because of its large content of heat units. This is more objectionable in sum- mer than in winter. The outside ranges for good commercial ice cream are from 8.00 per cent to 14.00 per cent of fat. Above 14.00 per cent the ice cream enters a special class commonly called French ice cream. (2) Milk Solids Not Fat. — Improper control of the milk solids not fat is responsible for many ice cream defects. The ability both to obtain and retain overrun in ice cream depends largely upon its content of casein and albumin. The minimum should be not under 4.00 per cent of total protein. The reader is referred to Chapter XV for further discussion of this problem, Sandy Ice Cream, Cause and Prevention. — The content of milk solids not fat has a direct bearing upon the defect commonly known by the term "sandy ice cream," A careful investigation of this subject was made by one of the authors^'' and several as- sistants. In the course of these investigations several papers have appeared upon this subject namely : by Bothell/^-^^ Zoller and Williams ^^ and Williams". Sandiness in ice cream is readily detected by the consumer. It ranks as the worst of all the common ice cream defects, and it is responsible for large losses among ice cream manufacturers. Its occurrence is well night universal. It is caused by the milk sugar which is only about one fourth as sweet as sucrose and comparatively insoluble in the mix, particularly at the reduced temperatures used in making and holding ice cream. Milk sugar crystallizes in keystone shaped crystals, that are described by P. Groth^^ as : Monoclinic-sphenoidal. Cleavage in three directions nearly at right angles. Refractive indices, a = 1.517; y8=:1.542;=Y 1.550 +0.005 Bx^ c=10°, a=99^ 2E=83>4°. Sign—, sp. gr. 1.525 —1.534. 290 Ice Cream Mixes The sharp corners of the milk sugar crystals stick to the tongue giving the sensation of eating sand, from which the defect derives its name. The name is, however, slightly a misnomer, since milk sugar dissolves slowly in unsaturated water solutions while sand is insoluble, and the crystals crumble fairly readily under the pressure of the tongue or the teeth, which would not be true in the case of sand. Conditions That May Cause Sandy Ice Cream. — There are two general conditions under which sandy ice cream can be pro- duced. (1) By using products containing crystallized milk sugar re- gardless of the composition of the mix, when the mix is not pas- teurized. Such products include sweetened condensed milk, both whole and skim, and sometimes also plain bulk condensed milk both whole and skim. To produce sandy ice cream under these conditions, the ingredients composing the mix must be mixed cold, and frozen before the milk sugar has had sufficient time to go into solution. If the mix is standardized to the proper com- position and it is then pasteurized before freezing, there can be no danger of producing sandy ice cream when using products con- taining crystallized milk sugar. When sandiness is due to the use of products containing crystallized milk sugar, the sandy condition can be detected as soon as the ice cream is drawn from the freezer. If the mix was of the proper "composition, the sandiness will not increase while hardening, since only the milk sugar that was actually crystal- lized before freezing will appear as sand. This cannot go into solution after freezing. (2) By using a mix of improper composition, regardless of the products used, and also regardless of whether or not the mix has been pasteurized. In this ease, the sandiness will not appear until the ice cream has stood in the hardening room long enough for the milk sugar to crystallize out. Experimental Evidence. — A number of careful experiments were conducted, and these are reported herewith. (A) Influence of size of crystals and temperature upon the solubility of milk sugar crystals. Milk Sugar Crystals 291 (1) One lot of ice cream mix testing 18.50 per cent milk solids not fat and 40.00 per cent total solids was prepared by using a smooth sweetened condensed milk containing small milk sugar crystals as the source of the milk solids not fat. This was heated rapidly with constant agitation, taking 10 minutes to reach 140 deg. F. It required one minute to dissolve the milk sugar crystals. (2) Another lot of ice cream mix was prepared and handled the same as above, excepting that in this case, coarse, sweetened condensed milk containing large milk sugar crystals was used. It required three minutes to dissolve the milk sugar. (3) In a third experiment, a 5 per cent mixture of water and both fine and coarse milk sugar crystals were prepared. The solubility of the two sizes of crystals in water at different tem- peratures was carefully noted. The results are given in Table 49. TABLE 49. Influence of Temperature and of Size of Ciystals Upon Solubility of Milk Sugar Crystals. Temperature Time required Sample Size of of water. to dissolve crystals. No. crystals. Deg. F. Minutes. 1 small 40 33.00 2 small 68 2.50 3 small 140 .16 4 large 40 64.00 5 large 68 14.00 6 large 140 2.00 The results of the above experiments show the influence of the size of the milk sugar crystals upon the length of time re- quired to effect their solution at pasteurizing and other tem- peratures — obviously the larger the crystals, the longer the time required to dissolve them. (B) Influence of Pasteurization — There was prepared one lot of ice cream mix testing 12.50 per cent milk solids not fat and ^4.00 per cent total solids, using cream, skimmilk powder, gelatin, 292 Ice Cream Mixes sugar and water. The gelatin was dissolved in the added water, and the solution cooled before adding to the other ingredients, keeping the entire mixture down to about 40° F. One half of the above lot was frozen immediately without pas- teurizing. The other half was pasteurized at 140 deg, F. for 30 minutes, cooled and then frozen. Slight sandiness began to ap- pear in both lots after being in the hardening room 24 days. (2) There was prepared a second lot of ice cream mix test- ting 18.50 per cent milk solids not fat and 40.00 per cent total solids, using the same ingredients, and proceeding otherwise as described under (A). The ice cream from both the pasteurized and the unpasteurized portions began to show slight sandiness after being in the hardening room 7 days. The results of this experiment show that sandiness is not in- fluenced by pasteurization when milk solids not fat are obtained from milk powder, under the conditions named above. Influence of Composition of Mix — Ten bottles of ice cream mix of different composition were compounded. The raw materials used consisted of pasteurized cream, plain condensed skim-milk, sugar and gelatin, all being of high quality. A sample from each batch was frozen, and then transferred to a hardening room with a temperature of — 5° F. to 5° F. The essential facts and results of this experiment are given in Table 50. TABLE 50. Influence of Composition of Mix on Milk Sugar Crystallization. COMPOSITION OF BATCHES No of da.vs in hardening room No. of Extent of Mix Fat M.S.N.F. Sugar Gelatin T. S. before sandiness sandiness Per Cent Per Cent Per Cent Per Cent Per Cent appeared 1 8.00 11.50 13.00 .50 33.00 56 Slight 2 8.00 12.50 13.00 .50 34.00 27 Considerable 3 8.50 12.00 13.00 .50 34.00 27 Considerable 4 9.00 11.50 13.00 .50 34.00 36 Slight 5 10.00 10.50 14.00 .50 35.00 87 Slight 6 12.00 8.50 14.00 .50 35.00 No sandiness at end 87 days None 7 12.00 9.50 14.00 .50 36.00 do. None S 16.00 7.60 14.00 .50 38.00 do. None 9 18.00 7.50 14.00 .50 40.00 do. None 10 8.00 18.50 13.00 .50 40.00 6 Very heavy Ove;rrun 293 The results oi this experiment are most significant and prove conclusively the importance of the exact control of composition upon sandiness, particularly with regards to the milk solids not fat. The mix containing 18.50 per cent of milk solids not fat, showed sandiness at the end of six days while up to 9.50 per cent no sandiness appeared up to 87 days. (D) Influence of Amount of Overrun. — One lot of ice cream testing 8.00 per cent fat, 18.50 per cent milk solids not fat, 13.00 per cent sugar, and .50 per cent gelatin making 40.00 per cent total solids, was divided into two portions. One portion was frozen with as little overrun as possible, about 10 per cent, and the other portion with as much as pos- sible, about 100 per cent. Sandiness appeared in both lots of ice cream after they had been in the hardening room six days. The crystals in the lot with low overrun appeared throughout the experiment to be somewhat larger, and therefore more noticeable to the taste than in the case of of the lot with high overrun. The difference was probably due to the greater concentration of crystals in a given volume of the frozen product. The amount of overrun was not found to be of practical significance as affecting sandiness. (E) Influence of Miscellaneous Factors Upon Sandiness. The results obtained in this experiment indicate that the consistency to which the ice cream was frozen, the addition of lactic acid, TABLE 51. Influence of Miscellaneous Factors. Method of handling ice cream. Number of days in holding room before sandiness appeared. Remarks Frozen to hard consistency 5 All samples alike Frozen to soft consistency 5 as regards sandi- .3 per cent lactic acid added 5 ness. .4 per cent lactic acid added 5 .6 per cent lactic acid added 5 5 1 per cent pulyerized nuts added .... 294 Ice Cream Mixes or of pulverized nuts, had no influence upon sandiness. The milk sugar crystallized out about equally in all cases. (F.) Influence of the Solubility of Milk Sugar. The solu- bility of milk sugar has been studied by Dubrunfaut ;^® by C. S. Hudson^'; by E. Soillard^^ and by Mack & LiedeP''. Confirma- tory tests were made by Liedel in the Research Laboratories of Mojonnier Bros. Co. at the temperatures used by the above authorities and in addition the solubility was determined at temperatures both higher and lower than those reported by other authorities. Tabulating all of the results reported, we find the solubility of milk sugar to range as indicated in Table 3, and Fig. 7, Chap. II. The solubility of milk sugar was determined in water con- taining various substances, such as varying amounts of lactic acid, common salt and lime. The results thus obtained are given in Table 52. TABLE 52. Solubility of Milk Sugar in the Presence of Other Products. Compositions of Solubility of Milk Sugar in 100 parts at: Water Solutions 41° F. 50° F. 59° F. 70° F. 84° F. .20 per cent lactic acid. . . . 13.51 14.80 17.12 21.06 23.80 .40 per cent lactic acid. . . . 13.42 14.63 17.06 20.87 24.72 .60 per cent lactic acid. . . . 13.38 14.42 17.00 20.73 24.60 1.00 per cent lactic acid. . . . 13.20 14.31 16.95 20.45 24.49 .20 per cent salt (NaCl).. .. 13.60 13.77 17.06 20.21 24.85 .50 per cent salt (NaCl)..., 13.55 13.26 16.71 20.50 24.68 1.00 per cent salt (NaCl).. . . 13.48 13.13 16.90 20.43 24.80 Saturated Lime Water 13.60 14.85 17.60 20.84 25.02 Water only 13.36 14.90 16.78 19.50 24.40 The results given in Table 52 are not entirely consistent, due to analytical errors caused by the difficulties involved in making double solubility determinations. The differences found are so slight as to prove that the solubility of milk sugar in acid, alka- line and salt solutions within the limits of the experiment, is the same as in water only. Milk Sugar CRvsTAts 295 In another experiment, the separation of milk sugar from ice under different conditions was carefully determined. The water solutions were transferred to a hardening room with temperature about 0^ F, At the end of ten days the frozen samples were all returned to the laboratory, and immediately^ after the ice was melted, the water was decanted and the precipitated milk sugar was separated and weighed upon a Gooch crucible, in all cases where this was possible. The results of this experiment are given in Table 53. TABLE 53. Separation of Milk Sugar from Ice Under the Various Conditions Named. Water Used c. c. Grams Lactic Acid Used Grams Milk Sugar Used Days in Hardening Room before Crystals Separated Total Days in Hardening Room Grams Milk Sugar Separated Remarks 99.0 none 1.00 5 not determined 98.0 u 2.00 4 " 97.0 ii 3.00 3 u 96.0 « 4.00 3 " 95.0 11 5.00 2 10 .86 100.0 " 10.00 2 10 1.30 99.8 .2 1.00 5 10 none Milk sugar redissolved when ice melted. 99.8 .2 5.00 2 10 .85 99.8 99.6 2 'a 10.00 1.00 2 5 10 10 1.32 none do 99.6 99.4 .4 .6 5.00 1.00 2 5 10 10 .80 none do 99.4 .6 5.00 2 10 .86 The results given above prove that milk sugar crystallizes from ice, when present in amounts as small as one per cent. Such crystals are readily detected with the human eye. The amount actually crystallized could not be determined accurately 296 Ice Cream Mixes by the method used, since a considerable part of the milk sugar passed back into solution as fast as the ice melted. The quantita- tive determinations that were made show that the amount of sugar which separated from an acid solution of milk sugar, was no larger than in the case of pure water solution. The milk sugar which separated from the ice appeared to be more amorphous than crystalline. Its water content was not studied. The solubility of milk sugar in ice cream mix and in sucrose solution formed the basis of a careful study by Travis.^" He found the relative final solubility of lactose in different media at various temperatures as shown in Table 54. TABLE 54. Relative Final Solubility of Lactose at Various Temperatures and in Different Media According to Travis. Media. Grams of lactose per 100 Grams of water at: 0°C. 10° C. 25° C. Water (Hudson results) 12.50 15.92 22.8 Sucrose, 14 per cent solution . . 8.40 9.95 13.25 Ice cream mix testing 12.00 per cent fat; 14.00 per cent su- gar; .50 per cent gelatin and 36.00 per cent total solids . . ] 17.50 24.60 Not reported As the results in Table 54 show, lactose was found by Travis to be less soluble in sucrose solutions than in pure water, and more soluble in ice cream mix than in pure water. He attributes this difference to the possible effect of "some colloid or colloids in the ice cream mix," In view of the ease with which lactose crystals separate from ice even at as low concentrations as one per cent, as shown in Table 54, Travis' results offer an explanation as to why its separation in the form of sandiness in ice cream is not larger than usually encountered. Conclusions: — (1). Sandiness in ice cream is caused by the milk sugar contained in the mix. The largest single factor caus- Sandiness 297 ing sandiness is an improper content of milk solids not fat. A mix containing 18.50 per cent milk of solids not fat developed sandiness in the frozen product at the end of six days, while all mixes containing 9.50 per cent or less of milk solids not fat, did not show any sandiness after the frozen product had been in the hardening room 87 days. Ice cream mix containing 12.50 per cent of milk solids not fat did not show any sandiness until the ice cream was 27 days old. It is probably very seldom that ice cream is kept for this length of time. A content of 12.50 per cent of milk solids not fat is equal to about 6.70 per cent of milk sugar, or about the limit recommended by Bothell (cited above). Ice cream can contain more than the above limit of milk solids not fat, but if it goes quickly into consumption there will be no complaints from sandy ice cream. The next largest single factor causing sandiness is the age of the ice cream. The older the ice cream, the more likely is sandi- ness to appear. Complaints from sandiness are most liable to come from small dealers who move their ice cream slowly, or in the case of special flavors that meet with a limited demand. (2). Solutions containing as little as one per cent of milk sugar contain crystallized milk sugar after being in the hardening room for eight days or less. The increased solubility of milk sugar in ice cream mix as reported by Travis may account for the fact that larger quanti- ties of milk sugar can be safely used without causing sandiness in ice cream, over the amount that would theoretically produce sandiness. The greater the concentration of milk sugar in ice cream, the sooner will the crystals become apparent to the taste. In all cases the milk sugar crystals will be visible under the microscope, before they become apparent to the taste. The size of the milk sugar crystals was found under the microscope to vary con- siderably. The larger the crystals obviously the more apparent to the taste is the sandiness of the ice cream. (3). Pasteurization of the mix, particularly where the milk products used contain crystallized milk sugar, helps to retard sandiness in the case of a mix containing an excess of milk sugar, over that suggested by good practice, and it helps to prevent it entirely when the mix is of the right composition. A mix com- 298 Ice; Cream Mixes pounded from milk products containing crystallized milk sugar, if not pasteurized, will show up sandiness immediately after freezing regardless of the composition of the mix — the larger the milk sugar crystals in the raw products, the more apparent will be the sandiness in the finished product. (4). Sugar.— Too low sugar content gives a product that is insufficiently sweet ; too much sugar, one that is excessively sweet. A product containing excessive sugar has a low freezing point, and consequently is more difficult to keep in good condition in the dealers' cabinets. The best range of sugar is from 13.00 to 14.00 per cent. Also the more sugar that is used, the more difficult it is to obtain the desired overrun. Further discussion of this subject will be made under Chapter XV. (5). Gelatin. — One of the most important physical properties of ice cream is its texture, or in other words, its smoothness to the taste. This is caused principally by the size of the water crj^stal — obviously small water crystals producing an ice cream that is smooth to the taste and large water crystals one coarse to the taste. Several factors influence the size of the water crystals, but probably no single factor has greater influence than the gelatin content of the ice cream. A careful experiment was made to determine the proper limits of gelatin to use. A quantity of ice cream mix was prepared test- ing 8.00 per cent fat, 12.50 per cent milk solids not fat, 13.00 per cent sugar, making 33.50 per cent total solids. This was divided into different lots and these in turn handled as shown in Table 55. The various lots were all frozen quickly, and then transferred to a hardening room with temperature around 0^ F., and kept there- in for the time indicated in Table 55. The results given in the following table prove the value of adding gelatin to ice cream. The best results were obtained by adding .50 per cent gelatin to the mix before pasteurizing. Gela- tin usually contains only about 83.00 per cent of total solids. The addition of .60 per cent of gelatin will provide about .50 per cent of the water free substance. An excess of gelatin produces an ice cream that does not melt readily upon the tongue, besides it unnecessarily increases the cost of the ice cream. The possible influence, if any, that gelatin may exert upon the crystallization of the milk sugar is not known at this time. GeIvAtin and Water 299 It would be theoretically possible for the gelatin to retard the crystallization of the milk sugar, as well as the crystallization of the water. (6.) Water. — The water content of ice cream influences both its chemical and physical properties. Excessive water impairs the food value of the ice cream. The maximum limit under good practice is 67.00 per cent water, corresponding to 33.00 per cent total solids. The minimum- limit is 60.00 per cent of water cor- responding to 40.00 per cent total solids. TABLE 55. Influence of Gelatin Upon the Physical Properties of Ice Cream. How Mix was Treated How Gela- tin was Added Percentage Gelatin Added Condition of Ice Cream one day after Freezing Condition of Ice Cream eight days after Freezing Numerical Quali'.y Rank of various lots of Ice Cream at end of Eight Days Pasteurized at 140° F. held for 4 days at 40° F. Before pas- teurizing .50 Smooth Smooth 1 Not pasteurized held for 4 days at 40°F. After hold- ing 4 days. Just before freezing none Coarse, grainy Coarse, not fit for sale 6 " " .20 Coarse Coarse 5 " " .40 Slight grain Coarse 4 " " .50 Smooth Smooth 2 " " .60 Smooth Smooth 2 .70 Smooth but Ice Cream did not melt readily Smooth but slimy 3 1.00 Smooth|but Ice Cream.did not melt Slimy. Not fit for sale 6 The influence of the water content upon the physical property of ice cream is usually not fully understood nor fully appreciated. It is the size of the water crystals that determines the texture or smoothness of the product. The best work reported to date upon this subject is that by Hall.-^ Scale showing relative diameter of smooth and coarse textured crystals is reproduced under Fig 79. Hall found that, "Cream which left the freezer having 10 per cent of its water frozen, upon reaching 20 degrees had 42 per cent of its water frozen ; at 10 degrees, 55 per cent, and at minus 5 degrees 67 per 300 Ice Cream Mixes cent. It is doubtful if over 70 per cent of the water in ice cream is ever frozen. No matter at what temperature the ice cream may leave the freezer, the continued freezing in the hardening room follows the law as represented by the curve under Fig. 80. Tig. 79. Scale Showing- Relative Diameters of Smooth and Coarse Texture Crystals. 30 25 20 ^ 15 '—■n , ^- . ^^t" — ». — X j^_> ^^ + \ _s S 10 15 20 25 30 35 40 45 50 55 60 65 70 75 Per Cent of Crystals Fro-'"" Pig". 80. per Cent of Prozen Crystals. Hall applies the same principles of crystallization to freezing the water content of ice cream mix as are described in this book for controlling the milk sugar crystals in sweetened condensed milk. Namely, "slowly formed crystals are large, and quickly formed crystals are small." He recommends placing the ice cream as it comes from the freezers in a hardening room of very low temperature, say — 15° F. Then after the ice cream has hardened, transferring it to the regular hardening room with temperature of about 5° F. He further points out the fact already recognized by many manufacturers that "small cans on account of being quickly frozen, usually contain smoother texture cream than large cans." Standardization 301 THE STANDARDIZATION OF ICE CREAM MIX. Definition and Advantages.— The standardization of ice cream in a broad sense, has reference to the control of the fat, milk solids not fat, sugar, flavor, color, and of the overrun in the finished product. This chapter will treat more especially of the chemical control of the ingredients making up the mix, while Chapter XV treats of the control of the overrun. In no other branch of the dairy industry can such important results be obtained by complete standardization as in the ice cream industry. The three main advantages to be gained are (1) turning out a product of uniform composition; (2) manufacturing with the greatest possible .degree of economy; and (3) avoiding the marketing of a product under the legal or trade standards. Steps Involved. — The steps involved in standardizing ice cream mix are as follows: (1). Ascertaining the pounds, and the fat and T. S. tests of all materials on hand or available that are to be used for making up the batch. If the tests of the available materials are made at the plant, all of the precautions usually required in collecting the samples must be observed. Accuracy of the tests can be of little value unless the samples upon which the tests are based are exactly representative of the entire lot of material in question. (2). As a rule, it is not necessary for standardizing purposes to test with the Mojonnier Tester all the materials available for making up the batch. However, it is recommended that all ma terials purchased be tested, as that is the only satisfactory method of checking purchases, and at the same time this affords a large help in compounding the mixes. Also, if the exact test of the materials available for standardizing is known it will make for greater accuracy in the final standardization. (3). Determining the pounds that the batch is to contain, and the percentage of fat, M. S. N. F., sugar and other ingredients, that the batch is to contain after standardizing. It is usually necessary to manufacture not more than two different standard- ized products. The standards to be followed are sometimes set by State or Federal authorities, and again individual manu- facturers may elect to set special standards of their own — the same being higher in fat or T. S., or both, than the legal standards that might otherwise govern. 302 Ice Cream Mixes (4). Calculating the pounds of fat and T. S. that the batch should contain, and with this as a basis, determining the pounds of various materials required to make up the batch. (5). After the materials for the batch have all been very thoroughly mixed, a sample is taken to be tested for both fat and T. S., also record is made of the total pounds of each material composing the batch. Great care is necessary to get a sample that is representative of the entire batch. (6). Computing the material required for standardizing the batch to the desired standard upon the basis of the weights and tests as found under (5). GENERAL METHODS OF COMPOUNDING ICE CREAM MIX. Several methods are available for compounding and standard- izing ice cream mix, as follows : (A). By Using a Vacuum Pan. — This is commonly known as the Mojonnier method, and is covered by the pending process patents of one of the authors and his brother.-- Where this method is possible, it has numerous advantages over all other methods. The whole milk is sampled and tested for fat .and T. S., and the necessary fat in the form of cream or butter, and the necessary sugar and gelatin, are added to the milk in the hot wells. The batch is then condensed to the point desired. After condensing, the batch is weighed, homogenized, cooled, tested for fat and T. S. and standardized to the point desired. Under some conditions, it may be desirable to condense the product considerably in excess of the concentration desired, and to dilute it back with water to the proper concentration just before freezing. Mix, so prepared, can be stored for a considerable time, and shipped considerable distances. Peterson and Tracy-'' made a study of ice cream mix prepared in a vacuum pan. Their findings confirmed the foregoing state- ments. They also made a bacteriological study of mix prepared as above, and of ice cream produced from it. The number of bacteria found by them in the different stages of manufacture are given in Table 56. Prepared in Vacuum Pan 303 TABLE 56. Number of Bacteria per cc. in Ice Cream Mix Prepared in a Vacuum Pan at Different Stages of Manufacture. Before heating in hot wells. Direct from vacuum pan. Direct from homogenizer. After addition of gelatin. In the frozen ice cream. 9,600,000 800 1,400 1,450 2,600 2,260,000 20,000 26,200 26,250 31,000 The best practice is to add the gelatin to the hot wells before heating the milk, rather than to the mix after condensing. This will help to reduce the bacteria count. Mix prepared under vacuum was found to have very excellent keeping qualities as found by the results indicated in Table 57. TABLE 57. Keeping Qualities of Ice Cream Mix Prepared Under Vacuum and Stored at 32° to 35°F. Day in storage. Bacteria per cc. Condition of mix. 1,400 Very good 1.700 Very good 14 762,000 Good 23 42.210.000 Fair 32 188,500.000 Fair (frozen into ice cream) The results in Table 57 show both the low content of bac- teria in mix made as described above, and the excellent keeping qualities of the same. Handling operations after condensing, if care is taken, do not appreciably increase the bacteria count. The mix stored at the temperatures named were of excellent keep- ing quality, and remained in good condition up to two weeks. The specific gravity of ice cream mixes of nine different com- positions, and at various temperatures, are indicated upon the 304 Ice Cream Mixes chart under Fig. 81. This can be used as the basis for arriving at the proper striking point, when finishing the batch at the pan. Key to Fig. 81. Cujve 1 2 3 4 5 6 7 8 9 Fat 8.00 8.00 8.50 9.00 10.00 12.00 12.00 16.00 18.00 T. S 33.00 34.00 34.00 34.00 35.00 35.00 36.00 38.00 40.00 Sugar 13.00 13.00 13.00 13.00 13.00 13.00 13.00 13.00 13.00 Gelatin .50 .50 .50 .50 .50 .50 .50 .50 .50 SPECIFIC GRA VJTY IN DEGREES BAUME rig". 81. Specific Gravity of Nine Different Compositions of Ice Cream Mix at Various Temperatures. This chapter contains elsewhere methods of calculation recom- mended to cover problems of this kind. Successive Steps 305 (B). By mixing condensed products of various kinds. A large variety of combinations are possible, and usually if the proper methods of calculation are used, such dairy products of the prop- er quality, that may be available, can be mixed together and made to yield a satisfactory quality of mix. One extreme example would be skim-milk and cream; another v^ould be skim-milk powder and butter. Problems involving these various combina- tions will be found elsewhere in this chapter. SUCCCESSIVE STEPS INVOLVED IN STANDARDIZING ICE CREAM MIX. Unless the mix is compounded at the vacuum pan, two meth- ods of standardizing are possible as follows: (1) Ascertain the exact fat and T. S. tests of all products available, and upon the basis of these tests mix the same in the right proportion to obtain a product of the test desired. This method is not recommended, as it involves considerable work not required by the method im- mediately following. It is well, however, to test all products pur- chased for fat and T. S. to determine if they compl^y with the purchase specifications. (2). Compound the mix upon the basis of the approximate tests of the materials on hand. Test the mixture for fat and T. S., using the Mojonnier Tester. (3). Calculate by methods that follow in this chapter, the materials that will be required to standardize the batch to the proper content of fat, M. S. N. F. and sugar. How to Sample, Test and Weigh the Batch. Follow method of sampling recommended under Chapter VI. Use the Mojonnier Tester for making all fat and T. S. determinations. "Where pos- sible, obtain directly the weight of the batch. If impossible to weigh the batch, obtain the total gallonage, and calculate the pounds from the figures given in Table 58. Use the Green Gauge instead of a scale to ascertain the total pounds of mix in the holding tank. Order of Operations in Standardizing Ice Cream Mix: (1). Test both for fat and T. S. as far in advance as possible all prod- ucts that are to be used for standardizing. 306 Ice Cream Mixes TABLE 58. Approximate Weight per Gallon of Water and of Various Dairy Products. Temperature About 68° F. Name of Product Per- centage Fat Percent- age Total Solids Pounds in One U. S. Gallon Name of Product Per- centage Fat Percent- age Total Solids Pounds in One U. S. Gallon Water 8.34 30.00 36.24 8 35 .20 8.80 8.64 35.00 40.79 8 31 Whole Milk 3.00 11.40 8.59 Cream 40.00 45.35 8.38 Whole Milk 3.50 11.60 8.60 Ice Cream Mix. . . . 8.00 34.00 9.16 Whole Milk 4.00 12.30 8.61 Plain condensed skim-milk 1.00 26.00 9.18 Whole milk 5.00 13.00 8.62 Plain condensed whole milk 8.00 30.00 9.05 Mixed milk and cream 10.00 18.02 8.54 Evaporated milk.. . 8.00 26.15 8.90 Mixed milk and 15.00 22.57 8.47 Evaporated milk.. . 7.80 25.50 8.88 eream Sweetened con- densed skim-milk 1.00 70.00 Cream 20.00 27.13 8.43 8.39 11.16 Sweetened con- densed whole milk s.oo 73.00 Cream 25.00 31.68 10.90 (2). About half an hour before the sample from the batch is ready, do everything necessary to begin making fat and T. S. tests. (3). Keep the fat and T. S. dishes in the respective ovens for 5 minutes, under proper heat and with the vacuum on. (4). Transfer the dishes from the ovens to the coolers. Keep the water circulating. Weigh the T. S. dish with cover at the end of 5 minutes, and the fat dish alone at the end of 7 minutes. Record the weights and numbers upon the laboratory report Fig. 53, Chap. VII. Replace the dishes in the coolers. (5). Mix the sample thoroughly. (6). Fill the one gram pipette to the mark, and transfer the milk to the previously weighed dish, and weigh the dish with milk immediately. Fill the 5 gram pipette to the mark, and by means of the weighing cross, weigh about 5 grams into the fat extraction flask. ^ ^^IIMI (7). Prepare the sample for the T. S. and the fat ovens re- spectively; heat in the ovens, cool in the coolers, and weigh an directed. Successive Steps 307 (8). Calculate the percentages of fat and T. S. and transfer the results to the ice cream mix and cost report, Fig. 82. (9). Calculate the pounds of material necessary to add, select- ing and using the rule that may apply. giaM.P, 31 D«le ICE CREAM Plane MIX AND COST REPORT Batct Libo-ion i<.» P.>i»i> c... 't™." ■■.,.<. [HHad itUca ... iS ••■^ .... T»^.-. C.-» 1 1 C.«. 1 1 1 1 1 1 1 Sk.mUU^,»^« 1 1 1 1 1 1 1 1 Nui. 1 1 1 ^^ '•""- 1 "•"•"" "" *"-■ ..■Sri. c™ „.,... .,.„.„.„ LabomcT >'•■• P*' ».•• Added to standardize •■' 1 ""•• ,i- — ^°s;.r;."" .'■.•n";u,|,.';.ri.| '.r.i' ^;:^:^' \ '^s.t 1 I j 1 T,.l ,.., .f ...,„ „,. — i= O.llo« ... .<]... ,. ...„.„„. Gdl«.. l« c».n a»l. Cnnd ....1 P.-..4. &I ..u,. .!■ Cr«>d .GUI (.tlon. .1 oil. C„. „, cs.. .r. C,.« ,.,.1 ., ..11.™ K. „,„ ^, C... p.. nil." .« cr«« l,„I.M 0..m,n «.., ob..l«tf A..ru. o«r™» •„■, C... p„ nllo. on«..l «.<■ Tig". 82. Ice Cream Mix and Cost Report. (10). Add the standardizing materials to the batch. Mix thoroughly. Make a retest for fat and T. S. Complete all pos- sible or necessary calculations upon the above report blank. The use of this blank reduces the possibilities of errors to a minimum; provides a means of computing the cost per gallon of the mix, and gives a clear history of every batch of ice cream made. Any troubles that may arise can be more readily traced if a record of this kind is kept. 308 Ice Cream Mixes Standardizing and Holding Tanks for Ice Cream Mix. Several different designs of suitable tanks are available for the mixing and holding of ice cream mix. In small plants the same tank can be used as a batch mixer, pasteurizer, cooler and holder. Figs, 83, Tig. 83. Ice Cream Batch Mixer. Courtesy Creamery Package Mfg. Co. 84 and 85 illustrate tinned copper tanks of this kind. Figs. 86 and 88 illustrate glass enamelled batch mixers, and Fig. 87 a glass enamelled standardizing and holding tank. The size of tank to Fig-. 84. Ice Cream Batch Mixer. Courtesy J. G. Cherry Co. use is governed by the quantity of the output. Where the out- put so warrants, the larger the tanks used, tiie fewer the stand- Batch Mixers 309 ardizations that are necessary, and the more exact the control that can be maintained over the finished product. Fig'. 85. Ice Cream Batch Mixer. Courtesy Davis-Watkins Dairymen's Mfg. Co. Pig". 86. Ice Cream Batch Mixer. Pig". 87. Ice Cream Holding' Tank. Courtesy The Pfaudler Co. 310 Ice Cream Mixes Kinds of Problems Encountered in Standardizing Ice Cream Mix. Numerous methods have been suggested and used for standardizing ice cream mix, but usually the attempt has been Fig-. 88. Ice Cream Batch Mixer. Courtesy Jensen Creamery Machinery Co. to standardize the fat only, paying but comparatively little at- tention to the solids other than the fat. In the methods which follow, the fat, M. S. N. F. and the sugar are taken into con- sideration, and if these methods are used as recommended, all can be standardized with equal accuracy. Several different com- binations of results are possible, all requiring different calcula- tions as follows : (1). Fat Under, and T. S. Over the Standard Desired. The same method of calculations can be used when both the fat and the T. S. are over the standard desired, but with the fat in a Key TO Factors 311 lower ratio than the T. S. This is covered by problems 29 and 30. (2). Both the Fat and T. S. Are Under the Standard Desired. Three methods of calculations are given for this combination. This is covered by problems 31, 32 and 33, (3). Fat Over, and T. S. Under the Standard Desired. The same method of calculation can be used when both the fat and the T. S. are over the standard desired, but with the fat in a higher ratio than the T. S. This is covered by problems 34 and 35. (4). Both the Fat and the T. S. Over the Standard Desired, and in the proper ratio one to another, making it necessary to add sugar and water only. This is covered by problem 36. The above problems are solved in this chapter both by rules and formulas, and also by examples under each rule and formula. KEY TO FACTORS IN FORMULAS FOR STANDARDIZING. ICE CREAM MIX A = The percentage of fat desired in mix. A^ = The percentage of fat short. B = The percentage of M. S. N. F. desired in mix. B^ = The percentage of water-free gelatin desired in the mix. C = The percentage of fat in the cream. C^ = The percentage of fat in the condensed milk. D = The percentage of M. S. N. F. in the cream. D^ = The percentage of M. S. N. F. in the whole milk. E = The percentage of fat in cream available for standard- izing. E^ = The percentage of fat in butter. E- = The percentage of fat in the whole milk. F = The percentage of fat in the ice cream mix before standardizing. F^ =: The percentage of fat in the condensed whole milk. F^ r= The percentage of fat in the whole milk. F^ = The percentage of M. S. N. F. in the condensed whole milk. G z= The pounds of M. S. N. F. in mix after adding cream. 312 Ice Cream Mixes H = The pounds of M. S. N. F. short. H^ = The pounds of condensed whole milk K = The pounds of mix short. K^ = The pounds of mix possible to make. L .= The pounds of fat short. M := The pounds of mix before standardizing. M^ = The pounds of mix after adding cream. M^ = The pounds of mix desired. N = The percentage of M. S. N. F. in the original mix. N^ = The percentage of M. S. N. F. in the mix after adding the cream. =: The pounds of cream required. 0^ = The pounds of butter required. P = The percentage of M. S. N. F. in the mix after add- ing condensed milk and cream. P'^ = The pounds of whole milk on hand. P^ = The pounds of whole milk required. R = The ratio of fat to M. S. N. F. S =: The percentage of M. S. N. F. in the milk powder. S- =: The pounds of milk powder. S =: The pounds of gelatin required. U = The pounds of sugar required. V := The percentage of sugar desired. V^ =z The percentage of T. S. in the gelatin. W =: The pounds of M^ater required. COMPOUNDING AN ICE CREAM MIX TO APPROXIMATE TESTS. The procedure to follow in making up the batch of ice cream mix before testing and accurately standardizing is illus- trated and explained in the directions here given, and by using the ice cream mix report illustrated under Fig 82. The first column of the left hand side of the report shows the raw materials on hand from which it is necessary to select the materials that are to be used in making up the batch. The per- centages of fat and M. S. N. F. in the different materials should be determined by tests made in advance, or the percentage may be taken from former tests of these substances received from the same source, provided that the composition does not vary Composition of Products 313 widely in different deliveries. In this problem, the percentages of fat and M. S. N. F. in the different materials used were de- termined in advance and may be found in their respective places in the report at the upper right hand side. When gelatin or other stabilizers are used they may be in- cluded with the M. S. N. F. In this batch .50 of one per cent of gelatin was added. Table 59 gives the average composition of the products most commonly used for making up ice cream mix. These results are accurate enough to use when compounding a mix to an approxi- mate test. TABLE 59. Approximate Composition of Products Used in Ice Cream Mix. Name of Product Per Cent Fat Per Cent M.S.N.F. Per Cent T. S. Name of Product Per Cent Fat Per Cent M.S.N.F. Per Cent Sugar Per Cent T. S. Butter Skim-milk 84.00 .10 1.50 8.70 85.50 8.80 Plain cond. Skim-milk .50 25.50 26.00 Fresh milk 3.50 8.50 12.00 Plain cond. whole milk 6.00 22.00 28.00 Cream 15.00 18.00 7.88 7.59 22.88 25.59 " " 8.00 27.00 33.00 Cream Cream 20.00 7.41 27.41 Sweetened cond. skim- milk .50 27.50 42.00 70.00 Cream 25.00 6.94 31.94 Sweetened cond. whole milk 8.00 20.00 42.00 70.00 Cream 30.00 6.48 36.48 Skim-milk powder 1.00 94.00 95.00 Cream 40.00 5.55 45.55 Whole milk powder 26.00 69.00 95 00 Cream 50.00 4.63 54.63 Sugar 100.00 100.00 Evaporated whole milk 7.80 17.70 25.50 Gelatin 86.00 Evaporated skim-milk 40 22 00 22.40 314 icE Cream Mixes Example 27: PROBLEM 2G: HOW TO COMPOUND ICE CREAM MIX TO APPROXIMATE TESTS. Products Pounds Per Cent Pounds Fat M. S. N. F. Fat M. S. N. F. Whole milk 3400 4.00 8.50 136.00 299.00 Skim-milk 1360 * 8.70 118.32 Condensed skim-milk 1300 25,00 325.00 Butter 84.00 Skim-milk powder — 95.00 The above products are on hand and it is desired to utilize completely the first three products named, to make up a batch of 10,000 pounds, the same to test 8.00 per cent of fat, 12.50 per cent of milk S. N. F., .50 per cent of gelatin, 13.00 per cent of sugar, making 34.00 per cent T. S. Solution Problem 26, Example 27: (1). To calculate the pounds of fat, M. S. N. F. and gelatin required. 10000 X. 08=800, pounds of fat required. lOOOOX. 125=1250, pounds M. S. N. P. required. 10000X.005=:50, pounds gelatin required. (2). To calculate the pounds of butter required. 3400X. 04=136.00. pounds of fat in whole milk. 800—136=664.00, pounds of fat to be supplied by the butter. 664^.80=790.5, pounds of butter required. (3). To calculate the pounds of skim-milk powder required. 3400X. 085=289.00, pounds of M. S. N. F. in whole milk. 1360X. 087=118.32, pounds of M. S. N. F. in skim-milk. 1300X. 25=325.00, pounds of M. S. N. F. in condensed whole milk. lOOOOX. 005=50.00, pounds of gelatin required. 289.00+118.32+325.00=732.32, pounds of M. S. N. F. in four products to be added. Calculation of Water 315 1250—732.32=517.68, pounds of M. S. N. F. to be provided. 517.68-^.95=544.68, pounds of skim-milk powder to use. 4. To Calculate the Pounds of Sugar Required. lOOOOX -13=1300, pounds of sugar. 5. To calculate the pounds of water required. 3400+1360+1300+50+790.50+544.68+1300=8745.18 pounds of materials in mix. 10000—8745.18=1254.82 pounds of water required. The complete batch after standardizing to approximate tests will contain the following materials : Whole milk 3400.00 pounds Skim-milk 1360.00 pounds Plain condensed skim-milk 1300.00 pounds Butter 790.50 pounds Skim-milk powder 544.68 pounds Gelatin 50.00 pounds Sugar 1300.00 pounds Water 1254.82 pounds 10,000.00 pounds. The materials in the quantities as determined are mixed to- gether, homogenized and accurately sampled. The samples are immediately tested for fat and T. S. on the Mojonnier Tester. From the results obtained the final calculations are made to de- termine the materials to add in order to secure accurate stand- ardization. In making the calculation select and use the proper rule from those that follow in this chapter. When the percentage of fat or of M. S. N. F. in the mix are below the desired per- centage it is much more difficult to determine the exact amount of materials to add for correction, than it is to calculate the ma- terials to add when the fat and M. S. N. F. are present in excess. For this reason the aim should be always to have a small excess of fat and M. S. N. F. in the mix when this is made up before it is tested by the Mojonnier Tester for final accurate standard- ization. 316 Ice Cream Mixes Providing- Factor of Safety. In all problems given in this chapter the calculations are made upon the basis of an absolute standard. A proper factor of safety should be allowed, and it is recommended that this be about .10 per cent upon the fat and .20 per cent upon the T. S. STANDARDIZING ICE CREAM MIX. Problem 27. How to calculate when making a definite weight of mix using a vacuum pan. Solution of Problem 27, Based Upon Rule 24 : (1). Multiply the pounds of mix desired by the percentage of M. S. N, F. desired. Divide the answer by the percentage of M. S. N. F. desired The answer will be the pounds of whole milk required. (2). Multiply the pounds of mix desired by the percentage of fat desired. Subtract from this product the pounds of fat in the whole milk, and divide the remainder by the percentage of fat in the butter. The answer will be the pounds of butter required. (3). Multiply the pounds of mix desired by the percentage of water free gelatin desired and divide the product by the percentage of T. S. in the gelatin. The answer will be the pounds of gelatin required. Multiply the pounds of mix desired by the percentage of sugar desired. The answer will be the pounds of sugar required. Solution of problem 27, based upon formula 24 : (1). To calculate the pounds of whole milk required. M- XB (2). To calculate the pounds of butter required. (M^- X A)— (P^ X E^) (3). To calculate the pounds of gelatin and of sugar required. M- XBi U = MXV Calculation of Whole Milk and Butter Problem 27, Example 28. 317 Per Cent Products Fat M. S. N. F. Gelatin Sugar T. S. Whole milk 3.75 8.50 12.25 Butter 84.00 84.00 Gelatin 84.00 84.00 Sugar 100 100.00 Composition of mix de- sired 8.00 12.50 .50 13.00 34.00 It is desired to make 10,000 pounds of ice cream of the above tests, using the materials named. Solution of Problem 27, Example 28, based upon rule 24. (1). To Calculate the Pounds of Whole Milk Required. lOOOOX. 125=1250, pounds of M. S. N. F. required. 1250— :-.085=: 14706, pounds of whole milk required. (2). To Calculate the Pounds of butter Required. lOOOOX. 08=800.00 pounds of fat required. 14706 X. 0375=551.48, pounds of fat in whole milk. 800.00—551.48=248.52, pounds of fat to be provided from "" butter. 248.52-f-.84=295.90, pounds of butter required. (3). To Calculate the Pounds of Gelatin and Sugar Required. 10000 X .005 = 60, pounds gelatin required. 10000 X. 13=1300, pounds of sugar required. Condense the above batch to such a concentration as to obtain 10000 pounds of finished product. Solution of Problem 27, Example 28, based upon formula 24: (1). To calculate the pounds of whole milk required: P-=10000 X .125 .085 = 14706 (2). To calculate the pounds of butter required. 0^ ( 10000 X. 08 )— (14706 X -0375) ^ — ^ -=295.90 .84 318 Ice Cream ]\Iixes 3). To calculate the pounds of gelatin and of sugar required. S-=10000X.005 :60 .84 U=10000X. 13=1300 Proof of Problem 27, Example 28 : Products Pounds Total Fat M.S.N.F. Gelatin Sugar T. S. Whole milk 14706 5.51.48 1250.0 1801 48 Butter 296.0 248.52 248.52 Gelatin 60.0 60.0 50.0 Sugar 1300 1300 1300.0 Total pounds of batch after condensing and stand- 10000 800.00 1250.0 60.0 1300 3400.0 Products Per Cent Fat M.S. N. F. Gelatin Sugar T. S. Whole milk 3.75 8.50 12.25 Butter 84.00 84.00 Gelatin 84.00 84.00 Sugar 100.00 100.00 Tests of batch after cond standardizing ensing and 8.00 12.50 .50 13 00 34.00 Problem 28. How to Calculate When Making an Indefinite Weight of Mix Using a Vacuum Pan. Solution of Problem 28, Based Upon Rule 25 : (1). Multiply the pounds of whole milk by the percentage of M. S. N. F. in the whole milk. Divide the answer by the per- centage of M. S. N. F. desired. Call the answer A, or the pounds of mix possible to make from the whole milk on hand. Multiply A by the percentage of fat desired. Subtract from the answer the pounds of fat in the whole milk, and divide the remainder by the percentage of fat in the butter. The answer will be the pounds of butter required. (2). Multiply A by the percentage of w^ater free gelatin de- sired and divide the product by the percentage of T. S. in the gelatin. The answer will be the pounds of gelatin required. Multiply A by the percentage of sugar desired. The answer will be the pounds of sugar required. Weight for Vacuum Pan 319 Solution of Problem 28, based Upon Formula 25: (1). To calculate the pounds of butter required. 0^= l(^)-l ■(P^XE^) E^ (2). To calculate the pounds of gelatin and of sugar required. K^XB^ v^ U=KiXV Problem 28, Example 29. Pounds Per Cent Products Fat M. S. N. F. Gelatin Sugar T. S. Whole milk 10,000 3.75 8.50 12.25 Butter 84.00 84.00 Gelatin 84.00 Sugar 100.00 100.00 Composition of mix- desired, including gelatin 8.00 12.00 .50 13.00 33.50 It is desired to make all the ice cream mix possible from the above whole milk, using butter to supply extra fat required. Solution of Problem 28, Example 29, Based Upon Rule 25 : (1). To calculate the pounds of butter to use. lOOOOX. 085=850, pounds of M. S. N. F. in whole milk. 850-f-.12=7083, pounds of mix possible to make. 7083 X. 08=567, pounds of fat required. lOOOOX. 0375=375, pounds of fat in the whole milk. 567 — 375=192, pounds of fat to be provided by butter. 192^-.84=228, pounds of butter required. (2). To calculate the pounds of gelatin and of sugar required. 7083 X. 005=35.4, pounds water free gelatin required. 35.4-^-.84=42.0, pounds of gelatin required. 7083 X. 13=921, pounds of sugar required. 320 Ice Cream Mixes Solution of Problem 28, Example 29, Based Upon Formula 25 : (1). To calculate the pounds of butter required. 0.K 10000 X .085) J2 \ xt-otI X 7.07 1 — (10000 X .0375) .84 228 (2). To calculate the pounds of gelatin and of sugar required. 7083 X. .005 U=7083X. 13=921 Condense the above batch to such a concentration as to obtain 6800 pounds of finished product. Proof of Problem 28, Example 29 : Products Pounds Total Fat M.S. N.F. Sugar Total Whole milk 10000 375 850 1225 Butter 228 192 192 Gelatin 42 35 Sugar 921 921 921 Hotal pounds of batch 708:? 567 850 921 2373 Products Per Cent Fat M.S. N.F. Gelatin Sugar T. S. Whole milk 3.75 8.50 12.25 Butter 84.00 84.00 Gelatin .50 84.00 Sugar 13.00 100.00 Tests of batch 8.00 12.00 .50 13.00 33.50 PROBLEM 29: HOW TO CALCULATE WHEN THE FAT IS UNDER AND THE T. S. OVER THE STANDARD DESIRED. ALSO WHEN BOTH THE FAT AND THE T. S. ARE OVER THE STANDARD DESIRED, BUT WITH THE FAT IN A LOWER RATIO THAN THE T. S. See problem 30 for solution of second half of this problem. Cream sugar and water are to be used in standardizing. Solution of Problem 29, Based Upon Rule 26. (1). Divide the percentage of M. S. N. F. in the mix by the desired ratio between the fat and the M. S. N. F., and from the result, subtract the percentage of fat in the mix. Multiply the Calculation of Cream 321 difference by the pounds of mix. Call the product L. Divide the percentage of M. S. N. F. in the cream by the desired ratio between the fat and the M. S. N. F., and subtract the result from the percentage of fat in the cream to be used for standardizing. Call the result E. Divide L by E. The quotient equals the pounds of cream to be added to the mix to bring the fat and the M. S. N. F. to the desired ratio. (2). Multiply the pounds of mix by the percentage of M. S. N. F. in the mix, and multiply the pounds of cream required by the percentage of M. S. N. F. in the cream. Divide the sum of the two products by the weight of the mix plus the weight of the cream. From the quotient subtract the percentage of M. S. N. F. desired in the mix. Multiply this difference by the pounds of mix plus the pounds of cream required, and divide the product by the desired percentage of M. S. N. F. in the mix. The quotient equals the pounds of mix short after adding the cream. (3). Add the pounds of cream required to the pounds of mix short, and multiply the sum by the percentage of sugar in the mix. The result equals the pounds of sugar to add. (4). Subtract the pounds of sugar from the pounds of mix short after adding the cream. The difference equals the pounds of water required. Solution of Problem 29, Ba^ed Upon Formula 26 : (1), To calculate the pounds of cream to add: °=l"Ki)-]-l(Ms)] (2). To calculate the pounds of mix short after adding the cream. N^=(MXN) + (0XD) Then K=(N^— B)M^ M^^ B ^ (3) . To calculate the pounds of sugar to add. U=(K— 0)XV (4). To calculate the pounds of water required. 322 Ice Cream Mixes Problem 29, Example 30. Pounds Per Cent Products Fat M. S. N. F. Sugar T. S. Mix before standard- izing 10000 7.79 13.80 13.00 34.59 40.00 5.20 45.20 Sugar 100.00 100 . 00 Composition mix de- sired 8.00 13.00 13.00 34.00 Ratio of fat to M. S. N. F. desired 1 to 1.625. Mix before standardizing contains .50 per cent of gelatin which is included with the M. S. N. F. Solution of Problem 29, Example 30, Based upon Rule 26 : (1). To calculate the pounds of cream to add. 13.80-4-1.625=8.49, per cent of fat necessary to equalize M. S. N. F. in unstandardized mix. 8.49— 7.79=. 70, per cent of fat short. lOOOO.OOX. 007=70.00, pounds of fat short. 5.20^1.625=3.20, per cent of fat to equalize the M. S. N. F. in the cream. 40.00 — 3.20=:36.80, per cent of fat in the cream available for standardizing. 70.00-^-.368r= 190.22, pounds of cream required. (2). To calculate the pounds of mix short after adding the cream. lOOOOX. 138=1380.00 pounds of M. S. N. F. in the mix. 190.22X. 052=9.89, pounds of M. S. N. F. in the cream. 1380.00+9.89=1389.89, pounds of M. S. N. F. in the mix and cream together. 1389.89^-10190.22=13.64, per cent of M. S. N. F. in the mix and cream together. 13.64— 13.00=. 64, per cent excess M. S. N. F. in mix after adding the cream. 10190.22X.0064=65.12, pounds of excess M. S. N. F. 65.12-f-.13=500.88, pounds of mix short. (3). To calculate the pounds of sugar to add: 500.88+190.22=691.08, pounds of mix short plus pounds of cream. Calculation of Shortage 323 691.08 X. 13=89.84, pounds of sugar to add. (4). To calculate the pounds of water required. 500.88 — 89.84=411.04, pounds of water required. Solution of Problem 29, Example 30, Based Upon Formula 26. (1). To calculate the pounds of cream to add. = [l0000x(j5)-7.79)] = 190.22 (2). cream. To calculate the pounds of mix short after adding the N' (10000X.138) + (190.22X.052; K: 10190.22 (.1364— .13)X10190.22 l3 13.64 =50. (3). To calculate the pounds of sugar to add. U= (500.88+190.22) X.13=89.84 (4) . To calculate the pounds of water required. W=:500.88— 89.84=411.04 Proof of Problem 29, Example 30 : Pound Per Cent Materials in Batch Fat Milk S. N. F. Sugar Fat Milk S. N. F. Sugar T. S. Mix before standardizing . 10000 779.00 1380 1300 7.79 13.80 13.00 34.59 Cream added 190 76.00 10.00 40.00 5.20 45.20 90 90 100.00 411 Total after standardizing . 10691 855 . 00 1390 1390 8.00 13.00 13.00 34.00 PROBLEM 30. HOW TO CACULATE WHEN BOTH THE FAT AND THE T. S. ARE OVER THE STANDARD DESIRED, BUT WITH THE FAT IN A LOWER RATIO THAN THE T. S. This problem is very similar to problem 29, but for the sake of clarity its complete solution is here given. Cream, sugar and water are to be used in standardizing. 324 Ice Cream Mixes Salution of Problem 30, Based Upon Rule 27 : (1). Divide the percentage of M. S. N. F, by the desired ratio between the fat and the M. S. N. F, and from the quotient subtract the percentage of fat in the mix. Multiply the difference by the pounds in the mix. Call the product L, or pounds of fat short. Divide the percentage of M. S. N. F. in the cream by the desired ratio between the fat and the M. S. N. F. and subtract the quotient from the percentage of fat in the cream. Call the difference E., or the percentage of fat available in the cream for standardizing. Divide L by E., and call the quotient 0, or the pounds of cream required. (2). Multiply the pounds in the original mix by the per- centage of fat that it contains, and multiply the pounds of cream by the percentage of fat in it. Add the two products together and divide the sum by the number of pounds in the mix after adding the cream. From the quotient subtract the desired per- centage of fat, and multiply the difference by the pounds of original mix plus the pounds of cream required. The product thus obtained, divided by the desired percentage of fat in the mix, equals the pounds of mix short after adding the cream. (3). Add the pounds of cream required to the pounds of mix short and multiply the sum by the percentage of sugar desired. The product equals the pounds of sugar required. (4). Subtract the pounds of sugar from the pounds of mix short. The difference equals the pounds of water to add. Solution of Problem 30, Based Upon Formula 27: (1). To calculate the pounds of cream required. = [Mx(i)-F].[c-Q] (2). To calculate the pounds of mix short after adding- the cream. r(MxF) + (OxC) 1 ^- iSyTTcr -AJx(M+o ) A (3). To calculate the pounds of sugar required, TJ=(K+0)V Calculation oi^ Cream 325 (4). To Calculate the Pounds of Water Required. W=K— U Problem 30, Example 31 : Pounds Per Cent Products Fat M. S. N. F. Sugar T. S. Mix 10,000 8.10 13.70 13.00 34.80 Cream 40.00 5.20 45.20 Sugar 100.00 Water Desired composition 8.00 13.00 13.00 34.00 Mix before standardizing contains .50 per cent of gelatin which is included with the M. S. N. F. Solution of Problem 30, Example 31, Based Upon Rule 27: (4). To calculate the pounds of cream required. 13.70^1.625=8.43, per cent of fat to equalize the M. S. N. F. 8.43—8.10^.330, per cent of fat short. lOOOO.OOX. 0033=33.00, pound of fat short. 5.20-f-l. 625^3. 20, per cent fat required to equalize the M. S. N. F. in the cream. 40.00 — 3.20:=36.80, per cent fat in the cream available for standardizing. 33.00-^.368:=89.86, pounds of cream required. (2). To calculate the pounds of mix short after adding" the cream. lOOOOX. 081=810.0, pounds of fat in the mix. 89.86X.40=35.95, pounds of fat in the cream. 810.00+35.946=845.95, pounds of fat in the mixture. 10000+89.86=10089.86, pounds of mix and cream. 845.95^10089.86=8.384, per cent of fat in the mixture. 8.384—8.0=0.384, per cent fat excess. 10089.86X. 00384=38.745, pounds of fat excess. 38.745^.08=484.3, pounds of mix short after adding the cream, 326 Ice Cream Mixes (3) . To calculate the pounds of sugar. 484.34 89.86=574.16, pounds of mix short plus pounds of cream. 574.16X -13=74.64, pounds of sugar required. (4). To calculate the pounds of water required. 484.3 — 74.64r=409.66, pounds of water required. Solution of Problem 30, Example 31, Based Upon Formula 27 : (1). To calculate the pounds of cream required. riooooxr^^"^— -osil n=l \l.625j J [-{ri)l = 89.86 (2). To calculate the pounds of mix short after adding the cream. ■(10000 X.081) + (89.86 X.40) K = 10000 + 89.86 '1 081 X 10000 + 8986) = 484.3 .08 (3). To calculate the pounds of sugar required. U= (484.3+89.86) X. 13=74.64 (4). To calculate the pounds of water required. W=484.30— 74.64=409.66 Proof of Problem 30, Example 31 : Materials Pounds Per Cent Batch Fat M.S.N.F. Sugar T. S. Fat M.S.N.F. Sugar T. S. Mix 10000 810.0 1370. 1300 3480.0 8.10 13.70 13.00 34.80 90 36.0 5.00 71.0 40.00 5.20 45.20 Sugar 75 75. 75.0 100.00 100,00 Water 409 After standard- izing 10574 846 1375 1375 3596 8.00 13.00 13.00 34.00 PROBLEM 31: HOW TO CALCULATE WHEN THE FAT AND THE M. S. N. F. ARE BOTH UNDER THE STANDARD DESIRED. Butter, skim-milk powder and sugar are to be used for standardizing under this problem. Example 32 shows how to Steps in Calculation 327 solve this problem when using these products. Concentrated cream and condensed whole milk can also be used, as indicated by the solution under problem 32. Two methods of calculation are possible when using concen- trated cream and condensed whole milk. The second method as indicated under example 34 was originated by J. A. Cross. Solution of Problem 31, Based Upon Rule 28 : (1). Subtract the percentage of fat in the mix from the per- centage of fat desired, and multiply the difference by the weight of the mix. Divide the product by the percentage of fat in the butter. The quotient will be the pounds of butter required. (2). Subtract the percentage of M. S. N. F. in the mix from the percentage of M. S. N. F. desired, and multiply the difference by the weight of the mix. Divide the answer by the percentage of T. S. in the skim-milk powder. The answer will be the pounds of skim-milk powder required. (3). The pounds of butter plus the pounds of skim-milk powder multiplied by the percentage of sugar required equals the pounds of sugar required. The pounds of butter plus the pounds of sugar plus the pounds of milk powder equals the total weight of material to be added for standardizing. (4). Another calculation is necessary to standardize the ma- terial added which itself requires to be standardized. Multiply the total weight of material added for standardizing b}' the per- centage of fat desired, and divide the product by the percentage of fat in the butter. The result equals the pounds of butter required. (5). Multiply the total weight of material added for standard- izing by the percentage of M. S. N. F. desired and divide the product by the percentage of T. S. in skim-milk powder. The quotient equals the pounds of skim-milk powder required. (6). Multiply the total weight of materials added for stand- ardizing by the percentage of sugar desired. The product equals the pounds of sugar required. (7). The materials to be added under 3, plus the materials to be added under 4, 5, and 6, equals the total materials to be added in standardizing the batch. The batch will still not be 328 Ice Cream Mixes completely standardized because the products added under 5 and 6 require to be standardized also. An unstandardized remainder can thus be continued indefinitely, but the amount gradually becomes smaller and as a rule only one extra standardization is necessary. Solution of Problem 31, Based Upon Formula 28: (1) . To calculate the pounds of butter required. [MX(A-F)] O - J,: (2). To calculate the pounds of skim-milk powder required. [MX(B-N)] (3) . To calculate the pounds of sugar required. To calculate the extra pounds of each material necessary to standardize the material added in the first standardization. (4). To calculate the pounds of butter required, second standardization. ^,^_KO^+S^+U) A] (5). To calculate the pounds of skim-milk powder required, second standardization. '^- S (6). To calculate the pounds of sugar required, second standarization. Note: In the second standardization the factors 0^, S^ and U in the formula to the right of the equality sign represent the pounds of butter, skim-milk powder, and sugar respectively, as determined in the first standardization. Calculation of Products Problem 31, Example 32. 329 Pounds Per Cent Products Fat M. S. N. F. Sugar T. S. Mix 10,000 7.60 12.10 13,00 32.70 Butter 80,00 80.00 Skim-milk powder 95.00 95.00 Sugar 100.00 100.00 Composition desired 8.00 13.00 13.00 34.00 Desired ratio of fat to M. S. N. F. in the mix is 1 to 1.625. Mix before standardizing contains .50 per cent gelatin which is included with the above M. S. N. F. Solution of Problem 31, Example 32, Based Upon Rule 28 : (1). To calculate the pounds of butter required. 8.00— 7.60:^.40, per cent of fat short. lOOOO.OOX. 004=40, pounds of fat short. 40.00-f-.80:=:50, pounds of butter required. (2). To calculate the pounds of skim-milk powder required. 13.00— 12.10=:.90, per cent of M. S. N. F. short. 10000 X. 009 r= 90, pounds of M. S. N. F. short. 90-^.95^94.74, pounds of skim-milk powder short. (3). To calculate the pounds of sugar required. 50-f 94.74r=144.74, pounds of butter and skim-milk powder required. 144.74X -13=18.82, pounds of sugar required. To calculate the extra pounds of each material necessary to standardize the material added in the first standardization. (4). To calculate the pounds of butter required. 50-f 94.74+18.82=163.56, pounds of material added. 163.56 X. 08=13.08, pounds of fat required. 13.08-f-.80=:16.36, pounds of butter required. (5) . To calculate the pounds of skim-milk powder required. 50+94.74+18.82=163.56, pounds of material added. 163.56X.13=21.26, pounds of M. S. N. F. required. 21.26-^.95=22.40, pounds of skim-milk powder required. 330 Ice Cream Mixes (6). To calculate the pounds of sugar required. 50+94.74+18.82rrrl63.36, pounds of material added. 163.36X -13=21.26, pounds of sugar required. (7). To calculate total pounds of each material required. 50-fl6.36=66.36, pounds of butter required. 94.74+22.40=117.14, pounds of skim-milk powder required. 18.82+21.26=40.08, pounds of sugar required. Solution to Problem 31, Example 32, Based Upon Formula 28 : (1). To calculate the pounds of butter required. 10000X(.08— .076) 0= M =^« (2). To calculate the pounds of skim-milk powder required. 10000X(.13— .121) S^= ^ =94.74 .9.5 (3). To calculate the pounds of sugar required. U= (50+94.74) X.13=18.82 (4). To calculate the pounds of butter required, second standardization. (50+94.74+18.82) X.08 «■= Jo =''■'' (5). To calculate the pounds of skim-milk required, second standardization. (.50+94.74+18.82) X. 13 S^= g^ — — =22.40 (6). To calculate the pounds of sugar required, second standardization. U= (50+94.74+18.82) X.1300=21.26 The addition of butter and skim-milk powder is not practicable unless they can be added before the batch is pasteurized and homogenized. Fat and T. S. Under Standard 331 Proof of Problem 31, Example 32. Products Pounds Per Cent Fat M.S.N.F. Sugar T.S. Fat M.S.N.F. Sugar T.S Mix 1000 760.00 1210.0 1300 3270 7.60 12.10 13.00 32.70 Butter 66.36 53.08 80.00 80 00 Skim-milk 117.14 105.7 105.7 95.00 95.00 40.08 40.08 100.00 100 00 Standardized products 10223.00 813.08 1315.7 1340.08 3375.7 7.95 12.90 13.11 33.96 PROBLEM 32: HOW TO CALCULATE WHEN THE FAT AND T. S. ARE BOTH UNDER THE STANDARD DESIRED. Solution of problem 32, based upon rule 29. Under this modification of problem 31, the use of concentrated cream and condensed whole milk is contemplated in effecting standardization. (1). Subtract the percentage of fat desired from the per- centage of fat in the mix. Multiply the remainder by the pounds of mix. Call the answer A. Divide the percentage of M. S. N. F. in the cream by the ratio between the fat and the M. S. N. F. desired and subtract the answer from the percentage of fat in the cream. Divide A by the remainder. The answer will be the pounds of cream required. (2). Multiply the pounds of cream required and the pounds of mix by their respective percentages of M. S. N. F. and add the two products together. Divide the sum by the combined pounds of mix and cream required. The answer will be the percentage of M, S. N. F. in the mixture. (3). Subtract the percentage of M. S. N. F. in the mixture from the percentage of M. S. N. F. desired and multiply the combined pounds of mix and cream by the remainder. Call the product B, or the pounds of M. S. N. F. short. Multiply the per- centage of fat in the condensed milk by the ratio, and subtract the answer from the percentage of M. S, N. F. in the condensed milk. Divide B by the remainder. The answer will be the pounds of condensed milk required. (4), Multiply the pounds of cream and condensed milk used by the percentage of sugar desired to obtain the pounds of sugar required. 332 Ice Crp^am Mixes Solution of Problem 32, Based Upon Formula 29 : (1). To calculate the pounds of cream required to supply the fat short in the mix. o=[;axf)xm]^[c-(?)] (2). To calculate the percentage of M. S. N. F. in the mix after adding the cream. (0XD) + (MXN) N^ (0+M) (3). To calculate the pounds of condensed milk required after adding the cream. H^^ (B— NO X (M+0)-^-[F^X (C^XR) ] (4). To calculate the pounds of sugar required. U=(0+HOV. Problem 32, Example 33 : Products Pounds Per Cent Fat M. S. N. F. Sugar T. S. Mix 10,000 7.60 12.70 13.00 33.30 Cream 40.00 6.00 46.00 Condensed milk 10.50 25.50 36.00 Composition desired 8.00 13.00 13.00 34.00 Desired ratio of fat to M. S. N. F. is 1 to 1.625. Mix before standardizing contains .50 per cent of gelatin which is included with the above M. S. N, F. Solution of Problem 32, Example 33, based Upon Rule 29 : (1). To calculate the pounds of cream required to supply the fat short in the mix. 8.00— 7.60r=.40, per cent of fat short. lOOOOX. 004=40, pounds of fat short. Cai,cui.ations 333 6.00-^-1.625=3.70, per cent of fat to equalize the M. S. N. F. in the cream. 40.00—3.70=36.30, per cent of fat available for standard- izing in the cream. 40h-.363=110.2, pounds of cream required. (2). To calculate the percentage of M. S. N. F. in the mix after adding the cream. 110.2X. 06=6.61, pounds of M. S. N. F. in the cream. lOOOOX. 127=1270, pounds of M. S. N. F. in the original mix. 1270+6.12=1276.12, pounds in both. 10000-f 110.2=10110.2, pounds of mix plus cream. 1276.12-^10110.2=12.62, per cent M. S. N. F. in the mix- ture. (3). To calculate the pounds of condensed milk required. 13.00— 12.62=.38, per cent of M. S. N. F. short. 10110.2X. 0038=38.4, pounds of M. S. N. F. short. 10.50X1.625=17.06, per cent of M. S. N. F. to equalize the fat in the condensed milk. 25.5—17.06=8.44, per cent of M. S. N. F. available for standardizing in the condensed milk. 38.40-H-.0844=443, pounds of condensed milk required. (4). To calculate the pounds of sugar required 443-|-110.2=553.2, pounds of cream and condensed milk, 553, 2 X. 13=73, pounds of sugar required. Solution of Problem 32, Example 33, Based Upon Formula 29: (1). To calculate the pounds of cream required to supply the fat short in the mix. [(8.00— 7.60) X 10000] 0=^^^ ^=110.2 [^^•««-(S] (2) . To calculate the percentage of M. S. N. F. in the mix after adding the cream. (110,2X6.00) -f- (10000X12.70) N^rz^ 19 fi9 [10000+110.2] —L'i.O^ 334 Ice Cream Mixes (3). To calculate the pounds of condensed milk required after adding the cream. (.1300X.1262) X (10000—110.2) H^ .255X (.105X1.625) (4). To calculate the pounds of sugar required. U= (110.2+443) X.13^73.00 Proof of Problem 32, Example 33 : 443 Products Pounds Per Cent Fat M S.N.F Sugar T.S. Fat M.S.N.F. Sugar T.S Mix 10000 760.00 1270 1300 3330 7.60 12.70 13.00 33.30 Cream 110.2 44.08 6.12 50.2 40.00 6.00 46.00 Condensed whole milk 443.0 46.51 112.96 159.47 10.50 25.50 36.00 Sugar 73.0 73 73.00 100.00 100.00 Standardized product 10626.2 850.59 1389.08 1373 3612.67 8.00 13.07 12.92 33.00 The above method of standardization does not give results that check out exactly, as the proof indicates. PROBLEM 33: HOW TO CALCULATE WHEN THE FAT AND THE M. S. N. S. ARE BOTH UNDER THE STANDARD DESIRED. The problem is the same as problems 31 and 32. As in the ease of these problems the use of concentrated cream and con- densed skim-milk or of butter and skim-milk powder is contem- plated in effecting standardization. The method of calculation shown under this problem is that originated by Jos. A. Cross. This method of calculation can be used upon problem 33, and also in the case of problems in which either the fat or T. S. are correct, but one or the other are low. Principles of Cross Method of Calculation. This method is based upon making the calculations for two theoretical mixtures of dairy products from materials on hand available for standard- izing. Mixture No. 1, to contain an excess of fat available for standardizing. Mixture No. 2, to contain an excess of M. S. N. F. available for standardizing. If the tests of the materials on hand are known, these calculations can be made before testing Rectangle Method 335 the mix that is to be standardized, thereby saving time in making the final calculations. It is not necessary to make the actual mixtures of materials. The materials can be added in the pro- portions found necessary by the calculations. This method merits close study, and it is highly recommended since it gives abso- lutely accurate results all in one calculation. How to Calculate Theoretical Mixtures No. 1, in which the M. S. N. F. is Standard and the Fat is Above Standard. When standardizing material is added to a batch of ice cream mix, a proportionate amount of sugar must be incorporated in order to produce no change in the sugar content of the standardized batch. If a mix tests 14.94 per cent of M. S. N. F. without sugar, it will test 13 per cent of S. N. F. after the correct amount of sugar is added in the case of a mix testing 8.00 per cent of fat, 13.00 per cent of M. S. N. F. and 13.00 per cent of sugar. This is found by subtracting 13.00 per cent of sugar from 100.00 and dividing 13.00 per cent of M. S. N. F. by 87. Likewise this mix will contain 9.20 per cent of fat found by dividing 8.00 per cent by 87. The fol- lowing mix is calculated to test 14.94 per cent of M. S. N. F. Materials to be used. Condensed skim-milk testing .50 per cent fat, 25.00 per cent S. N. F. and cream testing 40.00 per cent fat, 5.34 per cent M. S. N. F. Use Dr. Pearson's method for mak- ing the calculation, and calculate the percentage of fat available for standardizing in the mixture, as follows : Cond. skim-milk=25.00 ' 9.60 Cream=5.34 10.06 10.06-|-9. 60= 19.66, sum of condensed skim-milk and cream units to use. 9.60-^-19.66^48.80, per cent of condensed skim-milk. 10.06-^19.66=51.20, per cent of cream. 51.2 parts of cream=20.46 parts of fat and 2.74 parts of M. S. N. F. 48.80 parts of condensed skim-milk=.24 parts of fat and 12.20 parts of M. S. N. F. 336 let Cream Mixes 100.0=20.70 parts of fat, 14.94 parts of M. S. N. F. 20.7 — 9.20=11.50, available per cent of fat in the mixture which can be used for standardizing. As calculated above, a mixture of 48.8 parts of 40 per cent cream and 51.2 parts of 25 per cent condensed skim-milk will test 14.94 per cent in solids not fat, which will be reduced to 13 per cent after the proper amount of sugar is added to the mix. Any desired amount of this mixture may be added to a batch of ice cream mix testing 13 per cent S. N. F. without changing S. N. F. test of the standardized mix. It tests, however, 11.50 per cent higher than standard in butter fat and every 100 pounds added (plus 14.94 pounds of sugar) will make up a deficit of 11.5 pounds of fat in the mix to be standardized and will leave the percentage of M. S. N. F. and the percentage of sugar unchanged. It is, of course, unnecessary to actually make up this mixture. If the tests of the mixture to be standardized shows that it is standard in M. S. N. F. but requires 11.5 pounds of fat, add 48.8 pounds of the condensed and 51.2 pounds of 40 per cent cream and 14.94 pounds of sugar. If the deficit is 23 pounds of fat add twice the above amounts etc. Other combinations using cream of different percentages and condensed milk of different concentration may be calculated and a record of the proportions necessary should be kept on file. These combinations may be made to cover any composition of mix de- sired. A few combinations of commonly used standardizing materials are given in Table 60. These are all based upon a mix contain- ing 8.00 per cent fat, 13.00 per cent of M. S. N. F., 13.00 per cent of sugar, making 34.00 per cent T. S. All of them will test 14.94 per cent of solids not fat and will have fat in excess and avail- able for standardizing as indicated. How to Calculate Theoretical Mixture No. 2 in Which the Fat is Standard and the M. S. N. F. is Above Standard. The calcula- tion of this mixture is the same as in the case of mixture No, 1 except that it is made standard in fat, and used to raise the M. S. N. F. test of the mix to be standardized. In order to test 8.00 per cent of fat after sugar is added the mixture must test 9.20 per cent before adding the sugar, if it is to contain 13.00 Various Combinations 337 per cent of sugar. Therefore, the following is calculated to test 9.20 per cent of fat and a« much above 14,94 per cent of M. S. N. F. as possible. Materials to be used — 40.00 per cent cream testing 5.34 per cent of M. S. N. F. and condensed skim-milk testing .50 per cent of fat, 25.00 per cent of M. S. N. F. TABLE 60 A few combinations of cream and condensed milk containing an excess of fat available for standardizing. Com- bination No. Cream Condensed Milk Parts Cream to Use Parts Condensed Milk to Use Percentage Fat in Mixture Available for Stand- ardizing. Per Cent Per Cent Fat M. S. N. F. Fat M. S. N. F. 1 20.00 7.12 .50 25.00 63.35 36.65 3.65 2 25.00 6.75 .50 25.00 55.12 44.88 4.80 3 30.00 6.23 .50 25.00 53.60 46.40 6.11 4 40.00 7.80 7.80 17.70 22.30 77.70 5.78 5 40.00 5.23 5.00 25.00 51.17 48.83 13.71 Use Dr. Pearson's method for making the calculation and calculate the percentage of M. S. N. F. available for standardizing in the mixture as follows : Cream=40.00 8.7 9.20 Cond. skim-milk 30.8 .50 8.7+30.8=39.5 8.70-f-.396=22, per cent of cream. 30.80-^.396=78, per cent of condensed skim-milk . 78 parts of condensed skim-milk contains .40 parts fat, 19.5 parts M. S. N. F. 22 parts of cream contains 8.80 parts fat, 1.17 parts M. S. N. F. 100 parts of the mixture contain 9.20 parts fat 20.67, parts M. S. N. F. 338 Ice Cream Mixes 20.67—14.94=5.73, per cent of M. S. N. F. above standard and available for raising the M. S, N. F. test of low testing ice cream mix. As calculated above, a mixture of 78 parts of condensed skim- milk and 22 parts of cream will make a mix testing standard in fat, after 14.94 pounds of sugar is added per hundred. It will test, however, 5.73 per cent higher in M. S. N. F. than standard and therefore every hundred pounds added to an ice cream mix (with the proper amount of sugar) will make up a deficit of 5.73 pounds of M. S. N. F. without changing either the fat or the sugar test of the final mix. Other combinations of dairy products with different tests are given in Table 61. Each will test standard in fat but will have an excess of M. S. N. F. as indicated. TABLE 61 A few combinations of dairy products, containing an excess of M. S. N. F. available for standardizing. Cream Condensed Milk Parts of Cream to Use Parts Condensed Milk to U.se Percentage Combi- nation Per Cent Per Cent M. S. N. F. in Mixture No. Fat M. S. N. F. Fat M. S. N. F. Available for Standardizing 6 20.00 7.12 .50 25.00 44.60 55.40 2.08 7 30.00 6.23 .50 25.00 29.50 70.50 4.52 8 40.00 5.34 7.80 17.70 4.35 95.65 2.22 9 40.00 5.34 5.00 25.00 12.00 88.00 7.70 10 Butter 83.00 Skim-mil 1.00 k powde 1.00 95.00 BUTTER 10.00 SKIM-MILK POWDER 90.00 69.66 Having calculated the theoretical mixtures Nos. 1 and 2, and calculated the available percentage of fat and M. S. N. F. respec- tively, it then becomes a simple matter to calculate the pounds of dairy products and sugar necessary to add to raise the test of the mix to the point desired. The method of calculation recommended is fully illustrated under example 34. Calculation of Fat Problem 33, Example 34: 339 Products Pounds Per Cent Fat M. S. N. F. Sugar T. S. Mix before standardizing 10,000 7.80 12.60 13.00 33.40 Cream 40.00 5.40 45.40 Condensed milk .50 25.00 26.00 Composition desired 8.00 13.00 13.00 34.00 Ratio of fat to M. S. N. F. desired is 1 to 1.625. Mix before standardizing contains .50 per cent gelatin which is included with the above M. S. N. F. Solution of Problem 33, Example 34, Based Upon Calculation only. (1). To calculate the fat, and M. S. N. F. to provide, when sugar is to be added after standardizing. Also to calculate the percentage of sugar necessary when this is added to the standard- ized mix. 100 — 13=87.00, per cent of total products in mix besides sugar. 8.00^.87=9.20, per cent of fat that the mix should eon- tain if sugar is to be added after standardizing. 13.00^.87=14.94, per cent of M. S. N. F. the mix should contain if sugar is to be added after standardizing. 13.00^.87=14.94, per cent of sugar to add to milk products only to yield a mix containing 13.00 per cent of sugar. (2). To calculate the fat available for standardjizing- in theoretical mixture No. 1. Condensed skim-milk=:25.00 Cream=5.40 9.54 14.94 10.06 340 Ice Cream Mixes 14.94 — 5.40=9.54, the units of condensed skim-milk to use. 25.00—14.94=10.06, the units of cream to use. 9. 54+10.06=19. 60, the sum of the condensed skim-milk and cream units to use. 9.54-^.196=48.67, the per cent of condensed skim-milk to use. 10.06-^.196:=51.33, the per cent of cream to use. 48.67 X -50=. 24, per cent of fat in mixture derived from condensed skim-milk. 51.33X -40=20.53, per cent of fat in mixture derived from cream. 20.53+.24=20.77, per cent of fat in mixture derived from both condensed skim-milk and cream. 20.77—9.20=11.57, per cent of fat in mixture No. 1, avail- able for standardizing. (3). To calculate the available M. S. N. F. in theoretical mixture No. 2. Cream 40.00 8.20 Condensed skim-milk 1.00 30.80 40.00 — 9.20=30.80, units of condensed skim-milk to use. 9.20—1.00=8.20, units of cream to use. 8.20+30.80=39.00, the sum of the condensed milk and cream units to use. 30.80-f-.39=78.97, the per cent of condensed skim-milk required. 8.20-^.39=:21.03, the per cent of cream to use. 78.97 X. 25=19.74, the per cent of M. S. N. F. in the mixture derived from the condensed skim-milk. 21.03X.054=1.14, the per cent of M. S. N. F. in the mixture derived from the cream. 19.74+1.14=20.88, the per cent of M. S. N. F. in the mix- ture derived from both the condensed skim-milk and cream. Calculations 341 20.88—14.94=5.94, the per cent of M. S. N. F. in mixture No. 2 available for standardizing, (3). To calculate the pounds of fat short and the pounds of mixture No. 1 required to provide the pounds of fat short. 8.00— 7.80==. 20, the per cent of fat short. 10000 X.004=40, pounds of M. S. N. F. short. 20-^ .1157=173, pounds of mixture No. 1 required. (4). To calculate the pounds of M. S. N. F. short, and the pounds of mixture No. 2 required to provide the pounds of M. S. N. F. short. 13.00— 12.60=:.40, per cent of M. S. N. F. short. lOOOOX. 40=40, pounds of M. S. N. F. short. 40.00-=-.0594=675, pounds of mixture No, 2 required. (5). To calculate the pounds of cream and condensed skim- milk required under 3 and 4, also the extra sugar required. 173.x •5133:=88, 80, pounds of cream required from mixture No. 1. 674X. 2103=141, 53, pounds of cream required from mix- ture No. 2. 88.80+141.53=230.44, total pounds of cream required. 173X. 4867=84.20, pounds of condensed skim-milk required from mixture No, 1. 673X.7897=531.47, pounds of condensed skim-milk re- quired from mixture No. 2. 84,20+531,47=615.66, total pounds of condensed skim- milk required, 230.33+615,66=845.99, total pounds of cream and con- densed skim-milk required. 845.99 X -1494= 126.39, pounds of sugar required in stand- ardizing. Therefore add for standardizing: 230.33 pounds of 40.00 per cent cream. 615.66 pounds of 25.00 per cent condensed skim-milk. 109.98 pounds of sugar. 955.97 pounds total. 342 Ice; Cream Mixes Proof of Problem 33, Example 34 : Pounds Per Cent Fat M.S.N.F. Sugar T. S. Fat M.S.N.F. Sugar T. S Mix before standardizing 10000.00 780.00 1260.00 1300.00 7.80 12.60 13.00 33.40 230.00 92.13 12.44 40.00 5.40 45.40 Condensed 615.66 3.08 153.92 .50 25.00 26.00 Sugar 126.39 126 39 100.00 Mix after standardizing 10955.97 875.21 1426.36 1426.39 3727.96 8.00 13.00 13.00 34.00 PROBLEM 34: HOW TO CALCULATE WHEN THE FAT IS OVER AND THE M. S. N. F. OR THE T. S. UNDER THE STANDARD DESIRED. ALSO WHEN THE PERCENTAGES OF FAT AND M. S. N. F. OR T. S. ARE OVER THE STANDARD DESIRED BUT WITH THE FAT IN A HIGHER RATIO THAN THE T. S. Skim-milk powder, sugar and water are to be added for standardizing. The calculation in problem 33, example 34, can be applied to the solution of this problem. However, after getting the M. S, N. F. in the proper ratio to the fat, water is to be added to bring the mix back to the standard desired. Solution of Problem 34, Based Upon Rule 29 : (1). Subtract the percentage of fat desired from the per- centage of fat in the mix, and multiply the remainder by the weight of the mix. Divide the result by the percentage of fat desired. The quotient equals the pounds of mix short. (2). Multiply the percentage of fat in the mix by the ratio of fat desired to M. S. N. F. desired, and from the result subtract the percentage of M. S. N. F. in the batch. Multiply the re- mainder by the number of pounds in the batch, and divide the product by the percentage of M. S. N. F. in the skim-milk powder. The quotient equals the number of' pounds of skim-milk powder required. (3). Multiply the pounds of mix short by the percentage of sugar desired. The product equals the pounds of sugar required. (4). The number of pounds of sugar required plus the number of pounds of skim-milk powder required subtracted from the number of pounds of mix short equals the number of pounds of water to add. Calculations 343 Solution Problem 34, Based Upon Formula 29a : (1). To calculate the pounds of mix short. (F— A)XM K= — ^ — (2). To calculate the pounds of skim-milk powder required. (FXR)— NXM] 8^= S (3). To calculate the pounds of sugar required. U=KXV (4). To calculate the pounds of water required. W=M— (U— S^) Problem 34, Example 35 : Products Pounds Per Cent Fat M. S. N. F. Sugar T. S. Mix 10,000 8.24 12.70 13.00 33.94 Skim-milk powder 95.00 95.00 Suear 1,300 100. 100.00 Composition desired 8.00 13.00 13.00 34.00 Desired ratio of fat to M. S. N. F. is 1 to 1.625. Mix before standardizing contains .50 per cent of gelatin, which is included with the M. S. N. F. Solution of Problem 34, Example 35, Based Upon Rule 29 : (1). To calculate the pounds of mix short. 8.24— 8.00=. 24, per cent of excess fat. 10000 X. 0024=24, pounds of excess fat. 24-^.08=300, pounds of mix short. (2). To calculate the pounds of skim-milk powder required. 8.24X1.625=13.39, per cent of M. S. N. F. to equalize the fat in the batch. 13.39— 12.70=. 69, per cent of M. S. N. F. short. 10000X.0069=69, pounds of M. S. N. F. short. 69-^-.95=72.63, pounds of milk powder required. 344 Ice Cream Mixes (3). To calculate the pounds of sugar required. 300X-1300=r39, pounds of sugar required. (4). To calculate the pounds of water required. 72.63--j-39=:111.63, pounds of sugar and milk poAvder. 300 — 112=188, pounds of water required. Solution of Problem 34, Example 35, Based Upon Formula 29a ; (1). To calculate the pounds of mix short. (.0824— .0800) X 10000 K= ^^ =300 (2). To calculate the pounds of skim-milk powder required. [ (.0824X1.625)— .1270] XlOOOO Si=r ^ =72.63 .95 (3). To calculate the pounds of sugar required. U=300X. 13=39 (4). To calculate the pounds of water required. W=300— (72.63+39) =188 Proof of Problem 34, Example 35. Products Pounds Per Cent Fat M.S.N.F. Sugar T. S. Fat M.S.N.F. Su.?ar T. S. Mix 10000.00 824 1270 1300 3394 8.24 12.70 13.00 33.94 Skim-milk powder 72.63 69 69 95.00 95.00 39.00 39 39 100.00 100.00 Water 188 37 ' Standardized product 10300.00 824 1339 1339 3502 8.00 13.00 13.00 34.00 Note: No account was taken of the small amount of fat in the skim-milk powder used. The addition of skim-milk powder is not practicable unless this can be added to the batch at pasteurizing temperatures. Fat and M. S. N. F. Over Standard 345 PROBLEM 35: HOW TO CALCULATE WHEN THE PERCENTAGES OF FAT AND M. S. N. F. ARE BOTH OVER THE STANDARD DESIRED BUT WITH THE FAT IN A HIGHER RATIO THAN THE M. S. N. F. Skim-milk powder, sugar and water are to be added for standardizing. The calculation in problem 33, example 34, can be applied to the solution of this problem. However, after getting the M. S. N. F. in the proper ratio to the fat, water is to be added to bring the mix back to the standard desired. Solution of Problem 35, Based Upon Rule 30: (1). Subtract the percentage of fat desired from the per- centage of fat in the mix, and multiply the remainder by the pounds of mix. Divide the product by the percentage of fat desired in the mix and the result equals the pounds of mix short. (2). Multiply the percentage of fat in the batch by the ratio of fat to M. S. N. F., and subtract from the product the per- centage of M. S. N. F. in the batch. Multiply the remainder by the pounds in the batch and divide the product by the percentage of M. S. N. F. in the skim-milk powder. The quotient equals the pounds of skim-milk powder required, (3). Multiply the pounds of mix short by the percentage of sugar desired. The product equals the pounds of sugar required. (4). The pounds of sugar required plus the pounds of skim- milk powder required subtracted from the pounds of mix short equals the pounds of water required. Solution of Problem 35, Based Upon Formula 30 : (1). To calculate the pounds of mix short. (F— A)XM ^= A (2). To calculate the pounds of skim-milk powder required. [(FXR)-N]XM ^- S (3). To calculate the pounds of sugar required. U=KXV (4). To calculate the pounds of water required. W=K— (S^— U) 346 Icp: Cream Mixes Problem 35, Example 35: Products Pounds Per Cent Fat M. S. N. F. Sugar T. S. Mix 10,000 8.30 13.20 13.00 34.50 Skim-milk powder 95.00 95.00 Sugar 100.00 100.00 Composition desired 9.00 13.00 13.00 34.00 Desired ratio of fat to M. S. N. F. is 1 to 1.625. The mix before standardizing contains .50 per cent of gelatin which is included with the M. S. N. F. Solution of Problem 35, Example 36, Based Upon Rule 30. (1). To calculate the pounds of mix short. 8.30 — 8.00=. 30, per cent of fat in excess. 10000 X. 0030=30, pounds of fat in excess. 30-^.08=375, pounds of mix short. (2). To calcTilate the pounds of skim-milk powder required. 1.625X8.30=13.48, per cent of M. S. N. F. necessary to standardize the fat in the batch. 13.48— 13.20=.28, per cent of M. S. N. F. short. .0028X10000=28, pounds of M. S. N. F. short. 28-^.95^29.47, pounds of milk powder required. (3). To calculate the pounds of sugar required. 375 X -1300=48.75, pounds of sugar required. (4). To calculate the pounds of water required. 48.75-|-29.47=78.22, pounds of sugar and powder required. 375 — 78.22=296, pounds of water required. Solution of Problem 35, Example 36, Based Upon Formula 30 : (1). To calculate the pounds of mix short. (. 083 X. 080) X 10000 '^=- T8 =3'5 (2). To calculate the pounds of skim-milk powder required. (.083X1.625)-.132] XlOOOO S^= .95 :29.47 Fat and M. S. N. F. Over Standard 347 (3). To calculate the pounds of sugar required. U=375X.1300=48.75 (4). To calculate the pounds of water required. W=375— (29.47+48.75) r=296. Proof of Problem 35, Example 36. Products Pounds Per Cent Fat M.S.N.F. Sugar T.S. Fat M.S.N.F. Sugar T. S Mix 10000,00 830 1320 1300 3450 8.30 13.20 13.00 34.50 Skim-milk powder 29.47 28 28 95.00 95 00 Sugar 48.75 48.75 48.75 100.00 100 00 Water 296.00 Standardized product 10374.22 830 1348 1348 3526 8.00 13.00 13.00 34.00 PROBLEM 36: HOW TO CACULATE WHEN THE PERCENTAGES OF FAT AND M. S. N. F. ARE BOTH OVER THE STANDARD DESIRED MAKING IT NECESSARY TO ADD SUGAR AND WATER ONLY. Solution of Problem 36, Based Upon Rule 31 : (1). Subtract the percentage of fat desired from the per- centage of fat in the mix and multiply the pounds of mix by the difference. Divide the product by the percentage of fat desired. The answer will be the pounds of mix short. (2). Multiply the pounds of mix short by the per cent of sugar desired. The answer will be the pounds of sugar required. (3). Subtract the pounds of sugar required from the pounds of mix short. The ansAver wil be the pounds of water required. Solution of Problem 36, Based Upon Formula 31 : (1). To calculate the pounds of mix short. (F— A) M K=^ — (2). To calculate the pounds of sugar to add. U=KXV (3). To calculate the pounds of water required. W=rK— U "348 Ice Cre;am Mixes Problem 36, Example 37 : Products Pounds Per Cent Fat M. S. N. F. Sugar T. S. Mix 10,000 8.20 13.25 13.00 34.52 Sugar 100.00 100.00 Composition desired 8.00 13.00 13.00 34.00 Solution of Problem 36, Example 37, Based Upon Rule 31: (1). To calculate the pounds of mix short. 8.20 — 8.00=. 20, per cent of fat in excess. lOOOOX. 0020=20, pounds of fat in excess. 20-^.08=: 250, pounds of mix short. (2). To calculate the pounds of sugar required. 250X. 13=32. 50, pounds of sugar required. (3) . To calculate the pounds of water required. 2.50 — 32.50=217.5, pounds of water required. Solution of Problem 36, Example 37, Based Upon Formula 31 : (1). To calculate the pounds of mix short. (.082— .080) X 10000 J 1 K= .08 :250 (2). To calculate the pounds of sugar to add. U=250X.13=32.50 (3) . To calculate the pounds of water to add. W=250— 32.50=217.5 Proof of Problem 36, Example 37: Products Pounds Per Cent Fat M.S.N.F. Sugar T. S. Fat M.S.N.F. Sugar T.S. Mix 10000.00 820 1332.5 1300 3452.5 8.20 13.325 13.00 34.525 32.50 32.50 32.5 100.00 100.00 Water 217.60 Standardized product 10250.00 820 1332.5 1332.5 3485.0 8.00 13.00 13.00 34.00 Sweetened Condensed Skim-Milk 349 HOW TO CALCULATE WHEN USING SWEETENED CONDENSED SKIM-MILK IN ICE CREAM MIX. Sweetened condensed skim-milk can be used in the ice cream mix to furnish the entire sweetening necessary. The balance of the fat and M. S. N. F. can be made up by using cream or butter, and whole milk. Sweetened condensed skim-milk is an economi- cal substance to use. A good quality may be purchased from reliable firms and stored, and it will keep indefinitely. It also has the advantage of being very easy to use. It would un- doubtedly be used to a much greater extent than it is at present if manufacturers had formulas which would give good results when properly worked out. The method of calculation given herewith f.or using this prod- uct was originated largely by J. A. Cross. The average composition of sweetened condensed skim-milk is about 1.00 per cent fat, 28.00 per cent M. S. N. F. and 41.00 per cent sugar. All of these values are subject to fluctuations so that the actual test of the product should be ascertained. In these calculations it is assumed that the M. S. N. F. in skim-milk serum is 8.90 per cent. This can be found exactly for any product by subtracting the percentage of fat in the product from 100 and dividing the percentage of M. S. N. F. by the remainder. Example: Whole milk tests 3.75 per cent fat, 8.60 per cent M. S. N. F. Solution : 8.60 =8.93, or per cent of M.S.N.F. in skim-milk serum. (100.00—3.75) The above problem is solved herewith by rule, formula, and example. A new set of factors differing from those previously used in this chapter, are used in the formulas. KEY TO FACTORS IN FORMULAS FOR USING SWEETENED CONDENSED SKIM-MILK. A=:The percentage of sugar desired. B=The percentage of sugar in the sweetened condensed skim- milk. C=The pounds of sweetened condensed skim-milk necessary to provide the sugar required. 350 Ice Cream Mixes D=The percentage of M. S. N. F, in the sweetened condensed skim-milk. Er=The pounds of M. S. N. F. in the sweetened condensed skim-milk. F=The pounds of M. S. N. F. in the entire batch of mix. G=The average percentage of M. S. N. F. in skim-milk serum. H=:The pounds of skim-milk serum required. I r=:The pounds of fat required for the entire batch. J=The pounds of fat contained in the sweetened condensed skim-milk. K=The pounds of cream required. L=The percentage of fat in K. M=The percentage of fat in the whole milk. N=The percentage of fat in the butter. O^The pounds of butter required. prrzThe pounds of whole milk required. Q=The pounds of mix desired. R=rThe pounds of sugar required. S=:The percentage of M. S. N. F. desired. T=The percentage of fat required. U^The percentage of fat in sweetened condensed skim-milk. Problem 37. How to Calculate When Using Sweetened Con- densed Skim-milk in Ice Cream Mix. Solution of Problem 37, Based Upon Rule 32 : (1). To calculate the pounds of sweetened condensed milk necessary to furnish the sugar required. Multiply the pounds of mix desired by the percentage of sugar desired and divide by the percentage of sugar in the sweetened condnsed skim-milk. Call the answer A, or the pounds of sweetened condensed skim- milk required for the entire batch of mix to be made. (2). To calculate the pounds of skim-milk serum required. Multiply the pounds of mix desired by the percentage of M. S. N. F. desired, and subtract the answer from the pounds of M. S. N. F. in the sweetened condensed skim-milk required, found by multiplying the pounds of sweetened condensed skim- milk by the percentage of M. S. N. F. contained in the same. Call the remainder B, or the pounds of M. S. N. F. to be supplied by cream or whole milk. Divide B by 8.90 (the average M. S. Cai,cui,ations 351 N. F. test of skim-milk serum), and call the answer C, or the pounds of skim-milk serum required. (3). To calculate the pounds of cream required and the per- centag-e of fat in the same. Multiply the pounds of mix desired, by the percentage of fat desired. Subtract from the answer the pounds of fat in the sweetened condensed skim-milk found by multiplying the pounds of sweetened condensed skim-milk re- quired by the percentage of fat in the same. Call the answer D, or the pounds of fat to be supplied by the cream. C-f-D=E, pounds of cream required. D-^E^Percentage of fat necessary in E, (4). To calculate the pounds of whole milk, cream, or butter to use. Subtract from the percentage of fat in E, the percentage of fat in the whole milk, and divide the remainder by the difference between the percentage of fat in the butter and the percentage of fat in the whole milk. Multiply the answer by E. Call the result F, or the pounds of butter required. E — F=:the pounds of whole milk required. Solution Problem 37 Based Upon Formula 32 : (1). To calculate the pounds of sweetened condensed skim- milk necessary to furnish the sugar required. QXA (2). To calculate the pounds of skim-milk serum required. (QXS)-(CXD) H_ ^ (3). To calculate the pounds of cream required. K=(QXT)— (CXU+H (4). To calculate the percentage of fat required in the cream. , (QXT)-(CXU) ^= K (5). To calculate the pounds of whole milk and butter to use. ^ (N— M) ^"-^(L=MjX^ PrrzK— 352 Ice Cream Mixes Problem 37, Example 38. Products Pounds Per Cent Fat M.S.N.F. Sugar T. S. Fat M.S.N.F. Sugar T. S. Whole milk 3.50 8.60 12.00 Butter 83.00 1.50 84.50 Sweetened condensed 1.00 28.00 41.00 70.00 88.00 Water Pounds and composition of mix desired 10,000 800.00 1250.0 1300.0 3400.00 8.00 12.50 13.00 34.00 Solution of Problem 37, Example 38, Based Upon Rule 32. (1). To calculate the pounds of sweetened condensed skim- milk required. 10000X-13=1300, pounds of sugar required. 1300-^-.41=3171, pounds of sweetened condensed skim- milk required to furnish the sugar. (2). To calculate the pounds of skim-milk serum required. lOOOOX. 125=1250, pounds of M. S. N. F. required. 3171 X. 28=887.9, pounds of M. S. N. F. in the sweetened condensed skim-milk. 1250—887.9=362.10, pounds of M. S. N. F. to be supplied by the whole milk and the butter. 362.10-^.089=^4069, pounds of skim-milk serum required. (3) . To calculate the pounds of cream required. lOOOOX .08=800, pounds of fat required. 317lX.01=31.7, pounds of fat in the sweetened condensed skim-milk. 800 — 31.7=768.3, pounds of fat to be supplied from whole milk and butter. 4069+768.3=4837.3, pounds of cream required. 768.3h-4837.3=15.88, per cent fat required in the cream. (4). To calculate the pounds of whole milk and butter to use. (.1588— .0350) TT^TTT^ — ^orox X4837=753.5, pounds of butter required. (.8300 — .0350) 4837.3—753.5=4083.8, pounds of whole milk required. Calculations 353 Solution Problem 37, Example 38, Based Upon Formula 32 : (1). To calculate the pounds of sweetened condensed milk necessary to furnish the sugar required. 10000X.13 C: .41 =3171 (2). To calculate the pounds of M. S. N. F. required. (10000X.125)— (3171X.28) H= -^^ =4069 (3). To calculate the pounds of cream required. K=(10000X.08)—(3171X-01) +4069^:4837.3 (4). To calculate the percentage of fat required in the cream. (10000X.08)— (3171X.01) L=r =15.88 4837.3 (5). To calculate the pounds of whole milk and butter to use. (.1588— .0350) P=4837.3— 753.5=4083.8 Proof Problem 37, Example 38. Products Pounds Per Cent Fat M.S.N.F. Sugar T. S. Fat M.S.N.F. Sugar T. S. Whole milk 4083.8 142.9 351.1 494.0 3.50 8.60 12.10 Butter 753.5 625,4 11.3 636.7 83.00 1.50 84.50 Sweetened condensed skim-milk 3171 31.7 887.8 1300.0 2219.6 1.00 28.00 41.00 70.00 Gelatin 50.0 44.0 88.00 Water 1942.7 Pounds and composition of mix ob- tained 10000 800.0 1250.2 3394.3 8.00 12.50 13.00 33.94 In the above proof the percentage of T. S. is slightly lower than desired, due to water contained in gelatin, but close enough under usual conditions of manufacture. 354 Ice Cream Mixks Recipe For Using Sweetened Condensed Skim-milk. Upon the basis of the above solution the following recipe can be used, the same being based upon 100 pounds of mix. 48.4 pounds of cream testing 16.00 per cent fat. 31.7 pounds of sweetened condensed skim-milk. .5 pounds of gelatin. 19.4 pounds of water. 100.0 pounds of total mix, testing 8.00 per cent fat; 12.50 per cent M. S. N. F. ; 13.00 per cent sugar; .50 per cent gelatin ; and 34.00 per cent T. S. Whole milk, cream or butter of any composition can be sub- stituted for the cream testing 16.00 per cent of fat, by using the foregoing methods of calculation. Batches containing any desired number of gallons can be compounded upon the basis of the above recipe by multiplying the number of gallons desired by the pounds per gallon, and in turn the multiples of 100 pounds desired by the pounds given in the above recipe. HOW TO CALCULATE FROM TABLES THE AMOUNT OF SWEETENED CONDENSED SKIM-MILK TO USE. For the benefit of the ice cream maker mixing different sized batches, a great deal of calculation is eliminated and mistakes avoided by making out tables for his use, showing the exact number of pounds of each material necessary in all ordinary sizes of batches. The following tables may prove useful. They are in use in a number of factories, and give uniformly satis- factory results. The variations in fat tests of the different products cause some variation in the tests of finished products, but these may be easily adjusted by standardizing the finished mix. In Table 62 and 63 the gallons of ice cream mix desired are noted at the top, materials to be used at the side, and the pounds of each material necessary directly under the number of gallons. These tables and those given in Table 64 are calculated to produce an ice cream mix testing 8.00 per cent fat, 12.50 per cent M. S. N. F., .50 per cent gelatin, 13.00 per cent sugar and Recipes 355 -{4.00 per cent T. S. All products named have the same composi- tion as given under Problem 37, Example 38. TABLE 62. Table for making various gallons of ice cieam mix using sweetened condensed skim-milk and other products. Composition as named above. Products Total ni imber gallons of ice cream mix desired 150 200 250 300 350 400 450 500 Whole milk lbs. 544 lbs. 726 lbs. 907 lbs. 1090 lbs. 1270 lbs. 1450 lbs. 1625 lbs. 1815 Butter 11.3 137 171 205 240 274 308 342 Sweetened condensed skim-milk 428 560 713 856 1000 1140 1283 1426 Gelatin 6.7 9 11.2 13.5 15.7 18 20.2 22 5 Water 265 353 441 530 618 706 794 895 In some cases whole milk is not always available in sufficient quantity. This is especially true in the south. In this case, skim-milk powder maj^ be used to make up the deficit, and the following formulas are used where skim-milk powder is employed. In Tables 63 and 64 just following, different proportions of skim-milk poAvder are used in each, thus making provision for varying amounts of whole milk that may be available. TABLE 63. Recipes for making various gallonages of ice cream mix, using sweetened condensed skim-milk and other products. Composition as named above. Products Total number of gallon s ice cream mix desired Lbs. 150 Lbs. 200 Lbs. 250 Lbs. 300 Lbs. 350 Lbs. 400 Lbs. 450 Lbs. 500 Whole milk 384 513 640 768 896 1025 1153 1280 Butter 107 142 178 214 249 285 320 356 Sweetened conden.sed skim-milk 428 560 713 856 1000 1140 1283 1426 Gelatin 6.7 9 11.2 13.5 15.7 18 20.2 22.5 Water 408 544 680 816 952 1090 1223 1360 Skim-milk powder 15 20 25 30 35 40 45 50 In case cream is to be made from other materials than butter and 3.50 per cent milk, figure 36.5 pounds of 20.7 per cent cream per 100 pounds of mix wanted. 356 Icp; Cre;am Mixes TABLE 64. Formulas for making various gallonages of ice cream mix using sweetened condensed skim-milk and other products. Composition as named above. Products Total number gallons ice cream mix desired 150 200 250 300 350 400 450 500 Lbs. Lbs. Lbs. Lbs. Lbs. Lbs. Lbs. Lbs. Whole milk 220 294 367 440 514 587 660 734 Butter 112 150 187 224 262 299 337 374 Sweetened condensed skim-milk 428 560 713 856 1000 1140 1283 1426 Gelatin 6.7 9 11.2 13.5 15.7 18 20.2 22.5 Skim-milk powder 30 40 50 60 70 80 90 100 Water 550 733 917 1100 1284 1466 1650 1832 When cream is to be made from other material than butter and 3.5 per cent milk, figure 24.7 pounds of 30.5 per cent cream per 100 pounds of mix wanted. All of the above mixes have given very satisfactory results, and if properly made and homo- genized, any of them will produce 100 per cent overrun, and make a good, smooth and well flavored product. HOW TO STANDARDIZE ICE CREAM MIX BY MEANS OF TABLES BASED UPON USING BUTTER, WATER AND SKIM-MILK POWDER. To J. A. Cross belongs the credit for having developed a simple table method based upon using butter, water and skim- milk powder to effect standardization of ice cream mix. This method can be applied only when these products, and also a' homogenizer, or a viscolizer are available. Similar tables could be made covering other dairy products provided these would be of uniform composition. Butter and skim-milk powder of good quality are nearly constant in composition, readily available and can be conveniently carried in stock. For these reasons they have been selected as the most conveneint standardizing materials. In all of the tables the composition assumed is as follows : Butter 83.00 per cent fat and 1.5 per cent S. N. F. ; skim-milk powder 2.00 per cent fat, and 95.00 per cent S. N. F. Any small variations from these tests will not materially affect the accuracy of the tables. Table References 357 Composition of Mix for Which Tables are Given. — Tables of the above nature can be prepared for any composition of mix. Inasmuch as such a wide range of composition is possible it would be obviously impossible to give within the compass of this book tables to cover all possible compositions. The compositions given are those that have been found under actual use to yield the most satisfactory products, and cover a sufficiently wide range to suit all classes of trade. These are given in Table 65. TABLE 65. Composition of ice cream mix for which standardizing tables are given. No. Table No. Pages Where Found Per Cent of Mix. Fat M. S. N. F. Sugar Gelatin T. S. 1 67 367-372 8.00 11.50 13.00 .50 33.00 2 68 373-378 8.00 12.50- 13.00 .50 34.00 4 69 379-384 9.00 11.50 13.00 .50 34.00 5 70 385-390 10.00 10.50 14,00 .50 35.00 6 71 391-396 12.00 8.50 14.00 .50 35.00 7 72 397-402 12,00 9.50 14,00 .50 36.00 8 73 403-408 16.00 7.50 14,00 .50 38.00 9 74 409-414 18.00 7.50 14.00 .50 40,00 Description of the Tables. — The tables given which are each in turn calculated upon the basis of the compositions given in Table 65 have a range in fat and S. N. F. as given in Table 66. The fat tests will be found upon the top and bottom lines of the tables. The S. N. F. tests upon the vertical line both to the right and to the left of the tables. At the intersection of the fat and S. N. F. columns corresponding to the tests of mix to be standardized, will be found the pounds of powder, water and butter necessary to standardize 1000 pounds of mix of that test. There are three spaces in each square and the figures indicating the pounds of butter, water and powder are in the following order ;— - 358 Ice Cream Mixes Top figure — Butter (Assumed to test 83.00 per cent fat and 1.50 per cent S. N. F.). Center figure — Water. Bottom figure — Skim-milk powder (Assumed to test 2.00 per cent fat and 95.00 per cent S. N. F.) The absence of figures in any space indicates that none of the omitted product is required. TABLE 66, Range of fat and S. N. F. in tables covering mixes of eight different compositions. No. Table No. Pages Where Found Per Cent Range of Fat Range of S. N. F. of iMix. Fat S. N. F. T. S. From To From To 1 67 367-372 8.00 25.00 33.00 6.00 10,00 22,00 28,00 2 68 373-378 8.00 26.00 34.00 6.00 10.00 22,76 29.25 4 69 379-384 9.00 25.00 34.00 7.00 11,00 22,56 27,45 5 70 385-390 10.00 25.00 35.00 8.00 12.00 22,80 27,20 6 71 391-396 12.00 23.00 35.00 10,00 14.00 21.50 24,50 n 72 397-402 12.00 24.00 36.00 10.00 14.00 22.33 25.66 8 73 403-408 16,00 20.00 38.00 14.00 18.00 21.00 23.00 9 74 409-414 18.00 20.00 38.00 16,00 20,00 21,11 22.89 It is assumed that a definite percentage of sugar is always present in the mix that is to be standardized. In order to keep this percentage the same after standardizing, a definite percentage of sugar must be added to the batch along with the standardizing materials. The pounds of sugar to add is ascertained by the following formula : — C^ B^ 'a^— B^ where Dkscription of Tables 35Q A^=100.00, or total percentages in mix B^^Pereentage sugar desired, C^=:The percentage of sugar to be added to the standard- izing materials. Solving the above formulas in the case of mixes containing 13.00 and 14.00 per cent of sugar respectively we have. 13.00 ^ ~ TftfTnn — iTon""'^^'^"^' °^ ^^^® percentage of sugar to be added to standardizing materials when mix with 13.00 per cent of sugar is desired. 14.00 ^^~Tnn — II on =^^-28, or the percentage of sugar to be added to standardizing materials when mix with 14.00 per cent of sugar is desired. To obtain a mix after standardizing that contains the desired percentage of sugar, the total pounds of butter, water and skim- milk powder (or any one or more of these) must be multiplied by the factor C\ and the product, which will be the pounds of sugar required, must be added. Example: — Added in standardizing*: — 10.00 pounds butter. 75.00 pounds water. 15.00 pounds skim-milk powder. 100.00 pounds total. The per cent of sugar desired is 14.0. lOO.OOX-1628 per cent=16.28, pounds sugar desired. 16.28-f-(100f 16.28) =14.00, per cent sugar desired after standardization. These tables are all based upon adding, when compounding the mix, the exact percentage of sugar called for in each of the compositions. How the Tables are Derived. — The successive steps involved in compiling the tables are the same regardless of the composition of 360 Tc^ Cream Mixes mix desired. The various steps together with the principles of calculations involved are as follows : — (1). Determine the exact composition of mix desired. Example : — 8.00 per cent fat. 13.00 per cent sugar \ These three constituents are 11.50 per cent M. S. N. P. i added together and called .50 per cent gelatin ' T. S. N. F. (2). Fill in percentages of fat progressively by .10 per cent from the lowest to the highest range desired. These should be placed in the horizontal spaces both at the top and at the bottom of the table. Calculate by ratio the percentages T. S. N. F. corresponding to the above two percentages of fat. Example : — 8 : 12=6 : X, X=9.00, the per cent M. S. N. F. and gelatin in proportion with 6.00 per cent fat. 9,00+13,00=22,00, the minimum per cent of T. S, N. F. Locate upon Table 67 at A and 8 : 12=10 : X, X=15,00, the per cent M, S. N, F, and gelatin in proportion with 10.00 per cent fat. 15.00+13.00=28.00, the maximum per cent of T. S. N. F. Locate upon Table 67 at B Interpolate the T. S. N. F. in the vertical column from A to B, Each of the eight compositions of mix were compiled upon one large table. These in turn were divided into six sub-tables, each sub-table requiring one page. The letters referred to here- with appear only upon Table 67. (3). Determination of the composition of the products that are to be used in standardizing. Example : — Butter 83.00 per cent fat ; and 1.50 per cent S, N. F. Skim-milk powder 2.00 per cent fat, and 95.00 per cent S. N. F. Sugar 100.00 per cent T, S, (4). Calculate the percentage composition required upon each constituent used in standardizing in order that the resulting mixture after adding the sugar will be properly standardized. Examples 361 Example : — 13.00 100—13 12.00 sToo' .00 87.00' nr: 14.94, the per cent of sugar to add to the other standardizing materials in standardizing to produce a mix containing 13.00 per cent of sugar. :13.79, the per cent of M. S. N. F. (including the gelatin) required in the standardizing mix- ture before adding the sugar. :9.20, the per cent of fat required in the standard- izing mixture before adding the sugar. (5). Calculate the available fat in theoretical mixture No. 1, and the available S. N. F. in theoretical mixture No. 2 using the methods of calculation given in problem 33 of this chapter. Example: — Theoretical mixture No. 1. Butter 1.50 81.21— Butter units 13.79 Skim-milk powder 95.00 12.19 — Skim-milk powder units. 12.29+81.21rr:93.50, the sum of above units. 81.21-^.9350=86.86, parts butter. 12.29^.9350=13.14, parts skim-milk powder. 86.86 parts butter=72.09 parts fat and 1.30 parts M. S. N. F. 13.14 parts skim-milk powder=.26 parts fat and 12,49 parts M. S. N. F. 100.00 parts mixture No. 1=72.35 parts fat and 13.79 parts M. S. N. F. 72.35—9.20=63.15, the per cent of fat in mixture No. 1 available for standardizing. Example theoretical mixture No. 2. Butter 83.00 7.20 Butter units. 9.20 Skim-milk powder 2.00 73.80 skim-milk powder units. 362 Ice Cream Mixes 73.80+7.20=81.00, sum of units. 7.20-:-.81=8.90, parts butter. 73.80-^-.81r=91.10, parts skim-milk powder. 8.90 parts butterr:r7.38 parts fat and .13 parts M. S. N. F, 91.10 parts skim-milk powder=1.82 parts fat and 86.55 parts M. S. N. F. 100.00 parts mixture No. 2=9.20 parts fat and 86.68 parts M. S. N. F. 86.68— 13.79=72.89, per cent S. N. F. in mixture No. 2 available for standardizing. (6). Block off the square CDEF which includes that part of the table when the range is from the minimum under standard to standard in fat and likewise in T, S. N. F. Example: 6.00 to 8.00 per cent in fat and 22.80 to 25.00 in T. S. N. F. At the intersection C, both the fat and the T. S. N. F. are standard. Calculate the pounds of the two mixtures to use. Example : (.08— .06) X 1000 ^oTc =31.7 or pounds mixture No. 1 required. .8686X31.7 = 27.5. pounds of butter required. .1314X31.7:=4.2, pounds skim-milk powder required. Insert these values at E in table. (25.00— 22.00 )X 1000 :=41.2 or pounds mixture No. 2 re- quired. .0890X41.2=3.7, pounds butter required. .9110X41.2=37.5, pounds skim-milk powder required. Insert these values at D in the table. To obtain value of F, add together E and D. Interpolate, either vertically or horizontally in the above square. (7.) Calculate the pounds of water required at the point G in the table. Example ; (.10— .08) X 1000 72.89 .08 =250 250— (250X.1300)=218 CALCiTi^ATiNr, Tablks 363 (8). Calculate the pounds of butter and water to use at the point H in the table. Example: — 8 : 12— X : 1.50. X=:1,00, the per cent of fat required to equalize the S. N. F. in the butter. 88.00—1.00=82.00, the per cent of fat in the butter avail- able for standardizing. (.1000— .0600) X 1000 .82 48.8X.015 =48.8, the pounds of butter to use at H. ^(218— 48.8) =175, the pounds of water to use at H. .1379 (9). Calculate the pounds of water and powder to use at the point I in the table. Example : — 8 : 12=2 : X. X=3.00, the per cent of S. N. F. required to equalize the fat in the skim-milk powder. 95.00—3.00=92.00, the per cent of S. N. F. available for standardizing. (.28— .22) X 1000 _ = 65.2, the pounds of skim-milk powder to use .92 at point I. (65.2X.02) 218-| TT^ 65.2=166, the pounds of water to use at I. (10). Calculate the pounds of water and skim-milk powder to use at Point J in the table. Example : — 8 : 12=8.3 : X. X=12.45, the per cent of S. N. F. re- quired to equalize the percentage of fat at J, (.1245— .0920) X 1000 .92 powder to use at J. 1000X.003 :37.5, the pounds of skim-milk 33, pounds of water to standardize 8.3 per .092 cent fat. (37.5X.02) '^^H :rT7^ 37.5=2, pounds of water to use at J. ,11do 364 Ice; Cream Mixes (11). Calculate the pounds of water and butter to use at point K in the table. Example : — 8 : 12=X : 11.33. X=8.3, the per cent of fat required to equalize the S. N. F. at K. (.083— .06) X 10000 57c —27.1, the pounds of butter to use at K (27.1X.015) (11.33X.11) 27.1 1 -— ^^ =14.0, the pounds of water to use at K. (12). Interpolate from I to G. Interpolate from E to K and K to H. Interpolate from D to J and J to I. Interpolate from H to G and G to I and complete the interpolation of entire table. Proof of the Accuracy of Tables. The tables have been all proved at the points corresponding to the above letters. Tables of any given composition derived as above described, and in which the interpolations have been properl}^ made should prove out at all points, and be correct for any combination of fat and T. S. How to apply the standardization tables in practice. 1. About a half hour before a batch is to be homogenized, turn on the electric current upon the Mojonnier Tester, adjust the fat and solids ovens to the current temperatures, heat, cool and weigh a fat and a T. S. dish, and have everything in readi- ness for a rapid test. 2. Before starting to homogenize the batch, see that all milk powder, butter, sugar, and gelatin are thoroughly dissolved, and that everything that is to be incorporated into the batch is in and mixed thoroughly. The accuracy of the entire system de- pends upon the accuracy of the first sample, and it must be a representative sample of the entire batch 3. A few minutes after the homogenizer is started, obtain a sample from the cooling coils, and analyze for fat and T. S. If everything is in readiness, and the most efficient routine fol- lowed, this test may be completed in 30 minutes or less. (Record time 22 minutes.) SuccRssivR Steps 365 4. Subtract the percentage of fat from the percentage of T. S. The result will be the percentage of T. S. N. F. 5. Locate the most nearly corresponding fat and S. N. F. tests in the table based upon the composition desired. At the intersection will be found the pounds of butter, water or sugar necessary to add to 1000 pounds of mix of that test. Top space is for butter, center space for water, and lower space for skim- milk powder. 6. Multiply the amounts indicated by the number of thousands of pounds of mix to be standardized. Example : If a batch of 2345 pounds is to be standardized, multiply in turn the amounts necessary for 1000 pounds by 2.345. The results will be the pounds of butter, water or skim-milk powder respectively necessary for the entire batch. 7. Add together the total number of pounds of butter, water or sugar and multiply by the percentage of sugar required to produce a mix containing the desired percentage of sugar. Ex- ample : Mix desired to contain 13.00 per cent of sugar. There- fore add here sugar to the extent of 14.94 per cent of the total pounds of other products required for standardizing. The above tests and calculations are made while the batch is being homogenized, and can usually be completed before the entire batch has been run through. The standardizing materials can then be added to the last part of the batch, which has not yet been homogenized. When all has been run through and mixed in the holding tank, the fat and T. S. test should be standard. If skim-milk powder is necessary, it is usually advis- able to stop the homogenizer until it is thoroughly dissolved. Butter, sugar and water in small amounts can usually be mixed without stopping the machine. It is sometimes possible to mix the powder and the sugar with the water which is to be added if it is sufficient in amount, and it is a good practice to keep out about 10 gallons of the water until the batch has run through and then dump this in to wash out the mix remaining in the pipes. 8. Obtain a sample of the standardized batch and analyze for fat and T. S. as a check upon the accuracy of the work. It should be accurate, within .1 of 1.00 per cent upon the fat, and within .20 of 1.00 per cent upon the T. S., of the standard desired. 366 Iciv Crkam Mixys These margins are liberal, and in practice as many as 50 consecu- tive batches have been run out with variation within .07 per cent upon the fat, and within .2 per cent upon the T. S. 9. It is always simpler to standardize with butter and water only. These are easier to mix and to dissolve with the batch. By compounding the mix with an excess of M. S. N. F., the use of skim-milk powder can be reduced to a minimum, or entirely avoided. EXAMPLE AND PROOF OF ACCURACY OF STANDARDIZING TABLES. Example 39, taken from Table 67 showing quantity before standardizing materials added in standardizing, and proof. Pounds Per Cent Products Fat M.S.N. F. including Gelatin Sugar T. S. Fat M.S.N.P. Sugar T. S. Mix before standardzing 1000.0 73.0 111.0 130.0 314.0 7.30 11.10 13.00 31.40 Butter 10.7 8.9 .1 9.0 83.00 1.50 84 50 Water Skim-milk powder 12.7 .3 12.1 12.4 2.00 95.00 97.00 Sugar 3.5 3.5 3.5 100.00 100.00 Total mix after stand- ardizing 1026.9 82.2 123.2 133.5 338.9 8.00 12.00 13.00 33.00 Example 40, taken from Table 67 standardizing ; and materials added in showing quantity before standardizing, and proof. Pounds Per Cent Products Fat M.S.N.F. including Gelatin Sugar T. S. Fat M.S.N.F. Sugar T. S. Mi.x before standardizing 1000.0 91.0 144.0 130.0 365.0 9.10 14.40 13.00 36.50 Butter 6.1 5.1 .1 5.2 83.00 1.50 84 50 Water 170.0 Skim-milk powder 2.00 95.00 97.00 Sugar 28.3 26.3 26.3 100.00 100.00 Total mix after .stand- ardizing 1202.4 96.1 144.1 156.3 396.5 8.00 12.00 13.00 33.00 Compositions of Mixes 367 f S.00'5- Fat Standardizing | 11.507^ M. S N table for ice 1 13.007^ Sugar 'ream mix | .-,o% Gelatin No. I testing: 33.00% T. S. TABLE 67. Basis 1000 rounds of mi.\-. Top and bottom lines : Fat tests. Side columns: S. N. F. tests. In each square: Top figure: Pounds butter Center figure: Pounds water Bottom figure: Pounds skim-milk powder. (Blanks indicate none of kind required.) 368 Ice Cream Mixes TABLE 67 (Continued), standardizing table for ice cream mix No. I testing: 8.00% Fat 11.50% M. S. N. F. 13.00% Sugar .50% Gelatin 33.00% T. S. Basis 1000 pounds of ml.x. Top and bottom Unes: Fat tests. Side columns : S. N. F. tests. In each square : Top figure: Pounds butter. Center figure : Pounds water. Bottom figure: Pounds sklm-milk powder. (Blanks indicate none of kind required.) 6 6.1 6 2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 7 7.1 7.2 7.3 25.00 27.5 E 4.2 26.2 4.0 24.8 3.8 23.4 3.6 22.0 3.4 20.6 3.2 19.2 2.9 17.8 2.7 16.5 2.5 15.1 2.3 13.7 2.1 12.4 1.9 11.0 1.7 9.6 1.5 25.00 25.15 27.3 2.2 26.0 2.0 24.6 1.8 23.2 1.6 21.8 1.4 20.4 1.2 19.0 1.0 17.6 .8 16.3 .6 14.9 .4 13.5 .2 12.2 1 10.9 2 9.7 3 25.15 25.30 27.1 K .3 25.8 .1 24.4 1 23.2 3 22.0 4 20.7 5 19.5 6 18.3 7 17.1 8 15.9 9 14.6 10 13.4 11 12.2 12 10.9 13 25.30 25.45 28.1 8 26.8 9 25. 6 10 24.4 11 23.2 12 22.0 14 20. 7 16 19.5 17 18.3 18 17.1 19 15.9 20 14.6 21 13.4 22 12.2 23 25.45 25.60 29.3 18 28.1 19 26.8 20 25.6 21 24.4 22 23.2 23 22.0 24 20. 7 25 19.5 26 18.3 27 17.1 29 15.9 31 14.6 32 13.4 33 25.60 25.75 30.5 28 29.3 29 28.1 30 26.8 31 25.6 32 24.4 33 23.2 34 22.0 35 20.7 36 19.5 37 18.3 38 17.1 40 15.9 41 14.6 43 2S.7S 25.90 31.7 38 30.5 39 29.3 40 28.1 41 26.8 42 25.6 43 24.4 44 23.2 45 22.0 46 20. 7 47 19.5 49 18.3 50 17.1 51 15.9 52 25.90 26.05 32.9 48 31.7 49 30.5 50 29.3 51 28.1 52 26.8 53 2,5.6 54 24.4 55 23.2 56 22.0 57 20.7 58 19.5 59 18.3 61 17.1 62 26 05 26.20 34.2 58 32.9 59 31.7 60 30.5 61 29.3 62 28.1 63 26.8 64 25.6 65 24.4 66 23.2 67 22.0 68 20.7 69 19.5 70 18.3 71 26.20 26.35 35.4 68 34.2 69 32.9 70 31.7 71 30.5 72 29.3 73 28.1 74 26.8 75 25.6 76 24.4 77 23.2 78 22.0 79 20.7 80 19.5 82 26.35 26 50 36.6 78 35.4 79 34,2 80 32.9 81 31.7 82 30. 5 83 29.3 85 28.1 86 26.8 87 25.6 88 24.4 89 23.2 90 22.0 91 20.7 92 26.50 26.65 37.8 88 36.6 89 35.4 90 34.2 91 32.9 92 31.7 93 30.5 94 29.3 95 28.1 96 26.8 97 25.6 98 24.4 100 23.2 101 22.0 102 26.65 26.80 39.1 98 37.8 99 36.6 100 35.4 101 34.2 102 32.9 103 31.7 104 30.5 105 29.3 106 28.1 107 26.8 108 25.6 109 24.4 111 23.2 112 26.80 26.95 40.3 108 39.1 109 37.8 110 36.6 111 35.4 112 34.2 113 32.9 114 31.7 115 30.5 116 29.3 117 28.1 118 26.8 119 25.6 120 24.4 121 26.95 27.10 41.5 118 40.3 119 39.1 120 37.8 121 36.6 122 35.4 123 34.2 124 32.9 125 31.7 126 30.5 127 29.3 128 28.1 129 26.8 131 25.6 132 27.10 27.25 42.7 128 41.5 129 40.3 130 39.1 131 37.8 132 36.6 133 35.4 134 34.2 135 32.9 136 31.7 137 30.5 138 29.3 139 28.1 140 26.8 142 27.25 27 40 43.9 138 42.7 139 41.5 140 40.3 141 39.1 142 37.8 143 36.6 144 35.4 145 34.2 146 32.9 147 31.7 148 30.5 149 29.3 151 28.1 152 27.40 27.55 45.2 148 43.9 149 42.7 150 41.5 151 40.3 152 39.1 153 37.8 154 36.6 155 35.4 156 34.2 157 32.9 158 31.7 159 30.5 160 29.3 161 27.55 27.70 46.4 158 45.2 159 43.9 160 42.7 161 41.5 162 40.3 163 39.1 164 37.8 165 36.6 166 35.4 167 34.2 168 32.9 169 31.7 170 30.5 171 27.70 27.85 47.6 168 46.4 168 45.2 170 43.9 171 42.7 172 41.5 173 40.3 174 39.1 175 37.8 176 36.6 177 35.4 178 34.2 179 32.9 180 31.7 181 27.85 B 28 00 48.8 17£ H 47. e ire 46.4 17- 45.2 178 43.8 I7f 42.7 180 41. £ 181 40.3 182 39.1 183 37.8 184 36.6 185 35.4 186 34.2 188 32.9 189 28 00 6 6.1 6.; 6 : 6.4 6.£ 6 < > 6.- 6.f 6.£ 7.C 7.1 7.2 7.3 Compositions of Mixes 369 TABLE 67 (Continued). Standardi2ing table for ice cream mix No. I testing: S.007c Fat 11.50% M. S. N. F. 13.007" Sucar .50% Gelatin 33.00% T. S. Basts 1000 pounds of mix. Top and bottom lines : Fat tests. Side columns: S. N. F. tests. In each square: Top figure : Pounds butter. Center fiKure: Pounds water. Bottom figure: Pounds skim -mi lit powder. (Blanks Indicate none of kind reriilired.) 7.4 7.5 7.( 7.- 7.8 7,S 8.C 8.1 8.2 8.: 8.4 8.5 8.6 8.7 22.0 11. S 38. S 10.4 38. S 9.2 38.3 7.S 38.1 6.S 37.9 5.1 37.7 3.7 D 37.5 2.3 37.3 37.1 37. £ 12 39.1 22 40.7 31 42.4 41 44.0 22 22.15 11.7 37.0 10.2 36.7 9.0 36.5 7.6 36.3 6.3 36.1 4.9 35.9 3.S 35.7 2.1 35.5 .7 35.3 4 35. S 13 37.5 23 39.1 32 40.7 42 42.4 22.15 22.30 11. S 35.0 10.0 34.8 8.S 34.6 7.4 34.4 6.1 34.2 4.7 34.0 3.3 33.8 1.9 33.6 .5 33.4 5 34.2 14 35.8 24 37.5 33 39.1 43 40.7 22.30 22.45 11.3 33.2 10.0 32.9 8.6 32.7 7.2 32.5 5.9 32.3 4.6 32.1 3.1 31.9 1.7 31.7 .3 31.5 7 32.6 16 34.2 26 35.8 35 37.5 45 39.1 22.45 22.60 U.l 31.2 9.9 31.0 8.4 30.8 7.0 30. 6 5.7 30.4 4.5 30.2 2.9 30.0 1.5 29.8 .1 29.6 8 30.9 17 32.6 27 34.2 36 35.8 46 37.5 22.60 22.75 11.0 29.3 9.7 29.1 8.2 28.9 6.8 28.7 5.5 28.5 4.2 28..-? 2.8 28.1 1.4 27.9 .0 27.7 9 29.3 18 30.9 28 32.6 37 34.2 47 35.8 22.75 22.90 10.8 27.5 9.5 27.3 8.0 27.1 6.7 26.9 5.3 26.7 4.0 26.5 2.6 26.3 1.2 26.1 1 26.1 10 27.7 18 29.3 29 30.9 38 32.6 48 34.2 22 90 23.05 10.6 25.6 9.3 25.4 7.8 25.2 6.5 25.0 5.1 24.8 3.8 24.6 2.4 24.4 1.0 24.2 3 24.4 11 26.1 19 27.7 30 29.3 39 30.9 49 32.6 23.05 23.20 10.5 23.7 9.1 23.5 7.7 23.3 6.3 23.1 5.0 22.9 3.6 22.7 2.2 22.5 .8 22.3 4 22.8 13 29.4 21 26.1 32 27.7 41 29.3 51 30.9 23.20 23.35 10.3 21.9 8.9 21.6 7.5 21.4 6.1 21.2 4.8 21.0 3.5 20.8 2.1 20. 6 .7 20.4 5 21.2 14 22.8 22 24.4 33 26.1 42 27.7 52 29.3 23.35 23.50 10.1 20.0 8.7 19.8 7.3 19.6 6.0 19.4 4.6 19.2 3.3 19.0 1.9 18.8 .5 18.6 6 19.5 15 21.2 23 22.8 34 24.4 43 26.1 53 27.7 23.50 23,65 9.8 18.2 8.6 17.9 7.1 17.7 5.8 17.5 4.4 17.3 3.1 17.1 1.7 16.9 .3 16.7 7 17.9 16 19.5 24 21.2 35 22.8 44 24.4 54 26.1 23.65 23.80 9.7 16.2 8.4 16.0 7.0 15.8 5.6 15.6 4.3 15.4 2.9 15.2 1.5 15.0 .1 14.8 9 16.3 18 17.9 26 19.5 37 21.2 46 22.8 56 24.4 23.80 23.95 23.95 9.5 14.3 8.2 14.1 6.8 13.9 5.4 13.7 4.1 13.5 2.7 13.3 1.3 13.1 1 13.0 10 14.7 19 16.3 27 17.9 38 19.5 47 21.2 57 22.8 24.10 9.3 12.5 8.0 12.3 6.6 12.1 5.2 11.9 3.9 11.7 2.5 11.5 1.1 11.3 2 11.4 11 13.0 20 14.7 28 16.3 39 17.9 48 19.5 58 21.2 24.10 24.25 9.1 10.6 7.8 10.4 6.5 10.2 5.0 10.0 3.7 9.8 2.4 9.6 1.0 9.4 4 9.8 13 11.4 22 13.0 30 14.7 41 16.3 50 17.9 60 19.5 24.25 24.40 9.0 8.7 7.7 8.5 6.3 8.3 4.8 8.1 3.5 7.9 2.2 7.7 .8 7.5 5 8.2 14 9.8 23 11.4 31 13.0 42 14.7 51 16.3 61 17.9 24.40 24.55 8.8 6.8 7.5 6.6 6.1 6.4 4.7 6.2 3.3 6.0 2.0 5.8 .6 5.6 6 6.5 16 8.2 25 9.8 33 11.4 44 13.0 53 14.7 63 16.3 24.55 24.70 8.6 5.0 7.3 4.8 5.9 4.6 4.5 4.4 3.2 4.2 1.8 4.0 .4 3.8 8 4.9 18 6.5 26 8.2 35 9.8 46 11.4 54 13.0 64 14.7 24.70 24.85 8.4 3.1 7.1 2.9 5.7 2.7 4.3 2.5 3.0 2.3 1.6 2.1 .2 1.9 9 3.2 19 4.9 28 6.5 37 8.2 47 9.8 55 11.4 65 13.0 24.85 7.4 7.5 7.6 7.7 7.8 7.9 8.0 8.1 8.2 8.3 8.4 8.5 8.6 8.7 370 Ice Cream Mixes TABLE 67 (Continued). standardizing table for ice cream mix No. I testing: S.00% Fat 11.50'/r M. S. X. I*". 13.00'7r Sugar .50'7r Gelatin 33.00% T. S. Basis 1000 pounds of mix. Top and fiottom lines: Fat tests. Side rolumns: S. N. F. tests. In each square; Top figure ; Pounds butter. Center figure: Pounds water. Bottom figure: Pounds sliim-millt powder. (Blanks indicate none of kind required.) 7.4 7.5 7.6 7.7 7 8 7.9 8.0 8.1 8.2 8.3 8.4 8.5 8.6 8.7 25.00 8.2 1.3 6.9 1.0 5.5 .8 4.1 .6 2.8 .4 1.4 .2 Std. C 10 1.6 20 3.2 29 4.9 39 6.5 49 8.2 57 9.8 66 11.4 25.00 25.15 8.5 4 7.3 5 6.1 6 4.8 7 3.6 8 2.4 9 1.2 10 11 21 1.6 31 3.2 40 4.9 51 6.5 59 8.2 68 9.8 25.15 25.30 9.7 14 8.5 15 7.3 16 6.1 17 4.8 18 3.6 19 2.4 20 1.2 21 22 32 1.6 42 3.2 52 4.9 61 6.5 61 8.2 25.30 25.45 10.9 24 9.7 25 8.5 26 7.3 27 6.1 28 4.8 29 3.6 30 2.4 31 1.2 32 33 43 1.6 53 3.2 62 4.9 71 6.5 25.45 25.60 12.2 34 10.9 35 9.7 36 8.5 37 7.3 38 6.1 39 4.8 40 3.6 41 2.4 42 1.2 43 44 54 1.6 64 3.2 72 4.9 25.60 25.75 13.4 44 12.2 45 10.9 46 9.7 47 8.5 48 7.3 49 6.1 60 4.8 51 3.6 52 2.4 53 1.2 54 55 65 1.6 74 3.2 25.75 25.90 14.6 53 13.4 54 12.2 55 10.9 57 9.7 58 8.5 59 7.3 60 6.1 61 4.8 62 3.6 63 2.4 64 1.2 65 66 75 1.6 25.90 26.05 15.9 63 14.6 64 13.4 65 12.2 66 10. 9 67 9.7 68 8.5 69 7.3 70 6.1 71 4.8 72 3.6 73 2.4 74 1.2 75 76 26.05 26.20 17.1 72 15.9 73 14.6 74 13.4 75 12.2 76 10.9 77 9.7 78 8.5 80 7.3 81 6.1 82 4.8 83 3.6 84 2.4 85 1.2 86 26.20 26.35 18.3 83 17.1 84 15.9 85 14.6 86 13.4 87 12.2 88 10.9 89 9.7 90 8.5 91 7.3 92 6.1 93 4.8 94 3.6 95 2.4 96 26,35 26.50 19.5 93 18.3 94 17. 1 95 15.9 96 14.6 97 13.4 98 12 2 99 10.9 100 9.7 101 8.5 102 7.3 103 6.1 104 4.8 105 3.6 106 26.50 26.65 20- 7 103 19.5 104 18.3 105 17.1 106 15.9 107 14.6 108 13.4 109 12.2 no 10.9 111 9.7 112 8.5 113 7.3 114 6.1 115 4.8 116 26.65 26.80 22.0 113 20.7 114 19.5 115 18.3 116 17.1 117 15.9 118 14.6 119 13.4 120 12.2 121 10.9 122 9.7 123 8.5 124 7.3 125 6.1 126 26.80 26.95 23.2 122 22.0 123 20.7 124 19.5 125 18.3 126 17.1 127 15.9 128 14.6 129 13.4 130 12.2 131 10.9 132 9.7 134 8.5 135 7.3 136 26 95 27.10 24.4 133 23.2 134 22.0 135 20.7 136 19.5 137 18.3 138 17.1 139 15.9 140 14.6 141 13.4 142 12.2 143 10.9 144 9.7 145 8.5 146 27.10 27.25 25.6 143 24.4 144 23.2 145 22.0 146 20.7 147 19.5 148 18.3 149 17.1 150 15.9 151 14.6 152 13.4 153 12.2 154 10.9 155 9.7 156 27.25 27.40 26.8 153 25.6 154 24.4 155 23.2 156 22.0 157 20.7 158 19.5 159 18.3 160 17.1 161 15.9 162 14.6 163 13.4 164 12.2 165 10.9 166 27.40 27.55 28. 1 162 26.8 163 25.6 164 24.4 165 23.2 166 22.0 167 20.7 168 19.5 169 18.3 170 17.1 171 15.9 172 14.6 173 13.4 174 12.2 175 27.55 27.70 29.3 172 28.1 173 26.8 174 25.6 175 24.4 176 23.2 177 22.0 178 20.7 179 19.5 ISO 18.3 181 17.1 182 15.9 183 14.6 184 13.4 185 27.70 27.85 30.5 182 29 3 183 30.5 191 28.1 184 26.8 185 25.6 186 24.4 187 23.2 188 22.0 189 20.7 190 19.5 191 18.3 192 17.1 193 15.9 194 14.6 195 27.85 28.00 31.7 190 29.3 192 28.1 193 26.8 194 25.6 195 24.4 196 23.2 197 22.0 198 8.2 20.7 200 19.5 201 18.3 202 17.1 203 15.9 204 28.00 7.4 7.5 7.6 7.7 7.8| 7.9 8.0 8.1 8.3 8.4 8.5 8.6 8.7 Compositions of Mixrs 371 standardizing table for ice cream mix No. I testing: TABLE 67 (Continued). S.OO'^r Fat 11.50% M. S. N. F. 13.007? Sugar .50% Gelatin 33.00% T. S. Uasis 1000 pounds of mix. Top iuul Ijottoni lines: Fat tests. Side rolumns: S. N. F. tests. In eacii square: Top figure: Pounds l)utter. Ceiiter figure: Poumls water. Bottom figure: Pounds sltlm-milk powder. {Blanks indicate none of kind re0'/, iM. S. N. F. 1 13.00% Sugar i ..'50% Gelatin 34.00% T. S. -Basis 1000 pounds of mix. Top and Ijoltom lines: Fat tests. Side columns: S. N. F. tests. Tn each sfiuare: Top figure; Pounds butter. Center tlgure : Pounds water. Bottom figure: Poumls skim-milk powder. (Blanks indicate none of kind required. 8 8 8 9 9 9 1 9 2 9 3 9 4 9 5 9 6 9 7 9.8 9 9 10 26.16 77 12.4 87 14.2 96 15.9 106 17.7 115 19.5 125 21.2 134 23.0 144 24.8 153 26.6 163 28.3 172 30.1 182 31.9 191 33.6 26.16 26.32 79 10.6 89 12.4 98 14.2 108 15.9 117 17.7 127 19.5 136 21.2 146 23.0 155 24.8 105 26.6 174 28.3 184 30.1 193 31.9 26.32 26.49 80 8.9 90 10.6 99 12.4 109 14.2 118 15.9 128 17.7 137 19.5 147 21.2 156 23.0 166 24.8 175 26.6 185 28.3 194 30.1 26.49 26 66 82 7.1 92 8.9 101 10.6 111 12.4 120 14.2 130 15.9 139 17.7 149 19.5 158 21.2 168 23.0 177 24.8 187 26.6 196 28.3 26.66 26.82 26.82 83 S.3 93 7.1 102 8.9 112 10.6 121 12.4 131 14.2 140 15.9 150 17.7 159 19.5 169 21.2 178 23.0 188 24.8 197 26.6 26 98 84 3.5 94 5.3 103 7.1 113 8.9 122 10.6 132 12.4 141 14.2 151 15.9 160 17.7 170 19.5 179 21.2 189 23.0 198 24.8 26.98 27.14 86 1.8 96 3.5 105 5.3 115 7.1 124 8.9 134 10.6 143 12.4 153 14.2 162 15.9 172 17.7 181 19.5 191 21.2 200 23.0 27.14 27.30 87 97 1.8 106 3.5 116 5.3 125 7.1 135 8.9 144 10.6 154 12.4 163 14.2 173 15.9 182 17.7 192 19.5 201 21.2 27.30 27.47 1.2 97 98 108 1.8 118 3.5 127 5.3 137 7.1 146 8.9 156 10.6 165 12.4 175 14.2 184 15.9 194 17.7 203 19.5 27.47 27.62 2.4 107 1.2 108 109 119 1.8 128 3.5 138 5.3 147 7.1 157 8.9 166 10.6 176 12.4 185 14.2 195 15.9 204 17.7 27.62 27.78 3.7 116 2.4 118 1.2 119 120 130 1.8 139 3.5 148 5.3 158 7.1 167 8.9 177 10.6 186 12.4 196 14.2 205 15.9 27.78 27.94 27 94 4.9 127 3.7 128 2.4 129 1.2 130 131 141 1.8 150 3.5 160 5.3 169 7.1 179 8.9 188 10.6 198 12.4 207 14.2 28.10 6.1 137 4.9 138 3.7 139 2.4 140 1.2 141 142 152 1.8 161 3.5 170 5.3 180 7.1 189 8.9 199 10.6 208 12.4 28.10 28.27 28.27 7.3 147 6.1 148 4.9 149 3,7 150 2.4 151 1.2 152 153 163 1.8 172 3.5 182 5.3 191 7.1 201 8.9 210 10.6 28.43 8.5 156 7.3 157 6.1 158 4.9 160 3.7 161 2.4 162 1.2 163 164 173 1.8 183 3.5 192 5.3 202 7.1 211 8.9 28.43 28 60 28.76 9.7 166 8.5 167 7.3 168 6.1 169 4.9 170 3.7 171 2.4 172 1.2 173 174 184 1.8 193 3.5 203 5.3 212 7.1 28.60 28.76 11.0 176 9.7 177 8.5 178 7.3 179 6.1 180 4.9 181 3.7 182 2.4 183 1.2 184 185 195 1.8 205 3.5 214 5.3 28 93 29 09 29.25 12.2 184 11.0 186 9.7 188 8.5 189 7.3 190 6.1 191 4.9 192 3.7 193 2.4 194 1.2 195 196 206 1.8 215 3.5 28.93 13.4 195 12.2 196 11.0 197 9.7 198 8.5 200 7.3 201 6.1 202 4.9 203 3.7 204 2.4 20S 1.2 206 207 217 1.8 29 09 14. e 204 13 4 2oe 12 1 207 11. C 20>^ 9.7 20t 8.f 21C 7.C 211 6.1 21i 4.E 2U 3.7 21£ 2.4 21£ 1.1 21" 218 29 25 St 8.S 9 C 9 1 9 5 9.; S.< 9.£ 9.< ; 9 ■ 9 J 9 J 10 Compositions of Mixes 379 r 9.00% Fat Standardizing ) 11.50%, M. S. N. F. table for ice 1 13.00% Sugar cream mix [ .50% Gelatin No. 4 testing: .•(4.00% T. S. TABLE 69. Basis 1000 pounds of mix. Top and bottom Unes: Pat tests. Side coiurans: S. N. F. tests. Ill eaoli sciuare: Top figure: Pounds butter. Center figure: Pounds water. Bottom figure: Pounds sl(im-nii]l< powder. * (Blanlis indicate none of l 8. 5 8. 7 8.1 i 8 } 9. ) 9. 9. 2 9.3 9. t 9. 5 9. 6 9.7 22.56 11. 31. ( ) 10.. ) 30.J 5 9. i 30.f 7. ) 30.^ 7 6..' i 30.i J 4.< 30. ( ) 3.. ) 29.' ) 2. ) 29.' .7 .4 13 21 30 38 r 29.5 30.5 31.8 33.1 34.4 35.8 22.56 22.68 11. f 29. f i 10. C 29.4 8.f 29. i > 7.C 29. C ) 6.] 28. f 4." 28. e r 3.1 28.4 l.E 28.5 28. ( 29.1 ) 14 22 3 30.5 31.8 33. 39 34.4 22.68 22.81 11. e 28. C 10.2 27. S 8.- 27. e 7.4 27.4 5.C 27.2 4.e 27. C 3.1 26. £ 1.7 26.7 26.5 27. S i; 29.] 2a 30.5 35 31. f 40 33.1 22.81 22.93 11.5 26.6 9.9 26.4 8.5 26.2 7.2 26.0 5.7 25.8 4.4 25.6 2.S 25.4 1.5 25.2 .1 25.0 7 26.5 16 27.8 24 29.1 33 30.5 41 31.8 22.93 23 05 11.3 25.1 8.7 24.9 8.4 24.7 7.0 24.5 5.5 24.3 4.2 24.1 2.7 23.9 1.3 23.7 23.8 S 25.2 17 26.5 25 27.8 34 29.1 42 30.5 23.05 23.17 11.1 23.6 9.6 23.4 8.2 23.2 6.8 23.0 5.4 22.8 4.1 22.6 2.6 22.4 1.2 22.2 1 22.5 9 23.8 18 25.2 26 26.5 35 27.8 43 29.1 23 17 23 29 10.9 22.0 9.4 21.9 8.0 21.7 6.6 21.5 5.2 21.3 3.9 21.1 2.4 20.9 1.0 20.7 2 21.2 10 22.5 19 23.8 27 25.2 36 26.5 44 27.8 23.29 23.42 10.7 20.7 9.2 20.5 7.8 20.3 6.4 20.1 5.0 19.9 3.7 19.7 2.2 19.5 .8 19.3 3 19.0 11 21.2 20 22.5 28 23.8 37 25.2 45 26.5 23.42 23.54 10.6 19.2 9.1 19.0 7.7 18.8 6.2 18.6 4.9 18.4 3.5 18.2 2.0 18.0 .6 17.8 4 18.5 12 19.9 21 21.2 29 22.5 38 23.8 46 25.2 23.54 23.66 10.4 17.7 8.9 17.5 7.5 17.3 6.1 17.1 4.7 16.9 3.3 16.7 1.9 16.5 .5 16.3 5 17.2 13 18.5 22 19.9 30 21.2 39 22.5 47 23.8 23.66 23.78 10.2 16.2 8.7 16.0 7.3 15.8 6.0 15.6 4.5 15.4 3.1 15.2 1.7 15.0 .3 14.8 6 15.9 14 17.2 23 18.5 31 19.9 40 21.2 49 22.5 23.78 23 91 10.0 14.7 8.6 14.5 7.1 14.3 5.8 14.1 4.4 13.9 3.8 13.7 1.5 13.5 13.3 7 14.6 15 15.9 24 17.2 32 18.5 41 19.9 50 21.2 23.91 24 03 9.8 13.2 8.4 13.0 7.0 12.8 5.8 12.6 4.2 12.4 2.8 12.2 1.4 12.0 11.8 8 13.3 17 14.6 26 15.9 33 17.2 42 18.5 51 19.9 24 03 24.15 9.6 11.7 8.2 11.5 6.9 11.3 5.4 11.1 4.0 10.9 2.6 10.7 1.2 10.5 1 10.6 9 11.8 18 13.3 27 14.6 34 15.9 43 17.2 52 18.5 24.15 24.27 9.5 10.2 8.1 10.0 6.7 9.8 5.2 9.6 3.9 9.4 2.5 9.3 1.0 9.0 2 9.3 11 10.6 19 11.8 28 13.3 36 14.6 44 15.9 53 17.2 24.27 24.39 9.3 8.7 7.9 8.5 6.5 8.3 5.1 8.1 3.7 7.9 2.3 7.7 .9 7.5 3 7.9 12 9.3 20 10.6 29 11.8 37 13.3 45 14.6 54 15.9 24.39 24.52 9.1 7.2 7.8 7.0 6.3 6.8 4.9 6.6 3.5 6.4 2.1 6.2 .7 6.0 4 6.6 13 7.9 21 9.3 30 10.6 38 U.8 46 13.3 55 14.6 24.52 24.64 8.9 5.7 7.6 5.5 6.2 5.3 4.7 5.1 3.3 4.9 2.0 4.7 .5 4.5 5 5.3 14 6.6 22 7.9 31 8.3 40 10.6 47 11.8 56 13.3 24.64 24.76 8.8 4.2 7.4 4.0 6.0 3.8 4.6 3.6 3.2 3.4 1.8 3.2 .4 3.0 6 4.0 15 5.3 23 6.6 32 7.9 41 8.3 48 10.6 57 11.8 24.76 24.88 8.6 2.7 7.2 2.5 5.8 2.3 4.4 2.1 3.0 1.9 1.6 1.7 1.4 1.5 7 2.7 16 4.0 24 5.3 33 6.6 42 7.9 49 8.3 59 10.6 24.88 25.00 8,4 1.2 7.0 1.0 5.6 .8 4.2 .6 2.8 .4 1.4 .2 8 1.3 17 2.7 25 4.0 34 5.3 43 6.6 5i 7.9 60 8.3 25.00 8.4 8.5 8.6 8.7 8.8 8.9 9.0 9.1 9.2 9.3 9.4 9.5 9.6 9.7 382 Ice Cream Mixes standardizing tabic for ic cream mix No. 4 testii TABLE 69 (Continued). 9.009^ Fat 11.50^ M. S. N. 13.00% Sugar .50% Gelatin 34.00?^ T. S. Basis 1000 pounds of mix. Top and bottom lines: Fat tests. Side columns: S. N. F. tests. In each square: Top figure: rounds butter. Center figure: Pounds water. Bottom figure: Pounds skim-milk powiler. (Blanks indicate none of kind required.) 8.4 8.5 8.6 8.7 8 8 8.9 9 9.1 9.2 9.3 9.4 9.5 9.6 9.7 25.12 8.6 3 7.4 4 6. 1 4.9 6 3.7 7 2.4 8 1.2 9 10 18 1.3 26 2.7 35 4.0 44 5.3 52 6.6 61 7.9 25.12 25.24 9.8 11 8.6 12 7.4 13 6.1 14 4.9 15 3.7 16 2.4 17 1.2 18 19 27 1.3 36 2.7 45 4.0 53 5.3 62 6.6 25.24 25.37 11.0 19 9.8 20 8.6 21 7.4 22 6.1 23 4.9 24 3.7 25 2.4 26 1.2 27 28 37 1.3 46 2,7 54 4.0 63 5.3 25.37 25.49 12.3 28 11.0 29 9.8 30 8.6 31 7.4 32 6.1 33 4.9 34 3.7 35 2.4 36 1.2 37 38 47 1.3 55 2.7 64 4.0 25 49 25.61 13.5 37 12.3 38 11.0 39 9.8 40 8.6 41 7.4 42 6.1 43 4.9 44 3.7 45 2.4 46 1.2 47 48 56 1.3 65 2.7 25.61 25.73 14.7 45 13.5 46 12.3 47 11.0 48 9.8 49 8.6 50 7.4 51 6.1 52 4.9 53 3.7 54 2.4 55 1.2 56 57 66 1.3 25.73 25.86 15.9 54 14.7 55 13.5 56 12.3 57 U.O 58 9.8 59 8.6 60 7.4 61 6.1 62 4.9 63 3.7 64 2.4 65 1.2 66 67 25.86 25.98 17.2 62 15.9 63 14.7 64 13.5 65 12.3 66 11.0 67 9.8 68 8.7 69 7.4 70 6.1 71 4.9 72 3.7 73 2.4 74 1.2 75 25.98 26.10 18.4 70 17.2 71 15.9 72 14.7 73 13.5 74 12.3 75 11.0 76 9.8 77 8.7 78 7.4 79 6.1 80 4.9 81 3.7 82 2.4 83 26.10 26.22 19.6 79 18.4 80 17.2 81 15.9 82 14.7 83 13.5 84 12.3 85 U.O 86 9.8 87 8.7 88 7.4 89 6.1 90 4.9 91 3.7 92 26.22 26.35 20.8 88 19.6 89 18.4 90 17.2 91 15.9 92 14.7 93 13.5 94 12.3 95 U.O 96 9.8 97 8.6 98 7.4 99 6.1 100 4.9 101 26.35 26.47 22.1 96 20.8 97 19.6 98 18.4 99 17.2 100 15.9 101 14.7 102 13.5 103 12.3 104 U.O 105 9.8 106 8.6 107 7.4 108 6.1 109 26 47 26.59 •23.3 105 22.1 106 20.8 107 19.6 108 18.4 109 17.2 110 15.9 111 14,7 112 13.5 113 12.3 114 U.O 115 9.8 116 8.6 117 7.4 118 26 59 26.71 24.5 113 23.3 114 22.1 115 20.8 116 19.6 117 18.4 118 17.2 119 15.9 120 14.7 121 13.5 122 12.3 123 U.O 124 9.8 125 8.6 126 26 71 26.84 25.8 122 24.5 123 23.3 124 22.1 125 20.8 126 19.6 127 18.4 128 17.2 129 15.9 130 14.7 131 13.5 132 12.3 133 U.O 134 9.8 135 26.84 26.96 27.0 130 25.8 131 24.5 132 23 . 3 133 22.1 134 20.8 135 19.6 136 18.4 137 17.2 138 15.9 139 14.7 140 13.5 141 12.3 142 U.O 143 26.96 27.08 27.21 28.2 138 27.0 139 25.8 140 24.5 141 23.3 142 22.1 143 20.8 144 19.6 145 18.4 146 17.2 147 15.9 148 14.7 149 13.5 150 12.3 151 27.08 29.4 147 28.2 148 2:?.o 149 25.8 150 24.5 151 23.3 152 22.1 153 20.8 154 19.6 155 18.4 156 17.2 157 15.9 158 14.7 159 13.5 160 27.21 27.33 30.7 156 29.4 157 28.2 158 27.0 159 25.8 160 24.5 161 23.3 162 22.1 163 20.8 164 19.6 165 18.4 166 17.2 167 15.9 168 14.7 169 27.33 27.45 31.0 168 30 7 169 29.4 170 28.2 171 27.0 172 25.8 173 24.5 174 23 . 3 175 22.1 176 20.8 177 19.6 178 18.4 179 17.2 180 15.9 181 27.45 8.4 8.5 8.6 '8.7 8.8 8.9 9.0 9.1 9.2 9.3 9.4 9.5 9.6 9.7 Compositions op Mixks 383 TABLE 69 (Continued). standardizing table for ice cream mix No. 4 testing r 9.00% Pat J 11.50% M. S. N. F. I 13,00%. Sugar L .50% Gelatin a4.00% T. S. Basi.< 1000 iiouiids of mi.v. Top and bottom lines : Fat tests. Siile eolumns: S. N. F. tests. In each square: ToiJ titiure: Pounds butter. Center figure: Pounds water. Bottom figure: Pounds skim-milk powder. (Blanks indicate none of kind reguired.) 9 8 9 9 10.0 10 1 10.2 10.3 10.4 10.5 10.6 107. 10.8 10 9 110 22.56 47 37.1 55 38.4 63 39.7 72 41.1 80 42.4 89 43.7 97 45.0 106 46.4 114 47.7 122 49.0 131 50.4 139 51.6 148 52.9 22.56 22.68 22.68 48 35.8 56 37.1 64 38.4 72 39.7 81 41.1 90 42.4 98 43.7 107 45.0 115 46.4 123 47.7 132 49.0 140 50.4 149 51.6 22.81 49 3-t.4 57 35.8 65 37.1 72 38.4 82 39.7 91 41.1 99 42.4 108 43.7 116 45.0 124 46.4 133 47.7 141 49.0 150 50.4 22.81 22.93 50 33.1 58 34.4 66 35.8 74 37.1 83 38.4 92 39.7 100 41.1 109 42.4 117 43.7 125 45.0 134 46.4 142 47.7 151 49.0 22.93 23.05 51 31.8 59 33.1 67 34.4 75 35.8 84 37.1 93 38.4 102 39.7 110 41.1 118 42.4 125 43.7 135 45.0 143 46.4 152 47.7 23.05 23.17 52 30.5 60 31.8 68 33.1 76 34.4 85 35.8 94 37.1 102 38.4 111 39.7 119 41.1 127 42.4 136 43.7 144 45.0 153 46.4 23.17 23.29 23.29 53 29.1 61 30.5 69 31.8 78 33.1 86 34.4 95 35.8 103 37.1 112 38.4 120 39.7 128 41.1 137 42.4 145 43.7 154 45.0 23 42 54 27.8 62 29.1 70 30.5 79 31.8 87 33.1 96 34.4 104 35.8 113 37.1 121 38.4 129 39.7 138 41.1 146 42.4 155 43.7 23.42 23.54 55 26.5 63 27.8 71 29.1 80 30.5 88 31.8 97 33.1 105 34.4 115 35.8 122 37.1 130 38.4 139 39.7 147 41.1 156 42.4 23.54 23.66 57 25.2 64 26.5 72 27.8 81 29.1 89 30.5 99 31.8 107 33 . 1 116 34 . 4 124 35.8 131 37.1 140 38.4 144 39.7 157 41.1 23.66 23.78 58 23.8 65 25.2 73 26.5 82 27.8 90 29.1 100 30 . 5 108 31.8 117 33.1 125 34.4 132 35.8 141 37.1 145 38.4 158 39.7 23.78 23.91 59 22.5 66 23.8 74 25.2 84 26.5 92 27.8 101 29.1 109 30.5 118 31.8 128 33.1 134 34.4 143 35.8 151 37.1 160 38.4 23.91 24.03 60 21.2 68 22.5 76 23.8 85 25.2 93 26.5 102 27.8 110 29.1 119 30.5 127 31.8 135 33.1 144 34.4 152 35.8 161 37.1 24.03 24.15 61 19.9 69 21.2 77 22.5 86 23.8 94 25.2 103 26.5 111 27.8 120 29.1 128 30.5 136 31.8 145 33.1 153 34.4 162 35.8 24.15 24.27 62 18.5 70 19.9 78 21.2 87 22.5 95 23.8 104 25.2 112 26.5 121 27.8 129 29.1 137 30.5 146 31.8 154 33.1 163 34.4 24.27 24.39 63 17.2 71 18.5 79 19.9 88 21.2 96 22.5 105 23.8 113 25.2 122 26.5 130 27.8 138 29.1 147 30.5 155 31.8 164 33.1 24.39 24.52 64 15.9 72 17.2 80 18.5 89 19.9 97 21.2 106 22.5 114 23.8 123 25.2 131 26.5 139 27.8 148 29.1 156 30.5 165 31.8 24.52 24.64 65 14.6 73 15.9 81 17.2 90 18.5 98 19.9 107 21.2 115 22.5 124 23.8 132 25.2 140 26.5 149 27.8 157 29.1 166 30.5 24.64 24.76 66 13.3 74 14.6 82 15.9 91 17.2 99 18.5 108 19.9 116 21.2 125 22.5 133 23.8 141 25.2 150 26.6 159 27.8 168 29.1 24.76 24.88 67 11.9 75 13.3 84 14.6 93 15.9 101 17.2 109 18.5 117 19.9 126 21.2 135 22.5 143 23.8 152 25.2 159 26.5 168 27.8 24.88 25.00 68 10.6 76 11.9 85 13.3 94 14.6 102 15.9 110 17.2 lis 18.5 127 19.9 136 21.2 144 22.5 153 23.8 161 25.2 169 26.5 25.00 9.8 9.9 10.0 10.1 10.2 10.3 10.4 10.5 10.6 10.7 10.8 10.9 11.0 384 Ice Cream Mixes TABLE 69 (Continued). standardizing table for ice cream mix No. 4 testing : r 9.00% Pat ■ 11.50% M. S. N. F. 13.00% Sugar .50% Gelatin 34.00% T. S. Dasis 1000 ijouiuis of mix. Top and bottom lines : Fat tests. Side oolurans: S. N. F. tL-sts. In each square: Top figure: Pounds butter. Center figure: Pounds water. Bottom figure: Pounds skim-milk powder. (Blanks Indicate none of kind reauired.) 9 8 9.9 10.0 10.1 10 2 10.3 10.4 10.5 10.6 10.7 10.8 10.9 11.0 25.12 69 9.3 78 10.6 86 11.9 95 13.3 103 14.6 111 15.9 119 17.2 128 18.5 138 19.9 145 21.2 154 22.5 162 23.8 171 25.2 25.12 25.24 70 7.9 79 9.3 87 10.6 96 11.9 104 13.3 113 14.6 120 15.9 129 17.2 138 18.5 146 19.9 155 21.2 163 22.5 172 23.8 25.24 25.37 71 6.6 80 7.9 88 9.3 97 10.6 105 11.9 114 13.3 122 14.6 130 15.9 139 17.2 147 18.5 156 19.9 164 21.2 173 22.5 25.37 25 49 72 5.3 81 6.6 89 7.9 98 9.3 106 10.6 115 11.9 123 13.3 131 14.6 140 15.9 148 17.2 157 18.5 165 19.9 174 21.2 25.49 25.61 73 4.0 82 5.3 90 6.6 99 7.9 107 9.3 116 10.6 124 11.9 132 13.3 141 14.6 149 15.9 158 17.2 166 18.5 175 19.9 25.61 25.73 74 2.7 83 4.0 91 5.3 100 6.6 108 7.9 117 9.3 125 10.6 133 11.9 142 13.3 150 14.6 159 15.9 167 17.2 176 18.5 25.73 25.86 75 1.3 84 2.7 92 4.0 101 5.3 109 6.6 lis 7.9 126 9.3 134 10.6 143 11.9 151 13.3 160 14.6 168 15.9 177 17.2 25.86 25 98 76 85 J1.3 93 2.7 102 4.0 110 5.3 119 6.6 127 7.9 135 9.3 144 10.6 152 11.9 161 13.3 169 14.6 179 15.9 25.98 26 10 1.2 85 86 94 1.3 103 2.7 111 4.0 120 5.3 128 6.6 136 7.9 145 9.3 154 10.6 162 11.9 171 13.3 180 14.6 26 10 26.22 2.4 93 1.2 94 95 104 1.3 112 2.7 121 4.0 129 5.3 137 6.6 146 7.9 155 9.3 163 10.6 172 11.9 181 13.3 26.22 26.35 3.7 102 2.4 103 1.2 104 105 113 1.3 122 2.7 130 4.0 138 5.3 146 6.6 156 7.9 164 9.3 173 10.6 182 11.9 26.35 26.47 4.9 no 3.7 111 2.4 112 1.2 113 114 123 1.3 131 2.7 140 4.0 149 5.3 157 6.6 166 7.9 174 9.3 183 10.6 26.47 26.59 6.1 119 4.9 120 3.7 121 2.4 122 1.2 123 124 132 1.3 141 2.7 150 4.0 158 5.3 167 6.6 175 7.9 184 9.3 26.59 26.71 7.4 127 6.1 128 4.9 129 3.7 130 2.4 131 1.2 132 133 144 1.3 151 2.7 159 4.0 168 5.3 176 6.6 185 7.9 26 71 26.84 8.6 136 7.4 137 6.1 138 4.9 139 3.7 140 2.4 141 1.2 142 143 152 1.3 160 2.7 169 4.0 177 5.3 186 6.6 26.84 26 96 9.S 145 8.6 146 7.4 147 6.1 148 4.9 149 3.7 ISO 2.4 151 1.2 152 153 161 1.3 170 2.7 178 4.0 187 5.3 26.96 27.08 11.0 153 9.8 154 8.6 155 7.4 156 6.1 157 4.9 158 3.7 159 2.4 160 1.2 161 162 171 1.3 179 2.7 188 4.0 27.08 27.21 12.3 162 11.0 163 9.8 164 8.6 165 7.4 166 6.1 167 4.9 168 3.7 169 2.4 170 1.2 171 172 180 1.3 189 2.7 27.21 27.33 13.5 170 12.3 171 11.0 172 9.8 173 8.6 174 7.4 175 6.1 176 4.9 177 3.7 178 2.4 179 1.2 180 181 190 1.3 27.33 27.45 14.7 179 13.5 180 12.3 181 U .0 182 9.8 183 8.6 184 7.4 185 6.1 186 4.9 187 3.7 188 2.4 189 1.2 190 191 27.45 9 8 9.9 10 10 1 10.2 10.3 10 4 10 5 10 6 10.7 10.8 10.9 11.0 Compositions of Mixes 385 standardizing table for ice cream mix No. 5 testing: 10.00% Fat 10.50% M. S. N. F. 14.00% Sugar .50% Gelatin 34.00% T. S. TABLE 70. Basis 1000 pounds of mix. Top and bottom Unes : Fat tests. Side colimins: S. N. F. tests. In each square: Top figure : Pounds butter. Center figure: Pounds water. Bottom figure: Pounds skim -milk powder. (Blanks indicate none of kind required.) 8.0 8.1 8,2 8.3 8,4 8,5 8,6 8,7 8,8 8,9 9 9 1 9,2 9,3 22.80 32.2 31.1 30. S 30.8 29,3 30,7 27.9 30,5 26, S 30,3 25,1 30,1 23,6 29, S 22.2 29,7 20, i 29,6 19,3 29.4 17, E 29, i 16,5 29,0 15.0 28,8 13,6 28.6 22,80 22.91 32.2 29.7 30.6 29.5 29,1 29.3 27,7 29,1 26,3 28,9 24,9 28,7 23,4 28,5 22,0 28,3 20,6 28,1 19,1 28,0 17.7 27,8 16,3 27,6 14,8 27,4 13,4 27,2 22.91 23.02 32.0 28.4 30.4 28.2 28,9 28,0 27,5 27.8 26,2 27,6 24,7 27,4 23,2 27,2 21,8 27,0 20,5 26,8 IS, 9 26.6 17,5 26,5 16,1 26,3 14.6 26,1 13,2 25,9 23,02 23.13 31.8 27.0 30.2 26.8 28,7 26,6 27.3 26,4 26,0 26,2 24,5 26,0 23,0 25,8 21,6 25.6 20,3 25,4 18,7 25,2 17,3 25,1 16,0 24,9 14,4 24,7 13,0 24,5 23,13 23.24 31.6 25.7 30.0 25.5 28,5 25,3 27,1 25,1 25,8 24,9 24,3 24,7 22,8 24,5 21,4 24,3 20,2 24,1 18,5 24,0 17,1 23,8 15,8 23,6 14,2 23.4 12,8 23,2 23,24 23.35 31.5 24.3 29.9 24.1 28,4 23,9 27,0 23,7 25,6 23,5 24,1 23,3 22,7 23,1 21,2 22,9 20,0 22,7 18,3 22,5 17,0 22,4 15.6 22,2 14,1 22,0 12,7 21.8 23.35 23.46 31.3 22.9 29.8 22.7 28,2 22,5 26,8 22,3 25,4 22,1 24,0 21,9 22,5 21,7 21,1 21,5 19,8 21,3 18,1 21,1 16,8 20,9 15,4 20.8 13,9 20,6 12,5 20,4 23 46 23.57 31.1 21.6 29.6 21.4 28,0 21,2 26.6 21,0 25.2 20,8 23,8 20.0 22,3 20,4 20,9 20,2 19,6 20,0 ISO 19,8 16,6 19,6 15,2 19,5 13,7 19,3 12.3 19,1 23,57 23.68 30.9 20.2 29.4 20.0 27,9 19,8 26,4 19,6 25.0 19,4 23,6 19,2 22,2 19,0 20,7 18,8 19,4 18,6 17,8 18,4 16,4 18,3 15.0 18,1 13,5 17,9 12,1 17,7 23 68 23.79 30.8 18.9 29.2 18.7 27.7 18,5 26,3 18,3 24,9 18.1 23,4 17,9 22,0 17.7 20,5 17,5 19,2 17,3 17,6 17,1 16,2 17,0 14,8 16,8 13,3 16,6 11.9 16,4 23 79 23 90 30.6 17.5 29.0 17.3 27,5 17,1 26,1 16,9 24,8 16,7 23,2 16,5 21.8 16,3 20,3 16,1 19,1 16,0 17,4 15,8 16,0 15,6 14,6 15,4 13,1 15,2 11,8 15,0 23,90 24.01 30.4 16.1 28.9 15.9 27,3 15,7 26,0 15,5 24,6 15.3 23,0 15,1 21,7 14,9 20,1 14,7 18,9 14,5 17,2 14,3 15.9 14,2 14,4 14,0 12,9 13,8 11,6 13,6 24 01 24.12 30.2 14.8 28.7 14.6 27.2 14.4 25,8 14,2 24,4 14,0 22,8 13,8 21,5 13,6 20,0 13,4 18,7 13,2 17,0 13,0 15,7 12,9 14,2 12,7 12,8 12,5 11,4 12.3 24,12 24.23 30.0 13.4 28.5 13.2 27,0 13,0 25,6 12,8 24,2 12,6 22,6 12,4 21,3 12,2 19,8 12,0 18,5 11.8 16,8 11,7 15.5 11,5 14,0 11,3 12,6 11,1 11,2 10,9 24 23 24.34 29,7 12.1 28.3 11.9 26,9 11,7 25,4 11,5 24,0 11,3 22,5 11,1 21,1 10,9 19,6 10,7 18,3 10,5 16,6 10,4 15,4 10,2 13,9 10-0 12.4 9,8 11,0 9,6 24,34 24.45 29.5 10.7 28.1 10.5 26,7 10,3 25,2 10,1 23,9 9,9 22,3 9,7 21,0 9,5 19,4 9,3 18,1 9,2 16,4 9,0 15,2 8,8 13,7 8,6 12.2 8,4 10,9 8,2 24 45 24.56 29.3 9.3 27.9 9.1 26.5 8,9 25,0 8,7 23,7 8,5 22,1 8,3 20,8 8,1 19,3 8,0 18,0 7,8 16,3 7.6 15,0 7,4 13,5 7.2 12,0 7,0 10,7 6,8 24 56 24.67 29.1 8.0 27.8 7.8 26,3 7,6 24,8 7,4 23.5 7.2 21,9 7,0 20,6 6,8 19,1 6,6 17,8 6,4 16,1 6.2 14,9 6.1 13,3 5,9 11,9 5,7 10,5 5,5 24,67 24.78 28.9 6.6 27,6 6,4 26.1 6,2 24,6 6,0 23.3 5.8 21,7 5,6 20.4 5,4 19,0 5,2 17,6 5,0 15,9 4,9 14.7 4,7 13,1 4,5 11,8 4,3 10,4 4.1 24.78 24.89 28.8 5.3 27,4 5,1 25.9 4,9 24,5 4,7 23,1 4,5 21,5 4,3 20,2 4,1 18,8 3.9 17,4 3,7 15,7 3,6 14,5 3,4 13,0 3,2 11,6 3,0 10,2 2,8 24 89 25.00 28.6 3.9 27,2 3,7 25,7 3,5 24,3 3,3 22,9 3,1 21,5 2.9 20,0 2,7 18.6 2.5 17,2 2,3 15,7 2,1 14,3 2,0 12,9 1.8 11,4 1.6 10,0 1,4 25.00 8.0 8,1 8,2 8,3 8,4 8 5 8,6 8,7 8 8 8,9 9 9,1 9.2 9,3 386 Ice Cream Mixes TABLE 70 (Continued). standardizing table for ice cream mix No. 5 testing: 10.00% Fat 10.50% M. S. N. 14.007o Sugar .50% Gelatin 34.00% T. S. Basis 1000 pounds of mix. Top and bottom lines : Fat tests. Side columns : S. N. F. tests. In each sauare: Top figure: Pounds butter. Center figure: Pounds water. Bottom figure: Pounds sliim-mllk powder. (Blanlis indicate none of kind reauired.) 8.0 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 9.0 9.1 9.2 9.3 25.11 28.4 2.5 27.0 2.3 25.5 2.1 24.1 1.9 22.7 1.7 21.3 1.5 19.8 1.3 18.4 1.1 17.0 .9 15.5 .7 14.1 .6 12.7 .4 11.2 .2 9.8 .0 25.11 25.22 28.2 1.2 26.8 1.0 25.3 .8 23.9 .7 22.5 .5 21.1 .3 19.6 .1 18.4 1 17.2 2 15.9 3 14.7 4 13.5 6 12.3 7 11.0 8 25.22 25.33 28.2 1 27.0 2 25.7 3 24.5 4 23.3 5 22.1 6 20.8 7 19.6 8 18.4 10 17.2 11 15.9 12 14.7 13 13.5 14 12.3 16 25.33 25.44 29.4 9 28.2 10 27.0 11 25.7 12 24.5 13 23.3 14 22.1 15 20.8 16 19.6 17 18.4 19 17.. 2 20 15.9 21 14.7 22 13.5 23 25.44 25.55 30.6 16 29.4 17 28.2 18 27.0 19 25.7 20 24.5 21 23.3 22 22.1 23 20.8 24 19.6 25 18.4 26 17.2 27 15.9 28 14.7 30 25.55 25. 6G 31.9 24 30.6 25 29.4 26 28.2 27 27.0 28 25.7 29 24.5 31 23.3 32 22.1 33 20.8 34 19.6 35 18.4 36 17.2 37 15.9 38 25.66 25.77 33.1 31 31.9 32 30.6 33 29.4 34 28.2 35 27.0 36 25.7 37 24.5 39 23.3 40 22.1 41 20.8 42 19.6 43 18.4 44 17.2 45 25.77 25.88 34.3 39 33.1 40 31.9 41 30.6 42 29.4 43 28.2 44 27.0 45 25.7 46 24.5 47 23.3 48 22.1 49 20.8 51 19.6 52 18.4 53 25.88 25.99 35.5 46 34.3 47 33.1 48 31.9 49 30.6 50 29.4 52 28.2 53 27.0 54 25.7 55 24.5 56 23.3 57 22.1 58 20.8 59 19.6 60 25.99 26.10 36.8 54 35.5 55 34.3 56 33.1 57 31.9 58 30.6 59 29.4 60 28.2 62 27.0 63 25.7 64 24.5 65 23.3 66 22.1 67 20.8 68 26.10 26 21 38.0 61 36.8 62 35.5 63 34.3 65 33.1 66 31.9 67 30.6 68 29.4 69 28.2 71 27. 72 25.7 73 24.5 74 23.3 75 22.1 76 26 21 26 32 39.2 69 38.0 70 36.8 71 35.5 72 34.3 73 33.1 74 31.9 75 30.6 76 29.4 77 28.2 78 27.0 80 25.7 81 24.5 82 23.3 83 26.32 26 43 40.4 76 39.2 77 38.0 78 36.8 79 35.5 80 34.3 81 33.1 82 31.9 83 30.6 84 29.4 85 28.2 86 27.0 88 25.7 89 24.5 91 26.43 26.54 41.7 84 40.4 85 39.2 86 38.0 87 36.8 88 35.5 89 34.3 90 33.1 91 31.9 92 30.6 93 29.4 94 28.2 95 27.0 97 25.7 98 26.54 26.65 42.9 91 41.7 92 40.4 93 39.2 94 38.0 95 36.8 96 35.5 97 34.3 98 33.1 99 31.9 100 30.6 101 29.4 102 28.2 103 27.0 104 26 65 26.76 44.1 99 42.9 100 41.7 101 40.4 102 39.2 103 38.0 104 36.8 105 35.5 106 34.3 107 33.1 108 31.9 109 30.6 110 29.4 112 28.2 113 26 76 26.87 45.3 106 44 1 107 42.9 108 41.7 109 40.4 110 39.2 111 38.0 113 36.8 114 35.5 115 34.3 116 33.1 117 31.9 lis 30.6 119 29.4 120 26.87 26.98 46.6 114 45.3 115 44.1 116 42.9 117 41.7 118 40.4 119 39.2 120 38.0 122 36.8 124 35.5 125 34.3 126 33.1 127 31.9 128 30.6 129 26.98 27.09 47.8 121 46.6 122 45.3 123 44.1 124 42.9 125 41.7 126 40.4 127 39.2 128 38.0 129 36. S 130 35.5 131 34.3 132 33.1 134 31.9 135 27 09 27.20 49. 129 47.8 130 46.6 131 45.3 132 44.1 133 42.9 134 41.7 135 40.4 136 39.2 138 38.0 139 36. S 140 35.5 141 34.3 142 33.1 143 27.20 8 8 1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 9.0 9 1 9 2 9.3 Compositions of Mixes 38; TABLE 70 (Continued). standardizing table for ice cream mix No. 5 testing: Fat icoc; 10.507o M. S. N. 14.00% Sugar L .50% Gelatin 34.00% T. S. Basis 1000 pounds of mix. Top and bottom Unes: Fat tests. Side columns: S. N. F. tests. In each square: Top tigure: Pounds butter. Center figure : Pounds water. Bottom figure: Pounds sklm-mllk powder. (Blanks indicate none of kind reaulred. ) 9 4 9.5 9.6 9 7 9.8 9 9 10.0 10 1 10.2 10.3 10.4 10.5 10.6 10.7 22.80 12.2 28.4 10.7 28.2 9.3 28.0 7.9 27.8 6.5 27.6 5.0 27.4 3.6 27.2 2.2 27.0 .7 26.8 3 27.2 11 28.4 18 29.6 26 30.7 34 31.9 22.80 22.91 12.0 27.0 10.6 26.8 9.1 26.6 7.7 26.4 6.3 26.2 4.8 26.0 3.4 25.8 2.0 25.6 .5 25.4 4 26.0 12 27.2 19 28.4 27 29.6 35 30.7 22.91 23.02 11.8 25.7 10.4 25.5 8.9 25.3 7.S 25.1 6.1 24.9 4.6 24.7 3.2 24.5 1.8 24.3 .3 24.1 5 24.8 13 26.0 20 27.2 28 28.4 36 29.6 23.02 23.13 11.7 24.3 10.3 24.1 8.8 23.9 7.3 23.7 5.9 23.5 4.5 23.3 3.1 23.1 1.7 22.9 .2 22.7 6 23.7 14 24.8 21 26.0 29 27.2 37 28.4 23 13 23.24 11.5 23.0 10.1 22.8 8.6 22.6 7.2 22.4 5.7 22.2 4.3 22.0 2.9 21.8 1.5 21.6 .0 21.3 22.5 15 23.7 22 24.8 30 26.0 38 27.2 23.24 23.35 11.4 21.6 10.0 21.4 8.5 21.2 7.0 21.0 5.5 20.8 4.1 20.6 2.7 20.4 1.3 20.2 1 20.1 8 21.3 15 22 . 5 23 23.7 31 24.8 39 26.0 23.35 23 46 11.2 20.2 9.8 20.0 8.3 19.8 6.8 19.6 5.3 19.4 3.9 19.2 2.5 19.0 1.1 18.8 2 18.9 9 20.1 16 21.3 24 22.5 32 23.7 40 24.8 23.46 23.57 11.0 18.9 9.6 18.7 8.1 18.5 6.6 18.3 5.1 18.1 3.7 17.9 2.3 17.7 .9 17.5 3 17.7 10 18.9 17 20.1 25 21.3 33 22.5 41 23.7 23.57 23.68 10.9 17.5 9.4 17.3 7.9 17.1 6.4 16.9 5.0 16.7 3.6 16.5 2.2 16.3 .8 16.1 4 16.6 11 17.7 18 18.9 26 20.1 34 21.3 42 22.5 23.68 23.79 10.7 16.2 9.2 16.0 7.7 15.8 6.2 15.6 4.8 15.4 3.4 15.2 2.0 15.0 .6 14.8 5 15.4 12 16.6 19 17.7 27 18.9 35 20.1 43 21.3 23.79 23 90 10.5 14.8 9.0 14.6 7.5 14.4 6.1 14.2 4.6 14.0 3.2 13.8 1.8 13.6 .4 13.4 6 14.2 13 15.4 20 16.6 28 17.7 36 18.9 44 20.1 23 90 24 01 10.4 13.4 8.9 13.2 7.3 13.0 5.9 12.8 4.4 12.6 3.0 12.4 1.6 12.2 .2 12.0 7 13.0 14 14.2 21 15.4 29 16.6 37 17.7 45 18.9 24 01 24 12 10.2 12.1 8.7 11.9 7.1 11.7 5.7 11.5 4.2 11.3 2.8 11.1 1.4 10.9 .0 10.7 8 11.8 15 13.0 22 14.2 30 15.4 38 16.6 46 17.7 24.12 24.23 10.0 10.7 8.5 10.5 6.9 10.3 5.5 10.1 4.1 9.9 2.7 9.7 1.3 9.5 1 9.5 9 10.6 16 11.8 23 13.0 31 14.2 39 15.4 47 16.6 24.23 24.34 9.8 9.4 8.3 9.2 6.7 9.0 5.3 8.8 3.9 8.6 2.5 8.4 1.1 8.2 2 8.3 10 9.5 17 10.6 24 11.8 32 13.0 40 14.2 48 15.4 24.34 24.45 9.6 8.0 8.1 7.8 6.6 7.6 5.2 7.4 3.7 7.2 2.3 7.0 .9 6.8 3 7.1 11 8.3 18 9.5 25 10.6 33 11.8 41 13.0 49 14.2 24.45 24.56 9.4 6.6 8.0 6.4 6.4 6.2 5.0 6.0 3.6 5.8 2.1 5.6 .7 5.4 4 5.9 12 7.1 19 8.3 26 9.5 34 10.6 42 11.8 50 13.0 24.56 24.67 9.2 5.3 7.8 5.1 6.2 4.9 4.9 4.7 3.4 4.5 1.9 4.3 .5 4.1 5 4.7 12 5.9 20 7.1 27 8.3 35 9.5 43 10.6 50 11.8 24.67 24.78 9.0 3.9 7.6 3.7 6.1 3.5 4.7 3.3 3.3 3.1 1.8 2.9 .4 2.7 6 3.5 13 4.7 21 5.9 28 7.1 36 8.3 44 9.5 51 10.6 24.78 24.89 8.8 2.6 7.4 2.4 5.9 2.2 4.5 2.0 3.1 1.8 1.6 1.6 .2 1.4 7 2.4 14 3.5 22 4.7 29 5.9 37 7.1 45 8.3 52 9.5 24.89 25.00 8.6 1.2 7.2 1.0 5.7 .8 4.3 .6 2.9 .4 1.4 .2 8 1.2 15 2.4 23 3 5 30 4.7 38 5.9 46 7.1 53 8.3 25 00 9 4 9.5 9.6 9 7 9.8 9 9 10 10.1 10.2 10 3 10 4 10.5 10 6 10 7 388 Ice Cream Mixes TABLE 70 (Continued). standardizing table for ice cream mix No. 5 testing: in.00'7^ Fat 10.50% M. S. N. F. 14.00% Sugar 1 .50% Gelatin , 34.00% T. S. Basis 1000 pounds of mix. Top and bottom lines: Fat tests. Side columns: S. N. F. tests. In each square: Top figure: Pounds butter. Center figure: Pounds water. Bottom figure: Pounds skim-mllk powder. (Blanks indicate none of kind required.) 9 4 9.5 9.6 9.7 9.8 9.9 10.0 10.1 10.2 10.3 10.4 10.5 10.6 10.7 25.11 8.6 1 7.4 2 6.1 3 4.9 5 3.7 6 2.4 7 1.2 8 9 16 1.2 24 2.4 31 3.5 39 4.7 47 5.9 54 7.1 25.11 25.22 9.8 9 8.6 10 7.4 11 6.1 12 4.9 13 3.7 14 2.4 15 1.2 16 17 25 1.2 32 2.4 40 3.5 48 4.7 55 5.9 25.22 25.33 11.0 17 9.8 18 8.6 19 7.4 20 6.1 21 4.9 22 3.7 23 2.4 24 1.2 25 26 33 1.2 41 2.4 49 3.5 56 4.7 25.33 25.44 12.3 24 10.0 25 9.8 26 8.6 27 7.4 28 6.1 29 4.9 30 3.7 31 2.4 32 1.2 33 34 42 1.2 50 2.4 57 3.5 25.44 25.55 13.5 31 12.3 32 11.0 33 9.8 34 8.6 35 7.4 37 6.1 38 4.9 39 3.7 40 2.4 41 1.2 42 43 51 1.2 58 2.4 25.55 25 66 14.7 39 13.6 40 12.3 41 11.0 42 9.8 44 8.6 45 7.4 46 6.1 47 4.9 48 3.7 49 3.4 50 1.2 51 52 59 1.2 25.66 25.77 15.9 46 14.7 47 13.5 49 12.3 50 11.0 51 9.8 52 8.6 53 7.4 54 6.1 55 4.9 56 3.7 57 3.4 58 1.2 59 60 25.77 25.88 17.2 54 15.9 55 14.7 56 13.5 57 12.3 58 11.0 60 9.8 61 8.6 62 7.4 63 6.1 64 4.9 65 3.7 66 3.4 67 1.2 68 25.88 25.99 18.4 61 17.2 62 15.9 63 14.7 64 13.5 65 12.3 66 11.0 67 9.8 68 8.6 70 7.4 71 6.1 72 4.9 73 3.7 74 3.4 75 25.99 26 10 19.6 69 18.4 70 17.2 71 15.9 72 14.7 73 13.5 74 12.3 75 11 76 9.8 78 8.6 79 7.4 80 6.1 81 4.9 82 3.7 83 26.10 26.21 20.8 77 19.6 78 18.4 80 17.2 81 15.9 82 14.7 83 13.5 84 12.3 85 11.0 86 9.8 87 8.6 88 7.4 89 6.1 90 4.9 91 26.21 26.32 22.1 84 20.8 85 19.6 86 18.4 87 17.2 88 15.9 89 14.7 90 13.5 91 12.3 93 11.0 94 9.8 95 8.6 96 7.4 97 6.1 98 26.32 26.43 23.3 92 22.1 93 20.8 94 19.6 95 18.4 96 17.2 97 15.9 98 14.7 100 13.5 101 12.3 102 11.0 103 9.8 104 8.6 105 7.4 106 26.43 26.54 24.5 99 23.3 100 22.1 101 20.8 102 19.6 103 18.4 104 17.2 106 15.9 107 14.7 108 13.5 109 12.3 110 11.0 111 9.8 112 8.6 113 26.54 26 65 25.7 106 24.5 107 23.3 108 22.1 109 20.8 110 19.6 112 18.4 113 17.2 114 15.9 116 14.7 117 13.5 118 12.3 119 11.0 120 9.8 121 26.65 26.76 27.0 114 25.7 115 24.5 116 23.3 117 22.1 118 20.8 119 19.6 120 18.4 121 17.2 122 15.9 123 14.7 124 13.5 126 12.3 127 11.0 128 26.76 26 87 28.2 121 27.0 122 25.7 123 24.5 125 23.3 126 22.1 127 20,8 128 19.6 129 18.4 130 17.2 131 15.9 132 14.7 133 13.5 134 12.3 135 26 87 26 98 29.4 130 28.2 131 27.0 132 25.7 133 24.5 134 23.3 136 22.1 137 20.8 138 19.6 139 18.4 140 17.2 141 15.9 142 14.7 143 13.5 144 26.98 27.09 30.6 136 29.4 137 28.2 138 27.0 140 25.7 141 24.6 142 23.3 143 22.1 145 20.8 146 19.6 147 18.4 148 17.2 149 15.9 150 14.7 151 27 09 27.20 31.9 144 30.6 145 29.4 146 28.2 147 27.0 148 25.7 150 24 . 5 151 23.3 152 22.1 153 20.8 154 19.6 155 18.4 156 17.2 157 15.9 158 27 20 9.4 9.5 9 6 9.7 9.8 9 9 10 10 I 10.2 10 3 10 4 10.5 10.6 10.7 Compositions of Mixes 389 TABLE 70 (Continued). 1 10.009-« Fat Basis 1000 pounds of Stanaarai2ing j 10.50% M. S. N. F. mix. table for ice 1 14.00% Sugar Top and bottom lines ; cream mix I .50% Gelatin Fat tests. No. 5 testing : Side oolumns: 34.00% T. S. S. N. F. tests. In each square: Top figure: Pounds butter. Center figure: Pounds water. Bottom figure: Pounds skim-nnlk powder. (Blanks indicate none of kind required.) 10.8 10.9 11 .0 11.1 11.2 11.3 U.4 11.5 11.6 U.7 11.8 11 .9 12.0 22.80 41 33.1 49 34.3 57 35.5 64 36.7 72 37.8 79 39.0 87 40.2 95 41.4 102 42.6 110 43.8 118 44.9 125 46. 1 133 47.3 22 80 22 91 42 31.9 50 33.1 58 34.3 65 35.5 73 36.7 80 37.8 88 39.0 96 40.2 103 41.4 111 42.6 119 43.8 126 44.9 134 46.1 22.91 23 02 43 30.7 51 31.9 59 33.1 66 34.3 74 35.5 81 36.7 89 37.8 97 39.0 104 40.2 112 41.4 120 42.6 127 43.8 135 44.9 23.02 23 13 44 29.6 52 30.7 60 31.9 67 33.1 75 34.3 82 35.5 90 36.7 98 37.8 105 39.0 113 40.2 121 41.4 128 42.6 136 43.8 23.13 23.24 45 28.4 53 29.6 61 30.7 68 31.9 76 33.1 83 34.3 91 35.5 99 36.7 106 37.8 114 39.0 122 40.2 129 41.4 137 42.6 23.24 23.35 46 27.2 54 28.4 62 29.6 69 30.7 77 31.9 84 33.1 92 34.3 100 35.5 107 36.7 115 37.8 123 39.0 130 40.2 138 41.4 23.35 23.46 47 26.0 55 27.2 63 28.4 70 29.6 78 30.7 85 31.9 93 33.1 101 34.3 108 35.5 116 36.7 124 37.8 131 39.0 139 40.2 23.46 23.57 48 24.8 56 26.0 64 27.2 71 28.4 79 29.6 86 30.7 94 31.9 102 33.1 109 34.3 117 35.5 125 36.7 132 37.8 140 39.0 23.57 23.68 49 23.7 57 24.8 65 26.0 72 27.2 80 28.4 87 29.6 95 30.7 103 31.9 110 33.1 118 34.3 126 35 . 5 133 36.7 141 37.8 23.68 23.79 50 22.5 58 23.7 66 24.8 73 26.0 81 27.2 88 28.4 96 29.6 104 30.7 111 31.9 119 33.1 127 34.3 134 35.5 142 36.7 23.79 23 90 51 21.3 59 22.5 67 23.7 74 24.8 82 26.0 89 27.2 97 28.4 105 29.6 112 30.7 120 31.9 128 33.1 135 34.3 143 35.5 23.90 24 01 52 20.1 60 21.3 68 22.5 75 23.7 83 24.8 90 26.0 98 27.2 106 28.4 113 29.6 121 30.7 129 31.9 136 33.1 144 34.3 24.01 24.12 53 18.9 61 20.1 69 21.3 76 22.5 84 23.7 91 24.8 99 26.0 107 27.2 114 28.4 122 29.6 130 30.7 137 31.9 145 33,1 24.12 24.23 54 17.7 62 18.9 70 20.1 77 21.3 85 22.5 92 23.7 100 24.8 108 26.0 115 27.2 123 28.4 131 29.6 138 30.7 146 31.9 24.23 24.34 55 16.6 63 17.7 71 18.9 78 20.1 86 21.3 93 22.5 100 23.7 109 24.8 116 26.0 124 27.2 132 28.4 139 29.6 147 30.7 24.34 24.45 56 15.4 64 16.6 72 17.7 79 18.9 86 20.1 94 21.3 101 22.5 110 23.7 117 24.8 125 26.0 133 27.2 140 28.4 148 29.6 24.45 24 56 57 14.2 65 15.4 72 16.6 80 17.7 87 18.9 95 20.1 102 21.3 111 22.5 118 23.7 126 24.8 134 26.0 141 27.2 149 28.4 24.56 24 67 58 13.0 65 14.2 73 15.4 81 16.6 88 17.7 96 18.9 103 20.1 111 21.3 119 22.5 127 23.7 135 24.8 142 26.0 150 27.2 24.67 24.78 59 11.8 66 13.0 74 14.2 82 15.4 89 16.6 97 17.7 104 18.9 112 20.1 120 21.3 128 22.5 136 23.7 143 24.8 151 26.0 24.78 24.89 60 10.6 67 11.8 75 13.0 83 14.2 90 15.4 98 16.6 105 17.7 113 18.9 121 20.1 129 21.3 137 22.5 144 23.7 152 24.8 24.89 25.00 61 9.5 68 10.6 76 11.8 84 13.0 91 14.2 99 15.4 106 16.6 114 17.7 122 18.9 130 20.1 137 21.3 145 22.5 153 23.7 25.00 10.8 10.9 11.0 11.1 11.2 11.3 11.4 11.5 11.6 11.7 11.8 11.9 12.0 390 Ice Cream Mixes TABLE 70 (Continued). standardizing table for ice cream mix No. 5 testing r 10.00% Fat J 10.50% M. S. N. F. 1 14.00% Sugar L .50% Gelatin 34.00% T. S. Basis 1000 pounds of mix. Top and bottom lines: Fat tests. Side columns: S. N. F. tests. In each square: Top figure : Pounds butter. Center figure: Pounds water. Bottom figure: Pounds sklra -mi 11; powder. (Blanks inilicate none of kind required.) 10.8 10 9 11 .0 111 11 2 11.3 11 .4 11 .5 11.6 11.7 11.8 11 .9 12.00 25.11 62 8.3 69 9.5 77 10. 6 85 11.8 92 13.0 100 14.2 107 15.4 115 16.6 123 17.7 131 18.9 138 20.1 146 21.3 154 22.5 25.11 25.22 63 7.1 70 8.3 78 9.5 86 10.6 93 11.8 101 13.0 108 14.2 116 15.4 124 16.6 132 17.7 139 18.9 147 20.1 155 21.3 25.22 25.33 64 5.9 71 7.1 79 8.3 87 9.5 94 10.6 102 11.8 109 13.0 117 14.2 125 15.4 133 16.6 140 17.7 148 18.9 156 20.1 25.33 25.44 65 4.7 72 5.9 80 7.1 88 8.3 95 9.5 103 10.6 110 U.8 118 13.0 126 14.2 133 15.4 141 16.6 148 17.7 157 18.9 25.44 25.55 66 3.5 73 4.7 81 5.9 89 7.1 96 8.3 104 9.5 111 10.6 119 11.8 127 13.0 134 14.2 142 15.4 149 16.6 158 17.7 25.55 25 66 67 2.4 74 3.5 82 4.7 90 5.9 97 7.1 105 8.3 112 9.5 120 10.6 128 11.8 135 13.0 143 14.2 150 15.4 158 16.6 25 66 25.77 68 1.2 75 2.4 83 3.5 91 4.7 98 5.9 106 7.1 113 8.3 121 9.5 129 10.6 136 11.8 144 13.0 151 14.2 159 15.4 25.77 25.88 69 76 1.2 84 2.4 92 3.5 99 4.7 107 5.9 114 7.1 122 8.3 130 9.5 137 10.6 145 11.8 152 13.0 160 14.2 25.88 25 99 1.2 76 77 85 1.2 93 2.4 100 3.5 108 4.7 115 5.9 123 7.1 131 8.3 138 9.5 146 10.6 153 11.8 161 13.0 25 99 26 10 3.4 84 1.2 85 86 94 1.2 101 2.4 109 3.5 116 4.7 124 5.9 132 7.1 139 8.3 147 9.5 154 10.6 162 11.8 26.10 26.21 3.7 92 3.4 93 1.2 94 95 102 1.2 110 2.4 117 3.5 125 4.7 133 5.9 140 7.1 148 8.3 155 9.5 163 10.6 26.21 26.32 4.9 99 3.7 100 3.4 101 1.2 102 103 111 1.2 118 2.4 126 3.5 134 4.7 141 5.9 149 7.1 156 8.3 164 9.5 26.32 26 43 26 43 6.1 107 4.9 108 3.7 109 3.4 110 1.2 111 112 119 1.2 127 2.4 135 3.5 142 4.7 150 5.9 157 7.1 165 8.3 26.54 7.4 114 6.1 115 4.9 116 3.7 117 3.4 118 1.2 119 120 128 1.2 136 2.4 143 3.5 151 4.7 158 5.9 166 7.1 26.54 26.65 8.6 122 7.4 123 6.1 124 4.9 125 3.7 126 3.4 127 1.2 128 129 137 1.2 144 2.4 152 3.5 159 4.7 167 5.9 26.65 26.76 9.8 130 8.6 131 7.4 132 6.1 133 4.9 134 3.7 135 3.4 136 1.2 137 138 145 1.2 153 2.4 160 3.5 168 4.7 26.76 26.87 11.0 136 9.8 137 8.6 138 7.4 140 6.1 141 4.9 142 3.7 143 3.4 144 1.2 145 146 154 1.2 161 2.4 169 3.5 26.87 26.98 12.3 145 11.0 146 9.8 147 8.6 148 7.4 149 6.1 150 4.9 151 3.7 152 3.4 153 1.2 154 155 162 1.2 170 2.4 26.98 27 09 13.5 152 12.3 153 11.0 154 9.8 155 8.6 156 7.4 157 6.1 158 4.9 159 3.7 160 3.4 161 1.2 162 163 171 1.2 27 09 27 20 14.7 160 13.5 161 12.3 162 11.0 163 9.8 164 8.6 165 7.4 166 6.1 167 4.9 16S 3.7 169 2.4 170 1.2 171 172 27.20 10.8 10.9 11.0 11.1 11.2 11.3 114 115 11.6 11.7 11.8 11.9 12.00 Compositions op Mixes 391 standardizing table for ice cream mix No. 6 testing : 12.00% Pat S.50% M. S. N. F. 14.00% Sugar L .50% Gelatin 35.00% T. S. TABLE 71. Basis 1000 pounds of mix. Top and bottom lines : Fat tests. Side columns : S. N. F. tests. In each square: Top figure: Pounds butter. Center figure: Pounds water. Bottom figure: Pounds skim -milk powder. (Blanks indicate none of kind required.) 10.0 10.1 10.2 29.7 19.9 10.3 10.4 10.5 10.6 10.7 10.8 10 9 11.0 11.1 11 .2 (A) 21.50 32.6 (F) 21.2 31.1 21.0 28.2 19.8 26.7 20.6 25.2 20.4 23.8 20.3 22.3 20.1 20.8 19.9 19.3 19.8 17.9 19.7 16.4 19.5 14.9 19.3 21.50 21.57 32.4 20.7 30.9 20.5 29.5 20.3 28.0 20.2 26.5 20.1 25.0 20.0 23.6 19.8 22.1 19.6 20.6 19.4 19.1 19.2 17.7 19.1 16.2 18.9 14.7 18.7 21.57 21 65 32.3 19.8 30.8 19.6 29.3 19.5 27.9 19.4 26.4 19.3 24.9 19.1 23.4 19.0 22.0 18.8 20.5 18.6 19.0 18.5 17.5 18.3 16.1 18.1 14.6 17.9 21.65 21.72 32.2 18.8 30.6 18.6 29.1 18.5 27.7 18.3 26.2 18.1 24.7 18.0 23.3 17.9 21.8 17.8 20.4 17.6 18.9 17.5 17.3 17.3 15.9 17.1 14.4 17.0 21 .72 21 80 32.0 17.9 30.5 17.7 29.0 17.6 27.6 17.4 26.1 17.3 24.6 17.1 23.2 17.0 21.7 16.8 20.3 16.7 18.7 16.5 17.2 16.3 15.8 16.2 14.3 16.0 21.80 21.87 31.8 17.0 30.3 16.8 28.9 16.7 27.5 16.5 25.9 16.4 24.5 16.3 23.0 16.1 21.5 15.9 20.1 15.8 18.6 15.6 17.0 15.5 15.6 15.3 14.1 15.1 21.87 21 95 31.6 16.1 30.2 16.0 28.8 15.8 27.3 15.6 25.8 15.4 24.3 15.3 22.9 15.1 21.4 15.0 20.0 14.8 18.5 14.7 16.9 14.5 15.5 14.4 13.9 14.2 21 95 22 02 31.5 15.1 31.3 14.2 30.0 15.0 28.6 14.8 27.2 14.7 25.6 14.5 24.2 14.4 22.7 14.3 21.2 14.1 19.8 14.0 18.3 13.8 16.7 13.7 15.3 13.5 13.7 13.3 22.02 22 10 29.9 14.0 28.5 13.9 27.0 13.7 25.5 13.6 24.1 13.4 22.6 13.3 21.1 13.1 19.7 13.0 18.2 12.8 16.5 12.7 15.2 12.5 13.6 12.4 22 10 22 17 31.1 13.3 29.8 13.2 28.3 13.0 26.9 12.8 25.3 12.6 24.0 12.5 22.5 12.3 20.9 12.1 19.6 11.9 18.0 11.8 16.4 11.6 15.0 11.5 13.5 11.3 22.17 22 25 31.0 12.4 29.6 12.2 28.2 12.1 26.8 11.9 25.2 11.8 23.8 11.6 22.3 11.4 20.8 U.3 19.4 11.1 17.8 11.0 16.4 10.8 14.9 10.6 13.3 10.5 22.25 22 32 30.9 11.4 29.5 11.3 28.0 11.2 26.6 11,0 25.0 10.9 23.7 10.7 22.2 10.5 20.6 10.3 19.3 10.1 17.7 10.0 16.2 9.9 14.8 9.7 13.2 9.5 22 32 22 40 30.7 10.5 29.3 10.3 27.9 10.2 26.5 10.0 24.8 9.8 23.5 9.6 22.0 9.5 20.5 9.3 19.1 9.1 17.5 9.0 16.0 8.9 14.6 8.7 13.0 8.6 22.40 22.47 22.55 30.6 9.6 29.1 9.4 27.7 9.3 26.3 9.1 24.6 9.0 23.3 8.9 21.7 8.7 20.3 8.6 19.0 8.4 17.3 8.2 15.9 8.1 14.5 7.9 12.9 7.8 22.47 30.4 8.7 29.0 8.5 27.6 8.4 26.2 8.2 24.5 8.0 23.1 7.9 21.5 7.7 20.2 7.6 18.8 7.4 17.2 7.2 15.8 7.1 14.3 6.9 12.7 6.8 22.55 22 62 30.3 7.7 28.9 7.5 27.4 7.3 26.0 7.1 24.3 7.0 23.0 6.9 21.4 6.7 20.0 6.5 18.6 6.4 17.0 6.2 15.6 6.0 14.2 5.9 12.5 5.8 22 62 22 70 22.77 22 85 30.1 6.8 28.7 6.6 27.3 6.5 25.8 6.4 24.2 6.2 22.8 6.0 21.2 5.9 19.8 5.7 18.4 5.5 16.9 5.4 15.4 5.3 14.0 5.1 12.4 5.0 22.70 30.0 5.9 28.5 5.7 27.1 5.5 25.7 5.4 24.0 5.2 22.6 5.1 21.0 4.9 19.7 4.7 18.2 4.6 16.7 4.5 15.3 4.3 13.8 4.2 12.3 4.0 22.77 29.8 5.0 28.3 4.8 26.9 4.7 25.5 4.5 23.9 4.3 22.5 4.1 20.9 4.0 19.5 3.9 18.0 3.7 16.6 3.5 15.2 3.4 13.7 3.2 12.2 3.1 22.85 22 92 29.7 4.0 28.2 3.8 26.8 3.6 25.3 3.5 23.7 3.4 22.3 3.2 20.7 3.1 19.4 2.9 17.9 2.8 16.4 2.6 15.0 2.5 13.5 2.3 12.0 2.1 22 92 23 00 29.5 (E) 3.1 28.0 2.9 26.6 2.8 25.1 2.6 23.6 2.5 22.1 2.3 20.6 2.2 19.2 2.0 17.7 1.9 16.2 1.7 14.8 1.6 13.3 1.4 11.8 1.2 23 00 10 10.1 10.2 10.3 10.4 10.5 10.6 10.7 10 8 10 9 11.0 11.1 11.2 392 Ice; Cream Mixes standardizing table for ice cream mix No. 6 testing: TABLE 71 (Continued). 12.00% Fat 8.50% M. S. N. F. 14.00% Sugar .50% Gelatin 35.00% T. S. Basis 1000 ijounds of mix. Top and bottom lines: Tat tests. Side columns: S. N. F. tests. In each square : Top figure. Pounds butter. Center figure: Pounds water. Bottom figure: Pounds skim -milk powder. (Blanks inilicate none of kind required.) 10.0 10 1 10.2 10.3 10.4 10.5 10 6 10.7 10.8 10.9 11.0 11.1 11 .2 23.07 29.3 2.2 27.9 2.0 26.4 1.9 25.0 1.7 23.5 1.6 22.0 1.4 20.4 1.3 19.0 1.1 17.5 1.0 16.0 .8 16.6 .7 13.1 .5 1.9 .3 23.07 23.15 29.2 1.2 27.7 1.0 26.3 .9 24.8 .7 23.3 .6 21.8 .4 20.3 .3 18.8 .1 17.3 .0 16.1 1 14.8 2 13.6 3 12.4 4 23.15 23.22 29.0 .3 27.6 .2 26.1 .0 24.7 1 23.5 2 22.2 3 21.0 4 19.8 5 18.. 5 6 17.3 7 16.1 8 14.8 9 13 6 10 23.22 23.30 29.6 3 (K) 28.4 4 27.2 5 25.9 6 24.7 7 23.5 8 22.2 9 21.0 10 19.8 11 18.5 12 17.3 13 16.1 14 14.8 15 23.30 23.37 30.9 9 29.6 10 28.4 11 27.2 12 25.9 13 24.7 14 23.5 15 22.2 17 21.0 18 19.8 19 18.5 20 17.3 21 16,1 22 23.37 23.45 32.1 15 30.9 16 29.6 17 28.4 18 27.2 19 25.9 20 24.7 21 23.5 22 22.2 24 21 25 19.8 26 18.5 27 17.3 28 23.45 23.52 33.3 21 32.1 22 30.9 23 29.6 24 28.4 25 27.2 26 25.9 27 24.7 28 23.5 29 22.2 30 21.0 32 19.8 33 18.5 34 23 52 23 60 34.6 28 33.3 29 32.1 30 30.9 31 29.6 32 28.4 32 27.2 33 25.9 34 24.7 35 23.5 36 22.2 37 21.0 38 19.8 40 23.60 23.67 35.8 34 34.6 35 33.3 36 32.1 37 30. 9 38 29.6 39 28.4 40 27.2 41 25.9 42 24.7 43 23.5 44 22,2 45 21.0 46 23.67 23.75 37.1 40 35.8 41 34.6 42 33.3 43 32.1 44 30.9 45 29.6 46 28.4 47 27.2 48 25.9 49 24.7 50 23.5 51 22.2 52 23.75 23.82 38.3 46 37.1 47 35.8 48 34.6 49 33.3 50 32.1 51 30.9 52 29.6 53 28.4 54 27.2 55 25.9 57 24.7 58 23.5 59 23.82 23 90 39.5 52 38.3 53 37.1 54 35.8 55 34.6 56 33.3 57 32.1 58 30.9 59 29 6 60 28.4 61 27.2 62 25.9 64 24.7 65 23 90 23.97 40.8 58 39.5 59 38.3 60 37.1 61 35.8 62 34.6 63 33.3 64 32.1 65 30.9 66 29.6 67 28.4 68 27.2 70 25.9 71 23.97 24 05 42.0 64 40.8 65 39.5 66 38.3 67 37.1 68 35.8 69 34.6 70 33.3 71 32.1 72 30.9 73 29.6 74 28.4 75 27,2 76 24 05 24.12 43.2 70 42 71 40.8 72 39.5 73 38.3 74 37.1 75 35.8 76 34.6 77 33.3 78 32.1 79 30.9 80 29.6 81 28,4 83 24 12 24.20 44.5 77 43.2 78 42.0 79 40 8 80 39.5 81 38.3 82 37.1 83 35.8 84 34.6 85 33.3 86 32.1 87 30.9 88 29 6 89 24 20 24.27 45.7 83 44.5 84 43.2 85 42.0 86 40.8 87 39.5 88 38.3 89 37.1 90 35,8 91 34,6 92 33.3 93 32.1 94 30,9 95 24 27 24.35 46.9 89 45.7 90 44.5 91 43.2 92 42.0 93 40 8 94 39.5 95 38.3 96 37.1 97 35,8 98 34,6 99 33 3 100 32 1 101 24.35 24 42 48.2 95 46.9 96 45.7 97 44.5 98 43.2 99 42 100 40 8 101 39.5 102 38.3 103 37,1 104 35,8 106 34 6 107 33 3 108 24 42 24 50 49,4 101 48.2 102 46.9 103 45,7 104 44.5 105 43.2 106 42.0 107 40,8 108 39.5 109 38,3 110 37,1 111 35.8 112 34.6 113 24,50 10 10 1 10.2 10 3 10 4 10.5 10.6 10 7 10 8 10 9 11 11 1 11.2 Compositions of Mixes 393 TABLE 71 (Continued). standardizing table -for ice rream mix No. 6 testing: 12.007(r Fat 8.50%- M. S. N. F. 14.00% Sugar .50'7r Gelatin Sr^OO-rr T. S. Basis lonn iiouiids of mix. Top and bottom lines: Fat tests. Side columns: S. N. F. tests. In each square: Top figure: Pounds butter. Center figure: Pounds water. Bottom figure: Pounds skim-mllk powder. (Bluiiks indicate none of kind required. 113 114 115 11 6 11 7 11 8 11 9 12 12 1 12 2 12 3 12 4 12.5 12 6 21.50 1,3.4 19 1 11.9 19.0 10.4 18.8 9.0 18.7 7.5 18.5 6. 1 18.4 4.6 18.3 3 1 (D) 18.1 1.7 17.9 .2 17.8 (I) 6 18.4 12 19.3 19 20 25 20.9 21.50 21.57 13.2 18.6 11.7 18.4 10.2 18.3 8.9 18.2 7.3 18.0 5.9 17.9 4.4 17.8 2.9 17.6 1.5 17.4 .0 17.2 7 17.7 13 18.5 20 19.3 26 20.0 21.57 21 .65 13.1 17.8 11.5 17.6 10.1 17.5 8.7 17.3 7.2 17.2 5.8 17.0 4.3 16.8 2.8 16.7 1.4 16.5 1 16.1 8 16.9 13 17.7 20 18.5 26 19.3 21 .65 21.72 13.0 16.8 11.3 16.7 10.0 16.5 8.6 16.4 7.0 16.2 5.7 16.0 4.1 15.9 2.6 15.7 1.2 15.5 2 15.2 8 16.1 14 16.9 21 17.7 26 18.5 21 .72 21.80 12.8 15.9 11.1 15.7 9.8 15.6 8.4 15.5 6.8 15.3 5.5 15.2 4.0 15.0 2.5 14.8 1.1 14.6 2 14.4 9 15.2 15 16.1 22 16.9 27 17.7 21 80 21 .87 21 95 12.6 15.0 11.0 14.8 9.6 14.7 8.3 14.5 6.7 14.4 5.4 14.2 3.8 14.1 2.3 13.9 9. 13.7 3 13.6 10 14.4 15 15.2 22 16.1 28 16.9 21 87 12.5 14.0 10.9 13.9 9.5 13.7 8.1 13.6 6.6 13.5 5.3 13.3 3.6 13.2 2.2 13.0 .8 12.8 4 12.8 10 13.6 16 14.4 23 15.2 29 16.1 21.95 22 02 12.3 13.1 10.7 12.9 9.4 12.8 7.9 12.6 6.4 12.5 5.1 12.3 3.4 12.2 2.0 12.0 .6 11.8 4 12.0 10 12.8 17 13.6 24 14.4 30 15.2 22.02 22 10 12.1 12.2 10.5 12.1 9.2 11.9 7.8 11.8 6.3 11 .6 4.9 11.5 3.3 11.3 1.9 11.1 .5 10.9 5 11.2 11 12.0 17 12.8 24 13.6 30 14.4 22 10 22.17 12.0 11.2 10.4 110 9.1 10.9 7.6 10.8 6.1 10.6 4.8 10.5 3.2 10.3 1.7 10.2 .3 10.0 6 10.4 11 11.2 18 12.0 25 12.8 31 13.6 22.17 22.25 11.9 10.3 10.2 10. 1 8.9 10.0 7.5 9.9 6.0 9.8 4.6 9.6 3.0 9.5 1.6 9.3 .1 9.1 6 9.6 12 10.4 19 11.2 26 12.0 32 12.8 22.25 22 32 11.8 9.4 10.1 9.3 8.8 9.1 7.3 8.9 5.8 8.8 4.5 8.6 2.9 8.5 1.4 8.3 .0 8.2 6 8.8 13 9.6 19 10.4 26 11.2 32 12.0 22.32 22.40 11.7 8.4 10.0 8.3 8.6 8.1 7.2 7.9 5.6 7.8 4.3 7.7 2.7 7.6 1.2 7.4 1 7.2 7 8.0 14 8.8 20 9.6 27 10.4 33 11.2 22.40 22.47 11.5 7.6 9.9 7.5 8.4 7.3 7.0 7.1 5.5 7.0 4.2 6.8 2.6 6.7 1.1 6.5 1 6.4 8 7.2 14 8.0 21 8.8 28 9.6 34 10.4 22.47 22.55 11.3 6.6 9.7 6.5 8.3 6.3 6.9 6.2 5.3 6.0 4.0 5.9 2.4 5.8 .9 5.6 2 5.6 8 6.4 15 7.2 21 8.0 28 8.8 34 9.6 22.55 22.62 11.1 5.6 9.5 5.5 8.2 5.3 6.7 5.2 5.2 5.0 3.7 4.9 2.2 4.8 .8 4.6 3 4.8 9 5.6 16 6.4 22 7.2 29 8.0 35 8.8 22.62 22.70 11.0 4.8 9.4 4.7 8.1 4.5 6.6 4.3 5.0 4.2 3.5 4.0 2.0 3.9 .6 3.7 3 4.0 10 4.8 16 5.6 23 6.4 30 7.2 36 8.0 22.70 22.77 10.8 3.8 9.2 3.7 7.9 3.5 6.5 3.4 4.9 3.3 3.3 3.1 1.9 2.9 .5 2.8 4 3.2 10 4.0 17 4.8 23 5.6 30 6.4 36 7.2 22.77 22 85 10.7 3.0 9.1 2.8 7.7 2.6 6.3 2.5 4.7 2.3 3.2 2.1 1.8 2.0 .3 1.8 5 2.4 11 3.2 18 4.0 24 4.8 31 5.6 37 6.4 22.85 22 92 10.5 2.0 8.9 1.8 7.6 1.7 6.1 1.5 4.6 1.4 3.1 1.2 1.6 1.1 .2 .9 5 1.6 12 2.4 18 3.2 25 4.0 32 4.8 38 5.6 22.92 23.00 10.3 1 .1 8.8 .9 7.4 .8 5.9 .6 4.4 .5 2.9 .3 1.4 .2 (C) 6 .8 12 1.6 19 2.4 25 3.2 32 4.0 38 4.8 23 00 11.3 11.4 11.5 11.6 11.7 11.8 11.9 12.0 12.1 12.2 12.3 12.4 12.5 12.6 394 Ice Cream Mixes TABLE 71 (Continued). standardizing table for ice rream mix No. 6 testing: ' 12.00% Fat S.50% M. S. N. 14.007o Susar .50% Gelatin 35.00 T. S. Basis 1000 pounds of mix. Top and bottom lines: Fat tests. Side columns; S. N. F. tests. In eacii square: Top figure ; Pounds butter. Center figure: Pounds water. Bottom figure: Pounds sliim-milk powder. (Blanlis indicate none of liind required.) 11 .3 11.4 11.5 11.6 11.7 11 8 11.9 12.0 12.1 12.2 12.3 12.4 12.5 12.6 23.07 9.S .2 8.6 .0 7.4 1 6.2 2 4.9 3 3.7 4 2.5 5 1.2 6 7 13 .8 20 1.6 26 2.4 33 3.2 39 4.0 23.07 23 15 11.1 5 9.9 6 8.6 7 7.4 8 6.2 9 4.9 10 3.7 11 2.5 12 1.2 13 14 20 .8 27 1.6 34 2.4 40 3.2 23.15 23.22 12.4 11 11.1 12 9.9 13 8.6 14 7.4 15 6.2 16 4.9 17 3.7 18 2.5 19 1.2 20 21 28 .8 34 1,6 41 2.4 23.22 23.30 13.6 17 12.4 19 11.1 20 9.9 21 8.6 22 7.4 23 6.2 24 4.9 25 3.7 26 2.5 27 1.2 28 29 35 1.8 42 1.6 23.30 23 37 14.8 23 13.6 24 12.4 25 11.1 27 9.9 28 8.6 29 7.4 30 6.2 31 4.9 32 3.7 33 2.5 34 1.2 35 36 42 .8 23.37 23.45 16.1 29 14.8 30 13.6 31 12.4 32 11.1 33 9.8 35 8.6 36 7.4 37 6.2 38 4.9 39 3.7 40 2.5 41 1.2 42 43 23.45 23.52 17.3 35 16.1 36 14.8 37 13.6 38 12.4 39 11.1 40 9.9 42 8.6 43 7.4 44 6.2 45 4.9 46 3.7 47 2.5 48 1.2 49 23.52 23 60 18.5 41 17.3 42 16.1 43 14.8 44 13.6 45 12.4 46 11,1 47 9.9 48 8.6 50 7.4 51 6.2 52 4.9 53 3.7 54 2.5 55 23.60 23.67 19.8 47 18.5 48 17.3 49 16.1 51 14.8 52 13.6 53 12.4 54 11.1 55 9.9 56 8.6 57 7.4 58 6.2 59 4.9 60 3.7 61 23.67 23.75 21.0 '54 19.8 55 18.5 56 17.3 57 16.1 58 14.8 60 13.6 61 12.4 62 11.1 63 9.9 64 8.6 65 7.4 66 6.2 67 4.9 68 23.75 23.82 22.2 60 21.0 61 19.8 62 18.5 63 17.3 64 16.1 65 14.8 67 13.6 68 12.4 69 11.1 70 9.9 71 8.6 72 7.4 73 6.2 74 23.82 23.90 23.5 66 22.2 67 21.0 68 19.8 69 18.5 70 17.3 71 16.1 72 14.8 73 13.6 75 12.4 76 11.1 77 9.9 78 8.6 79 7.4 80 23 90 23.97 24.7 72 23.5 73 22.2 74 21.0 75 19.8 76 18.5 77 17.3 79 16.1 80 14.8 81 13.6 82 12.4 83 11.1 84 9.9 85 8.6 86 23.97 24.05 25.9 77 24.7 78 23.5 80 22.2 81 21.0 82 19.8 83 18.5 84 17.3 85 16.1 86 14.8 87 13.6 88 12.4 90 11.1 91 9.9 92 24.05 24.12 27.2 84 25.9 85 24.7 86 23.5 87 22.2 88 21.0 89 19.8 91 18.5 92 17.3 93 16.1 94 14.8 95 13.6 96 12.4 97 11.1 98 24.12 24.20 28.4 90 27.2 91 25.9 92 24.7 93 23.5 94 22.2 95 21.0 96 19.8 97 18.5 98 17.3 99 16.1 101 14.8 102 13.6 103 12.4 104 24.20 24.27 29.6 96 28.4 97 27.2 98 25.9 100 24.7 101 23.5 102 22.2 103 21.0 104 19.8 105 18.5 106 17.3 107 16.1 108 14.8 109 13.6 110 24.27 24.35 30.9 102 29.6 103 28.4 104 27.2 105 25.9 106 24.7 107 23.5 108 22.2 109 21.0 111 19.8 112 18.5 113 17.3 114 16.1 116 14.8 117 24.35 24.42 32.1 109 30.9 110 29.6 111 28.4 112 27.2 113 25.9 114 24.7 115 23.5 116 22.2 117 21.0 118 19.8 119 18.5 120 17.3 121 16.1 122 24.42 24 50 33.3 114 32.1 116 30.9 117 29.6 118 28.4 119 27.2 120 25.9 121 24.7 122 23.5 123 22.2 124 21 .0 125 19.8 126 18.5 127 17.3 128 24.50 11.3 114 11.5 11 6 11.7 11 .8 11 .9 12.0 12.1 12.2 12.3 12.4 12.5 12.6 Compositions of Mixiis 395 TABLE 71 (Continued). standardizing table for ice cream mix No. 6 testing: 12.00 8.50 14.00 .50 % Fat % M. S. N. 9c Susar % Gelatin SS.OOTf T. S. Basis 1000 pounds of mix. Top and bottom lines: Fat tests. Side columns: S. N. F. tests. In each square: Top figure: Pounds butter. Center figure: Pounds water. Bottom figure: Pounds skim-milk powder. (Blanks indicate none of kind roijuireil. I 12.7 12.8 12.9 13.0 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13 9 14.0 21 50 32 21.7 38 22.5 45 23.2 51 24.1 58 24.9 64 25.7 71 26.5 77 27.3 84 28.1 90 28.9 97 29.7 103 30.5 110 31.3 (H) 116 32.1 21.50 21 .57 33 20.9 39 21.7 46 22.5 52 23.2 59 24.1 65 24.9 72 25.7 78 26.5 85 27.3 91 28.1 98 28.9 104 29.7 111 30.5 117 31.3 21.57 21.65 33 20.0 39 20.9 46 21.7 52 22.5 59 23.2 65 24.1 72 24.9 78 25.7 85 26.5 91 27.3 98 28.1 104 28.9 111 29.7 117 30.5 21.65 21 .72 33 19.3 39 20.0 46 20.9 53 21.7 60 22.5 66 23.2 73 24.1 79 24.9 86 25 . 7 92 26.5 99 27.3 105 28.1 112 28.9 US 29.7 21 .72 21 80 34 18.5 40 19.3 47 20.0 54 20 9 61 21.7 67 22.5 74 23.2 80 24.1 87 24.9 93 25.7 100 26.5 106 27.3 113 28.1 119 28.9 21 80 21 87 35 17.7 41 18.5 48 19.3 54 20.0 61 20.9 67 21.7 74 22.5 SO 23.2 87 24.1 93 24.9 100 25.7 106 26.5 113 27.3 119 28.1 21.87 21 95 36 16.9 42 17.7 49 18.5 55 19.3 62 20.0 68 20.9 75 21.7 81 22.5 88 23.2 94 24.1 101 24.9 107 25.7 114 26.5 120 27.3 21 95 22 02 37 16.1 43 16.9 50 17.7 56 18.5 63 19.3 69 20.0 76 20.9 82 21.7 89 22.5 95 23.2 102 24.1 108 24.9 115 25.7 121 26.5 22 02 22 10 37 15.2 43 16.1 50 16.9 56 17.7 63 18.5 69 19.3 76 20.0 82 20.9 89 21.7 95 22.5 102 23.2 108 24.1 115 24.9 121 25.7 22 10 22 17 38 14.4 44 15.2 51 16.1 57 16.9 64 17.7 70 18.5 77 19.3 83 20.0 90 20.9 96 21.7 103 22.5 109 23.2 116 24.1 122 24.9 22.17 22.25 39 13.6 45 14.4 52 15.2 58 16.1 65 16.9 71 17.7 78 18.5 84 19.3 91 20.0 97 20.9 104 21.7 110 22.5 117 23.2 123 24.1 22.25 22.32 39 12.8 45 13.6 52 14.4 58 15.2 65 16.1 71 16.9 78 17.7 84 18.5 91 19.3 97 20.0 104 20.9 110 21.7 117 22.5 123 23.2 22.32 22.40 40 12.0 46 12.8 53 13.6 59 14.4 66 15.2 72 16.1 79 16.9 85 17.7 92 18.5 98 19.3 105 20.0 111 20.9 118 21.7 124 22.5 22 40 22 47 41 11.2 47 12.0 54 12.8 60 13.6 67 14.4 73 15.2 80 16.1 86 16.9 93 17.7 99 18.5 106 19.3 112 20.0 119 20.9 125 21.7 22.47 22.55 22 62 41 10.4 47 11.2 54 12 60 12.8 67 13.6 73 14.4 80 15.2 86 16.1 93 16.9 99 17.7 106 IS. 5 112 19.3 119 20.0 125 20.9 22.55 42 9.6 48 10.4 55 11.2 61 12.0 68 12.8 74 13.6 81 14.4 87 15.2 94 16.1 100 16.9 107 17.7 113 18.5 120 19.3 126 20.0 22 62 22 70 43 8.8 49 9.6 56 10.4 62 11.2 69 12.0 75 12.8 82 13.6 88 14.4 95 15.2 101 16.1 108 16.9 114 17.7 121 18.5 127 19.3 22 70 22.77 43 8.0 49 8.8 56 9.6 62 10.4 69 11.2 75 12.0 82 12.8 88 13.6 95 14.4 101 15.2 108 16.1 114 16.9 121 17.7 127 18.5 22 77 22.85 44 7.2 50 8.0 57 8.8 63 9.6 70 10.4 76 11.2 83 12.0 89 12.8 96 13.6 102 14.4 109 15.2 115 16.1 122 16.9 128 17.7 22 85 22 92 45 6.4 51 7.2 58 8.0 64 8.8 71 9.6 77 10.4 84 11.2 90 12.0 97 12.8 103 13.6 110 14.4 116 15.2 123 16.1 129 16.9 22 92 23.00 45 5.6 51 6.4 58 7.2 64 8.0 71 8.8 77 9.6 84 10.4 90 11.2 97 12.0 103 12.8 110 13.6 116 14.4 123 15.2 129 16.1 23 00 12.7 12.8 12 9 13 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 14.0 396 Ice CRii:AM Mixes standardizing table for ice cream mix No. 6 testing: TABLE 71 (Continued). 12.00% Fat 8.50% M. S. N. F. 14.00% Sugar .50% Gelatin 35.00% T. S. Basis 1000 DouuUs of ml.x. Top and bottom lines: Fat tests. Side columns: S. N. F. tests. In each square: Top tlgure: Pounds buttei-. Center figure: Pounds water. Bottom figure: Pounds slcim-mlll? powder. (Blanlis indicate none of liind required.) 12 7 12.8 12 9 13 13.1 13 2 13.3 13.4 13 5 13 6 13.7 13.8 13 9 14.0 23.07 46 4.8 52 5.6 59 6.4 65 7.2 72 8.0 79 8.8 85 9.6 91 10.4 98 11.2 104 12.0 111 12.8 117 13.6 124 14.4 130 15.2 23.07 23.15 47 4.0 53 4.8 60 5.6 66 6.4 73 7.2 80 8.0 86 8.8 92 9.6 99 10.4 105 11.2 112 12.0 118 12.8 125 13.6 131 14.4 23.15 23.22 47 3.2 53 4.0 60 4.8 67 5.6 74 6.4 81 7.2 87 8.0 93 8.8 100 9.6 106 10.4 113 11.2 119 12.0 126 12.8 132 13.6 23.22 23.30 47 2.4 54 3.2 61 4.0 67 4.8 74 5.6 81 6.4 87 7.2 93 8.0 100 8.8 106 9.6 113 10.4 119 11.2 126 12 132 12.8 23.30 23.37 48 1.6 55 2.4 61 3.2 68 4.0 74 4.8 82 5.6 88 6.4 94 7.2 101 8.0 107 8.8 114 9.6 120 10.4 127 11.2 133 12.0 23.37 23 45 49 1.8 56 1.6 62 2.4 69 3.2 75 4.0 82 4.8 89 5.6 95 6.4 102 7.2 108 8.0 115 8.8 121 9.6 128 10.4 134 11.2 23 45 23.52 50 56 .8 63 1.6 69 2.4 75 3.2 83 4.0 89 4.8 96 5.6 103 6.4 109 7.2 116 8.0 122 8.8 128 9.6 134 10.4 23.52 23.62 1.2 56 57 63 .8 70 1.6 76 2.4 83 3.2 90 4.0 96 4.8 103 5.6 109 6.4 117 7.2 123 8.0 129 8.8 135 9.6 23 62 23.67 2.5 62 1.2 63 64 71 .8 77 1.6 81 2.4 90 3.2 97 4.0 104 4.8 110 5.6 117 6.4 123 7.2 129 8.0 136 8.8 23 67 23.75 3.7 69 2.5 70 1.2 71 72 78 .8 85 1.6 91 2.4 97 3.2 104 4.0 111 4.8 118 5.6 124 6.4 130 7.2 136 8.0 23 75 23.82 4.9 75 3.7 76 2.5 77 1.2 78 79 85 .8 91 1.6 98 2.4 105 3.2 111 4.0 118 4.8 125 5.6 131 6.4 137 7.2 23.82 23 90 6.2 81 4.9 82 3.7 83 2.5 84 1.2 85 86 92 .8 98 1.6 105 2.4 112 3.2 119 4.0 125 4.8 131 5.6 138 6.4 23 90 23.97 7.4 87 6.2 88 4.9 89 3.7 90 2.5 91 1.2 92 93 99 .8 106 1.6 112 2.4 120 3.2 126 4.0 132 4.8 138 5.6 23 97 24.05 8.6 93 7.4 94 6.2 95 4.9 96 3.7 97 2.5 98 1.2 99 100 106 .8 113 1.6 121 2.4 126 3.2 133 4.0 139 4.8 24 05 24.12 24 20 9.9 99 8.6 100 7.4 101 6.2 102 4.9 103 3.7 104 2 5 105 1.2 106 107 113 .8 121 1.6 127 2.4 134 3.2 140 4.0 24 12 11 105 9.9 106 8.6 107 7.4 108 6.2 109 4.9 110 3.7 HI 2.5 112 1.2 113 114 122 .8 127 1.6 134 2.4 140 3.2 24 20 24.27 12.4 111 11.1 112 9.9 113 8.6 lis 7.4 116 6 2 117 4.9 118 3.7 119 2.5 120 1.2 121 122 128 .8 135 1.6 141 2.4 24.27 24.35 13.6 118 12.4 119 11.1 120 9.9 121 8.6 122 7.4 123 6.2 124 4.9 125 3.7 126 2.5 127 1.2 128 129 135 .8 142 1.6 24 35 24.42 14.8 123 13.6 125 12.4 126 11.1 127 9.9 128 8.6 129 7.4 130 6.2 131 4.9 132 3.7 133 2.5 134 1.2 135 136 142 .8 24 42 24.50 16.1 130 14.8 131 13.6 132 12.4 133 11.1 134 9.9 135 8.6 136 7.4 137 6.2 138 4.9 139 3.7 140 2.5 141 1.2 142 (G) 143 24 50 12 7 12.8 12.9 13 13 1 13.2 13.3 13 4 13 5 13 6 13.7 13.8 13.9 14.0 Compositions op Mixes 397 standardizing table for ice cream mix No. 7 testing: 12.00% Pat 9.50% M. S. N. F 14.00% SuKar .50% Gelatin 36.00% T. S. TABLE 72. Hasis 1000 pouiid.s of mi.\. Top and Ijottom lines : Fat tests. Side columns : S. N. F. tests. 22 33 In each stiuare: Top tigure : Pounds butter Centei figure: Pounds water. Bottom figure: Pounds slclm-mlllt powder. (Blanks indicate none of kind requiied. ) 23 28 23.41 23 49 23 66 23 75 398 Ice Cream Mixes StandardUing table for ice cream mix No. 7 testing: TABLE 72 (Continued). 00% 50% 00% ,50% Fat M. S. N. F. Sugar Gelatin 36.00% T. S. Basis 1000 pounds of mix. Top and bottom lines : Fat tests. Side columns ; S. N. F. tests. In each sauare : Top figure: Pounds butter. Ceiiter figure; Pounds water. Bottom figure: Pounds skim -milk powder. (Blanks Indicate none of kind required.) 10.0 10.1 10 2 10 3 10.4 10.5 10.6 10.7 10.8 10.9 11.0 111 112 24.08 29.4 2.6 27.9 2.4 26.5 2.2 25.0 2.0 23.5 1.8 22.0 1.6 20.5 1.4 19.1 1.2 17.fi 1.1 16.1 1.0 14.6 .8 13.2 .7 11.7 .5 24 08 24.16 29.2 1.6 27.7 1.4 26.3 1.2 24.8 1.0 23.3 .8 21.8 .6 20.3 .4 18.9 .2 17.4 .1 15.9 .0 14.8 1 13.5 2 12.3 3 24.16 24.24 29.0 .5 27.5 .3 26.1 .1 24.7 .0 23.4 1 22.2 2 21.0 3 19.7 4 18.5 5 17.3 6 16.0 7 14.8 8 13.5 9 24.24 24.33 29.6 3 28.4 4 27.1 5 25.9 6 24.7 7 23.4 8 22.2 10 21.0 11 19.7 12 18.5 13 17.3 14 16.0 15 14.8 16 24.33 24.41 30.8 9 29.6 10 28.4 11 27.1 12 25.9 13 24.7 14 23.4 15 22.2 17 21.0 18 19.7 19 18.5 20 17.3 21 16.0 22 24.41 24.49 32.1 15 30.8 16 29.6 17 28.4 18 27.1 19 25.9 20 24.7 21 23.4 22 22.2 24 21.0 25 19.7 26 18.5 27 17.3 28 24.49 24.58 33.3 21 32.1 22 30.8 23 29.6 24 28.4 25 27.1 26 25.9 27 24.7 28 23.4 29 22.2 31 21.0 32 19.7 33 18.5 34 t 24.58 24 66 34.5 27 33.3 28 32.1 29 30.8 30 29.6 31 28.4 32 27.1 33 25.9 34 24.7 35 23.4 36 22.2 38 21.0 39 19.7 40 24 66 24.74 35.7 33 34.5 34 33.3 35 32.1 36 30.8 37 29.6 38 28.4 39 27.1 40 25.9 41 24.7 42 23.4 43 22.2 45 21 46 24.74 24.83 37.0 39 35.7 40 34.5 41 33.3 42 32.1 43 30.8 44 29.6 45 28.4 47 27.1 48 25.9 49 24.7 51 23.4 52 22.2 53 24.83 24.91 38.2 46 37.0 47 35.7 48 34.5 49 33.3 50 32.1 51 30.8 52 29.6 53 28.4 54 27.1 55 25.9 56 24.7 57 23.4 58 24.91 24.99 39.4 52 38.2 53 37.0 54 35.7 55 34.5 56 33.3 57 32.1 58 30.8 59 29.6 60 28.4 61 27.1 62 25.9 63 24.7 64 24.99 25.07 40.7 58 39.4 59 38.2 60 37.0 61 35.7 62 34.5 63 38.3 64 32.1 65 30.8 66 29.6 67 28.4 68 27.1 69 25.9 70 25.07 25.16 41.9 64 40.7 65 39.4 66 38.2 67 37.0 68 35.7 69 34.5 70 33.3 71 32.1 72 30.8 73 29.6 74 28.4 75 27.1 76 25 16 25.24 43.2 70 41.9 71 40.7 72 39.4 73 38.2 74 37.0 75 35.7 76 34.5 77 33.3 78 32.1 79 30.8 80 29.6 81 28.4 82 25 24 25.33 44.4 76 43.2 77 41.9 78 40.7 79 39.4 80 38.2 81 37.0 82 35.7 83 34.5 84 33.3 86 32.1 87 30.8 88 29.6 89 25 33 25.41 45.6 82 44.4 83 43 2 84 41.9 85 40.7 86 39.4 87 38.2 88 37.0 89 35.7 90 34.5 92 33.3 93 32.1 94 30.8 95 25.41 25 49 46.8 88 45.6 89 44.4 90 43.2 91 41.9 92 40.7 93 39.4 94 38.2 95 37.0 96 35.7 97 34.5 98 33.3 10 32.1 101 25 49 25.58 48.1 94 46.8 95 45.6 96 44.4 97 43.2 98 41.9 99 40.7 100 39.4 101 38. 2 102 37.0 103 35.7 104 34.5 106 33.3 107 25.58 25 66 49.3 100 48.1 101 46.8 102 45.6 103 44.4 104 43.2 105 41.9 106 40.7 107 39.4 108 38.2 109 37.0 110 35.7 111 34.5 112 25 66 10 10.1 10 2 10.3 10 4 10.5 10 6 10 7 10.8 10 9 11.0 111 11.2 standardizing table for ice cream mix No. 7 testing: 12.00% Fat 9.507o M. S. N F 14.00ff Sugar .50% Gelatin Compositions of Mixes TABLE 72 (Continued). 399 36.00%, T. S. Basis 1000 pounds of mix. Top and bottom lines' Fat tests. Side columns: S. N. F. tests. In eacti square: Top figure: Pounds butter Center figure: Pounds water Bottom figure: Pounds skim-railk powder. (Blanks indicate none of kind required.) 400 Ice Cream Mixes standardizing table for ice cream mix No. 7 testing: TABLE 72 (Continued). 12.00% Fat 9.50% M. S. N. F. 14.00% Sugar ..50% Gelatin .36.00% T. S. Basis 1000 pouiKis nf mix. Top and bottom Unes: Fat tests. Side columns: S. N. F. tests. In each sfiuare: Top figure: Pounds butter. Center figure: Pounds water. Bottom figure: Pounds skim -milk powder. (Blanks intiicate none of kind required.) 11.3 11.4 11 5 11.6 11.7 11 .8 119 12.0 12.1 12.2 12.3 12 4 12.5 12.6 24.08 10.2 .3 8.7 .1 7.4 1 6.2 2 4.9 3 3.7 4 2.5 6 1.2 6 7 13 .9 19 1.8 26 2.7 33 3.6 39 4.5 24.08 24.16 11.1 4 9.9 5 8.6 6 7.4 7 6.2 8 4.9 9 3.7 10 2.5 1.2 1.2 13 14 20 .9 27 1.8 33 2.7 40 3.6 24.16 24.24 12. 3 10 11.1 12 9.9 13 8.6 14 7.4 15 6.2 16 4.9 17 3.7 18 2.5 19 1.2 20 21 28 .9 34 1.8 40 2.7 24.24 24.33 13.5 18 12.3 19 11.1 20 9.9 21 8.6 22 7.4 23 6.2 24 4.9 25 3.7 26 2.5 27 1.2 28 29 35 .9 41 1.8 24.33 24 41 14.8 23 13.5 24 12.3 26 11.1 27 9.9 28 8.6 29 7.4 30 6.2 31 4.9 32 3.7 33 2.5 34 1.2 35 36 42 .9 24 41 24.49 16.0 29 14.8 30 13.5 31 12.3 33 U.l 34 9.9 35 8.6 36 7.4 37 6.2 38 4.9 39 3.7 40 2.5 41 1.2 42 43 24.49 24.58 17.3 35 16.0 36 14.8 37 13.5 38 12.3 40 111 42 9.9 43 8.6 44 7.4 45 6.2 46 4.9 47 3.7 47 2.5 48 1.2 49 24.58 24.66 18.5 41 17.3 42 16.0 43 14.8 44 13.5 45 12.3 47 11.1 48 9.9 49 8.6 50 7.4 51 6.2 52 4.9 53 3.7 54 2.5 55 24.66 24.74 19.7 47 18.5 48 17.3 49 16.0 50 14.8 51 13.5 52 12.3 54 11. 1 56 9.9 57 8.6 58 7.4 59 6.2 60 4.9 61 3.7 62 24.74 24.83 21.0 54 19.7 55 18.5 56 17.3 57 16.0 58 14.8 59 13.5 61 12.3 62 11.1 63 9.9 64 8.6 65 7.4 66 6.2 67 4.9 68 24 83 24.91 22.2 59 21.0 61 19.7 62 18.5 63 17.3 64 16.0 65 14.8 66 13.5 67 12.3 68 11.1 70 9.9 71 8.6 72 7.4 73 6.2 74 24.91 24.99 23.4 65 22.2 67 21.0 68 19.7 69 18.5 70 17.3 71 16.0 72 14.8 73 13.5 74 12.3 76 U.l 77 9.9 78 8.6 79 7.4 80 24.99 25.07 24.7 71 23.4 72 22.2 74 21.0 75 19.7 76 18.5 77 17.3 78 16.0 79 14.8 80 13.5 81 12.3 83 11.1 84 9.9 85 8.6 86 25.07 25 16 25.9 77 24.7 78 23.4 79 22.2 81 21.0 82 19.7 83 18.5 84 17.3 85 16.0 86 14.8 87 13.5 88 12.3 90 U.l 91 9.9 92 25.16 25.24 27.1 83 25.9 84 24.7 85 23.4 87 22.2 88 21.0 89 19.7 90 18.5 91 17.3 92 16.0 93 14.8 94 13.5 96 12.3 97 U.l 98 25.24 25.33 28.4 90 27.1 91 25.9 92 24.7 93 23.4 94 22.2 96 21.0 97 19.7 98 18.5 99 17.3 100 16.0 101 14.8 102 13.5 103 12.3 105 25.33 25.41 29.6 96 28.4 97 27.1 98 25.9 99 24.7 100 23.4 101 22.2 102 21 103 19.7 104 18.5 105 17.3 106 16.0 107 14.8 109 13.5 110 25.41 25.49 30.8 102 29.6 103 28.4 104 27.1 105 25.9 106 24.7 107 23.4 109 22.2 110 21.0 111 19.7 112 18.5 113 17.3 114 16.0 115 14.8 116 25.49 25.58 32.1 108 30.8 109 29.6 110 28.4 111 27.1 112 25.9 113 24.7 114 23.4 116 22.2 117 21.0 118 19.7 119 18.5 120 17.3 121 16.0 122 25.58 25 66 33.3 114 32.1 116 30.8 116 29.6 117 28.4 118 27.1 119 25.9 120 24.7 121 23,4 122 22.2 124 21.0 125 19.7 126 18.5 127 17.3 128 25.66 11 .3 11.4 11.5 11.6 11.7 11. a 11.9 12.0 12.1 12.2 12.3 12.4 12.5 12 6 Compositions of Mixes 401 TABLE 72 (Continued). ( 12.009^ Pat Uasis 1000 Douiuls of standardizing 1 9.50% M. S. N. F. mix. table for ice 1 14.00% I .50% Sugar Top and bottom lines: cream mix GelaUn Fat tests. No. 7 testing: Side columns : 36.00% T. S. S. N. F. tests. In each square : Top figure : Pounds butter. Center figure: Pounds water. Bottom figure: Pounds sklm-rallk powder. (Blanks indicate none of kind renuired. ) 12.7 12 8 12.9 13.0 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 14.0 22.33 29 24.1 35 25.0 42 25.9 48 26.8 54 27.7 61 28.6 67 29.5 74 30.4 80 31.3 86 32.2 93 33.1 99 33.9 106 34.5 112 35.7 22.33 22.41 30 23.2 36 24.1 43 25.0 49 25.9 55 26.8 62 27.7 68 28.6 75 29.5 81 30.4 87 31.3 94 32.2 100 33.1 107 33.9 113 34.8 22.41 22.50 31 22.3 37 23.2 44 24.1 50 25.0 56 25.9 63 26.8 69 27.7 76 28.6 82 29.5 88 30.4 95 31.3 101 32.2 108 33.1 114 33.9 22.50 22.58 31 21.4 37 22.3 44 23.2 50 24.1 56 25.0 63 25.9 69 26.8 76 27.7 82 28.6 88 29.5 95 30.4 101 31.3 108 32.2 115 33.1 22.58 22.66 32 20.6 38 21.4 45 22.3 51 23.2 57 24.1 64 25.0 70 25.9 77 26.8 83 27.7 89 28.6 96 29.5 102 30.4 109 31.3 115 32.2 22.66 22.75 33 19.7 39 20.6 46 21.4 52 22.3 58 23.2 65 24.1 71 25.0 78 25.9 84 26.8 90 27.7 97 28.6 103 29.5 110 30.4 116 31.3 22.75 22.83 34 18.8 40 19.7 47 20.6 53 21.4 59 22.3 66 23.2 72 24.1 79 25.0 85 25.9 91 26.8 98 27.7 104 28.6 111 29.5 117 30.4 22.83 22.91 34 17.9 40 18.8 47 19.7 53 20.6 59 21.4 66 22.3 72 23.2 79 24.1 85 25.0 91 25.9 98 26.8 104 27.7 111 28.6 118 29.5 22.91 23.00 35 17.0 41 17.9 48 18.8 54 19.7 60 20.6 67 21.4 73 22.3 80 23.2 86 24.1 92 25.0 99 25.9 105 26.8 112 27.7 119 28.6 23.00 23.08 36 16.1 42 17.0 49 17.9 55 18.8 61 19.7 68 20.6 74 21.4 81 22.3 87 23.2 93 24.1 100 25.0 106 25.9 113 26.8 119 27.7 23.08 23.16 37 15.2 43 16.1 50 17.0 56 17.9 62 18.8 69 19.7 75 20.6 82 21.4 88 22.3 94 23.2 101 24.1 107 25.0 114 25.9 120 26.8 23.16 23.25 38 14.3 44 15.2 61 16.1 57 17.0 63 17.9 70 18.8 76 19.7 83 20.6 89 21.4 95 22.3 102 23.2 108 24.1 115 25.0 121 25.9 23.25 23.33 38 13.4 44 14.3 51 15.2 57 16.1 63 17.0 70 17.9 76 18.8 83 19.7 89 20.6 95 21.4 102 22.3 108 23.2 115 24.1 122 25.0 23.33 23.41 39 12.5 45 13.4 52 14.3 58 15.2 64 16.1 71 17.0 77 17.9 84 18.8 90 19.7 96 20.6 103 21.4 109 22.3 116 23.2 123 24.1 23.41 23.49 40 11.6 46 12.5 53 13.4 59 14.3 65 15.2 72 16.1 78 17.0 85 17.9 91 18.8 97 19.7 104 20.6 110 21.4 117 22.3 123 23.2 23.49 23.58 41 10.7 47 11.6 54 12.5 60 13.4 66 14.3 73 15.2 79 16.1 86 17.0 92 17.9 98 18.8 105 19.7 111 20.6 118 21.4 124 22.3 23.58 23.66 41 9.8 48 10.7 54 11.6 60 12.5 67 13.4 74 14.3 79 15.2 87 16.1 93 17.0 99 17.9 106 18.8 112 19.7 119 20.6 125 21.4 23.66 23.75 42 8.9 48 9.8 55 10.7 61 11.6 68 12.5 75 13.4 80 14.3 87 15.2 93 16.1 99 17.0 106 17.9 112 18.8 119 19.7 126 20.6 23.75 23.83 43 8.0 49 8.9 55 9.8 62 10.7 69 11.6 75 12.5 81 13.4 88 14.3 94 15.2 100 16.1 107 17.0 113 17.9 120 18.8 127 19.7 23.83 23.91 44 7.1 50 8.0 56 8.9 63 9.8 70 10.7 76 11.6 82 12.5 89 13.4 95 14.3 101 15.2 108 16.1 114 17.0 121 17.9 128 18.8 23.91 24.00 45 6.3 51 7.1 57 8.0 64 8.9 70 9.8 77 10.7 82 11.6 89 12.5 96 13.4 101 14.3 108 15.2 114 16.1 121 17.0 128 17.9 24.00 12.7 12.8 12.9 13.0 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 14.0 402 Ice Cream Mixes TABLE 72 (Continued). 12.00'?e Fat Dasis 1000 rounds of standardizing 9.50% M. S. N. F. mix. table for ice 14.00% Sugar Top and bottom lines: cream mix .50% Gelatin Fat tests. No. 7 testing: Side columns : 36.00% T. S. S. N. F. tests. In each square: Top figure : Pounds butter. Center figure: Pounds water. Bottom figure: Pornds skim-milk powder. (Blanks Indicate none of kind required.) 12.7 12.8 12.9 13.0 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 14 24.08 45 .5.4 52 6.3 58 7.1 65 8.0 71 8.9 77 9.8 83 10.7 90 11.6 97 12.5 103 13.4 109 14.3 115 15.2 122 16.1 129 17.0 24.08 24.16 46 4.5 52 5.4 59 6.3 66 7.1 72 8.0 78 8.9 84 9.8 91 10.7 98 11.6 104 12.5 110 13.4 116 14.3 123 15.2 130 16.1 24.16 24.24 47 3.6 53 4.5 59 5.4 67 6.3 73 7.1 79 8.0 85 8.9 91 9.8 99 10.7 105 11.6 111 12.5 117 13.4 123 14.3 131 15.2 24.24 24.33 47 2.7 54 3.6 60 4.5 67 5.4 74 6.3 80 7.1 86 8.0 92 8.9 99 9.8 106 10.7 112 11.6 118 12.5 124 13.4 132 14.3 24.33 24.41 48 1.8 54 2.7 61 3.6 68 4.5 74 5.4 81 6.3 87 7.1 93 8.0 100 8.9 106 9.8 113 10.7 119 11.6 124 12.5 133 13.4 24.41 24.49 49 .9 55 1.8 61 2.7 69 3.6 ■ 75 4.5 81 5.4 88 6.3 94 7.1 101 8.0 107 8.9 113 9.8 120 10.7 125 11.6 133 12.5 24.49 24.58 50 56 .9 62 1.8 69 2.7 76 3.6 82 4.5 88 5.4 95 6.3 102 7.1 108 8.0 114 8.9 120 9.8 126 10.7 134 11.6 24.58 24.66 1.2 56 57 63 .9 70 1.8 76 2.7 83 3.6 89 4.5 95 5.4 103 6.3 109 7.1 115 8.0 121 8.9 127 9.8 134 10.7 24.66 24.74 2.6 62 1.2 63 64 71 .9 77 1.8 83 2.7 90 3.6 96 4.5 103 5.4 110 6.3 116 7.1 122 8.0 128 8.9 135 9.8 24.74 24.83 3.7 69 2.5 70 1.2 71 72 78 .9 84 1.8 90 2.7 97 3.6 104 4.5 110 5.4 117 6.3 123 7.1 129 8.0 135 8.9 24.83 24.91 4.9 75 3.7 76 2.5 77 1.2 78 79 85 .9 91 1.8 97 2.7 105 3.6 111 4.5 117 5.4 124 6.3 130 7.1 136 8.0 24.91 24.99 6.2 81 4.9 82 3.7 83 2.5 84 1.2 85 86 92 .9 98 1.8 105 2.7 112 3.6 118 4.5 124 5.4 131 6.3 136 7.1 24.99 25.07 7.4 87 6.2 88 4.9 89 3.7 90 2.5 91 1.2 92 93 99 .9 106 1.8 112 2.7 119 3.6 125 4.5 131 5.4 137 6.3 25.07 25.16 8.6 93 7.4 94 6.2 95 4.9 96 3.7 97 2.5 98 1.2 99 100 107 .9 113 1.8 119 2.7 126 3.6 132 4.5 138 5.4 25.16 25.24 9.9 99 8.6 100 7.4 101 6.2 102 4.9 103 3.7 104 2,5 105 1.2 107 108 114 .9 120 1.8 126 2.7 133 3.6 139 4.5 25.24 25.33 11.1 106 9.9 107 8.6 108 7.4 109 6.2 110 4.9 111 3.7 112 2.5 113 1.2 114 115 121 .9 127 1.8 133 2.7 140 3.6 25.33 25.41 12.3 111 11.1 113 9.9 114 8.6 115 7.4 116 6.2 117 4.9 118 3.7 119 2.5 120 1.2 121 122 128 .9 134 1.8 140 2.7 25.41 25.49 13.5 118 12.3 119 11.1 120 9.9 121 8.6 122 7.4 123 6.2 124 4.9 125 3.7 126 2.5 127 1.2 128 129 135 .9 141 1.8 25.49 25.58 14.8 123 13.5 124 12.3 126 11.1 127 9.9 128 8.6 129 7.4 130 6.2 131 4.9 132 3.7 133 2.5 134 1.2 135 136 142 .9 25.58 25.66 16.0 129 14.8 130 13.5 131 12.3 132 11.1 133 9.9 134 8.6 136 7.4 137 6.2 138 4.9 139 3.7 140 2.5 141 1.2 142 143 25.66 12.7 12.8 12.9 13.0 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 14.0 Compositions of Mixes 403 Standardi2ing table for ice cream mix No. 8 testing: r 16.00% Fat 7.50% M. S. N. F 14.00% Suiiar .50% Gelatin 38.00% T. S. TABLE 73. Basis 1000 pounds of mi.\. Top ana bottom lines- Fat tests. Side oolumns: S. N. F. tests. In eacli square: Top figure: Pounds butter, tenter figure: Pounds water liottora figure: Pounds slcim-milk powder. (Blanlcs indicate none of kind required. ) 404 Ice Cream Mixes TABLE 73 (Continued). standardizing table for Ice cream mix No. 8 testing: r 16.00%' Fat J 7.. 50% M. S. N. I 14.00%. Sugar L .50%! Gelatin 38.00%. T. S. Basis 1000 ijuuiids of mi-v. Top and bottom lines : Fat tests. Side columns : S. N. F. tests. In each square: Top figure: Pounds butter. Center figure: Pounds water. Bottom figure: Pounds slilm-ralilc powder. (Blanics indicate none of Itind required. ) 14.0 14.1 14.2 14.3 14.4 14.5 14.6 14.7 14.8 14 9 15 15.1 15,2 15.3 22 05 31.7 2.4 30.2 2.3 28.6 2.1 27.0 2.0 25.4 1.8 23.8 1.7 22.2 1.5 20.6 1.4 19.0 1.2 17.4 1.1 15.8 .9 14.3 .8 12.6 .6 11.1 .5 22 05 22.10 31.6 1.8 30.0 1.7 28.4 1.5 26.8 1.4 25.2 1.2 23.6 1.1 22.0 .9 20.4 .8 18.9 .6 17.2 .5 15.6 .3 14.1 .2 12.5 .0 11.3 1 22 10 22 15 31.5 1.2 29.9 1.1 28.3 .9 26.7 .8 25.1 .6 23.5 .5 21.9 .3 20.3 .2 18.8 .0 17.5 1 16.3 2 15.0 3 13.8 5 12.5 6 22.15 22.20 31.4 .6 29.7 .5 28.1 .3 26.5 .2 25.0 .0 23.8 1 22.5 2 21.3 3 20.0 4 18.8 5 17.5 6 16.3 8 15.0 9 13.8 10 22.20 22.25 31.3 30.0 1 28.8 2 27.5 3 26.3 4 25.0 5 23.8 6 22.5 7 21.3 8 20.0 9 18.8 10 17.5 11 16.3 13 15.0 14 22 25 22.30 32.5 6 31.3 7 30.0 8 28.8 9 27.5 10 26.3 11 25.0 12 23.8 13 22.5 14 21.3 15 20.0 16 18.8 18 17 5 19 16.3 20 22 30 22.35 33.8 10 32.5 11 31.3 12 30.0 13 28.8 14 27.5 15 26.3 16 25.0 17 23.8 18 22.5 19 21.3 20 20.0 21 18.8 22 17.5 23 22.35 22.40 35.0 14 33.8 15 32.5 16 31.3 17 30.0 18 28.8 19 27.5 20 26.3 21 25.0 22 23.8 23 22.5 24 21.3 25 20,0 26 18.8 27 22.40 22.45 36.3 18 35.0 19 33.8 20 32.5 21 31.3 22 30.0 23 28.8 24 27.5 25 26.3 26 25.0 27 23.8 28 22.5 29 21.3 30 20.0 31 22 45 22.50 37.5 23 36,3 24 35.0 25 33.8 26 32.5 27 31.3 28 30.0 29 28.8 30 27.5 31 26.3 32 25.0 33 23.8 34 22.5 35 21.3 36 22.50 22.55 38.8 27 37.5 28 36.3 29 35.0 30 33.8 31 32.5 32 31.3 33 30.0 34 28.8 35 27.5 36 26.3 37 25.0 38 23.8 39 22.5 40 22.55 22.60 40.0 31 38.8 32 37.5 33 36.3 34 35.0 35 33.8 36 32.5 37 31.3 38 30.0 39 28.8 40 27.5 41 26.3 42 25.0 43 23.8 44 22.60 22.65 41.3 36 40.0 37 38.8 38 37.5 39 36.3 40 35.0 41 33.8 42 32.5 43 31.3 44 30.0 45 38.8 46 27.5 47 26.3 48 25.0 49 22 65 22.70 42.5 40 41.3 41 40.0 42 38.8 43 37.5 44 36.3 45 35.0 46 33.8 47 32.5 48 31.3 49 30 50 28.8 51 27.5 52 26.3 53 22.70 22.75 43.8 44 42.5 45 41.3 46 40.0 47 38.8 48 37.5 49 36.3 50 35.0 51 33.8 52 32.5 53 31.3 54 30 55 28.8 56 27.5 57 22.75 22.80 45.0 48 43.8 49 42.5 50 41.3 51 40.0 52 38.8 53 37.5 54 36.3 55 35.0 56 33.8 57 32.5 58 31.3 59 30.0 60 28.8 61 22.80 22.85 46.3 53 45.0 54 43.8 55 42.5 56 41.3 57 40.0 58 38.8 59 37.5 60 36.3 61 35.0 62 33.8 63 32.5 64 31.3 65 30.0 66 22.85 22.90 47.5 57 46.3 58 45.0 59 43.8 60 42.5 61 41.3 62 40.0 63 38.8 64 37.5 65 36.3 66 35.0 67 33.8 68 32.5 69 31.3 70 22 90 22.95 48.8 61 47.5 62 46.3 63 45.0 64 43.8 65 42.5 66 41.3 67 40.0 68 38.8 69 37.5 70 36.3 71 35.0 72 33.8 73 32.5 74 22 95 23 00 50 65 48.8 66 47.5 67 46.3 68 45 69 43.8 70 42.5 71 41.3 72 40.0 73 38.8 74 37.5 75 36.3 76 35 77 33.8 78 23 00 14 14 1 14 2 14.3 14.4 14.5 14.6 14.7 14.8 14.9 15 15.1 15.2 15.3 Compositions of Mixes 405 TABLE 73 (Continued). tablP inV' i .V""'" -• ^- N. P. I ^m'ix ^""" """'"'' "^ I ^''•^ach square: M/> Q 4„„t: '- •?"%> Lrelatin I Fat tests. ' i^eiuer ngure: Pounds wjitor Standardizing I ^zisO'l M*'s. N. P. I ^mlx ^""" """'"'" °f I ^" '^ich No. 8 testing: Ss.OO'-i T. S. Siiie columns : S. N. F. tests. T}„»v " -„= — -■ -Pounds water. rSr "■ ^'""'"'' ^W'^^-niilk 'Blanks indicate none of kind required. 13.0 12.8 21 05 12.6 10.9 12.4 12.2 ] 21 10 12.4 10.7 11.8 11.6 1 21 IS 12.3 10.6 11 2 11.0 1 406 Ice Cream Mixes TABLE 73 (Continued). [16.00% Fat Standardizing 1 7.50% M. S. N. F, table for ice | 14.00% Sugar cream mix [ .50% Gelatin No. 8 testing: 3S.007(. T. S. Basis 1000 pounds of mix. Top and bottom Unes; Fat tests. Side columns : S. N. F. tests. In eacli square : Top figure : Pounds butter. Center figure: Pounds water. Bottom figure; Pounds slclm-mills powder. (Blanlcs indicate none of liind required.) 15.4 15 5 15.6 15.7 15,8 15 9 16.0 16.1 16.2 16.3 16.4 16.5 16 6 16 7 22.05 9,5 .3 7.9 .2 6,3 .0 5,0 1 3.S 2 2.5 3 1,3 4 5 11 ,5 15 11 20 1,6 25 2 . 2 29 2.7 35 3,3 22 05 22 10 10.0 2 8.8 3 7.5 4 6.3 5 5,0 3,8 8 2.5 9 1,3 10 11 16 .5 20 1.1 26 1.6 30 2.2 35 2.7 22 10 22.15 11.3 7 10,0 8 8.8 9 7.5 10 6,3 11 5,0 12 3.S 13 2,5 14 1,3 15 16 21 .5 26 1.1 30 1.6 36 2.2 22.15 22 20 22 20 12.5 11 11,3 12 10.0 13 8.8 14 7,5 15 6.3 16 5,0 17 3.8 18 2.5 19 1.3 20 21 27 31 1.1 36 1.6 22 25 13.8 15 12.5 16 113 17 10.0 19 8,8 20 7.5 21 6.3 22 5.0 23 3.8 24 2.5 25 1.3 26 27 31 .5 37 1.1 22 25 22.30 15.0 21 13.8 22 12.5 23 11.3 24 10,0 25 8.8 26 7.5 27 6.3 28 5.0 29 3.8 29 2.5 30 1.3 31 32 37 .5 22.30 22.35 16.3 24 15.0 25 13.8 26 12.5 27 11.3 28 10.0 29 8.8 30 7.5 31 6.3 32 5.0 33 3.8 34 2.5 35 1.3 36 37 22 35 22.40 17.5 28 16.3 29 15.0 30 13,8 31 12.5 32 11.3 33 10,0 34 8.8 35 7.5 36 6.3 38 5,0 39 3.8 40 2.5 41 1.3 42 22.40 22.45 18.8 32 17.5 33 16.3 34 15.0 35 13.8 36 12.5 37 11.3 39 10.0 40 8.8 41 7.5 42 6.3 43 5.0 44 3.8 45 2.5 46 22.45 22.50 20.0 37 18.8 38 17.5 39 16.3 40 15.0 41 13.8 42 12.5 43 11.3 44 10.0 45 8.8 46 7.5 47 6.3 48 5.0 49 3.8 50 22 50 22 55 21.3 41 20.0 42 18.8 43 17.5 44 16.3 45 15.0 46 13.8 47 12.5 49 11.3 50 10.0 51 8.8 52 7.5 53 6.3 54 5.0 55 22 55 22 60 22.5 45 21.3 46 20.0 47 18.8 48 17, 5 49 16.3 50 15.0 51 13.8 52 12.5 53 U.3 55 10.0 56 8.8 57 7.5 58 6.3 59 22.60 22 65 23.8 50 22.5 51 21,3 52 20,0 53 18.8 54 17.5 55 16.3 56 15.0 57 13.8 58 12.5 59 11.3 60 10.0 61 8.8 62 7,5 63 22 65 22.70 25.0 54 23.8 55 22,5 56 21,3 57 20.0 58 18.8 59 17.5 60 16.3 62 15.0 63 13.8 64 12.5 65 11.3 66 10.0 67 8.8 68 22 70 22 75 26.3 58 25.0 59 23,8 60 22,5 61 21.3 62 20.0 63 18.8 64 17.5 65 16.3 67 15.0 68 13.8 69 12.5 70 11.3 71 10.0 72 22,75 22 80 27.5 62 26.3 63 25.0 64 23,8 65 22.5 66 21.3 67 20.0 68 18.8 70 17.5 71 16.3 72 15,0 73 13.8 74 12.5 75 11.3 76 22 80 22 85 28.8 67 27.5 68 26.3 69 25,0 70 23.8 71 22.5 72 21.3 73 20.0 74 18.8 75 17.5 76 16,3 77 15.0 79 13.8 80 12.5 81 22 85 22 90 30.0 71 28.8 72 27.5 73 26.3 74 25.0 75 23.8 76 22.5 77 21.3 78 20.0 80 18.8 81 17.5 82 16.3 S3 15.0 84 13.8 85 22 90 22 95 31.3 75 30.3 77 28.8 78 27.5 79 26.3 80 25.0 81 23.8 82 22.5 83 21.3 84 20.0 85 18.8 86 17.5 87 16.3 88 15.0 89 22 95 23 00 32.5 79 31.3 80 30,0 82 28.8 83 27,5 84 26.3 85 25.0 80 23.8 87 22,5 88 21.3 89 20 90 18,8 92 17.5 93 16.3 94 23 00 15.4 15.5 15.6 15 7 15 8 15 9 16 16,1 16.2 16.3 16,4 16 5 16.6 16 7 Compositions of Mixes 407 TABLE 73 (Continued), standardizing table for ice cream mix No. 8 testing: 16.00% Fat 7.50% M. S. N. F. 14.00% Susar .50% Gelatin 38.00% T. S. Basis 1000 pounds of mix. Top and bottom lines : Fat tests. Side columns: S. N. F. tests. In eacii square : Top figure : Pounds butter. Center tigure: Pounds water. Bottom figure: Pounds skim-milk powder. (Blanks indicate none of kind required.) ' 16.8 16 9 17.0 17.1 17.2 17.3 17.4 17.5 17.6 17.7 17.8 17.9 18.0 21 00 29 15.2 34 15.8 39 16.3 43 16.8 48 17.4 53 17.9 58 18.5 63 19.0 68 19.5 72 20.1 77 20.6 82 21.2 87 21.7 21.00 21 05 29 14.7 34 15.2 39 15.8 43 16.3 48 16.8 54 17.4 58 17.9 63 18.5 69 19.0 72 19.5 77 20.1 82 20.6 87 21.2 21 .05 21.10 30 14.1 35 14.7 40 15.2 44 15.8 49 16.3 54 16.8 59 17.4 64 17.9 69 18.5 73 19.0 78 19.5 83 20.1 88 20.6 21 .10 21 15 30 13.6 35 14.1 40 14.7 44 15.2 49 15.8 55 16.3 59 16.8 64 17.4 70 17.9 73 18.5 78 19.0 83 19.5 88 20.1 21.15 21 .20 31 13.0 36 13.6 41 14.1 45 14.7 50 15.2 55 15.8 60 16.3 65 16.8 70 17.4 74 17.9 79 18.5 84 19.0 89 19.5 21.20 21.25 31 12.5 36 13.0 4) 13.6 45 14.1 50 14.7 56 15.2 60 15.8 65 16.3 71 16.8 74 17.4 79 17.9 84 18.5 89 19.0 21 .25 21.30 32 11.9 37 12.5 42 13.0 46 13.6 51 14.1 56 14.7 61 15.2 66 15.8 71 16.3 75 16.8 80 17.4 85 17.9 90 18.5 21.30 21.35 32 U.4 37 11.9 42 12.5 46 13.0 51 13.6 57 14.1 61 14.7 66 15.2 72 15.8 75 16.3 80 16.8 85 17.4 90 17.9 21 .35 21 .40 33 10.9 38 11.4 43 11.9 47 12.5 52 13.0 57 13.6 62 14.1 67 14.7 72 15.2 76 15.8 81 16,3 86 16.8 91 17.4 21.40 1 .45 21.50 33 10.3 38 10.9 43 11.4 47 11.9 52 12.5 58 13.0 62 13.6 67 14.1 73 14.7 76 15.2 81 15.8 86 16.3 91 16.8 21.45 34 9.8 39 10.3 44 10.9 48 11.4 53 11.9 58 12.5 63 13.0 68 13.6 73 14.1 77 14.7 82 15.2 87 15.8 92 16.3 21.50 21 55 34 9.2 39 9.8 44 10.3 48 10.9 53 11.4 59 11.9 63 12.5 68 13.0 74 13.6 77 14.1 82 14.7 87 15.2 92 15.8 21.55 21.60 35 8.7 40 9.2 45 9.8 49 10.3 54 10,9 59 11.4 64 11.9 69 12.5 74 13.0 78 13.6 83 14.1 88 14.7 93 15.2 21.60 21.65 35 8.1 40 8.7 45 9.2 49 9.8 54 10.3 60 10.9 64 11.4 69 11.9 75 12.5 78 13.0 83 13.6 88 14.1 93 14.7 21 .65 21.70 36 7.6 41 8.1 46 8.7 50 9.2 55 9.8 00 10.3 65 10.9 70 11.4 75 11.9 79 12.5 84 13.0 89 13.6 94 14.1 21.70 21.75 36 7.1 41 7.6 46 8.1 50 8.7 55 9.2 61 9.8 65 10.3 70 10.9 76 11.4 79 11.9 84 12.5 89 13.0 94 13.6 21.75 21 80 37 6.5 42 7.1 47 7.6 51 8.1 56 8.7 61 9.2 66 9.8 71 10.3 76 10.9 80 11.4 85 11.9 90 12.5 95 13.0 21 .80 21.85 37 6.0 42 6.5 47 7.1 51 7.6 56 8.1 62 8.7 66 9.2 71 9.8 77 10.3 80 10.9 85 11 .4 90 11.9 95 12.5 21.85 21 90 38 5.4 43 6.0 48 6.5 52 7.1 57 7.6 62 8.1 67 8.7 72 9.2 77 9.8 81 10.3 86 10.9 91 11.4 96 11.9 21.90 21.95 38 4.9 43 5.4 48 6.0 52 6.5 57 7.1 63 7.6 67 8.1 72 8.7 78 9.2 81 9.8 86 10.3 91 10.9 96 U.4 21.95 22.00 39 4.3 44 4.9 49 5.4 53 6.0 58 6 5 63 7.1 68 7.6 73 8.1 78 8.7 82 9.2 87 9.8 92 10.3 97 10.9 22.00 16.8 16.9 17.0 17.1 17.2 17.3 17.4 17.5 17.6 17.7 17.8 17.9 18.0 408 Ice Cream Mixes standardizing table for ice nream mix No. 8 testing: TABLE 73 (Continued). Basis 1000 pounds of mix. Top and bottom lines : Fat tests. Side columns : S. N. F. tests. Ill eacli square: Top figure : Pounds butter. Center flgure: Pounds water. Bottom figure: Pounds skim -milk powder. (Blanks indicate none of kind required.) 16.8 16 9 17.0 17.1 17 2 17.3 17.4 17.5 17 6 17.7 17.8 17.9 18.0 22.05 39 3.8 44 4.3 49 4.9 53 5.4 58 6.0 64 6.5 68 7.1 73 7.6 79 8.1 82 8.7 87 9.2 92 9.8 97 10.3 22.05 22.10 40 3.3 45 3.8 50 4.3 54 4.9 59 5.4 64 6.0 69 6.5 74 7.1 79 7.6 83 8.1 88 8.7 93 9.2 98 9.8 22.10 22.15 40 2.7 45 3.3 50 3.8 54 4.3 59 4.9 65 5.4 69 6.0 74 6.5 80 7.1 83 7.6 88 8.1 93 8.7 99 9.2 22.15 22 20 41 2.2 46 2.7 51 3.3 55 3.8 60 4.3 65 4.9 70 5.4 75 6.0 80 6.5 84 7.1 89 7.6 94 8.1 99 8.7 22 20 22 25 41 1.6 46 2.2 51 2.7 55 3.3 60 3.8 66 4.3 70 4.9 75 5.4 81 6.0 84 6.5 89 7.1 94 7.6 100 8.1 22.25 22.30 42 1.1 47 1.6 52 2.2 56 2.7 61 3.3 66 3.8 71 4.3 76 4.9 81 5.4 85 6.0 90 6.5 95 7.1 100 7.6 22.30 22.35 42 .5 47 1.1 52 1.6 56 2.2 61 2.7 67 3.3 71 3.8 76 4.3 82 4.9 85 5.4 90 6.0 95 6.5 101 7.1 22.35 22.40 43 48 .5 53 1.1 57 1.6 62 2.2 67 2.7 72 3.3 77 3.8 82 4.3 86 4.9 91 5.4 96 6.0 101 6.5 22.40 22.45 1.3 47 48 S3 .5 57 1.1 62 1.6 68 2.2 72 2.7 77 3.3 83 3.8 86 4.3 91 4.9 96 5.4 102 6.0 22.45 22 50 2.5 51 1.3 52 53 58 .5 63 1.1 68 1.6 73 2.2 78 2.7 83 3.3 87 3.8 92 4.3 97 4.9 102 5.4 22.50 22.55 3.8 56 2.5 57 1.3 58 59 63 .5 69 1 1 73 1.6 78 2.2 84 2.7 87 3.3 92 3.8 97 4.3 103 4.9 22.55 22.60 5.0 60 3.8 61 2.5 62 1.3 63 64 69 .5 74 1.1 79 1.6 84 2.2 88 2.7 93 3.3 98 3.8 103 4.3 22 60 22.65 6.3 64 5.0 65 3.8 66 2.5 67 1.3 68 69 74 .5 79 1.1 85 1.6 88 2.2 93 2.7 98 3.3 104 3.8 22.65 22.70 7.5 69 6.3 70 5.0 71 3.8 72 2.5 73 1.3 74 75 80 .6 86 1.1 89 1.6 94 2.2 99 2.7 104 3.3 22.70 22.75 8.8 73 7.5 74 6.3 75 5.0 76 3.8 77 2.5 78 1.3 79 80 85 .5 89 1.1 94 1.6 99 2.2 105 2.7 22.75 22.80 10.0 77 8.8 78 7.5 79 6.3 80 5.0 81 3.8 82 2.6 83 1.3 84 85 90 .5 96 1.1 100 1.6 106 2.2 22 80 22.85 11.3 82 10.0 83 8.8 84 7.5 85 6.3 86 5.0 87 3.8 88 2.5 89 1.3 90 91 95 .6 101 1.1 106 1.6 22.85 22.90 12.5 86 11.3 87 10.0 88 8.8 89 7.5 90 6.3 91 5.0 92 3.8 93 2.5 94 1.3 95 96 101 .6 106 1.1 22 90 22 95 13.8 90 12.5 92 11.3 93 10.0 94 8.8 95 7.5 96 6.3 97 5.0 98 3.8 99 2.5 100 1.3 101 102 107 .5 22.95 23.00 15.0 95 13.8 96 12.5 97 11.3 98 10.0 99 8.8 100 7.6 101 6.3 102 5.0 103 3.8 104 2.5 105 1.3 106 107 23.00 16.8 16.9 17.0 17.1 17.2 17.3 17.4 17.5 17.6 17.7 17.8 17.9 18.0 Compositions of Mixes- TABLE 74. 409 standardizing table for ice cream mix No. 9 testing: flS.00% Fat ' 7.50% W. S. N. F. 1 14.'u0% Sugar L .50% - Gelatin 40.00'; T. s. Basis 1000 jiounds of mi.\. Top and bottom lines ■ Fat tests. .Side colmnns: t^- X F. tests. In each square : Top figure: Pounds Ijutter. Center figure: Pounds water, powder -"• ■^"""'^' sklm-mllk (Blanlis indicate none of Itind required, i 410 Ice Cream Mixes standardizing table for ice cream mix No. 9 testing: TABLE 74 (Continued). r 18.00% Pat I 7.50% M. S. N. P. 1 14.00% Susar L .50% Gelatin 40.00% T. S. Basis 1000 pounds of mix. Top and bottom lines: Pat tests. Side columns : S. N. P. tests. In each square : Top figure: Pounds butter. Center figure: Pounds water. Bottom figure: Pounds skim-milk oowder. (Blanks indicate none of kind required.) 16.0 16 1 16 2 16.3 16.4 16.5 16 6 16.7 16.8 16.9 17.0 17.1 17.2 17.3 22.04 33.6 2.7 i2.0 2.5 30.2 2.4 28.5 2.3 26.8 2.1 25.2 2.0 23.5 1.8 21.8 1.6 20.1 1.4 18.4 1.3 16.7 1.1 15.0 1.0 13.3 .8 11.6 .6 22.04 22.09 33.4 2.2 33.3 1.7 31.8 2.0 30.1 1.9 28.3 1.7 26.6 1.6 25.0 1.4 23.4 1.2 21.7 1.1 19.9 .9 18.2 .8 16.5 .6 14.8 .5 13.1 .3 U.3 1 22 09 23.13 31.6 1.5 29.9 1.4 28.2 1.2 26.4 1.1 24.9 .9 23.2 .7 21.5 .6 19.4 .4 18.0 .2 16.3 1 15.1 2 13.8 3 12.5 4 22.13 22.18 33.1 1.2 31.4 1.0 29.7 .9 28.0 .7 26.3 .6 24.8 .4 22.6 1 21.3 2 20.1 3 18.8 4 17.6 5 16.3 6 15.1 7 13.8 8 22.18 22.22 32.9 .6 31.2 .4 28.4 1 27.6 2 26.4 3 25.1 4 23.8 5 22.6 6 21.3 7 20.1 8 18.8 9 17.6 10 16.3 11 15.1 12 22.22 22.26 32.6 3 31.4 4 30.1 5 28.9 6 27.6 7 26.4 8 25.1 9 23.8 10 22.6 11 21.3 12 20.1 13 18.8 14 17.6 15 16.3 16 22.26 22.31 33.9 7 32.6 8 31.4 9 30.1 10 28.9 11 27.6 12 26.4 13 25.1 14 23.8 15 22.6 16 21.3 17 20.1 18 18.8 19 17.6 20 22 31 22.36 35.1 10 33.9 11 32.6 12 31.4 13 30.1 14 28.9 15 27.6 16 26.4 17 25.1 18 23.8 19 22.6 20 21.3 21 20.1 22 18.8 23 22.36 22.40 36.4 14 35.1 15 33.9 16 32.6 17 31.4 18 30.1 19 28.9 20 27.6 21 26.4 22 25.1 23 23.8 24 22.6 25 21.3 26 20.1 27 22.40 22.44 37.6 17 36.4 18 35.1 19 33.9 20 32.6 21 31.4 22 30.1 23 28.9 24 27.6 25 26.4 26 25.1 27 23.8 28 22.6 30 21.3 31 22.44 22 49 38.9 21 37.6 22 36.4 23 35.1 24 33.9 25 32.6 26 31.4 27 30.1 28 28.9 29 27.6 30 26.4 31 25.1 32 23.8 33 22.6 34 22.49 22.53 40.2 24 38.9 25 37.6 26 36.4 27 35.1 28 33.9 29 32.6 30 31.4 31 30.1 32 28.9 33 27.6 34 26.4 35 25.1 36 23.8 37 22.53 22 58 41.4 28 40.2 29 38.9 30 37.6 31 36.4 32 35.1 33 33.9 34 32.6 35 31.4 36 30.1 37 28.9 38 27.6 39 26.4 40 25.1 41 22.58 22 62 42.7 32 41 .'4 33 40.2 34 38.9 35 37.6 36 36.4 37 35.1 38 33.9 39 32.6 40 31.4 41 30.1 42 28.9 43 27.6 44 26.4 46 22.62 22.67 43.9 36 42.7 37 41.4 38 40.2 39 38.9 40 37.6 41 36.4 42 35.1 43 33.9 44 32.6 45 31.4 46 30.1 47 28.9 48 27.6 49 22.67 22.71 45.2 39 43.9 40 42.7 41 41.4 42 40.2 43 38.4 , 44 37.6 45 36.4 46 35.1 47 33.9 48 32.6 49 31.4 50 30.1 5i 28.9 52 22.71 22.76 46.4 43 45.2 44 43.9 45 42.7 46 41.4 47 40.2 48 38.9 49 37.6 50 36.4 51 35.1 52 33.9 53 32.6 54 31.4 55 30.1 56 22.76 22.80 47.7 47 46.4 48 45 2 49 43. f 50 42.7 51 41.4 52 40.2 53 38.9 54 37.6 55 36.4 56 35.1 57 33.9 58 32.6 59 31.4 60 22.80 22.85 48. S 51 47.7 52 46.4 53 45.2 54 43.9 55 42.7 5€ 41.4 57 40.2 5S 38.(1 59 37. f 60 36.4 61 35.1 62 33.9 63 32.6 64 22.85 22.89 50.2 5-1 48. f 5t 47.7 5C 46.4 5' 45.2 43. £ 5£ 42.7 6C 41.4 61 40.2 62 38. t 6C 37. e 64 36.4 6: 35.1 66 33.9 67 17.3 22 89 16. ( ) 16.1 16.2 16.: 16. 4 16. J 16 « 16.- 16. f 16. J 17. t 17.1 17.2 Compositions of Mixes 411 TABLE 74 (Continued). standardizing table for ice cream mix No. 9 testing: r 18.00% Fat J 7.50% M. S. N. 1 14,00% Sugar L .50% Gelatin 40.007c T. S. Basis 1000 rounds of mix. Top and bottom lines: Fat tests. Side columns: S. N. F. tests. In each square: Top figure : Pounds butter. Center figure: Pounds water. Bottom figure: Pounds skira-milk powder. (Blanlts indicate none of kind required.) 17.4 17.5 17.6 17 7 17.8 17 9 18.0 18.1 18.2 18.3 18.4 18,5 18.6 18.7 21.11 13.4 11.8 11.7 11.6 10.0 11.5 8.4 11.3 6.7 11.2 5.0 11.0 3.3 10.9 1.6 10.7 .0 10.4 4 10.9 9 11.4 13 11.8 17 12.3 22 12.8 21.11 21.16 13.2 11.2 11.5 11.0 9.8 10.9 8.2 10.7 6.5 10.6 4.8 10.4 3.1 10.3 1.4 10.1 1 9.9 4 10.4 9 10.9 13 11.4 17 11.8 22 12.3 21 .16 21 20 13.0 10.5 11.3 10.4 9.6 10.3 8.0 10.2 6.3 10.1 4.6 10.0 2.9 9.8 1.2 9.6 1 9.5 5 9.9 10 10.4 14 10.9 18 11.4 23 11.8 21 20 21 .24 12.9 10.2 11.2 10. 1 9.5 9.9 7.9 9.7 6.2 9.6 4.5 9.4 2.8 9.3 1.1 9.1 2 9.0 5 9.5 10 9.9 14 10.4 18 10.9 23 11.4 21.24 21.29 12.7 9.6 11.0 9.4 9.3 9.3 7.7 9.1 6.0 9.0 4.3 8.9 2.6 8.7 .9 8.5 2 8.5 6 9.0 11 9.5 15 9.9 18 10.4 24 10.9 21.29 21.33 12.6 9.1 10.9 8.9 9.2 8.8 7.6 8.7 5.9 8.5 4.2 8.3 2.5 8.2 .8 8.0 3 8.0 6 8.5 11 9.0 15 9.5 19 9.9 24 10.4 21.33 21.38 12.4 8.7 10.7 8.6 9.0 8.4 7.4 8.2 5.7 8.0 4.0 7.8 2.3 7.6 .6 7.4 3 7.6 7 8.0 12 8.5 15 9.0 19 9.5 24 9.9 21 38 21 .42 12.3 8.0 10. 6 7.9 8.9 7.7 7.3 7.6 5.6 7.4 3.8 7.3 2.1 7.1 .4 7.0 4 7.1 7 7.6 12 8.0 16 8.5 20 9.0 25 9.5 21.42 21.47 12.1 7.4 10.4 7.2 8.7 7.1 7.1 6.8 5.4 6.7 3.7 6.6 2.0 6.5 .3 6.3 4 6.7 8 7.1 12 7.6 16 8.0 20 8.5 25 9.0 21.47 21.51 11.9 7.0 10.2 6.8 8.5 6.7 6.9 6.5 5.2 6.4 3.5 6.2 1.8 6.0 .1 5.8 5 6.2 8 6.7 13 7.1 17 7.6 21 8.0 26 8.5 21.51 21.56 11.8 6.2 10.1 6.0 8.4 5.9 6.8 5.7 5.1 5.6 3.4 5.5 1.7 5.4 5.2 5 5.7 9 6.2 13 6.7 17 7.1 21 7.6 26 8.0 21.56 21.60 11.6 5.9 9.9 5.7 8.2 5.6 6.6 5.4 4.9 5.2 3.2 5.0 1.5 4.9 1 4.7 6 5.2 9 5.7 14 6.2 17 6.7 21 7.1 26 7.6 21.60 21.64 11.5 5.3 9.8 5.1 8.1 5.0 6.5 4.8 4.8 4.6 3.0 4.5 1.3 4.3 1 4.2 6 4.7 9 5.2 14 5.7 18 6.2 22 6.7 27 7.1 21 .64 21.69 11.3 4.6 9.6 4.5 7.9 4.4 6.3 4.3 4.6 4.2 2.9 4.0 1.2 3.8 2 3.8 6 4.2 10 4.7 15 5.2 18 5.7 22 6.2 27 6.7 21.69 21.73 11.1 4.2 9.4 4.0 7.7 3.9 6.1 3.7 4.4 3.6 2.7 3.4 1.0 3.3 2 3.3 7 3.8 10 4.2 15 4.7 19 5.2 23 5.7 28 6.2 21.73 21.78 11.0 3.6 9.3 3.5 7.6 3.3 6.0 3.1 4.3 3.0 2.5 2.9 .8 2.7 3 2.8 7 3.3 11 3.8 15 4.2 19 4.7 23 5.2 28 5.7 21.78 21.82 10.8 3.1 9.1 2.9 7.4 2.8 5.8 2.6 4.1 2.5 2.4 2.4 .7 2.2 3 2.4 8 2.8 11 3.3 16 3.8 19 4.2 23 4.7 28 5.2 21.82 21 87 10.6 2.5 8.9 2.3 7.2 2.1 5.6 2.0 3.9 1.9 2.2 1.8 .5 1.6 4 1,9 8 2.4 11 2.8 16 3.3 20 3.8 24 4.2 29 4.7 21.87 21 91 10.5 2.1 8.8 1.9 7.1 1.7 5.5 1.6 3.8 1.4 2.0 1.3 .3 1.1 4 1.4 9 1.9 12 2.4 17 2.8 20 3.3 24 3.8 29 4.2 21 .91 21 .96 10.4 l.S 8.6 1.3 7.0 1.1 5.3 1.0 3.6 .8 1.9 .7 .2 .5 4 .9 9 1.4 12 1.9 17 2.4 21 2.8 25 3.3 30 3.8 21.96 22.00 10 2 10 8.4 .8 6.8 .6 5.1 .5 3.4 .3 1.7 .2 5 .5 9 .9 13 1.4 17 1.9 21 2.4 25 2.8 30 3.3 22.00 17 4 17.5 17.6 17.7 17.8 17.9 18.0 18.1 18.2 18.3 18.4 18 5 18.6 18.7 412 Ice: Cre:am Mixes TABLE 74 (Continued). r IS.OO^r Fat Standardizing J 7.50% M. S. N. F. table for ice I 14.00% Sugar L .50% Gelatin 40.00% T. S. Kasis 1000 pounds of mix. Top and bottom lines: Fat tests. Side columns: S. N. V. tests. In each square : Top figure: Pounds butter. Center figure: Pounds water. Bottom figure: Pounds sklm-mllk powder. (Blanks indicate none of kind required.) 17.4 17 5 17 6 17.7 17.8 17 9 18.0 18.1 18.2 18.3 18.4 18.5 18 6 18.7 22 04 10.0 .5 8.2 .3 6.6 .1 5.0 1 3.8 2 2.5 3 1.3 4 5 10 . 5 13 .9 18 1.4 22 1.9 26 2.4 31 2.8 22 04 22.09 10.0 2 8.8 3 7.5 4 6.3 5 5.0 6 3.8 7 2.5 8 1.3 9 10 14 .6 18 .9 22 1.4 26 1.9 31 2.4 22.09 22.13 11.3 5 10.0 6 8.8 7 7.5 8 6.3 9 6.0 10 3.8 11 2.5 12 1.3 13 14 19 .5 23 .9 27 1.4 32 1.9 22 13 22.18 22.22 12.5 9 11.3 10 10.0 11 8.8 12 7.5 13 6.3 14 6.0 15 3.8 16 2.6 17 1.3 18 19 24 .6 28 .9 33 1.4 22 18 13.8 13 12.5 14 11.3 15 10.0 16 8.8 17 7.6 18 6.3 19 5.0 20 3,8 21 2.6 22 1.3 23 24 28 .5 33 .9 22.22 22.26 15.1 17 13.8 18 12.5 19 11.3 20 10.0 21 8.8 22 7.5 23 6.3 24 5.0 26 3.8 26 2.5 27 1.3 28 29 34 .5 22.26 22.31 16.3 21 15.1 22 13.8 23 12.5 24 11.3 25 10.0 26 8.8 27 7.5 28 6.3 29 5.0 30 3.8 31 2.5 32 1.3 33 34 22.31 22.36 17.6 24 16.3 25 15.1 26 13.8 27 12.5 28 11.3 29 10.0 30 8.8 31 7.5 32 6.3 33 5.0 34 3.8 36 2.5 36 1.3 37 22.36 22.40 18.8 28 17.6 29 16.3 30 15.1 31 13.8 32 12.5 33 11.3 34 10.0 36 8.8 37 7.5 38 6.3 39 5.0 40 3.8 41 2.6 42 22.40 22.44 20.1 32 18.8 33 17.6 34 16.3 35 15.1 36 13.8 37 12.5 38 11.3 39 10.0 40 8.8 41 7.6 42 6.3 43 5.0 44 3.8 45 22.44 22 49 21.3 35 20.1 36 18.8 37 17.6 38 16.3 39 15.1 40 13.8 41 12.5 42 11.3 43 10.0 44 8.8 45 7.5 46 6.3 47 6.0 48 22.49 22.53 22.6 39 21.3 40 20.1 41 18.8 42 17.6 43 16.3 44 15.1 45 13.8 46 12.5 47 11.3 48 10.0 49 8.8 50 7.5 51 6.3 52 22.53 22.58 22.62 23.8 42 22.6 43 21.3 44 20.1 45 18.8 46 17.6 47 16.3 48 15.1 49 13.8 51 12.6 62 11.3 53 10.0 54 8.8 55 7.5 56 22.58 25.1 47 23.8 48 22.6 49 21.3 50 20.1 51 18.8 62 17.6 53 16.3 54 15.1 66 13.8 56 12.5 57 11.3 58 10.0 59 8.8 60 22.62 22 67 26.4 50 25.1 51 23.8 52 22.6 53 21.3 54 20.1 55 18.8 66 17.6 57 16.3 68 15.1 60 13.8 61 12.5 62 11.3 63 10.0 64 22.67 22.71 27.6 53 26.4 54 25.1 55 23.8 56 22.6 60 21.3 61 20.1 62 18.8 63 17.6 64 16.3 65 15.1 66 13.8 67 12.5 68 11.3 69 22 71 22.76 28.9 57 27.6 58 26.4 59 25.1 60 23.8 61 22.6 63 21.3 64 20.1 65 18.8 66 17.6 67 16.3 68 15.1 69 13.8 70 12.5 71 22.76 22.80 30.1 61 28.9 62 27.6 63 26.4 64 25.1 65 23.8 66 22.6 67 21.3 68 20.1 70 18.8 71 17.6 72 16.3 73 15.1 74 13.8 75 22.80 22.85 31.4 65 30.1 66 28.9 67 27.6 68 26.4 70 25.1 71 23.8 72 22.6 73 21.3 74 20.1 75 18.8 76 17.6 77 16.3 78 15.1 79 22.85 22 89 32.6 68 31.4 69 30.1 70 28.9 71 27.6 72 26.4 73 25.1 74 23.8 76 22.6 76 21.3 77 20.1 78 18.8 79 17.6 80 16.3 81 22.89 17.4 17.5 17.6 17.7 17.8 17.9 ISO 18.1 18.2 18.3 18.4 18.5 18.6 18.7 Compositions o^ Mixes 413 TABLE 74 (Continued). StanDardi^ing Standardizing cream mix No. 9 testing: f IS-OOVf Fat J 7.50% M. S. N. F. 1 I'l.OO^^; Sugar I .50% Gelatin 40.00 7r T. S. Basis 1000 pounds of mix. Top and bottom lines : Fat tests. Side columns: S. N. F. tests. In eacii snuare: Toi) figure : Pounds butter. Center figure: Pounds water. Bottom figure: Pounds skim-mllk powder. (Blanks indicate none of kind required.) 18 8 18 9 19 19 1 19.2 19 3 19.4 19.5 19.6 19 7 19 8 19.9 20.0 21.11 26 13.2 30 13.8 35 14.2 39 14.7 43 15.1 47 15.6 52 16.1 56 16.5 61 17.0 65 17.5 69 17.9 74 18.4 78.0 18.9 21,11 21.16 26 12.8 30 13.2 35 13.8 39 14.2 43 14.7 47 15.1 52 15.6 56 16.1 61 16.5 65 17.0 69 17.5 74 17.9 7S.0 18.4 21.16 21.20 27 12.3 31 12.8 36 13.2 40 13.8 44 14.2 48 14.7 53 15.1 57 15.6 62 16.1 66 16.5 70 17.0 75 17.5 79 17.9 21,20 21.24 27 11.8 31 12.3 36 12.8 40 13.2 44 13.8 48 14.2 53 14.7 57 15.1 62 15.6 66 16.1 70 16.5 75 17.0 79 17.5 21.24 21 29 28 11.4 32 U.8 37 12.3 41 12.8 45 13.2 49 13.8 54 14.2 58 14.7 63 15.1 67 15.6 71 16.1 76 16.5 80 17.0 21,29 21.33 28 10.9 32 11.4 37 11.8 41 12.3 45 12.8 49 13.2 54 13.8 58 14.2 63 14.7 67 15.1 71 15.6 76 16.1 80 16.5 21,33 21.38 28 10.4 32 10.9 37 11.4 41 11.8 45 12.3 49 12.8 54 13.2 58 13.8 63 14.2 68 14.7 72 15.1 77 15.6 80 16.1 21,38 21.42 29 9.9 33 10.4 38 10.9 42 11.4 46 11.8 50 12.3 55 12.8 59 13.2 64 13.8 68 14.2 72 14.7 77 15.1 81 15.6 21 .42 21.47 29 9.5 33 9.9 38 10.4 42 10.9 46 11.4 50 11.8 55 12.3 59 12.8 64 13.2 69 13.8 73 14.2 77 14.7 81 15.1 21.47 21.51 30 9.0 34 9.5 39 9.9 43 10.4 47 10.9 51 11.4 56 11.8 60 12.3 65 12.8 69 13.2 73 13.8 78 14.2 82 14.7 21.51 21.56 30 8.5 34 9.0 39 9.5 43 9.9 47 10.4 51 10.9 56 11.4 60 11.8 65 12.3 70 12.8 73 13.2 78 13.8 82 14.2 21,56 21.60 30 8.0 34 8.5 39 9.0 43 9.5 47 9.9 51 10.4 56 10.9 60 11.4 65 11.8 70 12.3 74 12.8 79 13.2 83 13.8 21,60 21.64 31 7.6 35 8.0 40 8.5 44 9.0 48 9.5 52 9.9 57 10.4 61 10.9 66 11.4 70 11.8 74 12.3 79 12,8 83 13.2 21,64 21.69 31 7.1 35 7.6 40 8.0 44 8.5 48 9.0 52 9.5 57 9.9 61 10.4 66 10.9 71 11.4 75 11.8 80 12.3 83 12.8 21.69 21.73 32 6.7 36 7.1 41 7.6 45 8.0 49 8.5 53 9.0 58 9.5 62 9.9 67 10.4 71 10.9 75 11.4 80 11.8 84 12.3 21,73 21.78 32 6.2 36 6.7 41 7.1 45 7.6 49 8.0 53 8.5 58 9.0 62 9.5 67 9.9 71 10.4 76 10.9 81 11.4 84 11,8 21 .78 21.82 32 5.7 36 6.2 41 6.7 45 7.1 49 7.6 53 8.0 58 8.5 62 9.0 67 9.5 72 9.9 76 10.4 81 10.9 85 11,4 21.82 21.87 33 5.2 37 5.7 42 6.2 46 6.7 50 7.1 54 7.6 59 8.0 63 8.5 68 9.0 72 9.5 77 9.9 81 10.4 85 10.9 21.87 21.91 33 4.7 37 5.2 42 5.7 46 6.2 50 6.7 54 7.1 59 7.6 63 8.0 68 8.5 73 9.0 77 9.5 82 9.9 85 10,4 21.91 21.96 34 4.2 38 4.7 43 5.2 47 5.7 51 6.2 55 6.7 60 7.1 64 7.6 69 8.0 73 8.5 77 9.0 82 9.5 86 9.9 21.96 22.00 34 3.8 38 4.2 43 4.7 47 5.2 51 5.7 55 6.2 60 6.7 64 7.1 69 7.6 74 8.0 78 8.5 83 9.0 86 9.5 22,00 18.8 18.9 19.0 19.1 19.2 19.3 19.4 19.5 19.6 19.7 19.8 19.9 20.0 414 Ice Cre;am Mixes TABLE 74 (Continued). standardizing table for ice cream mix No. 9 testing: flS. I 7 114. 00% Fat 50% M. S. N. F. 00% Sugar 50% Gelatin 40.00% T. S. l!asi<; 1000 pounds of mix. Top and bottom lines : Fat tests. Si de columns : S. N. F. tests. In eacii sQuare: To)) figure: Pounds butter. Center figure: Pounds water. Bottom figure: Pounds skim-mllk powder. (Blanks Indicate none of kind required.) 18.8 18 9 19.0 19.1 19.2 19.3 19 4 19 5 19 6 19.7 19.8 19 9 20.0 22 04 35 3.3 39 3.8 44 4.2 48 4.7 52 5.2 56 5.7 61 6.2 65 6.7 70 7.1 74 7.6 78 8.0 83 8.5 87 9.0 22,04 22.09 35 2.8 39 3.3 44 3.8 48 4.2 52 4,7 56 5.2 61 5.7 65 6.2 70 6.7 75 7.1 79 7.6 84 8.0 87 8.5 22,09 22 13 36 2.4 40 2.8 45 3.3 49 3.8 53 4.2 57 4.7 62 5.2 66 5.7 71 6.2 75 6.7 79 7.1 84 7.6 88 8.0 22 13 22 18 37 1.9 41 2.4 46 2.8 50 3.3 54 3.8 58 4.2 63 4.7 67 5.2 72 5.7 76 6.2 80 6.7 84 7.1 88 7.6 22 18 22 22 37 1.4 41 1.9 46 2.4 SO 2.8 54 3.3 58 3.8 63 4.2 67 4.7 72 5.2 76 5.7 80 6.2 85 6.7 88 7.1 22,22 22.26 37 .9 42 1.4 46 1.9 51 2.4 55 2.8 59 3.3 64 3.8 68 4.2 73 4.7 77 5.2 80 5.7 85 6.2 89 6.7 22 26 22.31 38 .5 43 .9 47 1.4 51 1.9 55 2.4 59 2.8 64 3.3 68 3.8 73 4.2 77 4.7 81 5.2 86 5.7 89 6.2 22,31 22.36 38 43 .5 47 .9 51 1.4 55 1.9 60 2.4 65 2.8 68 3.3 74 3.8 78 4.2 81 4.7 86 5.2 89 5.7 22 36 22.40 1.3 43 44 48 .5 52 .9 56 1.4 60 1.9 65 2.4 69 2.8 75 3.3 78 3.8 81 4.2 87 4.7 90 5.2 22,40 22.44 2.5 46 1.3 47 48 52 .5 56 .9 61 1.4 66 1.9 69 2.4 75 2.8 79 3.3 82 3.8 87 4.2 90 4.7 22,44 22.49 3.8 49 2.5 50 1.3 51 52 57 .5 61 .9 66 1.4 70 1.9 76 2.4 79 2.8 82 3.3 88 3.8 91 4.2 22 49 22.53 5.0 53 3.8 54 2.5 55 1.3 56 57 62 .5 67 .9 70 1.4 76 1.9 80 2.4 83 2.8 88 3.3 91 3.8 22,53 22.58 6.3 57 5.0 58 3.8 59 2.5 60 1.3 61 62 67 .5 71 .9 77 1.4 80 1.9 83 2.4 89 2.8 92 3.3 22.58 22.62 7.5 61 6.3 62 5.0 63 3.8 64 2.5 65 1.3 66 67 72 .5 77 .9 80 1.4 84 1.9 89 2.4 92 2.8 22.62 22.67 8.8 65 7.5 66 6.3 67 5.0 68 3.8 69 2.5 70 1.3 71 72 7S .5 81 .9 84 1.4 90 1.9 93 2,4 22,67 22.71 10.0 70 8.8 71 7.5 72 6.3 73 5.0 74 3.8 75 2.5 76 1.3 77 78 81 .5 85 .9 90 1.4 93 1,9 22,71 22.76 11.3 72 10.0 73 8.8 74 7.5 75 6.3 76 5.0 77 3.8 78 2.5 79 1.3 80 81 85 .5 91 .9 94 1,4 22,76 22 80 12.5 76 11.3 77 10.0 78 8.8 79 7.5 80 6.3 81 5.0 82 3.8 83 2.5 84 1.3 85 86 91 .5 94 ,9 22 80 22 85 13.8 80 12.5 81 11.3 82 10.0 83 8.8 84 7.5 85 6.3 86 5.0 87 3.8 88 2.5 89 1.3 90 91 95 ,5 22,85 22 89 15.1 83 13.8 84 12.5 85 11.3 86 10.0 87 8.8 88 7.5 89 6.3 90 5.0 91 3.8 92 2.5 93 1.3 94 95 22,89 18.8 18 9 19.0 19.1 19 2 19.3 19.4 19.5 19 6 19.7 19.8 19.9 20.0 Compositions of Mixes 415 TABLES FOR COMPOUNDING, UPON 1000 POUND BASIS, ICE CREAM MIXES OF VARIOUS TESTS AND FROM VARIOUS RAW PRODUCTS. Tables 75 to 84 inclusive, immediately following give the pounds of various commonly available raw products necessary to mix together, in order to produce ice cream mixes of the compositions indicated. Tiie tables are all made upon the 1000 pound basis. The proportions will of course hold for any quan- tity desired, either greater or smaller than 1000 pounds. The accuracy of the tests of the various mixes is limited to the accuracy in the composition of the products used, as compared with the composition named in the tables. This method can be depended upon to give only approximate results. It is not recom- mended when accuracy is desired, nor when the aim is to make a uniformly standardized product. The heading over each table enumerates the products used. The products used are also given upon the left hand side of the table, together with the composition of the same. The composi- tion of the nine different mixes giving the fat, M. S. N. F., sugar, gelatin and total solids is found in the upper half of the table. The pounds of the various products necessary to use to make 1000 pounds of mix, are given in the lower half of the table. The various combinations of products used in the several tables are as follows : Table 75. Mixes of nine compositions ; made from 18 per cent cream ; evaporated milk testing 8.00 per cent fat and 26.15 per cent total solids ; whole milk ; sugar ; gelatin and water. Table 76. Cream ; plain 8 per cent condensed whole milk ; whole milk; sugar and gelatin. Butter necessary in two compo- sitions of mix. Table 77. Cream ; plain 9 per cent condensed whole milk .- whole milk ; sugar and gelatin. Butter necessary in two compo- sitions of mix. Table 78. Cream ; plain condensed skim-milk ; whole milk ; sugar and gelatin. Table 79. Skim-milk powder; butter; sugar; gelatin and water. 4l6 icE Crkam Mixes Table 80. Sweetened condensed whole milk; cream; skim- milk powder ; butter ; whole milk ; sugar and gelatin. Table 81. Sweetened condensed skim-milk ; cream ; butter ; whole milk ; sugar and gelatin. Table 82. Skim-milk powder; whole milk; butter; sugar and gelatin. Table 83. Sweetened condensed skim-milk ; cream ; sugar ; gelatin and water. Table 84. Sweetened condensed skim-milk ; butter ; sugar ; gelatin and water. METHOD OF CALCULATION USED IN DERIVING INGREDIENT FORMULAS. J. A. Cross devised a unique method of calculation that was applied in solving all the problems included in Tables 75 to 81 inclusive. This method can be applied to any combination of substances that it may be desired to use in making up ice cream mix. The example used to illustrate the method is taken from Table 75 and is as follows : — Example: Wanted to make 1000 pounds of ice cream mix testing 8.00 per cent fat; 11.50 per cent M. S. N. F. ; 13.00 per cent sugar, and .50 per cent water free gelatin. The materials available are cream testing 18.00 per cent fat, and 25.59 per cent T. S. ; evaporated milk testing 8.00 per cent fat, and 26.15 per cent T. S. ; whole milk testing 3.50 per cent fat and 12.00 per cent T. S., sugar testing 100 per cent T. S. ; and gelatin testing 87.00 per cent T. S. Solution: Each 1000 pounds of mix must contain 130 pounds of sugar and 5 pounds of gelatin. Therefore 1000 — (130-)-5): 865 pounds of milk products. The 865 pounds of milk products must contain 80 pounds of fat and 115.7 pounds of M. S. N .F. (The extra .7 pounds is added to make up for the water contained in the gelatin used. 5 — (5X-87)=r.65. 80-^865^:9.25, per cent fat required in mixture of milk products. Compositions of Mixes 417 115.7-^865=13.39, per cent M. S. N. F. in mixture of milk products. The tests of the cream, evaporated milk and whole milk respectively are plotted upon the basis of their fat and S. N. F. contents, and lines are drawn from the one to the other to form a triangle. The test of the mixture required is then plotted within the triangle. The other lines are then drawn, all being as illustrated under Fig. 89. Accurate measurements are made of each full line that intersects the point of the mixture inside of the triangle, and in turn of the short line which extends from the central point to one of the sides of the triangle. The larger the triangle the more accurate these measurements will be, and when many determinations of this kind require to be made, a drawing board and T square can be used to advantage. By simple ratio the proportion of each ingredient required is calculated as follows : — A^D 1.046 cm. 1.046 A^A 4.494 cm. 4.494 B^D .7819 cm. .7819 B^B 3.246 cm. 3.246 C^D 1.7213 cm. 1.7213 C^C 3.273 cm. 3.273 1000 lbs. of mix require of 865=201.3 pounds cream re- quired. of 865=208.8 pounds milk re- quired. of 865=454.9 pounds evapo- rated milk re- quired. 130.0 pounds sugar 5.0 pounds gelatin. Total, 1000.0 pounds mix. „ I 7.994 per cent fat. \ 32.99 per cent T. S. 418 icE Cre;am Mixes O '" i ■" (\J ^ JZ ^- a^tl'l^l^^L'^ELli.^Z^ L _ 5^ it $''>. m ^ S. •O _ N^^ X \ ^s. ^^ s $ \ jl- _ . _ ^s, \ 1— S ^v ^3^ 1 ^ L S • -t^ \f r\ ^A \^ ^ zt •j- — TTtTT'-KklHn T m^ *n Tr t" ' n"r r T it M" Xs» J Yv'"*'^^ S ^'^ -t '--S^?" it ___ :±_ J \^ ,<\ yz _"+-!- z ^^^'^ ^ a^j3usr]Ztci3E^£iiE: ^ J - -•'^^ ^ T / A^ E5l lo _ . ."^ ^^^ z: "J / ?" - J-^^ -.. 2 .- ^ * ^_' |e2^5^iE3LL^3tE^S^a3iI!- Mil ,__ _ O 5 lO 15 20 °7o S.N.F. Fig" 89. Diagram Showing* Graphic Method of Standardization. In the above diagram point A, representing cream testing 18 per cent fat and 7.59 per cent 8. N. F., is plotted as indicated. Point B, representing whole milk testing 3.5 per cent fat and 8.5 per cent S. N. F., and point C, represent- ing evaporated milk, testing 8 per cent fat and 18.15 per cent S. N. F., are plotted in the same way. These three points are then connected to form the triangle ABC. Point D represents the mixture desired, testing 9.35 per cent fat and 13.39 per cent S. N. F. l>ines are then drawn tlirough AD, BD and CD to the point where they intersect the side of the triangle. The ratio of A, D to A, A times 865 represents the pounds of cream required. The ratio of B,D to B,B times 865 represents the pounds of whole milk required and the proportion of C,D to C,C times 865 represents the pounds of evaporated milk required. Adding these three amounts, and the sugar and gelatin necesary, the sum will be 1,000 pounds. Mixes of Nine Compositions ,419 bO < S ^ 1 fie o g S g m T3 C c o c O o I> O fl C 1-1 Tf c lO O ^ 'M O) "+ CC 3 CC o~ CO 't o Si 1— o: O iC (M r-H ^5 Ph Ph 1-M ■+J fi c o "O g C g Tf t> 02 c c o CC ^o, oc 'Tt- ir: § OC 2 § iC g ^ <— cc O IC o a; PL. " ^ fi c 0) g o g g g t^ CI c c o u: o c X C3- 05 c iC o ^c o ^ IC X t-- Q ^ o u, X fc O cc CC ^H o 0) Oh Ph '^ ^ fi C o (^ c e CO Tt cc CO c c o QJ I— . lO o IC £ •^ o C o- 1— Tf c lo ^ c f-H cc •^ ^ cc cc CO cc ^ Lh ,-H cc o Ol Tf ^ Ph Ph " ^ S c e (^ cr e tZ3 GC b- lO c c o <» iH e ^ ir. ^ o: Q fi c O* »c c Lf: o oc iM ot "+ 3 Cv CO cc u cc O c^ If: (^ 0) (1h PM '"^ 4^ c c o ^ C e 73 -a liT cc ■M c c: o 0) ?= •o (^ «c £ CJ u fi c b- t^ c iC o GC M cc -* 3 r^ tr. CO cc o Lh i-H I— cc o tr. r— o PL, Ph " -f^ r^S o g c g a: cc a- 00 c c o o fi •^ 00 c If: o oc *-H cc cc ^ c ir. o cc ^ i—H T-H oc O c^ 't 'M *— o PL| Plh " ^ fi c- ir. e f^ ^'5 ir ^ o c ir cc Ol 1^ t- H'i c^ C- e oc '/ a fe Ph "s ^ _c ^^ cr If: o c k^ ^S iC •o cc d oi a; c b D V t-- GT 00 §■ C^ 0. C h -»j _c fi c (3 o ' "So c c lO OS X oc OC CO "a pL. "o (C 1$ O ■ fi ■^1 P IS. o Ph 6 a. "S s t1 bl 3 03 o u U w CC o H 420 Ice Cream Mixes o CO «« pa O) <1 O o H - o fl o u o Per Cent 18.00 § t- ^ c Pounds 730 • CO .—1 u: If: 1 00 Per Cent 16.00 o o o ° 8 GO CO Pounds 711.1 d .—1 •o o o o i^ Per Cent 12.00 o o o I— 1 ° CO Pounds 569.8 d 00 § lO i o Per Cent 12.00 o 00 •n* s CO Pounds 588. o CO 3 LO o lO Per Cent 10.00 o d o o ° 8 CO Pounds 415.6 o d d C^l 01 d iC i Tt< Per Cent 9.00 o O O CO g CO Pounds 367.9 00 o CM CO CO C^l d CO iC o CO Per Cent 8.50 8 o o CO s CO Pounds 285.2 GO Oi o CM 00 C^l d CO »c o 8 Ol Per Cent 8.00 O o o CO s 8 CO Pounds 242.3 CM CO Ol s lO o - Per Cent 8.00 o o o CO o CO CO Pounds 260.5 o s 00 CO CO § lO o X "o 6 fe ^ aj ^ s ) T. S. 25.59 8 CO CO 8 CM 8 d o 8 00 GO 03 M. S. N. F. 7.59 8 00 iC 0) bC o ki 03 CO C '■^ s 1 o l^s o 00 o CO CO 00 OJ S ^ i t c id o: b D c "o! C 1 C £ c c c tK 2 C ^ !- ^^ r H c S2 r Mixes of Nine Compositions 421 o N JS 1-4 ^ < x) H S a a> -o fl Ol Per Cent 18.00 o 14.00 .50 ^ fa 738.4 67.1 § 5.0 19.5 1000 Per Cent 16.00 o o o c 02 3 -c CO o 1 1 r. lO O lO c ^ S ■ h^ f^ 00 l^ Tf^ 0( ' fa CD Ol 00 lO § "" CO ^ tc 1 . -t-O o c :> c 3 C 3 -a Tt< 1 r^ a: o c 3 o Pei Cen 12.0 to c J >r 5 C 5 c ■ o t^ 3 Cft iM (M o If 3 o Ol -^ M c£ 5 o CD -rfl ^ ¥ ^-1 ^ C = fa lO — < tc ^ +^S o c 5 C 3 C 3 -0 0( D CD CO o c 3 o S", c ^ lO c 3 ir 5 C 5 G o CO ^ s • 3 ^ lO o ir 3 o ^U2 00 '^l ir ? O o( D O t^ ^ ^ H C"- ' fa If 3 CO '. ^■^S o c > c > c 5 'O -^ ■< Ol "* o c 3 o ^^ co lO c 3 »r ■< c LO r?' 33 ■ 3 o 3 lO o o ir 3 o ^u2 o "i IC 3 O c 3 03 iCi •^ ,_) "" c ' fa -^ Ol (B , -t-^o o c > C 5 (^ > -o c£ 3 ^ > c Q -* fs^o C 3 O Tt< d If 3 ^ »— 1 c ^ o (> ) ^ O CO t— 1 '"' *" 0- fa c 3 C^ CO ^ CO . +^o o c C ^ TJ a S Tt< t> o c > ^ ^1 c ^ o ^ IT C Q CO ^(3- H «: J «o d d ir > ^ Ol c<- 'J o fa i^ CD Ol (M d IT ^ Oh^QO C^l c^ ■^ o c^ > 00 -* CO f— 1 ^ *" CO fa (> c^ CO cc L. -*^'=> o ^ C c -o o ^1 c o lO ^ «7 c: C Q i-H ^''^ 5 ■ 3 c^ l^ lO d ir ^ f^u^c 1.-H cc CO O fa ir CO t- CO 1-H ^ ■" CO (N co a Q o ^ X M kO'^ o o iC (^ ^ fa H &-^ CO c^ d l> -* 2 o CO o OC OC "o ^ ^C ~ 6 czf 1 a: Mfa' ^«f 8 g IC 03 1 fa 1 ^' _K 0. H S'^ Ol 00 - - o o 03 fa ^ OC o 03 CO CO 00 - -^ -§1 M a 6-s si 1 'o o; Lh « d a. o3 ^ ^ ^ W) "S -1-2 3 o 1 'a C fa c» _^ CQ H CO K <4-« C/3 C>TS "o O C- CO 03 c -73 "C S 3 is O a QJ C s S"*- o 03 C ; p !^ ^ 1 422 Ice Cream Mixes O c4 .9 rfi a" 4) a O: Per Cent 18.00 O Tti S 8 d -a c O Oh (M 00 CO 00 O CO d o o OO «1° OhqcO o '*' O o o 00 CO -a c o CO CO CO § lO i t^ • 05 8 o 8 CO O CD 00 00 UO § lO i O o 00 ^' ° CO ■73 C O Oh CO UO ■00 d d lO i iC PhqO o d o o g CO 03 c 3 O d CO (M d 5< d lO o ■* o CO o o o CO 72 3 o CO d GO § •o o CO (M CO o CO 02 t3 c 3 O CO 00 00 CO d CO >Ci i (M 8 CO o 8 CO CO c o Oh CO CO CO CO CO 00 CO CO o d CO lO i - ^ GO IIhq.OO ° 8 CO s CO CO 03 T3 s o 00 (M d CO . >o i 6 o: b 1 02 o CO (M 8 00 3 o o O O 00 bO 03 1 'i 1 o ri fe ^1 ° CO o « bl 3 ) c a t: c a £ : o c 3 t- £ I'd f 4 5t3 Mixe;s of Nine Compositions m o M 1 , +i o o o o -a CO o o o t^ o 5r^ c lO o lO o c Ol ^''^ £ p d «o o lO c^ g Phq oc l^ ■^ d o t^ Tt< CD •* ?; lO 2 , +j c o o o o CO 73 l^ o o o CO o ir, c c lO o lO o c 00 ^ £ 3 d (N o lO CO (^ (^o i;c t^ •* 00 o t^ Ol ■^ 00 o >— I cc PL. '"' >o 2 O! , *i o o o o T3 00 CO o o Ol o ^, c lO o lO o t^ rP £ s 00 CO o lO o; § f^O c< 03 ■* d o a> •* -* .— ( CO Cm '"' ^ s 2 03 . -»j o o (^ -o (N »o o .o CO o ^, c iCi •o Q q <© S' £ 3 00 CO o lO CO d f^o c- 00 ^ »o Q 00 ■* ^ (M CO CLi ^ CO 2 CO jj o o Q -o o (M o o 00 o !r c lO lO Q c 'O -P q3 3 d 05 o »o lO ^u c d ■^ lO o Oh ^ CM CO ^^ ^ CO 2 03 . +^ o o Q -0 o o o o ■i cc Tf o Plh CO 02 CO ""• CO CD 2 03 j_, o c o -o 05 c c o o 5r; c »o iC Q c 1-H «*^ S 3 c2 1-H iC c iC oc o f^o OC - IX CO CO c^ O: CO 3 § (_, c ^ X cc CQ iC ^ 's fc ^ h ^ t- ^^ 05 oc QC "o ^ o CO c 6 aj t- "S "^ ODfo c ^ s D V ->J ^ a: 0. o s';^' " ~ +3 ^ i ^ OQ PL4 oc bO oc 03 c V 0) • - a) D. t. _c OQ "a . al 0. 1- c: b in c "5 o CO Q o<-. 73 * ■^ Ot: 3 *o a; ! J CZ3 C t) c = ■?•- :: .2 o"^ ' § c 3 '+S c c 5 O > 'So c3 t - U.I o «« J a s- I'll s o cs <: t> o /^ 1 424 IcK Cream Mixes ^ .2 PQ -a ^ ,d (^ h-) M g s rH a a ^ U) CS 0) fe o 4-1 n a~ e8 b« u Mixes of Nine Compositions 425 bfl 3 Xfi -o .2 m ^ C CO o O) O Per cent 18.00 o CO o d 03 c 3 o d CO o CI d d i o o o fO o o o 00 CO o 00 00 CO d lO o o 02 CO o d CO CO -o 3 3 o Oh CO CO CO CO CO 00 00 »o o CO o t>0 CO o 8 CO 02 3 3 o CO o lO CO 3 3 O Oh o 05 CO CO CO CO d § CO 0. goo o o CO o lO CO to 3 3 O lO d o CO CO 03 CO CO lO o C<1 (U c o •^ O GO o o o CO o o o CO CO -o 3 3 O Oh 00 00 CO CO d CO 00 iC d 8 - S3 c8 ^ Soo o CO o CO CO 03 C o CD 2 00 CO d 00 CO CD CO d i d c m ^ o >o 00 (M g CC »o 00 .1 03 bC m o "c3 GO CO 00 lO CO J (B CO 21 o ir; 3 s O s 3 m or3 3 m O "3 o ■« a 'i.s a S o O a -i n c4 3 CO © § 3 -4 a, ~ 00 V u I 2 w o p t= '2 s _ H GO (U e o CO 1 1 , -1-3 (3 o O o o -o 05 in 1 CO »o lO o Oi . . ^ d d 06 d d 00 t>. ■^ d o Pi CO 00 -* 1—1 ^ CO I-H '"' 2 01 -, ^ o ^ o ^ -a r^ CO 1" (^ lO ^ iC ^ c 00 . 3 o d Th -* d iC d CO l> "^ 00 ti CO Tt< 1—1 CO CO '"' '"' tc Q o (^ o o TJ 1— 1 CO CO h c ^ «o ^ lO o c t^ o d •i -* d 10 d (M 05 Tt< CD CO 1-H '^ >— 1 CO t^ '"' '"' M -^ Q o o o ^ -o CO CO T—H .^s o lO o iCi o c o "* d ■* d 10 Phu C-l 00 Tt< CO o c^i r^ ^ -H § X -4-^ o o ^ o (^ "O 00 CO CO £| o lO ^ lO o c iC lO d d d lO d d '* lO o ■* CO '* '"' CO t^ '"' 2 (» ■*^ 8 o o o o -c ^ t^ 05 bi c to o lO o c ■* d c^ CO d lO d Oi ,-H CO -* o »C CO ^^ CO ^ CO t^ '^ OJ . -f^ o ^ (^ o -o t^ ■* 05 i", c o Q ^ o o c CO ^ S 'O d CO d Id d ^u 00 OJ CO -r o Plh CO CO i> CO '^ ■"^ CO t^ '"' cc . +^ (^ o o o o -o 1-H CO CO '-' c lO o lO (M ^"^ S O Ph d -t^' ^ iC f^u 00 (M c<; 'f CO CO CD CO ^ '"' CO t^ ^^ 2 CO .4L;> o ^ o o ■a o 1-H CO q b- c iO ^ LO ^ c f-H ,^''' § '^ d "^ lo (^o 00 r-H CO CO o Ph tC '^ CD CO ^ CO r^ ^ Q ^ X m 02 &^S 10 fc -o H ->) Ttl t^ •" -— ' Ol 1-H 00 00 *© ^ _c o %. __ o 6 02 o: K 03 M^' 6«° 10 »c ^ % c o §^ 06 J-, -^ ^5 10 xn o3 (U fe CO CO bC oc 83 ■4^ c 0) ^ c i1 a b. c tm* E o '0 0: "r '« m X :5 =^ tt fa " I CO to 't; -S*^ °7 "o ni O CO a c r '■+3 c a 'S c3 t. D, s- 2 S o 1 eS P a ) U z; 1 Mixes of Six Compositions 427 o ■^ hj o 8 s d Tti ° o o CD CO 3 o o s 1— 1 CO CO d o 00 d i "O ^1 8 (M o 00 8 o o o d CO 02 s 3 o 00 00 CO CO 05 00 o CO i •* O O d o o o o o CO 03 -a c o 00 CO 00 CO o t^ o CO l| 8 05 o 8 CO ° o o CO CO -a c o o 00 CO d o i .—1 IM II 00 o o o o CO o CO 03 c 3 o CO 00 CO o CM o - S3C o o 00 o CO o CO CO CO 3 o CO CO CO CO o CM i 'a 6 "A 3 "a -2 m o ai H &*? d "5 1 8 00 ^ 05 £^ o 00 : a lU o ;-i s. m 0) 1 O a o O CO c : i o >-• OS '-(3 o "3 o 'of cc ■- CO P "St s >■ J3 < o < r 428 Ice Cream Mixes TABLE 84. Mixes of Thiee Compositions. Made from Sweetened Condensed Skim-Milk, Butter, Sugar, Gelatin and Water. 1000 lb. Basis. No. of Mix 1 2 3 Fat Per Cent 12.00 Per Cent 16.00 Per Cent 18.00 Composition of Mixes in Percentage.? M. S. N. F 8.50 7.50 7.50 Sugar 14.00 14.00 14.00 Gelatin .50 .50 .50 T. S 35.00 38.00 40.00 Sweet Condensed.. . Skim-milk. . . Fat M.S.N.F. T. S. Pounds Pounds Pounds Name and tests of products with pounds of each required % .50 % 27.50 % 70.00 303.5 264.6 263.6 Butter 83.00 1.50 84.5 142.8 191.4 215,0 Su^ar 100. 12.5 28.9 29.3 Gelatin 87. 5.0 5.0 5.0 Water 536.2 510.1 487.1 Total 1000 1000 1000 TABLE FOR COMPOUNDING ICE CREAM MIXES IN VACUUM PAN. Tables 85 to 87 inclusive each in turn give the pounds of three different combinations of raw materials, necessary to pro- duce nine different compositions of ice cream mix. These are all calculated upon basis that will yield 1,000 pounds of finished prod- uct, when condensed to the concentration desired; in the vacuum pan, using the Mojonnier method. The proportions given will apply to any size of batch of finished product that may be wanted either larger or smaller than 1,000 pounds. The arrangement of the tables is similar to that followed in the tables just preceding. The combination of products used was as follows : Table 85, Whole milk, butter, sugar and gelatin. Table 86, Whole milk, butter, sugar and gelatin. Table 87, Skim-milk, butter, su^ar and gelatin. Mixes of Nine; Compositions 429 "3 o O eu •o T) a ID ei ja m u a en • fh M t^ 9 09 ^ kl ■4-> i-i 3 1 :^ fH -O Is a (^ n 6 p a> 3 TJ wt s > 03 |1 8 1-H o Tf o d CO '73 c o o d o O CO d 1 GO ^1 8 o o o o CO CO G 3 o Ph o 00 d O 1— 1 i t~- ll 8 o 05 "* o 8 d CO g o Ph o 8' CO 00 o d o CO o CO i to CO CO ^ ^1 c o LO o »o o a o 00 ^"^ S lO c^ o lO CO CO o P^O CO l:^ •* 00 6 Ph CO lO ■* CO CO *"* ^ CO . 00 '"' ^ ^ ^ O! ,tj. o o ^ o o -O O 00 o t^ lO o Q 5r; c o »o o lO o c o t^ n"^ « m d d >o CO CO o ^o C^l CJ Tf CD o p^ t^ 05 -^ t-H 1-H 1-H ^ ^ CO o CO CO 03 , -tJ ^ o ^ o O -a o (M o t^ Oi 03 ^ Sr! c o lO ^ lO O c o CO n^ £ 3 O Ph d 00 d lO CO CO o f^o oi 00 "^i iO CO Ol Tt< o o tM i-H '"' CO Oi (M (M o: , -M o o o o o TS o 03 o t^ CD CO o S"i c o »o o ■o o o lO ^"^ S 3 CO (>i d lO -* -* ^ f^o d d Tfi i2 o Ph Oi CO ■* O o T-H CO Til •* 1-H ~^ o ~^ o o 02 o ^_i o I--. 00 00 ^ ^5 c o •o o lO o o Tt< f^^cS lO lO d lO »C lO ^ oi 1— H CO '^ O Ph TfH CO 03 Oi I-H '"' '"' CO CO -^ rt< . -fj O o Q o o 02 o CO o t>. O O J_, fe c lO o o lO o 3 O Ph • ^ CO c^ CO d LO Tt< Tfi o 00 (M CO Tt^ r^ CO CO T** "* r— 1 CO CO lO »o . •*i Q o Q o (-, 02 o •* o i--. __l ^_i J-, m S o lO o >o o g o iM ^c5 (M t^ o >o •o »o (^ 00 (N c<: ^ O Pk CO (M CO 05 10 Oi lO '"^ _^ Q o o o (-, 03 o o o t^ t^ !>. o 5n c o lO o iC o rH o *-H «" S lO CO o o CO CO o P^U X m c^ CO CO o° i ^ CO CO 00 00 Ph 1-H o o ~^ o 02 03 C/2 &5 t^ lO ^ o V X i^ ^ H (N •* o t^ 'a ^ _e 3 M 00 o 00 o cc o: K "^ cofs; O o 6 en ^ cr. C o ^^ £5 00 o o CO &5 o o 0) fe ■* CO 00 03 •♦^ a 0) o -lli ■i3 "a t. r^ O s. a _c a -a ) 02 3 !- o; b 'a z 5 OJ : 'S 'a ^ m a 3 C ) ^ ^2 i E 03 't: *-¥^ -tJ C 5-0 O 03 « 1 ^ C o C i'3 -o : 3 & '•♦* C? 5 S^ 'S 03 f > ^H a x^ ;§ s a*: o e3 C 5 3 • t-t W 13 U4 -M 3 m CQ ,a i-J .i<) o o s »H a IS 2 "3 w >^ o 05 ^ Oi Per Cent 18.00 Tti S d 03 c o o 00 So o to o »o 00 00 »H 00 "-co O o o S O o CO 02 c 3 o o 00 GO d C5 o d »o 00 »o 1 t^ o to ^ O lO CO CO 03 c O o to o d lO 00 CO 00 CO i o o lO •^ o to 8 lO CO c 3 O o CO CO o d O CO O-l o CO o o o IC III o lO o o o •o to CO CO 3 O (1^ o 00 1-H o d CO lO CO —1 Tf ° ro § o o CO 03 c o Oh o • o lO o o d CO lO CO LO CO lO i CO flH^OO (M CO o lO 8 CO OJ -a a o o CO CO d 05 o o CO ■o d "O C5 i iM CO o o o CO 03 o .o •*' o o ■ CO o o to CO CO CO CD o - o CO o •o CO CO 03 3 O Oh o o CO o d CO lO d >o lO o 8 6 c b ) IH "o o 8 fe5d lO ^- 00 • o 00 o 02 fe 00 ^'^oo o lO (U iaC o3 "c „.....». 1 I, j N. 1 1... «.. ».. "i.if.r' "i.lif "ii-S" "ijja 1 'iisf -— — - - - ' — - ^...s - -- -- : 'IZ'Il - ■ - ":z: - :zz — Tig. 113. Blank for Recordinif Overrun Beadingfs, Sixth operation : If aiming for 100 per cent overrun and the test shoAvs between 95 and 100 per cent, turn ofif: the brine and draw the freezer. Where the overrun is more than 110 per cent, the product is usually unsatisfactory, and the overrun should be brought back to the point desired, by momentarily turning on the brine. If the test shows less than 95 per cent turn off the brine and continue whipping until the desired percentage of overrun is obtained. The frozen ice cream should be sufficiently viscous to retain all of its overrun during the hardening process. Seventh operation: At this i)oint draw the ice cream into the cans, and record the percentage of overrun in the proper i Overrun in Fruit Ice; Cream 475 column of the freezing room record sheet, illustrated under Fig 113. Ice cream of ideal texture will have the appearance of taify when it is frozen, and ready to be drawn from the freezer. If of the proper texture it will stand considerable handling, without suffering an^^ bad effects. The ice cream should be drawn from the freezer as rapidly as possible, inasmuch as the overrun keeps changing upon the part that remains in the freezer while the balance is being drawn out. The change may occur in both directions. If the critical phase has not been reached, the overrun will increase, making the last portion of higher overrun than the first portion. If the criti- cal phase has been passed, the overrun Avill decrease, making the last portion of lower overrun than the first portion. If the ice cream is drawn rapidly the danger from these fluctuations can be great!}' reduced. Proper manipulation of the brine valve may frequently assist in preventing the above changes. It is important to draw off the ice cream as rapidly as possible when the proper overrun is reached, so that the overrun does not increase during the time of drawing off. A helper may be used to advantage at this time to bring in empty cans, and take away filled cans. HOW TO DETERMINE OVERRUN IN ICE CREAM CONTAINING CRUSHED FRUITS. It is recommended that a different standard be set for ice cream containing crushed fruit, than for the plain varieties. For example if the standard for plain variety is 100 per cent, a stand- ard of 90 per cent in the case of ice cream containing crushed fruit will yield a very satisfactory product. REFERENCES. 1 Washburn, R. M. "Principles of Ice Cream Making," Vermont Station BuUetin No. 155. - Baer, A. C. "Ice Cream Making," Wisconsin Station BuUetin No. 262. 3 Mortensen, M. Factors which influence the yield and consistency oJ Ice Cream. Iowa Station Bulletin No. 180. * Hammer, B. M. and Johnson, A. R. The Specific Heat of Milk and Milk Derivatives. Iowa Station, Research Bulletin No. 14. 5 Cutler, Thos. H. Ice Cream Trade Journal, 1920. Morse, James B. Homogenizing the entire mix. Ice Cream Trade Journal, 1920. ' Hanna, E. C. The Viscolizer is an important factor in the ice cream industry. Ice Cream Review, 1921. » Hall, Thos. Microscopic and Thermal Analysis of Ice Cream, P. 71, Ice Cream Trade Journal, December, 1921. CHAPTER XVI MICROSCOPICAL AND BACTERIOLOGICAL TESTS OF DAIRY PRODUCTS WITH DIRECTIONS FOR THE CARE AND USE OF CULTURES THE USE OF THE MICROSCOPE IN THE DAIRY INDUSTRY. Th^ microscope is used to great advantage in dairy control work. It is indispensable in identifying bacteria, and it fre quently affords a rapid means of determining the physical con- dition of milk substances that would require a large amount of time and labor to determine by other methods, or would be al- together impossible. The quality of milk is fixed to a large de- gree by the number and kind of bacteria that it contains. Also the physical condition of some of the constituents of dairy prod- ucts influences the process of manufacture, the treatment they must receive, and their market value. The successful use of the microscope in determining these factors does not always require the services of a highly trained individual. Any resourceful, intelligent young man or woman of limited training can determine the number of bacteria in milk, the size of fat globules, and the presence of milk sugar crystals, when provided with necessary equipment, some instructions at the beginning, and the directions given in this chapter. These brief directions should enable any skillful person to use the microscope successfully in the simpler operations. If the instrument is to be used to a large degree it Avould be advis- able for the operator to obtain special training, and to consult books devoted especially to the subject. Care: Some knowledge of the microscope on the part of the operator is necessary in order to work to advantage, and to keep the instrument in good condition. Like all instruments of pre- cision, it should be handled Avith reasonable care, and kept free • [476] The Microscope: 477 of dust and all corroding elements. When the instrument is not in use it should be kept in a case, and stored in a reasonably dry place. If frequent use makes it impractical to return the in- strument to its case, a suitable cover should be placed over it when not in use to protect it from dust. The frequent removal of dust from its polished surfaces is liable to scratch them, and if the dust gets into the bearings and close fittings, they will work harder and cause unnecessary wear. ■Rack & BniCN CoARse AoJuaTweNT NosEPiecE Objectives Grasuatcc Short SLic t — — flevOLVING Stage floJUSTABLE Spring Finger CoNDENSEI^ MoUNTmS Drop •5wing Arm—" Lower Iris Diaphragm -- roR OeuftuE Light. Stage CkNTCRiNG •Screw.s'^ Mirror lVliRRO*\ roR«>-. MiRftOR Bar T?ACK & PmiON £yTTOH Concentric Altutt- ng Buttons Grabuated Long L5lh>e Horseshoe .— -Bas e Tig, 114. Microscope with ITames of Various Farts. Courtesy Spencer Lens Company. Do not leave the microscope exposed to direct sunlight for a long time. Avoid rough handling of the instrument and when it must be removed, grasp the pillar below the stage. The oculars 478 Bacteriologicai, Tests and Cultures and objectives should never be allowed to fall. Do not allow acids, alkalies, alcohol, turpentine or chloroform to come in con- tact with any part of the microscope, as they will dissolve the lacquer. For finger marks or material on the surface, that can- not be removed with a soft cloth or clean chamois skin, use a damp cloth and rub gently. In exceptional cases, it may be necessary to apply a little xylol, ether or chloroform to the sub- stance, and then rub it off gently so as not to remove the lacquer. Stage: This is the part that supports the slide while a speci- men is under examination. Should the stage become soiled with anything which water will not remove, apply a little xylol, or chloroform and rub it off with a clean cloth. If the stage turns to a dull gray color, it may be restored to its original black by rubbing a little of some heavy oil on it. When the black color has been restored wipe the stage free from oil. If any substance falls on the stage it should be removed immediately. Inclination Joint: This joint, which permits the body of the microscope to be inclined at anj^ desired angle, sometimes wears so loose that it will not support the body properly. The joint may be corrected by tightening the nuts on the end of the in- clination axis using a heavy screw driver if the nut is slotted, or a "spanner" if the nut is provided with two small holes. A round nosed pliers may sometimes serve to turn the nut. Do not mar the nut with the tools. The axis pin is slightly conical on most modern instruments. This makes it possible to tighten the joint by turning the nut on the end that will draw the pin tighter into its bearing.* The nut on the other end may first have to be slightly loosened, then tightened after the cone is drawn in to give the necessary friction. Coarse Adjustment: The bearing of this adjustment should work so smoothly that the highest power may be easily focused with it. But it should hold the body of the microscope securely in place. If any foreign matter interferes with the working of the bearings rub a little xylol or chloroform on them to remove it. Oil the bearing with parafin oil or ' ' watch ' ' oil after they are thoroughly cleaned. Keep the teeth of the rack free from for- eign substance at all times and use judgment in making necessary repairs to worn parts. Adjustments 479 Fine Adjustment : This is much more delicate then the coarse adjustment, and of limited range. The micrometer head is lo- cated at the top of the arm in one type while in the other there are two micrometer heads, one on either side of the arm. The micrometer head should turn easily and smoothly, yet fit snugly, and hold the body of the microscope at all times from slipping down with danger of damaging the objective lens and the object. The range of the fine adjustment has been reached when no change of focus occurs while the micrometer head is being turned. The micrometer head should then be turned in the opposite direction until nearly the middle of the range is reached. If the thread is turned ofi: its bearing, as may happen with some of the older forms of microscopes, take great care to start it on correctly, and not cut the thread. If there appears to be any unusual friction do not force it. When anything ex- ceptional needs repairing it is better to have it done by an ex- perienced mechanic, or by the maker. If the fine adjustment is not so constructed that it ceases to work when the objective rests on the cover glass, great care must be exercised in focusing so as not to crush the specimen or damage the lens. Draw Tube. This should fit snugly, work easily and smoothly, and be kept clean. Always support the body tube, while push- ing the draw tube in, and thus avoid pushing the objective into the slide. Substage: If the threads on the quick acting screw become gummed, and make it work hard, clean them with xylol or chloro- form until they work easily. Clean the leaves of the iris dia- phragm with the same substances if they become dirty or rusty. Then oil them and work it over all the parts by opening and clos- ing them several times. If the leaves become bent or misplaced have them repaired by a skilled mechanic or by the maker. When working with the diaphragm nearly closed make certain that no particles of dust or lint have collected in the edge of the opening and interfere with the light. Nosepiece: This is the part of the instrument that supports the objectives. When the nosepiece supports two or more ob- jectives the latter should be parfocal. That is, they should be made so that when one objective is in focus, the other also will be in fairly good focus if it is swung into the optical axis ; and 480 Bacterioi^ogicaIv Tests and Cultures the center of the field of one lens should fall within the field of the others. To obtain this result each set of objectives are fitted to a particular nose piece, therefore objectives should not be ex- changed. If the nosepiece is bent, the lens will be thrown out of center. Use care to avoid swinging the lens into the cover glass when changing from a lower to a higher power. When removing an objective from a nose piece always support it with one hand while screwing it off with the other and exercise every necessary precaution to prevent its injury. The Optical Parts. The- best results cannot be obtained with dirty lenses. In cleaning them remember that glass surfaces are soiled by coming in contact with the fingers. As the glass of the lenses is comparatively soft avoid rubbing it hard or using anything but soft clean cloth or lens paper in wiping it. Chamois skin should never be used for cleaning a lens. Japanese filter paper serves best. It is not expensive, and may be obtained from any dealer in microscopical supplies. Objective. Dust may be removed from the objective with a camel hair brush, or by wiping it with lens paper. Breathe on clouded lenses before wiping them. Kemaining cloudiness may be removed by wiping the lens with a corner of a piece of lens paper, or cloth that has been dipped in alcohol, then wipe dry. For oily substance, dampen the corner of the lens paper or cloth with chloroform, benzine, or xylol before wiping the lens, then wipe it dry. Clean immersion objectives with lens paper immediately after using them. If the immersion oil has dried on, use lens paper or cloth dampened with xylol or chloroform, theii wipe dry. Always keep an eyepiece in the tube to prevent dust from falling through the tube onto the back lens of the objective. Bust may be removed from this lens with a camel hair brush. An objective is too delicate and expensive to be repaired by any one but an experienced mechanic. If anything serious is the matter it should be returned to the maker for repairs. Oculars: These are cleaned by wiping in the same manner as described for objectives. If a gray film or specks of dust deposit on the inner surfaces of the lenses it will be necessary to remove the lenses from the tube and wipe them clean. OpiiRATiNG Tin-; Microscopf: 481 Condenser: It is necessary to have a clean condenser to enable the instrument to do its best work. In cleaning it, follow the directions given for cleaning the oculars. Mirror: Keep the surface of the mirror clean by applying the methods used in cleaning the lenses. Operating the Microscope: Location: The microscope should be placed on a firm table that is large enough to hold the neces- sary material without crowding. The table should be in a roomy place free from distracting influences, and of a height to make the position of the worker comfortable. The use of the inclina- tion joint and a chair, the height of which may be adjusted, will assist in attaining this object. When working on fluids it may be necessary to have the stage in a horizontal position. For this reason, it is advisable to become accustomed to using it in this position for all work. Practice working with both eyes open and divide the work by using either eye. By doing this, and not working too long in the beginning, several hours' work will not tire the eyes. If the eyes feel fatigued stop work until they are rested. Proper light- ing is a great help toward making the work easy for the eyes. Lighting : North light from windows without cross bars gives the best light. Direct sunlight is to be avoided, and should be toned down by using white shades on the windows if the sun- light strikes the microscope. Wire netting on the windows or branches of trees near them interferes with good work. In order to avoid shadows from the hands while manipulating the mirror or other parts, the operator should face the light, and use a screen to protect the eyes. Almost any strong artificial light that can be placed reason- ably near the microscope will serve well. It has the advantage of constancy, and may be used at all hours. Placing a bull's eye condenser between it and the mirror will assist. When examin- ing opaque objects it may be necessary to have the light shine directly upon the object in place of passing through it. For this work ordinary daylight, or daylight that is condensed upon the object by means of a lens or concave mirror, serves fairly well. Focusing: Place upon the stage directly' under the objective, a semi-transparent specimen having sharp outlines and mounted 482 Bactivriological Tksts and Cultures on a slide. With the ocular in place first use an objective of low power in focusing. While watching the objective lens from the side with the eye nearly on a level with the stage, turn the coarse adjustment to force the body tube down until the lens of the objective is almost in contact with the cover glass. Adjust the size of the opening in the diaphragm until the lighting effect is good but not too strong. . Then examine the field through the microscope while very slowly elevating tlie tube by means of the coarse adjustment, to bring the specimen into focus. When the specimen is clearly outlinetl, bring it into a sharp focus by using the fine adjustment. At this point move the mirror into different positions trying both the concave and plane sides, until the best lighting eft'ect is obtained. TJie fine adjustment will have to be used almost continuously to bring dift'erent parts of the specimen into the focal field while moving it around and examining it. Caution must be exercised at all times while focusing to avoid unconsciously forcing the objective through the cover glass on the slide. If it is necessary to obtain greater detail elevate the tube of the microscope by means of the coarse adjustment, then care- fully unscrew the objective and replace it with a higher power. If more than one objective is attached to a nose piece and they are parfocal, the nose piece may be turned without refocusing until the higher power objective is in the optical axis. While turning the nose piece, or while bringing the objective down close to the cover glass, look between the objective and the slide, and move the objective very slowly to avoid contact with the cover glass. If the specimen is not in focus after changing the objec- tive, it will be necessary to refocus as in the first instance. Two objectives and two oculars should be provided. Their magnifying powers, to order in purchasing, can usually be safely left to the maker of the microscope after explaining the character of the work in which they are to be used. Special Suggestions: It is a good practice for beginners to look through the microscope and examine the field with the slide removed. If specks or cloudiness are visible it may be due to dust or other material on the lenses. Specks on the ocular will move in the field when the ocular is revolved. Sometimes specks and filaments on the vitreous humor of the eye appear to be lo- Use of the Microscope 483 cated in the microscope field. No attention should be given to them. When examining fluids difficulty may be experienced in keeping objects in the field due to motion in the liquid. It should be remembered that specimens of considerable depth may change in form as the focal plane passes up or down. Particles at the bottom of a liquid may come into the focal plane and dis- appear as the objective and local plane are raised, other particles or crystals coming into view. Liquid used in mounting the speci- mens sometimes flows out and partly covers the cover glass, thus interfering with a clear field, or being mistaken for the liquid beneath the cover. Air bubbles are frequently found in the liquid mounts. A little experience will usually enable one to distinguish them from other objects. These are only minor troubles, and the remedies for them are obvious. OCULARS Objec- Initial Magnifi- Objec- tives tives mm. cation 4X oX 6X 8X lOX 12X 15X 20X mm. 48 2.2 8 11 13 18 22 27 33 44 48 40 2.8 11 14 17 22 28 33 42 56 40 32 4 16 20 24 32 40 48 60 80 22 30-32 2-4.5 4-9 5-12 8-19 10-24 15-35 18-43 20-48 30-70 30-32 25.4 6 24 30 36 48 60 72 90 120 25.4 16 10 40 50 60 80 100 120 150 200 16 12 15 60 75 80 129 150 180 225 300 12 8 20 80 100 120 160 200 240 300 400 8 5 36 144 180 216 288 360 432 540 720 5 4 44 176 220 264 352 440 528 660 880 4 3 60 240 300 360 480 600 720 900 1200 3 1.8 95 380 475 570 760 950 1140 1425 1900 1.8 1.5 109 436 545 654 872 1090 1308 1635 2180 1.5 THE USE OF THE MICROSCOPE IN DAIRY PLANTS. The microscope can be put to many important uses in dairy plants. These uses include the examination of solid particles found in milk or in its products ; the general physical appear- ance of all kinds of dairy products ; the examination of fat glob- ules ; the examination of milk sugar crystals, and finally com- plete bacteriological examination of all dairy products. The foregoing instructions are sufficiently comprehensive to enable one to operate the instrument for all minor microscopical examinations. Complete bacteriological examinations can be made only by those well versed in the subject. k 484 Bacterioi^ogical Tests and Cultures HOW TO MAKE MICROSCOPICAL EXAMINATIONS OF FAT IN DAIRY PRODUCTS. In the case of skim-milk, whole milk, and usuallj^ in the ease of cream, the samples can be examined without being diluted with water. Place a small drop upon the slide, and with the cover glass spread the same uniformly between the slide and the cover glass. Use samples of uniform size. In the case of evaporated milk, concentrated cream, sweetened condensed milk, and all other fluid condensed products, it is usually desirable to dilute the sample with an equal volume of water. This is best accomplished b}^ placing a small drop of the condensed product upon the slide, and then adding to it a drop of water of equal size, and mixing the two very thoroughly be- fore placing the cover glass over the same. The dilutions can be made in a flask using equal volume of the product to be examin- ed and water. The best results are obtained by using 10 X ocular and 4 mm objective. This will give a magnification of 440 diameters. HOW TO MAKE MICROSCOPICAL EXAMINATIONS OF MILK SUGAR IN DAIRY PRODUCTS. The products that usually contain crystallized milk sugar are principally sweetened condensed whole and skim-milk. Plain and skim condensed milk, if of too great concentration, also some- times contain milk sugar crystals. The defect in ice cream known as "sandy ice cream", is due to the presence of crystallized milk sugar. All of the above products should be examined without diluting with water, inasmuch as the addition of water might cause many of the crystals to go into solution. It is usually desirable to examine the crystals under both low and high magnifications. The two combinations most commonly used are 10 X ocular and 16 mm objective giving a magnification of 100 diameters ; and 10 X ocular and 4 mm objective, giving a magnification of 440 diameters. By means of the lower magnifi- cation, a large field of crystals can be examined, and the uniform- ity of the crystals carefully studied, while with the higher mag- nification the individual crystals are better defined, and the same can -be subjected to close study. Organisms Found in Mil,k 485 BACTERIA IN MILK. When milk is first secreted in the udder of a healthy cow, it is free from living organisms since these do not usually pass through the tissues of the digestive tract, and through those that supply the udder. As the milk descends in the udder it comes in contact with a few bacteria that probably gained entrance through the opening in the teat. Others are introduced later by dust from the air; by dirt from the hands of the milker; by particles of dirt or other material that fall into the milk; or by contact with bacteria on the walls of containers. Since milk affords a food supply in a condition readily avail- able for their growth, bacteria that gain entrance to it soon in- crease in numbers by reproduction, unless rigid measures are practiced to check their growth, or to destroy them. While all bacteria are considered objectionable in fresh milk, and some kinds are decidely harmful, some types are utilized to advantage in the manufacture of butter, cheese, and fermented milk products. For all of these reasons dairy bacteriology has been extensively studied, and methods of sanitary control de- veloped. The application of these methods adds considerably to the labor of handling milk, and to the cost of equipment for preserving it. The number of bacteria in a sample of milk ordinarily has little significance when the history of the sample is unknown, but where the bacterial count is high, and the sample's history is known, it may indicate that something is wrong, and thus be- come the basis for starting an investigation. Upon the other hand, a low bacteria count — other factors being considered, is usually an indication of good sanitary quality. The bacteria count and especially the determination of the kind of organisms present, is of unquestioned value to the industry for the purpose of locating and removing sources of contamination, and for measuring the effectiveness of sanitary methods. Types of Organisms Found in Milk. The organisms found in milk consist of bacteria, and usually a few yeasts and moulds. They comprise the lowest form of life in the vegetable kingdom, and like other plants, they must have suitable food and surround- ings in order to grow. As many bacteria are unable to move by 486 BacterioIvOGicaIv Tests and Cultures their own effort, and the others have only limited means of move- ment, all require a very moist, or liquid medium with a readily available food supply. Milk is a fluid of this character, and it meets the requirements of a number of varieties, although some after gaining entrance to it are unable to develop, and soon perish. Fig-. 115. Microscopic Siibstances Found in Milk, Sliowing Relatives Sizes, According to Melick.^ The above cut represents a portion of a drop of milk. F, fat globules ; L, leucocytes ; Y, yeast ; and B, b, c, s, t, 1 and 2 seven species of bacteria frequently found in milk. B represents the hay bacillus group ; b represents one species of bacillus viscosus which forms slimy milk ; c represents a streptococcus ; t represents bacillus typhosus ; 1 represents tetragenococci, and 2 one of the lactic acid group. Attempts have been made by a number of investigators to classify bacteria in groups, and describe varieties by their special properties. But' many difficulties have arisen because some of the properties of bacteria are transitory or extremely variable. It appears that permanent identifying characteristics, if they exist, are not understood with such clearness that it permits a satisfactory classification at present. The grouping that has been made, however, is used to advantage for the purpose of Orc.anisms Found in Milk 487 separation, study and description. The group name is usually derived from the most pronounced characteristics of the type. In this way the principal organisms that are nearly always present in milk may be placed in two groups, namely the Bacillus lactis acidi group, and the Bacillus lactis aerogenes group includ- ing Bacillus eoli communis. The members of the former group vary in their ability to produce lactic' acid but do not develop gas. The varieties that produce lactic acid and curdle the casenj rather promptly are most universally distributed. Their presence like the presence of all bacteria is very undesirable in all fresh milk, but in the form of pure cultures some are used to advantage in the manufacture of butter, most varieties of cheese, and sonr milk beverages. The characteristics of this group of organisms are described under S. lacticus Kruse, p. 490 and B. lactic acidi Leichmann, p. 491. The members of B. lactis aerogenes, and B. coli communis groups are frequently present in milk. They are very commonly the source of fermentations that cause trouble and loss to tVte dairy industry. Some of the varieties of these groups are de- scribed under Acid Gas Producers, p. 495. A group of liquefying organisms, characterized by their ability to liquefy gelatin, not uncommonly cause the loss of dairy prod- ucts. They digest casein and have the power to bring about decidedly putrefactive decomposition. B. Subtilis is a spoi-e- bearing organism of this type. It sometimes causes the decom- postion of evaporated milk that has not been properly sterilized. Also, the pronounced bitter taste that sometim.es develops in whole milk and in evaporated milk may be due to protein decom- position products developed through the action of the members of this group. Another group sometimes known as Bacterium caucasicum is of some importance in the dairy industry principally because a few types are used in the production of fermented milk bever- ages. The better known variety is Bacillus Bulgaricus. When used as a pure culture it yields a buttermilk having a sharp acid flavor and heavy body. Sometimes from 5 to 15 parts of the pure culture is added to 100 parts of a pure culture of Bacillus Lacticus in order to give the resulting buttermilk a more pro- nounced acid flavor and heavier body. The use of Bacillus 488 Bacterioi^ocicai, Tests and Cui.turi-:s Bulgaricus in the making of commercial cnltured bnttermilk is on the decline. Yeasts and torula are occasionally the cause of pronounced fermentation with production of gas in cream, is condensed milk, and in ice cream. In cream it causes foaming and prevents the fat globules from gathering in the churning process. It is liable to appear, with generous production of gas in sweetened condensed milk, and in ice cream when manufactured in un- sanitary surroundings or from infected products, and then held for a time. A few pathogenic organisms can live and develop in milk, and thereby disease may be transmitted to man. For this reason, their study is of importance in dairy bacteriology. The best protection for the public, however, is the practice of pasteurizing, and exercise of every reasonable precaution to keep the milk free from contamination. Wilcox'- drawing upon data from numerous sources con- cisely describes "the morphological characters, biology, and behavior of the pathogenic and saprophatic bacteria that have been found in milk". His description of several of the more important types are reproduced in the following paragraphs : PATHOGENIC BACTERIA MOST FREQUENTLY FOUND IN MILK. Bacillus tuberculosis Koch. Morphology. — fSlender, slightly bent, pointed ends, sometimes threads and branched forms, or club forms, longer in milk than in tissues, occurring singly or in twos, tliree or colonies. Size 1.5 — 4X .4m. (m = micron). Acid — fast. Gram and Ziehl-Neel- sen stains positive. No spores or flagella. Non-motile. Capsule stains. Bouillon. — Growtli in 7 or 8 days if glycerine is added. Sometimes pellicle. Glyceriue-agar. — Growth begins in 6-12 days. Colonies minute, whitish-yellow, later brown, lichen-like, elevated, sinuate, dry or moist. Potato. — Decided growth in 2 or 3 weeks, best if potato is moist, small crumb-like masses, friable, yellow, dull. Blood serum. — Growth begins in 10-12 days. Serum not liquefied. Colonies light, dry crumb-like coal- escing scales. Pathogenic for man and other animals. Aerobe. —Growth from 22° to 42° C, but best at ;{7= C. Organisms Found in Milk 489 B. typhosus Eberth. Morphology. — Takes ordinary stains, Gram stain negative. Short, plump, rods, longer in cultures. Size 1-3 X .6 — .8m. cap- sule. Motile, 8-14 long flagella. Occurs in threads. Serpentine movements. Vacuoles in stained and unstained preparations but no spores. Bouillon. — Turbidity, abundant sediment. Gelatine plates and tubes. — Small, yellowish-white, punctiform, raised center, wavy elevations under microscope. In stab cultures gran- ular, grayish-white thread growth. Streaks culture similar, non- liquefying. Agar plates and tubes. — Colonies irregular, round, grayish-white, slightly raised, yellow line extending outward from the center. In stab cultures granular, grayish, thread growth with irregular outline and oily lustre, later yellow. On streak cultures spreading, wavy, smooth edge, shiny. Milk. — Appearance unchanged, not coagulated, slightly acid. Potato. — Variable. Delicate and moist, grayish or rarely brownish. May be readily differentiated from B. coli by the fact that the latter coagulates milk within 48 hours with abundance of acid. B. typhosus grows best as aerobe but also as anerobe and in CO. Produces typhoid fever in man, and a fatal intoxication in animals. Grows best at 37° C. on all ordinar}^ media, less well on non- albuminous media. No pigment nor iiidol. No gas in lactose. B. diphtheriae Klebs-Loeffler. Morphology. — Slightly curved rods usually with one end club- shaped and the other pointed, or may be short wedge shaped, com- ma shaped, or dumb bell form. Size 1.2-2 X .3-. 5m. In groups of 2-4, no long chains. Stained by aniline dyes. Gram, Loetfler and Nicolle. Capsule. No flagella. Non-motile. No spores. Bouillon. — Dust like granules, usually pellicle. Produces indol, acid and nitrites. Gelatine. — Yellowish-white, slightly elevated surface, non-liquefying, non-characteristic. Agar plates and tubes. — In 24 hours circular, round, white elevated colonies with smooth edges and moist. Potato. — Little or no growth if acid, scanty after a few days if alkaline. Milk — Abundant growth, amphoteric reaction, no curdling. Blood serum. — Rapid at 37° C. Characteristic within 12 hours, round, raised, grayish-white colonies, yellowish, translucent if young, moist, margin irregular, center thickened and opaque. Colonies not confluent, may reach VJU Bactkriological Tests and Cultures size of 4 or 5mni, Abundant growth on hen's eggs. Grows best at 37* C. Qnickly killed at 60° C. Aerobe. Streptococcus of contagious mammitis. Morphology. — Long, undulating chains, elements Im in diam- eter, shorter in old than in recent cases of mammitis. Aerobe or anaerobe. Takes analine dyes, but Gram stain poorly. Gelatin. — Small, translucent, whitish colony. Pellicle. Potato. — Poor growth. Bouillon. — Growth after 24 hours. Sediment, no turbid- ity. Milk. — Rapid growth. Curdled in 24-48 hours, strongly acid. Causes mammitis in cows and goats. A smaller form causes gangrenous mammitis in sheep. Possible cause of sterpto- coccie sore throat in children. Streptococcus scarlatinae Klein and Gordon. Morphology. — Polymorphic streptococcus with all transition stages between coccus and bacillus. Coccus forms prevails in bouillon, bacillus on agar. Takes simple stains and Gram. Bouillon. — After 24 hours at 37'' C. a single, coherent, white-gray mass appears at base of tube, floating as a flat conglomerage in the fluid medium. Gelatin. — Slow, small, gray, circular, firm edge. No liquefaction. Chain formation conspicuous. Agar. — After 24 hours colonies are gray, granular, irregular, tubercula- ted ; or similar without tubercles ; or with a frill of chains around a compact center. Milk. — Rapid curdling, acid. Blood serum, — Good growth of colonies. Aerobe. Found in cases of scarlet fever and sometimes thought to be the cause of the disease. Occurs also in diseased udders of cows. Pathogenic for mice and rab- bits. BACTERIA PRODUCING ACID BUT NO GAS. Ordinary Types Most Frequently Found in Milk. S. lactis viscosus Conn. • Morphology. — A streptococcus. Size .8-. 9m. Gram stain posi- tive. Gelatin colon3\ — Shiny, pale, yellow, round or lobate, usually viscous. Gelatin stab. — Needle and surface growth, pro- ducing a nail culture. Agar streak, — Lobate, luxuriant, vis- cous. Fermentation tubes. — Acid in all sugar bouillons and growth in the closed arm but no gas. Bouillon. — Sediment, tur- bidity and pellicle. Milk. — Acidified, curdled and rendered very Organisms Found in Milk 491 slimy. Potato. — Luxuriant, dull, pasty growth. Grows at 20^ and 37° C. Facultative anaerobe. Variety A shows scanty, non- viscous growth on agar and no pellicle on bouillon. S. lacticus Knise. Morphology. — Long or short chains. Size .5-lm. Gram stain positive. Gelatin colony. — Minute, white, rough, dense. In lit- mus gelatin always acid. Gelatin stab. — Moderate needle grow^th, but no surface. Agar streak. — Barely visible, faint tilm. Fer- mentation tubes. — Acid in all sugars, usually growth in closed arm but no gas. Bouillon. — Almost invisible, slight sediment and turbidity. Milk. — Promptly acidified and curdled. Potato. — Uusually invisible. This species sometimes comprises 99 per cent of all the bacteria in a sample of milk. The type 8. lacticus I produces acid in dextrose but not in other sugars. Variety A of this type shows no turbidity but a slight pellicle in bouillon, • variety B, turbidity but no pellicle, variety C turbidity and pellicle with negative Gram stain, variety D luxuriant growth on potato. The type S. lacticus II produces acid in lactose and saccharose but not in dextrose. Gram stain negative. S. lacticus III shows pellicle on bouillon and acidifies or curdles milk. M. lactis Fluorescens Conn. Morphology. — Size .5 - .6m. Gram stain negative. Gelatin colo- n3\ — Round. Moderately thick, smooth, with greenish lique- faction. Gelatin stab. — Stratiform. Agar streak. — Luxuriant, narrow, thick, smooth, white. Fermentation tubes. — Dextrose acid, other sugars alkaline, no gas or growth in closed arm. Bouillon. — Sediment, turbidity, pellicle. Milk. — acidified, curdled, digested. Potato. — Scanty, thin, smooth, white. Grows at 20° and 37° C. Facultative anaerobe. M. lactis variens Conn. Yellow coccus, common in milk. Morphology. — Size .4-1.4m. Gram stain positive. Gelatin colony. — Deep and opaque or super- ficial and white, usually acid in litmus gelatin. Gelatin stab. — Napiform, liquefaction sIoav or rapid, sometimes a dry pit. Agar streak. — Luxuriant, rough, spreading pale orange. Fermentation tubes. — Acid in all sugars, closed arm growth, no gas. Bouillon. — Flocculent sediment, slight turbidity or pellicle. Milk — Acid, commonly curdled and digested. Potato. — Luxuriant or scanty^ 492 BacterioIvOGicaIv Tests and Cultures pale orange, frequently dry. Grows better at 37'' than at 20° C. Facultative anareobe. Variety A produces acid only in dextrose and does not acidify milk. Sar. lactis aurantiaca Conn. Orange, liquefying. Morphology. — Size Im, Gram stain posi- tive. Not motile. Gelatin colony. — Liquefying pit, orange pig- ment. Gelatin stab. — Slow liquefaction, stratiform. Agar streak. — Filiform, raised, smooth, moist, orange. Fermentation tubes. — No acid, gas or closed arm growth in any sugar. Bouillon. — Pel- licle, slight sediment. Milk. — No change in reaction, curdling, digestion. Potato. — Spreading, capitate, luxuriant. Grows at 20° and 37° C. Aerobe. B. lactis Viscosus Adametz. Slimy milk bacteria. Morphology. — Size. .5-1.2 x .5 - 2.5m. Filaments 15m long. Gelatin colony. — Flat, lobate, viscous. Gelatine stab. — Needle growth sometimes granular, thin, shiny, gray surface. Agar streak.— Luxuriant, viscous, white. Fer- mentation tubes. — No acid, gas or closed arm growth. Bouillon. — Sediment, turbidity, pellicle. Milk. — Alkaline, slimy, not curdled. Potato. — Thick, uneven, dirty gray. Grows at 20° and 37° C. Aerobe. B. lactis acidi Leichmann. Immensely numerous. Common cause of sour milk. Several varieties differing from type form. Morphology. — Size .7 - 1.2 x .5 - .8m. Sometimes cocci. Gram stain positive. No motility, spores or long chains. Gelatin colony. — Small points, opaque, not characteristic, mostly below surface. Acid on litmus gelatin. Gelatin stab. — Granular or linear needle growth, no surface. Agar streak. — No growth or barely visible, better on milk agar. Fer- mentation tubes. — Acid in all sugars, commonly closed arm growth, no gas. Bouillon. — Sometimes no growth, commonly slight sediment. Milk. — Acid, promptly curdled without gas, no digestion. Potato. — Thin, transparent or no growth. Grows better at 20° than at 37°. Facultative anaerobe. Variety A has a minute colony. Milk sometimes curdled in 6 hours. Variety B has a dense surface colony. Variety C is more anaerobic. Vari- ety D never curdles milk. Organisms Found in Milk 493 B. lactis burri Conn. Reddish bitter-milk organism. Morphology. — Size 1.3 x .7m. No chains, spores or Gram stain. Gelatin colony. — Surface in liquefying area 1-3 mm. in diameter. Gelatin stab. — Begins to liquefy in 4 days, infundibuliform. Agar streak.-j^Luxuriant, smooth, lobed, reddish. Fermentation tubes. — No acid, gas or closed arm growth. Bouillon. — Turbidity, no sediment or pellicle. Milk. — Acid, not curdled or digested. Potato. — No growth. Grows at 20°, not 37°. Aerobe. B. lactis fluorescens Conn. Morphology. — Size 1.4, - 1.5 x .8 - .9m. No chains, spores, capsule or Gram stain. Gelatin colony. — Slow, race-like, dense center. Gelatin stab. — Needle growth, stratiform, liquefaction in one day. Agar streak. — Filiform, translucent, smooth, white, green fluorescence. Fermentation tubes. — No gas or closed arm growth, acid in dextrose and saccharose. Bouillon. — Sediment, turbidity, pellicle. Milk, — Alkaline, curdled at 20° C, digestion. Potato, — Filiform, raised, white. Grows at 20°, poorly at 37° C. Aerobe. P. lactis varians Conn. Common in milk. Morphology, — Size 1 - 1,4 x 8m, Chains, No spores, capsules or Gram stain. Gelatin colony, — Round, flat or umbilicate, rugose, brownish. Gelatin stab. — Stratiform or infundibuliform, slow. Agar streak, — Filiform, raised, opaque, white. Fermentation tubes. — No gas or closed arm growth, usually acid in dextrose only. Bouillon. — Sediment, turbidity, membranous pellicle. Milk. — slightly acid and curdled at 20° C, not at 37° C. Potato. — Variable, white to brown. Grows better at 20° than at 37° C. Aerobe Variety A. liquefies rapidly. B. acidificans presamigenes casei Gorini and P. fragariae probably belong here. B. lactis citreus Conn. No chains or spores. Size .8 x .5m. Gelatin colony. — White, opaque, later yellow. Gelatin stab. — Needle growth, lemon — yel- low surface. Agar streak. — Luxuriant, lemon-yellow, smooth. Fermentation tubes. — Probably acid without gas. Bouillon. — Sediment, turbidity, pellicle. Milk. — Acid, curdles. Potato. — 494 Bacteriological Tksts and Culturi-s Luxuriant, white, then lemon yellow. Grows at 20° and 37^ C. Aerobe. B. lactis rubifacens Gruber. Bed pigment. Morphology. — Size 2 - 3 x .7m, Spores, no chains, capsule or gram stain. Gelatin colony. — Thick, gyrose, white. Gelatin stab. — Needle growth villous, spreading surface. Agar streak. — Linear, moderate, white. Fermentation tubes. — Acid and closed arm growth, no gas. Bouillon. — Sediment, turbidity, ring pellicle. Milk. — Acid, curdled like jelly. Potato. — Thick, white. Grows better at 20° than at 37" C. Facultative anaerobe. B. Subtilis. Very common in milk. Morphology. — Size 1.5 - 4 x .6 - 1,5 mm. Chains, spores, no capsule. Gram stain positive. Gelatin colony. — Rapid liquefaction, irregular granular masses. Gelatin stab. — Liquefies in one day. Crateriform, later stratiform. Agar streak. — Filiform, spreading, cretaceous, wrinkled. Fermentation tubes. — No acid, gas or closed arm growth. Bouillon. — Sediment, turbidity, pellicle. Milk. — Alkaline, curdled, digested. Potato. — spreading, gray, raised, dry or moist. Grows at 20° and 37° C. Aerobe. Varieties with slow liquefaction and negative Gram stain. This bacillus, — also frequently called "Hay Bacillus," on ac- count of having been first found in hay, as well as other members belonging to the same group to which this one belongs, are among the most important encountered in the dairy industry. Spoilage in the case of improperly sterilized evaporated milk is usually due to the presence of this bacillus. Fig. 116 and 117 illustrate this bacillus in two forms. B. lactis gelatinosus Conn, Produces jelly-like milk. Morphology, — Size ,8 x ,6 m. No chains, spores, capsule or Gram stain. Gelatin colony, — Round, smooth, white, slow. Gelatin stab, — Slow, crateriform, white. Agar streak. — Filiform, raised, smooth, brownish. Fermentation tubes, — No acid, gas or closed arm growth. Bouillon. — Sediment, turbidity, membranous pellicle. Milk. — Acid, curdled, digested into jell3^ Potato, — Moderate, raised, brownish. Grows at 20° and 37° C, Aerobe, Organisms Found in IMilk 495 B. mesentericus fuscus Conn. Morphology. No chains. Size 1.2 - 1.5 x .4 - .6m. Central spores, gram stain positive. Gelatin colony. — Round, convex, en- tire, brownish-red. Gelatin stab. — Slow, napiforra. Agar streak. — Spreading, thin, rugose, gray. Fermentation tubes. — o gass or closed arm growth. Acid in dextrose and saccharose. Bouillon. — rig-. 116. Bacillus Sutotilis." Vegretating- Rods from a Very Young Culture of Ag-ar. Bacilli Showing Flagella. nfii^ts 1 >' * Fig: 117. Bacillus Subtilis and Spores.' The Spores Have Very Thick Cell Memhrane Almost Impenetrable by Heat, 496 Bacteriological Tests and Cultures Slight turbidity, no sediment or pellicle. Milk. — Alkaline, curdled, digested. Potato. — Luxuriant, thin, rugose, brownish- red. Grows better at 37° than at 20'' C. Aerobe. ACID GAS PRODUCERS. Bacterium aerogenes type. B. lactis aerogenes Esch. Morphology.— Size 1.4- 5 X 1 -1.5m. Sometimes capsule. No chains or spores. Gram stain irregular. Gelatin colony. — Thick, round, smooth, moist, sometimes viscous, 2 mm. in diameter. Gela- tine stab. — Needle growth, thick, white surface. Agar streak. — Luxuriant, moist, gray. Fermentation tubes. — Acid, gas and closed arm growth in all sugars. Bouillon. — Sediment, turbidity, usually pellicle. Milk. — Strongly acid, curdles, gas. Potato. — Luxuriant, dirty white. Grows better at 37° than at 20° C. Aerobe. No indol. One variety produces indol, a second a thick colony, and two others bitter milk. The Coli Communis type. B. Coli aerogenes Conn. Flagellate. Morphology. — Size 1-3x1- 1.4m. No chains, spores or Gram stain. Gelatin colony. — Prominent, thick, smooth, moist, large. Gelatin stab. — ^Needle growth, thick white surface. Agar streak. — Filiform, raised, smooth opaque. Fermentation tubes. — Acid, gas and closed arm growth, not much gas. Bouillon. — Sediment, turbidity, usually pellicle. Milk. — Strongly acid, curdles with gas. Potato. — Luxuriant, white or straw color. Grows better at 37° than at 20'' C. Aerobe. Indol produced, or sometimes not. B. coli communis Esch. Like the last species, but produces a thinner, umbonate colony on gelatin with a granular lobate edge. Indol is produced. B. coli is very common in milk on account of the frequent contamina- tion with feces. Typical characters. Morphology. — Size l-1.6x.4-lm. No chains, spores, capsule, or Gram stain. Flagella peretrichic. Gela- tin colony. — Thin, spreading umbonate, smooth center, lobate. Gelatin stab. — Filiform needle growth, spreading, moderate sur- Organisms Found in M11.K 497 face. Agar streak. — Filiform, raised, smooth, white, sometimes lobed. Fermentation tubes. — Acid, gas, and closed arm growth in all sugars. Bouillon. — Turbidity, sediment, ring pellicle. Milk. — Acid, curdling, no digestion. Potato. — Moderate, smooth, gray- white. Grows better at 37° than 20° C. Aerobe. Indol produced. One variety produces gas in dextrose only, and another renders milk slimy. P. Coli communis Conn. Gas-producing Pseudomonas. Morphology. — Size 1 - 1.5 x .8 - .9m. No spores, chains, capsule or Gram stain. Gelatin colony. — Round, thick, smooth, auriculate, gray. Gelatin stab. — Fili- form, umbonate, bluish sui-face. Agar Streak.— Moderate, linear, raised, gray. Fermentation tubes. — Acid, gas and closed arm growth. Bouillon. — Sediment, turbidity, flocculent pellicle. Milk. — Acid, curdling, no digestion. Potato. — Moderate, thin, spread- ing. Grows better at 20° than at 37° C. Facultative anaerobe. Almost identical with B. coli communis except that there is only one flagellum, which is long and characteristic. Common types of fungi found in milk. In addition to the bacteria which may occur in milk and cause various changes in it a number of fungi other than bacteria may gain entrance to milk. Of these perhaps Oidium Lactis and Torula amara are most common. Brief descriptions of these fungi may be given in this connection. Oidium lactis. This is the conidial form of a mildew belonging to the same geJius with the powdery mildew of the grape. It occurs normally in sour milk. Morphology. — Fruiting hyphae simple, erect, color- less, bearing at the tips chains of conidia which germinate to form septate hyphae. Takes ordinary aniline stains. The spores or conidia are short cylinders. Gelatine. — Colonies at first white points, becoming stellate and finally covering the entire surface with a mycelial network. Makes similar growth on agar. Torula amara Harrison. Morphology. — Oval cells. 7.5 - 10 m. long, showing vacuola- tion after a few days, budding at smaller end of cell. Singly or in clumps or chains. No spores. Wort. — Abundant growth at 498 Bactkriologicai, Tksts and Cultures 25° C. No pellicle. Yeast rings form at 37° C. Wort Gelatin. — Pin-point colonies becoming round and grayish white in 4 days. Gelatin stab. — Beaded line becoming dense and spiny. Surface waxy becoming brown at center. Wort Agar. — Rapid, luxuriant. Agar. — Glistening, flat. Potato. — In 3 , days slightly raised, yel- lowish growth. Milk. — Bitter in 5 or 6 hours, curdled in 10 days, much gas, no butyric acid, QUANTITATIVE DETERMINATION OF ORGANISM IN MILK. Laboratory and apparatus : The suggestion given in Chapter I should be found helpful in fitting out a small laboratory but much will depend upon the ingenuity of the individual, the space avail- able, and the funds that may be used for purchasing equipment. Where a room is used for a variety of purposes, there is likely to be an excess of dust whereas bacteriological work should be carried on in a place as free from dust as. possible. It would therefore be well to x>artition off a portion of the room where sterile apparatus and the reagents may be kept and the plating and other work may be done. As plenty of light is necessary, the partitions may be made largely of glass. The autoclave or steam sterilizer should maintain a steam pressure of at least 10 pounds to insure convenient and'reasonably quick means for thoroughly sterilizing the media and water. Any kind of an oven that can be maintained at a temperature of 175° C will serve as a sterilizer for glassware. It should be fitted with a thermometer. An incubator, in which the temperature can be accurately controlled is indispensable. It is much better to purchase a good one especially designed for the purpose than to try to use a cheaply built substitute. Methods : The American Public Health Association published in 1921 Standard Methods for the Bacteriological Examination of Milk.'' As these methods are representative of the best work in America they are given here.'' COLLECTION OF SAMPLES FOR BACTERIOLOGICAL COUNTS. Although the technique of the plating method is funda- mentally dift'erent from that involved in microscopic counting, microscopic counts are readily made from the same samples as those used in making agar plates. As the precautions necessary Cor.Livcriox or Sami'Lf:s 499 for securing a fair sample are identical, the method of collecting- samples for both methods are des bribed under a single heading. All collecting apparatus, glassware, pipettes, collecting tubes, bottles, etc., shall be sterilized at a temperature of at least 175° C. for one hour. Each sample shall consist of at least 10 cc. of milk. Before taking the sample the milk shall be mixed as thoroughly as pos- sible. If the original container can be inverted the mixing of the milk should be done by inverting it several times. If this is impossible, the milk should be stirred wth some sterile stirrer. Any stirrer already in the container may be used. If there is none in the container, the sampling pipette (or any other sterile article) may be used ; but it shall be used for one container only until it is again sterilized. A sample merely poured from a large can is not a fair sample unless the milk in the can is thoroughly stirred. Neither is a sample of mixed milk, taken after it is poured into an unsterilized weighing vat, a fair sample from which to judge the quality of the milk before it was poured into the vat. The sample shall be taken from cans by means of a glass or aluminum tube with straight sides, long enough to reach the bottom of the original container and inserted, not too rapidly, with the top of the tube left open. This will result in the tubes containing a cylindrical section of the milk from top to bottom of the can. The finger then placed on the top of the tube will make it possible to with- draw the tube full of milk and transfer it to the sampling bottle. The sampling bottle should be large enough to hold the entire contents of the tube, all of which must be reserved as the sample. Each tube shall be used for collecting a single sample only, and must be washed and sterilized before it is used again. If the sample is taken from a bottle, the bottle should be first shaken to ensure thorough mixing and the milk may be poured into the sample bottle, although it is better here also to use a sampling tube. If the temperature of the milk is desired, it should be taken from a different container from that used for the bacteriological sample, or after the bacteriological sample has been withdrawn. All records shall be made immediately after taking the sample. The milk sample shall be placed in a properly labeled bottle. The 500 Bacterioi^ogical Tests and Cultures most convenient kinds of sample bottles are glass stoppered, or those closed with a cork lined screw cap. Cotton plugs are not satisfactory method of closure. The sample bottles shall be placed at once in a carrying case containing cracked ice, so that the milk is promptly cooled to near the freezing point. The samples shall be transferred to the laboratory as quickly as possible and shall be plated with as little delay as possible. The samples placed in cracked ice and water may be kept for several hours (12) without an appreciable increase in bacteria. If the plates are not made within four hours from the time of collection, the number of hours that did elapse should be stated in the report. If the milk is kept at 40° C. a slight and somewhat variable increase may be found in twelve to twenty hours. Up to twenty hours this will not be more than 20 per cent in normal cases. The larger increases may be expected in milk which has been stored at low temperatures for some time previous to sampl- ing. Continued shaking of the milk during its transit to the laboratory tends to break up the clumps into smaller masses and so increases slightly the number of colonies. In the case of samples to be used for direct microscopic examination, icing of the samples may be dispensed with under some conditions where it is possible to add preservatives (forma- line 2 to 3 drops of a 40 per cent solution of formaldehyde for each 10 cc. of milk) to the samples as taken. Samples containing pre- servatives that have been allowed to stand until the cream is compact are not satifactory, and are likely to give a lower count than fresh samples. (A) MACROSCOPIC COLONY COUNT (PETRI PLATE METHODS). Composition of medium. Standard beef extract agar* shall be used for all routine work and shall contain the following ingredients :** Agar (oven dried) 1.2% or *Beef infusion may be substituted for beef extract in those laboratories where past records are based on the use of beef infusion agar; but in the interest of uniformity, it is urged that beef extract be used. **Thi,s medium is essentially the same as that recommended in the last edition of the Standard Methods of Water Analysis except for the reaction preferred. Composition of Medium 501 Agar (market) *. 1.5% Beef extract ' 0.3% Peptone 0.5% Distilled water The beef extract shall be Liebig's where this is obtainable, or some other brand giving comparable results. Witte peptone, if available, can be used with assurance that the reaction of the medium will be neutral (pH=7.0) ; other brands — such as Armour's, Digestive Ferments Co.'s, Parke Davis Co.'s, — although more acid can often be used for milk analysis without necessitating change of reaction ; and nearly any good commercial peptone may be used with comparable results pro- vided special attention be given to H-ion concentration of the medium. The agar must be of the best quality. If oven-dried at 105° C. just before using, take 1.2% ; if used just as obtained in the market without oven-drying, use 1.5%. Remove salts and any dirt present by soaking, washing and draining. Distilled water is to be used for dissolving the ingredients. Reaction, A medium consisting of the above ingredients, including a suitable peptone, ordinarily has a reaction between pH^6.2 and 7.0. If within these limits, the reaction requires no adjustment for m.ilk analysis. The most desirable reaction is about pH=6.5 to 6.6 ; but any reaction between pH^6.2 and 7.0 is allowable. No change in reaction should be made without carefully deter- mining the H-ion concentration of the finished medium by the method described below. Inasmuch as the range of H-ion concentration recommended for water analysis^ is pH==6.8 to 8.4, it is permissible, if desired, to use a single agar for both purposes with a reaction of pH=6.8 to 7.0. If Witte's peptone is used in the above formula, this will ordinarily be the reaction without adjustment. Each batch of finished medium should be tested before use as to its final reaction after sterilization. This test is to be made as follows : Put 4 cc. of distilled water at 30 to 40° C. (not warmer) in a test tube. Add 1 cc. of the agar to be tested and then 10 drops 502 BacterioIvOGical Trsts and Cultures of the indicator, brom thymol blue* (0.04 per cent solution in 95 per cent alcohol). The resulting color should be either a yellowish green or vary to a deeper shade of grass green. To one whose eye is trained this shade of color is sufficient. These shades may be accurately determined by means of the buffered solution'' of Sorensen or of Clark and Lubs. However, they may be approximately determined by comparing the tube of agar containing the indicator with a set of color tubes after the method of Barnett and Chapman.^" Select 12 test tubes of even caliber and place in two rows of 6 each. In each tube of one row put 5 cc. of a dilute alkali (as, for example, twentieth normal sodium hydroxide). In each tube of the other row put 5 cc. of very dilute acid (one drop of con- centrated sulphuric or hydrochloric to 100 cc. of distilled water is sufficient). Avoid stronger acid. Add indicator to the tubes as follows : Acid tubes Alkali tubes H-ion concentration 9 drops 1 drop pH 6.2 8 drops 2 drops pH 6.4 7 drops 3 drops pH 6.7 6 drops 4 drops pH 6.9 5 drops 5 drops pH 7.1 4 drops 6 drops pH 7.3 The tubes are to be viewed in pairs of acid and alkali, each pair containing the sum of ten drops of indicator. If preferred, double these quantities may be used throughout and the indicator measured in fractions of a cubic centimeter instead of drops. That is, two cc. of agar should be taken for testing. This should be added to 8 cc. of distilled water. One cc. of indicator should be used. In comparing with the Barnett and Chapman tubes, use 10 cc. of dilute acid or alkali in each tube, and add the indicator in tenths of a cubic centimeter instead of in drops. All of the test tubes used in this determination must be of the same diameter and of clear glass. •Prepared by Hynson, Wescott & Dunning, Baltimore, Md. Pri;paration of Agar 503 Another indicator, brom cresol purple,* (0.04 per cent solution in 95 per cent alcohol) may be used as an alternative for brom thymol blue. Its use is especially desirable if the reaction of the agar is more acid than pH=6.4, because brom thymol blue is not very sensitive at this point. Brom cresol purple, on the other hand, is not sensitive at pH=::7.0 and therefore cannot be used if the medium is of neutral reaction. The pH values corresponding to the color pairs (acid and alkali) prepared by the method of Barnett and Chapman have been worked out b}^ Medalia.^'^ The color of brom cresol purple is a good shade of purple at pH=6.8 with increasingly lighter shade to pH=6.2. At pH=6.0 the color is a grayish hue not easily confused with that of pH==6.2. Adjustment of reaction. If the correct color of the indicator does not appear in the agar as tested, add dilute NaOH (e. g. N/20) from a burette until the shade is obtained which represents the desired H-ion concentration, that is between pH=:6.8 and 7.0. Fifty times the amount of N/20 NaOH added from the burette equals the amount of normal NaOH to be added to one liter of the medium if 1 cc. of the agar is being tested. When testing 2 cc. of agar, multiply by 25 instead of 50. In this adjustment, it is permissible to use any strength NaOH, but the strength of that added to the medium must be an exact multiple of the strength of NaOH used in titration ; if the ratio is not 1 :20 proper allowances must be made. Method of preparing agar. The important point is to secure an agar of the correct re- action and composition which contains no troublesome precipi- tates. Methods of cooking and filtering to accomplish this vary with the ingredients used. Those suggested below have been found satisfactory in practical use ; but other methods securing the same results are allowed. White of egg, however, must not be used for clarification. The finished medium may be tubed or bottled, placing 10 cc. in each tube or 55 cc. (enough for five plates) in each bottle. •Prepared by Hynson, Wescott & Dunning, Baltimore, Md 504 Bacteriological Tests and Cultures Sterilization shall be accomplished by heating in the autoclave for 20 minutes after the pressure reaches 15 lbs. ; or after the agar is completely melted, heat in flowing steam on three successive days for 20 minutes each day. All glassware and all apparatus such as kettles, funnels and filtration flasks, must be kept scrupulously clean by running hot water over or through them after use before the agar has had time to harden. There is danger otherwise of dried particles of agar chipping off and giving rise to sediment in future batches of agar which in the poured plates may be mistaken for colonies. Procedure No. 1. Mix all of the ingredients together cold. Heat in an autoclave at 15 lbs. pressure for 40 to 90 minutes according to the quantity of medium being made in each batch. Allow the autoclave to cool very slowly so as not to disturb the sediment. Decant through a cotton filter taking care not to pour the sediments on the cotton until the bulk of the liquid has passed through. This simple procedure with certain brands of peptone and grades of agar gives excellent results. Procedure No. 2. Where large quantities of agar are to be prepared the following procedure has been found useful. Pre- pare two separate solutions : Mixture A. — Beef extract 0.3 per cent of total quantity of medium to be made. Peptone 0.5 per cent of total quantity of medium to be made. Distilled water 40 per cent of total quantity of medium to be made. Place in a kettle. Weigh kettle with contents. Heat on stove to boiling, and boil five minutes. If absolutely necessary to adjust reaction (see Reaction) do so at this point and boil again. Make up with hot distilled water that lost by evaporation. Do this by weight. Filter through paper or paper pulp in a Buchner funnel (see below). Mixture B. — Agar oven dried 1.2 per cent (market 1.5 per cent) of total quantity of medium to be made. Soak and wash under tap in sieve. Weigh before and after soaking to determine quantity of water absorbed. Distilled water 60 per cent of total PrKparation 01? Agar 505 quantity of medium to be made, minus that absorbed by the agar during the washing. Mix A and B (agar not yet melted). Heat mixture over stove, stirring at frequent intervals until agar is entirely melted. Then boil and stir constantly for 20 minutes. Make up by weight water lost by evaporation by adding liot distilled water. Keep kettle of agar in chamber of flowing steam while preparing funnel for filtering. Filter through cotton until clear. For 10 liter amounts it is suggested that either a Sharpies centrifuge or a nine inch Buchner funnel with a suction pump be used. The ordinary filtration pump attached to a water faucet producing about 11 inches of vacuum gives good results. Prepare paper pulp by soaking scraps of ordinary filter paper for 36 to 48 hours in a large w4de-mouthed bottle. The paper and water should be in the ratio of six sheets of soft absorbent filter paper (20 by 20 inches) to 2^/2 liters of hot water. Moisten the paper and tear it into fragments about ^ to 3^ inches square. Shake vigorously at intervals to make the suspension fine and uniform. When ready to prepare the nine inch funnel, take 400 to 500 cc. of the paper pulp and dilute it with about three liters of very hot water. Cut a piece of surgeon's lint (or cotton, flannel) to fit the bottom of the funnel exactly. Rinse the funnel with hot water. Place in it the lint with the fleecy side upermost. Pour in the hot paper pulp suspension carefully so as to cover the lint Avith an even layer about }i to 34 ii^cli thick. Over this lay a disk of filter paper. Place a four liter suction flask under the funnel and apply the suction to draw the water into the filtration flask until the pulp is firm, yet somewhat moist. The agar will not go through too dry a filter. The funnel and the paper pulp must be hot when the agar is poured in carefully and slowly, striking the disk of filter paper which prevents the breaking of the surface of the paper pulp. Discard the first 100 cc. of agar which come through as they con- taih some of the water from the pulp. Even in the first filtration the agar should come through very clear. Keep the remainder of the unfiltered agar hot in flowing steam while the first part is rumiing through the filter. 506 Bactkriological Trsts and Cui^turrs Ordinarily the temperature of the agar in the funnel is 80° to 85° C. but the last portions will come through well as low as 50° to 55° C. Keep the filtered agar hot in flowing steam while preparing a second funnel in the same way as the first. Then filter as before. Plating. For miscellaneous milk samples, the character of which is not known, three dilutions shall be made; 1 : 100, 1 : 1,000 and 1 : 10,000. Where the character of the milk is known, the number of dilutions may be reduced. If the milk is pasteurized, certified or known to be fresh, and of high grade, the 1,000 and 10,000 dilutions may be omitted. If the milk is knoAvn to be old and of high bacterial count, the 100 and 1,000 dilutions may be omitted, and dilusions in excess of 10,000 prepared. In no case shall less than two plates be made from each sample. Where two satis- factor}' plates are obtained it is advisable to count both of them. The water used for dilutions may be placed in dilution bottles (99 cc, 49.5 and 9 cc. are convenient sizes) are sterilized for one hour in an autoclave at 15 lbs. pressure. The bottles should be marked so that it can be determined that they have neither gained nor lost water during or subsequent to sterilization. Or, the water may be sterilized in bulk, if kept in a properly guarded container, and subsequently measured directly into the dilution bottles with sterilized pipettes. The dilution bottles should have glass or cork stoppers, or some other type of closing that makes shaking possible. Cotton plugs are a less satisfactory method of closure because a small portion of the dilution water will soak into the cotton.^ - Straight sided pipettes graduated to deliver 1 cc, are the best. They may be either the two mark or the one mark style. In either case, the errors of measurement are caused more by faulty calibration or by faidty manipulation of the pipettes than by the particular form of pipette used. In using two mark pipettes, great care must be taken to see that the quantities used are exactly 1 cc, while many one mark pipettes in use are calibrated to contain 1 cc. rather than to deliver 1 cc. Breakage of tips of the latter type of pipette also cause errors. Plating 507 In making dilutions the original sample and each dilution bottle shall be rapidly shaken 25 times, each shake being an up and down excursion of about one foot (entire shaking not to take longer than about seven seconds). After the final dilution fill a pipette to the mark and allow contents to run into an empty petri dish, the end of the pipette touching the dish as the liquid runs out. If the pipettes are of the one mark style be sure that they are so manipulated as to deliver a full cubic centimeter. Use care to raise the cover only as far as necessary to insert the end of the pipette. Pipette should be placed immediately in water after using to make subsequent cleaning easier. The flasks (or test tubes) of agar shall be melted in boiling water or steam and after melting shall be cooled to a temperature of between 40 and 45° C. before using. Pour about 10 cc. of the melted agar in each inoculated petri dish, and by a gentle rotary motion thoroughly mix the agar and the diluted milk. As nearly as possible the same amount of agar should be poured into each petri dish so that the depth of agar will be uniform in all. If desired 10 cc. may be measured out from the flask with a sterile pipette. It is important that the plating shall be completed as rapidly as possible. The work should be so planned that no more than 15 minutes shall elapse after the dilution of the milk and before the agar is poured into the petri dishes; and in no case shall the interval be allowed to exceed 20 minutes. After the agar has been thoroughly hardened, place the petri dishes in an incubator. The danger of spreaders may be reduced either by the use of clay tops or by inverting the plates as pre- ferred. Incubation. Only one period of incubation, and one temperature is regard- ed as standard, 48 hours at 37.5° C. Piles of plates should not be packed too closely together and in crowded incubators ventila- tion should be provided. Counting Plates. If among the different dilutions there are plates containing from 30 to 300 colonies these should be counted,^^ and the num- 508 Bacterioi^ogical Tests and Cultures ber, multiplied by the dilution, be reported as the final count. All colonies on such plates should be counted, and the numbers from the different plates averaged. If there are no plates within these limits, the one that comes the nearest to 300 is to be counted. No plate that contains less than 20 colonies shall be counted, unless it happens that there are no other plates. If the number of col- onies on the plates to be counted are in excess of 300 per plate, a part of the plate may be counted and the total number estimated ; but such plates are admittedly overcrowded and the counts are less than they should be. Countings shall be done with a lens, and all recognizable col- onies included. A lens magnifying 2^ diameters (or what the opticians call a 3j/2 x lens) is recommended for general use. In case any particles visible by this method are of doubtful nature they should be examined with a compound microscope to deter- mine whether they are colonies or dirt specks. Common sources of error in counts. Agar plate "counts" per cc. are to be regarded as estimates of numbers rather than as exact counts, since only a portion of a cubic centimeter is used in preparing the plates. As such they are (like all estimates) subject to certain well known and recog- nized errors whose size can be largely controlled by the care taken in the analysis. Among these errors are : (a) Failure of some of the bacteria to grow because the incubation temperature, or the composition reaction of the medium, is not suitable, (b) Inac- curacies in measurement of the quantities used, (c) Mistakes in counting, recording data, computing results and the like. (4) Incomplete sterilization or contamination of the plates, dilution waters, etc. The possible errors caused by these things makes it highly important for all routine laboratories to follow carefully a standard procedure. Recent investigations make it clear that these largely control- able errors, are not likely to cause serious misconceptions of the accuracy of results as are the errors due to the fact that bac- teria in milk usually cling together in groups of from two to many hundreds of individuals. These groups are only partially broken apart by the shaking given in preparing the dilutions so that at best the counts from the agar plates represent the number of isolated individuals and groups of two or more bacteria that RiiPuRTiNG Results 509 exist in the final dilution water. Thus the colony counts from the plates are always much smaller than the total number of bac- teria present. This error would not be troublesome if the groups were of constant average size ; but the best information available shows that the groups in ordinary market milk commonly vary in size so that they contain an average of from 2 to 6 individual bacteria. Some samples contain groups of even smaller size than this, while others, such as those bearing long chain streptococci, may show groups containing an average of 25 or even more in- dividual bacteria. The irregularity of this error (whose size is not indicated in any way by the appearance of the plates) should be kept in mind in interpreting the results obtained. Reports. Because of the fact that agar plate counts only represent a fraction of the total number of bacteria present, they should not be reported as showing the ''number of bacteria per cc." Ac- curately speaking the counts from agar plates give the estimated number of colonies that would have developed on standard agar per cc. of milk if an entire cubic centimeter of milk had been used for inoculation. Because this statement of fact is cumber- some, and also because a certain ratio exists in each case be- tween the colony count and the total number of bacteria, it has become a common practice to speak of the plate counts as showing the number of bacteria per cc. This is very confusing now that microscopic methods of counting have been developed which per- mits counts of the actual bacteria to be made. These counts average approximately five times the size of the counts as made by the standard agar plate technique. It is therefore recommended that all agar plate counts obtained by the standard technique shall not be stated in the form "2,000,- 000 bacteria per cc." but rather as follows : "official plate count, 2,000,000." This latter form of expression shall be considered an abbreviated method of saying : " a count of 2,000,000 colonies per cc. as obtained by standard methods." Moreover analysts shall be careful to avoid giving a fictitious idea of the accuracy of the official plate count. There is ample justification for thinking them sufficiently accurate to justify drawing conclusions as to the general quality of a given sample of milk, and when a series 510 Bacteriological Tlsts and Cultures of samples from the same source are examined the average result may permit much more specific conclusions to be drawn with confidence. Specific data showing the actual percentage error in these counts has been difficult to obtain, and has only recently been obtained by means of comparisons made between microscopic and agar plate counts. The conclusions reached by Breed and Stocking are that the margin between two plate counts made from similar samples of marketed milk must be as great as one to five before it becomes a practical certainty that the larger count actually repre- sents the larger number of bacteria. It is, however, self evident that between any two samples the one having the higher count probably contains the greater num- ber of bacteria, and this probability can be made a practical certainty by the examination of a series of samples. It is there- fore required that a series of samples, preferably four or more, be examined before judgment shall be rendered as to the general quality of a given milk supply. Under no conditions is the practice sanctioned of publishing exact counts from individual samples as showing the quality of a given milk supply. All laboratories conforming to standard procedure will keep a record of the exact number of colonies developed on the plates that are counted ; but will render their reports in round numbers only. Never use more than two significant left hand digits in any report, raising the number to the next highest round number in any case ; but never lowering it. Those wishing to be still more conservative may use a form of report such as "official plate count less than 10,000," "official plate count between 10,000 and 30,000," and the like. STANDARD METHODS OF BACTERIAL MILK ANALYSIS. Plating apparatus. For plating it is best to have a water bath in which to melt the media and a water jacketed water bath for keeping it at the required temperature ; a wire-rack which should fit both the water baths for holding the media tubes ; a thermometer for recording the temperatur(^ of the water in the water jacketed bath, a sterile DlI,UTlONS 511 one c. c. pipette, sterile petri dishes and sterile dilution water in measured quantities. Dilutions. Ordinary potable water, sterilized may be used for dilutions. Occasionally spore forms are found in such water which resist ordinary autoclave sterilization ; in such cases distilled water may be used or the autoclave pressure increased. With dilution water in eight-ounce bottles calibrated for ninety-nine cubic centi- meters, all the necessary dilutions may be made. Short wide mouthed "Blakes" or wide mouthed French square bottles are more easily handled and more economical of space than other forms of bottles or flasks. Eight ounce bottles are the best, as the required amount of dilution water only about half fills them, leaving room for shaking. Long fibre, non absorbent co'tton should be used for plugs. It is well to use care in selecting cotton for this purpose to avoid short fibre or "dusty" cotton, which gives a cloud of lint-like particles on shaking. Bottles and tubes should be filled a little over the 99 c. c. and 9 e. c. marks to allow for loss during sterilization. The 'dilutions recommended are 1-10, 1-100, 1-1,000, 1- 10.000, 1 - 100,000, and 1 - 1,000,000. For certified milk the 1 - 100 dilution should be used, while 1 - 100 and 1 - 10,000 will usually be found best for market milk. The 1-10 dilution is prepared by shaking the milk sample twenty-five times and then transferring 1 c. c. of the milk to a test tube containing the 9 c. c. of sterile water. The 1 - 100 dilution is prepared in the same way, except that a bottle with 99 c. c. of sterile water is substituted for the test tube. The 1 -1,000 dilution is prepared by first making the 1 - 100 dilution, shaking twenty-five times and, transferring 1 c. c. of the dilution to a test tube containing 9 c. c. of sterile water. The 1-10,000, 1-100,000, and 1,000,000 dilutions are made in the same manner by dilutions of 1-100, 1-1,000, and 1-10,000 dilutions, 1 c. c. to 99 c. c. of sterile water. It is recommended that that dilution be used which will pro- duce about 200 colonies to a plate, ranging from 40 - 200 where a 1-10 dilution exceeds this number the 1 - 100 dilution is more 512 BacterioIvOGicaIv Tests and Cultures accurate, etc. The number of bacteria present may if desired, be approximately estimated before dilutions are made by direct microscopic examination of a properly prepared sediment. Otherwise, it is necessary to make a range of dilutions thereafter selecting for record the count obtained on that plate which yields between 40 and 200 colonies. Plating whole milk is unreliable, whatever quantities be used, since the bacteria are not so well separated as in the dilutions, and often, owing to the crowded conditions, only a portion of the bacteria present will develop into visible colonies. Moreover, if a cubic centimeter of the milk is used, the turbidity of the jelly due to the presence of the milk hides the colonies present from the eye. Porous earthenware Petri dish covers are recommended as superior to glass since they absorb the excess moisture. They also have the advantage of being cheaper and more durable than glass, they are easily marked with ordinary lead pencil. With long incubation a tendency of plates with these covers to dry out has been observed by some workers ; for ordinary routine work, however, they are perfectly satisfactory using 10 c, c. of media to the plate and incubating in a saturated atmosphere. These covers should never be washed but always thoroughly dry sterilized before use. Another method of preventing spreaders is by inverting the dishes and placing in the glass cover of each a strip of sterile filter paper moistened with one large drop of glycerine. Plates so treated do not dry out as quickly as with the porous tops and the glassware does not become scratched. Pipettes. Straight sides 1 c. c. pipettes are more easily handled than those with bulbs ; they may be made from ordinary 3-16 inch glass tubing and should be about 10 inches in length. Plating Technique. The agar after melting should be kept in the water jacketed water bath between 40 degrees C. for at least fifteen minutes before using to make sure that the agar itself has reached the temperature of the surrounding water. If used too warm the heat may destroy some of the bacteria or retard their growth. CoNTRor.s 513 For routine work in cities in order to bring down the actual number of colonies in a plate to about the standard of two hundred, it is well to use a dilution of 1 - 10,000. To make this dilution use two bottles of sterile water each containing 99 c. c. Shake the first dilution twenty-five times, then with a fresh sterile pipette transfer 1 e. c. to the second dilution water, rinsing the pipette to the mark as before ; this gives a dilution of 1 - 10,000. Shake the second dilution twenty-five times, then with a sterile pipette transfer 1 c. c. to the Petri dish, using care to raise the cover only as far as necessary to insert the end of the pipette. Take a tube of agar from the water bath, wipe the water from the outside of the tube with a piece of cloth, remove the plug, pass the mouth of the tube through the flame and pour the agar into the plate, using the same care as before to avoid exposure of the plate contents to the air. Carefully and thoroughly mix the agar and diluted milk in the Petri dish by a rotary motion, avoiding the formation of air bubbles or slopping of the agar, and after allowing the agar to harden for at least fifteen minutes at room temperature place the dish bottom down in the incubator. Controls. Plating should always be checked by controls. A blank plate should be made with each series of milk plates for control on the agar, water, air, Petri dishes, pipettes, etc. For control of the technique of plating, it is recommended that for work on "market milk" duplicate plates be made each day on several samples. "Certified milk" should always be plated in duplicate and where it is possible it is well to have one man's work occasionally checked by another. Unless duplicate plates show as a rule approximately the same count the worker should see if there is error in his technique. Plating should always be done in a place free from dust or currents of air. In order that colonies may have sufficient food for proper development 10 c. c. of agar shall be used for each plate. In plating a large number of samples at one time the dilution and transfer of diluted milk to the plated may be done for four or eight samples then the agar poured, one tube to each plate, then another eight samples diluted, etc. 514 BactkrioIvOgical Tests and Cultures INCUBATION AND COUNTING. Two standard temperatures are recognized : 1. 48 hour incubation at 37 degrees C. 2. Five day incubation at 21 degress C. Regulations governing the number of bacteria allowable in milk should direct the method to be used in examination and in all reports, papers, etc. on the bacterial count of milk this factor should be explicitly stated. Incubators should be carefullj^ regulated. Whatever tempera- ture of incubation may be used it is important that the incubator air sliould be saturated with moisture ; this may be accomplished by either having a depression in the floor of the incubator filled with water or by setting a pan of water on one of the shelves. Counting. Expressing of results. Since minor differences in milk counts are within the working error of methods and are of no significance in practice, the following scale has been adopted for recording- results of market milk examination : Counts below 50,000 are distinguished by five thousands. Counts between 50,000 and 100,000 are distinguished by ten thousands. Counts between 100,000 and 500,000 are distinguished by fifty thousands. Counts between 500,000 and 5.000,000 are distinguished by hundred thousands. Counts above 5,000,000 are distinguished by millions. Therefore only the following figures are used in reporting : 5,000 400,000 10,000 450,000 15,000 etc to 50,000 500,000 60,000 600,000 70,000 700,000 80,000 800,000 90,000 900,000 100,000 1,000,000 150,000 1,000,000 etc. to 5,000,000 200,000 6,000,000 250.000 7,000,000 ::;00,000 8,000,000 etc. by millions Microscopic Counts 515 Counts on "Certified" or "Inspected" milk shall be expressed as closely as the dilution factor will allow. The whole number of colonies on the plate shall be counted, the practice of counting a fractional part being resorted to only in case of necessity, such as partial spreading. Various counting devices have been recommended by diiferent workers. The more simple ones, where the whole plate can be seen at once, are more desirable on account of there being less likelihood of recounting colonies. Colonies too small to be seen with the naked eye or with slight magnification shall not be considered in the count. (B) MICROSCOPIC COUNT OF BACTERIA^ (BREED METHOD). Various methods for counting bacteria in milk by microscopic examination have been described, but the method that is com- monlj^ described as a direct microscopic exajnination of a dried film of milk has been found to be the simplest and most reliable method of counting the bacteria as they exist in the milk itself. It is recognized in this report as a standard or official technique of equal standing with the colony count from agar plates where used for judging the quality of unpasteurized milk. Apparatus required. In addition to a microscope, microscopic slides, stains, etc., the only special apparatus required is a capillary pipette which dis- charges 1/100 cc. of milk. The most satisfactory form of pipette is made from a straight piece of thick walled capillary tubing with a bore of such a size that the single graduation mark is from 1^ to 2^4 inches from the tip. The tip shall be blunt and of such a form that it will discharge the milk cleanly without running back on the side of the tip. Pipettes of this type are now listed by all of the usual supply houses. The pipettes shall be calibrated so as to deliver 1/100 cc, not to contain 1/100 cc. Because there are many inaccurately calibrated pipettes on the market, the calibra- tion of all pipettes shall be tested by weighing the amount of milk discharged on chemical balances. The weight for milk should be .0103 grams. Only a single pipette is needed in making a series of tests, provided this is kept clean while in use. In this kind of work cleanliness of glassware is more important than sterilization. 516 Bacterioi^ogicai. Tests and Cultures Clean towels may be used for wiping the exterior of the pipettes while making the microscopic preparations, and their bores may be kept clean by rinsing them in clean water between each sample. The small amount of water left in the bore may be rinsed out in the milk sample under examination. This method of procedure, while adding a small number of bacteria to each sample, intro- duces only a theoretical error, tests showing that such bacteria cannot subsequently be detected, and make no difference in the final result. After use, the pipettes should be kept in a glass- cleaning solution, such as the commonly used mixture of sulphuric acid and potassium bichromate. Routine laboratories will find it convenient to use larger microscopic slides than the ordinary 1 by 3 inch slide. The largest slides that have been found to be conveniently examined with the use of a mechanical stage are cut 2 by 4^/2 inches. Such slides may be stored in ordinary card catalogue cases and may be very cheaply prepared from thin window glass or old photo- graphic negatives. A margin of ground or etched glass on the longer edges of the slide about 34 ii^ch in width allows lead pencil labeling. The margins may be ground with an emery wheel, or they may be etched with hydroflouric acid. The cost of these home made slides ought to not to exceed 2 to 3 cents each, Avhereas the similar slides listed by supply houses cost much more than this, A special guide plate (size 2 by 4^/2 inches) marked off with 16 square centimeter areas is also needed. This can be obtained from regular supply houses. Only one of these is needed as it is used as a guide plate underneath the slides on which the milk preparations are made. Preparation of films of dried milk. After a thorough shaking of the sample, 0.01 cc, of milk or cream shall be deposited upon a clean glass slide by means of the pipette above described. Spread the drop of milk uniformly over an area of one square centimeter by means of a clean, stiff needle. This may be most conveniently done by placing the slide upon the guide plate just described, or upon any other form of guide plate of glass or paper which is ruled in square centimeter areas. The marks showing through the glass serve as guides. After spreading, the preparation shall be dried in a warm place upon a level surface protected from dust. In order to prevent notice- Microscope; Standardization 517 able growth, this drying must be accomplished within five to ten minutes ; but excessive heat must be avoided or the dr}^ films may crack and peel from the slide in later handling. After drying, the slides are to be dipped in xylol, or any other suitable fat solvent, for a sufficient time to remove the fat (at least one minute), then drained and again dried. After this, the slides are to be immersed in 90 per cent grain or denatured alcohol for one or more minutes, and then transferred to a fresh aqueous or carbolic acid solution of methylene blue (about 1 per cent, exact strength unimportant) that has previously been tested and found to stain the bacteria satisfactorily in milk prepar- ations. Some methylene blue now on the market in powder form is very unsatisfactory in that solutions will dissolve the milk films, or will wash them with an even blue color in which the bacteria fail to show distinctly. Old or unfiltered stains are to be avoided as they may contain troublesome precipitates. The slides are to be left in the stain until overstained. They are then to be rinsed in water and decolorized in alcohol. The decolorization takes from several seconds to a minute or more, during which time the slide should be under observation, in order that the decolorization may not proceed too far. When properly decolorized the background of the film should show a faint blue tint. Poorly stained slides may be decolorized and stained with- out apparent injur3^ After drying, the slides may be examined at once, or they may be preserved indefinitely. Standardization of the microscope. The microscope used must be so adjusted that each field covers a certain known fraction of the area of a square centimeter. This adjustment is simple if a micrometer slide, ruled in hundreths of a millimeter, is at hand (sometimes called a stage micrometer as it is used under the objective on the stage of the microscope). The microscope should have a 1.9 mm. (1/12 inch) oil immersion lens, and an ocular giving approximately the field desired (for example a 6.4 x ocular). It sould also be fitted with a mechanical stage. If the large slides described above are used, this must be a special stage allowing a larger area of the slide to be examined than can be examined with the usual mechanical stage. To standardize the microscope, place the stage micrometer on the stage of the microscope, and by selection of oculars or by 518 Bacteriological Tests and Cultures adjustment of the draw tube, or both, bring the diameter of the whole microscopic tield to .205 mm. When so adjusted, each field of the microscope covers an area of approximately 1/3000 cm. (actually 1/3028 cm). This means that the dried milk solids from 1/300,000 part of a cc. of milk are visible in each field of the microscope. Therefore if the bacteria in one field only are counted, the number found should be multiplied by 300^,000 to give the estimated number of bacteria per cc. In practice, how- ever, more than a single field is examined so that the number used for multiplication is smaller than this. As the microscopic examinations must be made with greater care where the bacteria are relatively few in number, it is required that, in grading low count milk, a special ocular micrometer with a circular ruling divided into quadrants shall be used. In using this micrometer, the microscope shall be so adjusted that the dia- meter of the circle on the eye piece micrometer shall be .146 mm. In this case the amount of dried milk solids examined in eacli field of the microscope is 1/600,000 part of a cc. of milk. The limitation of the examination of the slide to the central portion of each field, avoids using the margins of the field where definition is hazy, and lessens the danger of overlooking bacteria. Like- wise the magnification used is greater than that used where the whole field is examined. Counting and Grading' Milk. The number of fields of the microscope to be examined varies Avith the character of the milk, and with the character of the data desired. Experience has shown that where the purpose is primar- ily to detect and eliminate the worst milk from ordinary market milk supplies, it is entirely permissible to use the entire field of the microscope for examination. At least thirty representative fields of the microscope should be examined for each sample of milk. Wliere the average number of individual bacteria (not groups of bacteria) is less than one per field, it may be assumed that the milk will ordinarily give an official plate count of less than 60,000 per cc. Where the number is less than 100 in 30 fields (average of less than 3 1/3 bacteria per field) it may be assumed that the official plate count will be less than 200,000 per cc. Where less than 1000 per 30 fields (average of less than 33 1/3 Standards 519 per field) is may be assumed that the official plate count will not exceed one to two million per cc. Where counts are made in order to enforce stringent standards, as at Grade A plants^^' or as a basis for premiums on milk giving an official plate count of less than 10,000 per cc, the special eye- piece micrometer described above shall be used and the micro- scope so adjusted that only the central portion of each field is examined for counting. Where less than 5 bacteria are found in 60 fields (average of less than 1/12 of a bacterium per field) it may be assumed that the milk would ordinarily give an official plate count of less than 10,000 per cc. The grading of milk of tills type must be done with especial care as persons inexperienced with microscopic work have been found readily to confuse ex- traneous objects with bacteria, in milk containing very few organisms. Where the number is less than 30 per 60 field (average of less than ^/^ a bacterium per field), it may be assumed that the official plate count will be less than 60,000 per cc. Where the number is less than 100 per 60 fields (average of less than 1% bacteria per field), it may be assumed that the official plate count will be less than 200,000 per cc. Where the number is less than 1,000 per 60 fields (average of less than 16% bacteria per field), it may be assumed that the official plate count will be less than one to two million. The standards given are computed (with the exception of the poorest grades) on the assumption that the official plate count will be normally average 1/5 of the total number of individual bacteria present. As many cases Avill be found which diverge markedly from the average, it is self evident that this average represents only an approximation to the real conditions in any specific case so that in some cases the microscopic grading will be more severe than that based on the plate counts, and vice versa. There is still a lack of sufficient data from which to judge fairly which system of grading is the more accurate. The indications are, however, that where the work is done with equal skill and care, and the allowances indicated are made, a reasonably close agreement in grade will be secured^ ^. This fact is highly reassur- ing as to the general accuracy of both systems of grading. In the routine grading of milk by the microscopic method it is not expected that exact counts will be made. A high grade 520 Bactrrioi^ogical Tests and Cultures milk will show field after field of the microscope in which no bacteria are seen, while a poor grade of milk will show numerous bacteria in every field examined. It is only where the number of bacteria present is close to the border line between grades that counts need to be made. The examination, however, must be sufficiently thorough to make sure of the grade as specified above. In order to ensure careful work in grading, it is required that laboratories conforming to standard procedure shall preserve microscopic preparations until a reasonable period has elapsed after the reports are rendered to the person or persons whose milk has been examined. It is an excellent custom occasionally to have the grading done by one analyst repeated by a second analyst, particularly in those cases where punitive actions are to be based on the reports made. Common Sources of Error in Count. Routine microscopic counts, like all bacterial counts, are to be regarded as estimates of numbers only. They cannot be made with absolute accuracy even with the most careful technique. Errors will arise from inaccuracies in measurement of the minute quantities of milk examined at any one time, from faulty staining or preparation of slides, from mistakes in observation and the like. These limitations, while important, are not difficult to overcome in sufficient measure to make microscopic grading a satisfactory method of controlling the quality of unpasteurized milk. As it is oidy in this way that counts of the bacteria themselves can be made, it must be recognized that accurately carried out micro- scopic counts of individual bacteria give the truest picture of the actual conditions of raw milk that can be obtained with any technique. Where there is reason to fear the presence of large numbers of dead organisms, as for example in pasteurized milk, it is improper to place reliance upon microscopic counts. Valuable information may, however, sometimes be obtained by making both plate and microscopic counts from samples of pasteurized milk. Reports. As only a few ordinances^" have yet been adopted in which both official and microscopic count standards have been given. Vkrification MiiTHODS 521 the form of report used will need to be adapted to the circum- stances under which each laboratory is working. Specific counts should not be given under normal circumstances, and care should be taken to avoid making finer distinctions in grade than are justified by the accuracy of the grading. A series of samples should be examined in all cases before rendering judgment as as to the quality of any milk supply. VERIFICATION AND RESEARCH METHODS. Because of the fact that the Committee on Technique of the Society of American Bacteriologists has undertaken the study of methods of making bacterial counts for research purposes, it is not necessary to discuss further the use of standard methods as research methods. The standard methods are designed for use in routine analytical work and should also be used in those cases where investigations involving routine milk control are under consideration. They may also be suitable for use in other cases, but ordinarily will not be found to give the grade of accuracy expected in research work. There is in all routine laboratories a very important use for methods giving more accurate data than can be obtained from the use of the routine count. These may be termed verification methods ; and they should be used in all cases where administra- tive actions are taken which depend upon the analytical results^^. The simplest form of verification for official plate count in the case of raw milk is to make a count from the same sample of milk by direct microscopic examination, and vice versa. If the counts found from the second examination are such that they are readily understandable under the known conditions, a very large part of the uncertainty existing in regard to the first count is eliminated at once. Under other conditions it may be found advantageous to verify the routine plate counts by making plate counts in which additional dilutions, or plates are used. Likewise more careful microscopic counts may be obtained either by examining dupli- cate preparations from the same sample of milk, or by making a more careful examination of the original preparation than that made for routine purposes. If procedures of this sort were more common in bacteriological laboratories, control officials would have much firmer ground upon which to defend their actions in court if necessary. 522 BACTERioLor.icAL Tests and Cultures DETECTION OF SPECIFIC PATHOGENS IN MILK. There is no part of the field of sanitary analysis of milk where routine laboratory methods have so failed to meet the need of the control official as at this point. Some notable attempts have been made to secure the elimination of the bacillus of bovine tuber- culosis from market milk supplies through routine laboratory examinations of milk samples ; but none have been found to be sufficiently practical to have been widely followed. Other pathogenic organisms, such as those of typhoid fever, are rarely sought for in milk, though methods for detecting this organism have been suggested." In all of these cases, it has become necessary to rely on elimination of the pathogens in market milk supplies through pasteurization, or by veterinary inspection of the herds, and medical supervision of dairy employees. Several of our important control laboratories are, however, using a laboratory method for the elimination of long chain streptococci derived from inflamed udders. Certain precautions must, however, be used in this case as false interpretations of findings are easily possible. The long chain streptococci are readily found by microscopic examination of dried films of milk or sediments from centrifuged samples of milk. Perhaps the two most frequently used routine methods are the Breed method already described, and the Stewart-Slack method described in detail in the first edition issued by the American Public Health Association. The use of these methods for this purpose lias shown that even the presence of large numbers of long chain streptococci may be of little significance where there has been opportunity for their groAvth after the milk has been drawn. Streptococci of the long chain type occur frequently in apparently normal udders, and may even occur in very large numbers where there is no clinical evidence of inflammation.-" Nevertheless, where samples of milk can be taken from individual cans as delivered within 6 hours after milking, it has been found that it is almost invar- iably possible to find a cow sufifering from an inflamed udder if the count of individual cocci in long chains is in excess of 1,000,- 000 per cc. Such milk usually contains leucocytes in excess of 1,000,000 per cc. ; but this relationship is not an invariable one. Because of the presence of alkaline substances from blood serum, Comme;rciai, Application 523 milk from cows with inflamed udders usually has a pH value greater than 6.8 and may also contain detectable mucin fibers.-^ Where milk is centrifuged and the sediment examined, even greater caution should be used in drawing conclusions, as the concentration of material may cause insignificant numbers of these organisms to be regarded as significant. In this connection it should be remembered that many entirely satisfactory butter starters are composed of streptococci which occur in fairly long- chains. These supposedly saphrophytic streptococci cannot be distinguished from the udder streptococci through microscopic examination alone. Under these conditions, the laboratory findings should in every case be confirmed by clinical examination of suspected herds before action is taken. COMMERCIAL APPLICATIONS OF BACTERIA TO DAIRY PRODUCTS. Preliminary. As already pointed out several types of bacteria find a most useful application in several branches of the dairy industry. The products in which they play a useful role are of great commercial and economic importance, and include butter, cheese and cultured buttermilk as the best representatives in the list. The product carrying the bacteria is known as the culture or the starter. In this chapter the term culture will be used. STRAIN OF BACTERIA RECOMMENDED. In the experiments reported in this chapter, the bacteria used was a strain of Streptococcus Lacticus Kruse described upon page 491. This is illustrated under Fig. 118, The culture has been propagated continuously for about four and one half years under ideal conditions so that as a result of this intensive breed- ing, all undesirable properties had been bred out, and the culture was one of unusual virility which yielded in practice products of most desirable flavor and keeping qualities. Under similar con- ditions, the same favorable results can be duplicated in any dairy plant. TEMPERATURE TO USE IN RIPENING. It is practically universally agreed that the best temperature for the propagation of Streptococcus Lacticus of the strain used 524 Bactrriologicai. Tksts and Cultures in cultures employed in the dairy industry is 20^ C. (68° F.) The control of temperature during the propagation period is of vast influence upon the resulting culture. Cultures of the Bulgaricus type have an optimum temperature of growth of 37" C (98.6° F.). The use of this type is greatly upon the decline, and is but little used in commercial work. Fig. 118. Streptococcus Lacticus. Fhotomicrograpli from Research labora- tories, Telling--Bene Vernon Co. Magnified 950 Diameters. Isolated from Cultured Buttermilk. FACTORS RELATING TO THE GROWTH OF CULTURES IN DAIRY PRODUCTS. Several investigators have shown that the rate of growth of the organisms in a culture varies during different periods or phases of its life. By its life is meant a condition of environment in which the culture is permitted to grow without any unfavor- able interference. Buchanan^- divides the life cycle of a culture into given phases, each phase having a different rate of growth per organism than the phase next preceding it as follows : (1), The initial stationary phase. During this phase the bac- teria remain constant or nearly so. (2). The lag or positive growth acceleration phase. During this phase the average rate of growth per organism increases with the time. Reaction of Acid 525 (3). The logarithmic growth phase. The rate of growth per organism in this period is constant. The organisms are dividing regularily, and the number of organisms are increasing in a geometric ratio. (4). The phase of negative growth acceleration. The average rate of growth per organism decreases during this period. (5). The maximum stationary phase. There is little or no increase or decrease in the number of organisms during this period. (6). The phase of accelerated death. The number of bac- teria decreases slowly at first, but the rate of death per organism gradually increases until it reaches a maximum. (7.) The logarithmic death phase. During this phase, the rate of death per organism is constant. Barber-^ observed that the age of the culture influenced the lag phase. He found that if a sub-culture was made in the same medium during the logarithmic period, this sub-culture does not go through a lag period, but continues to grow, at the same rate per organism as the parent culture. If the sub-culture is made after the logarithmic period there is a distinct lag period. These observations were confirmed by Penfold and by Ches- ney.-* RELATION OF ACID, DEVELOPMENT AND TIME OF RIPENING. Frohring-' conducted a series of careful experiments with a strain of Bacillus Streptococcus Lacticus using the 'development of the lactic acid in the culture as the criterion of the growth of the organisms. This method was selected because of the con- siderable errors that may result when counting bacteria by the plate method. Another important reason for this choice was the desirability of obtaining exact data regarding the relation be- tween time and acidity in culture growth. Frohring points out that this method of study gives a fairly good conception of the first four growth phases mentioned above, but that it is valueless in determining the last three. The results obtained by Frohring are given in Fig. 119. As the results in Fig. 119 indicate, the acid development is not in direct proportion to the time, as is commonly believed to be the case by many accustomed to using cviltures. The results 526 Bacteriologicai, Tests and Cultures are typical of the acid development curve produced by a fresh vigorous culture which is being propagated daily under optimum conditions which are under exact control. 15 cc. of this culture was added to 750 cc. of the media. Figr. 119. The Belation Between Time of Incubation and Acid Development in the Growth of Culture. As shown in the graph, there is scarcely any increase in acidity during the first four hours. From the fourth to the tenth hour, the increase is a gradual one. In this particular experiment coagulation started at the tenth hour, with a total acidity of .64 per cent and from that point the growth was very much retarded, but it continued to increase until the ripening had continued for seventeen and a half hours, at which point it became constant with a total acid content of 1.00 per cent, being still of thi^i acidity at the end of 74 hours. INFLUENCE OF QUANTITY OF CULTURE ADDED TO MEDIA. In another series of experiments Frohring studied the influ- ence of the addition of varying quantities of culture to a given media. The cultures were fresh, vigorous ones, similar to those employed in the previous experiment, and these were added to a Quantity of Culture 527 good quality of pasteurized skim-milk. The results obtained are given in Table 93. TABLE 93. Influence of Quantity of Culture Added to Media. Acidity Gi/en Is That Developed in Addition to Initial Acidity, and Acid Added in Starter. Experi ment No. Quantit}' o culture add- ed to 750 c c. of media Per cent of lactic acid in media p end of 15 hours. Experi- ment No Quantity o 1 cxilture add- ed to 7.50 (• c. uf media. Per cent of lactic acid in media at end of 1 hours. 5 c. c. 10 c. c. 20 c. c. 30 c. c. 40 c. c. .89 .91 .92 .93 5 c. c. 10 c. c. 20 c. c. 30 c. c. 40 c. c. .94 .90 .94 .99 .97 .70f .605 I .xos Aeld isYslopeii urtnr IJ nour« Inoubatlon (at iO»C) In adaiUon to Ir.ltUi acUSty a-M icH adlod ir sta Amount of culture aiaad (C.:.) ic 15 20 30 io 50 5 *o 15- 20 30 40 50 5 10 15 ;o 30 40 50 *^- "»■ 3 m, Tig. 120. Influence of Quantity of Culture Used Upon Acid Development in Media. The results of another series of experiments by Frohring are given in the graph under Fig. 120. 528 Bacteriological Tests and Cultures The results of the preceding experiments by Frohring indicate that the amount of culture added is not so important as the grow- ing condition of the organisms that are introduced, and their ability to divide, and go through the logarithmic stage of growth after a few hours of incubation. The determining factor in judg- ing the value of a culture is not the total number of organisms contained, but rather the number of organisms capable of prop- erly reproducing themselves. He has applied this knowledge in practice with marked success. ututi •we ^ 4» 0.0. .ao ■ __„-.,r«-^ :::ri WO. 0. ^^,-*— -^ " -t——^"P^ >? .70 ^.y"""^ y"' . 2 / *' i S' .60 / y i / ^' ; 1 .10 ,*0 _y^ .-" Hours ol inCiJbatiua % 2 i 4 ^ 6 7 8 9 . M J^ W i W M IS »6 ■ ' j ^ 1 — -l Pig-, 121. Increase in Titratable Acidity Using- 15 c.c. and 40 c.c. of Culture to 750 c.c. of Media. In the above figure it is shown that the same results are obtained at the end of the ripening period when only 15 cc. (About 2.0 per cent), or when 40 cc. (about 5.0 per cent) of culture are added to the media. In the manufacture of cultured buttermilk, cottage cheese, cheddar cheese, soft cheeses, margarine and butter made from ripened cream, or where the culture is worked directly into the butter, it is universally conceded that the quality and uniformity from day to day of the culture is of the greatest importance to the manufacturer who is endeavoring, to maintain a uniform product. A careful study of culture propagation reveals a great many factors which, when properly controlled, will insure the successful Time and TiiMPHRATuRe "529 propagation of a uniform culture free from contamination. Under ordinary factory conditions, painstaking care may eliminate some of the variables. There still remains, however, many vari- ables over which the operator has no control. This means a constant risk, or hazard of meeting unfavorable conditions, and as a consequence, frequent off flavored or inferior products. TIME OF RIPENING. Frohring has proved that if too much time is taken for the ripening period, undesirable types of bacteria may gain the ascendency'- before the logarithmic stage of growth is reached, and as a result bad favors may appear in the finished product. This condition may exist if too small an amount of culture is added to the media. Upon the other hand, if the ripening time is too short, due to the addition of an excessive amount of culture, the results are also not satisfactory. In general, it can be stated that the least amount of culture should be added to produce a satisfactory product. No more acid should be added mechanically than necessary. The most practi- cal ripening; time is 14 hours. EFFECT OF HOLDING CULTURE AT VARIOUS TEMPERATURES. In handling cultures it is important to know the influence of the holding temperature upon tlie growing qualities of the culture. This is the determining factor in establishing the frequency of repropagation. This was carefully studied by Frohring, under four different temperature conditions. In one experiment the mother culture was frozen ; in a second experiment it was kept in ice water; in a third experiment it was kept at 45° F., and in a fourth experiment at 68° F. Inoculations from each of the above mother cultures were made in pasteurized skim-milk media upon successive days as indicated. In each test 15 cc. of the four respective cultures were inoculated into 750 cc. of skim-milk, and these sub-culture were incubated for 15^^ hours at 68° F. The titratable acidity was determined at the end of each incuba- 530 Bacteriological Tests and Cultures tion period, and this was used as the criterion of the growing qualities of the respective cultures. The results in the following chart show plainly how the grow- ing qualities of a culture are influenced by the temperature at which it is kept following the end of the incubation period. The culture that was frozen lost little of its reproductive powers up to eight days. After that it deteriorated rapidly, and at the end of eleven days it had practically lost its ability to grow. The fol- lowing table gives the main conclusions that can be derived from this experiment. ACIDITY OF SUBCULTURE OBTAINED FROM MOTHER CULTURE, THE L/\TTER BEING KEPT AT TEMPERATURES INDICATED DURING EXPERIMENT. HOURS OF INCUBATION-Isi HOURS AT eb'F AMOUNT OF CULTURE ADDED- IS CC. TO 750 CO. 6KIM-MILK TIME IN PAYS Tig. 122. Influence of Holding Temperatures of Cultures Upon the Growing Qualities of the Same. Apparatus for Propagating Culturks 531 TABLE 94. Summary of Experiment to Deteimine Influence of Holding Temperature Upon the Growing Qualities of Cultures. T e m p e rature at which cultures were held. Number of days held at tempera- tures indicated before growing qualities began to deteriorate. Number of days held at tempera- tures indicated when cultures had pi-actically lost their ability to grow. Number of days during which cultures can be kept at temper- atures indicated before requiring repropagation of culture. Frozen 8 12 5 Ice water, 32° F. . 11 15 7 45° F.. 7 8 2 68 F°.. 2 7 1 The results given in the above described experiment show plainl}^ the great influence of holding temperature upon the grow- ing qualities of cultures. The best results are obtained where the cultures are kept in ice water. In practice even when the cultures are kept in ice water, a limit of one week should not be exceeded, before repropagating the culture. When held between 32 and 45° F. the limit should not exceed two days. At temperatures above 45° F. the deterioration of the culture is so rapid, as to render such temperatures impractical for holding purposes. APPARATUS DESIGNED TO PROPAGATE PURE CULTURES. To W. 0. Frohring, Director of Laboratories of the Telling- Belle Vernon Co., belongs the credit for the origin and develop- ment of the Mojonnier Culture Controller. The principles under- lying the construction and operation of this apparatus were established by him in a large plant devoted to the manufacture of numerous dairy products requiring the use of pure cultures, the principal being commercial buttermilk, cottage cheese and butter. The Mojonnier Culture Controller illustrated under Fig. 123 places the propagation of pure cultures upon a scientific basis. It is a highly specialized apparatus by means of which all variables are eliminated. It makes the propagation of the culture a 532 Bacteriological Tlsts and Cultures definite and a simple operation. It eliminates the necessity of obtaining cultures from outside sources. Its great advantage is the fact that it insures a uniform culture from day to day. This in turn is reflected in the uniformity of the finished product, since a good culture is the starting point of a good finished product. Pig-. 123. Mojonnier Culture Controller, Model "B" DESCRIPTION OF MOJONNIER CULTURE CONTROLLER. It consists of two chambers. The chamber to the right is intended to hold a sufficient supply of ice to maintain a tempera- ture of 68° F. in the other chamber, over a considerable period of time. Or it is also furnished so that it can be used inter- changeably for ice, or for circulating brine through the lead coils placed in the chamber. Either method works out satisfactorily in practice, and the choice is governed by the conditions prevail- The MojoNNiER Culture Controller 533 ing at the plant where the apparatus is to be used. The ice chamber also frequently serves as a refrigerator for holding the cultures after the same have been incubated. Tig. 124. Cross Section, Mojonnier Culture Controller. A — Incubator Chamber. B — Refrigerator Chamber. C — Relay and Pan Motor Housing. With electro-thermostatic control showing- cross section of the two com- partments. The arrows indicate complete circulation of air in the chambers. The relay cabinet on side insures positive and continuous control of tempera- tures in the incubation chambers. The chamber to the left is the incubating chamber. It can be used for the propagation of both Bacillus Lacticus which is incubated at 68° F., and of Bacillus Bulgaricus which is incubated at 98.6^ F. When desired to change from one culture to the other, all that is necessary is to change the thermostat inside the chamber using the one that gives the proper temperature control. The incubating chamber is provided with a fan oper- ated by means of a motor, thus insuring uniform temperature in all parts of the chamber. It is fitted with heating elements of the proper design. Ports fitted with shutters connecting with the ice chamber makes possible the necessary air circulation. The temperature control is based upon the use of a mercury thermo- 534 Bacteriological Tests and Cultures stat operating with special design of relay. Only 1/100 of an ampere passes through the thermostat thus eliminating all oxida- tion at points of contact. The operation is entirely automatic. The ice chamber has a capacity of about 400 pounds of ice. The incubating chamber has a capacity of 54 quarts or bottles or 125^ gallons of milk, in one model, and 17 quarts or 41^ gallons in another model. STERILIZER USED IN CONNECTION WITH THE MOJONNIER CULTURE CONTROLLER. The sterilizer that was especially designed for use in connection with the Mojon- nier Culture Controller is illustrated under Fig. 125. The quart culture jars can be both heated and cooled to the proper temperatures in it, and the entire design and arrangement is such as to facilitate this important op- •. eration. How to propagate cultures using the Mojonnier Culture Controller. rig-. 125. SterUizer Recommended to Be The SUCCeSSlVC StcpS in the Used in Connection with the Mojonnier propagation of pure Cultures Culture Controller. need to be well understood, and the details of each step closely followed from day to day no matter how trivial the same may seem, otherwise satisfactory results cannot be obtained. The kind of media to use. Although the pure culture organisms will grow in a variety of different mediums, such as nutrient broth, gelatin, etc., the preponderance of evidence is in favor of the use of skim-milk of first class quality. Whole milk is the next best, but should not Preparation of AIedia 535 be used if skim-milk is obtainable. If whole milk is to be used, remove as much cream as possible by the gravity method. Skim- milk produced by centrifugal or gravity methods, — the former method of course, being preferable. It is needless to say that this should be as fresh as possible, and of the best quality obtain- able. It is desirable that as little change as possible should have taken place in the milk, not on account of any danger from the organisms present, as the media is subsequently pasteurized, but on account of undesirable by-products that may be present vs^here change has occurred as a result of chemical action wrought by bacteria differing from pure culture varieties. It is possible to have such chemical changes take place in milk which may later tend to have an inhibiting effect upon the growth of the Bacillus Lacticus organisms. The use of skim-milk of good quality, promptly sterilized, will eliminate the above factor. STERILIZATION AND PREPARATION OF MEDIA. Probably the most common method of sterilization in labora- tories is by means of steam pressure of 15 to 20 pounds for fifteen minutes to one half hour, in an autoclave. This method is a quick and positive means of sterilization, however, it has a decided disadvantage as a method of sterilizing milk used in propagating cultures. It is practically impossible to sterilize under pressure without causing an appreciable change in the milk. The most important change is probably in the )milk sugar, which is caramelized more or less by the high temperatvire used during sterilization. In the metabolism of the bacteria during the process of growth, some of the milk sugar is changed to lactic acid. It would seem reasonable to conclude that any decided change in the milk sugar would be undesirable. This proves in actual practice to be the case, and can be easily demonstrated. At the same time a change takes place in the casein. This is not definitely understood at present, but all the evidence is in favor of the view that certain chemical changes take place in the casein molecule. While this is probably not so important from the standpoint of food material of the bacteria, yet it is very undesirable as it makes it next to impossible to judge accurately the degree of ripening by the extent to which the milk is curdled. Two possible explanations of the chemical 536 BacterioIvOGical Tf:sts and Cultures changes in casein due to heating are advanced. One theory is that part of the calcium is split off from the casein molecule. An- other theory is that the casein is partly dehydrated. The more change that has taken place in the casein the less it will be curdled, by the same amount of acid. A culture may thus be over ripe, and at the same time not set in a good firm curd. Due to these physical changes, the end point in ripening may be easily misjudged. Overheating of the milk .probably causes changes in the mineral salts, and it exerts an unfavorable effect upon water soluble C vitamine, all of which may have some possible bearing upon culture development. By means of intermittent sterilization, the milk is heated to a temperature above 212° F. Heating for one hour at 212° F. will destroy almost all organisms, except the spore formers. By allowing the milk to incubate between the heatings, the spores are given a chance to vegetate, and by the end of the heating on the third day they are nearly all destroyed, being caught while in the vegetative or non-resistant state. This method of steriliza- tion has not the disadvantage of the one previously mentioned, and the heat may be applied uniformly. However, it has the disadvantage in time, and is not very practical for this purpose. Where the milk used as media is of first class quality, it will be found that heating to 170" F. for one and one half hours in the sterilizer described under Fig. 125, will be sufficient to insure good results. At the end of the heating period, cold water is to be turned into the sterilizer to displace the hot water, and the milk in the jars cooled as promptly as possible to about 68° F. It must be remembered that this cannot be called sterilization but rather high temperature pasteurization, and the results may not be an absolutely sterile media. However, where the milk is of first class quality the organisms left will be insignificant numeri- cally, and of a type that will cause no trouble in the culture if it is inoculated the same day. CULTURE JARS USED— HOW TREATED. Several types of culture jars can be successfully used. In some cases pint size or quart size milk bottles, sealed with a paper cap, are very successfully employed. Experience has proved that culture jars such as illustrated under Fig. 126 are Prockdurr 537 the most satisfactory to use. Both the jars and the covers can be successfully sterilized by inverting the same in the sterilizer described in this chapter (See Fig. 125) and heating with flow- ing steam. To seal the jars, parchment paper is placed between the lid and the jar. This paper can itself be sterilized by dipping it in hot paraffine, grain aleoliol, or sodium hypochlorite. FILLING THE JARS \YITH SKIM-MILK. After the jars illustrated under Fig 126 are thoroughly cleansed and sterilized they are weighed upon a balance, and for the quart size. 750 grams of the sterilized skim-milk are added to each jar from the metal percolator suspended Tig. 126. Type of above the balance. This is done with all the jars. Jars for Culture pj^^^ ^^j^^ -^ ^^^ ^^^^^^ where Only a fcw cultures Propagation. '' "^ are made daily, and they may also be used for the culture held over to propagate the next day's culture. Measuring may be done by volume if more convenient. The essential thing is to use a definite amount every day. Half gallon glass jars can frequently be used to good advantage. SEALING THE JARS. The method of sealing must accomplish the following results: (1). It must eliminate the possibility of bacteria getting into the milk after it is sterilized. (2). At the same time, it should not be so the air cannot expand without breaking the bottle while sterilizing, or form a vacuum when cooled. (3). It must protect a sterilized lip surface over which the culture is poured when emptying. (4). It must protect the lip surface while handling. (5). It must be air and water tight after inoculating. (6). It must pi'otect against molds. All the^e things are accomplished by using the glass jars illustrated above. The method of sealing is as follows : 538 Bacterioi^ogicaIv Tests and Cur.TuRE:s The jars with the covers must be first thoroughly cleaned and sterilized in an inverted position in the sterilizer using just enough steam pressure to insure circulation, and kept in this posi- tion until ready for use. After the proper amount of milk is weighed or measured into the jars, two circles of parchment paper previously sterilized, are placed over the jar opening, and the cover then placed in position and loosely clamped in place. STERILIZING OR HIGHLY PASTEURIZING THE MILK. Without further delay the jars of milk are placed in the sterilizer, and heated for one to one and a half hours at 170° F. using preferably, flowing steam. This has the advantage of heating the jars rapidly, and of reaching with the heat, all parts of the joint between the lid and the jar. However, it is usually equally satisfactory to use hot water of the temperature indicated, instead of flowing steam. At the end of the heating period the cold water valve is opened, and the jars with their contents are rapidly cooled to 68° F. without removing from the sterilizer. The media in the jars is now ready to inoculate. The inoculation should be done promptly, and before the media has undegone a change in temperature. The method to use in inoculating the media immediately follows. PREPARATION OF CULTURE PIPETTES. These pipettes are especially designed with bulb for holding cotton, and they are of 10 cc. capacity graduated to 1 cc. all being as illustrated under Fig. 127. The top, which is placed in the mouth, should be plugged (not too tightly) with the non- absorbent cotton. This cotton is for the purpose of preventing the possibility of contamination of the culture from the mouth, or saliva getting into the pipette. After the pipettes are thoroughly cleaned and the cotton plug is inserted near the upper end, they are wrapped in ordinary cheap wrapping paper, using just enough to cover them, and fastened by twisting the end. While tlius wrapped, they should be sterilized either under steam pressure of 15 pounds for 15 minutes, or they may be steamed in the sterilizer under low pressure using streaming steam. They are kept wrapped after sterilizing and. until ready to use. Amount of CuvruRE: 539 HOW TO DETERMINE THE PROPER AMOUNT OF CULTURE TO ADD FOR A GIVEN LENGTH OF TIME OF INCUBATION. 1 TO BE I PLUGGED >, NON-ABSORBENT COTTON THEN STERILIZED When starting out to use the Mojonnier Culture Controller, it is necessary to determine the amount of culture to be added in order to have the new culture ripened to the proper degree in a given length of time. This time should not be over 15 hours nor less than 8 hours. Prepare six quart jars containing 750 grams each of sterilized milk. After sterilizing, cooling and adjusting the temperature at 68° F., hold them at that temperature in the incubator until the regular time for propagating the cultures. This should not exceed one hour. At that time, to No. 1, add 3.75 grams of culture from the pipette ; to No. 2, 10 grams ; to No. 3, 15 grams ; to No. 4, 20 grams; to No. 5, 25 grams, and to No. 6, 30 grams. The bottles are then resealed. They are shaken up thoroughly, and placed in the incu- bator, and left until the time convenient to take them out every day. At this time they should be removed from the incubator, — carefully, so as not to break the curd, and examined. The proper amount of culture to use every day is the quantity placed in the bottle in which the milk is curdled with a rather tirm, jelly-like consistency without showing traces of whey on the top. This proportion should then be used and continued, unless the culture increases in strength, in which case the amount is reduced in proportion. In this connection, it must be remembered, that, although the amount of culture may be changed to take care of the ripening in the desired length of time, the temperature at which the culture is incubated must never be changed. This, of course, means the cul- tures of the same type, for the Bulgaricus type requires a higher temperature as Avill be explained later. Ordinarily this will be sufficient range to find the proper amount for ordinary cultures where the incubating time is about 14 hours. A culture of ordinary strength should require the addition of about 15 grams to 750 grams of sterile milk in order to coagulate Pig-. 127. Pipette for Measuringr Cultures Into Media. 540 Bacteriological Tests and Cultures or ripen the new culture properly in 14 hours. If less than these amounts are found to be sufficient it will indicate that the culture is possibly a little stronger, or more active than ordinarily. Of course, if it is necessary to add more than this amount, it will indi- cate that the culture is not as vigorous as the average. After the right proportion has been established, the same time and amounts should be used regularly. In this way, an increase or decrease in the activity of the culture can be quickly noted. It has been found that wherever practical the 12-14 hour incubation using 15 grams of culture to 750 grams of milk gives the most satis- factory control. If the culture is of a good type, it Avill gradually tend to increase in strength or activity, and a decrease would indicate that it is either an undesirable strain of Bacillus Lacticus. or there is some mistake being made in the method of handling. Prohring has proved that when cultures are given improper environment, they may have sufficient life and vigor to reach the curdling point of milk, but not sufficient to pass through the logarithmic phase of growth. Be sure to see that the ice con- tainer is filled with cracked ice each time, and that the ther- mometer in the incubator shows that the temperature control is working properly. From the relation established by the trial propagation described above, it is also possible to arrive at the proper amount of starter to add to the big starter can, or to the finished product to be ripened. Since the temperature in these subsequent operations is generally not under as exact control as in the culture controller, a slight diflPerence in the relation may be noted. However, this may easily be determined by observation of the first ripening. FINAL SEALING OF CULTURE JARS. After the proper amounts of culture has been added to the jars of milk to be incubated, the parchment paper and the glass top are replaced upon the jars, care being taken that the milk in the jar does not become contaminated. The jars are then tightly sealed, and the tops of the same properly dated. INCUBATION. After tlie final sealing, it is very important that each jar be well shaken to mix the culture with media. The jars are then COOI.ING THE Culture 541 placed in the incubator which is kept in operation at 68° F. The ice container should be filled with block ice ; the door on the refrigerating chamber closed tightly; the shutter between it and the incubating chamber should be opened to the proper degree, and the fan in the incubating chamber set in operation. The jars should not be disturbed, or the incubator door opened until the time of incubation has passed, which is usually 12 to 14 hours. COOLING. After removing the jars containing the culture from the incubator, — being careful not to break the curd, they should be quickly cooled by placing in the sterilizer to which has been added water containing a generous amount of ice. They must be kept in ice water but not frozen, until ready for use. A culture may be all right to use after being in ice water for as long as one week, and sometimes even longer, but the best results are obtained when the cultures are used within 48 hours of ripening. The cultures to be used in re-propagating should be given special attention, and as a rule should be reinoculated at least every other day. They should be stored in ice water. When the desired length of time has intervened for incubation, the milk should be found coagulated to about the consistency of jelly, without the presence of anj^ whey. The whey indicates over ripeness which if continued will weaken the culture. Overripening of the culture is undesirable since the culture is carried through the phase following the logarithmic phase, after Avhich the culture may reach the phase of accelerated death in Avhich the organisms die off very rapidly. The appearancei occasionally of a small amount of whey on one or two cultures should not indicate that the ones having this whey are not all fit to use. however, if this continues, either the time of incubation should be shortened or the amount of culture added decreased, preferably the latter. The best way is to run another trial batch as described above, using the same time of incubation, and vary- ing the amount of culture added to each of the trial jars. At no time should the culture show the presence of gas forming organ- isms which is indicated by the presence of bubbles or "pin heads" in the curd. When ready to inoculate again, the cultures kept for this purpose are taken from the ice water carefully wiped dry with 542 Bacteriological Tests and Cultures a clean cloth, and the same precedure carried out with the exception of course, of the trial incubation. It is always a good plan to have one extra culture which may be left in the ice container in case of an accident to the growing culture such as the power being turned off, and the temperature going down too low for ripening. The propagation of B. Bulgaricus is conducted the same as described above, excepting that the thermostat in the incubating chamber is changed from 68 to 98.6° F, A BRIEF SUMMARY OF DIRECTIONS FOR OPERATING THE MOJONNIER CULTURE CONTROLLER. (1). Jars to be thoroughly cleaned and steamed. (2). Secure best fresh milk or skim-milk available, pref- erably the latter. Pour off or remove the cream so that approxi- mately 750 grams of skim-milk are left in the jar. Weigh off exactly this amount in each jar. (3). Place the jars containing the milk in the sterilizer, and heat to 190° F. for one hour, if short of time. Preferably heat to 170° F. for one hour and a half. (4). Cool the skim-milk in the jars until it has a temperature of 68° F. (5). Remove the cap and inoculate with the exact amount of culture found necessary by previous experiment. (6). Replace the caps and seal the jars. Shake the jars thoroughly. This is very important. Jars cannot be shaken too much. (7). Place the jars in the incubator. (8). Turn on the fan and the thermostatic control; close doors tightly, and leave the jars undisturbed for 14 hours. Make sure that there is plenty of ice in the ice compartment. (9). At the end of incubating period examine the jars, and see that a heavy culture is produced. It should not show the presence of any whey on the top, or any signs of gas. (10). Place the jars in the ice chamber with plenty of cracked ice, or preferably keep it in ice water. Do not allow it to freeze. Culture is now ready to use. (11). Always keep in reserve one jar to make succeeding inoculations of the mother culture. Commercial Appucation 543 THE APPLICATION OF PURE CULTURES TO THE MANUFACTURE OF BUTTERMILK. In the manufacture of commercial buttermilk, there are various essentials that must be kept under careful control if the desired results are to be obtained. The success of the business will depend upon the ability to produce buttermilk with a good aroma, and a good flavor; one that is free from gas, and that will not separate, but that will remain smooth and creamy. Such a result can only be obtained by the application of scientitid methods of control, in its manufacture. The factors of the greatest importance are : (1). The use of a culture of the desired bacteria. This can be obtained and maintained only if propagated under conditions insuring uniform temperature control. (2.) A proper understanding of the process underlying the care, propagation and application of pure cultures as related to the production of buttermilk. (3). The use of skim-milk of the proper quality, the same to be successively pasteurized, cooled, inoculated, propagated, cooled again, and finally bottled at a low temperature. Butter fat may, or may not be added depending upon the trade requirements. QUANTITY OF CULTURE TO USE. The method of determining the quantity of culture to use as outlined earlier in this chapter, and which method is used so successfully by Frohring, is especially recommended. The suc- cess of the method hinges upon the use of a strain of culture of unusual vigor due to having been propagated under ideal con- ditions over a large number of unbroken generations. The potential ripening possibilities of such a culture is much greater than in the case of ordinary Cultures produced under usual factory conditions. A culture propagated under these ideal conditions possesses the ability to reach and pass through the logarithmic stage of growth in minimum time. Highly satisfactory results are obtained in practice by using two quarts of culture propagated as described above to every 100 gallons of skim-milk. The use of such a limited amount of culture effects several economies. Intermediate propagations between 544 Bacteriological Tests and Cultures the Culture Controller and the skim-milk to be inoculated can be entirely dispensed with. This makes it possible to propagate sufficient culture for relatively large amounts of buttermilk in the Culture Controllers only. No harm is likely to result if more than .50 per cent of culture is added, but the limit should be 2.00 per cent. When using ,50 per cent of culture great care must be taken to thoroughly distribute the culture in all parts of the skim-milk. WATER TO ADD TO THE SKIM-MILK. A good quality of skim-milk must be used. It is seldom possible to make a satisfactory product if the skim-milk is derived entirely from skim-milk powder. Fat may or may not be added in the form of milk, or cream, depending upon the kind of butter milk that it is desired to make. A high quality of commercial skim-butter milk is obtained when 10 per cent of water is added to the skim-milk before pasteurizing. The product thus obtained is of the viscosity usually demanded. Fig*. 128. Buttermilk Machine. Courtesy Creamery Package Manufacturing Co. HOW TO PASTEURIZE, INOCULATE AND INCUBATE THE SKIM-MILK. The skim-milk obtained as above is heated in a suitable butter milk vat ; either tinned copper or glass enameled, to 190° F., held at this temperature for one hour, and cooled promptly by means of both well water and ice water, or brine to about 70^ F. Equally Adding Culture to Skim-Milk 545 satisfactory results are obtained if the skim-milk is heated to 170° F. for one hour and a half and then promptly cooled sai described. Figf. 129. Buttermilk Machine. Courtesy J. G. Cherry Co. At this point the culture is added at the rate of two quarts to every 100 gallons. This refers to the culture propagated in the Mojonnier Culture Controller by the use of methods de- scribed in this chapter. The use of so little culture could not be advocated if the culture is obtained from different sources. The mixture is now thoroughly agitated for half an hour, and the cooling is continued to 68° F. The agitation is now stopped, and the milk in the vat held at 68° F. without agitating it, for about 14 hours. In practice the best plan is to so prepare the skim-milk that the pure culture can be added to it at about 5 p. m. At 7 a. m. the batch is then completely incubated, provided the proper method was used throughout. If the milk is propagated below GS^ F. a bitter flavor may develop, and if over 68° F. gassy fermentation may result. In summer the incubation should be started when the milk is a little under, and in winter a little over 68° F. This is of course, on account of the tendency of the milk to go to a temperature approaching room temperature. The critical point at the end of the ripening process is the point where whey begins to appear upon the top 546 Bacterioi^ogicai, Tksts and Cuwures of the milk. When the ripening is properly completed the curd will break clear and sharp when a spoon is inserted into the coagulated mass. The acidity at this point will be about .70 per cent. Pig-. 130. Pf audler Buttermilk Tank. Courtesy The Pfaudler Co. The agitation after ripening must not be too violent, nor carried on too long, as there is danger of a physical separation of the curd. The use of a centrifugal pump in handling the butter- milk should be avoided on account of its tendency to cause mechanical separation of the curd in the buttermilk. After the inoculation and agitation are complete, the butter- milk should be cooled immediately to at least 50° F., preferably under 50° F., but not under 40° F., and kept cold until delivered to the consumer whether in bottles or in bulk. If the buttermilk is cooled under 40° F., there is danger of freezing, causing ice crystals and subsequent dehydration of the casein which changes the physical properties of the product. All utensils must be kept clean and sterile and well tinned, otherwise bad flavors may be introduced into the product. 1 BuLGARicus Cultures 547 HOW BULGARICUS CULTURES ARE USED. Bulgariciis cultures are added for the purpose of giving to the buttermilk a characteristic sharp flavor, and particularly for advertising purposes in order to call the product Bulgarian buttermilk. Equally good results are obtained without using any Bugaricus culture, and its use is largely upon the decline. Fig*. 131. ButteTinilk Machine. Courtesy Davis-Watkins Dairymen's Mfg. Co. HOW TO PREVENT WHEYING-OFF, OR SEPARATION IN BUTTERMILK. It sometimes happens that the coagulated constituents in buttermilk Avill settle slightly upon standing, either in bottles or in cans, after the incubation and the cooling of the product have been completed. This will cause the appearance of a small layer of whey upon the top of the container. Sometimes this defect is objectionable, but as a rule by simple agitation the product can all be remixed. Inasmuch as this defect has no effect upon the flavor, remixing restores the buttermilk to its original condition. This defect sometimes occurs in the opposite 548 Bactkriological Tests and Cultures direction than as indicated above, — namely the water appears upon the bottom instead of upon the top of the container. Butter- milk containing no fat, or but little fat generally wheys off upon the top. That containing much fat wheys off upon the bottom. The difference is due to the relative density of the curd, in the two cases. Buttermilk in which the curd contains the proper amount of fat to balance the specific gravity of the milk serum obviously will not whey-off so readily. This relation at the present time is not well established. The exact cause of wheying-off is not clearl,y understood at this time. The two most important factors causing this defect are over-ripening and insufficient cooling after incubating. Other important factors are the use of too much starter, the use of skim-milk of inferior quality, the use of skim-milk containing too much fat, and too high holding temperatures. This emphasizes the importance of proper incubation as already described, and of prompt cooling at the close of the incubation period to at least 50^ F., and keeping the buttermilk at this low temperature until used. Likewise only skim-milk with a low fat content, of good flavor, and of good quality should be used. THE APPLICATION OF PURE CULTURES IN THE MANUFACTURE OF ICE CREAM. A new use for pure cultures that promises well, is in the manufacture of ice cream. Such a culture, imparts to ice cream a sharp, pleasing flavor; it gives increased viscosity to the mix, and it inhibits the growth of certain bacteria that cause bad flavors. This is a comparatively new application for pure cultures, and much remains to be learned upon this subject. THE APPLICATION OF PURE CULTURES IN THE MANUFACTURE OF COTTAGE CHEESE. The manufacture of cottage cheese is in many respects similar to the manufacture of buttermilk. The pure culture is added, in the same amounts as when manufacturing buttermilk ; the propagation is continued at 68 '^ F. for about 14 hours, or until the titratable acidity amounts to about .8 per cent. The coagu- lated milk is now gently heated to about 95° F., taking thirty to forty minutes, and the liberated whey is drained off. The Usii 01' CuivTUREis IN Cheese: 349 process of manufacture is then continued as usual, and is subject to several modifications that influence the composition, and also the physical properties of the product. The yield of cottage cheese ranges from 15 to 22 pounds per 100 pounds of skim-milk depending upon the composition of the skim-milk used, and the methods of manufacture employed. The total solids vary between quite wide limits, ranging from 20 per cent to 30 per cent. By using more scientific methods of control a product more uniform in composition can be manu- factured. The reader is especially referred to the works of Hall, Van Slyke and Hart-^ and Stocking'-^ for more detailed informa- tion upon this subject. THE APPLICATION OF PURE CULTURES IN THE MANUFACTURE OF BAKERS' CHEESE AND POT CHEESE. These are soft cheeses and the same are fully described b}^ Stocking.-^ In the case of bakers' cheese. Stocking recommends the use of from 1 to 3 pounds of culture for every 1000 pounds of milk. Likewise the addition of from % to 3^ ounce of rennet dissolved in water in the proportion of one part of rennet to forty parts of water. The incubating period is from twelve to fifteen hours, at a temperature of 75" F. The titratable acidity is then about .45 to .50 per cent. The curd is separated without heating. In the case of pot cheese, Stocking recommends the use of from .50 to 5.00 per cent of culture. The skim-milk from the separators is cooled to about 80° F. before adding the culture. The separation of the curd is hastened by heating slightly, before removing the whey. The curd from either bakers' cheese or pot cheese can be used to make cottage cheese. THE APPLICATION OF PURE CULTURES IN THE MANUFACTURE OF CHEDDAR CHEESE. The principle underlying the manufacture of all kinds of cheese is based upon condensing certain of the milk solids by separating the same from the water and certain other solids contained in the milk. If properly used pure cultures may be of very great value in the manufacturing of either American Cheddar Cheese or of 550 BacteriologicaIv Tests and Cultures many other types of cheese. The pure culture inhibits the growth of undesirable bacteria and hastens the proper ripening of the sweet milk. Only the best and purest culture should be used. The presence of undesirable bacteria may later cause serious defects in the cheese. According to Stocking, "ordinarily from 2^ to 5 per cent of culture will be sufficient to give the desired results." The growing power of the culture is no doubt a large factor in determining the quantity to use. The use of pure culture in cheese making helps to develop sufficient acidity to make it unnecessary for the curd to remain in the whey longer than is desired for the best results. The proper degree will usually be shown by an acid test of .19 to .21 per cent. At this point both color — if any is desired, 'and rennet or pepsin are added. The principles enumerated for making cultured buttermilk can be applied with marked advantage in the manufacture of cottage cheese. This applies particularly to the advantages derived from pasteiTrizing the milk before adding the culture, the quantity of culture to use, and the temperature to employ. THE APPLICATION OF PURE CULTURES IN THE MANUFACTURE OF RUTTER. One of the most important applications of pure cultures is in the butter industry. A good quality of culture inhibits the growth of bacteria that may cause the development of bad flavors in the butter, and it in itself helps to insure a good flavor in the finished product. These advantages are especially apparent in the case of butter that is held for some time before being consumed. Through the courtesy of the Telling-Belle Vernon Co.-^ we give outline of method used by them in applying cultures in making butter. In the case of cream that is to be churned the day that it is received, the cream is neutralized to about .16 to .18 per cent of acid. The neutralizer is added after the cream has been cooled from pasteurizing temperature to a temperature of about 90° F. Great care is taken to mix the neutralizer properly with the Use op Cultures in Butter 551 cream. The reader is especially referred to Hunziker-^ for detailed information regarding the best methods of neutralizing cream. After neutralizing about ten per cent of pure culture is added, and the cream is cooled immediately to 48 to 52° F. It is held at this temperature for 3 to 4 hours, at which time the acidity is about .23 to .24 per cent, and the cream is then churned. In the case of cream that is to be held over night, the pro- cedure is slightly different than that outlined above. After pasteurizing the cream is cooled from pasteurizing temperatures to about 90- F. The cream is now neutralized carefully to a final acid content of .10 per cent. The cream is then cooled to 52° F., and about 7 per cent of pure culture is added. The cream is held for about 12 hours, at the end of which time the acidity has reached about .30 per cent. The cream is now churned, and it yields a high quality of butter. The cream is held over night as described above, whenever this is possible. REFERENCES. 1 Melick, Chas. W. Dairy Laboratory Guide, p. 79, D. Van Nostrand Co. 1907. 2 Wilcox, E. V. Production and Inspection of Milli. 1912 Hawaii Agri. Sta. Bui. U. S. Dept. of Agri. 3, < Duckwall, E. W. Canning and Preserving, p. 365, plate 122. 6 Committee on Standard Methods for the Bacteriological Examination of Milk. Report, 3rd ed., American Public Health Association, 1921. " Committee on Standard Methods of Bacteriological Analysis of Milk. Report. Amer. Jour. Pub. Health, 6, 1315 — 1326, 1916. Committee on Bacterial Milk Analyses. Report of Progress. Amer. Jour. Pub. Hygiene, 4, 425 — 435, 1908. Slack, Francis H. Some observations on the bacterial examination of milk. Amer. Jour. Pub. Health, 7, 690 — 697, 1917. Berry, Jane L. Studies of laboratory media. Collected Studies, Bur. Laboratories, N. Y. City. S, 288 — 293, 1915. Sherman, J. M. The advantages of a carbohydrate medium in the routine bacteriological examination of milk. Jour. Bact., 1, 481 — 488, 1916. Conn, H. W. Standards for determining the purity of milk. The limit of error in bacteriological milk analyses. U. S. Pub. Health Service, Pub. Health Repts., 30, 2349 — 2395, 1915. Committee on Standard Methods for the Bacterial Examination of Milk. Report. Amer. Jour. Pub. Hygiene, 6, 315 — 345, 1910. Brew, J. D. and Dotterrer, W. D. The number of bacteria in milk. N. Y. Agr. Exp. Sta., Bull. 439, 1917. Breed, R. S. and Stocking, W. A. The accuracy of bacterial counts from milk samples. N. Y. Agr. Exp. Sta., Tech. Bull. 75, 1920. ' Breed, R. S. and Brew, J. D. Counting bacteria by means of the micro- scope. N. Y. Agr. Exp. Sta., Tech. Bull. 49, 1916. 552 Bacteriological Tlsts and Cultures REFERENCES. Werner, Percv. Plan for control of milk supplies in small cities. Jour. Dairy ScL. 1. 284"— 289, 1917. 8 Committee on Standard Methods for the Examination of Water and Sewage. Report, 4th ed., 115 pp., American Public Health Assn. 1920. » Sorensen, S. P. L. Ztschr. Biochem., 21. 131, 201, 1909; Ergebn. Physiol., 12, 393. 1912. Clai'k, W. M. and Lubs, H. A. The color i metric determination of hydrogen ion concentration and its applications in bacteriology. Jour. Bact., 2, 1 — 34, 109 — 136, 191 — 236, 1917. Clark, W. M. The determination of hydrogen ions. Baltimore, 1920. lo Barnett, G. D. and Chapman, H. S. Colorimetric determination of re- action of bacteriologic mediums and other fluids. Jour. Amer. Med. Ass., 70, 1062 — 1063, 1918. " Medalla, Tj. S. "Color standaj-ds" for the colorimetric measurement of H-ion concentration pH 1.2 to pH 9.8. Jour. Bact., 5, 441—468, 1920. '=Dearstyne, R. S. A study of the effect of cotton stoppers used in dilu- tion blanks on the numerical bacterial count, and of other practices in the technique of bacteriological laboratories. Jour. Dairy Sci., 1, 512 — 516, 1918. 13 Hill, H. W. The mathematics of the liacterial count. Amer. Jour. Pub. Hygiene, 4, 300—310, 1908. Breed, R. S. and Dotterrer, W. D. The number of colonies allowable on satisfactory agar plates. N. Y. Agr. Exp. Sta., Tech. Bull. 53, 1916. i'' American Public Health Ass'n., 370 7th Ave., New York. 1921. 's Commission on Milk Standards. Third report. U. S. Pub. Health Serv- ice. Pub. Health Repts., 32, 271 — 296, 1917. See also N. Y. City and N. Y. State Sanitary Codes. 16 Breed. R. S., and Brew, J. D. The control of bacteria in market milk by direct microscopic examination. N. Y. Agr. Exp. Sta., Bull. 443, 1917. 1" Model ordinance, Penn. State Dept. Health. Uocal ordinances. Butler and Reading, Penn. Frost. W. D. Comparison of a rapid method of counting bacteria in milk with the standard plate method. Jour. Inf. Dis., 19, 273 — 287, 1916. Frost, W. D. Counting the living bacteria in milk. A practical test. Jour. Bact., 2, 567 — 583, 1917. ^8 Tonney, F. O. Organization of control of pasteurization. Amer. Jour. Pub. Health, 10, 716 — ^723, 1920. Schroeder, M. C. Dirt sediment testing. A factor in obtaining clean milk. Amer. Jour. Pub. Health, 4, 50 — 64, 1914. Ruehle, G. L. A., and Kulp, W. L. Germ content of stable air and its effect upon the germ content of milk. N. Y. Agr. Exp. Sta., Bull. 409, 1915. Prucha. M. J., and Weeter, H. M. Germ content of milk. 1. As in- fluenced by the factors at the barn. 111. Agr. Exp. Sta. Bull. 199, 1917. Ayers, S. H., Cook, L. B., and Clemmer. P. W. The four essential factors in the production of milk of low bacterial content. U. S. Dept. Agr., Bull. 642, 1918. Ander.son, J. F. The frequency of tubercle i)acill! in the market milk of the City of W'ashington, D. C. U. S. Pub. Health and Marine Hosp. Ser., Hy- gienic Lab., Bull. 56, 167 — 197, 1909. i» Jackson, D. D.. and Melia, T. W. Differential methods for detecting the typhoid bacillus in infected water and milk. Jour. Infect. Diseases, 6. 194 — 204, 1909. -" Hastings, E. G., and Hoffman, C. Bacterial content of the milk of in- dividual animals. Wis. Agr. E'xp. Sta., Research Bull. 6, 1909. References 553 references. Sherman, J. M. Studies on the production of sanitary milk. Penn. State Co — — Assn. Report for 1914 — 15, p. 299 — 305, 1916. -^ Baker, J. C, and Breed, R. S. The reaction of milk in relation to the presence of blood cells and of specific bacterial infections of the udder. N. Y. Agr. Exp. Sta., Tech. Bull 80, 1920. --Buchanan (Journal of Infectious Diseases, 1918, 23, p. 109). "3 Barber (Journal of Infectious Diseases. 1908, 5, p. 379). '^* Penfold (Journal of Experimental Medicine in 1916, 24, p. 387). Buchner, Lougard & Riedlin (Centralblath f. Bakteriol, 1887, 11, p. 1). -6 W. O. Frohring, Creamery and Milk Plant Monthly, 1919, Vol. 8, No. 11, p. 61. -" Hall, F. H. Van Slyke. L. I^., and Hart, E. B. The Chemistry of Cot- tage Cheese. N. Y. Station Bulletin 245, 1904. -" Stocking, W. A.' Manual of Milk Products. The McMillan Co., New York, 1921. =" Submitted by VV. O. Frohring. -* Hunziker, O. F. The Butter Industry. La Grange, Illinois. CHAPTER XVII ANALYSIS AND MISCELLANEOUS TESTS OF DAIRY PRODUCTS Methods for determining the percentages of fat and solids in dairy products are given in Chapters III, VII, VIII. This chapter contains methods for determining the percentages of other constituents of milk and its products and various tests of value in the dairy industr3^ Pigr. 132. Specify Gravity ChainomatJc Balance. Courtes^■ Christian Becker Co SPECIFIC GRAVITY DETERMINATIONS. Equal volumes of the same, or of different milk products, usually do not have equal weights. This is due both to difference in the quantity of solid matter present and to dift'erences in the density of the various components of the solid matter. [554] Specific Gravity 555 In the metric system the unit of volume is the cubic centi- meter, and the unit of weight is the gram. A mass of one gram of water at its temperature of greatest density (4°C.) has a volume of 1 cubic centimeter, and the specific gravity of a substance is the weight of one cubic centimeter ex- pressed in grams. Therefore, it follows that the specific gravity of water at 4°C. equals 1. The specific gravity of any other liquid, or of a solid, may be obtained by dividing the weight of any volume of it by the weight of an equal volume of water. When the temperature of water changes in either direction from 4°C. the volume expands and its specific gravity decreases. In practice, however, it is customary to make specific gravity determinations at 15.55° C. (60° F.) and to assume that water at that temperature has a specific gravity of 1. The specific gravity of liquids is most accurately determined by using a specific gravity bottle, and a delicate chemical balance. The best form of specific gravity bottle is fitted with a ther- mometer that also serves as a ground glass stopper, the bulb of the thermometer extending down into the center of the bod}^ of the bottle. A side arm with capillary tube opening and extend- ing upward a short distance from the shoulder permits the bottle to be filled completely. Before making a determination the bottle must be thoroughly cleaned, dried, and cooled to the temperature to be used in the determination, until its weight is constant. It is then weighed ac- curately on the chemical balance and the weight is recorded. The bottle is then filled with water and brought to the temperature it had when it was first weighed. The bottle is wiped dry, Pigr. 133. Specific Weighed and the weight recorded. The exact Courtesy Arthur temperature of the water in the bottle when the H. Thomas Co. weighing is made should be noted. The bottle is then emptied, rinsed free of water with some of the liquid the specific gravity of which is to be determined, and finally filled with the liquid, wiped dry and weighed. The weight of the liquid divided by the weight of the water gives the specific gravity of the liquid. If milk is the liquid under observa- 556 Analysis of Dairy Products tion, great care must be taken to have it thoroughly mixed before rinsing and filling the bottle. A Sprengel Tube may be used in place of a specific gravity bottle. It is a U shaped glass tube, holding about 15 cc, the free ends being drawn to narrow capillaries and bent outward at right angles. Ground glass caps are fitted to the free ends and a line to be used in exact adjustment of the liquid, is etched on one of the capillary tubes. ^.^ ^^^ sprengei Tube. In determining the specific gravity of ^,.^,,^1- h. Thomas co. milk the weight of the empty dry tube is accurately determined. The tube is then filled with water and weighed again after bringing its contents to the desired tempera- ture by immersing the tube in water the temperature of which is controlled at 15.5° or 20° C. as desired. The operation is then repeated placing the milk in the tube in place of water. Divide the weight of the milk by the weight of the water to obtain the specific gravity. The Westphal balance is an instrument devised especially for the purpose of making specific gravity determinations of liquids. It consists of a perpendicular rod supporting a beam that has a glass plummet suspended at one end and a pointer attached to the other. When the plummet is suspended in the air the pointer indicates zero. When the plummet is immersed in a liquid its weight is decreased in amount equal to that of the liquid dis- placed. The arm carrying the plummet is provided with notches and respective riders which indicate definite weights. The riders are added until the loss of weight due to the displaced liquid is overcome and the pointer again rests at zero. The sum of the weights represented by the riders used equals the weight of the liquid displaced. The weight of the liquid displaced, divided by the weight of water displaced when determined in a like manner, gives the specific gravity of the liquid. A single weight is pro- vided with the instrument which brings the pointer to zero when the plummet is suspended in water. The temperature of the SpKcific Gravity of Milk 557 liquid aud the water should be the same (15.55° C.) when the determination is made. Determining the specific gravity of milk by means of lactometers: — Hy- drometers are instruments used for the purpose of determining the specific gravity of liquids. They consist of hol- low cylindrical shaped bodies of glass weighted at one end with shot or mercury and drawn out to a long nar- roAv stem at the other end. The weight is added to make the instrument take a perpendicular position when it is floated in a liquid. The stem contains a scale that indicates the specific grav- ity of the liquid. In the better form Tig. 135. westphai Balance. ^^ instrument the bulb of a thermome- Courtesy Arthur H. Thomas Co. ter is sealed in the lower end, the stem of the thermometer extending up through the hollow body and the thermometer scale appearing in the stem of the hydrometer above, or on the side opposite the hydrometer scale. Lactometers are forms of hydrometers made for the purpose of determining the specific gravity of milk. While the results ob- tained by their use are not quite as accurate as those obtained by means of a delicate balance, they enable an operator to make a large number of specific gravity determinations in a comparatively short time with sufficient accuracy to serve the purpose of routine inspection work. Several different lactometers have been devised in this country and Europe. They all depend upon the same principle, namely, that bodies floating in a liquid displace a mass of the liquid equal to their weight. The only real difl^erence between the varieties of lactometers is in the graduations on the lactometer scale. Only two kinds af lactometers have come into general use in the United States. They are the Quevenne lactometer and the N. Y. State Board of Health lactometer (B. of H. lactometer) The 558 Analysis of Dairy Products Quevenne instrument derives its name from the man who invented it. The scale in its stem is graduated from 15 at the top to 40 at the bottom, each graduation representing a difference of 1.0 on the lactometer scale. When the instrument is floated in milk of average composition the reading on the scale at the surface of riff. 136. Quevenne Iiactometer. Pig-. 137. Baume Hydrometer. Tig. 138. N. Y. Board of Health or Spence Iiactometer. the liquid should be about 32. By prefixing "1.0" to the lacto- meter reading, the specific gravity is obtained. Thus the specific gravity of average milk is 1.032. A vessel that holds exactly Lactometers 559 1000 pounds of water when full Avoiild hold 1032 pounds of milk of average composition. It is considered that the Quevenne lacto- meter reading of pure milk should not fall below 29.0. Lactometers are made to show correct readings at 60^ F. In practice, however, it is permissible to make the lactometer reading when the temperature is within 10° of 60 either above or below. As changes in temperature affect the density of liquids, it is then necessary to make a temperature correction. The correction on the Quevenne scale is made by adding 0.1 to the lactometer reading for each temperature degree above 60° F. and to subtract 0.1 from the lactometer reading for each degree below 60° F, Assuming that the Quevenne lactometer reading of a sample of milk was 31 at 67° F., the correction to be added would be 0.7. Then 31.0+0.7=31.7. And the specific gravity of the milk would be 1.0317. Shaw and Eckels^ devised a modification of the Quevenne lactometer the graduations of which indicate variations in specific gravity as small as 1 in the fourth decimal place. Such an instru- ment must have a very slender stem and large body, which makes it very fragile, and while it can be used sometimes to advantage in the laborator}^, the stronger though less accurate instrument is favored for general inspection work. The B. of H. lactometer, somtimes known as Spence's lacto- meter (from the name of the man who devised it) has a scale that is graduated from to 120. There are 60 divisions in the scale, each division equaling 2 B. of H. lactometer degrees. When the instrument is floated in water the point on the scale is located at the surface of the liquid, and when it is floated in milk of average composition the reading at the surface of the milk is about 110. The instrument shows correct readings in milk at 60"^ F., but when the temperature of the milk is within 10 de- grees of 60 a correction factor may be used. The correction is made by adding 1.0 to the lactometer reading for each 3° F. above 60. and subtracting 1.0 for each 3° F. below 60. Thus if a sample of milk gave a B. of H. lactometer reading of 112 at 51° F. it Avould read 109 at 60° F. iV^) 112— I ^ I =109 560 Analysis of Dairy Products The relation between the lactometer scales. A reading of 29 on the Quevenne scale corresponds to a reading of 100 on the B. of H. scale. Therefore 1 on the B. .of H. scale equals 0.29 on the n\ Em -.hO: -. JE).\A il5 r^ -23. 34.8 4a ^~\ Lo^ I.OZ g IDI5 IP20 lei^ r>k ^-^ .7^ 1.4, -U. r23 .2^ 3.5 4.1 4.3 v5.6 -3- -4- 5- -6 N.Y. BOARD OF HEALTH LACTOMETER QUEVENNE LACTOMLTtR 5CALL SPECIFIC GRAVITY SCALE TWADDELL 5CALL BAUME 5CALE Tig. 139. Relation between B. of H. Iiactonieter, Quevenne Iiactometer and Specific Gravity Scales. Quevenne scale. (29-^100=0.29.) To convert the B. of H. read- ing to the Quevenne reading, multiply the B. of H. reading by 0.29. Then, by prefixing "1.0" to the product the specific gravity is obtained. Lactometer Readings 561 As a result of the extended study of the density of pure milk it has been learned that the lactometer readings with rare excep- tions fall between 29 and 33.5 for the Quevenne lactometer and between 100 and 116 for the B. of H. lactometer. But a correct lactometer reading alone is not a guarantee of purity, as removing a part of the fat increases the reading and the addition of water decreases it. By operating skillfully the lactometer reading may be held constant as long as any fat is present. For this reason experienced inspectors depend to a considerable extent upon the appearance of the milk, especially the richness of the coating and the rate of its flow off of the lactometer when the instrument is removed from the mass of milk. If the coating appears thin a sample may then be taken for chemical analysis. The relative effect of fat and solids not fat on the lactometer reading". The fat is the lightest solid that milk contains. Any increases in its percentage, without an increase in the other solids, tends to lower the lactometer reading. It happens that, in the elaboration of milk in the udder of the animal, when an in- crease in the fat occurs, there is also a sufficient increase in the solids not fat to a little more than offset the lowering of the density occasioned by the increase in fat. Therefore, it is normally found that naturally rich milk gives a higher lactometer reading than poor milk. If the percentage of fat rises much above 6%, however, the increase in solids not fat is usually not enough to counterbalance the fat and the lactometer reading is then lowered a little. The relative effect of the percentages of fat and solids not fat on the density of the milk may be explained by an example. Suppose that a sample of milk containing 4 per cent of fat and 9 per cent of solids not fat gives a Quevenne lactometer reading of 33, and that after all of the fat is removed by skimming the lactometer reading is 37. The increase in density due to the removal of the fat is 4 on the lactometer scale. As there was 4 per cent of fat in the milk each per cent of fat caused a decrease of 1 on the lactometer reading. The whole milk contained 96 parts of skim-milk (milk serum) and 4 parts of fat, but when the fat was removed the remainder was 100 parts skim-milk. As the whole milk contained 9 parts of solids not fat the solids not fat in' the skim-milk may be calculated by the following proportions : 562 Analysis of Dairy Products 96 : 100 : : 9 : X X=9.37, or the percentage of solids not fat in the skim-milk. If there were no solids not fat in the skim-milk the remainder would be water and the lactometer reading would be 0. There- fore 37, or the lactometer reading of the skim-milk, divided by 9.37 gives the effect of 1 per cent of solids not fat in increasing the lactometer reading. 37.00 ^9.37=3.94, or the increased reading due to 1 per cent of solids not fat. As it was shown above that 1 per "cent of fat decreased the lactometer reading 1, it appears that 1 per cent of solids not fat has 3.94 times the effect in raising the reading that 1 per cent of fat has in lowering it. The use of formulas in calculating the composition of milk. When the percentage of fat in a sample of milk and the lactometer reading are known the approximate composition may be derived by the application of a formula. As a result of much study different formulas have been developed by Fleischmann, Rich- mond, Babcock and others. Babcock's formula is more generally used in the United States. Babcock's formula: (1.) L -r +.2F=solids not fat. 4 ' Another formula which gives good results especially with naturally rich milk is the following : (2.) L+F — - — ^solids not fat. 4 L=Quevenne lactometer reading at 60^ F. F:=Per cent of fat. The following example shows the application of forrniila (1). A sample of milk contained 3.60 per cent of fat and gave a lacto- meter reading of 31.6. What was the percentage (a) of solids not fat, (b) of total solids, (c) of water. 31.6-^4=7.9 3.6X.2=0.72 7.9+0.72=8.62, or per cent of solids not fat Use; of Lactometers 563 8.62+3.60=12.22, or per cent of total solids. 100.00—12.22=87.78, or per cent of water. Another formula- for calculating the solids not fat in milk when the N. Y. State Board of Health lactometer is used, is the following : [{r.O-'] + - =S. N. F. in which L=N. Y. Board of Health lactometer reading, F=per cent of fat. This formula gives fairly good results with milk of average composition and with rich milk but the results are liable to be a little too high when it is used on milk of low solids content. Lactometers used to determine the specific gravity of concen- trated milk product. The determination of specific gravity is frequently of very great importance in arriving at the approxi- mate total solids content of various concentrated milk products. The lactometers most commonly used for this purpose are the Baume and the Twaddell. In order to permit of closer readings, the practice is to make lactometers of various ranges, to suit the products upon which they are to be used. In the case of the Baume lactometer, the ranges given in Table 95 are those most commonly used. TABLE 95. Range of Baume Lactometers with Products Upon Which They Are to Be Used. Baume readings upon scale 60° F. 1/10 degree divisions. Corresponding specific gravity scale. Name of products upon which lactom- eters are to be used. to 15 1 to 1.1154 Evaporated milk, plain condensed milk, ice cream mix, condensed but- termilk. 15 to 27 1.1154 to 1.2288 Extra heavy plain condensed milk and light sweetened condensed milk. 27 to 36 1.2288 to 1.3302 Sweetened condensed whole and skim- milk. 564 Analysis of Dairy Products The corresponding readings, with converting formulas upon true specific gravity, Baume and Twaddell scales are given in several tables in appendix, covering a wide range. This affords a ready means of converting one scale into another. A compari- son of the scale readings of the different instruments used in determining the specific gravity of milk and its products is shown in Fig. 139. CALCULATING THE PERCENTAGE OF ADULTERATION WHEN MILK HAS BEEN SKIMMED OR WATERED. The forms of milk adulteration that are practiced most fre- quently are watering and skimming. They may be very difficult to detect where the adulteration is small, and especially difficult when there is no means of learning the composition of the original pure milk. This must be known where accurate calcu- lations are to be made, and it is necessary to also know the per- centages of fat and solids not fat in the adulterated sample. The latter may be determined by any of the means of analysis at hand. In routine work where the aim is to obtain the approximate com- position of a large number of samples the solids not fat may be determined by means of the formulas given on page 562. In the absence of means for determining the composition of the original pure milk, it becomes necessary to take as a basis for the calculation, the prevailing standard fixed by Legislative or Health Board enactments for the location where the adulterated milk was exposed for sale. Calculating- the percentage of fat removed by skimming". Subtract the percentage of fat found in the suspected sample from the percentage of fat in the pure milk, or in the absence of this information, subtract it from the percentage fixed as a standard. Then divide the difference by the percentage of fat in the pure milk, or by the standard as the case may be. Multiply the quotient by 100 and the product equals the percentage of fat that was removed by skimming the pure milk. Problem : Suppose that a sample of partially skimmed milk contained 2.8 per cent of fat, and that before it was skimmed it contained 3.8 per cent of fat. What percentage of the fat was removed by skimming? Calculating Adultkrations 565 Solution : 3.80—2.80=1.00 1.00-^.038=25.78. per cent of fat removed by skimming. Calculating the per cent of water added to milk. This calcu- lation should be made on the solids not fat. Problem : Suppose that a sample of milk contained 8.8 per cent of solids not fat before it was watered, and 7.00 per cent of solids not fat after it was watered. What percentage of water was added 1 Solution : 8.80—7.00=1.80 1.80-^8.80=.2045 .2045X100=20.45. or per cent of water added. Calculations when the milk is both skimmed and watered. The specific gravity of milk is increased by skimming and de- creased by watering. Therefore by skimming off some of the fat and skillfully adding water the specific gravity or lactometer reading may be kept the same after the adulteration that it was before. When naturally rich milk is adulterated lightly in this way, the adulteration is very difficult to detect unless it is pos- sible to learn the composition of the original pure milk. Problem : A sample of pure milk contained 4.6 per cent of fat and 8.86 per cent of solids not fat. After adulteration by skimming and watering the milk contained 3.00 per cent of fat and 8.10 per cent of solids not fat. What percentage of the fat was removed by skimming and what percentage of water was added? Solution: (1). Calculate the percentage of water that was added as indicated by the relative amounts of solids not fat in the two samples : : 8.86— 8.10=.76 .76-~8.86=.0857 .0857X100=8.57, or per cent of water added. (2). Calculate the total loss of fat: 4.6—3.00=1.6 1.6^4.60=.3478 .3478X100=34.78, or total per cent of fat lost. (3). Calculating the fat removed by skimming: When water is added to milk it reduces the percentages of all the 566 Analysis of Dairy Products solids present in the same proportion. Therefore the loss of fat by watering must have been 8.57 per cent, or the same per- centage as the solids not fat, then : 34.78 — 8.57=26.21, or percentage of the fat removed by skim- ming. This answer is not absolutely correct as the percentage of solids not fat in the partly skimmed milk is slightly increased by the removal of some of the fat from the pure milk. THE DETERMINATION OF VISCOSITY IN LIQUID DAIRY PRODUCTS. The viscosity of liquid dairy products is most easily and most accurately determined by means of the Mojonnier-Doolittle Vis- cosimeter, illustrated under Fig. 140. This instrument embodies all the principles of the original Doolittle viscosimeter. The viscosity readings obtained by this method are relative only. Under equal conditions they are strictly comparable. The standard viscosimeter is fitted with viscosity balls giving three ranges of viscosity as follows : (1). Large viscosity ball. Applicable to fresh whole milk or skim-milk or other fluids of similar viscosity. (2). Medium viscosity ball. Applicable to evaporated milk, cream, plain condensed milk, or products of similar viscosity. (3). Small viscosity ball. Applicable to sweetened condensed milk, superheated milk, or products of heavy viscosity. The wires, balls and dials of equal range can all be accurately calibrated, and the results obtained within a given range are closely comparable. The results are expressed in terms of "de- grees of retardation." The dial is graduated in single degree divisions up to 360 degrees. Temperature exerts a large influence upon viscosity. In expressing viscosity the reading should always be reduced to a standard temperature. In the case of evaporated milk the cor- rections to make for temperature are expressed in Table 141. The most satisfactory results are obtained where the viscosity determination can be made under standard temperature conditions. ViSCOSI METER 567 DIRECTIONS FOR OPERATING MOJONNIER-DOOLITTLE VISCOSIMETER. (1). Fasten one end of the wire in the knurled nut upon the top of the bent support, and the other end in the dial knob. Adjust the vertical position of the dial by raising or lowering rig-. 140. Mojonnier-Doolittle Viscosimeter. the wire holder until the small lug upon the bottom of the dial is in the proper position to engage the trip upon the under right hand side of the stand. 568 Analysis of Dairy Products (2). Adjust the horizontal position of the dial until 0^ is in a line with the pointer upon the front of the frame when the dial is in balance in the air. Center the dial in the open space by means of the adjusting screws. (3). Place the sample in a cup, or make the test directly in the can. Temperature exerts a large influence upon viscosity. Viscosity increases as the temperature decreases, or vice versa. Therefore, test at constant temperature, or correct for the differ- ence in the temperature, using the proper corrections to apply upon the product under test. Obviously the correction will vary with the product. Properly center the cup or can. (4). Lower the ball into to^lt.turnin \ ' THIS DIRECTION the sample. Turn the dial clockwise through one revolu- tion, stopping at the 0° in the line with the pointer. Hold dial in place by means of the lug and trip. When ready, sharply release the trip. Note the degree where the dial stops just before it starts upon return ^ "^'^^iki^^ canbeta>4 inches deep, 2i/^ inches in diameter, and holding about 250 cc. It is equipped at its top edge with a heavy rubber ring on which the moisture evaporating dish is inverted, and with a lightning jar wire clamp for pressing the evaporated dish down on the rubber ring. One 100 cc. glass cylinder (low style). One 25 cc. pipette. One or more 150 cc. flasks (cone shape) for titrating. One 50 cc. burette with stand. One large bottle, with glass tubing and clamps to connect with burette, for standard silver nitrate solution. Salt Tests 617 One small bottle for potassmm chromate solution. Chemicals. — Silver nitrate solution containing 7.265 grams silver nitrate in 1000 cc. water. Potassium chromate solution. <^^> Tig. 149. Hunziber Salt Test Apparatus. Operation of test. — This test is intended to be a continuation of the moisture test in which an evaporating dish of a diameter of 25^ inches is used. (1). At the conclusion of the moisture test fill the 100 cc. cylinder to the mark with warm water, temperature about 100° F., and pour this water into the salt tester. (2), Invert moisture evaporating dish over rubber ring of salt tester and make the dish fast by means of wire clamp. (3). Now shake the salt tester vigorously, giving it about 30 shakes. This causes the salt in the evaporating dish to be washed out by the warm water. (4). Remove evaporating dish and transfer with pipette 25 cc. of the salt solution from the salt tester into the titrating flask. (5). Add 1 cc. of potassium chromate solution to the titrating flask and from burette slowly add silver nitrate solution until a 618 Analysis of Dairy Products permanent brick-red precipitate is obtained. The titrating flask must be constantly and thoroughly agitated by a rotating motion while the silver nitrate solution is added. (6). If a 10-gram sample of butter is used in the moisture test, each cc. silver nitrate solution represents .1 per cent salt. Assuming that 35 cc, silver nitrate solution was used, the butter then contained 35/10=3.5% salt. (7). If the sample of butter is not exactly 10 grams, but somewhat more or less, the per cent of salt is readily calculated by dividing the cc. silver nitrate solution required, by the exact weight of the sample of butter. Sa.y the sample weighed 10.5 grams and required 35 cc. of silver nitrate solution, the butter then contained 35/10.5=3.3% salt. (8). This salt test occupies about five minutes. It is exceed- ingly simple and accurate, when made in accordance with the above directions. It eliminates the weighing of the sample for the salt determination and it automatically washes the moisture evaporating cup. For uniformly reliable results the following precautions must be observed : (a). Do not slobber the melted butterfat in the evaporating dish, over the outside of the salt tester. The butter must stay inside of the periphery of the evaporating dish, when the latter is inverted over the tester. (b). Do not use water at a temperature lower, nor much higher, than 100° F. Water must be warm enough to melt the fat. If too warm it will generate pressure when shaking the tester, causing loss of contents. (c). Strap the evaporating dish down to the tester, so that there is no leak around the rubber ring. (d). Shake vigorously thirty (30) times. (e). Give the titrating flask the proper rotating movement for vigorous and continuous agitation, while the silver nitrate solution runs from the burette. (f). Stop titration when the desired color has been reached (brick-red). (g). It is necessary to give the fat time to rise in the tester after shaking. This requires about one minute. For this reason. Butter Tests 619 the tester should be set down after shaking, and the aluminum cup taken off and wiped dry and gotten ready for the next weighing of butter. While this is done, the fat in the tester automatically rises to the surface, (h). If the edges of the evaporating dish become uneven, due to wear, causing the cup to leak when inverted over the rubber ring of the tester, invert the cup over a piece of fine emery cloth, and wear down the edges until even. 10. The speed of the entire test will much depend on the prop- er planning and organizing of the work of both the moisture and the salt test, so as to avoid any waiting between steps, such as waiting for the evaporating dish to cool, or for the fat to rise to the surface in the tester. It has been found that the maximum speed is obtained by running the moisture and the salt tests of three samples together. 11, Use only evaporating dishes without lips. Determination of the free fatty acids in butter A. 0, A. C. Method : Weigh 20 grams of the clear filtered fat into a flask, add 50 c, c. of 95%' alcohol which has been neutralized with weak caustic soda, using phenolphthalein as indicator, and heat to the boiling point. Agitate the flask thoroughly in order to dissolve the free fatty acids as completely as possible. Titrate with tenth-normal alkali, agitating thoroughly until the pink color persists after shaking. Express the result as cubic centimeters of tenth-normal alkali required to neutralize the free acids in 100 grams of the fat, Halpen's test for cotton seed oil: A. 0, A. C. Method. Dis- solve one gram of sulphur in 100 grams of carbon disulphide and mix with an equal volume of amyl alcohol. Place about 8 cc, of the clear melted fat, or oil, in a test tube and add an equal volume of the above reagent. Mix and heat the test tube in a bath of boiling saturated salt solution for one hour. As little as one per cent of cotton seed oil produces an orange-red color. Distinguishing butter, renovated butter and oleomargarine.-- Examination of the melted substance: Fill a glass test tube or similar transparent container with the fat and heat at a 620 Analysis of Dairy Products temperature of 50° C. until the fat is completely melted and the' water and curd has settled. The melted fat from butter will be clear and bright in appearance while that from renovated butter and oleomargarine will be cloudy and turbid. Vega's test. — Filter some of the fat through a hot dry filter into a test tube, placing the tube in boiling water for 2 minutes. In another large test tube place 20 cc. of a mixture of 1 part glacial acetic acid, 6 parts ether and 6 parts alcohol. Add about 1 cc. of the hot filtered fat to the reagents in the large test tube. Stopper the tube and shake well. Immerse in water at 15° C. (60° F.) and let stand 15 minutes. Pure butter will leave the contents of the tube almost clear while oleo- margarine will give a marked deposit. Foam test.-" — Melt in a spoon a piece of the sample about the size of a hickory nut over a lamp or gas flame, heating slowly until the fat is nearly melted, then more rapidly to boiling. With butter, foam forms and remains for some time, usually filling the spoon heaping full. On the contrary, the bubbles from oleo- margarine and renovated butter break almost immediately on forming, so that very little foam remains to obscure the surface of the melted fat. The Waterhouse test.^* — The Waterhouse test distinguishes between butter fat and foreign fat but does not distinguish between butter and renovated butter. Operation: Half fill a pint tin cup or beaker with skim-milk and heat nearly to boiling, add about 10 grams of the fat and stir with a small wooden splinter about the diameter of a match until the fat is melted. Set the cup in a pan of ice water and stir briskly with the splinter. Continue the stirring until the milk is cold enough to congeal the fat. The latter may then be collected into a mass by means of the splinter if the fat is from oleomargarine. Butter fat on the other hand, from either gen- uine or process butter, will not gather in a lump but will float quite uniformly in small particles on the surface of the liquid. CHEESE ANALYSIS. A. O. A. C. METHOD, (a). Preparation of Saniple.~When the cheese can be cut, a narrow, wedge-shaped segment reaching from the outer edge to the center of the cheese is obtained. This is to be cut into strips Cheese Analysis 621 and passed through a sausage-grinding machine three times. When the cheese cannot be cut, samples are obtained with a cheese trier. If only one plug can be obtained, this should be taken perpendicular to the surface at a point one-third of the distance from the edge to the center of the cheese. The plug should reach either entirely through or only half-way through the cheese. When possible, draw three plugs — one from the center, one from a point near the outer edge, and one from a point half-way between the other two. For inspection purposes, the rind may be rejected ; but for investigations requiring the absolute amount of fat in the cheese the rind is included in the sample. It is preferable to grind the plugs in a sausage machine, but when this is not done they are cut very fine and carefully mixed. (b). Determination of Water. — From 2 to 5 grams of cheese should be placed in a weighed platinum or porcelain dish which contains a small quantity of porous material, such as ignited asbestos or sand to absorb the fat which may run out of the cheese. This is heated in a water oven for ten hours and weighed ; the loss in weight is considered as water. Or, if preferred, the dish may be placed in a desiccator over concentrated sulphuric acid and dried to constant weight. In some cases, this may re- quire as much as two months. The acid should be renewed when the cheese has become nearly dry. See Chapter VIII for method for determining water in cheese, using the Mojonnier Tester. (c). Determination of Fat. — Cover the perforations in the bottom of an extraction-tube with dry asbestos felt, and on this place a mixture containing equal parts of anhydrous copper sulphate and pure, dry sand to the depth of about 5 cm., packing loosely. Cover the upper surface of this material with a film of asbestos. On this are placed from two to 5 grams of the sample of the cheese. The tube is placed in a continuous extraction apparatus, and treated for five hours with anhydrous ether. The cheese is removed and ground to a fine powder with pure sand in a mortar. The mixed cheese and sand are replaced in the extraction-tube, the mortar washed free of all matter with ether, the washings being added to the tube, and the extraction is con- tinued ten hours. See Chapter VII for method for determining the fat in cheese, using the Mojonnier Tester. , 622 Anai^ysis of Dairy Products (d). Determination of Nitrogen. — Make a determination of nitrogen by the Kjeldahl method, using about 2 grams of cheese, and multiply the percentage of nitrogen by 6.25. (e); Determination of Ash. — The dry residue from the water determination may be used for the ash. If the cheese be rich in fat, the asbestos will be saturated therewith. This may be ignited carefully, and the fat allowed to burn off, the asbestos acting as a wick. No extra heat should be applied during this operation, as there is danger of spurting. When the flame has died out, the burning may be completed in a muffle at low redness. When desired, the salt may be determined in the ash in the manner specified under butter analysis, page 614. (f.) Determination of Other Constituents. — The sum of the percentages of the different constituents, determined as above, subtracted from 100 will give the amount of organic acids, milk sugar, etc. in the cheese. (g). Provisional Method for the Determination of Acidity in Cheese. — To 10 grams of finely divided cheese, add water, at a temperature of 40° C, until the volume equals 105 cc. ; agitate vigorously and filter. Titrate portions of 25 cc. of filtrate, cor- responding to 2.5 gram of cheese, with standardized solution of sodium hydroxide, preferably one-tenth normal. Use phenol- phthalein as indicator. Express amount of acid as lactic. Troy's Cheese Moisture Test. This test provides a fairly rapid and accurate method for determining the percentage of moisture in cheese. It is practical for factory use and also serves well for the purpose of determining the percentage of moisture in butter. The high percentage of fat in butter permits rapid heating at a comparatively high temperature in an open dish without danger of loss by spattering or charring of the proteins until all of the moisture is driven off. But when cheese is treated similarly some of the solids will spatter out of the dish. There is not enough fat present to prevent the casein from stick- ing to the bottom and sides of the dish, charring and volatilizing some of the cheese solids. This test overcomes these difficulties by providing a double walled copper cup, space between the walls Cheesr Analysis 62.^ for holding oil into which a thermometer may be inserted, thus providing a means of determining the temperature and permitting its control. A scale for weighing the cheese, and a flask for holding it ^hile drying and a small alcohol lamp or gas flame for heating the cup are necessary. The Troy Moisture Tester is illus- trated under Fig. 150. Operation: In operating the test the alcohol lamp is first lighted, so that the oil bath may be warming while the test sample is under preparation. A representa- tive sample of the cheese, which may be taken with a cheese trier and held in a glass stoppered sample jar, is then cut into parti- cles about the size of kernels of wheat with- out removing it from the jar. This may be done with an ordinary table knife that has had the end squared and sharpened. The clean dry flask is then accurately balanced on the scales and a 5-gram weight is placed in the opposite scale pan. Particles of cheese from the prepared sample are put into the flask until the scales comes to an exact balance. Great care should be taken to avoid loss of moisture from the cheese during the preparation of the sample. rig-. 150. Troy Moisture Tester for Cheese. With the thermometer in the oil bath I'egistering a temperature between 140° and 145° C. (or between 284° and 293° F.), the flask is placed in the cup of the oil bath and the flat, disk-shaped cover is adjusted over the apparatus. The flask should remain in the bath for fifty minutes, the temperature being kept between 140° and 145° all of the time. The flask is then removed, covered, and allowed to cool to room temperature in a dry place. It is then weighed, and the quotient obtained by dividing the loss in weight by the original weight, multiplied by 100, gives the percentage of water in the cheese. The following shows the method of computation : Problem : Five grams of cheese were heated until the moisture was evaporated. The remaining substance weighed 3.15 grams. What percentage of water did the cheese contain ? 624 Analysis of Dairy "t^roducts Answer: 5.00—3.15=1.85 1.85-^5 =0.37 0.37X100= 37, per cent of water in the cheese. A butter moisture scales with an extra 5 grams weight may be used for weighing out the 5 grams of cheese. If the scales indicate the amount of moisture in 10 grams of butter by per- centage graduations on its beam, or by percentage weights, then it is necessary to multiply by 2 the percentage indicated by such scales or percentage weights when only 5 grams of cheese are used. Troy's Cheese Salt Test. Place a representative sample of the cheese in a half pint sampling jar or similar container. Using an ordinary table knife, or one that has had the end of the blade squared and sharpened, cut the cheese sample into particles as small as kernels of wheat. Mix thoroughly and weigh 10 grams into a crucible, or into a silica or platinum dish. Dry at a temperature of 100° C, or a few degrees higher and then ignite to a gray ash, preferably in a muffle. Wash the ash from the dish into a flask and make up with water to 300 cc. Stir thoroughly to bring all of the salt into solution and to make the solution homogeneous. Neutralize with dilute nitric acid. Draw a Babcock pipette full to the mark of the solution and run it into an evaporating dish or white cup, add two or three drops of a 10% solution of potassium chromate, and slowly run in tenth- normal silver nitrate solution from a 10 cc. burette graduated to 0.1 cc. until a permanent light brown color is obtained. Each cc. of tenth-normal silver nitrate solution required equals one per cent of salt in the cheese. THE MELTING POINT OF MILK FAT. As milk fat is composed of a number of different fats having different melting points and the percentages of these fats vary in different samples, the melting point of the substance is not sharply defined. Determinations of the melting point of samples from many sources by different investigators place the range of Melting Point of Fat 625 temperature within which the melting point should fall betw^een 30 and 36.6° C. (87 and 98° F.). The solidifying points range between 19 and 25° C. (66 and 77° F.). Where the quantity of the fat permits, the simplest method for determining the melting point is to immerse an accurate ther- mometer in the partly molten and partly solid mass. In many instances, however, only a limited amount of the fat is available. Under these circumstances a drop of the melted fat is drawn into a thin walled glass tube about 1 mm. in diameter and cooled until completely solidified. The tube is then attached to the side of a ther- mometer, the part containing the fat being held on a level with the bulb. The thermometer and tube are then heated slowly in water or sulphuric acid until the fat begins to appear translucent, when the temperature is taken. The temperature should be taken again when the fat becomes nearly trans- parent. In order to avoid error due to the uneven heating of the immersion fluid, Dennis-' advises the use of sulphuric acid in a tube like that shown in Fig. 151. When operating the test the tube may be attached to an ordinary burette support and sulphuric acid added until the tube is filled a little above the open- ing into the upper side arm. An Anschuetz thermometer with attached tube containing the slen- der column of solid fat is then immersed in the sulphuric acid until the top of the mercury column is below the opening into the upper side arm. The thermometer may be held in place by a burette support attachment, or by being fitted through a cork placed in the opening of the melting point apparatus. The lower arm of the tube is then slowly heated, by means of a flame, or electrically, from the lowest point to a point about midway between the lowest point and the perpendicular tube. The temperature Tig. 151. Meltingr Point Apparatus. 626 Analysis of Dairy Products should be taken when the fat begins to become translucent and molten and again when it becomes transparent. The best re- sults are obtained when the tube is heated electrically. To accomplish this it is directed that the portion, described above, of the tube to be treated is wrapped with a single layer of thin asbestos paper, and then wound with about 10 turns of michrome wire, No. 26, B and S gauge (about 0.016 in. in dia.). The wire is then covered with a layer of asbestos cement to a depth of about 5 mm. The melting point apparatus may be made of ordinary soft glass, but Pyrex glass is preferable. DETECTING FOREIGN FATS IN MILK FAT. The lower cost of most fats and oils compared with that of milk fat has led to their frequent substitution in a variety of dairy products. This practice gives special importance to methods used in the detection of such substitutes. The fat con- stants that will ordinarily enable the analyst to decide as to the purity of milk fat are (1) the refractive index, (2) the Reichert- Meissl number, and (3) the iodine number. If the evidence ob- tained by determining these constants is not sufficient, a more complete work on fat analysis should be consulted. The figures given in the table that follows indicate the range within which these constants of the edible fats and oils named may be expected to fall. TABLE 105. ' Fat Constants. Refractive Index 25° C. Eeichert-Meisel Number Iodine Number Milk fat Beet tallow Cocoa butter 1.459 to 1.460 1.462* to 1.465 1.462* to 1.464 1.452* to 1.456 1.469 to 1.473 1.463* to 1.467 1.472 to 1.474 1.467 to 1.469 1.468 to 1.471 25 to 34 0.2 to 0.5 0.2 to 0.8 6.0 to 8.5 0.6 to 0.8 0.2 to 0.7 0.7 to 0.9 0.5 to 0.7 0.4 to 0.6 26 to 38 35 to 45 32 to 41 Cocoanut butter 8.0 to 9.5 Cottonseed oil 66 to 77 Lard 54 to 70 Corn oil 79 to 86 Olive oil 77 to 95 reanut oil 83 to 105 * Eeading at 60° C. calculated to 25° C. Rkfractive Index 627 The Refractive Index. Determination with the Abbe Re- fractometer. — The double prism of the instrument is opened by means of the screw head, then place three or four drops of the liquid to be examined on the stationary prism, clamp the prisms together firmly. While waiting for a few minutes to permit the liquid to come to the temperature of the instrument, turn the mirror to properly light the prism. By moving the upright arm Tig, 152. Abbe-Zeiss Refractoiueter. Courtesy Arthur H. Thomas Co. slowly backward and forward, while looking through the sharply focused telescope, a light and dark portion of the field will be observed. The "border line" dividing the light and dark portions of the field is then adjusted until it rests on the point of inter- section of the cross hairs. The refractive index is then read directly to the fourth decimal by looking through the magnifier in the movable arm over the scale. The temperature of the instru- ment at the time the reading is taken should also be recorded. During the determination running water, held at the desired temperature, is allowed to flow through and control the tempera- 628 Analysis of Dairy Products ture of the instrument. The index of refraction may be taken at 25° C, for oils and fats that are liquid at that temperature. For other fats, readings may be made at 40° or 60° C. Determinations by means of the Zeiss-Butyro-Refractometer. — Place 2 or 3 drops of the filtered fat on the surface of the lower prism. Close the prism and adjust the mirror until it gives the sharpest reading. If the reading be indistinct after running water of a constant temperature through the instrument for some time, the fat is unevenly distributed on the surface of the prism. As the index of refraction is greatly affected by temperature, care must be used to keep the latter constant. The instrument should be carefully adjusted by means of the standard fluid which is supplied with it. Convert the degrees of the instrument into refractive indices by use of the table that follows : TABLE 106. Butyro-Refractometer Readings and Indices of Refraction (A). Read- ing Index of Refraction Read- ing Index of Refraction Read- ing Index of Refraction Read- ing Index of Refraction 40.0 1.4524 50.0 1.4593 60.0 1.4659 70.0 1.4723 40.5 1.4527 50.5 1.4596 60.5 1.4662 70.5 1.4726 41.0 1.4531 51.0 1.4600 61.0 1.4665 71.0 1.4729 41.5 1.4534 51.5 1.4603 61.5 1.4668 71.5 1.4732 42.0 1.4538 52.0 1.4607 62.0 1.4672 72.0 1.4735 42.5 1.4541 52.5 1.4610 62.5 1.4675 72.5 1.4738 43.0 1.4545 53.0 1.4613 63.0 1.4678 73.0 1.4741 43.5 1.4548 53.5 1.4616 63.5 1.4681 73.5 1.4744 44.0 1.4552 54.0 1.4619 64.0 1.4685 74.0 1.4747 44.5 1.4555 54.5 1.4623 64.5 1.4688 74.5 1.4750 45.0 1.4558 55.0 1.4626 65.0 1.4691 75.0 1.4753 45.5 1.4562 55.5 1.4629 65.5 1.4694 75.5 1.4756 46.0 1.4565 56.0 1.4633 66.0 1.4697 76.0 1.4759 46.5 1.4569 56.5 1.4636 66.5 1.4700 76.5 1.4762 47.0 1.4572 57.0 1.4639 67.0 1.4704 77.0 1.4765 47.5 1.4576 57.5 1.4642 67.5 1.4707 77.5 1.4768 48.0 1.4579 58.0 1.4646 68.0 1.4710 78.0 1.4771 48.5 1.4583 58.5 1.4649 68.5 1.4713 78.5 1.4774 49.0 1.4586 59.0 1.4652 69.0 1.4717 79.0 1.4777 49.5 1.4590 59.5 1.4656 69.5 1.4720 79.5 1.4780 (A) Winton, Conn. Agr. Exper. Sta. Rpt., 1900, Part 2, p. 143. Reichert-MeiseIv Number 629 The Reichert-Meissl Number. The Reiehert-Meissl number is the number of ee. of tenth-normal alkali required to neutralize the volatile fatty acids distilled from 5 grams of fat when they are set free and the operation is carried out according to specified conditions. The method was developed by Reichert and modified by Meissl. Later Leffman and Beam modified the method slightly rigf. 153. Distilling- Apparatus. by saponifying the fat in a glycerol-soda mixture in place of an alcoholic potash mixture. The Leffman and Beam modification is quite generally used at present. It is carried out as follows : Weigh 5 grams of the pure fat into a round bottomed flask and add 20 ce. of a mixture made by placing 10 cc. of a 50 per cent caustic soda, water solution, in 90 cc. of glycerine. Heat the contents of the flask over a small flame, with constant shaking, until the water is boiled off and the mixture which on boiling had a clouded appearance, becomes clear. Add 135 cc. of water slowly, to prevent foaming and a pinch of pumice stone powder, or a few pieces of pumice stone to prevent bumping during distil- lation. Add 5 cc. of dilute sulphuric acid (200 cc. of concentrated sulphuric acid in 1000 cc. of water). Connect the flask at once to a condenser, shake to mix the acid with the solution and heat to distill off the volatile acids. Distill off 110 cc. at a rate that will yield that volume in 30 to 40 minutes. Filter the distillate through a dry filter and titrate 100 cc. of it with tenth-normal alkali solution. The number of cc. of tenth-normal alkali used multiplied by 1.10 equals the Reichert-Meissl number. 630 Analysis of Dairy Products The Reichert-Meissl number for milk fat is usually between 25 and 32, for cocoanut oil between 6 and 8, and for most other fats and oils less than 1.5. lodin Absorption Number of Fat and Oils. — The capacity of fats and oils to absorb iodin is sometimes used to advantage for the purpose of identifying them or determining their purity. The percentage of iodin that a given fat or oil will absorb under specified conditions is called its iodin number. A method for treating fats and oils with iodin was developed by Hubl.-*^ It was improved and shortened by Hanus and is the method usually employed. The A. 0. A. C. has adopted it as follows : Hanus Method. — Official. — Reagents. — (a) Hanus iodin solu- tion. — Dissolve 13.2 grams of pure iodin in one liter of glacial acetic acid (99.5 per cent) which shows no reduction with dichromate and sulphuric acid. Add enough bromin to double the halogen content as determined by titration (3 cc. of bromin are about the proper amount). The iodin may be dissolved by heat- ing, but the solution should be cold when the bromin is added. A convenient way to prepare the Hanus solution is as follows : Measure 825 cc. of acetic acid which has shown no reduction by the dichromate test and dissolve in it 13.615 grams of iodin with the aid of heat. Cool and titrate 25 cc. of this solution against the N/10 sodium thiosulphate. Add 3 cc. of bromin to 200 cc. of acetic acid and titrate 5 cc. of the solution against the N/10 sodium thiosulphate. Calculate the quantity of bromin solution required exactly to double the halogen content of the remaining 800 cc. of iodin solution as follows : A= — in which C A^cc. of bromin solution required. Br=800 X the thiosulphate equivalent of 1 cc. of iodin solution, C=the thiosulphate equivalent of 1 cc. of bromin solution. Example: — 136.15 grams of iodin are dissolved in 8250 cc. of acetic acid. 30 cc. of bromin are dissolved in 2000 cc. of acetic acid. Titrating 50 cc. of the iodin solution against the standard thiosulphate shows that 1 cc. of the iodin solution equals 1.1 cc. of Iodinb; Numbe;r 631 the thiosulphate (0.0165 gram of iodin). Titrating 5 cc. of the bromin solution shows that one cc. of the bromin solution equals 4.6 cc. of the thiosulphate. Then the remaining quantity of bromin solution required to double the halogen content of the remaining 8200 cc. of iodin solution is equivalent to ' 4.6 or 1961 cc. Upon mixing the two solutions in this proportion, a total volume of 10161 cc. is obtained, containing 135.3 grams of iodin. In order to reduce this solution to the proper strength (13.2 grams iodin per liter), 10.161X13.2=134.1; 135.3—134.1= 1 o f ■ A . ■ 1.2X1000 _^ „ 1.2 grams ot lodm present m excess, or — =91 cc. ot 13.2 acetic acid which must be added. (b). N/10 sodium thiosulphate solution. — Prepare a solution containing 24.82 grams of sodium thiosulphate (Na2S20;55H20) in water and dilute to 1 liter. Standardize this solution as follows : Place in a glass stoppered flask 20 cc. of the N/10 potassium dichromate and 10 cc. of the 15 per cent potassium iodide solution. Add 5 cc. of strong hydrochloric acid. Dilute with 100 cc. of water and allow the N/10 sodium thiosulphate to flow slowly into the flask until the yellow color of the liquid has almost disappeared, add a few drops of starch indicator and, with constant shaking, continue to add the N/10 sodium thio- sulphate until the blue color just disappears. (c). Starch indicator: — Mix about 0.5 gram of finely pow- dered potato starch with cold water to a thin paste ; pour into about 100 cc. of boiling water, stirring constantly, and discon- tinue heating immediately after the paste is added. (d). Potassium iodid solution. — Dissolve 150 grams of potas- sium iodid in water and dilute to 1 liter. (e). N/10 potassium dichromate. — Dissolve 4.903 grams of potassium dichromate in water and dilute to 1 liter. The strength of this solution should be checked against pure iron. Determination. — ^Weigh about 0.500 gram of fat, or 0.250 gram of oil (0.1 — 0.2 gram in the case of drying oils which have a very high absorbent power), into a 500 cc. glass-stoppered flask or bottle. Dissolve the fat or oil in 10 cc. of chloroform. Add 25 cc. 632 Anai^ysis of Dairy Products of the Haniis iodin solution and alloAv to stand for 30 minutes, shaking occasionally. This time must be adhered to closely in order to obtain good results. The excess of iodin should be at least 60 per cent of the amount added. Add 10 cc. of the 15 per cent potassium iodid solu- tion, shake thoroughly and then add 100 cc. of water, washing down any free iodin that may be found on the stopper. Titrate the iodin with N/10 sodium thiosulphate, adding the latter grad- ually, with constant shaking, until the yellow color of the solution has almost disappeared. Add a few drops of the starch indicator and continue the titration until the blue color has entirely dis- appeared. Toward the end of the titration, stopper the bottle and shake violently, so that any iodin remaining in solution in the chloroform may be taken up by the potassium iodid solution. Conduct two blank determinations along with that on the sample. The number of cc. of the sodium thiosulphate solution required by the blank less the amount used in the determination gives the thiosulphate equivalent of the iodin absorbed by the fat or oil. Ascertain the iodin number by calculating the per cent by weight of iodin absorbed. ESTIMATION OF MILK FAT IN MILK CHOCOLATE. A. 0. A. C— TENTATIVE METHOD. Estimate the amount of milk fat in milk chocolate from the following formula based on a Reichert-Meissl number of 0.5 for cocoa butter : 24A+0.5B C= p in which 5 A=grams of butter fat in 5 grams of mixed fat, B=5 — A= grams of cocoa fat in 5 grams of mixed fat, C=Keichert-Meissl number of extracted fat. From which the C— 0.5 Weight of butter fat in 5 grams of mixed fat=r — j-Tj— and the C— 0.5 Per cent of butter fat=per cent of total fatX qq r I Tests for Thickeners . 633 DETECTING GUMS, GELATINIZING AGENTS AND THICKENERS. In recent years a number of substances of colloidal nature have been used to give apparent "body" to a wide variety of food products. Most of them are able to absorb relatively large amounts of water and when mixed with diluted food emulsions impart properties that simulate the richness of the genuine product. Among the substances used are gelatin, sucrate of lime, gum tragacanth, gum arabie (acacia), agar-agar, starch, dextrin, glucose, and pepsin. Methods for detecting their presence in foods and for identifying them have been developed and while not wholly satisfactory serve their purpose fairly well. Patrick's Method for Detecting* Thickeners. — Add 25 cc. of water to 50 cc. of the sample and heat to boiling to dissolve thickeners that may be present, add 2 cc. of 10 per cent acetic acid, heat again to boiling and add 3 heaping tablespoonfuls of kieselguhr, mix thoroughly and pass, without delay, through a plaited filter. Add 12 cc. of 95% alcohol to 3 cc. of the clear filtrate and mix. This precipitates any of the milk proteids remaining, also the gums and some of the gelatin if much is present. To dissolve the milk proteids add 3 cc. of a mixture containing 5 cc. of concentrated hydrochloric acid in 95 cc. of 95% alcohol. If a clear liquid is obtained no gums or vegetable jellies are present, and turbidity or a precipitate does not necessarily indicate the presence of a thickener, as it may result from the use of eggs or the gelatin used in ice cream as a stabilizer. Add 3 cc. of water, if the mixture is turbid at this dilution any precipitate due to gelatin or eggs will be dissolved, a stringy and cohesive precipitate, especially after shaking, shows the presence of gum tragacanth, while agar-agar and other vege- table thickeners give a finely flocculent precipitate devoid of stickiness. When sour cream containing no thickeners is tested an insoluble precipitate may form and which does not dissolve when water is added. By adding formaldehyde to the sample while it is sweet, it appears that the formation of such a precipi- tate may be avoided. Cong-don's Method-" for Detecting Thickeners and Similar Agents in Foods. — By this method the thickening materials are separated into six groups on the basis of reagents used. The reagents are added to the water soluble solutions of the materials 634 • Analysis of Dairy Products to obtain the reactions. While specific directions for applying the method to dairy products are not given in the original article the following table should be of assistance in identifying the different substances. — "Group 1. — Group reagent — Iodine solution. Blue coloration indicates starch. (Sometimes green apples made into jelly will give traces of starch.) Purple coloration indicates Amylo-dextrin. Red coloration indicates Erythro-dextrin. No coloration may indicate neither starch nor dextrin, but may be Achro- dextrin. Group II. — Group reagent — Million's or Stokes' reagent (acid nitrate of mercury). Mixture, after shaking substance in solution with reagent, is cloudy, Yellow precipitate with picric acid solution indicates Gelatin. Drop of this reagent. Gelatinous precipitate, soluble in excess of this reagent, indicates Acacia. A slight white cloudy precipitate may indicate either Agar -agar or Tragacanth or both (test for Tragacanth as in gi'oup IV). Group III.- — Group reagent — Concentrated solution of sodium borate. A white gelatinous precipitate indicates either Agar -agar or Acacia or both. Acacia will give a gelatinous, opaque white precipitate with solution of basic lead acetate. Acacia may be further tested for as in Group II or Group IV or by adding a solution of tannin which gives a bluish black coloration. Group IV. — Group reagent — Solution of sodium hydrate. A brownish yellow color on heating indicates Tragacanth. A white cloudy precipitate indicates Acacia. Group V. — Group reagent — Solution of mercuric chloride. A slight turbidity may indicate Dextrin. A white precipitate may indicate Albumin and Gelatin. Group VI. — Group reagent — Schweitzer's reagent (solution of cupra-ammonia). If a concentrated water solution of the unknown is treated with this reagent and placed on glass slide under microscope, a delicate framework of cupric pectate is evident, showing a pectin of fruit or vegetable origin present." Cook and Woodman's Method-* for the Detection of Vegetable Gums in Food Products. — In this method the tests are applied to the gums after they have been separated, in a relatively pure condition, from 50 to 200 grams of the sample as the ease may Tests for Thickeners 635 require. The proteins in the food mixture are precipitated by adding acetic acid and tannin, heating and filtering, then the gums are precipitated from the filtrate by the addition of acetone. The filtrate contains the sugars and other acetone soluble ma- terial. Soluble phosphates, derived from sources like milk, are removed by an extra precipitation with ammonia. Finally the guqis are redissolved and precipitated relatively pure by alcohol. In order to use the method successfully, before making a test on an unknown, the analyst should become familiar with the appearance and characteristic properties of the various gum TABLE 107. The Separation of Gums. A — Elimination of Proteins. 1 — Dilute sample to suit- able c o n c e n tration with water, add 5 cc. dilute acetic acid and 35 cc. of 10 per cent tannin solution, and heat mixture for 20 to 30 minutes. Centri- fuge and filter. Dis- card precipitate. Note — Casein, coagulable proteins, and some of the gelatin precipi- tated. Fats and other insoluble substances included in precipi- tate. 2 — Add 40 to 50 cc. more tannin solution to fil- trate from Al and heat for a short time. Centrifuge and filter. Discard precipitate. Note — Remainder of gel- atin and soluble pro- teins precipitated. B — Separation of Gums and Dextrin from Sugars. 1 — Treat clear filtrate from A2 with twice its volume of acetone. Centrifuge and filter. Discard filtrate. Wash precipitate twice with acetone. Note — Precipitate in- cludes gums and dex- trin. No precipitate shows absence of gums, dextrin, and milk solids. 3 — Dissolve precipitate from Bl in 50 cc. of warm water slightly acidified with acetic acid and add 10 cc. of ammonia (sp. gr. 0.90). Centrifuge and filter. Discard pre- cipitate. Note — Calcium phos- phate from milk solids precipitated. -Isolation of Pure Gum Substance. Add acetic acid to filtrate from B2 until slightly acid. Add alcohol, one volume at a time, un- til a well defined pre- cipitate appears. Note — Gums and dextrin precipitated in a fair- ly pure condition. No precipitate with 5 volumes of alcohol in- dicates absence of gums and dextrin. 636 Analysis of Dairy Products precipitates by working on their solutions. The procedure is summarized in the following table: TABLE 108. Identification of Gums. Approximate Volumes of Alcohol Necssary for precipitation Characteristic Appearance of Gum Precipitate Characateristics of Gum Precipitate After Standing for Some time in Air. Vols. Al- cohol Vol. Gum Solution Agar ..3-4 Arabic ... 2 Indian .3-3 Traga- canth ... 2 Dextrin . . 3 1 1 1 1 1 Finely divided white pre- cipitate; settles very slowly. Wliite flocculent precipi- tate; settles quickly; neither sticky nor co- herent. Stringy precipitate; be- comes very coherent after settling. Coherent, jelly-like mass; floats in clots in upper part of solution. ■Wliite, fine precipitate, settles slowly; very sticky. Usually remains soft and non-coherent. Becomes dry and powdry. Becomes dark colored; tough coherent layer. Flattens down, becoming a semi-transparent co- lierent layer. Tends to become hard on long standing. It is claimed that, by the above procedure, amounts of gum as small as 0.1 per cent can be separated from ordinary food mixtures, but some gums are more readily detected than others. Tragacanth is easier to detect than either gum arable or agar. Where the ratio of protein, and possibly some other precipitable matter is large there is danger of the gums bing carried down mechanically and lost. Where more than one gum is present, and in mixtures con- taining pectin and commercial glucose, the identification of the gum is made more difficult. Sucrate of Lime in Milk and Cream.— Sucrate of lime (visco- gen) is sometimes added to cream in order to increase the viscosity, a quality that indicates richness. Determinations of Lime De;terminations 637 (1) the presence of sucrose, (2) the alkalinity of the water-soluble ash, (3) the alkalinity of the insoluble ash, and (4) the lime content may assist in detecting its presence. Sucrose may be detected by means of Lythgoe's modification-" of Baier and Neuman's test. The test is made according to the following directions : Add 10 cc. of a 5 per cent solution of uranium acetate to 25 cc. of the sample, shake thoroughly, let stand for five minutes and filter. To 10 cc. of the filtrate (or all of it if less than 10 cc.) add a mixture of 2 cc. of saturated ammonium molybdate solution and 8 cc. of dilute hydrochloric acid (1 cc. of 25 per cent acid in 7 cc. of water) and place in a water bath at a temperature of 80° C. for 5 minutes. The solution will have a prussian blue color if sucrose is present. A comparative test should be run in like manner on a pure sample. The latter will sometimes give a pale blue color. Alkalinity and Calcium Determinations. — Weigh into a plati- num dish 25 grams of the sample, evaporate to dryness in a water bath, char and burn at a temperature so low that the fat will scarcely flame until it is burned off, then at a little higher temperature but not above a barely preceptible red until all of the carbon has disappeared and the ash is almost white. Cool in a desiccator and weigh. To determine the alkalinity of the soluble ash add 25 cc. of water and heat nearly to boiling, filter through an ashless filter, wash with 25 cc. of hot water, dry the filter and contents and burn to a white ash. Weigh to obtain the insoluble ash, and subtract its weight from the total ash to obtain the weight of the soluble ash. To determine the alkalinity of the water-soluble ash add 20 cc. of N/10 hydrochloric acid to the filtrate containing the soluble ash, heat nearly to boiling to expel carbon dioxide, cool, add a few drops of phenolphthalein indicator solution and neutralize the excess of hydrochloric acid with N/10 alkali. Determine the cc. of N/10 hydrochloric acid to neutralize the soluble ash, then calculate and record the result on the basis of 100 grams of the sample. To determine the alkalinity of the insoluble ash place 25 cc. of N/10 hydrochloric acid in the dish containing it and heat 638 Analysis of Dairy Products cautiously nearly to boiling, cool and neutralize the excess of hydrochloric acid with N/10 alkali, using phenolphthalein as indicator. Calculate the cc. of N/10 acid required to neutralize the ash and report the result as in the determination for the alkalinity of the soluble ash. The total ash alkalinity of 100 grams of cream containing between 25 and 33 per cent of fat requires between 14 and 20 cc. of N/10 acid calculated to 100 grams of sample. To determine the calcium. — Mix the neutral liquids from the soluble and insoluble ash, add 20 cc. of dilute hydrochloric acid, neutralize with ammonia, add one gram of ammonium chloride and an excess of ammonium oxalate. Boil for three or four minutes, filter through an ashless filter and wash with water. Dry the filter with the precipitate, burn the filter, allowing the precipitate and ash to fall into a weighed platinum crucible. Heat gently at first and then for 10 minutes at a very dull red. Avoid over heating, as some of the calcium carbonate may be converted to the oxide. Cool in a desiccator and weigh. From the weight of calcium carbonate obtained calculate the weight of calcium oxide. The maximum amount of calcium oxide in milk should not exceed 0.212 per cent. In cream, as the percentage of fat in- creases, the percentage of calcium oxide decreases. The maximum percentage of calcium oxide that is likely to be obtained from pure cream may be calculated by applying the formula: (100— F\ — fr\(\ — / F=the per cent of fat in the cream. A METHOD FOR ANALYZING SALT.^ Tests for Insoluble Matter. — After sampling well reduce the salt to a fine powder, and put into a glass-stoppered bottle. "Weigh out 10 grams of this powder and dissolve in a beaker by digestion Avith hot water and filter the solution into a 500 cc. graduated flask. Wash the residue thoroughly, taking care that the residue contains insolubles only and not grains of the slowly soluble calcium sulphate. Fill the flask up to the mark with Sai,t Analysis 639 distilled water, mix well and set aside for later determina- tions. Ignite and weigh the insoluble residue. This weight multi- plied by 100 and divided by the weight of the sample (10 grams) gives the per cent of insoluble matter. Test for Calcium: — Remove 150 cc. of the salt solution from the 500 cc. flask with a pipette and add a small quantity of ammonium chloride and a slight excess of ammonium hydroxide. The solution should be clear at this point, if not, more ammonium chloride should have been added. A considerable excess of ammonium oxalate solution is now added and the solution allowed to stand for some time, after which it is filtered and the residue washed well. The precipitate of calcium oxalate contains a slight amount of magnesium at this point and for a complete separation must be redissolved with hydrochloric acid, made alkaline with ammonium hydroxide and reprecipitated with ammonium oxalate. The calcium oxalate precipitate is then dissolved from the filter paper with 150 cc. dilute sulphuric acid and the paper washed well. About 6 or 8 cc. of strong sulphuric acid is then added and the solution warmed to 60^ centrigrade and titrated with potas- sium permanganate solution to a slight pink color. The solution should be stirred during the titration. In order to obtain the percentage of calcium without calculation the potassium per- manganate solution should be made up by dissolving 0.5254 gram of chemically pure potassium permanganate in one liter of dis- tilled water accurately measured. It is best to make up at least five liters of this solution and use an automatic burette if very much work is to be done. Each 10 cc. of this solution will be equal to 1% calcium with the above method. The potassium permanganate solution should be kept in a brown bottle or a bottle painted black. It is well to check the solution from time to time against a weighed sample of chemically pure sodium oxalate. Thirty cubic centimeters of the potassium permanganate solution will consume 0.03342 gram of the sodium oxalate. It is easier to weigh a larger quantity of the salt and several checks should be made at a time, so it is best to dissolve 0.3342 gram of sodium oxalate in 500 cc. of distilled water and take several portions of 50 cc. each. Titrate this with the permanganate solution after adding 5 or 6 cc. of strong sulphuric acid and warming to 60° Centigrade. If the permanganate is 640 Analysis of Dairy Products found to be too weak it can be strengthened by adding a little of a stronger solution. Test for Magnesium : — The combined filtrates from the calcium determination are acidified, evaporated to about 100 cc, 30 cc. of strong ammonia and 25 cc. of 10% solution of sodium arsenate added. This is best done in an Erlenmeyer flask, so that the solution may be vigorously shaken after the reagents have been added. The precipitate is filtered off, washed with the least possible amount of dilute ammonia, dissolved in 25 cc. dilute sluphuric acid (1 to 4) into the original flask. The filter is washed with 50 cc, hot water and 10 cc. sulphuric acid (1 to 1) added. After cooling, 3 to 5 grams of potassium iodide are added, the solution allowed to stand for five minutes, then the liberated iodine titrated with sodium thiosulphate solution to a faint straw color. A few cubic centimeters of starch solution are then added and the titration completed to a colorlessness. The standard sodium thiosulphate solution should be made up of 6.7863 gm. of chemically pure sodium thiosulphate crystals (Na2S203.5HoO.) per liter. Ten cubic centimeters of this solution is equal to 1% magnesium. Standardize this solution against 50 cc. samples of a solution of 0.4942 gm. of chemically pure magnesium sulphate crystals in 500 cc. of distilled water treated as for the analysis of magnesium. It should take exactly 30 cc. of the standard sodium thiosulphate solution to titrate these samples. The starch indicator solution is made by mixing 1 gm. of starch to a paste in a little cold water and then gradually pouring this into 200 cc. of boiling water. This solution should be boiled a little and put into a glass stoppered bottle with a few drops of chloroform when cool. Test for Sulphate. — A sample of 100 cc. of the original salt solution is transferred to a 250 cc. beaker, made very slightly acid with hydrochloric acid, heated to boiling and an excess of barium chloride solution containing about 100 gms. of the salt per liter is added while rapidly stirring the solution. After allowing to stand a few moments the barium sulphate is filtered off on an ashless filter and M^ashed well with water. The filter containing the precipitate is then placed in a weighed porcelain or platinum crucible and ignited, cooled and weighed. VaniiOH~). (3). A solution is alkaline when the number of free hydrogen ions is less than that of the free hydroxjd ions (H+ '^'Z'Z^ OOrf (M ^ OO OQ OOO O 8 OOO oooo SOOQ OOO OOQO OOOO OOOO OOOO oooo OOOO •> s X 00 ^ (M ^ OOOO X" " ^ 00-* (^^ ' OOOO X" " " 00-^ (M — < X i^^ X" - - 00 -^i (N ' K ^ Tjtl^O « "* t^O ^ -^ t^ o ^-^ t^o Hydrogen Ion Concentration 671 H go la OS M o :2 S O^ o o o< o o o < o o O ! ooo< X^ (N lO O O •-i (M lO O oo OQ OO ^>. o o o o oo X" lO O O Q (M lOO O T-H (M LO O 00 00 00 O) (M lO ^ 5^ ^ (M 10 '^ 0000 0000 0000 X^ lOOOO • ooo"-^ 0000 0000 lO ^ -i ■<}< t>. dd d x- ^ " oo-* C^ — I X" - " 00-^ IM r-l ddddi X ^ " 00 ■* (N ^ ddididi X 00 -^ (N 1-1 d>d>d>d> X 00 ■* c^ ^ 00 -^IM ^ dood t>^t>^t>^o6 1— C^ £>. O odooood 000^0 -H Tj< t^ o i -^ ^ c\i (M (N (N fO 672 Analysis of Dairy Products concentrations of solutions can be brought out more clearly by the following illustrations, using HCl and NaOH and assuming that they are completely ionized. TABLE 116. pH Values HCl Concentrations Expressed pH Values NaOH Concentrations Expressed Decimally Fractionally Decimally Fractionally .IN N To 8 .000,001 N N 1.0 1,000,000 .04 N N 25 9 .000,01 N N 1.4 100,000 1.7 .02 N N 50 10 .0001 N N 10,000 .01 N N 100 11 .001 N N 2.0 1,000 2.1 .08 N N 125 11.1 .00125 N N 800 2.4 .004 N N 250 11.4 .0025 N N 400 2./ .002 N N 500 12.0 .01 N N 100 b.O .001 N N 12.1 .0125 N N 1,000 80 4.0 .0001 N N 12.4 .025 N N 10,000 40 5.0 .000,01 N N 100,000 12.7 .05 N N 20 6.0 .000,001 N N 1,000,000 13.0 .1 N N 10 In Table 117 we give the pH values and their equivalent C values for each 0.01 pH, ranging between 1 and 2. By the use of this table one can readily ascertain values intermediate be- tween those given in Table 116. These intermediate figures can be used for any part of the range of values given in Table 116 by Hydrogen Ion Concentration 673 adapting the decimal properly. By the use of Tables 116 and 117 in combination, one can convert pH values into Ch values, or vice versa, simply by inspection and without calculation. TABLE 117. Inteimediate pH and Cjj Equivalents for Use with Table 116. pH Values C Values pH Values C Values pH Values c Values pH Values C Values pH Values C Values 1.00 .1000 1.20 .0632 1.40 .0400 1.60 .0251 1.80 .0159 1.01 .0980 1.21 .0619 1.41 .0392 1.61 .0246 1.81 .0156 1.02 .0959 1.22 .0606 1.42 .0384 1.62 .0241 1.82 .0152 1.03 .0939 1.23 .0592 1.43 .0375 1.63 .0236 1.83 .0149 1.04 .0918 1.24 .0579 1.44 .0367 1.64 .0231 1.84 .0146 1.05 .0898 1.25 .0566 1.45 .0359 1,65 .0226 1.85 .0143 1.06 .0877 1.26 .0553 1.46 .0351 1.66 .0220 1.86 .0139 1.07 .0856 1.27 .0540 1.47 .0343 1.67 .0215 1.87 .0136 1.08 .0836 1.28 .0526 1.48 .0334 1.68 .0210 1.88 .0133 1.09 .0815 1.29 .0513 1.49 .0326 1.69 .0205 1.89 .0129 1.10 .0795 1.30 .0500 1.50 .0318 1.70 .0200 1.90 .0126 1.11 .0779 1.31 .0490 1.51 .0311 1.71 .0196 1.91 .0123 1.12 .0762 1.32 .0480 1.52 .0305 1.72 .0192 1.92 .0121 1.13 .0746 1.33 .0470 1.53 .0298 1.73 .0188 1.93 .0118 1.14 .0730 1.34 .0460 1.54 .0291 1.74 .0184 1.94 .0116 1.15 .0714 1.35 .0450 1.55 .0285 1.75 .0180 1.95 .0113 1.16 .0697 1.36 .0440 1.56 .0278 1.76 .0175 1.96 .0110 1.17 .0680 1.37 .0430 1.57 .0271 1.77 .0171 1.97 .0108 1.18 .0665 1.38 .0420 1.58 .0264 1.78 .0167 1.98 .0105 1.19 .0648 1.39 .0410 1.59 .0258 1.79 .0163 1.99 .0103 1.20 .0632 1.40 .0400 1.60 .0251 1.80 .0159 2.00 .0100 There are two points in connection with the determination of hydrogen ion concentration to which it is desirable to call atten- tion briefly: (1) Buffer effects and (2) the relation of hydrogen ion concentration to titration values. (1) Buffer effects. It has been found that many compounds have the property of affecting the results of the determination of the hydrogen ion concentration. When acid or alkali is added to a solution containing such compounds, the change in hydrogen ion 674 Analysis of Dairy Products concentration is found to be less than would be expected for the known amount of acid or alkali added. Any substance which tends to prevent change in the original hydrogen ion concentra- tion of its solution, when an acid or base is added, is called a buffer or regulator. Proteins, salts, etc., may exercise such an effect. These effects must be determined for individual cases under specific conditions of concentration, temperature, etc. In tlie case of milk, the compounds acting as buffers are proteins, phosphates, citrates and carbonates. (2) Relation of hydrogen ion concentration to titration values. We have seen that hydrogen ion concentration is a quan- titative measure of the true acidity or alkalinity of a solution. The following question suggests itself to those who have used only titration methods for such measurements : What relations have the values determined by the measurement of the hydrogen ion concentration to those determined by titration? Without going into the full details, it is sufficient for our purpose to state that the neutral point of a solution, as determined by the use of an in- dicator, varies according to the indicator used and rarely coin- cides with the true neutral point shown by the hydrogen ion con- centration. For example, phenolphthalein under favorable con- ditions gives the neutral point of solutions as being somewhere between pH, 8 (Ch, IXIO-') and pH, 10 (Ch, IXIO-^), instead of at pH, 7 (Ch, lXlO-«) ; methyl red, between pH, 4(Ch, IXIO-') and pH, 6(1X10-5). It should be stated also that the determina- tion of hydrogen ion concentration shows extremely minute changes in the reaction of a solution, degrees of change which are not appreciable or measurable by the use of an indicator. ELEGTROMETRIC TITRATIONS OF SOLUTIONS CONTAINING PROTEIN. Before attempting hydrogen ion concentration determina- tions upon which conclusions of importance may be based the operator should consult the available literature on the subject, and by study and experiment become, as far as possible, familiar with methods and the many conditions and influences that are likely to affect results. This should be done no matter which Hydrogen Ion Concentration 675 method is used. The nature of the interferences will vary accord- ing to the problem but there is now available a large amount of material that may serve as a guide. The book, "The Determina- tion of HA^drogen Ions,*' by Clark, is one that no worker should fail to consult. Baker and Van Slyke's Method. — This method provides a means for making electrometric titrations of solutions containing Tig. 159. Apparatus foi* Making' Electrometric Titrations of Solutions Containing' Protein. proteins which is shorter and less complicated than methods pre- viously used. A cut of the apparatus used in the test is shown in Fig. 159. It consists of a 400 cc. wide mouthed bottle (V) calibrated in units of 50 cc. and provided with a cork stopper (S) which is divided into two equal halves that may be easily ad- justed in the neck of the bottle. The tube (E) for carrying the hydrogen electrode, and through which hydrogen may be passed into the bottle, is made by cutting a 10 cc. pipette in two in the 676 AnaIvYsis of Dairy Products middle, then cutting one side of the lower edge off diagonally. The upper end of the tube is fitted through a hole in the stopper so that it may be raised and lowered as desired. A close fitting piece of pure gum rubber tubing attached to the upper end of the glass tube permits hydrogen to be passed into the apparatus when necessary. The hydrogen electrode (A) is about 1 cm. square and is made from platinum foil and welded to a piece of platinum wire about 15 cm. long. A slender piece of glass tubing extending down close to the electrode and annealed at each end around the wire covers the lower half of the wire. The upper end of the platinum wire is passed through a pin hole made through one side of the rubber tube after bending it across the top of the hydrogen tube. This makes a gas tight joint that permits the hydrogen electrode to be raised and lowered within the bell shaped lower end of the hydrogen tube and avoid having the electrode touch the inside wall. The electrode is prepared for use by cleaning it in hot chromic acid, washing with water, then giving it a uniform coating of platinum black. It is again dipped in hot chromic acid, washed and electrolyzed according to Clark's directions *\ All points on the electrode should give off bubbles with equal uniformity. The titration reagent is carried into the solution, from a bur- ette 30 cm. long and holding 10 cc, by means of the capillary glass tube (B). The capillary tube should fit snugly in the hole through the cork. The stirring apparatus (D) is the same as that described in Fig. 158, page 661. The opening through the cork should be just large enough to permit the rod to revolve freely. The tube (C) permits the addition of any special reagent, such as caprilic alcohol when necessary to prevent foaming. It may also serve, when made long enough, to siphon off a solution. It should then be located near the side wall away from the stirrer. The tube (K) contains saturated KCl solution. A roll of filter paper is placed in the small opening in the tip that enters the protein solution, and also, the upper surface of the KCl solution in the funnel is held slightly below the level of the protein solution in the bottle, in order to retard flow and diffusion. When the ap- paratus is used with a water bath the stop-cock in the KCl tube may be placed near the rubber connection at the top. Hydrogen Ion Concentration 677 The folloMdiig additional pieces of apparatus are used: (a) A Leeds and Northrup potentiometer, type K; (b) a Leeds and Northrup galvanometer, type R, for zero instrument; (c) a one cell storage battery to supply the working current, which is checked with a Weston standard cell kept at constant tempera- ture. The current being measured originates in the chain, Hg|HgCl|0.1 N KC1| solution|Ho|Pt,|kept at constant temperature during each titration. Operation. The solution to be titrated is poured into the bottle or vessel (V) and water is added to make the desired volume. If a thermostat is used, the temperature of the solution should now be adjusted. Any bubbles present should be removed, which can be done by pricking them with a greased pin or by touching them with a fine capillary tube containing ether. The burette must be previously filled and all bubbles carried out of the delivery tube (B), the tip of which should be rinsed before it is put into the vessel. The filled delivery tube and the stirrer are placed in position within the vessel or bottle. The two halves of the cork stopper are placed in position together with the other parts. Care is taken to have the electrode drawn up within the protecting bell so that it does not touch the apparatus or solu- tion. Hydrogen is now permitted to flow rapidly in until the air is displaced, after which the stirrer is set in motion. This precau- tion is necessary because any bubbles of air that are stirred into the solution greatly retard the attainment of equilibrium. The electrode is now quickly lowered until it is entirely under the surface of the solution, and connections are then completed for the electrolytic circuit. Equilibrium is quickly reached ordi- narily, usually in 2 to 5 minutes after introducing the electrode. During the period approaching equilibrium, the stirrer should be run fast enough to kep a few bubbles of hydrogen constantly in suspension in the solution. Equilibrium is indicated by a con- stant E. M. F. for 2 minutes or more. When the E. M. F. is satisfactory, the desired amount of reagent is slowly introduced from the burette, during which the stirrer may be slightly ac- celerated to prevent coagulation but not fast enough to produce foam. After introduction of the reagent, readings are made once a minute until constant. When the amount of reagent introduced 678 Analysis of Dairy Products is 0.5 cc. or less, equilibrium should be immediate. Titration is now continued until the desired number of values is obtained. In order to avoid marked dilution of the protein solution, titra- tions are made with use of N solutions of reagents, and thus the need of making corrections is avoided since the hydrogen ion concentration of the buttered solutions is inappreciably changed by the small degree of dilution under such conditions. The speed of the stirrer must be carefully regulated so as to cause little or no foam ; consequently, the addition of the reagent must be mod- erately slow; for example, about 1 cc. in 2 minutes in the ease of N HCl with solutions containing 1 per cent of casein. The accuracy of the electrometric titration can be checked, when completed, by redetermining the final E. M. F. value of the titration of the solution with a Clark electrode. If agreement is not close, the results of the titration should be discarded and the operation repeated. In our work agreement is nearly always ob- tained. Baker and Van Slyke's Colorimetric Method^" for Determin- ing' Hydrogen Ion Concentration in Milk: Preparing the indi- cator: Dissolve finely ground crom-cresol purple in water using 0.1 g. for 100 cc. of water. Heat on a water bath to hasten solu- tion to saturation. Cool to room temperature and filter. The saturated solution contains about 0.09 per cent of the dye. Apparatus: (a) A burette with delivery so controlled that each drop measures 0.05 cc. of indicator, (b) Test tubes made of Pyrex glass, flat-bottomed, and about 4 inches long and Yz inch in diameter. The tubes hold about 8 cc. and should be uniform in color and thickness of wall, (c) Test tube rack so constructed that the tubes may be held in a line side by side without conceal- ing any of the milk column, (d) Pipettes graduated at 3 cc. for measuring the milk into the test tubes. Operation: Place the test tubes in the holder, fill the burette with the brom-cresol solution and adjust the stop-cock to deliver about 1 drop in 2 seconds, each drop measuring 0.05 cc. Allow 1 drop of the indicator to flow from the burette into each tube without touching the side walls while it is falling. Place 3 cc. of milk from the first sample in the first tube. Mix the milk thor- oughly Avith the indicator, then measure 3 cc. of the second sample Hydrogen Ion Concentration 679 into the second tube, mix and proceed in a similar way for all samples. Compare the shade of color obtained with each sample with a color standard made up as follows : Select a sample of normal milk containing between 3 and 4 per cent of fat and having an acidity that requires nearly, but not more than, 1.8 cc. of tenth- normal alkali for 10 cc. of the milk, using 0.5 cc. of a neutral alco- holic phenolphthalein solution as indicator. Arrange 8 test tubes and place 10 cc. of the normal milk in each. Run tenth-normal NaOH solution into them as follows : Tube No 1 2 3 4 5 6 7 8 Drops of tenth-normal NaOH... 2 4 6 8 10 12 14 In addiiig the alkali from the burette take all of the precau- tions that were observed in measuring the brom-cresol purple into the first set of test tubes. Mix the alkali and milk thoroughly. Arrange another set of 8 test tubes like the smaller ones used in the first instance and number them from 1 to 8, From each test tube containing the milk and alkali mixture measure 3 cc. into the smaller test tube that is numbered correspondingly, and add to each, one drop of the brom-cresol purple solution and mix well. Compare the color of each tube containing the unknown milks with the standard set of tubes containing the milk, alkali and brom cresol mixture. The reaction color in each tube corresponds approximately to the following pH values. TABLE 118. No. in series 1 2 3 4 5 6 7 8 cc. of 0.1 N NaOH used.. 6.5 to 6.6 0.1 6.6 to 6.67 0.2 6.67 to 6.75 0.3 6.75 to 6.82 0.4 6.82 to 6.90 0.5 6.90 to 6.98 0.6 6.98 to 7.05 0.7 7.05 to 7.13 Symbol for reaction color N N-1 N-2 N-3 N-4 N-5 N-6 N-7 As a matter of convenience in tabulating results, we append a series of symbols to indicate the pH values, N standing for nor- 680 Analysis of Dairy Products mal reaction and N followed by the minus sign and figures rang- ing from 1 to 7, indicating decreased acidity corresponding to increasing pH values. Such samples as appear to be abnormal by showing a deeper blue shade of color, indicating decreased acidity, are open to the suspicion of being watered, or skimmed, or treated with alkaline salts, or containing excessive numbers of leucocytes as in milk from diseased udders. Which of these suspicions is justified can be ascertained by the determination (1) of the freezing-point, (2) of the percentage of milk-fat or the ratio of fat to proteins, (;}) of the specific gravity, (4) of the total solids, (5) of the presence of alkaline salts, especially sodium bicarbonate and borax, (6) of the numbers of leucocytes by direct microscopic examination by Breed's method, and (7) of COo by Van Slyke's method*' modi- fied by us for use in connection with milk. In the case of samples showing a color lighter than normal with the brom-cresol purple solution, indicating an abnormal de- gree of acidity, there is awakened the suspicion of bacterial acid production, the presence of formaldehyde, overheating, or the presence of added acid salts ; or tlie lighter color may be due to a high percentage of milk-fat. Which of these indications is correct is determined as follows : A direct count of the number of bacteria is often sufficient. If this fails to show the presence of excessive numbers of bacteria, then a test should be made for the presence of formaldehyde, and if this is not present, the percent- age of milk-fat is determined ; and, further, in order to see if the light color is due to overheating, the determination of carbon dioxide should be made and Storch's test may also be applied. McCrudden's^'' Colorimetric method for determining" hydrogen ion concentration. — This method is primarily for use in bacterio- logical work. Standard solutions: Prepare "tenth molecular solutions of KH.PO4 (13.62 grams potassium phosphate, monobasic, anhy- drous, Merck's reagent, to the liter) and Na^.HPO^ (14.21 grams sodium phosphate, anhydrous, Merck's reagent, per liter). From these the following twelve standard solutions are prepared: Hydrogen Ion Concentration TABLE 119. pH of Phosphate Solution. 681 M M c. c. JO c. C. J^ pH Na,HPt), KH,PO, 8 93 5.8 12 88 6.0 19 81 6.2 27 73 6.4 37 63 6.6 49 51 6.8 61 39 •7.0 73 27 7.2 82 18 7.4 89 11 7.6 94 6 7.8 97 3 8.0 The Reading. — To determine the hydrogen ion concentration of an unknown solution coming within the limits of Ph=6.8 to 8.2, add to it five drops of a 0.03 per cent solution of phenol red and compare the resulting color with that obtained by adding the same amount of indicator to 5 cc. of each of the standard phosphate solutions diluted with 10 cc. of water. Between the limits Ph= 5.8 to 6.8 the indicator brom-cresol purple- — five drops of a satur- ated solution — should be used. (The standard solutions with in- dicator in them will keep several weeks if tightly stoppered.) The Comparator. — The color comparison can be made in large clear glass test tubes. To overcome the effect of turbidity, such as occurs in bacteriological media, the unknown solution is di- luted to a moderate extent, say to three times its volume, and the test tubes are arranged in a device called a comparator. The device consists of a block of wood containing 6 perpendicular holes large enough to carry the test tubes. Three other holes are then bored horizontally through the block from side to side, so that one can look right through each pair of test tubes in series. When the solutions are arranged as indicated in each case the light reaching the eye has passed through solution containing indicator and solution containing turbidity. In the case of the unknown, one solution contains both turbidity and indicator; in the case of the standards the turbidity and indicator are in sepa- rate solutions. 682 Analysis of Dairy Products Adjusting reaction of culture media. Most bacteria grow best in media whose pn lies between 7.2 and 7.6. To adjust media to any desired hydrogen ion concentration N/10 alkali is added drop by drop to five cc. of the somewhat diluted media containing in- dicator until, as shown by comparison with the standards, the desired hydrogen ion concentration is reached. From the amount of alkali required for five cc. the amount needed for the whole batch of media can then be calculated. Sterilization of the media shifts the pn about 0.2 toward the acid side. Allowance should be made for this. Clark and Lubs Table.^" Eange pH Thymol blue (acid range) 1.2 — 2.8 Thymol blue (alkaline range) 8.0 — 9.6 Brom phenol blue 2.8 — 4.6 Methyl red 4.4—6.0 Propyl red 4.8 — 6.4 Brom-cresol purple 5.2 — 6.8 Brom-thymol blue 6.0 — 7.6 Phenol red 6.8 — 8.4 Cresol red 7.2 8.8 Cresol phthalein 8.2 — 9.8 The indicators in either powdered form or stock solution may be purchased from chemical supply houses. Thymol blue may be made up for use in .04% solution. Its color change is from red to yellow in the acid range and from yellow to blue in the alkaline range. Brom-Phenol blue is made up to .04%^ solution. Its color change is from yellow to blue. Methyl red is made up to .02% solution. Its color change is from red to yellow. Brom-cresol purple is made up to .04%; solution. Its color change is from yellow to purple. Brom-thymol blue is made up to .04% solution. Its color change is from yellow to blue. Phenol red and cresol red are made up to .02% solutions. Their color change is from yellow to red. Cresol phthalein is made up to .02% solution. Its color change is from colorless to red. References 683 REFERENCES. lU. S. Dept. of Agri., Bui. 134, 1911. 2 M'clnerney, Prof. T. J., Cornell Univ., Ithaca, N. Y. ' Association of Official Agricultural Chemists. * Walker, W. O. A Rapid Method for Determining the Percentage of Casein in Milk. Jour. Ind. Eng. Chem. Vol. 6, No. 2, 1914. 5 Hart, E. B., A Simple Test for Casein in Milk and its Relation to the Dairy Industry, Wis. Exp. Sta. Bui. 156, 1907. " Butterman, S. The Influence of the Method of Manufacture on the Use of Casein in Glue Making. Jour. Ind. and Eng. Chem., Vol. 12, No. 12, p. 141, 1920. '' Dahlberg, A. O. The Manufacture of Casein from Buttermilk or Skim- milk. U. S. Dept. of Agri. Bui. No. 661, Bu. Ani. Ind. 1918. 8 Van Slyke, L. L. N. T. Agri. Exp. St. Bui. 215, 102. * White. W. B., Chemist, Ithaca Laboratory, Division of Foods and Mar- kets, N. Y. Unpublished results, Cornell University. i" Analyst, 1910, 29, 248. " Bigelow and McElroy. Jour. Am. Chem. Soci. 15, p. 668. 1- Rothenfusser. Zeitz. Nahr. Genussm., 16, 51, 1906. 1" Compt. rend, de I'Acad. des Sciences, vol. CXXXIV, p. 1592. " Supplee, G. C, Bellis. B., Citric Acid Content of Milk and Milk Products J. Biol. Chem. 48, 2, 1921. 15 Beau M. (Revue Generale du Lait, 1903-4 P. 385) as modified by Dobbte. (Reports of the Local Gvt. Board on Public Health and Medical Subjects. New series No. 116, p. 184, London 1918. "Dahlberg, A. O. and Garner, H. S., Bui. 944, Bu. An. Ind., U. S. Dept. Agr 1921. " Ayers, S. H. and Johnson, W. T. Jr. The Alcohol Test in Relation to Milk. U. S. Dept. Agri. Bui. 202, p. 35, 1915. 18 Evenson, O. L. A Color Test for "Remade Milk and Cream." Jor. Dairy Sci.. Vol. V, No. 1, 1922. 1* Robinson, R. H. The Determination of Formaldehyde in Solution. Chemist-Analyst. No. 29. Apr. 1919. -0 Wilcox, E. V. Production and Inspection of Milk. Hawaii. Agri. Exp. Sta. Bui. 1912. ^iHunziker, Otto P. The Butter Industry, 1920. 22 Methods of A. O. A. C. Bui. No. 107. (Revised) 1912. 2'' Chem. Zeit. 1899, 23, 312, Abs. Analyst, 24, p. 206. 2'' Patrick, G. E. Household Tests for the Detection of Oleomargarine and Renovated Butter, Farmer's Bulletin 131. 25 Jour. Ind. Eng. Chem. 12. 366-8, 1920. 28 Dingler's Polyt. Jour., 25, 1884, p. 281. Zeits. Unters. Nahr. Genussm., 4, 1901, p. 913. 27 Congdon, L. A. Jour. Ind. Eng. Chem. Vol. 7, No. 7. 1915. 28 Cook, A. A. and Woodman, A. G. Jour. Ind. Eng. Chem. Vol. 10, No. 7, 1918. 2»Bur. of Chem., Bull. 122, p. 52., 132, p. 122. 30 Am. Food Jour. Dec. 1916. P. 621. »i Clark, A. W. and DuBois, L. "Jelly Value" of gelatin and glue, Jour. Ind. Eng. Chem. Vol. 10, No. 9, 1918. »2 Jour. Ind. Eng. Chem. Vol. 8, No. 8, 1916. =» Hammer, B. W. and Johnson, A. R. The Specific Heat of Milk and Milk Derivatives. Agri. Exp. Sta., Iowa State College of Agriculture and Mechanic Arts, Research Bui. No. 14, 1913. ^* Richmond. Dairy Chemistry, 1914, London, Charles Grifl^n and Com- pany, Limited. •■'5 Barthel, translated by Goodwin. Milk and Dairy Products, 1910, Lon- don. MacMillan and Co., Limited. 38 Atkins. Chem. News. 1908, 97, 241. »7 Stocking. Manual of Milk Products. 1917, N. Y. McMillan Co. 38 Grimmer. Chemie and Physiologic der Milch, 1910. 3» Heineman. Milk, 1919, Philadelphia, W. B. Saunders Company. *« Chem. Bui. Vol 7, No. 4, 1920. " Van Slyke, L. L. and Baker, J. C. Studies Relating to Milk Tech. Bui. No. 65, N. Y. Agr. Exp. Sta. 1918. *2 Arrhenius, S. Ueber die Dissociation in Wasser geloesten Stoffe. Z. physik. Chem. 631, 1887. 4»Bigelow, W. D. and Cathcart, P. H.; Bui. 17-L, 1921. Nat. Canners Assn. " Baker, J. C. and Van Slyke, L. L. N. Y. Agri. Exp. Sta., Geneva, N. Y. Tech. Bui. No. 65, 1918. •■5 Clark, W. M. Jor. Biol. Chem. 23; 475, 1915. *« *7 Baker, J. C. and Van Slyke, L. L. J. Biol. Chem. 2, 337, 357, 1919. *8 McCrudden, F. H., U. S. Public Health Rpt. Vol. 37, No. 7, 1922. *» Clark, W. M. and Lubs, H. A., J. Bact. 2, 1, 109, 191. CHAPTER XVIII THE PURPOSE AND ADVANTAGE OF THE VACUUM PAN IN THE DAIRY INDUSTRY The use of the vacuum pan in the dairy industry dates back to the invention of Gail Borden to whom patent Avas granted in 1856. The historical side of the milk condensing industry is ably discussed by Prof. 0. F. Hunziker, in "Condensed Milk and Milk Powder," to which the reader is referred. The purpose of the vacuum pan in the dairy industry is primarily to remove water from dairy products, thus making it possible to manufacture a new class of products. The advantages derived by evaporating in vacuo as against evaporating in the open air are numerous, the principal of which are the following : (a). The Economic Advantage. To evaporate one pound of water from milk in the open air, starting with a temperature of 60° F. and calculating the specific heat of milk at 0.93 requires the expenditure of 1107 B. T. U. To remove the same amount of water under vacuo at 140° F. requires the expenditure of only 1040 B. T. U., or a saving of 6.4 per cent in heat units. (b). The rate of evaporation in vacuo is very much greater than in the open air, due to the fact that the boiling point de- creases with lowering pressures. This is illustrated best by reference to Table 120, which is based upon the table by Hunziker^ entitled: "Boiling points of water at different vacua." The last column in Table 120 is based upon a careful experiment the object of which was to determine the rate of evaporation under different vacua. Under good conditions of practical operation it is iisually possible to evaporate about 30 pounds per hour, per square foot of heating surface in the vacuum pan. Under the vacuum usually obtainable in practice, namely, about 26 inches of mercury as shown in Table 120 and upon the [684] Boiling Points 685 TABLE 120. Relation Boiling Points Vacuo and Rate of Evaporation. Absolute pressure per square inch Vacuum inches of mercury column Vacuum millimeters of mercury column Boiling points of water at degrees F. Boiling points of water at degrees C. Pounds of water evaporated per hour, per sq. ft. of heating surface. Approximate values 14.720 212.00 100.00 8.2 14.010 1.42 36 209.55 98.5 9.4 13.015 3.45 88 205.87 96.8 11.0 12.015 5.40 139 201.96 94.3 13.0 11.020 7.52 191 197.75 91.9 14.7 10.020 9.56 243 193.22 89.5 16.5 9.020 11.60 295 188.27 86.75 18.2 8.024 13.63 346 182.86 83.7 20.0 7.024 15.67 398 176.85 80.5 21.7 6.024 17.70 450 170.06 76.8 23.4 5.029 19.74 502 162.28 72.5 25.2 4.029 21.78 553 153.01 67.2 27.0 3.034 23.81 605 141.52 60.8 28.7 2.034 25.85 657 126.15 52.3 30.2 1.040 27.88 708 101.83 38.7 Not determined .980 28.00 712 100.00 37.8 •• .735 28.50 724 90.00 32.2 •• .544 28.89 734 80.00 26.7 •' .402 29.18 741 70.00 21.1 •' .294 29.40 747 60.00 15.6 " .216 29.56 751 50.00 10.0 " .162 29.67 754 40.00 4.4 " .127 29.74 756 32.00 686 The Vacuum Pan graph under Fig. 160, the quantity of water possible to evapo- rate per square foot of heating surface, decreases rapidly with a decrease in the vacuum. In other words, it would take nearly four times as long to evaporate the same amount of water at air pressures than under 25.85 inches of mercury vacuum. 5. WATER EVAR PER HOUf^ PER 3Q. FT TING 6URFACE Pig-. 160. Founds of Water Evaporated per Hour per Square Poot of Keating' Surface, Under Different Pressures in the Vacuum Fan. (c). The greatest advantage is probably the fact that under vacuum the various constituents of milk undergo no changes in flavor, color or chemical composition, owing to the low tem- peratures employed, and the short time necessary to hold the milk under heat during the condensing operation. It is these advantages that have made it possible to manufacture and market many new products of great commercial importance, that were unknown before the advent of the vacuum pan in the dairy in- dustry. DESCRIPTION OF THE VACUUM PAN. Many different types of vacuum pans are upon the market, and in use. The reader is referred to "Condensed Milk and Milk Powder" by Prof. 0. F. Hunziker,^ for a description of MojoNNiER Type Pan 687 these various types. For the purpose of enunciating principles the Mojonnier type of vacuum pan is the only one explained herewith, and illustrated under Fig. 161. HANDHOLE CONDENSER VACUUM LINE 8c CONDENSATION DRAWOFF PEEP HOL LIGHT DOME WAIST VACUUM GAUGE AIR BRAKE MANHOLE & PEEP HOLE MILK INLET COCK STEAM COI JACKET STRIKING CUP MILK DRAW-OFF COCK Pig. 161. Mojonnier Type Vacuum Pan. All vacuum pans consist essentially of five principal parts, together with the necessary control devices. The design of each 688 The Vacuum Pan of these parts has a large bearing upon the subsequent operation of the pan itself. These various parts are as follows : (a). The Condenser. It is here that the vapors which are evaporated from the milk are condensed to the liquid form. This should be so designed and proportioned as to remove the in- coming vapors in the least time and with the use of the least possible amount of water. (b). The Dome. This supports the condenser, and upon it are usually fastened the majority of the accessories such as the manhole, vacuum gauge thermometer, eye glasses, and buttercup valve. It should be sufficiently strong to support the condenser, and the atmospheric pressure. The opening into the condenser should be large enough to permit of the free and ready passage of the expanded vapors from the pan into the condenser. One pound of saturated steam at 126.27° F. under 25.88 inches of mercury vacuum will occupy 173.6 cubic feet as against 26.36 cubic feet for an equal weight of saturated steam at 212° F. The shape of the dome is also a factor in helping to prevent entrainment of milk solids into the condenser. The oval dome as shown upon the illustration under Fig. 161 is of the proper design to help prevent such losses. (c). The Waist. This part requires the use of heavy copper, in order that it may stand up properly under the work that is required of it. A frequent mistake is to make this part too low thus 'making a condition that favors entrainment losses. (d). The Jacket. This is supplied either with double copper jacket or with the outside jacket made of cast iron. The double copper jacket helps to prevent water leakage at the coil joints. This is the cause of considerable trouble in the case of pans fitted with cast iron jackets, owing to the unequal coefficient of expan- sion of the two metals, — that of copper being nearly 50 per cent larger than that of cast iron. A deeply dished jacket presents many advantages over the shallow type. It makes for greater strength, and it also makes it possible to set the coils low, and thus begin the evaporation in a minimum of time. This also helps to prevent entrainment losses. (e). The Coils. The proper size, quantity and design of the coils in a large measure determine the success of the pan. The Pan Sizes and Capacities 689 openings into the coils should be large enough to permit of the use of exhaust steam. Coils of the basket type help to keep the level of the milk low, thus preventing entrainment losses. The spiral shape of basket type coils also permits the water which is condensed from the steam to flow out rapidly to the outlet. COMMERCIAL SIZES, AND CAPACITIES OF VACUUM PANS IN TERMS OF BOTH RAW AND FINISHED PRODUCTS. Various sizes of vacuum pans are obtainable, the choice of size being governed by the quantity of product that it is desired to handle. Table 121 lists the most commonly used sizes. Like- wise it gives the approximate hourly rating of the various sizes in terms of both raw and finished products. The list is confined to the most common of the commercial condensed milk products. The ratings are very conservative, and under the most efficient operation these can be increased as much as 20 to 25 per cent. - One example will serve to illustrate the method of calculation used. Example : — What is the capacity of a vacuum pan, diameter 3 feet, making sweetened condensed whole milk? Whole milk tests 3.43 per cent fat, and 12.0 per cent total solids. Finished product tests 8.0 per cent fat, 20.0 per cent milk solids not fat, and 46.0 per cent sugar. Pan has capacity to remove 1000 lbs. water per hour. Solution : — 28.0 -~ .12 = 233.2. lbs. whole milk required for every 100 lbs. finished product. 233.2 -f- 46 = 279.2, lbs. total products required for every 100 lbs. finished product. 279.2 — 100 =■ 179.2, water removed for every 100 lbs. finished product. 1000 ^ 179.2 X 100 — 558, lbs. finished product per hour. 558 X .28 — =1302, lbs. whole milk per hour. Proof : — 558 X .466 = 256, lbs. sugar. 1302 + 256 — 1558, lbs. total raw products. 1558 — 558 = 1000, lbs. water removed per hour. 690 The Vacuum Pan cu m Finished product testing 10.0 per cent fat 14 . per cent sugar . 5 per cent gelatin 11.5 per cent milk solids not fat 36.0 per cent total solids Whole Milk testing 3.67 per cent fat and 12.00 per cent total solids o A Finished product testing 25.0 per cent total solids Buttermilk testing 8.80 per cent total solids Finished product testing 26.40 per cent total solids Skim-milk testing 8.80 per cent total solids Finished product testing 8.00 per cent fat and 26.15 per cent total solids. Whole milk testing 3.6 per cent fat and 12.00 per cent total solids Finished product testing 28.0 per cent milk solids and 74.0 per cent total solids Whole milk testing 3.43 per cent fat and 12 per cent total solids Finished product testing 28.0 per cent milk solids and 70.0 per cent total solids Skim-milk testing 8.8 per cent total solids Pounds water evaporated per hour Diameter of vacuum pan Vacuum Pump 691 THE VACUUM PUMP. Two different classes of vacuum pumps are available : name- ly, the dry vacuum and the wet vacuum. In the dry vacuum pump the condensed vapors do not discharge through the pump as in the case of wet vacuum pump. In the milk condensing in- dustry the wet vacuum pump is now almost universally used, probably the only exception being experimental plants that desire to study the condensation. Courtesy J. J. ReiUy Co. Pigr. 162. Straight Type Wet Vacuum Pumps In turn, there are several types of the wet vacuum pump, namely the straight type as illustrated under Fig. 162 ; the crank and fly wheel type, and types that are either belt driven or driven by direct attached motors. The choice of type is govern- ed entirely by local considerations, the principal of which is the unit power cost. The crank and fly wheel type is the most effi- cient from the standpoint of steam consumption, but its first cost is the largest of any of the common types, and it is bulky and occupies much floor space. "When the exhaust steam is used in the pan, in the end the straight line pump is equally economical, and that is the type that is by far the most commonly used. 692 The Vacuum Pan The correct sizes of vacuum pumps to use upon various sizes of pans, is indicated in Table 122. This comprises only pumps of the straight line type. In the case of 3 feet diameter and 7 feet diameter pans a choice of sizes is given. At low altitudes the smaller sizes will render good service, while at higher altitudes, the larger sizes will usually prove to be the more satisfactory. TABLE 122. Sizes of Vacuum Pumps Recommended for Various Sizes of Vacuum Pans. Size of vacuum pan SIZE OF VACUUM PUMP Size of vacuum pan SIZE OF VACUUM PUMP Diameter of steam cylinder Diameter of water cylinder Length of stroke Diameter of steam cylinder Diameter of water cylinder Length stroke 3'0" 7" 10" 10" 5'0" . 10" 16" 20" 3'0" 8" 10" 12" 6'0"6'6" and 7' 0" 12" 18" 20" S'O' 8" 12" 12" 7'0" 14" 20" 20" 4' 2" 10" 14" 16" STEAM PIPING UPON VACUUM PAN TO USE EITHER LIVE OR EXHAUST STEAM. Numerous methods are employed to introduce steam into the coils and jackets of vacuum pans, and likewise to remove the condensation from the same. Wherever any exhaust steam is available this should be used, and the deficiency made up with live steam. In Fig. 163 a complete scheme of piping is shown whereby either live or exhaust steam can be used to operate the vacuum pan. The scheme is the simplest and at the same time the most satisfactory one possible. Exhaust steam can be utilized to the extent of the quantity available. If more exhaust steam is avail- able than the pan can utilize, the relief valve will operate and permit the escape of the surplus exhaust steam either into the open air, or into the feed water heater. If no exhaust steam is available, the lower end of the low pressure header can be closed with a blank flange. If exhaust steam is used, the coil openings Vacuum Pan with Piping 693 iTEAM PRESSURE. RE.GULATOR-. LIVL STEAM LINi- LIVE: 6TLAM 5DPFLV VALVL^ OUTtR COI L CONTROL VALVL- SAFE-TYPOPVALVt- i nnlr coi l cont rol valve.- lowe:r coil control valvl- EJ(HAU5T3TtAMLINt-- STEAM SLPA1?AT0R- Tig. 163. Fipingr Scheme Sug-gested for Connectingf a Vacuum Fan to Operate Upon Either or Both Iiive and Exhaust Steam. 694 The Vacuum Pan should be large enough to admit the increased volume due to the low pressure of the steam. Equal weights of saturated steam will occupy about five times more space at 5 pounds than at 100 pounds pressure. At the discharge from the pan single traps are provided for each coil and the jacket. Good makes of either thermostatic or gravity traps will operate with equal satisfaction. The condensation from the trap, in turn, discharges into a re- ceiver which is connected to a boiler feed pump, which pumps the condensation directly into the boilers as fast as it accumu- lates. The suggested scheme of piping makes it possible to condense the milk with the smallest number of heat units, and with the expenditure of the smallest amount of labor. Suggested Location of Contro] Devices. The location of all the control devices is also indicated in Fig. 163. The proper selection and location of these several devices will do much to promote the efficient operation of the pan. Local conditions frequently make it necessary to modify the locations shown. RELATION OF WATER REQUIRED IN THE CONDENSER, TO THE WATER REMOVED FROM THE MILK IN THE VACUUM PAN. The quantity of water required to condense the steam vapors arising from the milk in the vacuum pan, varies under several different conditions. Table 123 gives the number of pounds of water required in the condenser for every pound of water evaporated in the vacuum pan under many different conditions of operation. The values given are the theoretical values. In practice the total requirements under the same conditions as named under Table 123 are about five per cent higher than the values given. This statement is based upon the results of carefully conducted experiments made to determine this point. The method of calculation used is illustrated by the follow- ing example : — Example : — ^How many pounds of water, temperature 55° F., will be required to condense one pound steam in vacuum pan. Water vapors 140° F. Condensation 130° F.? Water Rijouirements 695 a, > > o a> 00 ^ ^ 3 -« w ^ U £ % 5 09 t-i v s H a 1- k CO d lO O CO o d o5 c 1 1— 1 CO C35 05 T— 1 d CO CO o CO I— ( d O O "0 CO CO o o 8 a l! il . 2"S D. fe-S ca o 1 00 d 05 CO CO CO d CM CO 00 00 2 CO ^' d 05 CO CO d CO 00 05 1 CO d 05 d 05 CO CO 00 CO C3> 05 1 as II •safe fe-a o iC o CO o uO 1^ C5 o d CO d CO o CO d 05 00 CO ° 00 00 (M o CO CO CD I— 1 OS c II I*- t_ III II D •a 05 CO CO d d CM CO 00 00 CO 05 1 CO iC 00 00 04 00 cs 05 CO •* s CM 2 Tt* d d (M C3 CO CO CO c c >Z >. « "S il il . |«i II o O CO o no t^ t^ 02 o CO CI 1 o CD CO C5 CO o O 00 05 o o 05 00 CO CD C<1 05 1 -2.s| ea C te . oWt3 k lit o CC o k If: 1 696 The Vacuum Pan Solution : — (a). 140 — 130=: 10, B.T.U. required to cool vapors to tem- perature of condensation. 966 B.T.U. required to evaporate one pound of water in the pan. 966 -|- 10 = 976, B.T.U. required for evaporation of one pound of water. (b). 130 — 55 =r 75, B.T.U. available per pound water sup- plied in the condenser. 976 = 13.0, pounds water required per pound steam evapo- 75 rated m the pan. The percentage increase in the volume of water required un- der various conditions of operation, as compared with water at a temperature of 35° F. is given in Table 124. This table is based upon the values given in Table 123. One example will serve to illustrate the derivation of the table. Example :^ — With the water vapors in the pan at 140" F., and the condenser water at 130° F., 10,3 pounds of water at 35° F. are required for each pound of water vapor removed. Using water at 55° F., 13.0 pounds are required, per pound of water. What percentage increase in volume of water is required at 55° F.? Solution : — 13.0 — 10.3 = 2.7, pounds increase. 2.7 divided by .103 = 26.21, per cent increase. The following conclusions are based upon the values given in Tables 123 and 124. (a). The warmer the water entering the condenser, the larg- er the volume required. The most efficient use is made of the "^ndenser Avater, when the temperature of the water vapors in +*>o, pan is maintained at about 140° F. (b). The greater the difference between the temperature of fhe water vapors in the pan, and the outgoing water temperatures in the condenser, the greater will be the volume of water re- quired. Water Requirements 697 u >. a o M 03 ■M CQ P o 0) "O ^ c ea ce H P^ ■g >n ^ o CO o IH a t-i «i H ,£3 « < ^ H ^ a "O o 9 u rr e V K (1) 09 cS i3 ^ Ml o s 1 l5 o >> c o ?5 o ■o o 00 00 CO d 00 d 00 7 [^ B fe P s^^ cs ■* t^ tt »- & II > -. 1 ^ i. C3 Q -S >, c52 lO ^H Cft ■^ CO 00 ^ o Sa^ Ol CO t^ (M CO CO K? ■S s O o ■ ^ 3 £ ^ c l.Oi o -^ 00 d 03 d ^ P (£'"' CO •o 00 Tt* ?5 CO s ^ >i eS o (M lO CO C<1 »o C °, I^ 05 lO 05 03 00 a< C^ 'c I.o ^ ^ c ti (^^ (M "0 00 CO ° J? ™ a Is J S " > ♦i J H I. « Q -S >> ■£=2 fO CO rH 00 T-H CO 5 rt o go CO 00 -* GO CD rt ^ c o ■ pS 1^ ^" c ^'^ CO ^ ^ t^ o r-H p iS"^ CO CO ° CO g g B ^ >1 cS! CO _^ o CO Oi c o ■tJ g o •^ 05 t^ s o Ph *" ^^ (N c ^CO d CO 00 (M Oi cD c g'fe p f£^ CO lO 00 l-H CO § i o. = o J a >i c2S IS 00 t^ t^ CO rti fc. o ■4^ §o CO (M t^ o CO O B O o • ^ ^£ ^ 'S ^o CO t^ lO d ,^ l^ D oi'^ CO CO o o f^ T-H IM ■* TJH '"' * . """"^ e a o o ^ >> ■eco £o5 CO 00 s § 8 8 -,»' tz o ^ o ■ CL, *" ^^ c T^^-o CO d t*l r>- g ^ o . a fe P Ph ""^ CO lO o 05 ^ •~ fa 'S . I-^ CO t>. *3 D. Is > - J a J H t. c« Q -s >-> "e '"^ iM 00 CO ■* CO ^ rt o g CO t^ ^H CO CO t^ CQ OJ c ^ o • 1 1- O c te^ O) lO CO 05 (M p eS'^ CO t^ CO T-H ^ 00 lO a ^ >> bOO (M (M (M Q »o (M B o cS^ 05 O) CO o 00 liO eu **^ ^ 'c tjiO CD CO ■^ ^ CO ,_, B . a fe. '"' p CL, *"* CO CO <3 M o 'Z ^ 'S *-H c^ CO Tt- ™ a as > ^ J a .2 H I. « Q -s >. cO 00 l>. rH CO t-^ -2 ^ " o .■^t- o 00 (N c^ CO s o ■ ^ ■^ c fc"^ 3! Tt< 00 c^ r^ p 0.^ -* 00 lO ?? 03 —' 1 3 e>o ■S a 1. 2 i H o_ o Q o Q Q o o !5 O iC lO lO lO iO iO 1 cc ■* lO CO r^ 00 05 o 1 1 1 1 1 1 1 1 698 The Vacuum Pan The increase in the volume of water required due to the de- crease in the temperature of the water vapors in the pan is in- dicated in Table 124. This table is based in large part upon the results given in Table 123. One example will suffice to illustrate the method of calculation used. Example : — With the water vapors in the pan at 140° F. ; the incoming condenser water 35° F. ; and the outgoing condenser water 130° F., 10.3 pounds of water are required for each pound of water vapor removed. How much more water will be required if the temperature of the water vapors is 135° F. and the outgoing condenser water 125° F.? Solution : 10.8 — 10.3 =: .5, pounds more water required. .50 -~ 10.3 =: 4.85, per cent more water required. Table 125 shows that the higher the temperature of the water vapors in the pan (not exceeding 140" F.) the 'less the quantity of water required in the condenser. This rule applies regardless of the temperature of the incoming water. TABLE 125. Percentage Increase in Volume in Excess of Water Required When the Pan Temperature is 140° F. In All Cases the Difference Between the Incoming and the Outgoing Condenser Water Temperatuie is 10° F. Temperature Temperature (F) Steam Vapors in Pan (F) water entering 135° 130° 125° 120° condenser Per cent Por cent Per cent Per cent 35° 4.85 11.65 18.44 26.21 45° 6.09 13.04 20.87 30.43 55° 6.92 15.38 25.38 36.15 65° 8.67 18.00 30.00 44.66 75° 10.17 22.60 37.85 57.63 85° 12.44 28.57 49.77 79.72 95° 17.20 39.78 74.91 133.33 105° 25.13 66.92 152.82 400.51 STEAM REQUIRED TO CONDENSE MILK IN THE VACUUM PAN. The total heat units required to condense milk is the sum of the heat units required to forewarm the milk in the hot wells, Hot Wklls 699 plus the heat units required to evaporate the water in the vac- uum pan. This will vary under several different conditions, the principal factors causing variations being, (a) the type of hot wells, or method of preheating used; (b) the type, efficiency, and general operating condition of the pan used; (c) the temperature and the composition of the product that is to be condensed; (d) the temperature of the steam used both at the hot wells and in the vacuum pan. Type of hot well. As described in Chapter XIX, the two types of hot wells in general use are the plain and the jacketed. In the plain type the heating of the milk is accom- plished by introducing live steam directly into the milk. In the jacketed type the heat is transmitted to the milk through the jacket, in which case no steam needs to be condensed directly into the milk. It is sometimes the practice however, to heat the milk through the jacket up to about 180° F., and then to com- plete the heating up to 210° F. by means of both the jacket and live steam introduced directly into the milk. Table 126 shows the amount of steam condensed into milk at various initial temperatures, heated to both 140° F. and 210° F., and using steam of various pressures, in plain type hot M^ells. The percentages indicated in the table prove plainly that this is a considerable factor in the efficient operation of a vacuum pan. The figures given apply only to whole milk of the test indicated. The values will vary with the specific heat of the product that is being heated in the hot well. In the case of the fresh milk covered by the table, the specific heat was calculated at 0.935. Table 127 gives the pounds of steam required both to fore- warm and condense the raw materials necessary to make one pound of various condensed milk products. The values are given covering various conditions of operation, particularly with re- gards to method of forewarming employed. The table also gives the pounds of steam required, per pound of water evaporated out of the fluid milk, together with the percentage increase in the use of steam when using plain type, instead of jacketed type of hot wells. 700 The Vacuum Pan «J ,2 a "^ O 'm u ^ © v eo '-n u be « -4-" a) k> ■i< " «*-c ^ o ° S O +j 2 -a e •c c o ^ rt o C4 c O i^ t-H 3 w Oi e »-] -<-> PQ H 0) o o ri C W HH »-H 13 X be W Sfi O! O) e ^ Ph S S « S "•g 5 c S "o 03 Ph " 03 oj S 02 o c ° £ • s Oh = *- & c '=' e a g o S s ^ ^ A *> C . -^ o o c C t3 •-■ > Ph CO ^ Pi o ^ fit C8 Cii 9) P< a> -O OQ 0> a M o -o a 00 <« s trt RJ ^ -M E rt Oi o I^ O Oi CO CO O) ■^ -# O d 1*0 S •— 1—1 IN fS" ^ n'-'C'*" til ^ O) 1^ CO .—1 ■* CO IC P-i a r- .i|o= c» 05 IN s £ T-^ r^ .—1 o Cft O r; O O pI*^ ^ ^ ^ :s. ►^ rr, (^^^ ,-; ■ rt rt rt _; ^ CL,«W<5 £ S T3- o oP oj o »— < •* IM o 00 CO o 3 T3 o J3 o m cc o CO 05 IN (N 00 00 fe O '^K -d 6 S = ■s o t^ O 00 o r^ ^ Ttl >o C5 IN 00 'H o Tf CO CO CO O 110 S eq 2 Cj CI^E-M -1 oi (N CO IN (3 ^ O K to o r^ o 00 o 3 O o t^ -f 00 00 UO 03 o >o CO lO CO fL| M ^ (N ^ O-— 03 O (P Og-=M a B CO tl C^l M o 03 (N ■* o O ir> (D o 00 t^ •^ cc g|-S- -i (N - M '-i 3 og a fe3^^ £ '^ " -s >o -t< lO o CO rt< CO '*> o> ■* CO CO Ol Tf lO IN ^ , — 1 °-B £ — d 3 -t< CO lO o 00 ,^ CO c^ o CO IN 0 5f ' ■3 0.^03 s CO r: 00 flj . |(N OOO 03 03 a 00 in 03 Calculation of Water, Steam, Fuel 703 RELATION OF GAS, OIL AND COAL CONSUMPTION TO STEAM PRODUCTION. It is frequently desirable to know the relation between the fuel supply, and the steam produced in the boiler. Obviously this is open to wide fluctuations, the principal factors causing varia- tions being the kind of fuel; type of boiler used; quality of the water supply, and especially the efficiency of the methods of firing- employed. Due to these variables there is a wide gap in practice between the theoretical and the actual steam production. Table 128 shows the above relations in the case of several of the most common American fuels, giving the steam produced at pressures of 5, 10 and 100 lbs. each respectively. Obviously the practical values given are only approximate, but yet they are accurate enough to serve as a practical guide. TO CALCULATE THE WATER, STEAM AND FUEL REQUIRED TO OPERATE A VACUUM PAN. It is frequently necessary to know, both for purposes of figuring costs, and for properly coordinating equipment capaci- ties, the water, steam and fuel necessary to condense milk into various products. The information given in this chapter is suf- ficient to permit anyone to arrive at these values quickly and easily. The following example will illustrate the principle of the cal- culation, and the same can be applied to any dairy product. Example : — "Wanted to condense 10000 lbs. skim-milk testing 8.80 per cent total solids, into sweetened condensed skim-milk testing 28.00 per cent milk solids and 42.00 per cent sugar. Pan vapors 140^ F. Condenser water 120° F. Plain hot wells used. Water at 55° F. costing 6 cents per 1000 gallons. One U. S. gallon of water weighs 8.345 pounds. Hocking Valley bituminous coal used costing $6.50 per ton. Find quantity of water and coal required. Solution : — (a). 10000 X 8.80 — 880, pounds total solids in skim-milk. 880 -f- .28 = 3143, pounds finished product possible to make. 704 The Vacuum Pan TABLE 128. Relation of Fuel Consumption to Steam Production. KIND OF FUEL Unit B. T. U. Pounds of steam produced by one unit of fuel starting with water at 32" F. and ending with steam at pressure indicated. Theo- retical Practical 100 lbs. 100 lbs. 10 lbs. 5 lbs. Natural gas, Ohio Cu. ft. 1020' .86 .65 .67 67 Natural gas, Pa Cu. ft. 1073' .91 .68 .70 67 Producer gas Cu. ft. 145^ .12 .09 .09 .09 Coal gas Cu. ft. 599' .51 .38 .39 39 Crude Oil, Calif Pound Sp.Gr. 0.966 18667' 15,75 11.81 12.11 12.15 Crude Oil, Texas Pound Sp.Gr. 0.924 19060' 16.09 12.06 12.37 12.41 Crude Oil, residium Pound Sp.Gr. 0.860 19200' 16.20 12.15 12.47 12.50 Anthracite, Northern field.. Pound 13160' 11.11 7.78 7.96 8.01 Semi-anthracite, Loyalsack. . Pound 13920' 11.75 8.23 8.44 8.57 Semi-bituminous, Pocahontas, W. Va Pound 15070' 12.70 8.89 9.12 9.15 Bituminous, Pittsburgh, Pa. Pound 13410' 11.31 6.79 6.97 6.99 Bituminous, Hocking Valley, Ohio... Pound 12130' 10.24 6.14 6.30 6.32 Lignites, Utah Pound 11030' 9.31 5.12 5.25 5.27 Operation 705 3143 X -42 = 1320, pounds sugar required. 10000 — (3143 — 1320) = 8177, pounds water removed from skim-milk. (b). 8177 X (15.2 -^ 8.345) = 14896, gallons water required. 14.896 X .06 = $.89, cost of water, (e). 3143 X 3.398 = 10679, pounds of 5 lb. pressure steam re- quired. 10679 ~ 6.32 = 1690, pounds, or .845 ton of Hocking Valley coal required. (d). .845 X $6.50 = $5.49, cost of coal. THE OPERATION OF THE VACUUM PAN. The operation of the vacuum pan and its practical application in the manufacture of various condensed milk products is con- sidered here. The discussion includes methods recommended in forewarming as well as other steps comprised in the complete con- densing operation. 1. TO FOREWARM AND CONDENSE WHOLE MILK AND SKIM- MILK, BOTH PLAIN AND SUPERHEATED. (a). Forewarming or Heating in the Hot Wells. The forewarming operation is of very great importance as affecting the finished product. The influence of this operation is frequently neither properly understood nor properly appre- ciated in practice. In the manufacture of sterilized evaporated milk the fore- warming operation requires constant daily watching. The physical properties of the finished product are influenced very largely by the heat treatment given to the whole milk in the hot wells. At certain seasons too high a temperature in the hot wells raises the coagulating point of the finished product in the sterilizers, and thus makes it difficult, if not impossible, to pro- duce a product of the proper viscosity. Upon the other hand, in- sufficient forewarming lowers the coagulating point to such an extent as to make it difficult, if not impossible, to properly ster- ilize the finished product, on account of the excessive viscosity produced. The application of the above principles in practice, gives the processor one means for keeping the finished product under control. 706 The Vacuum Pan The above principles are also applied in the manufacture of superheated products, where the aim is to obtain all the viscosity possible up to the point where the product still remains smooth, and free from lumps. The range of forewarming temperatures in the case of ster- ilized evaporated milk, either whole or skim, is from 140° F. to 210° F. When as low a temperature as 140° F. is used, care must be taken to provide a safe sterilizing record. Under some conditions heating to 210° F., shutting off the steam, and heating again to 210° F. after a lapse of two to five minutes, may prove beneficial, but when this practice is followed, there is danger of producing a product too high in color. This latter trouble can be prevented to a considerable extent by reducing the sterilizing time and temperature to a minimum. The range of forewarming temperatures in the case of super- heated products is from 140° F. to 160° F. Obviously in these products the aim is to control the operations in such a way as to produce a high final viscosity. When using the plain type of hot well, the steam should be introduced into the milk at a pressure not to exceed ten pounds. Higher steam pressures are liable to cause chemical changes in the finished product. The steam line leading into the hot well should be fitted with an oil separator to remove any oil or water tliat might be contained in the steam. The forewarming should be so timed that the pan will be ready to receive the milk as soon as it has reached the desired temperature, in the hot wells. (b). To Start and Operate the Vacuum Pan. Before starting the operator should see that the pan is clean and thoroughly steamed ; that the water spray in the condenser is free from obstructions and that the stop valves upon the coils and jackets do not leak steam. The air vents are now all closed, and the vacuum pump is started up slowly, 'increasing the speed to 25 or 30 single strokes per minute. Open the water valve to the condenser as soon as 15" to 20" of vacuum are obtained, and the milk in the hot wells has reached the desired temperature. The milk inlet valve is now opened wide. The milk always rises due to the air in the Operation 707 same when first introduced into the pan. The operator must be upon the alert at this point and by means of the vacuum break introduce just enough air into the pan to hold the milk down to a safe limit. It will take only a few seconds for the pump to expel the air, and to obtain the proper vacuum. This result can be accomplished by the time the lower coils are covered with milk. In addition to introducing air in the pan to reduce the milk level, it may sometimes be necessar}^ to close off the milk suppl}^, and to shut off the steam for a few moments, until the proper vacuum has been reached. Sufficient milk should be in the pan, to cover one set of coils before turning on the steam. To arrive at the proper amount to introduce into the pan, it is suggested to fill one of the hot wells with water, to the level at which it is usually filled with milk. The water is now drawn into the pan until the lowest set of coils are all covered, and the new level upon the hot well is suit- ably marked for subsequent guidance. The above procedure will insure knowing just when the right amount of milk is in the pan to permit turning on the steam without danger of baking milk upon the coils. There is no other satisfactory way of doing this, owing to the foamy condition of the milk, in the pan. When turning on the steam, open the jacket valve first ; then the lowest coil, and the remaining coils after a lapse of three or four minutes. Whenever possible the condensing should be done with ex- haust steam. If insufficient exhaust steam is available to do all the condensing, the amount available should be utilized, and the shortage made up with live steam. Every well installed pan should be fitted to use either exhaust steam, live steam, or a com- bination of the two, when both are available. Simple devices are available for controlling automatically the pressure upon the steam header. The efficiency of exhaust steam for condensing purposes is due to its latent heat, thereby giving it a large number of available heat units, with a relatively low temperature. The higher the steam pressure the higher the temperature of the steam, without an increase in heat units proportional to the increase in tem- perature. These facts are of great moment in condensing milk. The higher the steam temperature, the greater the danger of the 708 The Vacuum Pan milk baking upon the coils, and also the greater the danger of the product being dark in color. It is not good practice to crowd the capacity of the pan by increasing the steam pressure inside the coils and jacket. The correct practice is to operate at moder- ate pressures, and within the ratings of the pan. Table 129 gives the available heat units and the temperature of exhaust steam, and of steam at various pressures. TABLE 129. Available Heat Units, Volume and Temperature of Steam at Various Pressures.- Pressure in pounds per square inch above sea level Temperature of steam Degrees F. Volume in cu. ft. occupied by one pound Normal heat expressed as B. T. U. in liquid form 32» F. Latent heat expressed as B. T. U. Total heat expressed as B. T. U. fromwaterat32''F. 212.00 26.36 180.9 965.7 1146.6 .3 213.03 26.14 181.8 965.1 1146.9 2.0 219.00 23.65 187.8 960.9 1148.7 3.5 223.47 21.78 191.9 957.8 1149.7 5. 227.05 19.54 196.0 954.0 1150.0 10. 239.32 15.90 208.4 945.5 1153.9 25. 266.65 10.29 235.9 926.3 1162.2 40. 286.53 7.66 255.9 912.8 1168.7 100. 337.66 3.76 398.5 876.1 1184.6 It is evident from the data contained in the above table that with a pan of proper design. — that is, one that contains the necessary heating surface, and amply large openings into the coils and jacket, every advantage is gained by using low pressure steam. Five pounds should be the maximum under proper oper- ating conditions. The same pressure should be carried upon the coils and the jacket. The steam in the jacket causes the milk to "kick up". That in the coils causes it to "roll", and to drop back towards the center of the pan. Operation 709 The level of the boiling milk should be not more than half way up the waist. The milk intake cock should be so adjusted that the milk will condense about as fast as it is drawn into the pan. The milk should test near the end of the run, and before lowering the steam pressure, from 5 to 10 points lower upon the hydrometer than the striking point desired. Also all the milk from the hot wells should be in the pan before turning off the steam. This will help to obtain a more correct hydrometer reading. The best pan temperature to maintain upon plain condensed milk is from 122° to 140° F. The best method is to maintain the temperature near 140° F., throughout the run until the finishing point is nearl.y reached. At this point the temperature can be dropped to about 120° F. by reducing the steam pressure. This will make for greater accuracy in arriving at the end point. Be- low 122° F. the evaporation becomes too slow, while above 140° F. the evaporation also becomes slower, and the higher temperature tends to produce a dark colored product. While the evaporation is proceeding rapidly, the temperature of the water vapors in the pan will be the same as that of the milk itself. Near the end of the run there may be a considerable difference between the two, so that the temperature of the milk itself should be the proper guide for the operator, especially when striking the batch. If the pan temperature should drop under the point at which it is desired to be carried, in order to raise it, the water supply should be decreased, and sometimes the steam supply can be increased to advantage. A drop in pan temperature as above may be due to a decrease in the steam supply, to water being carried over from the boilers, or to the condensation being im- properly removed from the coils and jacket. If the pan temperature should rise above 140° F., the water supply should be increased, and the steam pressure decreased. A condition of this kind may be caused by air leaks into the pan, increase in the steam pressure, without any corresponding in- crease in the water supply to the pan, or to the spray pipe in the condenser becoming clogged. /'lO The Vacuum Pan (c). To Strike the Batch. The reader is referred to Chapter XI for detailed information as to the specific gravity of evaporated milk under different con- ditions, and as to suggestions for striking the batch. This is an operation that requires both skill and care. The steam should be kept upon the coils and jacket as long as possible, in order not to reduce the capacity of the pan. And upon the other hand, it should not be kept on long enough to over-condense the milk. Usually the time method can be used to good advantage to aid in arriving at the striking point. Under this method the operator ascertains by experiment just how long it takes to in- crease the hydrometer reading one-tenth degree after the milk from the batch is all in the pan, and while the full steam pressure remains upon the coils and the jacket at a certain pan tem- perature. Example : — Test desired 6.35 degrees Baume at 140 ' P. Test increases at rate of .lO"" B. for every minute. Preliminary test found to be 6.05° Baume at l^O'' F. Solution : 6.35 — 6.05 =: .30, degrees short. .30 -f- .10 = 3, minutes additional necessary to operate pan be- fore turning off the steam. (d). To Finish the Pan Batch. The first step after reaching the striking point is to close off the steam valves. If plenty of cold water is available, leave the water valve to the condenser open, with the vacuum on, for two or three minutes. This will cool the milk in the pan to about 100° F., and thus it will assist greatly with the subsequent cooling of the batch. The vacuum break is now opened ; the water valve to the condenser is closed, and the vacuum pump is shut down. Do not open the draw off valve until the vacuum has been reduced to two or three inches. If opened sooner, the manhole cover may be blown off, or some milk may be lost. The proper handling of the milk immediately after it leaves the pan, is of prime importance. Equipment should be on hand to cool the product from the pan rapidly and efficiently^ (e). To Superheat the Batch. Superheating both condensed, whole and skim-railk is an old established trade custom. Possibly with but few exceptional Finishing the Batch 711 cases there is but little merit or advantage to this practice, in so far as it may improve the quality of the product. The super- heating coagulates part of both the albumin and the casein, thus greatly increasing the viscosity without increasing the total solids in the product. It frequently happens that superheating may give an entirely false impression as to the total solids content of the product. The modern tendency is to buy milk products upon the basis of their fat and total solids contents, together with the necessary specifications regarding their essential physical pro- perties. The method of superheating given herewith is inserted for the benefit of those called upon to furnish such products. As already noted, when making superheated products, the fluid milk in the hot wells, should not be heated to exceed 160° F. Condense the milk in the pan as described above. Strike the batch about two degrees Baume higher then necessary to pro- duce the total solids desired. The steam condensed into the milk in superheating should not dilute the milk under the standard desired. Keep the temperature up to 140° F. at the time of striking. The steam from the coils and the jacket is now turned off, and the vacuum pump is shut down, but the vacuum is allow- ed to remain in the pan. The superheating steam valve is now opened wide, using full boiler pressure up to 100 pounds. Lower pressures will unduly prolong this operation. Obviously as the temperature of the milk rises, the 'vacuum in the pan decreases. The superheating is continued until the milk reaches a temper- ature of 180° F., and the vacuum has reached about 13". The end temperature has to be varied depending upon the concentra- tion, and the condition of the milk. Obviously milk of higher concentration will reach the desired viscosity in superheating at a lower temperature than milk of lower concentration. Like- wise milk of high acid content will superheat much more rapidly, and at lower temperatures, than milk of low acid content, or than milk with low coagulating point due to causes other than the acidity of the same. Likewise milk with high coagulating point, has to be superheated at times, as high as 190° F., before obtaining the desired viscosity. The end point in superheating is found by sampling at the striking cup. If the superheating is carried too far there is danger of "cracking" the product. That is, of coagulating the 712 The Vacuum Pan casein in lumps, so that the product loses its smooth, velvety ap- pearance. This can be avoided by care and experience, and if by chance the superheating has been carried too far, the lumpy condition thus produced can be overcome by running- the product through the homogenizer. But of course the preventative is bet- ter than the cure. The superheating operation consumes con- siderable time, requiring about 30 minutes for about 5000 pounds of finished product, upon the proper size of pan. When the desired viscosity has been obtained, the super- heating valve is closed ; the vacuum pump is started ; and the water is turned on in the condenser, very slowly at first. The batch is now cooled in the pan to at least 140° F., — preferably to 120° F. before dropping it out of the pan. On account of its viscous condition, superheated condensed milk is one of the most difficult of all dairy products to cool. The proper cooling of this product requires the use of equipment well designed for this work, and the use of cooling mediums of low temperature. The product should be tested for fat and total solids while the batch is being cooled, and the materials necessary to use for standardizing should subsequently be added, cooled and mixed with the balance of the batch. (f). Precautions in Pan Operation. The efficient operation of a vacuum pan is influenced by sev- eral conditions that should be well understood by every pan op- erator. The following are the most important of these conditions : Condition of Heating- Surfaces. Two conditions may exist to decrease the efficiency of the heating surfaces. The outside of the coils and the jacket may become coated Math coagulated milk. This condition is caused by the use of too high steam pressure ; by the presence of water inside of the coils ; by condensing milk too high in acidity ; Jjy turning on steam before the heating surfaces are all covered ; by condensing too many batches before cleaning the pan, and by careless, im- proper cleaning of the pan. The layer of milk acts as an insu- lator, and greatly hinders the transmission of the heat from the steam to the milk. Under good operation the above difficulties can be readily eliminated. Air Leaks 713 The inside of the coils and the jacket may become partly or completely filled with water, due to improper methods of trap- ping off the condensation; improper coil or jacket construction, or the use of steam containing much water condensed into it. The coils should be designed to completely and rapidly carry off the Avater as soon as it forms. The water also acts as an insu- lator, and prevents the transmission of the heat from the steam to the milk. The tAvo conditions described above are graphically illustrated under Fig. 164. These conditions greatly reduce the capacity of vacuum pans, and to a lesser extent cause the use of increased amounts of both steam and water. WALL OF COPPLR TUBE CONDLNSLD STLAM WALL OF COPPLR TUBL CRUST OF MILK SOLIDS Fig-. 164. Factors That Influence Heat Transmission. Air Leaks Into Pan. If any considerable amount of air should get into the pan, while under operation, the milk intake valve should be immediately shut off. As soon as the air enters the pan, the milk Avill cease boiling, and it will appear motionless upon the bottom of the pan. Just as soon as the vacuum pump begins again to remove the air and to form vacuum, the milk will immediately get very wild and foamy. Great care must be 714 The Vacuum Pan exercised by the operator at this moment. Just enough air should be introduced through the vacuum break to keep down the milk in the pan until the proper vacuum has been regained. The steam can be then gradually turned on the coils and jacket. The steam should be shut ofif from the coils and the jacket just as soon as the above condition is discovered. If this is not done, the heating surfaces will soon become coated with milk. Large air leaks into the pan are caused principally by the water supply tank becoming dry ; to the accidental breaking of an eye glass ; to the emptying of a hot well without closing the milk intake valve; or when jacketed hot wells are used, to air being drawn in through the "whirlpool". This last named con- dition can be simply and easily prevented by a small device used for that purpose. Pig-. 165. Device for Breaking 'Whirlpool in Jacketed Hot Well. To Be Inserted in Discharge Opening. Influence of Bicarbonate of soda. If bicarbonate of soda is added to the last portions of milk remaining in the hot wells, and just before drawing into the pan, this will cause the milk in the pan to become very wild and foamy, due to the excessive amount of carbon dioxide generated. Under these conditions great care must be exercised by the op- erator, and the milk should be drawn into the pan only as fast as the vacuum pump can expel the gas. "When necessary to use bicarbonate of soda, this should be added to the milk in the hot wells before any steam has been introduced into the milk. Under these conditions a large part of the gas will be eliminated as the milk is being heated, and before it enters the pan. Cleaning the Pan. After the day's run has been completed draw enough water into the pan to submerge all the coils. Allow to stand for at least 15 minutes, or if time is available, as much as several hours. Empty and clean the pan, taking care that the milk is completely removed. Losses 715 The cleaning of vacuum pans and hot wells can be greatly facilitated by the use of caustic alkali, properly applied. The use of caustic alkali for this purpose originated in Europe, and full report upon the subject was made by Dr. Hamilton." In order to obtain proper results it is necessary to use the right concentration of the alkali, and to apply it hot. Devices are available for accomplishing this result simply and efficiently. The merit of this method is owing to the solubility of coagu- lated casein and albumin in even very dilute solutions of caustic alkali. Soon after applying the alkali, it becomes possible to re- move the coagulated products, which under the action of the alkali, have been converted into slimy substances, that are easily removed from the heating surfaces. In using caustic alkali good judgment must be exercised. It should be applied only a few minutes before the cleaning of the pan is started, and it should be applied only to the surfaces con- taining coagulated milk. Under no condition should the alkali be added for any considerable time before cleaning the pan. These precautions are necessary owing to the solubility of tin in caustic alkali, causing decomposition of the solder, and thus weakening the seams of the pan. The final step in cleaning a pan is to rinse the pan freely with w^ater, and then in turn to follow up the rinsing with a thorough steaming. The pan will thus soon become thoroughly dry, with- out any verdigris forming in it. The rinsing and steaming should be repeated before starting the pan, the following morn- ing. Entrainment Losses. By this is meant the solid portions that are mechanically carried over into the condenser. These losses are caused by improper pan design ; by carrying the milk too high in the waist of the pan; by careless operation, or by large air leaks. The same may be reduced to small proportions by careful operation. A good index of entrainment losses is the color of the water discharging from the vacuum pump. Even slight coloration is an indication of milk solids being carried over into the condenser. There is also a small loss due to stickage, which is caused by conditions already named, all of which can be very largely pre- vented, under careful operation. 716 The Vacuum Pan (2). TO FOREWARM AND CONDENSE BOTH SWEETENED CONDENSED WHOLE MILK AND SWEETENED CONDENSED SKIM-MILK. (a). Forewarming or Heating in the Hot Wells. The forewarming of the fluid milk in making the above pro- ducts is subject to many differences in practice. In some cases the heating is carried only to 140° to 160° F. This method has the advantage of giving the finished product a minimum amount of color. It has the disadvantage of not reducing the bacterial flora as much as is usually desirable. It may have the further disadvantage of not dissolving the added sugar, as completely as it should be. The more common and the preferable practice is to heat the fluid product up to 200° to 210° F. If the heating is done carefully, a finished product can be produced that i§ of very satisfactory color, and at the same time the disadvantages of the first method named can thus be largely overcome. It is recommended that no sugar be added to the first hot well in making up a batch. The total sugar making up 'a batch can be divided between the remaining hot wells, except that the final addition of sugar necessary for standardizing the batch can be added to the last hot well. Both the plain and jacketed type of hot wells are used in making sweetened condensed milk. The operating advantages are in favor of the jacketed type, as in the case of unsweetened condensed milk. The disadvantage is in the first cost of the latter. (b). The Operation of the Vacuum Pan Upon Sweetened condensed milk. The operation of a vacuum pan upon sweetened condensed milk, is in all essential respects, the same as in the case of un- sweetened products. The principal difference is in the con- centration of the two products. (c). Striking the Batch, in the Case of Sweetened Condensed milk. Chapter XII contains detailed information as to the specific gravity of different kinds of sweetened condensed milk. Several methods for ascertaining the end point, and which depend for their success upon the judgment of the operator, are sometimes Sweetened Condensed Milk 717 used, but none of these are reliable, and the same should be de- pended upon only as an aid, and not as a means. The most satisfactory method devised up to this time, is by means of hydro- meters, suitably graduated and properly used. The striking operation requires skill, speed and care. A vacu- um pan seven feet in diameter removes water at the rate of about 100 pounds per minute. Near the end of the run, the re- moval of this amount of water per minute in a batch of about 15000 pounds of whole milk, would increase the total solids at the rate of one per cent per minute. (d). To Finish the Pan Batch when Making Sweetened Con densed Milk. Proceed as in the case of unsweetened condensed milk. The practice of cooling the product in the pan may be advantageously followed, but the temperature is seldom lowered here, under 120° F. Sweetened condensed milk should not be allowed to remain in the pan under heat after the batch is done. This will super- heat and thicken the product, and in many cases render it un- salable. The method of handling the condensed product, after it leaves the pan, is fully described in Chapter XII. The precautions in pan operation are the same as in the case of unsweetened condensed milk, and the operator should thor- oughly familiarize himself with every condition requisite for suc- cessful operation. (e). To Forewarm and Condense Liquid Dairy Products, Other Than Unsweetened and Sweetened Condensed Milk The vacuum pan can be used to condense any liquid dairy product, as well as unsweetened and sweetened condensed milk, many of which are of great commercial and economical impor- tance. These products can be reduced to a liquid, semi-liquid, or solid state. Ice cream mix is the most recent product to be added to the list, and the process for making this in the vacuum pan is sub- ject to patents now pending by one of the authors'' and one of his brothers By this process a superior quality of product can be obtained, besides the numerous economic advantages. The tem- peratures during no part of the operation are allowed to exceed 718 The Vacuum Pan 140° F., so that the natural flavors are fully retained. The temperature used in condensing the mix is the same as that used in pasteurizing, therefore the pasteurizing and condensing are combined in one operation. The principles involved are the same as in the case of other dairy products. The whole milk, butter or cream, sugar and the gelatin are all added in the hot wells, and condensed together in the vacuum pan. The striking point varies obviously with the composition of the product being manufactured. The specific gravity of different ice cream mixes is given in Chapter XIII. Condensed buttermilk is a product of growing commercial importance. It is condensed to a semi-paste condition. The heavy viscosity is due both to its concentration, and to slightly superheating before drawing it out of the pan. The usual method is to heat the buttermilk in the hot wells at 145° F., to condense at the pan temperatures usually used in the case of unsweetened condensed milk products, and finally to superheat in the pan to 160° F. It is run while hot, directly into shipping barrels, and it is cooled after being barreled. The specific grav- ity of this product at various concentrations is given in Chap- ter XIV. Malted milk is an American product of world wide distribu- tion and of considerable commercial importance. It is finished in a special pan wherein it is reduced to a dry state, before removing it from the pan. Whey used to make milk sugar can frequently be condensed to a semi-liquid or dry state before shipping to a central refining plant. The advantage is in the superiority of the product, and the saving in transportation charges. REFERENCES. 1 Hunziker, O. F., La Grange, 111. "Condensed Milk and Milk Powder," p. 87, 3rd edition. 2 Snow & Leland. "The Steam Engine," 1908, p. 88. 3 Poole. "The Calorific Power of Fuels." * Gill, A. H. "E'ngine Room Chemistry," p. 72. " Report, U. S. "Liquid Fuel," Board 1904. « Babcock and Wilcox Co. "Steam." 'Hamilton, Molkerie-Zeitung, No. 16, 1901. * Mojonnier. T. CHAPTER XIX EVAPORATED MILK ITS STERILIZATION AND PHYSICAL AND CHEMICAL CONTROL. In plants manufacturing evaporated milk, the proper steriliza- tion of the product is one of the most important of the operations. Conditions that affect sterilizing time and temperature vary great- ly over the course of the year, and frequently from day to day. Unless the factors that affect sterilization are properly under- stood and in turn applied in daily practice, the product will be irregular in its physical properties or it will be both irregular and develop spoilage after manufacture. The ideal aimed at in this chapter is to recommend methods and processes for sterilizing evaporated milk whereby the phys- ical properties of this product, namely the viscosity, flavor and color, can be kept uniform at all times and under all conditions ; and at the same time insure proper sterilization so that spoilage Mall be entirely eliminated. To insure these results operations going back to the farms need to be imderstood and closely watched from day to day, and the knowledge thus gained ap- plied in daily practice. The two-fold purpose of sterilization should be kept in mind at all times. First, to insure the keeping qualities of the product ; and second to impart to the product the physical properties referred to above that are demanded by trade, custom, or personal preference. The Choice of Sterilizer. — Several makes of sterilizers are upon the market, most of which if properly operated can be used with success. These are offered in a large range of sizes to suit all ranges of production. Two common types of sterilizers that are extensively used are illustrated under Figs. 166 and 167. Many of the problems involved in the operation of the sterilizers are purely mechanical, and must be determined by local con- ditions. Other phases of the subject will be discussed in this chapter. [719 1 720 Evaporated Milk The Sterilizing Process. — The time and temperatures used in sterilizing, and the mechanical manipulations of the sterilizers during the sterilizing process are subject to many needless fluctuations in practice. Space will not be consumed to discuss Tig. 166. Fort Wayne Sterilizer. Courtesy The Engineering Co. the relative merits of these different methods, but the discussion will concern only the process that the authors know from wide experience to give satisfactor.y results at all times. Furthermore the modern tendency is to standardize the sterilizing process not only as between the plants of the same manufacturer, but in a larger sense, as between the plants of different manufacturers. The process in brief is as follows : Coming-up time. — A minimum of 15 minutes, and a maxi- mum of 20 minutes should be taken to raise the temperature in the sterilizer from room temperature, to the temperature at which the milk is to be sterilized. This is commonly known as Sterilization 721 the "coming-iip time." Where water is used in the sterilizers during the processing uniform results may be obtained with 15 minutes coming up time. When live steam is used, the best results are obtained when 20 minutes elapse. The relation be- tween minutes in coming up and the temperature in the sterilizer is indicated both for the 15 and 20 minute intervals in Table 130. Pig-. 167. BerUn Sterilizer. Courtesy Berlin Canning Machinery Works. As indicated in the table the temperature should be at 190° F. at the end of 5 minutes when 15 minutes is the coming up time used, and at the end of 10 minutes when 20 minutes is used. The rate of increase is more rapid between the initial tempera- ture and 170° F., than it is from 170° F. to 240° F. During the last 10 minutes of the coming up time the increase should be at the rate of 5° F. for every minute. Influence of Speed of Sterilizer Reel. — The speed at which the sterilizer reel is operated has a very important bearing upon the sterilizing operation. The faster the reel is operated the more rapidly the milk will heat inside of the can, and also the more rapidly it will cool at the end of the run. Too rapid reeling tends to destroy the viscosity, and to produce a grainy finished product. Too slow reeling produces a clabbery product — one that is sterilized with difficulty, and that cools very slowly. The proper speed of the reel is from six to ten turns per minute depending upon the diameter of the sterilizer. A sterilizer of 96 case capacity produces the best results at six turns per minute. A 30 case sterilizer at ten turns per minute. 722 Evaporated Milk TABLE 130. Relation Between Temperature and Time When Coming Up in Sterilizers. Minutes after turning on steam. Temperature in sterilizer at corresponding minute. Degrees F. 70 Minutes after turning on steam. Temperature in sterilizer at corresponding minute. Degrees F. 1 6 11 195 1 2 90 7 12 200 3 110 8 13 205 2 4 130 9 14 210 5 150 10 15 215 3 6 170 11 16 220 7 175 12 17 225 4 8 180 13 18 230 9 185 14 19 235 5 10 190 15 20 240 The Addition of Water to the Sterilizers. — Adding water to the sterilizers before turning on the steam usually helps to pro- duce more uniform sterilization, but the practice is not a universal one. The proper spacing of the cans in the trays and in the crates is a factor that influences uniformity of sterilization. The spacing and the placing of the cans should be such as to facilitate the transmission of the heat equally to all of the cans in the batch, When water is added just enough should be used to cover all of the cans in one position of the reel. Savings in coal can be affected by storing the hot water between the sterilizer runs in a suitable tank, so placed that the water will run by gravity back into the sterilizer at the beginning of the succeeding run. The above points are illustrated under Fig. 168. Holding" temperature. — The minimum temperature recom- mended is 240° F., and the maximum 245° F., with the proper holding time. Holding time. The holding time never should be less than 15 minutes with the temperature never under 240° F, Sterilization 723 TO SLNNLR-^ '^VALVE TO TANK - Pigr. 168. Sterilizer Arrangrement When Using Hot Water in Sterilizing'. Cooling time. — From 15 to 20 minutes, depending upon the temperature of the water. The cooling should be continued until the temperature of the milk throughout the batch is between 70 and 80° F., or about room temperature. If all the factors affect- ing sterilization are properly controlled the sterilizing process can be kept between the following limits at all times : — Coming up time Holding temperature Holding time Cooling time mnnmum maximum yi5 minutes minimum "4 20 minutes maximum (240° F. \245° F. 1 15 minutes minimum I 20 minutes maximum !15 minutes minimum 20 miiiUtes maximum 724 Evaporated Milk The sterilizing process, as recommended above, from the time the steam is introduced until the cooling of the batch has been completed is shown in the graph represented over Fig. 169. s 15 ZO 25 lO 15 30 35 40 45 SO TIMEINMINUTE.5. Tig. 169. The Relation Between Coming- TJp Time, Holding Temperature, Holding- Time, and Cooling- Time in Sterilizing Evaporated Milk. Controlling Equipment 725 MOJONNIER EVAPORATED MILK CONTROLLER. This apparatus was designed especially to provide a means for controlling all the factors that atfect the sterilization of evapo- rated milk. It is illustrated under Fig. 170. To 0. W. Mojonnier was granted U. S. patents covering the fundamental processes underlying its operation. Its application will be described further in this chapter. Fig-. 170. Mojonnier Evaporated Milk ControUer. Factors That Influence the Heat Coagulation of Milk. — The starting point of a good finished product is a good supply of fresh milk. The acid content should be kept as low as possible at all times. At certain seasons the processing is very difficult even 726 Evaporated Milk with a milk supply of low acid content. This is due to the sev- eral factors that influence the coagulating point of casein and albumin as follows : (a) . Effect of acid content upon the coagulating point of milk. — The ease with which sour milk curdles when heated is a fact of common knowledge. Advantage of this fact is taken in the manu- facture of cottage cheese. The difficulties encountered in steril- izing evaporated milk as a rule increase as the content of titra- table acidity increases. This is particularly true if the titratable acidity is due in part, at least, to the decomposition of the milk sugar into lactic acid by bacterial growth. It has been proved by several investigators (among whom can be mentioned Rice,^ and Sommer and Hart-) that the percentage of titratable acidity in milk as drawn from the cow, varies be- tween rather wide limits. Sommer and Hart found no definite relation between the titratable acidity in freshly drawn milk, and the heat coagulation of the same. The summary of their inter- esting experiments are contained in Table 131. TABLE 131. Summary of Results. Sommer and Hart Upon Relation of Titratable Acidity and Heat Coagulation, No. of cows tested Titratable acidity in per cent. No. samples that tested over .18 per cent No. samples testing over . 18 per cent that coagu- lated within 20 minutes No. samples that tested under .18 per cent No. samples testing under .18 per cent Date Min. imum Max- imum Aver- age that coagu- lated within 20 minutes May 8, 1919 26 .120 .257 .185 15 5 11 6 May 10, 1919 30 .131 .241 .196 14 7 16 7 May 16. 1919 30 .102 .203 .167 16 11 14 6 Total 86 .178 45 23 41 19 In the above experiment 51.2 per cent of the samples testing above .18 per cent of acid coagulated under 20 minutes when heated in a sealed glass tube held in a xylene vapor bath at a temperature of 136° C. Likewise 46.4 per cent of the total sam- ples testing under .18 per cent of acid, coagulated in less than 20 minutes. These results show that when an acidity test is depended upon entirely when grading milk that is to be used for making evapo- rated milk, an entirely false criterion of its value may be ob- tained. Coagulation Control 727 The quantity of acid required to influence the coagulating point of milk is too small to permit of its control by titration methods. High titratable acidity in fresh milk cannot be de- tected by the senses of taste or of smell. To a trained person even small quantities of acid produced by bacterial growth can be readily detected by the senses of taste or of smell or by both. The most concealing factor to the sense of smell is the tempera- ture of the milk — the colder the milk the more difficult it be- comes to detect any acid development in the milk. In practice unquestionably the best method of grading milk at the factory's intake is by means of the senses of taste and smell, both intelligently applied by a trained person. This in turn should be supplemented by careful observation of the be- havior of the milk accepted, under the processes to which it is to be subjected. Any indication of milk taken which reacts un- favorably under heat, should lead at once to increased vigilance at the intake. If it should be desired to determine the coagulability of the milk from individual cows, cans or herds this can be done by using the method devised by Sommer and Hart, or by means of one or more of the methods given in Chapter XVII of this book. A means is thus available for tracing trouble to the original source. The acid content of the fresh product increases in direct pro- portion to the degree of condensation. Obviously the higher the degree of condensation the greater Avill be the acid content of the evaporated milk before sterilizing the same. Mclnerney ■'' made a careful study of the influence of the acid content upon the coagulating point of milk. To 100 cc. of milk there Avas added sufficient N/10 lactic acid to build up the total acidity to the test desired. "The mixture of milk and acid was then heated in the steam bath until the milk coagulated, and the temperature was noted. The amount of acid required to co- agulate the milk decreased as the temperature increased from 70 to 180° F." The composition of the milk studied is not reported. Typical results covering these kinds of milk are given in Table 132. 728 Evaporated Milk TABLE 132. Influence of Acid Content Upon the Coagulating Temperature of Milk. Skim-milk testing Whole milk testing Pasteurized whole milk .145 per cent acid .140 per cent acid testing .150 per cent acid Total Coagulating T otal Coagulating Total Coagvilating acid temperature .i cid temperature acid temperature Per cent °F Pe r cent op Per cent op .580 70 530 73 .560 66 .480 104 480 87 .500 85 .430 145 440 110 .480 83 .390 150 400 110 .450 95 .340 155 350 147 .410 96 .280 170 310 162 .400 104 .250 185 270 175 .390 .370 .360 .320 110 140 150 160 "These experiments show that milk containing 0.57 per cent acid (in terms of lactic acid) will, on the average, precipitate at a temperature between 60° to 65° F. Milk containing 0.50 per cent acid will curdle at 75° to 80° F., 0.40 per cent at 100° to 110° F., 0.35 per cent at about 150° F. and 0.25 per cent acid in milk will not cause coagulation until heated to 180° F. As shown in Table 132 the small drop in acidity between 0.40 to 0.35 per cent makes a greater range of temperature than between any other two points of acidity studied. As shown in the experiments, a decrease of 0.05 per cent acid at this particular stage requires nearly a 50° F. range in temperature to produce coagulation as 0.40 per cent acid in milk will curdle at about 100° F. Avhile 0.35 per cent acid in milk will not produce curdling until heated to at least 150° F." (b). Influence of the nitrogenous constituents upon the coagu- lating point of milk. — From the standpoint of the manufacture of evaporated milk all of the nitrogenous constituents of milk are of interest and divide themselves into three separate and distinct substances or groups of substances, as follows: (1) Casein which coagulates in the cold in the presence of acid only. It also co- agulates under pressure at temperatures above the boiling point of water, in either alkaline, neutral, or slightly acid mediums. (2). Albumin which coagulates in part under heat in normal milk, and completely in an acid medium. (3) Other nitrogenous constitu- ents which are not precipitated either by acids or by heat. This group probably includes quite a number of different chemical en- Coagulation Control, 729 titles. All of the above substances dissolve in weak alkaline solu- tions, after having been coagulated. In processing evaporated milk the casein and albumin are the products of the greatest importance. These two substances vary in milk both in the total percentages of the two present, as well as in their relative percentages. Albumin predominates especially in colostrum milk, which ac- counts for the ease with which such milk is curdled by heat. Hunziker * reports the composition of the nitrogenous constituents of the milk from three cows at monthly intervals during an entire lactation period, as shown in Table 133. The influence of egg albumin upon the coagulating point of evaporated milk is illustrated by the following experiment. To one six ounce can of unsterilized evaporated milk there was added one cc. and to a second can four cc. of fresh egg albumin. After sterilizing under standard time and temperature along with a control can to which nothing had been added, both were com- pared with the blank can. The can to which one cc. of the egg albumin had been added showed a considerable increase in vis- cosity, and tliat to whicli five cc. had been added showed a very large increase in viscosity over that of the blank can. This in- dicated a large decrease in the coagulating point due to the added egg albumin. TABLE 133. Effect of Period of Lactation on the Percentages of Albumin, Casein and Total Proteid in the Milk of Three Cows. feriod of Lactation Albu- min Cow No. 1 Cow No. 2 Cow No. 3 Case- in Total Proteids Albu- min Case- in Total Proteids Albu- min Case- in Total Proteids First 14 milkings .98 .57 .53 .52 .56 .55 .53 .86 .75 .73 .77 .91 3.18 2.55 2.27 2.54 2.51 2.62 2.65 2.62 2.79 2.84 3.02 3.08 4.16 3.12 2.80 3.06 3.07 3.17 3.18 3.48 3.54 3.57 2.79 3.99 1.59 .55 .47 .48 .50 .48 .54 .76 .60 .56 .59 .61 3.81 2.47 2.37 2.28 2.36 2.26 2.30 2.50 2.66 2.73 2.73 2.88 5.40 3.02 2.84 2.76 2.86 2.74 2.84 3.26 3.26 3.29 3.32 3.49 1.72 .58 .51 .55 .60 .60 .73 .62 .64 .72 .82 4.46 2.88 3.06 3.25 3.05 3.05 2.96 2.99 2.94 3.30 3.39 6.18 3.40 2nd month 3.57 3.80 3.65 5th month 3.65 6th month 3.69 7th month 3.61 8th month 3.58 9th month 4.02 10th month 4.21 lltn month It becomes obvious from the above facts that milk high in colostrum when made into evaporated milk will very likely have 730 Evaporated Milk a low coagulating point, and therefore it will be very difficult to sterilize properly. Sterilizing difficulties due to the above causes are of comparatively rare occurence where the proper control is maintained over the milk supply. In the mixed milk from many herds the variations in the percentages of the nitro- genous constituents are relatively small, especially where colo- strum milk is completely rejected. (c). Influence of the mineral constituents. — It has been long known that the addition of certain mineral salts, and other sub- stances, exert a marked influence upon the coagulating point of evaporated milk. In some cases the coagulating point is lowered. In others it is increased. One of the authors'^ by careful experiment determined the influence of the addition of various substances upon the coagu- lating point of evaporated milk. These substances were added in known amounts to six ounce cans of evaporated milk before sterilizing. The influence of the added substance was noted immediately after sterilizing. The results are given in Table 134. TABLE 134. Influence of Added Salts on the Coagulating Point of Evaporated Milk. Name of substance added to evaporated milk before sterilizing. Percentage of substance after adding to the evaporated milk. Influence of the added substances upon the coagulating point of the evaporated milk. Lactic acid .03 Large decrease in coagulating point Sodium chloride .... .03 Large decrease in coagulating point. Calcium chloride . . . .15 Large decrease in coagulating point. Impossible to sterilize properly. Magnesium chloride. .15 Large decrease in coagulating point. Impossible to sterilize properly. Sodium sulphate.. . . .15 Slight decrease in coagulating point. Sodium acid phos- phate, NaHz PO4 .15 Large decrease in coagulating point. Impossible to sterilize properly. Ammonium chloride .15 Large decrease in coagulating point. Impossible to sterilize properly. Tri sodium phos- phate Nas PO4 .03 Large increase in coagulating point. Sodium ammonium acid phosphate . . . .03 Large increase in coagulating point. Ammonium phosphate .03 Large increase in coagulating point. Sodium bicarbonate. .006 1 oz. per 1000 lbs. raised coagulating point 1° F. I Coagulation Control 731 All the chlorides tested greatly decreased the coagulating points. Sodium sulphate also decreased the coagulating point. Sodium acid phosphate decreased the coagulating point, while other phosphates increased it. Sodium bicarbonate increased it greatly. The small amounts required to influence the coagulating point shows how delicate is the balance, and how great is the in- fluence of the content of mineral salts. Sodium bicarbonate is in most respects the best product to use when it may be necessary to add some substance to the milk after other means have failed, in order to reduce the coagulating point. It is dependable, and of low cost. Its principal objection is the fact that it produces a large volume of carbon dioxide gas when it decomposes. This retards the condensing operation, since it makes it necessary for the vacuum pump to remove the gas that is formed. If the sodium bicarbonate is added to the evaporated milk after condensing, the gas is released during the sterilizing operation, and this causes the ends of the cans to bulge, giving the appearance of the cans being "swells" due to spoilage. Carbon dioxide is very soluble in cold water, so that moderate amounts that may be released during the sterilizing process are soon absorbed after the evaporated milk has cooled to room temperature. The practical limit of sodium bicarbonate to add after condensing is four ounces per 1000 pounds of the condensed product. When the sodium bicarbonate is added to the milk in the hot wells before condensing the practical limit should not exceed twelve ounces per 1000 pounds of finished product. The best plan is to add the greater part of the total amount required to the hot wells before condensing and to add only the final small amount required to standardize the coagulating point, to the condensed product before filling it into the cases, and there- fore before sterilizing. The use of an excessive amount of sodium bicarbonate also increased the color of the finished product after sterilizing. Every argument is in favor of its moderate use. Tri-sodium phosphate has the disadvantage of greater cost, but it does not produce any gases when added to milk. There may be conditions under which it can be used to advantage. Theoretically it would appear possible to utilize the above facts in standardizing the coagulating point of evaporated milk 732 Evaporated Milk during the process of manufacture. This is only partially possible. Lactic acid cannot be used because its action is too violent, and its use is attendant with too many dangers. All the chlorides named cannot be used principally because of their bitter taste. More satisfactory means are known for decreasing the coagu- lating point than by adding foreign substances. These means will be discussed elsewhere in this chapter. The use of sodium bicarbonate affords a very satisfactory means for increasing the coagulating point. This will be further described in this chapter. Sommer and Hart- made a careful study of the influence of the mineral constituents upon the coagulating point of milk, and draw the following conclusions which in the main confirm the results reported above : — ''In most cases coagulation can be prevented by the addition of citrates or phosphates, the coagulation being due to an excess of calcium and magnesium. However, in a few cases the addition of citrates or phosphates did not prevent coagulation, but rather hastened it. In these cases the addition of the proper amounts of calcium salts prevents coagulation, or at least raises the coagulating point. ' ' "From the data in Tables 135 and 136 we see that the calcium and magnesium are balanced by the phosphates and citrates of the milk practically in gram equivalent amounts. The balance of the four constituents, calcium, magnesium, citrates and phos- phates, largel,y determine whether a milk will coagulate or not. If calcium and magnesium are in excess, the milk will coagulate upon heating. If calcium and magnesium are properly balanced with the phosphates and citrates, the optimum stability obtains. If posphates and citrates are in excess, coagulation will also result." ' ' Thus the coagulation of a milk sample on heating may be due either to an excess or a deficiency of calcium and magnesium. We may explain this in the following manner. The casein of the milk is most stable with regards to heat coagulation when it is in combination with a definite amount of calcium. If the calcium combined with the casein is above or below this optimum the casein is not in its most stable condition. The calcium in the milk distributes itself between the casein, citrates and phosphates chiefly. If milk is high in citrate and phosphate content more Coagulation ControIv 72>?> calcium is necessary in order that the casein may retain its optimum calcium content after competing with the citrates and phosphates. If the milk is high in calcium there may not be sufficient citrates and phosphates to compete with the casein to lower its calcium content to the optimum. In such a case the addition of citrates or phosphates makes the casein more stable by reducing the calcium content. The magnesium functions by replacing the calcium in the citrates and phosphates." "In most cases the coagulation is due to an excess of calcium and magnesium. It is possible to balance this even by citrates, phosphates, carbonates and other salts. It is also stated that danger of coagulation may be avoided in the actual practice of condensing milk by controlling the preheating period, using higher temperatures. This may have the effect of lowering the soluble calcium content by precipitating part of it as insoluble calcium phosphate." In the experiments of Sommer and Hart twenty-five out of thirty which coagulated contained an excess of calcium and magnesium over citrates and phosphates. Those which liad the lowest excess did not coagulate. TABLE 135. Balance Between Calcium and Citrates. 25 CO. milk plus Coagulation time M/2 calcium acetate M/2 sodium citrate H„0 cc. 0.0 cc. 0.0 cc. 1.6 Min. 4 0.4 0.0 1.2 V2 0.4 0.2 1.0 40. 0.4 0.4 8 40. 0.4 0.6 6 21/4 0.4 0.8 4 2 734 Evaporated MiIvK TABLE 136. A Sample in Which Calcium Prevents Coagulation. 25 cc. Milk Plus Coagulation time M/2 calcium acetate M/2 sodium citrate H,0 cc. 0.0 cc. 0.0 cc. 0.8 Min. 1% 0.2 0.0 0.6 20 0.2 0.1 0.5 iy4 0.2 0.2 0.4 1 0.2 0.3 0.3 V4 0.2 0.4 0.2 V4 (d). Influence of concentration. — The degree to which the fresh milk is condensed has a large influence upon the coagulating point of the evaporated milk. This is illustrated by the experi- ment reported by Hunziker'' as shov^^n in Table 137. TABLE 137. Showing the Increase of the Per Cent of Acid as the Concentration of the Evaporated Milk Increases and Its Effect on the Curdling of the Casein. Lot No. Concentration Per cent acid Condition of casein 1 1.58:1 .34 Not precipitated 2 1.74:1 .34 Not precipitated 3 1.9 :1 .40 Not precipitated 4 1.99:1 .43 Not precipitated 5 2.11:1 .48 Small lumps of curd 6 2.25:1 .54 Large lumps of curd In normal evaporated milk at a concentration around 7.80 per cent of fat and 25.50 per cent of total solids, every 20 pounds of water added or removed per 1000 pounds of the condensed product, lowers or raises, as the case may be, the coagulating point I'^F. This is an important factor that can be used in con- trolling the sterilizing process. Coagulation ControIv 735 In uormal evaporated milk the influence of concentration has been a large determining factor in establishing the present standards which control the manufacture and sale of this product. The factor of concentration was studied by Sommer and Hart^. They concluded from their experiment that "not only the con- centration of the casein influences the coagulating point, but also the concentration of the serum." The intricacy of the above reactions is well illustrated by the case of the salts of sodium. Sodium chloride and other sodium salts when added to evaporated milk greatly lowers its coagu- lating point, while sodium bicarbonate and certain other sodium salts have exactly the opposite effect. Much remains to be learned regarding the influence of both basis and acidic radicals upon the coagulating point of milk by heat. (e). Influence of products of bacterial growth, other than acid. — A considerable number of bacteria are known that have the power to produce rennet or rennet like substances, which have the power to curdle milk. The action of rennet upon milk forms the basis of the cheese industrj^, since this makes it possible to coagulate the casein at a low temperature, and in the presence of a low acid content. Rogers' reports interesting experiments that prove the above statements. He states: "Milk, inoculated with a small amount of bacteria known to produce rennet actively, was held at room temperature for three hours. With this was held part of the milk without inoculation which, when evaporated to the standard con- centration, curdled at a temperature of 240 degrees F. That inoculated and held three hours before evaporating, curdled at 226 degrees F., although the acidity was identical with the uninoculated fraction." The results of his experiments are shown in Table 138. The presence of rennet producing type of bacteria is largely favored by unsanitary conditions either at the farms where the milk is produced, or in the plant where the fresh milk is manufactured into evaporated milk. Unclean milk pails and milk cans are the most prolific cause of trouble upon the farm. Unclean utensils, milk pumps and milk pipe lines are the most prolific cause of trouble in the plant. The rigid enforcement of 736 Evaporated Milk TABLE 138, Effect of Rennet Forming Bacteria on Curdling Temperatures. Inoculation Time of action (hours) pH Coagulation temperature degrees F. None Rennet-forming bacteria, 10 cc. 3 1^ 6.33 240.4 226.4 3 6.33 226.4 None 2 246.2 Rennet .0175 1 226.4 gms. 2 213.6 sanitary rules at all points will do more than anything else to eradicate a trouble of this kind in an evaporated milk plant. (f). Influence of method of forewarming in the hot wells. — The method of forewarming the milk in the hot wells exerts a large influence upon the coagulating point of the flnished product. This fact is of large practical value in the manufacture of various condensed milk products, and mention is made of it in different chapters of this book. The exact cause of this action is not fully understood because of lack of experimental proof. Sommer and Hart, just quoted, state that this may be caused by the precipitation of part of the soluble calcium content into the insoluble calcium phosphate, but no experimental proof is submitted, Tricalcium citrate when freshly prepared is readily pre- cipitated upon heating, probably due to decreasing solubilities at increasing temperatures, and the theory is frequently advanced that this is the cause of the changes produced in milk by fore- warming. Experimental proof is lacking here also, and practical evidence is contrary to this view. Further reference will be made to this matter in another part of this chapter. The action of heat upon the coagulation of the albumin in the milk may very readily be the most important factor controlling this action. It has long been known that the extent of the coagulation of albumin by heat varies with both the temperature and the time of exposure of the milk to the heat. The liigher the temperature and longer the time of heating, the more of the albumin will become insoluble by heat. Coagulation CoNTRoiy 737 Cavanaiig'li and Latzer^ report the following amount of albumin precipitated under different conditions of heating, the results being the average for ten experiments. When heated to boiling ,37 per cent albumin precipitated. When boiled for five minutes .42 per cent albumin pre- cipated. When heated at 15 lbs. pressure for 80 minutes .44 per cent albumin precipitated. The above results were obtained by difference from their published results. When milk is heated no apparent separation or coagulation of the albumin takes place, but it undergoes a change that causes that part of it wliich has changed to separate with the casein when acid is added. The values given above represent the amount of albumin which separated along with the casein when acid was added in making the determination of acid insoluble protein. The preponderance of evidence at the present time is that the changes in the albumin content of the milk by heating may be largely responsible for the differences in the behavior of evapo- rated milk in sterilizing, which milk had been previously heated differently in the hot wells. Heating- of the Milk in the Hot Wells. — As already noted, when milk is properly heated in the hot wells, it undergoes certain changes which play an important part in the sterilization of evaporated milk. Unless the milk is properly heated in the hot wells, there is every opportunity for the milk to undergo certain other chemical changes, Avhich will have a very bad effect upon the ultimate product. The reasons for these other changes are not definitely understood at the present time, but all the evidence is in favor of the view that when the heat is improperly applied to the milk in the hot wells, certain chemical changes occur in the casein and albumin molecules. The extent of these changes follow closely the law of mass action. That is, when the steam is introduced into the milk at a high pressure, or in large volumes, the agitation of the milk at the point of the introduction of the steam is not rapid enough to transmit the heat uniformly to all parts of the milk in the hot Avell. The result is that the local 738 Evaporated Milk action of the steam upon the milk is sufficiently great to overheat the milk beyond the coagulating temperature of the casein itself. The above unfavorable effect is almost negligible v^here jacketed hot wells are used, and the worst effect manifests itself where plain hot wells are used — that is, where the milk is heated in the hot wells by live steam. By using the proper care, it is possible to heat the milk in plain hot wells, using live steam only, without causing any injury to the milk. It has been learned by experience that no bad results follow. when eight minutes are taken to forewarm one thousand pounds of fresh milk to the desired temperature in the hot wells. The only safe method to follow is to place a pressure reducing valve upon the steam feed line which is used to supply the hot wells. This valve should be set to operate at a pressure not in excess of 10 pounds per square inch. Where the jacketed hot wells are used, it is best to bring the milk up to about 170° F., and then to complete the heating from that point up to the right temperature by means of live steam, introduced directly into the milk. In a number of cases, the milk is passed through special heaters on the way to the hot wells and forewarming is then completed in the hot wells with live steam. As a rule, this is a very satisfactory method. Steam Distribution in the Sterilizer. — Even distribution of steam in the sterilizer is necessary, no matter what style of sterilizer is used, or whether superheated water or steam alone is used for sterilizing. A frequent cause of uneven sterilization lies in the fact that the perforations in the steam distributing pipes become enlarged, due to the wearing effect of the steam while passing through the perforations. This is especially likely to be the case where the steam distributing pipes are made of thin brass tubing. It is recommended as far as practical, that brass pipe, iron pipe size, be used for this purpose. There is much less danger from enlarging of the perforations when this pipe is used, than when the thin brass tubing is used. It is especially suggested that iron pipe never be used for this purpose, although some makes of sterilizers are noAv furnished with the distributing pipe of iron. When iron is used, the openings are likely to be- come enlarged not only from the action of the steam, but also from the rusting of the iron. Uniforini SturiIvIzation 739 It frequently happens that the cap may come off of one of the steam pipes, or the pipes may become disconnected at the inlet, so that for all of the above reasons, it is very desirable to check up the different sterilizers very carefully from time to time. The Evaporated Milk Controller affords a particularly efficient means for checking up the evenness of sterilization. This is accomplished by means of the viscosimeters which accompany the Controller. Detailed instructions for making the viscosity tests will follow further in this chapter. When checking up by means of the viscosimeter, it is sug- gested that at least three sets of cans be taken out of each sterilizer. The first set is to be taken from the top of one section in the case of a Fort Wayne Sterilizer, and from the top of the cage in the case of a Berlin Sterilizer. The second set is to be taken from the middle of the section or cage, and the third set from the bottom of the section or cage, in the two respective sterilizers. In each case, one sample is to be taken from near each of the two ends, and one from the center of the section or cage, making a total of nine samples in all. By following this method, it becomes possible to get an accurate check upon the distribution of the steam in the different parts of the sterilizer. TABLE 139. Determining Steam Distribution in the Sterilizer. Location of Sample in Sterilizer Viscosity retardation Right end 4 cans from end, top row of cans 115° Right end 4 cans from end, center row of cans 100° Right end 4 cans from end, bottom row of cans 120° INIiddle of cage, top row of cans 132° Middle of cage, center row of cans 175° Middle of cage, bottom row of cans 265° Left end 4 cans from end, top row of cans 150° Left end 4 cans from end, center row of cans 65° Left end 4 cans from end, bottom row of cans 170° As the figures show in the above example, the sterilizer in question cooked the milk considerably heavier in the center of the cage than at the two ends, particularly the inside cans at the two ends. By changing the steam circulation, and particularly by watching the level of the water in the sterilizers, it was possible to improve the uniformity of the sterilization. 740 Evaporated Milk Standardization for Fat and Total Solids. After the milk has been condensed and cooled, the next step is to test the milk for butter fat and total solids. If the plan is followed of standardizing the finished product, both for fat and total solids, this should be done before the samples are taken out for the tests upon the Controller, In case that the plant follows the plan of standardizing with water only, the milk should be standardized down with the water to the required basis, and the samples then taken out for the tests upon the Controller. It is very important to coordinate the tests upon the Mojonnier Tester for butter fat and total solids with the tests upon the Evaporated Milk Controller. If this is done, it will be possible to obtain uniform results both from a chemical and physical standpoint upon the finished product. Ten Per Cent Sodium Bicarbonate Solution. Prepare as follows : (1). Weigh bottle empty, upon Torsion Balance to .01 ounce. (2). Add 3 ounces bicarbonate of soda to the bottle. (3). Add 27 ounces warm water to the bottle. Shake thoroughly until the bicarbonate is all dissolved. Draw out as needed into the dispensing bottle, filling the same not over half full. Keep remainder tightly corked in the stock bottle until needed. Should the bicarbonate crystallize out, prepare a new lot. If prepared according to the above directions, the solution will contain exactly 10% sodium bicarbonate. How to Add Sodium Bicarbonate to the Sample Cans. — Arrange in a row five open-top cups, marked— X-1-2-3-4. These cups are furnished with the Controller. Cup marked X is blank, to which nothing is added. To cup marked No. 1 add one charge of sodium bicarbonate from the dispensing burette. This is the amount contained between the upper two graduations on the burette. To cup marked No. 2 add two charges, to cup No. 3 add three charges. To cup No. 4 add four charges. Examination of the dispensing burette furnished with the Controller will indicate liOAV the above quantities are to be added; that is, the burette is graduated into four separate charges. The unit with one SteriIvIzation Control 741 siugle charge contains the equivalent of one ounce of sodium bicarbonate, to one thousand pounds of evaporated milk. Each successive charge is a multiple of this unit. In dispensing the bicarbonate solution, it is best not to fill the bottle more than half full. When filling the burette, the solution shoukl be allowed to flow into it slowly in order not to trap in the air. If air is trapped into the burette, it is difficult to remove it, and ill such a case it is best to run oat whatever solution may be in tJie burette, and to put in a new supply. Whenever the quality of the milk is bad, it may be necessary to add more than the above indicated number of charges of bicarbonate solution to the sample cans. In such cases any nmltiples of the above number of charges may be added. The ratio of ounces of bicarbonate to one thousand pounds of milk Avill remain the same, being increased simply by the number of charges added to each sample can. Preparing the Five Sample Cans for the Sterilizer. — After tlie five open-top cups have been treated with bicarbonate as indicated in the preceeding section, they are transferred to the Torsion Balance and exactly six ounces of milk are weighed into each cup. This can be done by taring the entire set of empty cups, and then weighing six ounces of evaj)orated milk into each separate cup. One set of five empty cans are now marked in the same manner as the cups to which the- bicarbonate solution was added, namely, as follows : X:= can containing no bicarbonate ; l=can containing equivalent of one ounce bicarbonate per thousand pounds of evaporated milk; 2=can containing equivalent of two ounces to one thousand pounds of evaporated milk; 3:=can containing equivalent of three ounces to one thousand pounds of evaporated milk and 4= can containing equivalent of four ounces to one thousand pounds of evaporated milk. The cans are now placed in pairs under the two can vent hole filler, furnished with the controller, and the cups with the milk and bicarbonate marked corresponding to the empty cans are now emptied into the filler. Care must be taken to keep the cans in the proper order. After filling, the cans are to be tipped, using preferably rosin solder. Should none of this solder be available, then great care ■42 Evaporated Milk must be exercised not to let any of the flux from the zinc chloride solder enter the cans. Zinc chloride flux has a very bad effect upon the milk, and will completely change the results. Sterilizing- the Five Sample Cans. — The five sample cans pre- pared as above are now ready for the sterilizer. Place these in the cage and fasten the lid securely, and also turn down the screws in order to hold all of the cans securely in place. Adjust the cage in the sterilizer by means of the thumb screw upon the right hand side in order to keep them from having end play. Close the sterilizer door securely so tliat no steam escapes during the sterilizing process. Be sure to provide circulation of the steam through the vent upon the pipe surrounding the thermometer. This little vent should be kept open during the entire sterilization operation. Fill the small pilot sterilizer to a point half way upon the gauge glass. Turn on the switch to start the motor in operation. Open the "steam start valve" and take five minutes to let the heat reach 190° F. or 3 upon the sterilizer scale. Then let the heat come up gradually from 190 to 240° F. or from 3 to 8 upon the thermometer, taking one minute for each 5° as indicated in the following table : TABLE 140. Relation Temperature, Scale Reading, and Coming-Up Time. Actual temperature in Fahrenheit degrees Actual reading upon thermometer scale Point at which mercury sliould be at any given time coming up. Minutes 240 8 20 230 7 18 220 6 . 16 210 5 14 200 4 12 190 3 10 Where sterilizing is done with steam only, without using superheated water, it is recommended twenty minutes be taken for coming up. The above table is arranged upon this basis. The table, liowever, can be readily adapted to a system requiring fifteen minutes for coming up, by taking five minutes to come up to the point marked 10 upon the table, or to 190° F. Viscosity ControIv 743 It is also recommended that in the pilot sterilizer, the samples be cooked to 243° F. and that the jump from 230 to 243° be made in two minutes. It is very important to know the exact second when the mercury column reaches 243°. The milk should be held at this temperature for fifteen minutes to the exact second. How to Cool the Five Sample Cans. — The instant that the clock indicates that the samples have been sterilized as indicated above, both discharge valve and cold water valve should be opened simultaneously. It is best to cool the five samples to about 75° F. This should take not to exceed five minutes, depend- ing upon the temperature of the water available. This is some- thing each operator will have to judge for himself. How to Test Sample Cans for Viscosity. — As soon as the sample cans are cooled in the sterilizer, as indicated above, the outside of the cans are dried ; and the cans are then opened and each can is placed in the proper position in the Mojonnier-Doo- little viscosimeter rack. It will be noted that the same scheme of marking the spaces upon the viscosimeter rack has been observed as in the case of marking the cans. It is very desirable to cool the samples to as nearly 75° F. as possible. If this is not done, the viscosity should be corrected for temperature, using the scale of corrections given in Table 141. Make the viscosity tests as follows : (a). Different sizes of balls are furnished, corresponding to the product that it may be desired to test for viscosity. A special viscosity ball is furnished in the case of evaporated milk, and this is not interchangeable with any other ball for this purpose. (b). Fasten one end of the wire in the knurled nut upon the top of the bent support, and the other end in the dial. Adjust the vertical position of the dial by raising or lowering, until the small lug on the bottom of the dial is in the proper position to engage the trip upon the right and side of the stand, (e). Adjust the horizontal position of the dial until zero degrees is in a Ijne with the pointer upon the front of the frame when the dial is balanced in the air. Center the dial in the open circle by means of the adjusting screws on the under side of the frame. Make a test for viscosity directly in the small size cans. 744 Evaporat£;d M11.K Properly center the can by means of the automatic arrangement provided for that puri)ose. (d). Lower the ball into the can of milk; turn the dial clockwise one revolution ; stopping when zero degrees upon the dial is in line with the pointer upon the front of the frame. Hold the dial in place by means of the lug and trip. When ready, sharply release the trip, note the degree where the dial stops, just before it starts upon the return round. This will occur after the dial has made one complete, and part of tlie second revolution. The degree at which the dial stops will represent the viscosity of the sample. The greater the viscosity, the larger the degree reading will be. The observed viscosity should always be reduced to a standard temperature. The higher the temperature the lower the viscosity will be or vice versa. The proper corrections to apply either above or below 75° F. are given in Table 141. A diflferent correction applies upon freshly sterilized evaporated milk, than upon the same product after it has reached the packing- room, in the usual methods of handling, as shown in the two tables. TABLE 141. Correcting Viscosity of Evaporated Milk to 75° F. STERILIZING ROOM PACKING ROOM Temp. Take off Temp. Add. on Temp. Add. Temp. Take off Temp. Add. on Temp. Add. Deg. Deg. Deg. Deg. Deg. on Deg. Deg. Deg. Deg. Deg. on F. R. F. R. F. Deg. R. F. R. F. R. F. Deg R. 65 25 76 .-> 89 24 60 15 75 88 10.0 66 22 77 4 90 25 61 14 76 1 89 10.5 67 19 78 (i 91 26 62 13 77 9 90 11.0 68 16 79 8 92 27 63 12 78 3 91 11.5 69 13 80 10 93 28 64 11 79 4 92 12.0 70 10 81 12 94 29 65 10 80 93 12.5 71 8 82 14 95 30 66 9 81 6 94 13.0 72 C 83 10 96 31 67 8 82 7 95 13.3 73 4 84 18 97 32 68 7 83 7.5 96 13.0 74 2 85 20 98 33 69 6 84 8.0 97 13.9 7.5 86 21 99 34 70 .) 85 8.5 98 14.2 87 22 100 35 71 4 8() 9.0 99 14 . 5 88 23 72 73 74 3 2 1 87 9.5 100 14.8 Record the viscosity of each of the sample cans tested, as indicated above. Further instructions will follow as to the method of applying information thus obtained. How to Test Cans for Color. — Just as soon as the samples have been tested for viscosity, they are to be moved under the colorimeter. The can that has been picked out as the standard vStkkiuzation Control 745 * should now be compared with another can from a run that was selected as being of the proper color, or it can be compared to any other standard that may be desired. If the milk is standard- ized for fat and total solids, and if the sterilization is kept within narrow limits as regards time and temperature of sterilization, the fluctuation from batch to batch should be very small. The above cire the largest factors that control the color. The color of evapo- rated milk also increases gradually with age. so that in selecting the stajidard. it is desirable to clioose freshly prepared goods. Correlations That Can be Used to Establish the Proper Steril- izing Method. — A number of very important relations have been correlated by careful experiment, and the facts thus known are used as a basis for establishing the exact temperature and time upon which any batch of evaporated milk may be sterilized, in order to obtain the best possible product. These relations are as follows : A retardation of 40"^ in the viscosity^ (a) 1 ounce solid sodium bicarbonate per 1000 pounds of unsterilized evaporated milk, standardized to 7.8 per cent butter fat and 25.50 per cent total solids; (b) or 1^ F. in the sterilizing temperature, at the holding point of 240 ' ¥. with the same coming up time ; (c) or one minute of time at a holding temperature of 240° F. ; (d) or 2° F. upon Ihe temperature to which the milk is heated in the hot wells under 212° F., (e) or 20 lbs. Avater per 1000 lbs. evaporated milk. The above viscosity relation holds only with viscosities above 50' or beloAv 300"^, upon the Mojounier-Doolittle Viscosimeter. The above are most important and fundamental facts to bear jji mind, and when once understood they will greatly simplify tlie adjusting of the correct process for sterilizing evaporated milk. This is best illustrated by the following example : A batch of milk has been standardized to 7.8 per cent butter fat and 25.50 per cent total solids. Total weight of evaporated milk in tlie batcli equals 24,000 lbs. The five sample cans from the pilot sterilizer tested for viscosity as follows : Can X=235° retardation Can 1=190-" retardation Can 2=150° retardation Can 3=105° retardation Can 4=: 70° retardation 746 EvAPORATi-D Milk • Now, it has been found by experience that 150° retardation is the proper viscosity for evaporated milk, just as it comes from the sterilizers. This refers to evaporated milk made for domestic consumption. Evaporated milk intended for export purposes should have a viscosity considerably higher than this, namely, around 200° retardation. It is not desirable to send out evapo- rated milk upon the market which contains as much as 150° retardation of viscosity. A considerable part of the viscosity which the milk has, when it comes from the sterilizers, is lost during the handling to which the milk is subjected from the time it leaves the sterilizers until it is ready to leave the shipping department. It is believed that the proper viscosity that the milk sliould have upon leaving the shipping department during the spring and summer months should be between 80° and 100° retardation. In the early fall and winter months, it should not be over 80°. The warmer the milk is during the handling opera- tions, either before it leaves the plant, or after it passes into the hands of the retailer, the less will be the viscosity of the milk by the time it reaches the consumer. Upon the other hand, it is equally important over the winter months to avoid excessive dscosity, as in that case the evaporated milk is likely to appear curdled when used in coffee, or even when diluted with water in the home. Referring back to the viscosity tests of the five cans, it will be seen that the can marked No. 2 is the one that most nearly approaches the standard aimed for, since this is found to have a viscosity of exactly 150° retardation. It is always desirable to eliminate the use of sodium bicarbon- ate as much as possible. In this particular case it will be possible to eliminate its use entirely, as indicated by referring back to the above correlations. That is, can No. 2 could be adjusted to have a sterilizing record of 243° F. at a holding time of fifteen minutes by adding two ounces of sodium bicarbonate per thousand pounds of evaporated milk. Upon the other hand, since it is more desirable to get along without using any bicarbon- ate, very nearly the same results can be obtained by sterilizing the batch at 241° F. for fifteen minutes holding time. It is not recommended that the holding time be reduced under fifteen minutes, as this is as short as it is desirable to make it. Under Strriuzation ControIv 747 the circumstances, tlie two alternatives in the above problem are first to add 2 ounces of bicarbonate per thousand pounds of finished product, or to reduce the sterilizing temperature 2°. The milk in the tank is now ready to be filled into the cans. It is important to know that the filling of the milk should not be started until all of the tests upon the Controller have been completed. How to Add Sodium Bicarbonate to Milk Before Sterilizing. — In case that it is necessary to add sodium bicarbonate as might have been done in the preeeeding problem, this should be done as follows : The amount to be added is to be determined entirely by the viscosity tests of the milk upon the five sample cans. In the above example it was noted that can No. 2 showed a viscosity of 150° retardation. Since this is the standard of viscosity that it is desired to reach, bicarbonate should be added in the amounts indicated, being in the case of the milk under question, 2 ounces per each one thousand pounds of vaporated milk on hand. Since the batch contained 24,000 pounds, it will now be necessary to weigh out 48 ounces of the solid bicarbonate upon the Torsion Balance. This is then dvimped into a ten gallon milk can, a small amount of water, with a little evaporated milk, usually just the sample cans, is then added to the bicarbonate in the can. The entire mixture is brought to a vigorous boil, by means of the steam hose attached to the Controller. The boiling should be continued until the gas has been fairly well expelled. This will not eliminate all the gas which is contained in the bicarbonate, but it will eliminate the greater part of it, since sodium bicarbon- ate is not a stable compound, and is partly broken up by heat under these conditions. The solution may now be added to the evaporated milk in the holding tank. The milk should be agitated while the bicarbonate solution is being added, and the bicarbon- ate solution should be poured in very slowly. As the amount used is usually small, it is not necessary to cool it back before adding it to the milk, as the amount is not sufficiently large to increase the temperature of the milk in the hold-over tank. It is very important to allow the agitators to run for from ten to twenty minutes before starting the fillers. The time neces- 748 Evaporated Milk sary here depeuds upon the efficiency of the agitators, and it can be determined accurately oul}^ by careful experiment. How to Adjust the Sterilizing Records Upon Different Sizes of Cans. — Different sizes of cans require difit'erent sterilizing tem- peratures to produce the same viscosity. Tall size cans require 1° more heat upon a 15 minutes' run that does baby size. For example, upon the same batch of milk, the record would be 240° F. for 15 minutes for baby size, and 241' F. for 15 minutes upon tall size. How to Change the Temperature of Heating the Milk in the Hot Wells. — The method of changing the temperature necessary to heat the milk in the hot wells is indicated by the following example : Sample can marked X cools 70° retardation. Sample can marked 1 cools 40' retardation. Sample can marked 2 cools 30° retardation. Sample can marked 3 cools 20° retardation. Sample can marked 4 cools 15° retardation. As the results indicate, the blank can marked X which con- tains no bicarbonate shows viscosity under the standard desired, namely 150° retardation. This is short in viscosity to the extent of 80° retardation, which is equal to 4° F. upon the temperature to which the milk is heated in the hot wells under 212° F. upon the above mentioned correlated values. Granting that the milk has been brought to a temperature of 212° in the hot wells, it develops from the results of the viscosity tests that the milk in this batch had been forewarmed 4° more than should have been the case, that is, it should have been forewarmed at 208° F. Assuming that the milk in this particular case is now all in" the tank, it is, of course, impossible to go back to correct the forewarming of the milk in the hot wells. All that can be done is to increase the sterilizing temperature from 243 to 245° F. at the standard holding time of fifteen minutes. Tt is always recommended that a preliminary test be made of the milk before the condensing is all completed. In the above problem, it is recommended that the foroAvarmhig of the milk of the succeeding day be modified upon tln^ basis of results obtained Avith the batch in question, that is, granting that climatic con- ditions and the general milk supply remain the same. In that b'TERiiwizATioN Control 749 case, it is sugge.^tecl that with a plant having four batches of raw milk, each containing about twelve thousand pounds, that im- mediately after three of the batches are condensed and cooled, and well mixed together in the hold-over tank, that a preliminary sample of these batches be run. If it is found that the milk from these three batches is of too low viscosity, the last batch can be forewarmed at a sufficiently low temperature to increase the viscosity of the three preceding batches to the desired point. It is possible to condense the milk at as low a forewarming tempera- ture as 140° F. However, when this is done, care must be taken to see that a good sterilizing record is used, as otherwise there may be danger of spoilage of the milk. It is not recommended that the milk taken for these pre- liminary tests be standardized for fat and total solids. If the tests of the milk at the strike is carefully watched, the product will be near enough to chemical standard so as not to affect greatly the physical properties. If this plan is followed,, plenty of time is available to make the tests upon the Controller before the forewarming of the last batch is completed for the day. If necessary, the last batch can always be held up for a little while in order to complete this test, and it is recommended that this be done rather than sacrifice on the physical properties of the finished product. Why Evaporated Milk Sometimes Fails to React with Sodium Bicarbonate. — Conditions are very frequently encountered in evaporated milk plants under which it is impossible to improve the quality of the product by adding bicarbonate of soda. This is illustrated by the following set of viscosity tests made upon one batch of milk that was standardized to exactly 25.50 per cent total solids. TABLE 142. Evaporated Milk That Failed to React to Bicarbonate of Soda. Ounces sodium bicarbonate added per thousand pounds evaporated milk. Viscosity after sterilizing 240° F. for fifteen minutes. o 4 6 10 112° retardation 180° retardation 280° retardation 280° retardation Too heavy to get viscosity. 750 Evaporated Milk As the above results indicate, the addition of the bicarbonate had just exactly the opposite effect to that vs^hen added to milk that was handled in the way that was recommended above. That instead of reducing the viscosity of the milk it increased the viscosity. This plainly indicated that the milk had undergone chemical changes in the casein molecule. The factors that will bring about the above mentioned conditions are as follows : (1). Improper forewarming of tlie milk in the hot wells. This point has already been mentioned. (2). Homogenizing the milk at too high a pressure. The trouble that may result from this cause can be determined experi- mentally under the conditions which exist at each particular plant. It is seldom desirable to homogenize the milk much above 2,000 pounds pressure, (3). Handling of the milk by the so-called "wash process," Under this process the milk is condensed to about %. its original volume. It is then cooled, and an amount of water added slightly in excess of that required to bring the milk back to the desired consistency, and finally recondensing the surplus of water added to the milk. This is a wasteful process, which exerts a very bad effect upon the milk, (4). Brine leaks from the cooling coils at the condensed milk cooler. This is a frequent cause of trouble. If care is taken in the plant, all of the above conditions that tend to change the chemical composition of the milk can be avoided, thereby making it psssible for the milk to react to sodium bicarbonate in a perfectly normal way. How to Reduce the Amount of Bicarbonate Necessary to Add. — It is always very desirable to keep the amount of bicarbon- ate down to the very lowest minimum. The indiscriminate use of this product may lead to several serious consequences. In the first place, the gas from the bicarbonate is released during the sterilizing process, and this will cause the ends of the can to bulge. If an excess is used, it becomes impossible to again press the ends back into normal position, so that they may be bulged when sent to the consumers. In the second place, an excess of bicarbonate is bound to increase greatly the color of the milk, making the milk much darker than it would be normally. Sterilization Control 751 The following steps can be taken to reduce the use of bicar- bonate. Observation that the proper methods of handling the milk are practiced upon the dairy farms. It is particularly necessary to have the milk well cooled and kept in well cleaned cans. Also, that all utensils in which the milk is handled are kept clean and sterile at all times. Colostrum milk should be rejected. Changes in the chemical composition of the milk are responsible more than anything else for the use of bicarbonate. In localities where summer dairying predominates, the change in the composi- tion will become apparent more in the fall of the year. Upon the other hand, where winter dairying predominates, the same trouble may be encountered at other seasons. The trouble is, however, very much more prevalent in the fall of the year and during the winter months than during all of the other seasons (iombiued. It is possible that the fact that the cows are being placed upon dry feed exerts some influence upon this condition. This is by far tlie most important of all conditions which compel the use of bicarbonate. No means are known to science at the present time whereby these conditions can be successfully over- come except by means of sodium bicarbonate. Milk that is too long in transit to the factory is likely to develop an excess of acid, and may, therefore, require bicarbonate. Milk that is held in storage at the factory at too high tempera- tures, or for too long a time before it is heated in the hot wells, also develops excessive acid. This is a very frequent cause of trouble, and frequently such milk is changed too much to make it possible to handle it at all. Improper cooling of the milk after it leaves the vacuum pan, and holding the milk in the storage tanks too long before it goes to the fillers are all contributing causes. Unsanitary methods in the plant itself, that is, improper cl6aning of the vacuum pan, or of the hot wells, or homogenizer, or storage tanks, or filling machines, can all become contributing causes to this trouble. The handling of two days' milk, sometimes practiced over the winter months, is also responsible for a great deal of trouble along these lines. Tlu're are very few dairies tliat are equipped to hold milk over in good condition for two days. The milk, therefore, is exposed to all kinds of unfavorable conditions and this, of course, affects the quality of the finished product. 752 EVAPORATHID MiLK SEASONAL VARIATIONS IN THE COAGULATING POINT OF EVAPORATED MILK. The seasons do not in themselves directly intiiienee the co- agulating point of evaporated milk, but indirectly they are a large factor, and year after year changes in the coagulating point fol- low closely the changing seasons. Paralleling the changing seasons, and probably the direct causes of the variations in the coagulating points can be mentioned : (1). The changes in the milk due to the lactation period. — If the coAvs supplying a given plant, always freshen at about the same time of the year, then more marked will be the influence of the lactation period. These differences can be considerably equalized by arranging for the cows to freshen at dift'erent months, thus making possible, both summer and winter dairying, which is an added advantage in plant operation. (2). Variations caused by changes in the feed of the cows. — Particular reference is made here to the influence of such changes upon the components of the milk as affect the coagulating point. Relatively little exact information is now available upon this subject. It is well known that as soon as cows change from dry to green feed, or vice versa, that a change in the coagulating point of the milk is at once apparent. (3). Variations caused by temperature and other climatic changes. — It is well known that immediately following storms, the coagulating point of the milk usually decreases several de- grees. This has reference to the mixed milk from a large number of herds. Part of this decrease may be caused by the increased acidity which is usually produced because of the conditions fav- orable to acid development that exist at the time of a storm. Changes in the temperature itself surrounding the cow, aside from other factors, may cause changes in the composition of the milk, such as would influeiiee its heat coagulation, but as yet relatively little is known upon this subject. Fig. 171 illustrates the average of several seasonal variations ill the coagulating point of evaporated milk. This refers to evaporated milk produced at plants located in the temperate zone, where, both summer and winter dairying are practiced. It is assuuicd that the eoagnlating points indicated would be those Variation in Coagulating Point 753 obtained by foreAvarming the milk all alike in the hot wells ; con- densing it to the Federal standard of butter fat and total solids ; sterilizing it for 15 minutes at the various temperatures indicated, and in all cases obtaining a viscosity of 150° retardation. Under 2lM 2 Tight, sound floor and proper Clean i , gutter 2 Well drained . .' i Smooth, tight walls and ceil- ing I Removal of manure daily .... Proper stall, tie, and manger . i To 50 feet or more from stable. of glass per cow 4 MILK ROOM on, MILK HOUSE (Three sq. ft., 3 • s sq. ft.. 2 ; i Cleanliness of milk room .... .sq. ft., I. Deduct for uneven dis- tribution.) UTENSILS AND MILKING I Care and cleanliness of utensils . 8 Ventilation Provision for fresh air, control- Thoroughly washed . . . . 2 lable flue system 3 (Windows hinged at bodom. Sterilized in steam for 15 ( Placed over steam jet or scald- openings .50). ed with boiling water, 2.) Cubic feet«of space per cow, Protected from contamination . 3 500 feet 3 Cleanliness of milking 9 (l,e.ss than 500 ft., 2 ; less than 400 ft., 1 ; less than 300 ft , 0). Clean, dry hands 3 ■ Provision for controlling tem- Udders washed and wiped . .6 (Udders cleaned with moist cloth, 4; cleaned with dry cloth UTENSILS or brush at least 15 minutes be- fore milking, i.) Construction and condition of HANDLING THE MILK Water (or cleaning ant.) Small-top milking pail ....... room 2 5 Milk removed immediately from stable without poiiring Jrom pail 2 1 Cooled immediately after milk- Clean milking suits I 2 5 MILK ROOM, OR MILK HOUSE Cooled below 50° F (5'° to 55°, 4 ; 56° to 60°, 2.) Location free from contamiiut- Stored below 50° F (51° to 55°, 2 f 56° to 60°, I.) 3 1 Construction of milk room . . . Floor, walls and ceiling . . . ,1 Light, ventilation, screetfs . . i Separate rooms for washing Transportation below 50° F. . . (5>° to 55°. 1-50 ; 56° to 60°, I.) 2 utensils and handling milk . . I (If delivered twice a day atlow Facilities for steam (Hot wa» lero.5) I perfect score for storage and transportation.) Total . . . . . . 40 60 Equipment + Methods. -Final Score Note i— If any exceptionally filthy condition is found, particularly dirty utensils, the total score may be further limited. Note 2— If the water is exposed to dangerous contamination, or there is evidence of the presence of a dangerous disease in animals or attendants, the score shall be o. 7J^ Score Cards ITHACA BOARD OF HEALTH SANITARY INSPECTION OF DAIRY FARMS MARKET MILK PRODUCTION SCORE CARD Indorsed by the Official Dairy Instructors' Association. Owner or lessee of farm P. 0. address State Total number of cows Number milking Gallons of milk produced daily Product is sold by producer to families, hotels, restaurants, stores, to dealer For milk supply of Permit No Date of inspection 192 Remarks: (Signed) Inspector Dairy Farms 779 !^ ce o be *^ C .. § d > ° (H o S X! SCfl O -tJis CO o *-i >-" o ■ -a ^ N '5 c' : o o m rrt si ■o ■W nj CO to S .-« 4) o c2 -a * he (U p O-^J o oi a> ^ C P •- rf CO " 3 fe- rn ^ U H c £ o O 5o H "o a He ci ^ cd u 5 U W h Q|i.i to BJ T^F fin O o tfl ■^ c .. Sd > - ^S 53 O r- k ^< a O *J " " » O 3 c >i Ih t* ^ 3 o S - Of: t, o M S- Co ■I::; - 3 IS w o 2 o ^ g •- ^ 3 C s5 <^ <; ^ C C ?i ,^ t^ ^ M 03 01 . '-' 2 V% 3 . S I) 'Cm* ^.2 '' '^ 43.ti 2 - L, 22So S (h - 01 _ 1-1 Si-' 43 •H o r, o£o5 ^ •w 03 03 " ■« — CO)" c 3 ^i; o + 780 ScoRR Cards VETERINARIAN'S SCORE Date Producer Phone.. Address Total number Cows Number Milking Number not Milking Cause.. Number Tuberculin Tested Date General Conditions Coat Flesh Attitude. Respiratory System — Cough Respiration Percussion Auscultation .'. Lymphatic System Udder Animal has symptoms suspicious of. Remarks Rating of Herd — E.xcellent, Good, Fair, Poor. Signed Veterinarian. Milk Plants 781 UNITED STATES DEPARTMENT OF AGRICULTURE BUREAU OF ANIMAL INDUSTRY DAIRY DIVISION SANITARY INSPECTION OF CITY MILK PLANTS SCORE CARD Owner or manager Street and No. , City State. Trade name Number of wagons Gallons sold daily Permit or License No. Milk Cream. Date of inspection '. , 192. Remarks: ; , Inspector. D. D. 331.— 10-8-15 — 5,000. 8—2475 [OVER] 782 Score Cards EQUIPMENT Building: Location: Free from contaminating surroundings .■ Arrangement Separate receiving room 1 Separate handling room 2 Separate wash room 1 Separate sales room 1 Separate boiler room 1 Separate refrigerator room 1 Construction Floors tight, sound, cleanable. . . 2 Walls tight, smooth, cleanable... 1 CeUingssmooth, tight, cleanable. 1 Drainage 2 Floors 1 Sewer or septic tank 1 Provision for Ught 2 (10 per cent of floor space.) Provision for pure air 2 Screens 1 Minimum of shafting, pulleys, hangers, exposed pipes, etc 1 Apparatus BoUer 2 (Water heater, 1.) Appliances for cleansing utensils and bottles 2 Sterilizers for bottles, etc 2 Bottling machine 1 Capping machine 1 Wash bowl, soap, and towel in handling room 1 Condition — .-6 Milk-handling machinery 3 Pipes, couplings, and pumps. . 2 Cans 1 Labobatory and equipment Per- fect. Water supply , Clean and fresh 1 Convenient and abundant 1 Total. Al- lowed. B UILDING Cleanliness: Floors 3 Walls 2 Ceilings 2 Doors and windows 1 Shafting, pulleys, pipes, etc 1 Freedom from odors 2 Freedom from flies 3 Apparatus Cleanliness: Thoroughly washed and rinsed.. 3 Milk-handling machinery ... 2 Pipes, cans, etc 1 SteriUzed with live steam 3 Milk-handling machinery .. . 2 Pijies, cans, etc 1 Protected from contamination. . . 1 Bottles Thoroughly washed and rinsed — 3 SteriUzed with steam 15 minutes. . 3 Inverted in clean place 1 Handling mtt.k Eeceived below 50° F 3 (SO" to 55°, 2.) (55° to 60°, '1.) Rapidity of handling 2 Freedom from undue exposure to air 2 Cooling 5 Promptness 2 Below 45°F.. 3 (45° to 50°, 1.) Capping bot ties by machine 2 Bottle top protected by cover — .1 Storage; below 45° F 4 (45° to 50°, 3; 50° to 55°, 1.) Protection during delivery „.. 2 (Iced in summer.) Bottle caps sterilized 1 Inspection Bacteriological work 3 Insi)ection of dairies supplying milk 3 (2 times a year, 2; once a year, 1.) Miscellaneous Cleanliness of attendants 2 (Personal cleanliness, 1; clean, washable clothing, 1.) Cleanliness of deUvery outfit 2 SCORE. Per- fect. Total. Al- lowed. Score lor equipment.— plus score for methods equals Total Score jjoTE If the conditions in any particular are so exceptionally bad ^s to be inadequately expressed by a score of •>0" the inspector can make a deduction from the total score. ft— 2475 Stores 783 .2 PM •-M '■■ c PQ 'o HH CO B H-t o _5 Q =* °W 3 c« CO 3« mo 3 , 30 ■=& bJDO -^^^ .^^ o CC l-H ■8 i ! > < 1 1 fOCI M(M S M u^ 2lM-H 0) .. c •35 4h MX! O ty 03.5 C « 3 <= 2 a -•-2c 12 O oj tJJrrt ii O tT JST! « t. b - fc. feO 3 ■2^ o „ X!° ^C 5"= 5 - o;s do "O c «"= SiJ oe « * 0) >H < £» 15 a. • 0) c ^ •■-; C ~ dJ^ O c ?5 ce ., rt c 0) « ot o o O O fi o ^3 03 •51-] m 3 -^ « . m, e: of - to p ?^ 1 *j r; w c o " ( M o S •" 43 'S I 3 O^BJ-T^W Sf glODq MMTHgN jj 01*' o 3 to c 0) CQ 3 -3-2.5 2 3 o tSt-* -5 r'-'S O O .^o§S ^ H^Oo 784 Score Cards THE SCORE CARD FOR DAIRY PRODUCTS. The score card for dairy products aims to give an orderly arrangement of the points which a good product possesses. It places a numerical value on each point and allows space for re- cording the grade assigned in scoring each point. There is also provided space for the name and address of the producer or ex- hibitor, necessary dates, name of inspector or judge and remarks. The advantages of a good score card are (1) its educational feature, (2) its influence toward improving quality, (3) it is an orderly record that may be filed for reference, (4) it tendR to eliminate error. In marketing and manufacturing, the score of a product in it self is usually of prime importance since it is a large factor in fixing the market or price value. The score card here serves as a record that gives in mathematical terms the credits allowed on each factor that influences value. This record may be of con- siderable importance when studied for the purpose of improving quality, when used as a basis for trading, and in settling disputes as to quality. The sanitary quality of milk is the most important factor affecting its value, as milk cannot be used as a food if it con- tains pathogenic organisms or filth. Its chemical composition comes next in importance as it governs the nutrient value. Taste and odor come next in order, with color, appearance and other details last. The following score card illustrates the arrange- ment of points and method of assigning credits for retail bottled milk. Certified milk: The scoring of certified milk is carried out in essentially the same manner as in the case of market milk, but the bacteria count is limited to a narrower range and credits as- signed accordingly. Also any special guarantees in regard to composition must be recognized and the container should comply with the regulations for certified milk. Milk 785 UNITED STATES DEPARTMENT OF AGRICULTURE, BUREAU OF ANIMAL INDUSTRY, DAIRY DIVISION. sc Plar.p. ORE CARD FOR MILK. Class 1 Ixhihit J^o ITEM. Perfect SCORE. Score ALLOWED Remarks. Bacteria 35 15 10 15 15 5 5 Bacteria found perl cubic centimeterj Co\vy, bitter, feed,l flat, strong j' " Flavor and odor Sediment Fat. Per cent Solids not fat Per cent Temperature (street samples) . ("Degrees or < or Acidity (prepared sam- Per cent Bottle and cap fBottle- _.. -.- Total - 100 [cap. Exhibitor ..... Address — {Signed) Jiidges. Date - -— 786 ScoRii Cards DIRECTIONS FOR SCORINc. BACTERIA PER CUBIC CENTIMETER— PERFECT SCORE, 35. PorNTS. i 500 and under... 35 501-1,000- 34.9 1,001- 1,500 34.8 1,501- 2,000 34.7 2,001- 2,500 34.6 2,501- 3,600 34.5 3,001- 3,500 34.4 3,501- 4,000 34.3 4,001- 4,500 34.2 4,501- 6,000 34.0 5,001- 6,000 33.8 6,001- 7,000 33.6 7,001- 8,000 33.4 8,001- 9,000 33.2 9,001-10,000 33.0 10,001-11,000 32.8 11,001-12,000 32.6 12,001-13,000 32.4 13,001-14,000 32.2 14,001-15,000 32.0 15,001-20,000 31.0 20,001-25,000 30 Points. 25,001- 30,000 29 50,001- 35,000 28 35,001- 40,000 - 27 40,001- 45,000 26 45,001- 50,000 25 50,00r- 55,000 24 55,001- 60,000 23 60,001- 65,000 22 65,001- 70,000— 21 70,001- 75,000 20 75,001- 80,000 - 19 80,001- 85,000 18 85,001- 90,000 17 90,001- 95,000 16 95,001-100,000 15 100,001-120,000 12.5 120,001-140,000 10.0 140,001-160,000 7.5 160,001-180,000 _... 5.0 180,001-200,000 2.6 Above 200,000 beO. Note. — When the number of bacteria per cubic centimeter exceeds the local legal limit the score shall FLAVOR AND ODOR— PERFECT SCORE, 16. Deductions for disagreeable or foreign odor or flavor should be made according to conditions found. When possible to recognize the cause, it should be described under " Eemarks." SEDIMENT— PERFECT SCORE. 10. Jlxamlnation for sediment may be made by means of a sediment tester, and the resulting cotton disks compared with standards; or the sediment may be determined by examination of the bottom of the milk in the bottle. In the latter case the milk should stand undisturbed for at least an hovu before the examina- tion. Raise the bottle carefully in its natural upright position imtil higher than the head. Tip slightly and observe tho bottom of the milk with the naked eye or by the aid of a reading glass. The presence of the slightest movable speck makes a perfect score impossible. Further deductions should be made according to tho miantity of sediment found. When possible, the nature of the sediment should be described imder "Remarks." FAT IN MILK— PERFECT SCORE. 15. Points. 4.0 per cent and over 15 3. 9 per cent 14 3. 8 per cent 13 3. 7 per cent 12 3. 6 per cent 11 3. 5 per cent 10 3.4 percent 9 Points. 3.3 percent 8 3. 2 per cent 7 3. 1 percent 5 3.0 per cent 3 2. 9 per cent 1 Less than 2.9 per cent Note.— When the per cent of fat is less than the local legal limit the score shall be SOLIDS NOT FAT— PERFECT SCORE, 15. Points. 8. 7 per cent and over 15 8. 6 per cent 13 8. 5 per cent 11 8. 4 per cent... 9 8.3 percent 7 Points. 8. 2 per cent 5 8.1 percent 3 8 percent 1 Less than 8 per cent HoTE. — When the per cent of sohds not fat is less than the local legal limit the score shall be 0. TEMPERATURE (STREET SAMPLES)— PERFECT SCORE, 5. Points. SOdegrees F. and below 5 51 to 53 degrees 4 64 to 66 degrees 3 Points. 57 to 60 degrees 1 Above 60 degrees -- ACIDITY (PREPARED SAMPLES)— PERFECT SCORE. 6 Points. 0. 2 per cent and less.. - 5 0.21 percent . 4 0.22 per cent. .„ _. 3 Points. 0.23 percent 2 0.24 percent 1 OverO.24 percent BOTTLE AND CAP— PERFECT SCORE, 5. Deductions in score should be made for dirty or chipped bottles; for caps which do not cover the lips ■ of the bottles, or do not fit properly in the cap seats. ' — <^ {Bacteria 85 Flavor aiid odor 25 Patg .^.10 Solids not fat...., 10 Acidity"' " Bottle and cap 5 Skim-Milk ^87 Skim-milk. The scoring of skim-milk has heretofore received very little consideration. The greater value now placed upon skim-milk as a food and the larger application of skim-milk prod- . ucts as a food and in the arts, makes it very desirable to have a score card that gives in a systematic way the respective points that good skim-milk should possess and provide space for record- ing the necessary data relating to samples scored. The score card need not differ in principle from that used for whole milk but the credits allowed for the different points may vary somewhat in proportion to their influence upon the value of the skim-milk in the use that is to be made of it. The ex- planation of scores given for whole milk may be applied also for skim-milk. Owner . Address Class ... SCORE CARD FOR SKIM-MILK. Date Exhibit No. Item Score Remarks : Perfect Allowed Bacteria 35 Flavor and odor 20 Sediment 10 Solids not fat 15 Temperature (street sample . 5 Acidity 5 Fat 5 Container 5 Total 100 Date scored. Judges I Score Cards UNITED STATES DEPARTMENT OF AGRICULTURE, BUREAU OF ANIMAL INDUSTRY, DAIRY DIVISION. SCORE CARD FOR CREAM. Place Class Exhibit JVb. ITEM. Bacteria Flavor and odor Sediment Fat. Temperature (street samples) -- or Acidity (prepared sam- ples). — Bottle and cap Total ... Perfect SCORE. 35 25 10 20 100 Exhibitor. Address .... {Signed) Score ALLOWED. Beuabks. Bacteria found per"! cubic centimeter/ ■ Cowy, bitter, feed,"! flat, strong j' Per cent. or Per cent. [Bottle. [Cap .... Date. Judges. Cream directions for scoring. 789 BACTERIA PER CUBIC CENTIMETER— PERFECT SCORE. 35. 500 and under - I 501-, 1,000 \ 1,001- 1,500 . I 1,501- 2,000 i 2,001- 2,500 i 2,501- 3,000 ; 3,001- 3,500- - i 3,501- 4,000 i 4,001- 4,500 c 4,501- 5,000 c 5,001- 6,000 ; 6,001- 7,000 ; 7,001- 8,000 ; 8,001- 9,000 ! 9,001-10,000 : 10,001-11,000 : 11,001-12,000 ; 12,001-13,000 ! 13,001-14,000 ! 14,001-15,000 ; 15,001-20.000 ! 20,001-25,000 ! Note. — When the number of bacteria per shall be 0. Points. 25,001- 30,000 29 30,001- 35,000 28 35,001- 40,000 ,. 27 40,001- 45,00a. - 26 45,001- 60,000 25 50,001- 55,000..., 24 55,001- 60,000 23 60,001- 65,000.... 22 65,001- 70,000 21 70,001- 75,000 20 75,001-80,000. 19 80,001- 85,000 18 85,001- 90,000. w 17 90,001- 95,000 16 95,001-100,000... 15 100,001-120,000 12.5 120,001-140,000 10.0 140,001-160,000 7.5 160,001-180,000. 6.0 180,001-200,000. 2.6 Above 200,000 centimeter exceeds the local legal limit the score FLAVOR AND ODOR— PERFECT SCORE. 25. Deductions for disagreeable or foreign odor or flavor should be made according to conditions tound. When possible to recognize the cause of the difficulty it should be described under " Remarks." SEDIMENT— PERFECT SCORE, 10. Examination for sediment should be made only after the cream has stood for at least an hour undis- turbed in any way. Raise the bottle carefully in its natural upright position until higher than the head. Tip slightly and observe the bottom of thf cream with the naked eye or by the aid of a reading glass. The presence of the slightest movable speck makes a perfect score impossible. Further deduc- tions should be made according to the quantity o{ sediment found. When possible the nature of the sediment should be described under "Remarks." FAT IN CREAM— PERFECT SCORE. 20. Points. 25 per cent and above 20 24 percent 19.5 23 per cent 19 22 per cent 18.5 21 percent 18 20 per cent . 17.5 Points. 19 per cent 17 18 percent 18 17 percent 12 16 percent 8 15 percent 4 Less than 15 per cent Note.— ^Vhen the per cent of fat is less than the local legal limit the score shall be 0. TEMPERATURE (STREET SAMPLES)— PERFECT SCORE. 5. Points. 50 degrees F. and below 5 51 to 53 degrees 4 54 to 56 degrees .- 3 Points. 57 to 60 degrees. , 1 Above 60 degrees * ACIDITY (PREPARED SAMPLES)— PERFECT SCORE. 6. Points 0. 2 per cent and less 6 0.21 percent — 4 0.22 per cent.. 3 POINTS. 0.23 percent.. 2 0.24 percent 1 Over 0.24 per cent BOTTLE AND CAP— P6RFECT SCORE, 6. Deductions in score should be made for dirty or chlnped bottles; for caps which do not oover theUps ,of the twttles, or do not fit properly In the cap seats. 790 Score Cards Cream: The method of scoring cream is essentially the same as that applied in scoring milk. It is not ordinarily scored for solids not fat. Whether it should receive such a score or not, is a debatable question. Where the minimum percentage of fat in cream is fixed by legislative or similar enactments, full credit may be allowed if the composition conforms to such fat standard. It is customary, however, to require the presence of at least 20 per cent of fat in cream in order to be entitled to the full score. SCORE CARD FOR BUTTER. The systematic scoring of butter is carried out in commercial transactions between producers and dealers and between the deal- ers themselves. It is also practical in scoring butter at butter exhibitions and in giving instruction in dairy schools. The prac- tice does not extend to an}^ great extent to the commercial trans- actions taking place between the ultimate retailer and consumer. As the practice of scoring butter has continued over a long period of years, the system has become fairly well fixed, and the factors that affect quality satisfactorily established. Butter score cards may vary somewhat in form according to the use that is to be made of the score. In general they include the factors and take the general form of the card shown here as an example. Flavor: This is the most important factor in fixing the score, and perfect flavor is rarely if ever given. Body: The ideal butter is firm, hard and waxy which prop- erties prevent it from softening or melting too easily. Poor body is described as weak, greasy, leaky, short-grained and sticky. The "body" of butter is not of such importance to the consumer as that of flavor, and recent methods of manufacture have not contributed toward improving it. Color : The shade of yellow color in butter varies in different markets. All require that it be uniform, that is, free from streaks, mottles, waves and specks. Where there is too much color it is said to be too high and where the yellow is too pale the color is said to be too light. Salt: The percentage of salt also varies according to the demands of the trade, which in turn, is governed by the likes and dislikes of the consumer. If the salt is not all in solution or is not evenly distributed the score is reduced. Butter 791 Package: The package is controlled by market requirements. In any case it must be substantial, attractive, neat and clean. The interior wrapper should be free from wrinkles, properly fold- ed and the workmanship good throughout. (3wner . Address Class ... SCORE CARD FOR BUTTER. Date E.xhibit No. Quality factors Perfect score Score Allowed Remarks : Flavor 45 Body 25 Color 15 Salt 10 Package 5 Total 100 Fat Moisture Salt . . . Casein . . per cent . per cent .per cent . per cent Date scored. f Judges \ [ Butter is graded on the market according to the score it re- ceives. The grade given by the New York Mercantile Exchange cor- responds with the score as follows : Grade : Higher scoring Extras Firsts Seconds Thirds Score: 93 or above 92 91 to 88 87 to 83 82 to 76 Other classifications sometimes are "Packing stock", "ren- ovated", and to butter of inferior quality "cooking butter", "ladels" and "grease". While different judges may check closely on the score, butter that satisfies the best trade in one market may not do so in another, thus the same butter might receive a different score and grade on two different markets, like, for example, Boston and New York. Also, when the supply is short and demand strong, butter that would ordinarily go into one grade may be raised a grade higher, and when the opposite conditions prevail it might be dropped a grade lower. This practice is confusing until trade customs are learned. 792 Score; Cards Flavor: It consists of those properties that affect the senses of taste and smell. Nearly ever}^ one can become proficient in judging butter by intelligently using the senses of sight, taste and smell, although such physical tests are very difficult to describe. A number of terms are used in describing flavor as it varies widely and is due to many causes. Those tastes or odors which are pleasing and which develop in one an appetite or desire to eat more of the butter receive credit while those that have the opposite effect reduce the score. Such terms as clean, creamy, pleasant, delicate, and sweet are favorable, while the following are unfavorable : cowey, barney, old, strong, tallowy, rancid, fishy, fruity, and weedy. CULTURE SCORE CARD. Culture or starter, as the term applies in dairying, is an active culture of bacteria that are used for the purpose of developing lactic acid fermentation in milk and milk derivatives. It finds its greatest application in the manufacture of butter, cheese and milk beverages. Quality in starter is of first impor- tance as it transmits its properties to the material to which it is added and when the quality is poor it may be the cause of con- siderable loss. The factors that contribute to quality in a good culture are not unlike those for buttermilk. The score cards proposed usual- ly follow the same general outline. The one used by the Dairy Department of the N. Y. State College of Agriculture at Cornell University will serve as an example : CORNELL CULTURE SCORE CARD. Score Perfect Allowed Flavor 50 20 20 10 Aroma Clean, agreeable acid. No undesirable aroma. 0.6 per cent — 0.8 per cent. Before breaking up: Jelly Acidity Body Total 100 like, close, absence of gas holes. No free whey. After breaking up: smooth, creamy, free from gran- ules or flakes. I Buttermilk 793 THE BUTTERMILK SCORE CARD. The value of good buttermilk as a food and healthful stimu- lating beverage is generally acknowledged but in the past methods for regularly producing the desired flavors and aroma were lack- ing. Recent improvement in methods of handling milk combined with a better understanding of the principles that control fer- mentation is rapidly overcoming these difficulties and it is now possible by the use of proper methods and improved equipment to regularly produce buttermilk of high quality having the same desirable properties from day to day. There is need for a better general knowledge of the factors that produce quality in buttermilk since quality must be depend- ed upon to increase the demand. The use of a score card will be a help in gaining this desirable end in the same way that it has been of so much service in improving the quality of market milk. The following score card may be adapted to the purpose : BUTTERMILK SCORE CARD. Owner .. Address Class .... Date Exhibit No. Quality Score Remarks : factor Perfect Allowed Flavor 45 Clean, delicate, pleasant, de- Aroma 15 sirable acid. Clean, agreeable, attractive, Body 15 delicate, mild. Smooth, even, jelly-like, close, creamy. 0.7 per cent to 0.9 per cent. Clean, neat, substantial, non- corrosive. Oderless. Acid 15 Container 10 Total 100 Date scored. Judges 794 Score Cards CHEESE SCORE CARDS. The quality of cheese is affected by (1) the quality of the milk that enters into it, (2) the method applied in its manufacture and (3) by the fermentation that takes place during the making process, curing and storage. The defects may be many and varied and it requires practice, study and experience to become skilled in detecting them, and especially to assign proper credits to the points of merit which will correctly indicate commercial value. The properties that have been adopted as a basis for scoring cheddar cheese are (1) flavor, (2) body and texture, (3) color and (4) finish. The flavor of high qualitj^ cheese is very characteristic yet so unlike other substances that it is difficult to describe. It is slight- ly salty, mingling the flavor of fat with acid and protein sub- stances in a way that yield a very attractive rich flavor some- times described as mildly nutty. Unpleasant and offensive odors and tastes should be absent. Flavors: Volatile substances from the feed of the cows pro- ducing milk are sometimes transmitted to the cheese. They are known as weedy or feedy flavors. They vary according to the flavor of feed. "Cowey" flavor remind one of the odor of the breath of a cow. Sweet flavors characteristic of some of the common fruits are described as fruity. They may be derived from fermentations caused by organisms found in decomposing milk substance and indicate that the milk from which the cheese was made came in contact with unsanitary conditions. Cheese that has a pronounced sour smell or taste is described as acid. It is due to the presence of an excess of acid. Flat flavor indicates an absence or reduction in the flavors present in high quality cheese. Other terms are bitter, rancid, tallowy and mouldy. Texture and Body: When the texture of the cheese is good there should be no holes and the broken ends of a plug should appear close, solid, compact and well annealed, yet flakey and somewhat like broken flint. When pressed and rubbed between the thumb and finger it should feel smooth, silky and waxy. Body refers to the firmness or consistency of the substance. It is judged at the same time and in the same manner as the texture. When the body is good it will feel somewhat firm under pres- sure, but not too firm, and when pressure is applied it should not Chuese 795 break or crumble but yield in form like cold butter. It should not feel harsh or gritty nor soft and pasty. Stiff, corky, curdy, weak-bodied, salvy, and watery are self explanatory terms used in describing cheese body. . Color: Color is ordinarily considered perfect if it is uniform. The depth of the shade of yellow is not important as long as it satisfies the demands of the market in which it is sold. The fancy or whim of different markets vary in respect to the shade of 3^ellow color. Finish: Finish is important as it is likely to be taken as an index of the workmanship put into the manufacturing process which in turn has so much to do with quality in cheese. Finish may or may not include the package or box — but a dirty, dilapi- dated and untidy container should never be used. The surface of the cheese should be clean, smooth and free from cracks. The edges should be even and the bandages neaitly arranged, giving an impression of value and quality. Owner . Address SCORE CARD FOR CHEDDAR CHEESE. Date Exhibit No., Item Score Remarks Perfect Allowed Flavor 45 Body and texture 30 Color 15 Finish 10 , Total 100 Date scored. Judges SCORE CARD FOR COTTAGE CHEESE. Cottage cheese is one of our most wholesome food products. With the large surplus of milk solids not fat always available its use should greatly increase. Good quality will do much to stimulate consumption. The authors are suggesting the follow- ing score card in grading this product. 796 Owner . Address Score Cards score card for cottage cheese. Date Item Score 66 Remarks: Perfect Flavor 50 Mild, clean, acid flavor. Viscosity and texture 20 Body or viscosity fairly firm. Smooth to the taste. Color 5 Creamy cast. A little odor enhances its commercial value. Appear ance of package 5 .--._ Neat, clean with every evi- dence of careful work- manship. Composition .... 20 Sufficient total solids to give good food value to the product. Total 100 Date scored. Judges SWISS CHEESE. In scoring Swiss Cheese special attention is given to its typical nutty flavor and slightly sweet, pleasing taste. Off flavors, de- rived from the milk or undesirable fermentation, should be wholly absent. The characteristic ''eyes" or holes should be rather evenly distributed from one to three inches apart. They are normall.y from one-half to three fourths of an inch in diam- eter. The substance between the eyes should be compact, and free from small holes which indicate that undesirable gas pro- ducing fermentation has occurred. The salt should have passed well through the cheese. The body should be firm and the rind smooth, clean and free from cracks. Owner . Address Class ... Cheese score card for swiss cheese. Date Exhibit No 797 Item Score Remarks : Perfect Allowed Flavor 40 Holes and appearance . . . 25 Texture 20 Salt 10 Style 5 Total 100 Date scored. Judges -I LIMBURGER CHEESE SCORE CARD. Limburger cheese is subject to most of the defects that are common to other kinds. Its peculiar flavor is not easy to obtain without defect, as in the process of manufacture it is difficult to control some of the common undesirable forms of bacteria when they once gain entrance to the milk from which the cheese is made. Gassy cheese is a common defect due to the presence of gas forming bacteria. The body of the cheese is filled with gas holes and bloats until the sides are more or less bulged and rounded. Too much acid development results in sour cheese that cures slowly and develops a bitter taste. Other defects are dry- ness which causes the cheese substance to be hard and to cure slowly, while too much moisture results in a pasty, rapidly cur- ing cheese that will not hold its shape well. The cheese should keep its regular shape, the substance should be uniform through- out and the rind free from cracks. 798 ScoRK Cards Owner . Address Class ... SCORE CARD FOR LIMBURGER CHEESE, Date received Exhibit No Item Score Perfect Allowed Flavor 40 Texture 40 Color 10 Salt 5 Style 5 Total . ; 100 Date scored. r Judges -j SCORE CARD FOR ICE CREAM. The scoring of ice cream does not differ materially from the scoring of other dairy products excepting that in judging quality in added flavor the ideal for the flavor used should be the stand- ard of comparison. The principal factors that have an influence on quality in ice cream are usually described under the follow- ing headings : Flavor, body, texture, appearance, and package. Flavor: Flavor may be described under two headings, (1) that derived from added flavoring, (2) that derived from other materials. If the added flavoring is not of high quality it may introduce "foreign" flavors and leave the cream "low" in the desired flavor. If too much flavoring is added it may be so pronounced as to taste too "sharp" or slightly "bitter", leaving a sensation that is slightly unpleasant. There should be just sufficient flavoring present to enable the consumer to identify it but not enough to smother or detract from the pleasant taste of other high grade materials present. "Rancid", "mouldy" and "stale" flavors may be derived from carelessly sorted nut meats and fruits. Sweetness should not be too pronounced, nor lack- ing to such an extent as to produce a "flat" taste. The flavors imparted to ice cream by milk products are nu- merous and variable in strength. The highest quality yields to let Cream 799 the tongue and palate the delicate aroma and sensation of rich- ness that is so pleasing in sweet, fresh, clean cream. Some be- lieve that a slightly acid development, hardly enough to be recog- nized, tends to liven the flavor and improve it. All of the flavors that appear in milk or cream of poor quality may be carried into the frozen product. The common ones are sour, old, cowey, bit- ter, metallic, oily, muddy, barn, unclean, burned and overheated flavors. Other defects in flavor may be due to other ingredients added. Milk powder, condensed milk, gelatin and starch when added, each impart at times, partieularily if these products are not of first quality, defects in flavor characteristic of the products them- selves. Body or Viscosity. — Ice Cream should be firm and yet not sticky. Texture. Smooth and velvety to the taste. No large water crystals. No milk sugar crystals causing "sandiness". Defects in texture are described as icy, coarse, sticky, buttery or soft. Allowance must always be made for fruits or nuts added in manufacturing. Composition. — The ice cream should not fall under the legal or trade standards. Both the fat and total solids should be taken into consideration. Increased importance is being attached to composition when scoring ice cream. Bacteria. The bacterial content is frequently overlooked, and more importance should be attached to it. Baer^ states : "The bacterial content of a perfect ice cream should be not more than 20,000 to the cc. One point should be deducted for every increase of 10,000 bacteria to the cc, until 100,000 is reached, when two points should be deducted for every increase of 50,000 to the cc". Appearance. The color should be characteristic of the fruit or flavor used. The general appearance should be clean. Package. Container to be clean, free from rust and from all evidences of slovenly workmanship. Brick ice cream should be neatly packaged. Several ice cream cards have been proposed, but none have been generally accepted. The four best known are as follows : 800 ScoRr; Cards (1.) Vermont Score Card/ Flavor 45 Texture 20 Richness 20 Appearance 10 Color 5 100 (2.) Iowa Score Card/ Flavor 45 Body 20 Texture 20 Permanency 10 Package 5 100 (3.) Wisconsin Score Card." Flavor 40 Bacteria 20 Texture and body. 20 Fat 10 Appearance & color 5 Package 5 100 California Score Card." Approved by Dairy Division, Uni- versity of California, Davis, Calif. Items Possible Score Amount Allowed Flavor and palatability .... 50 Texture and bodv 25 Appearance (color) 10 "A" butterfat 5 "B" total solids 10 Total 100 Analysis : Per cent Remarks : Butterfat Total solids "A"- — A perfect score shall be allowed ice cream containing 10-12 per cent butterfat, inclusive. Deduct 1 point for each Vs per cent above 12 per cent. Less than 10 per cent score' is 0. "B" — A perfect score shall be allowed ice cream containing 36 per cent total solids or above. For each per cent less than 36 per cent, deduct 2 points. Judges I While the manuscript for this cliapter was being set up there appeared the "Report of the Committee on Legal Standards and Score Cards for Dairy Products" of the American Dairy Science Association.- The following is taken from the above report: Condensed Milk 801 (5). Score card for ice cream tentatively recommended by the above committee : Flavor 40 Body and texture 25 Fat and solids 10 Bacteria 20 Package 5 100 SCORE CARD FOR PLAIN SUPERHEATED CONDENSED WHOLE OR SKIM-MILK. The authors are suggesting the following score card for plain superheated condensed whole or skim-milk. Explanation ac- companies each item to be scored. Products of this class are practically always marketed in bulk. Suggested Score Card for plain superheated whole or skim-milk. Item Score Allowed Remarks Viscosity 15 Heavy viscosity. Product to flow freely from container. Homogeneity 15 Smooth, velvety appear- ance. No visible specks or lumps. Ctolor 10 Light, white, milky color. Flavor 30 Good, clean milk flavor. No foreign flavors. Odor 5 No appreciable odors of any kind. Appearance c o n - tainer . . . 5 Container to be neat, clean and with all evi- dences of good work- manship. Fat 10 No foreign fats. Fat content to conform to legal or trade require- ments. Total solids 10 No preservatives of any kind. Total solids to conform to legal or trade requirements. Total 100 802 vScoRR Cards SCORE CARD FOR EVAPORATED MILK. No score cards for evaporated milk are known to have been published. The authors are suggesting the following score card, which takes into consideration the physical properties, appearance of the container, composition and net weight. Explanation is made of each item to be scored. Among the more common defects encountered when scoring evaporated milk to determine its commercial value, the follow- ing can be mentioned : (1). Viscosity either too light or too heavy, due to improper processing, or to incorrect handling after sterilizing. (2). Fat separated due to improper homogenization. (3). Color either too light due to insufficient sterilization, or too dark due to excessive sterilization or to the age of the product. (4), Off flavor caused by foreign substances, or by decom- position due to bacterial development when the product is not properly sterilized. The use of raw milk products of poor quality may cause off flavors. (5). Off odors caused usually by bacterial development as a result of improper sterilization. (6), Sediment upon bottom of cans, caused by the crystal- lization of the lime salt of citric acid. This appears only in prod- ucts of considerable age. Particles of foreign matter and lumps of coagulated casein, are sometimes found. (7). Evaporated milk is usually served at the table out of the original container. For this reason defects in the package should be carefully noted. Soiled and poorly applied labels and dirty or rusty cans all deduct from the score. (8). The composition and net weight of the cans are of great commercial importance. If under the advertised claims, it detracts from the commercial value of the product, and the score should be very liberally cut. No foreign fats or preservatives of any kind should be present. Evaporated Milk 803 SUGGESTED SCORE CARD FOR EVAPORATED MILK. Owner Date Address Brand Plant where manufactured Size. Item Score Remarks : Perfect Allowed Viscosity 15 Good viscosity, but not enough to flake in water or coffee. Suf- ficient to convey correct impres- sion of its value. Homogeneity . . 15 No fat separated. No specks or lumps. Product smooth and homogeneous throughout. Color 5 Medium color like heavy cream. Neither too white nor too dark. Sufficient color to insure safe sterilization. Flavor 30 Rich, nutty flavor. Cooked taste not too pronounced. No foreign flavors. Odor 2 No appreciable odors of any kind. Sediment 3 No lumps of coagulated casein. No foreign matter. No precipi- tate of calcium citrate. Appearance con- tainer 5 Neat labels properly applied. Ends of cans well polished, and not bulged. Fat 10 No foreign fats. No preservatives. Fat content to conform to legal requirements. Total solids .. 10 Total solids content to be not un- der legal requirements. Net weight . . . 5 Net weight to be not under amount specified upon the label. Total 100 The following score card for evaporated milk is taken from the "Report of the Committee on Legal Standards and Score Cards," cited above -^ Tentative Score Card for Evaporated Milk recommended by- above committee : 804 Score Cards Flavor and odor 40 Body and texture 35 Color 5 Fat content 10 Total solids 10 Adulterants and preservatives must be absent 100 The following comments are made by the committee upon the various points in the above score : Flavor and odor. Perfect : Must be fresh, sweet and free from off flavors. Deduct 1 to 10 points if metallic, rancid and stale. Deduct 40 points if sour, bitter, putrid, gassy or other- wise fermented. Body and texture. Perfect: Must be creamy, of uniform emulsion, smooth. Deduct 1 to 10 points each for curdy milk, separated or churned milk. Color. Perfect: Must be creamy. Deduct 1 to 3 points if brown. Fat content. Perfect: Must contain not less than 9 per cent milk fat. Deduct one point for each one-half per cent less than 9 per cent. Deduct 10 points if less than 7.8 per cent, the present Federal Standard. Total solids. Perfect: Must contain not less than 28 per cent solids. Deduct 1 point for each 1 per cent or fraction thereof, less than 28 per cent. Deduct 10 points if below 25,5 per cent, present federal standard. Adulterants and preservatives. Perfect : Must be free from all adulterants or preservatives. If it contains animal or vege- table fats, or other ingredients foreign to the composition of normal milk, or any preservatives deduct 100 per cent. SCORE CARD FOR SWEETENED CONDENSED MILK The authors are suggesting the following score card for sweet- ened condensed skim-milk. It takes into consideration the phys- SwiCiiTiiNKD Condensed MitK 805 ical properties, appearance of the container, composition and net weight. The same score card can be applied with slight modifi- cation to both the whole and skim-milk. The various physical properties are the same in either case. In the case of the sweet- ened condensed skim-milk, the score allowed under fat can be included with the total solids, since composition is of equal im- portance in either case, and upon it depends to a large extent the commercial value of the product. Brief explanation follows each item in the score. Large quantities of sweetened condensed milk are sold in bulk, being marketed either in barrels or in milk cans. Bulk sweet- ened condensed milk can be judged by using the same scale of points as in the case of the canned milk. The appearance of the container is of importance whether the product is marketed in bulk or in cans. The more common defects encountered in scoring sweetened condensed milk, are the following : (1). Viscosity either too light, or too heavy. (2). Fat separated upon the top of the milk or milk sugar separated upon the bottom of the container. These defects oc- cur in varying degrees. Lumps and specks rendering product not homogeneous. (3). Product slightly or badly discolored, caused by im- proper manufacturing processes. (4). Off flavors caused by mould development. Too much cooked or burned taste. Yeasty flavors. (5). Bad odors described as manurial, tallow, rancid or yeasty. (6). Container lacks neatness. Too much air space on top of the milk in the container. (7). Composition and net weight under standard claimed, whicli detracts considerablv from the score. 806 Score Cards SUGGESTED SCORE CARD FOR SWEETENED CONDENSED MILK Owner Date Address Brand Size Plant Item Score Allowed Eemarks : Viscosity 10 Neither too light nor too heavy in viscosity. Sufficiently fluid to pour from container. Homogeneity . . . 10 No fat separated. No milk sugar set- tled upon bottom of container. Product smooth to taste and free from foreign matter. Color ! 6 Slight yellowish cast. Neither too light nor too dark. Flavor 25 Clean milk flavor without any foreign flavor other than the sugar added. Odor 2 No appreciable odors of any kind. No signs of yeast development. Solubility 5 Product to dissolve freely in water, without showing any undissolved matter. Appearance o f container . . . 3 Neat label, properly applied.. No rust spots upon tin surfaces. If bulk container, should be neat and at- tractive. Bacteria 10 Bacteria to be present in amounts not to exceed the limits found in prop- erly pasteurized milk. No yeast cells to be present. Fat 10 Fat to be not under legal or trade standards. Score for fat to be add ed to total solids in the case of the skimmed product. No foreign fats allowed. Sugar 5 For sweetened condensed skim-milk, sugar to be about 42.00 per cent, and for whole milk about 44.50 per cent. Total solids . 10 Milk solids to conform to legal stand- ards. Total solids to conform to trade standards. No adulterants. Net weight . . . 5 To be not under amount specified upon the label. Total 100 The following score card for sweetened condensed milk is taken from - cited above. SwKKTKNKI) CONDF.NSKD MiLK 807 Tentative score card for sweetened condensed milk, recom- mended by the above coniinittee : SCORE CARD FOR SWEETF:NED CONDENSED MILK. Perfect score, Properties. per cent. Flavor and odor 30 Body and texture 25 Color 5 Fat content 10 Milk solids 10 Bacteria 10 Sugar 10 Adulterants and preservatives (must be absent) Total score 100 SUGGESTIONS FOR USE OF SCORE CARD. Flavor and odor. Perfect ; must be fresh, sweet and free from all flavors. Deduct one to ten points each if metallic, rancid, stale, cheesy. Deduct one to thirty points if sour, yeasty or other- wise fermented. Body and Texture. — Perfect: Must be viscous, smooth and free from lumps of curd, sugar sediment and foreign impurities. Deduct one to five points if rough and sandy, from one to five points if sugar sediment in bottom, from one to five points if fat separation, one to five points if white and yellow buttons, 15 to 25 points if lumps of curd. Color. — Perfect : Rich cream to yellow. Deduct one to five points if brown. Fat Content. — Perfect : Must contain not less than 10 per cent milk fat. Deduct one point for each half per cent less than 10 per cent. If below 8 per cent, deduct ten points. Deduct ten points if below 8 per cent, present Federal Standard. Total Milk Solids. — Perfect: Must contain not less than 32 per cent. Deduct one point for each per cent or fraction thereof below 32 per cent. If below 28 per cent, deduct ten points. 808 Score Cards Sugar. — Perfect: The concentration shall be from 60 to 62 per cent. Deduct two points for each per cent concentration below 60 or above 62 per cent. The concentration shall be deter- mined by dividing per cent of sugar by the sum of per cent of sugar and water. Bacteria. — Make reduction for excessive number of bacteria. Importance of bacterial counts have not as yet been sufficiently considered by the committee to Avarrant definite recommendations SCORE CARDS FOR WHOLE MILK, SKIM-MILK AND CREAM POWDERS. The authors are suggesting the following score card for vari- ous powdered milk products. Explanations follow the various items that go to make up the score. Flavor. — This largely determines the commercial value of all milk powders. The first signs of decomposition usually manifest themselves in the flavor. The principal defect in flavor is caused by rancidity. Any considerable amount of rancidity renders the powder unfit for human food. No method of treatment has yet been found that will completely eliminate rancidity after it has been once developed. The flavor should be very similar to that of the fluid products from which the powders were made. Odor. — No bad odors of any kind should be noticeable. Bad odors usually indicate either improper manufacturing processes, or decomposition of the product. Solubility. — The importance of solubility depends upon the use to which the powder is to be placed. Powder made by the spray process is usually more soluble than that made by the roller process. If the powder is to be reconstituted or used for making ice cream, it is very important that it be completely soluble. If it is used for making milk chocolate and other food products, its solubility is relatively not important. Appearance. — White to slightly yellowish cast. No dark lumps or specks. Powder is to be homogeneous throughout. Composition. — Water content not to exceed the Federal Stand- ard of 5 per cent. The less water the better, since the presence of water is the most common cause of spoilage. The fat and total solids are to conform to the legal or trade requirements. Milk Powders 809 SCORE CARDS FOR WHOLE MILK, SKIM-MILK AND CREAM POWDERS. Item Score Allowed Remarks : Flavor 50 Fresli, clean flavor resembling that of the fluid products. No signs of rancidity. Odor 5 Clean, agreeable odor. Suggestion of good milk products. Solubility .... 10 For certain iises, powder should be completely soluble. For other uses solubility is relatively unimport- ant. Appearance . . . 10 15 10 Pleasing appearance. Homogeneous and free from lumps or specks. Composition Not to exceed 5 per cent of water. Bacteria Not to exceed limits usually found in properly pasteurized milk. REFERENCES. 1 Whitaker, G. M. The Score Card System of Dairy Inspection. Bu. Am. Ind. U. S. Dept. Agri. Cir. 199,122. - Frandsen, J. H. Chairman "Report of Committee on Legal Standards and Score Cards for Daii-y Products." Journal of Dairy Science, March 1922, p. 164. » Washburn, R. M. Vermont Station, Bulletin 155, 1910. * Mortensen, M. Iowa Station, Bulletin 123. = Baer, A. C. Wisconsin Station, Bulletin 262, 1916. " California and Southwestern States Ice Cream Manufacturers Ass'n. 1921. CHAPTER XXI DEFINITIONS AND STANDARDS FOR DAIRY AND RELATED PRODUCTS Standards for dairy products group themselves into three sub- divisions : namely, federal,, state and municipal standards. Ob- viously these are continuously undergoing changes, and the marked lack of uniformity is very evident. STANDARDS OF THE U. S. DEPARTMENT OF AGRICULTURE. The following definitions and standards are taken verbatim from the federal regulations as promulgated by the TJ. S. Secre- tary of Agriculture down to the time of going to press.^ These definitions and standards are all a result of the labors of the "Joint committee on Food and Drug definitions and standards" of which Dr. Julius Hortvet is chairman. The definitions have been adopted in whole or in part by many of the state authorities. Milk and Milk Products Milk. — 1. Milk is the whole, fresh, clean lacteal secretion ob- tained by the complete milking of one or more healthy cows, properly fed and kept, excluding that obtained within fifteen days before and five days after calving, or such longer period as may be necessary to render the milk practically colostrum-free. 2. Blended milk is milk modified in its composition so as to have a definite and stated percentage of one or more of its con- stituents. 3. Pasteurized milk is milk that has been subjected to a temp- erature not lower than 145 degrees Falirenheit for not less than thirty minutes. Unless it is bottled hot, it is promptly cooled to 50 degrees Fahrenheit, pr lower. 4. Sterilized milk is milk that has been lieated at the tempera- ture of boiling water or higher for a length of time sufficient to kill all organisms present. [810] - Mii^K AND Milk Products 811 5. Homogenized milk is milk that has been mechanically treated in such a manner as to alter its physical properties with particular reference to the condition and appearance of the fat globules, , 6. Skimmed milk is milk from which substantially all of the milk fat has been removed, 7. Buttermilk is the product that remains when fat is re- moved from milk or cream, sweet or sour, in the process of churn- ing. It contains not less than eight and five-tenths per cent (8.5%) of milk solids not fat. 8. Goat's milk, ewe's milk, et cetera, are the fresh, clean, lacteal secretions, free from colostrum, obtained by the complete milking of healthy animals other than cows, properly fed and kept, and conform in name to the species of animal from which they are obtained. 9. Condensed milk, evaporated milk, concentrated milk, is the product resulting from the evaporation of a considerable portion of the water from the whole, fresh, clean lacteal secretion ob- tained by the complete milking of one or more healthy cows, properly fed and kept, excluding that obtained within fifteen days before and ten days after calving, and contains, all tolerances being allowed for, not less than twenty-five and five-tenths per cent (25,5%) of total solids and not less than vseven and eight- tenths per cent (7,8%) of milk fat. In the case of the standard upon evaporated milk, a tentative standard, wherever standardization is being practiced, of 8,00 per cent fat and 26.15 per cent total solids is the one that applies. 10. Sweetened condensed milk, sweetened evaporated milk, sweetened concentrated milk, is the product resulting from the evaporation of a considerable portion of the water from the whole, fresh, clean, lacteal secretion obtained by the complete milking of one or more healthy cows, properly fed and kept, excluding that obtained within fifteen days before and ten days after calv- ing, to which sugar (sucrose) has been added. It contains, all tolerances being allowed for, not less than twenty-eight per cent (28.0%) of total milk solids, and not less than eight per cent (8.0%) of milk fat, 11. Condensed skimmed milk, evaporated skimmed milk, con- centrated skimmed milk, is the product resulting from the evapo- 812 Definitions and »Standards ration of a considerable portion of the water from skimmed milk, and contains, all tolerances being allowed for, not less than twenty per cent (20%) of milk solids. 12. Sweetened condensed skimmed milk, sweetened evapo- rated skimmed milk, sweetened concentrated skimmed milk, is the product resulting from the evaporation of a considerable portion of the water from skimmed milk to which sugar (sucrose) has been added. It contains, all tolerances being allowed for, not less than twenty-eight per cent (28.0%) of milk solids. 13. Dried milk is the product resulting from the removal of water from milk, and contains, all tolerances allowed for, not less than twenty-six per cent (26.0%) of milk fat, and not more than five per cent (5.0%c) of moisture. 14. Dried skimmed milk is the product resulting from the removal of water from skimmed milk, and contains, all tolerances allowed for, not more than five per cent (5.0%) of moisture. 15. Malted milk is the product made by combining whole milk with the liquid separated from a mash of ground barley malt and wheat flour, with or without the addition of sodium chloride, sodium bicarbonate, and potassium bicarbonate in such a manner as to secure the full enzymic action of the malt extract and by re- moving water. The resulting product contains not less than seven and one-half per cent (7.5%o) of butter fat and not more than three and one-half per cent (3.5% ) of moisture. Cream. 1. Cream, sweet cream, is that portion of milk, rich in milk fat, which rises to the surface of milk on standing, or is sepa- rated from it by centrifugal force. It is fresh and clean. It con- tains not less than twenty per cent (20.0%o) of milk fat and not more than two-tenths per cent (0.2%) of acid-reacting substances, calculated in terms of lactic acid, 2. Whipping cream is cream which contains not less than thirty per cent (30.0%c) of milk fat. 3. Homogenized cream is cream that has been mechanically treated in such a manner as to alter its physical properties, with particular reference to the condition and appearance of the fat globules. 4. Evaporated cream, clotted cream, is cream from which a considerable poi'tion of water has been evaporated. Cheese; 813 Cheese. 1. Cheese is the sound product made from curd ob- tained from the whole, partly skimmed, or skimmed milk of cows, or from the milk of other animals, with or without added cream, by coagulating the casein with rennet, lactic acid, or other suit- able enzj'me or acid, and with or without further treatment of the separated curd by heat or pressure, or by means of ripening fer- ments, special molds, or seasoning. By act of congress, approved June 6, 1896, cheese may also contain added coloring matter. In the United States, the name ' ' Cheese ' ' unqualified, is under- stood to mean Cheddar Cheese, American Cheese, American Cheddar Cheese. 2. Whole milk cheese is cheese made from whole milk. 3. Partly skimmed milk cheese is cheese made from partly skimmed milk. 4. Skimmed milk cheese is cheese made from skimmed milk. Whole Milk Cheeses. 5. Cheddar cheese, American cheese, American Cheddar cheese, is the cheese made by the Cheddar process, from heated and pressed curd obtained by the action of rennet on whole milk. It contains not more than thirty-nine per cent (39%) of water, and, in the water-free substance, not less than fifty per cent (50%) of milk fat. 6. Stirred curd cheese, sweet curd cheese, is the cheese made by a modified Cheddar process, from curd obtained by the action of rennet on whole milk. The special treatment of the curd, after the removal of the whey, yields a cheese of more open, granular texture than Cheddar cheese. It contains, in the water-free sub- stance, not less than fifty per cent (50%) of milk fat. 7. Pineapple cheese is the cheese made by the pineapple Cheddar cheese process, from pressed curd obtained by the action of rennet on whole milk. The curd is formed into a shape re- sembling a pineapple, with characteristic surface corrugations, and during the ripening period the cheese is thoroughly coated and rubbed with a suitable drying oil, with or without shellac. It contains, in the water-free substance, not less than fifty per cent (50%) of milk fat. 8. Limburger cheese is the cheese made by the Limburger process, from unpressed curd obtained by the action of rennet on 814 Definitions and Standards whole milk. The curd is ripened in a damp atmosphere by special fermentation. It contains, in the water-free substance, not less than fifty per cent (50%) of milk fat. 9. Brick cheese is the quick-ripened cheese made by the brick cheese process, from pressed curd obtained by the action of rennet on whole milk. It contains, in the water-free substance, not less than fifty per cent (50%) of milk fat. 10. Stilton cheese is the cheese made by the Stilton process from unpressed curd obtained by the action of rennet on whole milk, with or without added cream. The cheese, ripened by a special blue-green mold, has a mottled or marbled appearance in section. 11. Gouda cheese is the cheese made by the Gouda process, from heated and pressed curd obtained by the action of rennet on whole milk. The rind is colored with saffron. It contains, in the water-free substance, not less than forty-five per cent (45%) of milk fat. 12. Neufchatel cheese is the cheese made by the Neufchatel process, from unheated curd obtained by the combined action of lactic fermentation and rennet on whole milk. The curd, drained by gravity and light pressure, is kneaded or worked into a but- ter-like consistence and pressed into forms for immediate con- sumption or for ripening. It contains, in tlie water-free substance, not less than fifty per cent (50*/^ ) of milk fat. 13. Cream cheese is the unripened cheese made by the Neuf- chatel process from whole milk enriched with cream. It contains, in the water-free substance, not less than sixty-five per cent (65%) of milk fat. 14. Koquefort cheese is the cheese made by the Roquefort process, from unheated, unpressed curd obtained by the action of rennet on the whole milk of sheep, with or without the addition of a small proportion of the milk of goats. The curd is inoculated with a special ripening mold (Penicillium Roqueforti) and ripens with the growth of the mold in the interior. The fully ripened cheese is friable and has a mottled or marbled appearance in section. 15. Gorgonzola cheese is the cheese made by the Gorgonzola process, from curd obtained by the action of rennet on whole milk. i Chijksiv 815 The cheese, ripened in a cool, moist atmosphere by the develop- ment of a bhie-green mold, has a mottled or marbled appearance in section. Whole Milk or Partly Skimmed Milk Cheeses. 16. Edam cheese is the cheese made by the Edam process, from heated and pressed curd obtained by the action of rennet on Avhole milk, or on partly skimmed milk. It is commonly made in spherical form and coated with a suitable oil and a harmless red coloring matter. 17. Emmenthaler cheese, Swiss cheese, is the cheese made by the Emmenthaler process, from heated and pressed curd obtained by the action of rennet on whole milk or on partly skimmed milk, and is ripened by special gas-producing bacteria, causing charac- teristic "eyes" or holes. The cheese is also known in the United States as "Schweitzer." It contains, in the water-free substance, not less than forty-five per cent (45%) of milk fat. 18. Camembert cheese is the cheese made by the Camembert process, from unheated, unpressed curd obtained by the action of rennet on whole milk or on slightly skimmed milk, and is ripened by the growth of a special mold (Penicillium Camemberti) on the outer surface. It contains,, in the water-free substance, not less than forty-five per cent (45%) of milk fat. 19. Brie cheese is the cheese made by tlie Brie process, from unheated, unpressed curd obtained by the action of rennet on whole milk, on milk with added cream, or on slightly skimmed milk, and is ripened by the growth of a special mold on the outer surface. 20. Parmesan cheese is the cheese made by the Parmesan process, from heated and hard-pressed curd obtained by the action of rennet on partly skimmed milk. The cheese, during the long ripening process, is coated with a suitable oil. Skimmed Milk Cheeses. 21. Cottage cheese, Schmierkase, is the unripened cheese made from heated (or scalded) curd ob- tained by the action of lactic fermentation or lactic acid or rennet, or any combination of these agents, on skimmed milk, with or without the addition of butter-milk. The drained curd is some- times mixed Avith cream, salted, and sometimes otherwise seasoned. Whey Cheeses. 22. Whey cheese (so called) is produced by various processes from the constituents of whey. There are a 816 Definitions and Standards number of varieties each of which bears a distinctive name, ac- cording to the nature of the process by which it has been pro- duced, as, for example, "Rieotta," "Zieger, " "Primost, " "My- sost." Sugar and Sugar Products — Sugars. 1. Sugar is the product chemically known as sucrose (saccharose), chiefly obtained from sugar cane, sugar beets, sorghum, maple and palm. 2. Granulated, loaf, cut, milled, and powdered sugars, are different forms of sugar, and contain at least ninety-nine and five- tenths per cent (99.5%) of sucrose. 3. Maple sugar, maple concrete, is the solid product resulting from the evaporation of maple sap or maple syrup. 4. Massecuite, melada, mush sugar, and concrete, are products made by evaporating the purified juice of a sugar-producing plant, or a solution of sugar, to a solid or semi-solid consistence, and in which the sugar chiefly exists in a crystalline state. Molasses and Refiners' Syrup. 1. Molasses is the product left after separating the sugar from massecuite, melada, mush sugar, or concrete, and contains not more than twenty-five per cent (25%) of water and not more than five per cent (5%) of ash. 2. Refiners' syrup, treacle, is the residual liquid product ob- tained in the process of refining raw sugars, and contains not more than twenty-five per cent (25% ) of water and not more than eight per cent (8%) of ash. S3nnips. 1. Syrup is the sound product made by purifying and evaporating the juice of a sugar-producing plant without re- moving any of the sugar. 2. Sugar-cane syrup is syrup made by the evaporation of the juice of the sugar-cane or by the solution of sugar-cane concrete, and contains not more than thirty per cent (30%) of water and not more than two and five-tenths per cent (2.5%) of ash. 3. Sorghum syrup is syrup made by the evaporation of sor- ghum juice or by the solution of sorghum concrete, and contains not more than thirty per cent (30% ) of water and not more than tAvo and five-tenths per cent (2.5%) of ash. 4. Maple syrup is syrup made by the evaporation of maple sap or by the solution of maple concrete, and contains not more Glucose Pkoducts 817 than thirty-five per cent (35%) of water, and weighs not less than eleven (11) pounds to the gallon (231 cu. in.) 5. Sugar syrup is the product made by dissolving sugar to the consistence of a syrup, and contains not more than thirty-five per cent (35%) of water. Glucose Products. 1. Starch sugar is the solid product made by hydrolyzing starch or a starch-containing substance until the greater part of the starch is converted into dextrose. Starch sugar appears in commerce in two forms, anhydrous starch sugar and hydrous starch sugar. The former, crystallized without water of crystallization, contains not less than ninety-five per cent (95%) of dextrose and not more than eight-tenths per cent (0.8%) of ash. The latter, crystallized with water of crystalliza- tion, is of two varieties: 70 sugar, also known as brewers' sugar, contains not less than seventy per cent (70%) of dextrose and not more than eight-tenths per cent (0.8%) of ash; 80 sugar, climax or acme sugar, contains not less than eighty per cent (80%) of dextrose and not more than one and one-half per cent (1.5%) of ash. Honey. 1. Honey is the nectar and saccharine exudations of plants gathered, modified and stored in the comb of honey bees (Aphis mellifica and A. dorsata) ; is laevo-rotatory, contains not more than twenty-five per cent (25%) of water, not more than twenty-five hundredths per cent (.25%) of ash, and not more than eight per cent (8%) of sucrose. 2. Comb honey is honey contained in the cells of comb, 3. Extracted honey is honey which has been separated from the uncrushed comb by centrifugal force or gravity. 4. Strained honey is honey removed from the crushed comb by straining or other means. Cacao Products. 1. Cacao beans, cocoa beans, are the seeds of the cacao tree, Theobroma cacao L. 2. Cacao nibs, cocoa nibs, cracked cocoa, is the roasted, broken cacao bean freed as far as is practicable from cacao shell or husk. 3. Chocolate, plain chocolate, bitter chocolate, chocolate liquor, chocolate paste, bitter chocolate coating, is the solid plastic mass obtained by grinding cacao nibs without the removal of fat or other constituents except the germ, and contains not less than fifty per cent (50%) cacao fat and, on the moisture and fat-free 818 Definitions and Standards basis, not more than eight and five-tenths per cent (8.5%) total ash, not more than four-tenths per cent (0.4%) ash insoluble in hydrochcloric acid, not more than five and six-tenths per cent (5.6%) ash insoluble in Avater, not more than seven per cent (1%) crude fiber, not more than four per cent (4%) cacao shell. 4. Sweet chocolate, sweet chocolate coating, is chocolate mixed with sugar (sucrose), with or without the addition of cocoa butter, spices, or other flavoring material, and contains on the moisture, sugar and fat-free basis, no higher percentage of total ash, ash insoluble in hyrochloric acid, ash insoluble in water, crude fiber, or cacao shell, respectively, than is found in the moisture and fat-free residue of chocolate. 5. Cocoa, powdered cocoa, is chocolate deprived of a portion of its fat and finely pulverized and contains not less than twenty per cent (20%) cacao fat and, on the moisture and fat-free basis, no higher percentage of total ash, ash insoluble in hydrochloric acid, ash insoluble in water, crude fiber, or cacao shell, respec- tively, than is found in the moisture and fat-free residue of chocolate. 6. Sweet cocoa, sweetened cocoa, is cocoa mixed with sugar (sucrose), and contains not more than sixty per cent (60%) sugar in the finished product, and, on the moisture, sugar and fat-free basis, no higher percentage of total ash, ash insoluble in hydrochloric acid, ash insoluble in water, crude fiber, or cacao shell respectively, than is found in the moisture and fat-free residue of chocolate. 7. Milk chocolate, milk cocoa, sweet milk chocolate, and sweet milk cocoa, are chocolate, cocoa, sweet chocolate, and sweet cocoa, respectively, to which milk has been added in the course of their preparation and which contain not less than twelve per cent (12%) of whole milk solids in the finished product. Flavoring Extracts. — 1. A flavoring extract is a solution in ethyl alcohol of proper strength of the sapid and odorous prin- ciples drived from an aromatic plant, or parts of the plant, with or without its coloring matter, and conforms in name to the plant used in its preparation. 2. Almond extract is the flavoring extract prepared from oil of bitter almonds, free from hydrocyanic acid, and contains not less than one per cent (1%) by volume of oil of bitter almonds. Extracts 819 2a. Oil of bitter almonds, commercial, is the volatile oil ob- tained from the seed of the bitter almond (Amygdalus communis L.), the apricot (Primus armeniaca L,), or the peach (Amygdalus persica L.). 3. Anise extract is the flavoring extract prepared from oil of anise, and contains not less than three per cent (3%) of oil of anise. 3a. Oil of anise is the volatile oil obtained from the anise seed. 4. Celery seed extract is the flavoring extract prepared from celery seed or the oil of celery seed, or both, and contains not less than three-tenths per cent (0.3%) by volume of oil of celery seed. 4a. Oil of celery seed is the volatile oil obtained from celery seed. 5. Cassia extract is the flavoring extract prepared from oil of cassia, and contains not less than two per cent (2%) by volume of oil of cassia. 5a. Oil of cassia is the lead-free volatile oil obtained from the leaves or bark of Cinnamomum cassia Bl. and contains not less than seventy-five per cent (75%) by weight of cinnamic aldehyde. 6. Cinnamon extract is the flavoring extract prepared from oil of cinnamon, and contains not less than two per cent (2%) by volume of oil of cinnamon. 6a. Oil of cinnamon is the lead-free volatile oil obtained from the bark of the Ceylon cinnamon (Cinnamomum zeylanicum Breyne), and contains not less than sixty-five per cent (65%) by weight of cinnamic aldehyde and not more than ten per cent (10%) by weight of eugenal. 7. Clove extract is the flavoring extract prepared from oil of cloves, and contains not less than two per cent (2%) by volume of oil of cloves. 7a. Oil of cloves is the lead-free, volatile oil obtained from cloves. 8. Ginger extract is the flavoring extract prepared from ginger, and contains in each one hundred (100) cubic centimeters the alcohol-soluble matters from not less than twenty (20) grams of ginger. 9. Lemon extract is the flavoring extract prepared from oil of lemon or from lemon peel, or both, and contains not less than five per cent (5%) by volume of oil of lemon. 820 Definitions and Standards 9a. Oil of lemon is the volatile oil obtained, by expression or alcoholic solution, from the fresh peel of the lemon (Citrus Limo- mum L.), has an optical rotation (25° C.) of not less than +60° in a 100-millimeter tube, and contains not less than four per cent (4%) by weight of citral. 10. Terpeneless extract of lemon is the flavoring extract prepared by shaking oil of lemon with dilute alcohol, or by dis- solving terpeneless oil of lemon in dilute alcohol, and contains not less than two-tenths per cent (0.2%) by weight of citral de- rived from oil of lemon. 10a. Terpeneless oil of lemon is oil of lemon from which all or nearly all of the terpens have been removed. 11. Nutmeg extract is the flavoring extract prepared from oil of nutmeg, and contains not less than two per cent (2%) by volume of oil of nutmeg. 11a. Oil of nutmeg is the volatile oil obtained from nutmegs. 12. Orange extract is the flavoring extract prepared from oil of orange, or from orange peel, or both, and contains not less than five per cent (5%) by volume of oil of orange. 12a. Oil of orange is the volatile oil obtained, by expression or alcoholic solution, from the fresh peel of the orange (Citrus aurantium L.), and has an optical rotation (25°C.) of not less than +95° in a 100-millimeter tube. 13. Terpeneless extract of orange is the flavoring extract prepared b}^ shaking oil of orange with dilute alcohol, or by dissolving terpeneless oil of orange in dilute alcohol, and corre- sponds in flavoring strength to orange extract. 13a. Terpeneless oil of orange is oil of orange from which all or nearly all of the terpenes have been removed. 14. Peppermint extract is the flavoring extract prepared from oil of peppermint, or from peppermint, or both, and contains not less than three per cent (3%) by volume of oil of peppermint. 14a. Peppermint is the leaves and flowering tops of Mentha piperita L. 14b. Oil of peppermint is the volatile oil obtained from pepperment, and contains not less than fifty per cent (50%) by weight of menthol. Extracts 821 15. Rose extract is the flavoring extract prepared from otto of roses, with or withoiit red rose petals, and contains not less tlian four-tenths per cent (0.4%) by volume of otto of roses. 15a. Otto of roses is the volatile oil obtained from the petals of Rosa damaseent Mill., R. centrifolia L., or R. moschata Herrm. 16. Savory extract is the flavoring extract prepared from oil of savory, or from savory, or both, and contains not less than thirty-five hundredths per cent (0.35%) by volume of oil of savory. 16a. Oil of savory is the volatile oil obtained from savory. 17. Spearmint extract is the flavoring extract prepared from oil of spearmint, or from spearmint, or both, and contains not less than three per cent (3%) by volume of oil of spearmint. 17a. Spearmint is the leaves and flowerings tops of Mentha spicata L. 17b. Oil of spearmint is the volatile oil obtained from spear- mint. 18. Star anise extract is the flavoring extract prepared from oil of star anise, and contains not less than three per cent (3%) by volume of oil of star anise. 18a. Ojl of star anise is the volatile oil distilled from the fruit of the star anise (Illicium verum Hook). 19. Sweet basil extract is the flavoring extract prepared from oil of sweet basil, or from sweet basil, or both, and contains not less than one-tenth per cent (0.1%) by volume of oil of sweet basil. 19a. Sweet basil is the leaves and tops of Ocymum basili- cum L. 19b. Oil of sweet basil is the volatile oil obtained from basil. 20. Sweet marjoram extract, marjoram extract, is the flavor- ing extract prepared from the oil of marjoram, or from marjoram, or both, and contains not less than one per cent (1%) by volume of oil of marjoram. 20a. Oil of marjoram is the volatile oil obtained from marjoram. 21. Thyme extract is the flavoring extract prepared from oil of thyme, or from thyme, or both, and contains not less than two- tenths per cent (0.2%) by volume of oil of thyme. 822 Dkfinitions and 5>tandards 21a. Oil of thyme is the volatile oil obtained from thyme. 22. Tonka extract is the flavoring extract prepared from tonka bean, with or without sugar or glycerin, and contains not less than one-tenth per cent (0.1%) by weight of coumarin extracted from the tonka bean, together with a corresponding proportion of the other soluble matters thereof. 22a, Tonka bean is the seed of Coumarouna adorata Abulet (I^ipteryx odorata (Aubl.). Willd.) 23. Vanilla extract is the flavoring extract prepared from vanilla bean, with or without sugar or glycerin, and contains in one hundred (100) cubic centimeters the soluble matters from not less than ten (10) grams of the vanilla bean. 23a. Vanilla bean is the dried, cured fruit of Vanilla plani- folia Andrews. 24. Wintergreen extract is the flavoring extract prepared from oil of wintergreen, and contains not less than three per cent (3%) by volume of oil of wintergreen. 24a. Oil of wintergreen is the volatile oil distilled from the leaves of the Gaultheria procumbens L. The state and territorial standards prevailing, as far as could be ascertained at time of going to press, are given in Table 151. This table follows closely the legal standards for dairy products issued May 1st, 1916, by the U. S. Department of Agriculture, and which was subsequently revised by Taylor and Thomas.- Numerous further revisions have been made, based upon informa- tion contained in letters or circulars obtained at original sources. In a few instances it has been found impossible to obtain any con- firmatory information. STATE BACTERIA STANDARDS. The only states that have adopted bacteria standards are the following : California. — In milk as Note (1) ; cream as Note (2). Connecticut. — In milk 100,000 per cc, in cream 5,000,000 per cc. After pasteurizing in milk 50,000 per cc, in cream 100,000 per ee. Delaware.— In milk, 100,000 per cc, Cream as Note (7). Georgia. — In milk 500,000 per cc BACTIiKlA 823 Hawaii. — In milk, 1,000,000 per ce. Idaho. — In milk 500,000 per cc, cream, 500,000 ec. Montana. — In milk or ice cream, 500,000 per cc. New Hampshire. — In milk, 500,000 per cc. New York. — In milk and cream as Note (13). Oklahoma. — In milk as Note (16). Porto Rico.— In milk, 100,000 per cc. Vermont. — In milk, 200,000 per cc. Washington. — In milk, 400,000 per cc. STANDARDIZATION OF PASTEURIZATION— TIME AND TEMPERATURES. The States that have established control of pasteurization and the standards adopted are as follows : — Arizona. — 145° F, for 30 minutes. California.— 140-145° F. for 25 minutes. (5). Connecticut.— 142-148 °F. for 30 minutes. Delaware.— 145° F. for 30 minutes. Indiana.— 145° F. for 30 minutes or 160° F. for 30 seconds. (9). Iowa. — 145° F. for 30 minutes. Louisiana. — 140° F. for 20 minutes. Massachusetts. — 140-145° F. for 30 minutes. Michigan.— 145° F. for 30 minutes or 185° flash. Minnesota.— 145° F. for 30 minutes or 180° flasli. Montana. — 140-145° F. for 30 minutes. Nebraska. — (5). New Jersey.— 142-145° F. for 30 minutes. Nevada. — 140° F. for 25 minutes or 170° F. flash method. New York.— 142-145° F. for 30 minutes. Oklahoma. — 145° F. for 25 minutes, or 150° F. for 20 minutes, or 170° F., flash method. Oregon.— 140° F. for 30 minutes (5). Tennessee. — 145° F. for 30 minutes or 165° F. for 30 seconds. Vermont. — 145° F. for 30 minutes. Washington. — 140° F. for 25 minutes. Wyoming. — 145° F. for 30 minutes or 165° for 30 seconds. These standards Avere established in the manner indicated under the heading "Standards Established by" in the tables. 824 Definitions and Standards U =1 M -t-> I-) n •- < H -o 8 eS V -M BJ -M CO a > 13 'i -a m C r adoptio der legit Food De legislativ by Pubh nt undc nd Foo on unde ate Boar lative au nd Dair on unde th undc J3 W -3 c No state standards. No territorial standard Act of legislature. No state standards. Act of legislature. Act of legislature. Act of legislature. State Board of Health u lative authority. .\ct of Congress. Legislature provides fo of federal standards. State veterinarian un lative authority. Act of legislature and p'artment under authority. Act of legislature and Welfare Departme legislative authority. Act of legislature a Standard Commissi legislative authority. Act of legislature and St of Health under legis thority. By act of legislature s and Food Commiss legislative authority. State Board of Heal legislative authority. fe a^ : „ o ■ i o .S S-S _M a t^S — ' ^~* '. " : ■i:^ fee ^f-^ (^ f^6 •lO - io»o 3 A r. V "^ § : O" phj3 i t-l o o 1 ft, fee OOO CO oc C-l IM oo 00 O (M fe l^d " o fe o o ■ rt Pl^ 1 fee <^6 o oooo oc •* -J< 00 00 IM O -a a °'5 fe "S s? ^^ CO lO lO ^_^ »o tJ •*' irj >o " .o -£ ^^ (M 1 c ■a o 1 s fe "S 00 f5 oo 00 oo J5 oc ~~^ t>^ t^ t--^ ^^ t^ c 1 fee !^6 s* S : =" S S S & r'=^ fee M*^ tH ^^6 t^ ll fe P -n •CO • - CO CO S icS '"' ;§ i fe o ^6 oo W5 CM ^_^ U5 lO UO J3, M M C^ O O s^ _^ ?rt OC oo oo 00 00 CO oo ^Q a:^'B.'i fe "^ (^o oi 00 • • oi Oi en 05 05 .„ ; ■r: >.-5 r^* C-J CM (M ^ t^o . CO ■ cococo ■ CO CO CO CO CO CO CO -o^ ^ ^ : S CO ^c5 : oo • oo • 00 oo 00 00 oo (» . lO • 1 "rt-O fee : t^ Ahcj : " ;« i ^ ^ " ^ €*■ g o M * " "^ C« ;:j ^ «il^ig ^ a" C3 CO « 02 J 5 .i C -< 1 < III 1 5 "c r5 Hawai Idaho Illinois Indian o vStatr v^TANDARDS 825 ) < i.-^-? £t3 o T3^ O OS -a -3:2 o"© '3'H'o'o'o 2 9 f? 3 ^ JO — HH ►3 ^ 1 o^ -t- ho , cn^ ^ th— < A ' 3 a^ aja^ 3Q ? ■a^ •oW i3i >> <;cQ 00 OOQOOO 00 000000 00 0000 iiti 00 O 00 000 00 cq 00 o 00 kC 00 00 00 00 c •00 »o OC^ICI CO CO CO CO 10 iC 00 00 OS Ci 00 C^ ^H CJ ^ si w ^ s>^ 1 :! EC ^ a ^ iz; !z; o 826 Definitions and Standards i Drugs Act and alth under legis- ty. iry Department ve authority. 6. e Food and Drug legislative au- ug Department tive authority. ture and State alth under legis- ty. ent under legis- ty. e. Council under uthority. No Js. C3 -3 C ca o o'-S-a'i Ois-Q cj o >> S >, ■g-gpaiS gJ5-5-§.a!B-g-3 a.^ & fa Z<-< fa « fa -re M -2 ^ik CS P. fe "S (^ 00 00 00 00 i Us f:< 1^ t^ t^ t^ t^ 3:^:1 S e-~ o ire § s H^;g Ph^ — IM C-) >o C-) C-4 1 fe«^ ^ 1- oo M E-i ^cS" '- t>. t- 00 00 1 _^ |5 Ih e^cS" ^ ^ fea^ ^ .re fc fScS^ o oo § « o (MO 00 00 a s^s (ScSS 00 CO 00 (>JCO-H « _« a=5'3-S ^ : •OiO >0 lO c^ !^» ^S^,o f^o : 05 0J o ffl O! oo o .^ ^ pS f^cS" COM CO CO CO CO CO |o^ Ijs >OiO on lO >o o »re § TO 00 00 00 oo 00 00 00 T lO • KCi »C ^1 ^Js c< :^ w H -a o « fe 2 3 3? ? i a « ' i 1 °-gi c a?- c ' 11 1 c ° Ph ff ; a- TOfc- E- > > && is Notes 827 NOTES (1). Grade A. — raw— less than 100,000 bacteria per cc. Grade A — pasteurized — less than 200,000 bacteria per cc. before pasteurization: less than 15,000 after pasteurization. Grade B — less than 1 million bacteria per cc. before pasteurization; less than 50,000 after pasteurization. (2). Not more than two times the bacteria in the corresponding grade of milk. (3). U. S. Department of Agriculture Standards. (4). Half skim, 25 per cent fat. (5). Unless milk is from herds free from tuberculosis as evidenced by the tuberculin test. (6). Less than 50 per cent of total solids. (7). Raw cream — less than 500,000 bacteria per cc. Pasteurized cream — less than 250,000 bacteria per cc. (S). Bacteria standard for milk and ice cream is 500,000 per cc. (9). Compulsory pasteurization of milk products entering into the manu- facture of ice cream. (10). Fruit ice cream, 4 per cent fat: nut ice cream, 6 per cent fat. (11). Skim-milk from creameries required to be pasteurized to 180° F. (12). "By terms of law enacted in 1917. provision is made for the sale of milk, provided that such be 'pure natural milk' and that 'every can, bottle, or other container in which such milk is shipped, sold or delivered, at wholesale or retail, is plainly labeled so as to show its guaranteed composition.' " (13). Grade A, Raw: Milk — not more than 60.000 bacteria per cc. Cream — not more than 300,000 bacteria per cc. Grade A, pasteurized: (Milk or cream before pasteurization not more than 200,000 bacteria per cc") Milk — not more than 30,000 bacteria per cc. Cream — not more than 150,000 bacteria per cc. (Irrade B, raw: Milk — not more than 200.000 bacteria per cc. Cream — not more than 750.000 bacteria per cc. Grade B, pasteurized: (Milk or cream before pasteurization, no more than 1,500,000 bacteria per cc. ) Milk — not more than 100,000 bacteria per cc. Cream — not more than 500,000 bacteria per cc. (14). Cheese made from skimmed or partially skimmed milk must be branded with the words, "Skim-milk Cheese:" if it contains 13 per cent milk fat or over, it may be branded, "Medium Skim-milk Cheese." or if it contains IS per cent of milk fat or over, it may be bi-anded "Special Skim-milk Cheese." (15). Milk falling under the standard for whole milk shall be termed skim-milk. (16). "Bottled raw milk must not contain more than 100.000 bacteria from May 1 until Oct. 1. All pasteurized bottled milk not more than 50,000 in the same period of time." (17). "All milk and cream used in manufacture of creamery butter and ice cream for commercial purposes, and all milk bought to be resold, must be pasteurized." (IS). "If a person accused of violating section one of this act shall furnish satisfactory affidavit that nothing has been added to or taken from the milk in question, which is otherwise pure and wholesome, and is not below three (3) per centum of butterfat. ... no prosecution shall be instituted against said person." (19). Cheese — full cream, not less than 32 per cent butter fat. Three fourth cream not less than 24 per cent butterfat. One-half cream not less than 16 per cent butter fat. One-fourth cream not less than S per cent butter fat. Skimmed — less than 8 per cent butter fat. ^20). Cheese — half skim not less than 25 per cent butter fat, and quarter skim not less than 12 per cent butter fat, in the water-free substance. (21). TTnited States standards followed upon products not specified in State laws. (22). Ice milk (frozen) 2.40 per cent fat and .60 per cent gelatin. 828 Dkfinitions and Standards NOTE S — (Continued) (23). Composition is to be indicated upon the label, in the case of evapo- rated milk. (24). No state standards. Nearly all incorporated municipalities control sale of dairy products by ordinance. (25). Ice cream to contain not less than 20 per cent milk solids, and to weigh not less than 4.75 lbs. pv^r gallon. (26). Plain ice cream to contain not less than 18 per cent of milk solids. Fruit ice cream not less than 15 per cent of milk solids. (27). Ice cream to contain 32.5 per cent total solids. (28). Ice cream to contain not less than 18.00 per cent milk solids. (29) Milk for making butter, cheese and condensed milk may contain 3.0 per cent fat. (30). Ice cream to contain not less than 30 per cent of total solids. (31). Data given not confirmed at original sources. (32). No state standards upon dairy products, excepting oleomargarine. STATISTICS ON MILK AND CREAM REGULATIONS IN CITIES AND TOWNS. In 1916 a committee from the Official Dairy Instructors' Asso- ciation" made a study of the milk and cream regulations in 694 cities and towns in the United States The cities were classified into four groups according to population and studies were made of the various regulations. Some of the information obtained is shown in detail in Table 152 to 172 as follows : TABLE 152. Grouping of Cities and Regulations Available for Study. Number of cities and towns represented in this survey. Number of cities and towns reporting no regula- tions Number of cities and towns from which partial regulations were available Niunber of complete regulations of cities and towns represented POPULATION oo 5o §1 CO. Oo 511 133 42 8 218 5 69 3 234 125 42 8 TOTAL CITIES 694 223 62 409 Composition Regulations 829 TABLE 153. Regulations' Relating to Water. Number of regulations limiting percentage of water Number of regulations not referring to per- centage of water Number of regulations limiting water content of milk to 89.00 per cent 88.51 per cent 88.50 per cent 88.25 per cent 88.00 per cent 87.51 per cent 87.50 per cent 87.05 per cent 87.00 per cent 80.50 per cent 80.00 per cent 8.00 per cent POPtJI/ATION 2o 8° 79 155 1 3 2 44 1 12 12 1 2 1 11 2 29 2 4 1 3 1 21 21 1 2 1 12 3 2 TOTAL aTIES 160 249 2 11 7 5 89 3 20 1 17 1 3 1 TABLE 154. Regulations Relating to Total Solids. minimum Number of regulations requiring percentage of total solids Number of regulations not referring to per- centage of total solids 106 128 60 65 25 17 198 211 Number of regulations having or calling for 13.00 per cent total solids 12.51 per cent total solids 12.50 per cent total solids 12.15 per cent total solids 12.00 per cent total solids 11.75 per cent total Solids 11.50 per cent total solids 11.00 per cent total solids 10.50 per cent total solids POPULATION em 13 2 15 6 59 2 7 I 1 2 2 1 2 46 2 5 1 3 15 1 3 OS TOTAL orriEs 17 5 20 8 124 5 17 1 1 830 Definitions and Standards TABLE 155. Regulations Relating to Solids Not Fat. POPULATION 11 il 6s TOTAl ciTisa Number of regulations calling for minimum percentage of solids not fat Number of regulations not referring to per- centage of solids not fat Number of regulations calling for 10.50 per cent solids not fat 9.50 per cent solids not fat 9.25 per cent solids not fat 9.00 per cent solids not fat 8.75 per cent solids not fat 8.50 per cent solids not fat 8.25 per cent solids not fat 8.00 per cent solids not fat 38 24 16 1 198 103 26 7 1 1 1 1 6 2 1 1 2 4 28 14 11 1 1 2 2 79 334 1 2 1 9 7 54 1 4 TABLE 156. Regulations Relating to Fat in Milk. Number of regulations requiring a minimum percentage of fat Number of regulations not referring to percent- age of fat Number of regulations calling for 4.00 per cent fat 3.70 per cent fat 3.60 per cent fat 3 51 per cent fat 3.50 per cent fat 3.40 per cent fat 3.35 per cent fat IN umber ol regulations calling for 3.30 per cent fat 3.25 per cent fat 3.20 per cent fat 3.00 per cent fat 2.50 per cent fat 137 97 2 2 35 3 20 67 81 44 1 1 10 1 2 1 19 2 43 1 32 10 1 1 1 7 1 6 2 12 1 257 152 1 2 4 2 53 5 10 1 46 4 127 2 Bacteria Regulations 831 TABLE 157. Regulations Relating to Bacteria in Milk Number of regulations having a legal limit for bacteria in milk Number of regulations not referring to bacterial limits Number of regulations having a numerical limit for bacteria of 50,000 per cubic centimeter 100,000 per cubic centimeter 150,000 per cubic centimeter 200,000 per cubic centimeter 250,000 per cubic centimeter 300,000 per cubic centimeter 350,000 per cubic centimeter POPULATION 5g o si oo 8^ o II 95 66 24 4 139 59 IS 4 1 1 21 11 3 1 3 1 6 7 4 7 4 2 7 10 2 TOTAL CITIES 189 220 2 35 5 17 13 19 TABLE 158. Regulations Relating to Fat in Cream. Number of regulations requiring a minimum percentage of fat Number of regulations not referring to percent age of fat Number of regulations calling for 25.0 per cent fat 22.0 per cent fat. 20.0 per cent fat. 19.0 per cent fat. 18.0 per cent fat. 17.5 per cent fat. 16.0 per cent fat. 15.0 per cent fat. 14.0 per cent fat. 10.0 per cent fat. 87 49 20 5 147 76 22 3 3 1 1 13 3 5 1 42 29 12 2 1 10 6 3 13 10 3 2 1 161 248 4 1 21 1 85 1 19 26 2 1 TABLE 169. Regulations Relating to Tuberculin Test. Number of regulations specifying that cows Be tuberculin tested Be tested once a year Be tested once in two years Be tested twice a year Be tested at discretion of inspector. . . . POPULATION O^ S^ o || 8= oo gg 53 21 21 3 20 16 14 2 1 1 1 TOTAL CTTIK8 98 50 3 1 1 832 Definitions and Standards TABLE 160. Regulations Relating to Bacteria in Cream. Number of regulations having a numerical limit for bacteria of: 400,000 per cubic centimeter 500,000 per cubic centimeter 1,000,000 per cubic centimeter 5,000,000 per cubic centimeter Number of regulations having a legal limit for bacteria in cream Number of regulations not referring to bacterial limits in cream Number of regulations having a numerical limit for bacteria of 50,000 per cubic centimeter 100,000 per cubic centimeter 150,000 per cubic centimeter 200,000 per cubic centimeter 250,000 per cubic centimeter 300,000 per cubic centimeter 350,000 per cubic centimeter 500,000 per cubic centimeter 800,000 per cubic centimeter 1,000,000 per cubic centimeter POPULATION s TOlAl .H CITIES i« §8 io oS in>^ 8" 1 1 1 3 49 27 11 2 89 2 2 1 5 1 1 7 15 8 30 227 110 34 8 379 1 1 1 1 1 1 1 1 2 1 2 3 1 1 1 4 5 10 1 1 3 6 1 10 TABLE 161. Regulations Relating to Temperature. POPULATION 2o o 5 2 o Oo TOTAL CITIICS Number of regulations calling for a temperature not higher than 65° F 6 27 1 12 46 1 1 2 19 1 13 36 2 11 2 15 1 5 1 9 63° F 2 60° F 58 58° F 1 56° F 1 65° F 27 50° F 102 45° F 2 4 Specific Gravity Rrgulations 833 TABLE 162. Regulations Relating to Specific Gravity. Number of regulations prescribing a minimum specific gravity Number of regulations requiring a specific gravity of 1030.0 1029.0 10.29 1.030 1.029-1.033 1.029 1.028 1.027 POPULATION s.g 31 2 4 2 1 20 1 1 ii gS TOTAIi cmxs 38 2 4 2 2 3 23 1 1 TABLE 163. Regulations Relating to Water Supply. POPtn,ATlON o^ 2o oS o go li s-g TOTAL CITIES Number of regulations requiring that water supply be Clean 70 23 7 29 54 .0 26 3 14 30 6 1 1 11 4 4 9 12 8 1 1 2 107 Fresh 30 12 Abundant 53 Free from contamination 98 Pure 14 Well chosen 1 Suitable 1 TABLE 164. Regulations Relating to Milkers. Number of regulations requiring that Milker be free from disease Milker be clean Milker wear clean clothes Milker wash hands before milking Milker brush nails before milking Milking be done with clean dry hands Hands be not wet during milking POPULATION 2o 2o gg oo feg 109 54 22 5 78 40 13 61 34 12 1 52 41 16 2 8 4 2 46 22 10 1 12 22 4 TOTAL CITIES 190 131 108 111 14 79 38 834 DliFlNITIONS AND STANDARDS TABLE 165. Conditions Which Render Milk Legally Unsalable. POPULATION o 1} TOTAL CITIES Number of regulations which forbid the sale of milk under conditions stated below Number of regulations which do not mention when milk is unsalable 234 160 67 46 79 115 10 85 36 29 43 39 3 34 12 6 20 8 8 1 2 396 13 2S7 Number of regulations which mention Diseased cows Cows kept in filthy quarters ILS Milk containing visible dirt 82 Cows kept in crowded and unhealthy stable 144 Number of regulations which mention Sediment Sour Sophisticated Mouldy - Decayed ; . Acid plus 2 Garget Abnormal Unnatural Bitter , Decomposed Glucose Garlic Unhealthy Stringy Cabbage Slimy Sugar waste POPULATION o_ Sr. 5„ it oS go m in"^ in'^ o ■" 1 1 1 1 1 2 3 1 6 1 1 3 1 2 1 1 3 1 9 4 2 2 2 2 1 1 TOTAL CITIES 2 1 1 3 3 8 1 3 3 1 1 3 1 13 4 2 3 1 Milk Regulations TABLE 165— Continued. 835 Number of regulations which mention Milk when adulterated When cows are fed distillers' grains. . . When cows are fed swill From cows a certain number of days before calving From cows a certain number of days after calving Foreign substance in milk Putrefactive feeds Feeds unwholesome Feeds impure Milk unclean Cows fed on refuse Cows fed garbage Cows fed wet brewers' grains Cows given contaminated water Cows fed vinegar waste Pus in milk Cows fed beet pulp Cows fed turnips Cows fed starch waste Diseased cows. Insanitary foods Frozen foods Ropy milk Bloody milk Milk above legal limits in bacteria Milk above legal limits in temperature. Improper milk Watered Diluted Silage Unsound Tainted Musty Insects Hairs Flies POPITLATION 2o 5§ o go m Oo 150 77 30 3 59 42 17 7 58 41 14 3 139 86 27 6 138 89 27 6 107 65 28 5 57 38 21 4 73 50 22 47 38 10 23 16 5 41 28 9 2 34 34 13 3 32 22 12 2 19 10 18 3 6 6 6 8 4 1 5 1 2 2 8 4 1 2 1 1 8 6 14 11 4 1 94 18 139 44 2 2 4 3 1 3 1 1 1 1 1 1 1 1 1 1 TOTAL CITIES 260 125 116 258 260 205 120 145 95 44 80 84 68 50 18 13 6 4 12 3 1 1 14 30 112 185 9 1 3 2 1 3 1 1 1 1 836 Definitions and Standards TABLE 166. Regulations in Regard to Parturition. Number of regulations providing for a specific number of days before and after parturition that the milk cannot be used Number of regulations which do not cover this point Number of regulations prohibiting the sale of milk 60 days before parturition 45 days before parturition 42 days before parturition 40 days before parturition 30 days before parturition 21 days before parturition 20 days before parturition 15 days before parturition 14 days before parturition 12 days before parturition 10 days before parturition 8 days before parturition 4 days before parturition Number of regulations prohibiting the sale of milk 21 days after parturition 15 days after parturition 12 days after parturition 10 days after parturition 9 days after parturition 8 days after parturition 7 days after parturition 6 day* after parturition 5 days after parturition 4 days after parturition 3 days after parturition POPULATION 139 95 4 1 19 6 11 89 4 1 4 1 5 7 28 3 4 10 4 72 3 1 89 36 1 1 3 5 7 63 1 1 2 1 1 3 7 12 2 8 3 52 2 27 15 1 3 23 1 3 5 1 2 2 13 TOTAL CITIXS 261 148 4 1 1 1 23 11 21 180 5 1 4 5 1 1 9 17 46 5 5 21 10 140 5 1 Milk House Regulations TABLE 167, Regulations Relating to Milk House. 83; milk Number of regulations requiring that milk houses be Clean Used for no other purpose Have tight sound floor Be well ventilated Be well lighted Be well drained Number of regulations requiring sterilizing equipment in the milk house Number of regulations requiring that house be Well screened ! Provided with suitable racks Provided with cooling tanks Located a certain distance from the stable Number of regulations requiring milk house to be located 100 feet from stable 50 feet from stable 40 feet from stable 25 feet from stable , 20 feet from stable , 15 feet from stable 12 feet from stable Number of regulations requiring milk house to be located 10 feet from stable Away from stable At a distance from stable With an air space between milk house and stable Apart Distance not given Number of regulations requring that Milk house be free from odors No swine be within a stated distance .... No swine be within 100 feet No swine be within 50 feet Swine be "not near" 132 82 46 62 51 36 13 63 5 8 45 1 28 2 1 1 1 52 27 1 26 LATION O ■*^ o p So o§ 22 3 19 3 13 1 11 1 11 1 14 1 2 16 2 6 5 1 11 1 1 1 1 10 2 3 1 5 22 6 7 1 1 TOTAL CITIES 232 150 87 101 87 71 31 125 15 26 71 2 40 2 1 4 7 80 35 1 26 1 838 Definitions and Standards TABLE 167— Continued. POPULATION 5g O) o o§ Number of regulations requiring that milk house Be a separate room Be a distance from privy 300 feet from privy 200 feet from privy 100 feet from privy 75 feet from privy 50 feet from privy 40 feet from privy 25 feet from privy 15 feet from privy 10 feet from privy Away from privy Not near privy Distant Not mentioned 74 48 26 3 56 40 13 1 1 1 2 3 1 1 4 1 1 1 2 2 3 2 3 1 16 18 6 1 21 10 9 TOTAL aTIES 151 110 1 1 6 1 7 2 5 5 1 34 7 21 19 TABLE 168. Regulations Relating to Milk Utensils. POPULATION 2o o So 2"^ O o o TOTAL CITIES Number of regulations requiring that only round cornered utensils be used 6 5 36 30 5 4 15 17 7 7 14 3 1 11 Number of regulations requiring that only 19 Number of regulations requiring that utensils 58 Number of regulations requiring that utensils be well constructed 62 Number of regulations requiring that utensils be clean Washed Scalded Sterilized Used for no other purpose Protected from contamination Number of regulations represented in the above items Number of regulations containing nothing re- garding the cleaning of utenlils 112 71 22 1 94 52 17 2 48 28 14 3 121 73 25 7 56 33 17 3 52 51 16 1 184 114 37 7 11 5 1 206 165 93 226 109 120 342 67 Milk Plant Regulations 839 TABLE 169. Regulations Relating to City Milk Plants. Number of regulations requiring that milk plant shall Be well lighted Be well ventilated Be well screened Be well drained Be properly constructed Be properly equipped Be clean Be free from flies Be free from odors Be free from contamination Have sewer connections Have facilities for cleaning utensils in plant Have facilities for storing milk in plant. . . . Have running hot and cold water Have separate room for handling milk. . . Have tight walls and ceilings Have tight floors Score a certain number of points Shall score not less than 40 points 50 points 60 points 70 points 75 points not mentioned POPULATION oS 2o si l| TOTAt cmsa 9 8 7 2 26 6 7 6 2 21 10 18 6 1 35 7 8 6 2 23 2 7 5 2 16 8 6 8 22 19 27 19 5 70 5 1 2 2 10 4 1 2 1 8 2 3 1 2 8 2 3 2 7 2 5 5 3 15 3 2 2 7 2 5 1 1 9 4 2 5 1 12 2 5 6 1 14 9 7 7 2 25 5 5 3 13 1 1 1 1 2 1 1 2 2 2 1 5 1 1 2 2 TABLE 170. Regulations Relating to Delivery Wagons. POPULATION li- o o o oS no 53 14 42 30 12 1 88 52 15 3 61 41 14 112 78 23 4 123 74 29 6 TOTAL aTIBS Number of regulations requiring Drivers to be free from disease Wagons to be covered Wagons to be clean Wagons not to haul refuse or be used for any other purpose Name of dealer to appear on wagon. . . Number of license to appear on wagon 177 85 158 116 217 232 840 DEFINITIONS AND STANDARDS TABLE 171. Regulations Relating to the Milk. POPULATION -g e©- TOTAL CITIES Number of regulations requiring that Milk be removed immediately from barn.. Milk be cooled immediately Milk be aerated Fore milk be discarded Milk must not be strained in barn Milk must be stored only in milk house. . . Milk be milked into covered pails Milk be graded 89 89 23 4 4 9 20 45 61 11 6 4 33 14 5 17 18 6 6 2 6 154 171 40 17 11 48 44 9 TABLE 172. Regulations Relating to the Scoiing of Dahy Faims. POPTTLATION -So i| U5 5o O o §1 Oo >5- oS TOTAL CITIES Minimum score of dairy farms 80 2 1 2 8 3 3 6 1 1 12 2 1 2 4 1 3 1 1 1 1 3 75 1 65 , 4 60 23 55 4 50 4 46 -. 1 45 6 40 10 Not given 1 GRADING MILK AND CREAM. The old system of purchasing milk and cream by weight or measure with little attention being given to quality has been largely displaced in recent years by the adoption of methods which insure a higher price to the producer for rich milk or cream and for milk or cream of high sanitary quality. In order to apply this principle to the purchase of milk for the New York City supply the Board of Health of that city established different grades for both milk and cream and formulated regulations gov- erning distribution. Milk and Cream Regulations 841 These regulations are given in detail as follows : "Regulations of the Department of Health of the City of New York Relative to the Grading of Milk and Cream. — Sec. 156. Milk and cream ; grades and designations, — All milk or cream held, kept, offered for sale, sold, or delivered in the City of New York shall be so held, kept, offered for sale, sold or delivered in accordance with the Regulations of the Board of Health and under any of the following grades or designations and not other- wise : ' ' Grade A : For Infants and Children. ' ' 1, Milk or cream (raw). 2. Milk or cream (pasteurized). "Grade B: For Adults." 1, Milk or cream (pasteurized). "Grade C. : For Cooking and Manufacturing Purposes Only." 1, Milk or cream not conforming to the require- ments of any of the subdivisions of Grade A or Grade B, and which has been pasteurized ac- cording to the Regulations of the Board of Health or boiled for at least two (2) minutes. 2. Condensed skimmed milk. The provisions of this section shall apply to milk or cream used for the purpose of producing or used in preparation of sour milk, buttermilk, homogenized milk, milk curds, sour cream, Smeteny, Kumyss, Matzoon, Zoolak, and other similar products or preparations, provided that any such product or preparation be held, kept, offered for sale, sold, or delivered in the City of New York. "Regulations Governing the Sale of Grade 'A' Milk or Cream (Raw). — Definition. — Grade 'A' milk or cream (raw) is milk or cream produced and handled in accordance with the Regulations as herein set forth. "Regulation 113. Tuberculin test and physical condition. — Only such animals shall be admitted to the herd as are in good physical condition, as shown by a thorough physical examination accompanied by a test with the diagnostic injection of tuberculin, within a period of one month previous to such admission. The test ^42 DEFINITIONS AND STANDARDS is to be carried out as prescribed in the Regulations of the Depart- ment of Health governing the tuberculin testing of cattle. A chart recording the result of the official test must be in the possession of the Department of Health before the admission of any animal to the herd. "Regulation 114. Bacterial contents.— Grade 'A' milk (raw) shall not contain more than 60,000 bacteria per c. c. and cream more than 300,000 bacteria per c. c. when delivered to the consumer or at any time prior to such delivery. "Regulation 115. Scoring of dairies. — All dairies producing milk of this designation shall score at least 25 points on equip- ment and 50 points on methods, or a total score of 75 points on an official dairy score card approved by the Department of Health. "Regulation 116. Time of delivery. — Milk of this designation shall'be delivered to the consumer within 36 hours after produc- tion. Regulation 117. Bottling. — Milk or cream of this designation shall be delivered to the consumer only in bottles, unless other- wise specified in the permit. "Regulation 118. Labeling. — The caps of all bottles contain- ing Grade 'A' milk or cream (raw) shall be white, with the grade and designation 'Grade A (raw)' the name and address of the dealer, and the word 'certified' when authorized by the state law, clearly, legibly, and conspicuously displayed on the outer side thereof. No other word, statement, design, mark, or device shall appear on that part of the outer cap containing the grade and the designation unless authorized and permitted by the Department of Health. A proof print or sketch of such cap, showing the size and arrangement of the lettering thereon, shall be submitted to and approved by the said Department before being attached to any bottle containing milk or cream of the said grade and designation. "Additional Regulations Governing- the Sale of Grade 'A' Milk or Cream (Pasteurized). Definition. — Grade 'A' milk or cream (pasteurized) is milk or cream handled and sold by dealers holding permits therefor from the Board of Health, and produced and handled in accordance with the Regulations as herein set forth. Milk and Cream Rfx.uIvATions 843 ''Regulation 119. Physical exainiuation of cows. — All cows producing milk or cream of this designation must be healthy, as determined by a physical examination made annually by a duly licensed veterinarian. "Eegulation 120. Bacterial content. — Milk of this designation shall not contain more than 30,000 bacteria per c. c. and cream more than 150,000 bacteria per c. c. when delivered to the con- sumer or at any time after pasteurization and prior to such de- livery. No milk supply averaging more than 200,000 bacteria per c. c. shall be pasteurized to be sold under this designation. "Regulation 121. Scoring of dairies. — All dairies producing milk or cream of this designation shall score at least 25 points on equipment and 43 points on methods, or a total score of 68 points on an official score card approved by the Department of Health. "Regulation 122. Times of delivery. — Milk or cream of this designation shall be delivered within 36 hours after pasteuriza- tion. "Regulation 123. Bottling. — Milk or cream of this designa- tion shall be delivered to the consumer only in bottles unless otherwise specified. Regulation 124, Bottles only. — The caps of all bottles contain- ing Grade 'A' milk or cream (pasteurized) shall be white with the grade and designation 'Grade A (pasteurized),' the name and address of the dealer, the date and hours between which pas- teurization was completed, and the place where pasteurization was performed, clearly, legibly, and conspicuously displayed on the outer side thereof. No other word, statement, design, mark, or device shall appear on that part of the outer cap containing the grade and designation, unless authorized and permitted by the Department of Health. A proof print or sketch of such cap, sliowing the size and arrangement of the lettering thereon, shall be submitted to and approved by the said Department before being attachd to the bottles containing milk of the said grade and designation. No other words, statement, design or device shall appear upon the outer cap unless approved by the Department of Health. The size and arrangement of lettering on such cap must be approved by the Department of Health. "Regulation 125. Pasteurization. — Only such milk or cream shall be regarded as pasteurized as has been subjected to a tem- 844 Definitions and Standards peratiire of from 142 to 145 degrees F. for not less than thirty minutes. "Additional Regulations Governing the Sale of Grade 'B' Milk or Cream (Pasteurized). Definition. — Grade 'B' milk or cream (pasteurized) is milk or cream produced and handled in accord- ance with the minimum requirements of the Regulations herein set forth and which has been pasteurized in accordance with the Regulations of the Department of Health for pasteurization. "Regulation 128. Physical examination of cows. — All cows producing milk or cream of this designation must be healthy as determined by a physical examination made and approved by a duly licensed veterinarian. "Regulation 129. Bacterial contents. — No milk under this designation shall contain more than 100,000 bacteria per c. c. and no cream shall contain more than 500,000 bacteria per c. c. when delivered to the consumer, or at 'any time after pasteurization and prior to such delivery. No milk supply averaging more than 1,500,000 bacteria per c. c. shall be pasteurized in this city under this designation. No milk supply averaging more than 300,000 bacteria per c. c. shall be pasteurized outside the City of New York to be sold in said city under this designation. "Regulation 130. Scoring of dairies. — Dairies producing milk or cream of this designation shall score at least 20 points on equipment and 35 points on methods, or a total score of 55 points on an official score card approved by the Department of Health. "Regulation 131. Time of delivery. — Milk of this designation shall be delivered Avithin 36 hours. Cream shall be delivered with- in seventy-two (72) hours after pasteurization. Cream intended for manufacturing purposes may be stored in cold storage and held thereat in bulk at a temperature not higher than 32 degrees F. for a period conforming with the laws of the state of New York. Such cream shall be delivered in containers, other than bottles, within twenty-four (24) hours after removal from cold storage and shall be used only in the manufacture of products in which cooking is required. "Regulation 132. Bottling. — Milk of this designation may be delivered in cans or bottles. Milk and Crkam Regulations 845 "Regulation 133 — Labeling. — The caps of all bottles contain- ing Grade 'B' milk (pasteurized) and the tags attached to all cans containing Grade 'B' milk or cream (pasteurized) shall be white with the grade and designation 'Grade B (pasteurized),' the name and address of the dealer, and the date when and place where pasteurization was performed, clearly, legibl}^, and conspicuously displayed on the outer side thereof. The caps of all bottles con- taining Grade 'B' cream (pasteurized) shall be white with the grade and designation 'Grade B Cream (pasteurized),' the name and address of the dealer, and the date when and the place where bottled, clearly, legibly, and conspicuously displayed on the outer side thereof. No other word, statement, design, mark, or device shall appear on that part of the outer cap or tag containing the grade and designation unless authorized and permitted by the Department of Health. A proof print or sketch of such cap or tag, showing the size and arrangement of the lettering thereon shall be submitted to and approved by the said Department before being attached to any receptacle containing milk or cream of the said grade and designation. "Regulation 134. Pasteurization. — Only such milk or cream shall be regarded as pasteurized as has been subjected to a tem- perature of from 142 to 145 degrees F. for not less than thirty minutes. "Additional Regulations Groverning the Sale of Grade 'C Milk or Cream (Pasteurized) (for Cooking and Manufacturing- Purposes Only). Definition. — Grade 'C milk or cream is milk or cream not conforming to the requirements of any of the sub- divisions of Grade 'A' or Grade 'B' and which has been pas- teurized according to the Regulations of the Board of Health or boiled for at l^ast two minutes. "Regulation 136. Physical examination of cows. — All cows producing milk or cream of this designation must be healthy as determined by a physical examination made by a duly licensed veterinarian. "Regulation 137. Bacterial content. — No milk of this designa- tion shall contain more than 300,000 bacteria per c. c. and no cream of this grade shall contain more than 1,500,000 bacteria per c. c. after pasteurization. 846 Definitions and Standards "Regulation 138. Scoring of dairies. — Dairies producing milk or cream of this designation must score at least 40 points on an official score card approved by the Department of Health. "Regulation 139. Time of delivery. — Milk or cream of this designation shall be delivered within 48 hours after pasteuriza- tion. "Regulation 140. Bottling. — Milk or cream of this desig- nation shall be delivered in cans only. "Regulation 141. Labeling. — The tags attached to all cans con- taining Grade 'C milk (for cooking) shall be white with the grade and designation 'Grade C Milk (for cooking),' the name and address of the dealer, and the date when and place where pasteurization was performed, clearly, legibly, and conspicuously displayed thereon. No other word, statement, design, mark, or device shall appear on that part of the tag containing the grade and designation, unless authorized and permitted by the Depart- ment of Health. A proof print or sketch of such tag, showing the size and arrangement of the lettering thereon shall be sub- mitted to and approved by the said Department before being at- tached to the cans containing milk of the said grade and designa- tion. The cans shall have properly sealed metal covers painted red, "Regulation 142. Pasteurization. — Only such milk or cream shall be regarded as pasteurized as has been subjected to a tem- perature of 145 degrees, for not less than thirty minutes. "Additional Regulations Governing- the Sale of Condensed Skim-Milk. Definition. — Condensed skimmed milk is condensed milk in which the butter- fat is less than twenty-five (25) per cent of the total milk solids. "Regulation 145. Cans to be painted blue. — The cans contain- ing condensed skimmed milk shall be colored a bright blue and shall bear the words "Condensed Skimmed Milk" in block letters at least two inches high and two inches wide, with a space of at least one-half inch between any two letters. The milk shall be delivered to the person to whom sold, in can or cans, as required in this regulation, excepting when sold in hermetically sealed cans. Mii^K AND Cream Regulations 847 "Additional Regulations Governing the Labeling of Milk or Cream Brought Into, Delivered, Offered for Sale, and Sold in New York City. Regulation 146. Labeling of milk or cream. — Each container or receptacle used for bringing milk or cream into or delivering it in the City of New York shall bear a tag or label stating, if shipped from a creamery or dairy, the location of the said creamery or dairy, the date of shipment, the name of the dealer, and the grade of the product contained therein, except as elsewhere provided for delivery of cream in bottles. "Regulation 147. Labeling of milk or cream to be pasteur- ized. — All milk or cream brought into the City of New York to be pasteurized shall have a tag affixed to each and every can or other receptacle indicating the place of shipment, date of ship- ment, and the words 'to be pasteurized at (stating location of pasteurizing plants).' "Regulation 148. Mislabeling of milk or cream. — Milk or cream of one grade or designation shall not be held, kept, offered for sale, sold, or labeled as milk or cream of a higher grade or desig- nation. "Regulation 149. Word, statement, design, mark or device on label.— No word, statement, design, mark, or device regarding the milk or cream shall appear on any cap or tag attached to any bottle, can, or other receptacles containing milk or cream Avhich words, statement, design, mark, or device is false or misleading in any particular. "Regulation 150. Tags to be saved. — As soon as the contents of such container or receptacle are sold, or before the said con- tainer is returned or otherwise disposed of, or leaves the pos- session of the dealer, the tag thereon shall be removed and kept on file in the store, where such milk or cream has been sold, for a period of two months thereafter, for inspection by the Depart- ment of Health. "Regulation 151. Record of milk or cream delivered. — Every wholesale dealer in the city of New York shall keep a record in his main office in the said city, which shall show from which place or places milk or cream, delivered by him daily to retail stores in the city of New York, has been received and to whom delivered, 848 Definitions and Standards and the said record shall be kept for a period of two months, for inspection by the Department of Health, and shall be readily ac- cessible to the inspectors of the said Department at all times." REFERENCES. ^Circular 136, U. S. Department of Agriculture. -Taylor, Geo. B. and Thomas, Harry N. Mimeographed circular, Legal Standards for Dairy Products. ''Report of the committee of Statistics of the milk and cream. Regula- tions of the Official Dairy Instructions Ass'n. Jour. Dairy Science Vol. 1 No. 1, 1917. CHAPTER XXII MISCELLANEOUS INFORMATION REGARDING DAIRY PRODUCTS Flow Sheets of Various Dairy Products. — Figs. 176 to 191 indi- cate the various steps commonly taken in the handling of all the common dairy products, under the American methods of manu- facture now in general use. They represent the line or the lines of flow of the several products while going through the plant, and make it possible readily to visualize the various operations involved. VACUUM PAN dOlNDLNSLD WHOLE. MILK I H0M0GLN12E.R COOLLR I FILLER STERILIZER —1 EVAPORATED MILK WHOLE MILK CANL SUGAR VACUUM PAN I COOLER SWEETENED COND. WHOLE I GELATIN I SEPARATOR ICREAMh RIPENER CHljRN |butte.r| IsuttermilkI vacuum pan I CONDENSED BUTTERMILK VACUUM PAN I MOMOGENIZER I COOLER [gelatin! SKIM MILK VACUUM PAN COND SKIM MILK CANE 5UGAR VACUUM PAN _1_ SWEET. CON P. SKlM-MlLK ICECREAM MIX PASTEURIZER I H0M0GEN12ER I COOLER \ METHOD 1 ICECREAM MIX METHOD Z Tig. 176. General Flow Sheet of Milk. [849] /850 MlSCKlwLANEOUS InT'ORMATION o q lU "1 ,, tt; r "J ■J.IHi.W QIXIW -39 01 iOM •iNiod 9IWX woaj z 3avy!) ^u; b O SS o o q 2 1 5 < < o o ■11 HUM alXlW 39 ION XVW ^O MIM INIOd <;IH1 WOMJ z lavyD 9v iwvs ai?53Poyd i lavyo O uJ Q Q i^ H O > O 1- I ^ ^ ^ O 0. ^ J? h- u Q uJ < 3b^ P uJ If) o a o o u o uJ N or 5 ^ D o O > UJ X uJ ■uJ- -^- "s: U ^1 1 aJ < fk 5 ^ z aJ < O to ? ^ ^ £ Q^ uJ "- 3 N t^ tkr d D-b_- UJ "- ".O Lt p ^ ,^ H 0- h z: z: < n-g- g z: >- 8 uJ I- ft^ 3 £D H uJ ^ <0 _e) s uJ «0 o 2 ^ '^ O h- 3 o - U/_Q "^ uJ o > ^ z %3 .4 h; o "J fe •^ f^ fk: I uJ O S Fi.ow Sheets 851 -i-t'-2?-o-^-^-g-^-^-B---!o- ■fe P !4 . « 0) * d ^ S M ^ <« SI a> - -4^ >-" 5 UK => 1/) ui a ,, iir k O uJ < S -I "J P -S -I u. I r Q 5 S tt^ •n '" "^ 5 ^ z 0. t! ^ Q "^ uJ O J i UJ Ifl $ O o I J z H • o 5 0) rt to g o M uJ U5 O N r £ 1^ u P ^o n <"o-^-5-j-a-d O IJ $ g S Q- O z h Z a. 0. o 2 < p O D O " >» 'rt uj 1- 1/3 X OS Z S ¥ ^50 ^|-iJ-S|-|-o-|-Q-5- O yn 3 uJ < uJ UJ V Q ? 05 - J- 0- "- ft s 2 ■ 0. 0- -o-f cfl <" S ^ g t z ^- < ■<-o-o: •-"If -j ij in o- O H O l" T Z c/) K "O F) .!4 • :i u n ^ *> 2 4) ri n r^S uJY 5? ^^ 0^ 852 MiSCELLANKOUS INFORMATION t; Q UJ l" 5 g -Q_0- .£.H_-_5_«-S- W] < z *r -J o i [^ UJ h t' t- -1 m fr ^■) =3 Lij o "^ " U) < U ^ ^ 0. 5 s §1 < o .3 (« itr U.' 5 < Q " ci X g Q D >« Z ^ ^ r °cO Q tc ^ Sk o =■ = <; O CD r?-2- 1- u 5 < v> o (C < uJ S 5 3 I o ^ >/) S *- I r U1 o or z >o Uj O ? ? 1 2 < -i-8-i- Its o ^ O g 5] < uJ III O - 2 ""o — 2' o ■ ui r o o or -■- ^ ^ ^ ^ a '$ i \^ -, o t § ^ I >l o o O uj UJ <; O 1- < < .J J 1- 1- X or K h — 1 UJ o o >- UJ < O > 0- IJ > r\ 5 «5 (8 Fi,ow Sheets 853 uJ uJ a r z *" < i* _i o I- "^ _l vS uJ P uJ ~ _J t ^ o D. Z > H N q; uJ-^-S-O-f- -h-Q-D' - X r 2 „. a. I t o O K I- I o o (0 S 1 . 'J is H ^ 2 to -s-i3-|-9i-^-':'- •'iboz oo-tJ* 11 1 2 uJ uJ .^- o § q: ^ ":_(t_o._, Q O S UJ *JJ irt a- S UJ X UJ aJ I- (to: :i _i 2r Q- Q W3 Ci £ = rs Q £ <=' Q V " - S CC t DC ^, X ? :3 :3 3 o o o o < UJ *" UJ liJ r I z ui 5 ;— ft •* h « 854 Miscellaneous Information Temperature 855 TEMPERATURES FOR HOLDING, MANUFACTURING AND STORING DAIRY PRODUCTS. Ill the handling of dairy products, there is probably no one single factor that influences the quality and the commercial value of the product, so much as temperature. Table 173 lists the temperatures that in good practice give the best results under the various conditions named. TABLE 173. Temperatures for Holding, Manufacturing and Storing Dairy Products. Name of Product. Fluid milk and skim-milk to be held under 12 hours after milking, not pasteurized Fluid milk and skim-milk to be held under 24 hours after milking, not pasteurized Fluid milk and skim-milk to be held under 48 hours after milking, not pasteurized Fluid milk or skim-milk, pasteurized, to be held 24 hours or less Fluid milk or skim-milk, pasteurized, to be held up to 6 days Fluid milk heated to pasteurizing temperatures and held without cooling up to 6 hours Cream not pasteurized, to be held 24 hours or less nuid milk and cream pasteurizing temperatures Cream pasteurized, to be held up to 10 days Cream pasteurized, to be frozen and held up to 3 montlis . . Wliey not pasteurized, to be held 6 hours or less Cultured buttermilk, pasteurizing temperature before inoculating Cultured buttermilk, lactic type, inoculating temperature . Cultured buttermilk lactic type, incubating temperature . . Cultured buttermilk, Bulgaricus type, inoculating tempera- ture Cultured biittermilk, Bulgaricus type, incubating tempera- ture Cultured buttermilk, either tyi)e, liolding temperature.... Buttermilk cultures, either lactic or Bulgaricus type. Hold- ing temperature Ice cream mix to be held for .'24 to 96 hours Ice cream hardening and holding Evaporated milk hot well temperatures Evaporated milk, temperature in vacuum pan Evaporated milk before processing. When canned imme- diately after condensing Evaporated milk before processing. When canned 24 hours after condensing Evaporated milk before processing. When canned 48 liours after condensing Temp, o F. recommended 50 or below 40 34 40 34 142 to 40 145 140 to 34 25 50 145 170 to 68 68 98 98 190 45 to 50 In water 35 32 to 40 to 5 160 to 212 125 to 60 42 40 140 856 Miscellaneous Information TABLE 173 (Continued). Evaporated milk after processing. When held before pack- ing to develop leakers Evaporated milk after processing. If consumed within two months after manufacture Evaporated milk after processing. \\'heii held in storage for one year or less Sweetened condensed milk, hot well temperatures Sweetened condensed milk, pan temperatures Sweetened condensed milk. Temperature at which to bar- rel or can Sweetened condensed milk. When held for early consump- tion Sweetened condensed milk. When held in storage for one year or less Bulk imsweetened condensed milk. For consumption inside of one week Butter churning temperatures, Simimer Average about 56° F. Winter Where cotton seed meal is fed and under certain feed and breed conditions higher churning temperatures may be used. Butter in cold storage Cheese, best temperature for action of rennet in making Cheddar cheese Clieese, high curing temperature, cheddar cheese Cheese, low curing temperature, cheddar cheese Cheese in storage Temperature at which milk powder can be heated during manufacture without impairing flavor Milk powder in storage 68 Ordinary temperature 35 to 40 160 to 212 125 to 140 About 74 Ordinary temperature .35 to 40 40 48 to 53 52 to 60 -10 86 to 88 60 to 68 45 to 35 140 50 35 to 40 THE ACTION OF MILK UPON METALS AND CERTAIN PROPER- TIES OF METALS AND ALLOYS. The action of milk upon various metals as well as upon other products used in its handling is of importance in several respects. The principal factors of interest are the influence of the metals upon the flavor of the milk or products derived from it ; life and cost of the equipment made from various metals ; properties that afi^ect the appearance of the equipment ; the ease or the difficulty with which the various metals are kept in a clean, and sanitary condition, and heat transmitting qualities of the various metals. Relatively little published data is available upon the above subjects. Erf made a considerable study of the influence of various metals upon the flavor of milk. "A solution of dilute lactic acid mixed with citric acid charged slightly with carbon dioxide was first used, as it was very difficult to obtain any re- Action of Milk on Metals 857 action from the small quantities of metal actually dissolved. Then we continued to dilute this with milk, and noted the effect upon the flavor." pifif. 192. Parts Per MiUion of MetaUic Lactates required to Impart a Definite Taste to Water. Based Upon Donauer's Results. The order of solubilities of the various metals was as follows : wrought iron, east iron, steel, brass, lead, copper and tin. "As nearly as we could calculate about one millionth part of copper would give a decided flavor to the milk. The amount of flavor given by the tin was very small." Careful tests were made in the Research Laboratories of Mojonnier Bros. Co.- and the results obtained will be given in this chapter. 858 Miscellaneous Information The best work reported upon the subject is by Donauer of the Research Laboratories of the Elyria Enamelled Products Co.^ Fig. 192 shows the amount in parts per million in water of the various metallic lactates which according to Donauer are required to impart a definite taste to water. No exact data is yet available to indicate the amount of metallic lactates that are required to impart a metallic flavor to milk, or to products de- rived from milk. It is well known that many or probably all of the metallic salts combine readily with the casein in milk, forming insoluble compounds whose properties and reactions are not well understood. It is not established if there is any chemical reaction between metallic salts and butter fat or other con- stituents of the milk besides the casein. The evidence at the present time is that a different result should be obtained when the metallic lactates are added to milk, as against when added in equal amounts to water. On account of the compounds formed by metallic salts in milk, probably a larger quantity would be re- quired to impart a metallic flavor to milk than to water. The solubility of metals in milk is influenced by the tempera- tures used; by the time of contact of the metal with the milk, and by the acid content of the milk. The results reported by Donauer in the case of whole milk are given under Table 174 for temperatures at 64 and 149° F. TABLE 174. Influence of Temperature Upon the Solubility of Metals m Milk Based Upon Donauet's Results. Whole Milk Testing .26 Per Cent Lactic Acid. Loss in weight in mg. per sq. cm. per 24 hours Temperature of Experiment Alum- inum Bronze Alum- inum White Metal Alloy Brass Bronze Copper German Silver Monel Metal "F. °C. 64 18 149 65 .015 .250 .0195 .57 .01 .08 .095 .06 .09 .055 .07 .04 .05 .08 .045 .07 Loss in weight in mg. per sq. cm. per 24 hours Temperature of Experiment Nickel Nickel Iron Alloy Tin Iron Steel Alloy No. 1 Steel Alloy No. 2 Zinc °F. °C. 64 18 149 65 .095 .09 .011 .15 .0125 .15 .041 1.71 .015 .34 .014 .25 .0575 2.18 Action oi^ Milk on Metals 859 The results in Table 174 show that in the case of whole milk testing .26 per cent lactic acid more of the metals pass into solu- tion at pasteurizing temperatures than at room temperature. Liedel obtained similar results in the case of copper in fresh whole milk testing .18 per cent acid as follows : — At 65°F. for 24 hours, .024 mg. dissolved per sq. cm. At 140° F. for 7 hours, .071 mg. dissolved per sq. cm. Pig-. 193. The Influence of the Acid Content of Milk Upon the SolubUity of Metals. Based Upon Donauer's Results. At 140° F., Liedel- obtained a solubility of .020 mg. per sq. cm., at the end of one hour, and .071 mg. per sq. cm., at the end of seven hours in the case of whole milk. The rate of solution 860 Miscellaneous Information is probably much larger during the first hour of contact than during succeeding periods. This may be due to the formation of a film or coating of milk solids over the metals, or to the presence of a more readily soluble coating of an oxide of the metal upon its surface before placing the metal in the milk. The influence of the acidity of the milk upon the solubility of the metals is shown in Fig. 193 which is based upon Donauer's results. The results obtained show a slight difference in the action, being in the majority of cases slightly higher in the case of sour milk. Relation of Metallic Taste to Quantity of Metal Dissolved.— A careful comparison is presented herewith of the relation between the amounts of metallic lactates reported by Donauer as being required to impart a metallic taste to water, and the quantity of metals that were found to pass into solution in fresh whole milk. It is assumed that the rate of solution during the first hour is equal to 25 per cent of the total amount that passed into solution in 24 hours. The method of calculation used by Donauer* throughout the comparisons, is given as follows: "Cal- culations concerning the pasteurizer were based on an average standard 500 gallon vat with rotating coil, the heating surface being approximately 20 sq. in. per gallon." In the methods in general use the world over for handling milk and its products it is seldom that the heat treatment exceeds one hour at 140° F. The values given in Table 175 are therefore conservative, and in practice the quantities of metal dissolved, are probably less than those given, under the conditions named. Copper, tin, brass and German silver were found to dissolve in smaller quantities than are necessary to impart a metallic flavor. Iron and aluminum dissolved in excess of the amount required to impart a metallic flavor. The above named results are confirmed by practical experience covering many years and in various branches of the dairy in- dustry. Equipment, used in the manufacture of dairy products, made either of pure copper or of tinned copper is known to have given many years of daily service without showing appreciable wear, other than the mechanical wear caused by daily cleaning. Action of Milk on MiiTALS 861 u ■a 1^ n pq < 4> H m ft H w 04 (S 01 •2 o « o o fl o o 53 a « o'SSi f^Hf^J^l -? (t — 3 — 53 I ^ « « m t. 3 -3 03 S-T3 o-S 5 • — ^^ « B* rt S o o b3^45-a ^-IPh 'Kfo ^a G°s o fe^ go « t;=; oj cj 3 c9 „:& ^gg-S o 10 CO «0 CO ^ -^ Tt* I I + + + + -H 00 CO C^l (M lO -^ C^ Cq 00 ^ .^ CO ■^ ■^ (SS' 862 Miscellaneous Information Hess^ reports one experiment in which milk was pasteurized for 30 minutes at 145° F. in a copper vessel, and upon feeding this milk to guinea pigs the animals developed scurvy. A portion of the same lot of milk pasteurized in a glass vessel and fed to guinea pigs did not produce scurvy. Contrary to this result may he cited the case of condensed buttermilk which has assumed comparatively large commercial proportions. This product is manufactured entirely in copper vacuum pans, and its content of lactic acid would produce maximum action upon the copper of any of the common dairy product, yet it is recognized as being able to stimulate growth in poultry and hogs to a remarkable degree. No experiments are known to have been made regarding its content of antiscorbutic vitamine. The life and the relative cost of the various metals, other con- siderations being equal, is a deciding factor in the selection of the proper metals. Products made of copper have the advantage of retaining a considerable part of their original cost in junk form. Equipment products in certain sizes or shapes can be pro- duced most economically if made in pure copper or in tinned copper. Again, in other cases, nearly every advantage is in favor of glass enamelled equipment, which has numerous characteristic advantages. Aluminum has so far found but scant use in the dairy industry, but it has certain properties that may entitle it to definite use. It is already being used in France for making milk cans and milk bottles. For making containers for milk products that are to be handled cold, it may come into further use. For handling hot milk products, it meets with the objection of its comparative solubility at high temperatures. No exact data is available regarding the influence of vacuum upon the solubility of metals in milk. Likewise the influences of agitation, composition and concentration of the milk products. The Action of Condensed and Evaporated Milk Upon Tin and Iron. — The action of various foods including condensed and evaporated milks upon the solubility of tin and iron in tin cans was made the subject of a very comprehensive study under the general direction of the research committee of the National Can- ners Association.' In the case of condensed milk they found "that the amount of tin and iron increased slightly during storage, but the increase Heat Transmission of Me;tai,s 863 had little significance, as the total amounts were very small. The tin varied from five to 22 milligrams, and the iron from two to 10 milligrams per kilograms of product." In the case of evaporated milk, ''the average tin content varied from 60 to 106 milligrams per kilogram of milk, which was considerably higher than with condensed milk. There was a slight but definite increase in tin and iron with storage. Differ- ences in coating had no effect upon the solution of tin and iron." THE HEAT TRANSMISSION OF METALS AND ALLOYS. The ease with which heat can be transmitted through various metals is a factor of great practical and commercial importance, in aiming at the proper choice. This is the factor that influences most of all the time element in the handling of dairy products. Table 176 gives the conductivity of the more common metals and alloys. TABLE 176. Conductivity for Heat of Certain Metals, Alloys and Glass. Temp. ° Conductivity f for Heat Coefficient K Substance Temp. " Conductivity Substance C F C F for Heat 1 J Coefficient K 18 64 .480 Nickel 18 64 .142 100 212 .492 Nickel 100 212 .138 Brass 17 63 .260 Platinum 18 64 .166 Brass, yellow 32 .204 Platinum 100 212 .173 32 .246 Silver 18 64 1.006 Copper 18 64 .918 Silver 100 212 .992 100 212 .908 Tin 32 .155 32 .070 Tin 100 212 .145 Gold 17 63 .705 Zinc 18 64 .265 Iron, pure 18 64 .161 100 212 .262 Iron, pure 100 212 .151 Glass 32 .0028 Iron, steel 18 64 .108 Iron, steel 100 212 .107 Lead 18 64 .083 Lead 100 212 .081 864 Definitions and Standards The coefficient K is the quantity of heat in small calories which is transmitted per second through a plate one centimeter thick per square centimeter of its surface, when the difference of temperature between the two faces of the plate is one degree centigrade.^ The figures in Table 176 show that next to silver, copper is the best conductor of heat known, and it is one of the best reasons for the strong position of copper in the dairy industry. The knowledge of the relation of milk and its products to various metals is incomplete in many particulars, and exact data is relatively scarce. Much remains to be learned upon these subjects. REFERENCES. 1 Erf, Oscar: Prof, of Dairying Ohio State University, personal letter May 4, 1922. ^ Analytical results all obtained by H. J. Liedel. Research Laboratory Mojonnier Bros. Co., Chicago, 111. 3 Donauer, Max. The action of metals upon Milk. The Ice Cream Review, Milwaukee, Wis., p 78, 1922. 1921, p 115. ■* Donauer, Max; Letter April 14, 1922. = Hess, Alfred F. The antiscorbutic vitamine. Journal Ind. and Eng. Chem. « Smithsonian Physical Tables 1921, p 213. ■^ Relative value of different weights of tin coating on canned food con- tainers. National Canners Ass'n. 1917. 8 Smithsonian Physical Tables. 1921, p 213. APPENDIX TABLE 177. Degiees Twaddell with Corresponding Specific Gravity. Temp.6»-lZ- (3) 60° F. Formula: Degrees Twaddell=(200xSp. Gr.)— 200 Formula: Specific Gravity=^^g^^J^^^^«H:?^ 200 Degrees Specific Degrees Specific Degrees Specific Degrees Specific Degrees Specific Twaddle Gravity Twaddle Gravity Twaddle Gravity Twaddle Gravity Twaddle Gravity 60°/60° F 60° F. 60°/60° F. 60° F 60°/60° F 60° F 60°/60° F 60° F 60°/G0° F 60° F 1.000 40 1.200 80 1.400 120 1.600 160 1.800 1 1.005 41 1.205 81 1.405 121 1.605 161 1.805 2 1.010 42 1.210 82 1.410 122 1.610 162 1.810 8 1.015 43 1.215 83 1.415 123 1.615 163 1.815 4 1.020 44 1.220 84 1.420 124 1.620 164 1,820 5 1.025 45 1.225 85 1.425 125 1.625 165 1.825 G 1.030 46 1.230 86 1.430 126 1.630 166 1.830 7 1.035 47 1.235 87 1.435 127 1.635 167 1.835 8 1.040 48 1.240 88 1.440 128 1.640 168 1.840 9 1.045 49 1.245 89 1.445 129 1.645 169 I 845 10 1.050 50 1.250 90 1.450 130 1.650 170 1.850 U 1.055 51 1.255 91 1.455 131 1.655 171 1.855 12 1.060 52 1.260 92 1.460 132 1.660 172 1.860 13 1.065 53 1.265 93 1.465 133 1.665 173 1.865 14 1.070 54 1.270 94 1.470 134 1.670 174 1.870 15 1.075 55 1.275 95 1.475 135 1.675 175 1.875 16 1.080 56 1.280 96 1.480 136 1.680 176 1.880 17 1.085 57 1.285 97 1.485 137 1.685 177 1.885 18 1.090 58 1.290 98 1.490 138 1.690 178 1.890 19 1.095 59 1.295 99 1.495 139 1.695 179 1.895 20 1.100 60 1.300 100 1.500 140 1.700 180 1.900 21 1.105 61 1.305 101 1.505 141 1.705 22 1.110 62 1.310 102 1.510 142 1.710 23 1.115 63 1.315 103 1.515 143 1.715 24 1.120 64 1.320 104 1.520 144 1.720 25 1.125 65 1.325 105 1.525 145 1.725 26 1.130 66 1.330 106 1.530 146 1.730 27 1.135 67 1.335 107 1.535 147 1.735 28 1.140 68 1.340 108 1.540 148 1.740 29 1.145 69 1.345 109 1.545 149 1.745 SO 1.150 70 1.350 110 1.550 150 1.750 31 1.155 71 1.355 HI 1.555 151 1.755 34 1.160 72 1.360 112 1.560 152 1.760 33 1.165 73 1.365 113 1.565 153 1.765 34 1.170 74 1.370 114 1.570 154 1.770 35 1.175 75 1.375 115 1.575 155 1.775 36 1.180 76 1.380 116 1.580 156 1.780 87 1.185 77 1.385 117 1.585 157 1.785 88 1.190 78 1.390 118 1.590 )58 1.790 39 1.195 79 1.395 119 1.595 159 1.795 [865] 866 Appkndtx CD "c o s§ CO 00 o 950. 30. imes 500. 61.1 78. 70. § d o o o CO CO i d |£°" « t^ CO S cc 1 •" '"' 1 /v o ^ 3 .*J CO 1 c CO > M «i; bD 1^ o l 1 m OS ira CO Meltin Point °C od o 00 o a o - d d !>.■ d to d S I d f— lO O O CO s s oo oo 3 00 c5 § § 1 5> Cs s.a j .9 S 2 ^ oo »o oo CD Tp C5 O 1 3 CN c\ .c 2 J= 1 ■- Zf2 3 3 CC c^ cc o o" r o c .2 a. o o o o o o (J o „ c ^ (, a c> •* § 1 o 5S T o o 1 '3 1 H c Lin Coeff if Exp; _ s S3 S o> ;o o o o CO oc oc CO oo »-< lO •« CO -t -* 1^ X O Oi >o O" CO o ^^ o CO CO o c: o .— c Thermal Con- ductivity il -* o 1 o CO s Electrical Con- ductivity AtO°C ^ ^ ~ c: o cr ^ ~ ~ ^ o ""; g o i o o c g ■^ CO u~ 1 c CM c~ 'J o- oc o ^ ffi c. ** O- c: •* ■ CO en cc CO -^ c ec O C1 O Q ^ "7 ~ cc •p o o 2: ^ o c (X c: lO o E C^ (M oc c^ c^ CO rt 1 H [ I 7 2 oo » o. 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( ir fiO^^ F 1 130+ Baume° 60° F. / Degrees TENTHS OF DEGREES Baume 1 2 3 4 5 6 7 8 9 10 1.0000 .9993 .9986 .9979 .9971 .9964 .9957 .9950 .9943 .9936 11 .9929 .9922 .9915 .9908 .9901 .9894 .9887 .9880 .9873 .9866 12 .9859 .9852 .9845 .9838 .9831 .9824 .9818 .9811 .9804 .9797 13 .9790 .9783 .9776 .9770 .9763 .9756 .9749 .9742 .9736 .9729 14 .9722 .9715 .9709 .9702 .9695 .9688 .9682 .9675 .9668 .9662 15 .9655 .9649 .9642 .9635 .9629 .9622 .9615 .9609 .9602 .9596 16 .9589 .9582 .9576 .9569 .9563 .9556 .9550 .9543 .9537 .9530 17 .9524 .9517 .9511 .9504 .9497 .9491 .9485 .9479 .9472 .9465 18 .9459 .9453 .9447 .9440 .9434 .9428 .9421 .9415 .9408 .9402 19 .9396 .9390 .9383 .9377 .9371 .9365 .9358 .9352 .9346 .9340 20 .9333 .9327 .9321 .9315 .9309 .9302 .9296 .9290 .9284 .9278 21 .9272 .9265 .9259 .9253 .9247 .9241 .9235 .9229 .9223 .9216 22 .9210 92.04 .9198 .9192 .9186 .9180 .9174 .9168 .9162 .9156 23 .9150 .9144 .9138 .9132 .9126 .9120 .9114 .9109 .9103 .9097 24 .9091 .9085 .9079 .9073 .9067 .9061 .9056 .9050 .9044 .9038 25 .9032 .9026 .9021 .9015 .9009 .9003 .8997 .8992 .8986 .8980 26 .8374 .8968 .8963 .8957 .8951 .8946 .8940 .8934 .8929 .8923 27 .^917 .8911 .8906 .8900 .8895 .8889 .8883 .8878 .8872 .8866 28 .8861 .8855 .8850 .8845 .8839 .8833 .8827 .8822 .8816 .8810 29 .8805 .8799 .8794 .8788 .8782 .8777 .8772 .8766 .8761 .8756 30 .8750 .8744 .8739 .8734 .8728 .8722 .8717 .8712 .8706 .8701 31 .8696 .8690 .8685 .8679 .8674 .8669 .8663 .8658 .8653 .8647 32 .8642 .8637 .8631 .8626 .8621 .8615 .8610 .8605 .8600 .8594 33 .8589 .8584 .8578 .8573 .8568 .8562 .8557 .8552 .8547 .8542 34 .8537 .8531 .8526 .8521 .8516 .8511 .8505 .8501 .8496 .8491 35 .8485 .8480 .8474 .8469 .8464 .8459 .8454 .8449 .8444 .8439 36 .8434 .8429 .8423 .8418 .8413 .8408 .8403 .8398 .8393 .8388 37 .8383 .8378 .8373 .8368 .8363 .8358 .8353 .8348 .8343 .8339 38 .8333 .832^t .8323 .8318 .8313 .8309 .8304 .8299 .8294 .8289 39 .8284 .8279 .8274 .8269 .8264 .8259 .8254 .8250 .8245 .8240 40 .8235 .8230 .8225 .8220 .8215 .8211 .8206 .8201 .8197 .8192 41 .8187 .8182 .8177 .8173 .8168 .8163 .8158 .8154 .8149 .8144 42 .8139 .8134 .8130 .8125 .8121 .8116 .8111 .8107 .8102 .8097 43 .8092 .8088 .8083 .8078 .8074 .8069 .8064 .8060 .8055 .8051 44 .8046 .8041 .8037 .8032 .8027 .8022 .8018 .8014 .8008 .8004 45 .8000 .7995 .7991 .7986 .7981 .7978 .7973 .7968 .7964 .7959 46 .7955 .7950 .7945 .7940 .7936 .7932 .7928 .7923 .7919 .7914 47 .7910 .7905 .7901 .7897 .7892 .7887 .7883 .7878 .7874 .7870 48 .7866 .7861 .7856 .7852 .7848 .7844 .7839 .7835 .7830 .7826 49 .7821 .7817 .7812 .7808 .7804 .7799 .7795 .7791 .7786 .7782 50 .7778 .7773 .7769 .7765 .7760 .7756 .7752 .7747 .7743 .7739 Appendix 871 TABLE 179 —Continued. Specific Gravity 60° F. Degrees TENTHS OF DEGREES Baume 1 2 3 4 5 6 7 8 9 51 .7735 .7730 .7726 .7722 .7718 .7714 .7709 .7705 .7701 .7696 52 .7692 .7688 .7684 .7680 .7675 .7671 .7667 .7663 .7658 .7654 53 .7650 .7646 .7642 .7637 .7633 .7629 .7625 .7621 .7617 .7613 54 .7609 .7605 .7601 .7597 .7593 .7588 .7584 .7580 .7576 .7572 55 .7568 .7563 .7559 .7555 .7551 .7547 .7543 .7539 .7535 .7531 56 .7527 .7523 .7519 .7515 .7511 .7507 .7503 .7499 .7495 .7492 57 .7487 .7483 .7479 .7475 .7471 .7467 .7463 .7459 .7455 .7451 58 .7447 .7443 .7439 .7435 .7431 .7427 .7423 .7419 .7415 .7411 59 .7407 .7403 .7399 .7396 .7392 .7388 .7384 .7380 .7376 .7372 60 .7368 .7364 .7361 .7357 .7353 .7349 .7345 .7341 .7338 .7334 61 .7330 .7326 .7322 .7318 .7314 .7311 .7307 .7303 .7299 .7295 62 .7291 .7288 .7284 .7280 .7276 .7273 .7269 .7265 .7261 .7258 63 .7254 .7250 .7246 .7243 .7239 .7235 .7231 .7228 .7224 .7220 64 .7216 .7213 .7209 .7205 .7202 .7198 .7194 .7190 .7186 .7182 65 .7179 .7176 .7172 .7169 .7165 .7161 .7158 .7154 .7150 .7147 66 .7143 .7139 .7136 .7132 .7128 .7125 .7121 .7117 .7114 .7110 67 .7106 .7103 .7099 .7095 .7092 .7088 .7084 .7081 .7077 .7074 68 .7071 .7067 .7064 .7060 .7057 .7053 .7049 .7045 .7042 .7039 69 .7035 .7032 .7028 .7025 .7021 .7017 .7014 .7010 .7007 .7003 70 .7000 .6996 .6993 .6989 .6986 .6982 .6979 .6975 .6972 .6969 71 .6965 .6962 .6958 .6955 .6951 .6948 .6944 .6941 .6937 .6934 72 .6931 .6927 .6924 .6920 .6917 .6913 .6910 .6906 .6903 .6900 73 .6896 .6893 .6889 .6886 .6882 .6879 .6876 .6872 .6869 .6866 74 .6863 .6859 .6856 .6853 .6850 .6846 .6843 .6839 .6836 .6833 75 .6829 .6826 .6823 .6819 .6816 .6813 .6809 .6806 .6803 .6799 76 .6796 .6792 .6789 .6786 .6782 .6779 .6776 .6772 .6769 .6766 77 .6763 .6760 .6757 .6753 .6750 .6746 .6743 .6740 .6737 .6734 78 .6731 .6727 .6724 .6721 .6717 .6714 .6711 .6708 .6705 .6702 79 .6698 .6695 .6692 .6689 .6686 .6683 .6679 .6676 .6673 .6670 80 .6667 .6663 .6660 .6657 .6654 .6651 .6648 .6645 .6641 .6638 81 .6635 .6632 .6629 .6626 .6623 .6619 .6616 .6613 .6610 .6607 82 .6604 .6601 .6598 .6595 .6591 .6588 .6585 .6582 .6579 .6576 83 .6573 .6570 .6567 .6563 .6560 .6557 .6554 .6551 .6548 .6545 84 ,6542 .6538 .653e .6533 .6530 6527 ,6524 .6521 .6518 .6515 85 .6515 .650£ .650C .6503 ,650C .6496 .6493 .6490 .6487 .8484 86 .8481 .6478 .647^ .6472 .046S .6466 ,6463 ,6460 ,6457 .6454 87 .6451 > .644f .644f ) .6443 .644C .6437 .643^ .6431 .6428 .6425 88 .6421 > .64U .641( ) .6413 .641C .6407 .640^ .6401 ,6398 .6396 89 639: 5 .639f ) .638/ ' .638-^ .6381 6378 .637.'5 .6372 .636e .6367 90 .636^ \ 636] 635J i 635^ 6351 .634^ 1 634( .6343 634r ,6338 872 Appendix TABLE 180. Specific Gravity at ^___: corresponding to degrees Baume for liquids 60° F. heavier than water. Sp, Gr. 60° F,: 145 145 — Deg. Baume SPECIFIC GRAVITY (0 Baume degreesr=145 — | Sp. G r. 60 60°=1 / ^\ I Sp. Gr. 60 ^F. 1 ^ 60°=F. J TENTHS OF DEGREES Degrees Baume 1 2 3 4 5 6 7 8 9 1.0000 1.0007 1.0014 1.0021 1.0028 1.0035 1.0042 1.0049 1.0055 1.0062 1 1.0069 1.0076 1.0083 1,0090 1.0097 1.0105 1.0112 1,0119 1.0126 1.0133 2 1.0140 1.0147 1.0154 1,0161 1,0168 1.0175 1.0183 1.0190 1.0197 1.0204 3 1.0211 1.0218 1.0226 1,0233 1.0240 1.0247 1.0255 1.0262 1.0269 1,0276 4 1.0284 1.0291 1.0298 1.0306 1.0313 1.0320 1,0328 1.0335 1.0342 1.0350 5 1.0357 1.0365 1.0372 1.0379 1.0387 1.0394 1.0402 1,0409 1.0417 1.0424 6 1.0432 1.0439 1.0447 1.0454 1.0462 1.0469 1.0477 1,0484 1.0492 1,0500 7 1.0507 1.0515 1 . 0522 1.0530 1 . 0538 1.0545 1.0553 1.0561 1.0569 1.0576 8 1.0584 1.0592 1.0599 1.0607 1.0615 1.0623 1.0630 1.0638 1.0646 1.0654 9 1.0662 1.0670 1.0677 1.0685 1.0693 1.0701 1.0709 1.0717 1.0725 1.0733 10 1.0741 1.0749 1.0757 1.0765 1.0773 1.0781 1.0789 1.0797 1.0805 1.0813 11 1.0821 1.0829 1.0837 1.0845 1.0853 1.0861 1.0870 1.0878 1.0886 1.0894 12 1.0902 1.0910 1.0919 1.0927 1.0935 1,0943 1.0952 1,0960 1,0968 1.0977 13 1.0985 1.0993 1 . 1002 1.1010 1.1018 1.1027 1 . 1035 1.1043 1 . 1052 1 . 1060 14 1 . 1069 1 . 1077 1 . 1086 1.1094 1.1103 1,1111 1.1120 1.1128 1.1137 1.1145 15 1.1154 1.1162 1.1171 1.1180 1.1188 1.1197 1.1206 1.1214 1 . 1223 1 . 1232 16 1 . 1240 1.1249 1 . 1258 1.1267 1.1275 1.1284 1 . 1293 1.1302 1.1310 1.1319 17 1 . 1328 1.1337 1 . 1346 1 . 1355 1.1364 1 . 1373 1.1381 1 . 1390 1 . 1399 1 . 1408 18 1.1417 1 . 1426 1.1435 1 . 1444 1 . 1453 1 . 1462 1 . 1472 1.1481 1 . 1490 1 . 1499 19 1 . 1508 1.1517 1 . 1526 1.1535 1 . 1545 1 . 1554 1.1563 1 . 1572 1.1581 1.1591 20 1.1600 1.1609 1.1619 1.1628 1 , 1637 1 . 1647 1.1656 1 . 1665 1 . 1675 1.1684 21 1.1694 1,1703 1.1712 1 . 1722 1,1731 1.1741 1 . 1750 1 . 1760 1 . 1769 1,1779 22 1.1789 1.1798 1 . 1808 1.1817 1.1827 1 , 1837 1 . 1846 1 . 1856 1.1866 1 . 1876 23 1 . 1885 1.1895 1.1905 1.1915 1 . 1924 1,1934 1 . 1944 1 , 1954 1 . 1964 1.1974 24 1 . 1983 1.1993 1 , 2003 1.2013 1 . 2023 1,2033 1 . 2043 1 , 2053 1.2063 1.2073 25 1.2083 1.2093 1.2104 1.2114 1,2124 1,2134 1.2144 1.2154 1.2164 1.2175 26 1.2185 1.2195 1.2205 1.2216 1.2226 1,2236 1 . 2247 1,2257 1,2267 1.2278 27 1 . 2288 1.2299 1.2309 1.2319 1.2330 1.2340 1.2351 1.2361 1.2372 1.2383 28 1.2393 1 . 2404 1.2414 1.2425 1.2436 1.2446 1.2457 1.2468 1.2478 1.2489 29 1 . 2500 1.2511 1,2522 1.2532 1.2543 1.2554 1,2565 1.2576 1.2587 1.2598 30 1.2609 1.2619 1.2630 1.2641 1.2652 1.2663 1 . 2674 1 . 2685 1.2697 1.270S 31 1.2719 1.2730 1.2741 1.2752 1,2763 1.2775 1.2786 1.2797 1.2808 1.2820 32 1.2831 1 . 2842 1.2854 1.2866 1.2877 1 . 2888 1 . 2900 1.2912 1.2923 1.2934 33 1.2946 1.2957 1.2968 1.2979 1.2991 1 . 3004 1.3016 1 . 3028 1.3040 1 . 3052 34 1 . 3003 1 . 3075 1 . 3087 1.3098 1.3110 1.3122 1.3134 1.3146 1.3158 1.3170 35 1.3182 1.3194 1.3206 1.3218 1 . 3230 1.3242 1.3254 1.3266 1.3278 1 . 3290 36 1.3302 1.3314 1.3326 1.3339 1.3352 1.3364 1.3376 1.3389 1.3401 1.3414 Appendix 873 TABLE 180— Continued. SPECIFIC GRAVITY 60° F. TENTHS OF DEGREES Degrees Baume 1 2 3 4 5 6 7 8 9 37 1.3426 1 . 3438 1.3451 1 . 3464 1.3476 1.3488 1 . 3500 1,3512 1.3525 1 . 3528 38 1.3551 1 . 3564 1.3577 1.3589 1.3602 1.3615 1.3627 1.3640 1.3653 1.3666 39 1.3679 1.3692 1 . 3705 1.3718 1.3731 1 . 3744 1.3757 1.3770 1.3783 1.3796 40 1 . 3809 1 . 3822 1.3836 1.3849 1 . 3862 1.3875 1.3888 1 . 3902 1.3915 1 . 3928 41 1.3942 1.3955 1.3969 1.3982 1 . 3996 1 . 4009 1.4023 1.4036 1.4050 1.4064 42 1.4078 1.4091 1.4105 1.4118 1.4132 1.4146 1.4160 1.4174 1.4188 1.4202 43 1.4216 1.4230 1.4244 1.4258 1.4272 1.4286 1.4300 1.4314 1.4328 1.4342 44 1.4356 1.4370 1.4385 1.4399 1.4413 1.4428 1.4442 1.4456 1.4471 1.4485 45 1 . 4500 1.4514 1.4529 1.4543 1.4558 1.4573 1.4588 1.4602 1.4617 1.4632 46 1.4646 1.4661 1.4676 1.4691 1.4706 1.4721 1.4736 1.4751 1.4766 1.4781 47 1.4796 1.4811 1.4826 1.4841 1.4856 1.4871 1.4887 1.4902 1.4917 1.4933 48 1.4948 1 . 4963 1.4979 1.4994 1.5010 1.5026 1.5041 1.5057 1.5073 1.5088 49 1.5104 1.5120 1.5136 1.5142 1.5167 1.5182 1.5199 1.5215 1.5231 1.5247 50 1 . 5263 1 . 5279 1.5295 1.5311 1.5327 1.5343 1 . 5360 1.5376 1.5392 1.5409 51 1.5425 1 . 5442 1 . 5458 1.5474 1.5491 1 . 5508 1.5525 1.5541 1 . 5558 1.5574 52 1.5591 1.5608 1.5625 1.5642 1.5659 1.5676 1.5693 1.5710 1 . 5727 1.5744 53 1.5761 1.5778 1.5795 1.5812 1.5829 1.5847 1.5864 1.5882 1.5899 1.5916 54 1.5934 1.5951 1.5969 1.5986 1.6004 1.6022 1.6040 1.6037 1.6076 1.6093 55 1.6111 1.6129 1.6147 1.6165 1.6183 1.6201 1.6219 1.6237 1.6255 1.6274 56 1.6202 1.6310 1.6328 1.6347 1.6365 1.6384 1.6402 1.6421 1.6439 1.6458 57 1.6477 1.6496 1.6515 1.6534 1.6552 1.6571 1.6590 1.6609 1.6628 1.6647 5S 1 . 6666 1.6686 1.6705 1.6724 1.6743 1 . 6763 1.6782 1.6802 1.6821 1 . 6840 59 1 . 6860 1.6879 1.6899 1.6919 1.6939 1.6959 1.6979 1.6999 1.7019 1 . 7039 ■ 60 1.7059 1.7079 1.7099 1.7119 1.7139 1.7159 1.7180 1 . 7200 1.7221 1.7241 61 1.7262 1.7282 1.7303 1 . 7324 1.7344 1.7365 1 . 7386 1.7407 1.7428 1.7449 62 1.7470 1.7491 1.7512 1.7533 1 . 7554 1.7576 1.7597 1.7619 1.7630 1.7661 63 1.7683 1 . 7704 1.7726 1.7748 1.7769 1.7791 1.7813 1 . 7835 1 . 7857 1.7879 64 1.7901 1.7923 1.7945 1.7967 1 . 7990 1.8012 1.8034 1 . 8057 1.8080 1.8102 65 1.8125 1.8148 1.8170 1.8193 1.8216 1.8239 1 . 8262 1.8285 1.8308 1.8331 66 1 . 8354 1.8377 1.8401 1.8424 1.8447 1.8471 1.8494 1.8518 1 . 8542 1.8566 67 1 . 8590 1.8614 1 . 8638 1.8662 1.8686 1.8710 1.8734 1.8758 1.8782 1.8806 68 1.8831 1.8855 1 . 8880 1.8905 1.8929 1 . 8954 1.8979 1.9904 1.9029 1.9054 69 1.9079 1.9104 1.9129 1.9154 1.9180 1.9205 1.9231 1.9256 1.9281 1.9307 70 1.9333 1 . 9359 1.9385 1.9411 1.9437 1.9463 1.9489 1.9515 1.9542 1.9568 874 Appendix TABLE 181. Properties of Saturated Steam/ Pressure Heat Heat of Total in Tempera- in vaporiza- Heat in Density or Volume Total pounds ture in liquid tion, or heat weight of 1 pressure per sq. in. degrees from latent unit.s of cubic ft. pound in above above Fahren- 32° in heat in from in pounds cubic vacuum vacuum heit units heat units water at 32° feet 1 101.99 70,0 1043.0 1113.1 0.00299 334 . 5 1 2 126.27 94.4 1026.1 1120,5 0.00576 173.6 2 3 141 ,.62 109.8 1015.3 1125.1 0.00844 118.5 3 4 153.09 121.4 1007.2 1128.6 0.01107 90.31 4 5 162.34 130.7 1000.8 1131.5 0,01366 73.21 5 6 170.14 138.6 995.2 1133.8 0,01622 61.67 6 7 176.90 145.4 990,5 1135.9 0.01874 53.37 7 8 182.92 151.5 986.2 1137.7 0.02125 47.06 '8 9 188.33 156.9 982.5 1139.4 0,02374 42.12 9 10 193.25 161.9 979.0 1140.9 0.02621 38.15 10 14.7 2 12". 00 180.9 965.7 1146.6 0.03794 26.36 14.7 15 213.03 181.8 965.1 1146.9 0.03826 26.14 15 20 227,95 196.9 954.6 1151.5 0.05023 19.91 20 25 240.04 209.1 946.0 1155.1 0.06199 16.13 25 30 250.27 219.4 938.9 1158.3 0.07360 13.59 30 35 259.19 228.4 932.6 1161.0 , 08508 11.75 35 40 267.13 236.4 927.0 1163.4 0.09644 10.37 40 45 274.29 243.6 922.0 1165,6 0.1077 9.287 45 50 280.85 250.2 917.4 1167,6 0.1188 8.414 50 55 286.89 256.3 913.4 1169.4 0.1299 7.696 55 60 292.51 261.9 909.3 1171.2 0.1409 7.097 60 65 297.77 267.2 905.5 1172.7 0.1519 6.583 65 70 302.71 272.2 902.1 1174.3 0.1628 6.143 70 75 307.38 276.9 898.8 1175.7 0.1736 5.762 75 80 311.80 281.4 895.6 1177.0 0.1843 5.426 SO 85 316.02 285.8 892.5 1178.3 0.1951 5.126 85 90 320.04 290.0 889.6 1179.6 0.2058 4.859 90 95 323.89 294.0 886.7 1180.7 0.2165 4.619 9.5 100 327.58 297.9 884.0 1181.9 0.2271 4.403 100 105 331.13 301.6 881.3 1182,9 0.2378 4.205 105 110 334.56 305.2 878.8 1184,0 0.2484 4.026 110 115 337.86 308.7 876.3 1185,0 0.2589 3.862 115 120 341.05 312.0 874.0 1186.0 0.2695 3.711 120 125 344.13 315.2 871.7 1186.9 . 2800 3.571 125 130 347.12 318.4 869.4 1187.8 0.2904 3.444 130 140 352.85 324.4 865.1 1189.5 0.3113 3.212 140 150 358.26 330.0 861.2 1191.2 0.3321 3,011 150 160 363.40 335.4 857.4 1192.8 . 3530 2 , 833 160 170 368.29 340.5 853.8 1194.3 0.3737 2,676 170 180 372.97 345.4 850.3 1195,7 . 3945 2.535 180 190 377.44 350.1 847.0 1197.1 0.4153 2.408 190 200 , 381.73 354.6 843,8 1198.4 0.4359 2.294 200 225 391.79 365.1 836.3 1201.4 0.4876 2.051 225 250 400.99 374.7 829.5 1204.2 0.5393 1.854 250 275 409.50 383.6 823.2 1206.8 0.5913 1.691 275 300 417.42 391.9 817.4 1209,3 0.644 1.553 300 325 424.82 399.6 811.9 1211.5 0,096 1.437 325 350 431.90 406.9 806.8 1213.7 0,748 1.337 350 375 438.40 414.2 801.5 1215.7 0.800 1.250 375 400 445.15 421.4 796.3 1217.7 0.853 1.172 400 500 466.57 444.3 779.9 1224.2 1.065 .939 500 ApPIvNDIX 875 TABLE 181- -Continued. Temper- ature in degrees Fahren- heit Total pressure above vacuum Heat in liquid from 32° in units Heat of vaporiza- tion, or latent heat in neat units Total heat in heat units from water at 32° Density or weight of cubic ft. in pounds Volume Tempern- of one ture in pound in degrees cubic Fahren- feet heit 32 0.089 0. 1091.7 1091.7 0.0003 3387. 32 60 0.254 28.12 1072.1 1100.2 . 0008 1244. 60 90 0.692 58.04 1051.4 1109.4 0.0021 474 . 6 90 120 1.683 88.10 1034.4 1118.5 . 0049 204.4 120 140 2.877 108.2 1016.4 1124.6 0.0081 123.2 140 150 3.706 118.3 1009.4 1127.7 0.0103 97.03 150 IGO 4.729 128.4 1002.3 1130.7 0.0130 77.14 160 170 5.98 138.5 995.3 1133.8 0.0162 61.85 170 180 7.50 148.5 988.3 1136.8 0.0200 50.01 180 190 9.33 158.6 981.3 1139.9 0.0245 40.73 190 200 11.52 168.7 974.2 1142.9 0.0299 33.40 200 210 14.12 178. S 967.2 1146.0 0.0363 27.57 210 220 17.19 188.9 960 . 1 1149.0 0.0435 22.98 220 225 18.91 193.9 956.7 1150.6 0.0476 20.99 225 230 20.78 198.9 953.2 1152.1 0.0521 19.20 230 235 22.80 204.0 949.6 1153.6 0.0569 17.59 235 240 24.98 209.0 946.1 1155.1 0.0619 16.14 240 245 27.33 214.1 942.6 1156.7 0.0674 14.83 245 250 29.86 219.1 939 . 1 1158.2 0.0733 13.65 250 255 32.57 224.1 935 . 6 1159.7 0.0795 12.57 255 260 35.48 229.2 932.0 1161.2 0.0862 11.60 260 265 38.60 234.2 928.6 1162.8 0.0933 10.72 265 270 41.94 239.3 925.0 1164.3 0.1008 9.918 270 275 45.51 244.3 921.5 1165.8 . 1088 9.187 275 280 49.33 249.3 918.0 1167.3 0.1173 8.521 280 285 53.39 254.4 914.5 1168.9 0.1264 7.913 285 290 57.72 259.4 911.0 1170.4 0.1359 7.356 290 295 62.33 264.4 907.4 1171.9 0.1461 6.847 295 300 67.22 269.5 903.9 1173.4 0.1567 6.380 300 305 72.42 274 . 5 900.5 1175.0 0.1680 5.952 305 310 77.83 279.6 896.9 1176.5 0.1799 5.558 310 315 83.77 284.8 893.2 1178.0 0.1925 5.195 315 320 89.95 290.0 889.5 1179.5 . 2058 4.861 320 325 96.48 295.2 885.9 1181.1 0.2197 4.552 325 330 103.38 300.5 882.1 1128.6 0.2343 4.267 330 335 110.66 305.7 878.4 1184.1 0.2498 4.004 335 340 118.34 310.9 874 . 7 1185.6 . 2660 3.760 340 345 126.43 316.1 871.1 1187.2 . 2830 3.534 345 350 134.95 321.4 867.3 1188.7 0.3008 3.324 350 355 142.91 326 . 6 863.6 1190.2 0.3195 3.130 355 360 153.33 331.8 859.9 1191.7 0.3391 2.949 360 365 163.22 337.1 856.2 1193.3 0.3597 2.780 365 370 173.60 3,42.3 852.5 1194.8 0.3812 2.623 370 375 184.49 347.5 848.8 1196.3 0.4038 2.476 375 380 195.91 352.8 845.0 1197.8 0.4276 2.338 380 385 207.87 358.0 841.4 1199.4 0.4521 2.212 385 390 220.39 363.2 837.7 1200.9 0.4780 2.092 390 395 233.50 368.4 834.0 1202.4 0.5051 1.980 395 400 247.21 373.7 830.2 1203.9 0.5336 1.874 400 405 261.55 378.9 826.6 1205.5 0.5633 1.775 405 410 276.54 384.1 822.9 1207.0 0.5945 1.682 410 415 292.21 389.4 819.1 1208.5 0.6270 1.595 415 420 308.57 394.6 815.4 1210.0 0.6610 1.512 420 425 325.65 399.8 811.8 1211.6 0.6970 1.434 425 876 Appendix TABLE 182. Tables for conveiting U. S. Weights and Measures Customary to Metiic.= ;.INEAR. CAPACITY. Inches Feet to Yards to Miles to Fluid drams to Fluid ounces Liquid Gallons to millimeters. meters. meters. kilometers. I or cubic centimeters. milliliters. liters. I 25.4001 0.304801 0.914402 1.60935 3-70 29-57 094633 3-78533 2 508001 0.609601 1.828804 3.21869 2 7-39 ^2- '5 I.S9267 7.57066 ^ 76.2002 0.914402 2.743205 4.82804 3 11.09 88.72 2.83900 11.35600 4 101.6002 1. 219202 3-657607 6.43739 4 14-79 118.29 378533 i5-'4'33 5 127.0003 1.524003 4.572009 8.04674 5 18.48 147.87 473167 18.92666 6 152.4003 1.828804 5.48641 1 9.65608 6 22,18 177-44 5.67800 22.71199 7 177.8004 2.133604 6.400813 11.26543 7 25.88 207.01 6.62433 26.49733 8 203.2004 2.438405 7-315215 12.87478 8 29-57 '}^A 7.57066 30.28266 9 228.6005 2.743205 8.229616 14.48412 9 3327 266.16 8.51700 34.06799 SQUA RE. WEIGHT. Square inches to square cen- timeters. Square feet to square decimeters. Square yards to square meters. Acres to hectares. Crams to milligrams. Avoirdu- pois ounces to grams. Avoirdu- pois pounds to kilo- grams. Troy ounces lo grams. 6.452 9.290 0.836 0.4047 I 64.7989 28.3495 0.45359 31.IO34S 2 12.903 18.581 ,.672 0.8094 2 129.5978 56.6991 0.90718 62.20696 1 '9-355 27.871 2.508 I.2141 ,"? 194.3968 85.0486 1.36078 93-3'044 4 25.807 ' 37-161 3-345 I.6187 4 259- '957 1 13-3981 1. 81 437 124.41392 S 32.258 46.452 4.181 2.0234 5 323-9946 141.7476 2.26796 155-51740 6 38.710 55-742 5.017 2.4281 6 388.7935 170.0972 27215s 186.62088 7 45.161 65.032 S-853 2.8328 7 453-5924 198.4467 3-17515 217.72437 248.82785 8 5'-6i3 74-323 6.6S9 >2375 8 5'839'3 226.7962 3.62874 9 58.065 83-613 7-525 3.6422 9 583- '903 25S-'457 4.08233 279-93133 CUBIC. I Gunter's chain = I sq. statute mile = 20.1168 259.000 meters, lectares. Cubic inches to cubic cen- timeters. Cubic feet to cubic meters. Cubic yards to cubic meters. Bushels to hectoliters. I fathom = I nautical mile ^ 1.829 '853-25 meters, meters. I "6.387 O.02S32 0.765 035239 2 32774 0.05663 1.529 0.70479 I foot = 0.304801 meter. 3 4 5 49.161 65.549 81.936 0.08495 0.11327 0.14159 2.294 3.058 3823 1.05718 1.40957 1.76196 I avoir, pound = 15432-35639 grains = 453.592427 1. 000 k 7 grams, ilogram. 6 98-323 0.16990 4-587 2.1 1436 7 1 14.710 0.19822 5-352 2.46675 8 131.097 0.22654 6.1 16 2.81914 9 147.484 0.25485 6.881 3-'7iS4 Appendix 877 TABLE 183. Tables for converting U. S. weights and measures. Metric to customary.' LINEAR. CAPACITY. Meters to inches. Meters to feet. Meters to yards. Kilometers to miles. Millili- ters or cubic cen- timeters to fluid drams. Centi- liters to fluid ounces. Liters to quarts. Deca- liters to gallons. Hecto- liters to bushels. I 3 4 5 39-3700 78.7400 1 18. 1 100 157.4800 196.8500 3.28083 6.56167 9.84250 '3- '2333 16.40417 1.09361 1 2.187222 3280833 4-374444 5.468056 0.62137 1.24274 1. 864 11 2.48548 3.10685 r 3 4 5 0.27 0.54 0.81 i.oS 1-35 C C 1 1 1 -338 .676 .014 -353 .691 1.0567 2.II34 3.1701 4.2268 5-2836 2.6418 5-2836 7-9253 10.5671 13.2089 5-6756 8.513s 11-3513 14.1891 6 7 8 9 236.2200 275.5900 314.9600 354.3300 19.68500 22.96583 ■ 26.24667 29.52750 6.561667 7.65^278 8.748889 9.842500 3.72822 4-34959 4.97096 5-59233 6 7 8 9 1.62 1.89 2.16 2.43 2.029 2.367 2.705 3-043 6-3403 7-3970 8.4537 9.5104 15-8507 18.4924 21.1342 23.7760 17.0269 19.8647 22.7026 25.5404 SQUAl ^E. WEIGHT. I 2 3 4 5 Square centimeters to square inches. Square meters to square feel. Square meters to square yards. Hectares to acres. I 3 4 5 Milli- grams to grains. Kilo- grams to grains. Hecto- grams to ounces avoirdupois. Kilo- grams to pounds avoirdupois. 0.1550 0.3100 0.4650 0.6200 0.7750 10.764 21.528 32.292 43-055 53-819 1.196 2.392 3.588 4.784 5.980 2.471 4-942 7-413 9.884 12355 0.01543 0.03086 0.04630 0.06173 0.07716 15432.36 30864.7 1 46297.07 61729.43 77161.78 35274 7.0548 10.5822 14.1096 17.6370 2.20462 4-40924 6.61387 8.81849 1 1. 0231 1 6 7 8 9 0.9300 1.0850 1.2400 1-3950 64-583 75-347 86.1 II 96.875 7.176 8.372 9.568 10.764 14.826 17.297 19.768 22.239 6 7 8 9 0.09259 0.10803 0.12346 0.13889 92594.14 108026.49 123458.85 138891.21 21.1644 24.6918 28. 2192 31.7466 13-22773 15-43236 T 7.63698 19.84160 CUBIC. WEIGHT. I 3 4 5 Cubic centimeters to cubic inches. Cubic decimeters to cubic inches. Cubic meters to cubic feet. Cubic meters to cubic yards. Quintals to pounds av. Milliers or tonnes to pounds av. Kilograms to ounces Troy. 0.0610 0.1220 O.183I 0.2441 0.3051 61.023 122.047 183.070 244-094 305-117 35-314 70.269 105.943 141.258 176.572 1.308 2.616 3-924 5-232 6.540 I 2 3 4 5 220.46 440.92 661.39 881.85 1102.31 2204.6 4409.2 6613.9 8818.5 1 1023.1 32.1507 64.3015 96.4522 1 28.6030 160.7537 6 7 8 9 0.3661 0.4272 0.4882 0.5492 366.140 427.164 488.187 549-210 211.887 247.2bl 282.516 317-830 7.848 9.156 10.464 II.77I 6 7 8 9 1322.77 1543-24 1763.70 1984.16 13227.7 15432-4 17637.0 19841.6 192,9045 225.0552 257.2059 289.3567 878 Appendix TABLE 184. Equivalent of Metric and British Imperial Weights and Measures. Metric to Imperial.^ LINEAR MEASURE. I millimeter (mm.) (.001 m.) I centimeter (.oi m.^ 1 decimeter (.1 m) I METER (m.) I dekameter (10 m.) I hectometer (100 m.) I kilometer (1,000 m.) I myriameter ( 10,000 m.) I micron . . = 0-03937 in- = 0.39370 " = 3-93701 " (39-370113 " = ] 3.280843 ft. ( 1.09361425 yds- = 10.93614 = 109.361425 = 0.62137 mile. ^ 6.21372 miles. = o.ooi mm. SQUARE MEASURE. I sq. centimeter . . I sq. decimeter (100 sq. centm.) I sq. meter or centi- are (100 sq. dcm.) I ARE (100 sq. m.) I hectare (100 ares or 10,000 sq. m.) = 0.1550 sq. ni. = 15-500 sq. in. ^ \ 10.7639 sq. ft. ( 1.1960 sq. yds. = 119.60 sq. yds. = 2.47 II acres. CUBIC MEASURE. I cub. centimeter (c.c.) (1,000 cubic millimeters) I cub. decimeter (c.d.) (1,000 cubic centimeters) I CUB. METER ) or stere > . . = (1,000 c.d.) ) = 0.0610 cub. in. = 61.024 •' " [ 35-3148 cub. ft. I 1-307954 cub. yds. MEASURE OF CAP.-\CITy. I milliliter (ml.) (.001 liter) I centiliter (.01 liter) I deciliter (.1 liter) . I LITER ( 1,000 cub. centimeters or I cub. decimeter) I dekaliter (loliters) I hectoliter (100 " ) I kiloliter (1,000 " ) = 0.0610 cub. iq. __ I 0.61024 " " I 0.070 gill. = 0.176 pint. = 1.759S0 pints. = 2.200 gallons. = 2.75 bushels. = 3-437 quarters. APOTHECARIES' MEASURE. I cubic centi- ) meter (i > gram w't) ) I cub. millimeter : 0.03520 fluid ounce. 0.28157 fiuid drachm. 1 5-43236 gyai'is weight. 0.01693 minim. AVOIRDUPOIS WEIGHT. I milligram (mgr.) . . I centigram (.01 gram.) I decigram (.1 " ) I GRAM I dekagram (10 gram.) I hectogram (too " ) 0.01543 gram. 0.15432 " i'54324 grains. 15-43236 , " 5.64383 drams, 3.52739 oz. ( 2.2046223 lb I KILOGRAM (1,000" ) = -j 15432.3564 ( grains. =22.04622 lbs. = 1. 9684 1 cwt. I myriagram (10 kilog.) I quintal (100 " ) I millier or tonne [ (1,000 kilog.) ) ■ ■ = 0.9842 ton. TROY WEIGHT. 0.03215 oz. Troy. 0.64301 pennyweight. 1 5.43236 grains. APOTHECARIES' WEIGHT. 0.25721 drachm. 0.77162 scruple. 15.43236 grains. Appendix 879 TABLE 185. Equivalents of Metric and British Imperial weights and Measures. Metric to imperial." LINEAR MEASURE. MEASURE OF CAPACITY Millimeters tc inches Meters 10 feet. Meters to yards. Kilo- meters to luiles. ' 1 Lita-s to pints Dekaliters to gallons Hectoliters to busuels. Kiloliters to quarters. I 3 4 5 6 7 8 9 0.0393701 1 0.07874023 O.I 181 1034 0.15748045 0.19685056 0.23622968 0.27559079 3 1 496090 o-3S433'02 3.28084 6.56169 9-84253 13-12337 16.40421 1 9. 68 506 22.96590 26.24674 29.52758 1.09361 2.18723 3.28084 437446 5.46S07 6.56169 7.65530 8.74891 9-84253 0.62137 ; 1.24274; 1. 8641 2 ! 2.48549 ; 3.106S6 372823 4.34960 4.97097 559235 3 4 5 6 7 8 9 1.75980 3.51961 5-27941 7.03921 S.79902 10.55882 12.31862- 14.07S42 15-83S23 2.19975 4-3995' 6.59926 8.79902 10.99877 13.. 9852 15.39828 17.59803 19.79778 2.74969 5-4993'^ 10.99877 13.74846 16.49815 19.24785 21-99754 24-74723 3-43712 6.87423 10.3' 135 13.74846 17.. 8558 20.62269 24.05981 27-49692 30-93404 SQl JARE MEASURE. WEIGHT (Avoirdupois). Square centimeters to square •.iiches. Square meters to square feet. Square meters to square yards. Hectares to acres. I 3 4 5 6 7 8 9 Milli- grams to grains. Kilograms to grains. Kilo- grams to pounds. Quintals to hundred- weights. . I 3 4 5 6 7 8 9 0.15500 0.31000 0.46500 0.62000 0.77500 0.93000 I.0S500 1.24000 1.39501 10.76393 21.52786 32.29179 43-05572 53.81965 64.58357 7534750 86 1 1143 96.87536 I -19599 2.39198 3-58798 478397 5.97996 7-17595 8.37194 9.56794 10.76393 2.4711 49421 7-4132 9.8842 12.3553 14.8263 17.2974 19.7685 22.2395 0.01543 0.03086 0.04630 0.06173 0.07716 0.09259 0.10803 0.12346 0.13889 ■5432-356 30864.713 46297.069 61729.426 77161.782 92594.138 I0S026.495 123458.S5I 138891.208 2.2046? 4.40924 66.387 8.81849 11. 02311 13-22773 15-43236 17.63698 1 9.84 1 60 1.9684. 3.93683 5.90524 787365 9.84206 11.8.048 13.77889 •5-74730 17.71572 CUBIC MEASURE. Apothe- caries' Measure. Avoirdupois Troy Weight. Apo-thr- CARIKS' Wkight. Cubic decimeters to cubic inches. Cubic meters to cubic feet. Cubic meters to cubic yards. Cub. cen- timeters to fluid drachms. Milliers or 'tonnes to tons. Grams to minces Troy. Grams to penny, weights. Grams to scruples. I 2 3 4 5 6 7 8 9 61.02390 122.04781 183.07171 244.09561 305- "952 366.14342 427.16732 488.19123 549-2'5>3 35-3'476 70.62952 105.94428 141.25904 176.57379 211.8S855 247.20331 282.51807 317-83283 •-30795 2.61591 392386 5.23182 6-53977 7-84772 9.15568 10.46363 "77159 0.28157 0.56314 0.84471 ..12627 1.40784 1 .6894 1 1.97098 2-25255 2.53412 I 3 4 5 6 7 8 9 0.98421 1 .9684 1 2.95262 3-93683 -4.92103 590524 6.88944 7-S7365 8.85786 0.03215 0.06430 0.09645 0. 1 2860 0.1607s 0.19290 0.22506 0.25721 0.28936 0.64301 1.28603 ..92904- 2.57206 3-21507 3.85809 4.501.0 5.14412 S-787'3 0.77162 •-54324 2.31485 3.08647 3.85809 4.6297. 5.40.32 6.17294 6.94456 880 Appendix TABLE 186. Equivalent of British Imperial and Metric weights and measures. Imperial to metric.^" LINEAR MEASURE. {25.400 milli- meters. 0.30480 meter. 0-914399 " 5.0292 meters. I inch .... I foot (t2 in.) . I YARD (3 ft.) . I pole (5i yd.) . I chain (22 yd. or 100 links) S I furlong (220 yd.) = 201.168 " ; , ^ J V J 1-6093 kilo- 1 mile (1,760 yd.) . = I meters. SQUARE MEASURE. I square mch . . = j I sq. ft. (144 sq. in.) = \ I SQ. YARD (9 sq. ft.) = ^ I perch (30^ sq. yd.) = | I rood {40 perches) = I ACRE (4840 sq. yd.) = I sq. mile (640 acres) = J 259.00 hectares. 6.4516 sq. cen- timeters. 9.2903 sq. deci- meters. 0.836126 sq. meters. 25.293 sq. me- ters. lO-i 17 ares. 0.40468 hectare. CUBIC MEASURE. I cub. inch= 16.387 cub. centimeters. I cub. foot' (1728 ) _ (0028317 cub^me cub. in.) I ci;b. yard (27 cub. ft.) ter, or 28.317 ( cub. decimeters. 0.76455 cub. meter. APOTHECARIES' MEASURE. I gallon (8 pints or J 160 fluid ounces) ) I fluid ounce, f 3 ( S (8 drachms) \ ~ ( I fluid drachm, f 5 1 i (60 minims) ) "^ ( I minim, n\ (0.91 146 ( f grain weight) \ \ 4-5459631 liters. !8.4i2^ cubic centimeters. 3.5515 cubic centimeters. 0.05919 cubic centim.eters. Note. — The Apotliecaries' gallon is of the same capacity as the Imperial gallon. MEASURE OF CAPACITY. I gill = 1.42 deciliters. 1 pint (4 gills) . . , = 0.568 liter. I quart (2 pints) . . = 1.136 liters. I GALLON (4 quarts) = 4.5459631 " I peck ( 2 galls.) . . = 9.092 " I bushel (8 galls.) . = 3.637 dekaliters. I quarter (8 bushels) = 2.909 hectoliters. AVOIRDUPOIS WEIGHT, ^ ( 64.8 m i 1 1 i - } grams. = 1.772 grams. --= 28.350 '■ = 0.45359241 kilogr. = 6.350 = 12.70 " _ \ 50-So " I 0.50S0 quintal. ( 1. 0160 tonnes S or I016 kilo- f "rams. 1 cirain .... ! oiificc (16 dr.) . I POUNii ( 16 oz. or 7.000 grains) I stiiiie (14 lb.) . I quarter (28 lb.) I hundredweight ) (112 lb.) ( I ton (20 cwt.) TROY WEIGHT. I Troy OUNXF. (480 ) _ 31.1035 grams. ,i,ranis avoir.) J "^ -^^ * 1 pennyweight (24 / _^_ „ grains) j '^■'^ Note. — The Troy gr.iin is of the same weight as the Avoirdupois grain. APOTHECARIES' WEIGHT. I ounce (8 drachms) ^31.1035 grams. I drachm,3i (3 scru- J __ -cog « pies) j 3- I scruple, 9i (20 I - u grains) I = ^-296 Note. — The Apothecaries' ounce is of the same weight as the Troy ounce. The Apothecaries' grain is also of the same weight as the Avoirdupois grain. Appendix 881 TABLE 186— Continued. Equivalent of British Imperial and metric weights and measures. Metric." Imperial to LINE.-VR MEASURE. MEASURE OF CAPACITY. Inches to centimeters. Feet to meters. Yards to meters. Miles to kilo- meters. i Quarts to liters. Gallons to liters. Bushels to dekaliters. Quarters 10 hectoliters. I 2 3 4 5 6 7 8 9 2-539998 5.079996 7.619993 10. 1 59991 12.699989 15.239987 17-779984 20.319982 22.8599S0 0.30480 0.60960 0.91440 1.21920 1.52400 1.82880 2.13360 2.43840 2.74320 091440 1.82880 2.74320 3.65760 4.57200 5.48640 6.40080 7-3'5i9 8.22959 1.60934 3.21869 4.82803 6.43737 8.04671 9.65606 11.26540 12.87474 I4.4840S I 2 3 \t 6 7 8 9 1. 1 3649 2.27298 3-40947 4-54596 5-68245 6.81894 7-95544 9.09193 10.22842 4-54596 9-09' 93 13-63789 18.18385 22.729S2 27-27578 31.82174 36.36770 40.91367 363677 7-27354 10.91031 14.54708 18.18385 21 82062 25-45739 29.09416 3273093 2.90942 5.81883 8-72825 11.63767 14.54708 17.45650 20.36591 23-27533 26.18475 SQUARE MEASURE. WEIGHT (Avoirdupois). Square inches to square centimeters. Square feet to square decimeters. Square yarrli 10 square meters. Acres to hectares. Grains to milli- grams. Ounces to grams. Pounds to kilo- grams. Hundred- weights to quintals. I 3 4 5 6 7 8 9 6.45159 12.90318 '9-35477 25.80636 32-25794 38-70953 45.r6ii2 51.61271 58.06430 9.29029 18.58058 27.87086 37-'6ii5 46.45144 55-74'73 65.03201 74-32230 83.61259 0.83613 1.67225 2. 508 38 3-3445° 4.18063 5.01676 5.852S8 6.68901 7-525'3 0.40468 0.80937 I.21405 1. 61874 2.02342 2.42811 2.83279 3-23748 3.64216 I 2 3 4 5 6 7 8 9 64.79892 129.59784 '94-39675 259- '9567 323-99459 38S.7935' 453-59243 5'8.39'35 583.19026 28.34953 56.69905 85.04858 H3.39811 i4'-74763 170.09716 198.44669 226.79621 255-'4574 0.45359 0.90718 1.36078 I.81437 2.26796 2.72155 3-'75'5 3.62874 4.0S233 0.50802 1.01605 1.52407 2.03209 2.54012 3.04814 3-55616 4.06419 4.57221 CUBIC MEASURE. Apothe- caries' Measure. Avoirdupois (con/.). Troy Weight Apothe- caries' Weight Cubic inches to cubic centimeters. Cubic feet to cubic meters. Cubic yards to cubic meters. Fluid • drachms to cubic centi- meters. Tons to miUiers or tonnes. Ounces to grains. Penny- weights to grams. Scruples to grams. I 2 3 4 5 6 7 8 9 16.38702 32-77404 49.16106 65.54808 81.935II 98.32213 114.70915 131.09617 147.48319 0.02832 0.05663 0.08495 O.I 1327 O.I4I58 0.16990 0.19822 0.22653 0.25485 0.76455 1.52911 2.29366 3.05821 3.82276 4.58732 6.1 1642 6.88098 .3- 55 '53 7.10307 10.65460 14.20613 17-75767 21.30920 24.86074 28.41227 31.96380 I 2 3- 4 5 I I.O1605 2.03209 3.04814 4.06419 5.08024 6.09628 7-"233 .8.12838 9.14442 31.10348 62.20696 93-3'044 124.41392 i55-5'740 186.62088 217-72437 248.82785 279-93.' 33 i-555'7 4.66552 6.22070 7-77587 9-33104 10.88622 12.44139 13-99657 1.29598 2.59196 3.88794 5.18391 6.47989 7-77587 9.07185 10.36783 11.66381 882 Appendix TABLE 187. Miscellaneous equivalents of Metric weights and measures.' LINEAR MEASURES. I mil (.001 in.) = 25.4001 fi I in. = .000015783 mile I hand (4 in.) = 10.16002 cm I link (.66 ft.) = 20.11684 cm I span (9 in.) = 22.86005 cm I fathom (6 ft.) = 1.828804 m I rod (25 links) = 5.029210 m I chain (4 rods) = 20.11684 m I light year (9.5 X 10" km) = 5.9 x lo^^ miles I par sec (31 X 10'^ km) = 19 X 10" miles sV in. = -397 mm jV in. = .794 mm A in. = 1.588 mm J in. = 3.175 mm I in. = 6.350 mm 5 in. = 12.700 mm I Angstrom unit = .0000000001 m I micron (fj.) = .000001 m = .00003937 in. I millimicron (m/x) = .000000001 m I m = 4.970960 links = 1.0936 11 yds. = .198838 rod = .0497096 chain SQUARE MEASURES. I sq. link (62.7264 sq. in.) = 404.6873 cm' I sq. rod (625 sq. links) = 25.29295 m' I sq. chain (16 sq. rods) = 404.6873 m^ I acre (10 sq. chains) = 4046.873 m^ I sq. mile (640 acres) = 2.589998 km^ I km* = .3861006 sq. mile I m* = 24.7104 sq. links = 10.76387 sq = -039537 chain ft- sq. rod. = .00247104 sq. CUBIC MEASURES. I board foot (144 cu. in) = 2359.8 cm' I cord (128 cu. ft.) = 3.625 m* CAPACITY MEASURES. I minim (TTl) = .0616102 ml I fl. dram (6oTri) = 3.69661 ml I fl. oz. (8 fl. dr.) = 1.80469 cu. in. = 29.5729 ml I gill (4 fl. oz.) = 7.21875 cu. in. = 118.292 ml I liq. pt. (28.875 cu. in.) = .473167 1 I liq. qt. (57.75 cu. in.) = .946333 1 I gallon (4 qt., 231 cu. in.) = 3-785332 1 i dry pt. (33.6003125 cu.in.) = .550599 1 I dry qt. (67.200625 cu. in.) = 1.101198 1 ipk. (8 dry qt., 537.605 cu. in.) = 8.80958 1 I bu. (4 pk., 2150.42 cu. in.) = 35.2383 1 t firkin (9 gallons) = 34.06799 1 I liter = .264178 gal. = 1.05671 liq. qt. = 33.8147 fl. oz. = 270.518 fl. dr. I ml = 16.2311 minims. I dkl =■ 18.620 dry pt. = 9.08102 dry qt. :^ 1.13513 Pl^- = -28378 bu. MASS MEASURES. Avoirdupois weights. 1 grain = .064798918 g I dram av. (27.34375 gr.) = 1.771845 g I oz. av. (16 dr. av.) = 28.349527 g I pd. av. (16 oz. av. or 7000 gr.) = 14-583333 oz. ap. (5) or oz. t. = 1.2152778 or 7000/5760 pd. ap ort. = 453-5924277 g I kg = 2.204622341 pd. av. I g = 15-432356 gr. = -5643833 av. dr. = -03527396 av. oz. I short hundred weight (100 pds.) = 45-359243 kg I long hundred weight (112 pds.) = 50.802352 kg I short ton (2000 pds.) = 907.18486 kg I long ton (2240 pd.) = 1016.04704 kg I metric ton = 0.98420640 long ton = 1.1023112 short tons Troy weights. I pennyweight (dwt, 24 gr.) = 1.555174 g: gr., oz., pd. are same as apothecary Apothecaries' weights. I gr. = 64.798918 mg I scruple O, 20 gr.) = 1.2959784 g I dram (3,3 9) = 3-8879351 g loz. (5,8 3) = 31.103481 g 1 pd (125, 5760 gr.) = 373.24177 g I g = 15-432356 gr. =0.7716189 = 0.2572059 3 = .03215074 5 I kg = 32.150742 5 = 2.6792285 pd. 1 metric carat = 200 mg = 3.0864712 gr. U. S. I dollar should weigh 12.5 g and the smaller silver coins in proportion. Appendix 883 TABLE 188. Conversion of Degrees Centigrade into Degrees Fahrenheit, or vice versa. Formula Foimula: F.=C.x|.+32 C.=iF.— 32x ^ 9 Degrees Degrees Degrees Degrees Centrigrade Fahrenheit Centrigrade Fahrenheit -17-78 24 75-2 -15 5-00 25 77-0 -10 1400 30 86-0 - 5 23-00 35 95 3200 37-78 1000 1 33-8 400 1040 2 35-6 45 1130 3 37-4 50 122-0 4 39-2 55 131-0 5 410 60 1400 6 42-8 65 1490 7 44-6 70 1580 8 46-4 75 167-0 9 48-2 80 1760 10 50-0 85 185-0 11 51-8 90 194-0 12 53-6 95 203 13 55-4 100 212-0 14 57-2 105 221-0 15 590 110 2300 15-56 600 115 239-0 16 60S 120 248-0 17 62-6 125 257-0 18 64-4 130 266-0 19 66-2 135 275-0 20 68-0 140 284-0 21 69-8 145 293-0 22 71-6 150 302-0 23 73-4 DIFFERENCE TABLE Degrees F into C C into F 1 •56 1-8 2 1-11 3-6 3 1-67 5-4 4 2-22 7-2 5 2-78 9-0 6 3-33 10-8 7 3-89 12-6 8 4-44 14-4 9 5-00 16-2 10 5-56 180 884 Appendix TABLE 189. Alcohol table for calculating the percentages of alcohol in mixtures of ethyl alcohol and water from their specific gravities. (Calculated by U. S. Bureau of Standards from its experimental results).^- Specific Alcohol 1 Specific Gravity 20° C. Alcohol Gravity 20° C. Per Cent Per Cent Grams Per Cent Per Cent Grams by Vol. by Per by Vol. by Per 4° at 20° C. Weight 100 cc. 4° at 20° C. Weight 100 cc. 0.99823 0.00 0.00 0.00 0.97704 10.75 13.53 13.22 99785 0.25 0.20 0.20 0.97678 17.00 13.74 13.42 . 99748 0.50 0.40 0.40 0.97650 17.25 13.94 13.02 0.99711 0.75 0.59 0.59 0.97024 17.50 14.15 13.81 0.99675 1.00 0.79 0.79 0.97596 17.75 14.35 14.01 0.99638 1.25 0.99 0.99 0.97570 18.00 14.56 14.21 0.99601 1.50 1.19 1.19 0.97542 18.25 14.77 14.41 . 99564 1.75 1.39 1.38 0.97517 18.50 14.97 14.60 99528 2.00 1.59 1.58 0.97490 18.75 15.18 14.80 0.99492 2.25 1.79 1.78 . 97464 19.00 15.39 15.00 0.99456 2.50 1.98 1.97 0.97438 19.25 15.59 15.20 0.99420 2.75 2.18 2.17 0.97412 19.50 15.80 15.39 . 99384 3.00 2.38 2.37 0.97386 19.75 16.01 15.59 . 99348 3.25 2.58 2.57 0.97359 20.00 10.21 15.79 0.99313 3.50 2.78 2.76 0.97333 20.25 10.42 15.99 . 99278 3.75 2.98 2.96 0.97306 20.50 10.03 16.18 0.99243 4.00 3.18 3.16 0.97278 20.75 16.84 16.. 38 . 99208 4.25 3.38 3.36 . 97252 21.00 17.04 16.58 0.99174 4.50 3.58 3.55 0.97227 21.25 17.25 16.77 0.99140 4.75 3.78 3.75 0.97199 21.50 17.40 10.97 99106 5.00 3.98 3.95 0.97172 21.75 17.07 17.17 0.99073 5.25 4.18 4.14 0.97145 22.00 17.88 17.37 . 99040 5.50 4.38 4.34 0.97118 , 22.25 18.08 17.50 99006 5,75 . 4.58 4.54 0.97091 22.50 18.29 17.76 . 98973 6.00 4.78 4.74 . 97063 22.75 18.50 17.96 0.98941 6.25 4.99 4.93 0.97036 23.00 18.71 18.16 . 98908 6.50 5.19 5.13 0.97007 23.25 18.92 18.35 0.98876 6.75 5.39 5.33 0.97982 23.50 19.13 18.55 0.98845 7.00 5.59 5.53 0.90952 23.75 19.33 18.75 0.98813 7.25 5.79 5.72 0.96925 24.00 19.55 18.94 0.98781 7.50 5.99 5.92 0.96896 24.25 19.75 19.14 98750 7.75 0.19 6.12 0.96869 24.50 19.96 19.34 0.98718 8.00 6.40 6.32 0.96840 24.75 20.17 19.54 . 98688 8.25 6.60 6.51 0.96812 25.00 20.38 19.73 98658 8.50 0.80 6.71 0.90783 25.25 20.59 19.93 0.98627 8.75 7.00 0.91 0.96755 25.50 20.80 20.13 0.98596 9.00 7.20 7.10 0.96727 25.75 21.01 20.33 . 98566 9.25 7.41 7.30 0.96099 26.00 21.22 20.52 . 98537 9.50 7.61 7.50 . 96669 26.25 21.43 20.72 0.98506 9.75 7.81 7.70 0.96641 20.50 21.64 20.92 0.98476 10.00 8.02 7.89 0.96612 20.75 21.85 21.12 98446 10.25 8.22 8.09 0.90583 27.00 22.07 21.31 0.98416 10.50 8.42 8.29 . 96553 27.25 22.28 21.51 0.98385 10.75 8.62 8.49 . 96525 27.50 22.49 21.71 0.98356 11.00 8.83 8.68 0.96495 27.75 22.70 21.91 98326 11.25 9.03 8.88 0.96465 28.00 22.91 22.10 0.98296 11.50 9.23 9.08 0.90430 28,25 23.12 22.30 0.98267 11.75 9.44 9.28 0.90400 28,50 23.33 22.50 0.98238 12.00 9,64 9.47 0.90375 28.75 23.55 22.69 0.98208 12.25 9.84 9.67 0.96346 29.00 23 . 76 22.89 0.98180 12 . .50 10.05 9.87 0.96310 29.25 23.97 23.09 0.98150 12.75 10.25 10.07 0.90285 29.50 24.18 23.29 0.98122 13.00 10.46 10.26 . 90255 29.75 24.39 23.48 . 98094 13.25 10.60 10.40 0.90224 30.00 21.61 23.68 0.98066 13.50 10.86 10.66 0.90193 30.25 24.82 23.88 . 98037 13.75 11.07 10.85 0.90103 30.50 25.04 24.08 . 98009 14.00 11.28 11.05 0.96132 30.75 25.25 24.27 0.97980 14.25 11.48 11.25 0.96100 31.00 25.40 24.47 , 97953 14.50 11.68 11.44 . 96069 31.25 25.67 24.67 0.97924 14.75 11.89 11.64 0.96030 31.50 25.89 24.80 0.97897 15,00 12.09 11.84 . 96005 31.75 26.10 25 . 00 0.97868 15.25 12.30 12.04 0.95972 32.00 20.32 25.20 0.97841 15.50 12.50 12.23 95939 32.25 20.53 25.40 0.97813 15,75 12.71 12.43 0.95900 32.50 20.75 25.04 0.977S() 16,00 12.92 12.03 0.95873 32.75 26.90 25.84 0.97758 10.25 13.12 12.83 0.95839 33.00 27.18 26.05 0.97732 16,50 13.33 13.02 0.95»00 33.25 27.39 26.25 Appendix 885 TABLE 189— Continued. Specific Alcohol Specific Alcohol Gravity Gravity 20° C. Per Cent Per Cent Grams 20° C." Per Cent Per Cent Grains by Vol. by Per by Vol, by Per 4° at 20° C. Weight 100 cc. 4° at 20° C. Weight 100 cc. 0.95771 33.50 27.61 26.44 . 92967 50.25 42.66 39.67 0.95738 33.75 27.82 26.64 0.92918 50.50 42.90 39.86 . 95703 34.00 28.04 26.84 0.92869 50.75 43.13 40.06 0.95669 34.25 28.26 27.03 0.92818 51.00 43.37 40.26 0.95634 34.50 28.48 27.23 0.92768 51.25 43.60 40.46 0.95598 34.75 28.69 27.43 0.92719 51.50 43.84 40.65 0.95563 35.00 28.91 27.63 0.92668 51.75 44.08 40.85 0.95528 35.25 29.12 27.82 0.92617 52.00 44,31 41.05 . 95492 35.50 29.34 28.02 92567 52.25 44,55 41.24 0.95456 35.75 29.56 28.22 0.92516 52.50 44.79 41.44 0.95419 36.00 29.78 28.42 0.92466 52.75 45.03 41.64 0.95382 36.25 29.99 28.61 0.92414 53.00 45.27 41.83 0.95346 36.50 30.22 28.81 0,92363 53.25 45.51 42.03 0.95308 36.75 30.43 29,01 0,92312 53.50 45.75 42.23 0.95272 37.00 30.66 29,21 0,92261 53.75 45.98 42.43 0.95234 37.25 30.87 29,40 , 92209 54.00 46.23 42.62 0.95196 37.50 31.09 29.60 0,92157 54.25 46.46 42.82 0.95158 37.75 31.31 29.80 0,92105 54.50 46.71 43.02 0.95120 38.00 31.53 29.99 , 92053 54.75 46.94 43.22 0.95081 38.25 31.75 30.19 0,92000 55.00 47.19 43.42 0.95043 38.50 31.97 30.39 0,91948 55.25 47.43 43.61 0.95003 38.75 32.19 30.59 0,91895 55 , 50 47.67 43.81 0.94964 39.00 32.42 30.79 0.91842 55.75 47.91 44.01 0.94926 39.25 32.63 30.99 0.91789 56.00 48.16 44.20 0.94885 39.50 32.86 31.18 0.91736 56.25 48.40 44.40 0.94845 39.75 33.08 31,38 0.91683 56.50 48.64 44.60 0.94805 40.00 33.30 31,57 0.91629 56.75 48.89 44.80 0.94765 40.25 33.52 31.77 0.91575 57.00 49.13 44.99 0.94725 40.50 33.75 31.97 0.91521 57.25 49.38 45.19 0.94684 40.75 33.97 32.17 0,91467 57.50 49.62 45.39 0.94643 41.00 34.19 32.36 0,91414 57.75 49.87 45.59 0.94602 41.25 34.41 32.56 0.91359 58.00 50.11 45.78 0.94560 41.50 34,64 32.76 0.91304 58.25 50.36 45.98 0.94519 41.75 34.86 32.96 0.91250 58.50 50.60 46.17 0,94477 42.00 35.09 33.15 0.91194 58.75 50.85 46.37 0.94435 42.25 35.31 33.35 0.91138 59.00 51.10 46.57 0.94393 42.50 35.54 33.55 0.91082 59.25 51.35 46.77 0.94351 42.75 35.76 33.75 0.91027 59.50 51.60 46.97 0.94308 43.00 35.99 33.94 0.90971 59.75 51.84 47.16 0.94265 43.25 36.21 34.14 0.90915 60.00 52.09 47.36 0.94222 43,50 36.44 34.34 . 90859 60,25 52.34 47.56 0.94179 43.75 36.66 34.53 , 90803 60.50 52.59 47.76 0.94135 44.00 36.89 34.73 0,90747 60.75 52.84 47.95 0.94091 44.25 37.12 34,93 0.90690 61.00 53.09 48.15 . 94046 44 . 50 37.35 35,13 , 90633 61.25 53.34 48.35 0.94002 44.75 37 . 57 35.32 0,90577 61.50 53.60 48.55 0.93957 45.00 37.80 35.52 0.90520 61.75 53.85 48.74 0.93912 45.25 38.03 35 . 72 . 90463 62.00 54.10 48.94 0.93867 45.50 38.26 35.92 . 90406 62.25 54.35 49.14 0.93822 45.75 38.49 36.11 . 90349 62.50 54.60 49.33 0.93776 46.00 38.72 36.31 0.90290 62.75 54.86 49.53 0.93730 46.25 38.95 36.51 0,90233 63.00 55.11 49.73 0.93684 46.50 39.18 36.70 0.90175 63.25 55.37 49.93 0.93638 46.75 39.41 36.90 0.90117 63.50 55.62 50.12 0.93591 47.00 39.64 37.12 0.90059 63.75 55.88 50.32 0.93545 47.25 39.87 37.30 0.90001 64.00 56.13 50.52 0.93498 47.50 40.10 37.49 0.89942 64.25 56.39 50.72 0.93451 47.75 40.33 37.69 0.89884 64.50 56.64 50.91 0.93404 48.00 40.56 37.89 0.89825 64.75 56.90 51.11 0.93356 48,25 40.79 38.09 0.89767 65.00 57.16 51.31 0.93308 48,50 41.03 38.29 0.89708 65.25 57.41 51.51 0.93260 48.75 41,26 38.48 0.89649 65.50 57.67 51.71 0.93213 49.00 41,49 38.68 0.89590 65.75 57.93 51.90 0.93164 49 . 25 41.72 38.87 0.89531 66.00 58.19 52.10 0.93116 49.50 41.96 39,07 0.89471 66.25 58.45 52.30 0.93066 49.75 42.19 39,27 0,89411 66.50 58.71 52.49 0.93017 50.00 42,43 39,47 0,89351 66.75 58.97 52.69 886 Appendix TABLE 189- -Continued. Specific Alcohol 1 Specific Alcohol Gravity 20° C. Per Cent Per Cent Grams Gravity " 20° C. Per Cent Per Cent Grams bv Vol. by Per by Vol. by Per 4° at"20° C. Weight 100 cc. 4° at 20° C. Weight 100 cc. 0.89291 67.00 59.23 52.89 0.84859 83.75 77.90 66.11 0.89231 67.25 59.49 53.08 0.84756 84.00 78.20 66.30 0.89171 67.50 59.75 53.28 0.84713 84.25 78.50 66.50 0.89110 67.75 60.02 53.48 . 84639 84.50 78.80 66.70 . 89050 68.00 60.28 53.68 . 84564 84.75 79.11 66.90 88989 68.25 60.54 53.87 0.84489 85.00 79.41 67.09 . 88928 68.50 60.80 54.07 0.84413 85.25 79.75 67.29 . 88867 ■ 68 . 75 61.07 54.27 . 84339 85.50 80.02 67.49 . 88805 69.00 61.33 54.47 . 84263 85.75 80.33 67.69 . 88744 69.25 61.60 54.66 0.84188 86.00 80.63 67.83 . 88682 69.50 61.86 54.86 0.84110 86.25 80.94 68.08 0.88621 69.75 62.13 55.06 . 84034 86.50 81.25 68.28 0.88558 70.00 62.39 55.25 0.83957 86.75 81.56 68.48 0.88496 70.25 62.66 55.45 0.83881 87.00 81.87 68.68 0.88434 70.50 62.92 55.65 . 83802 87.25 82.18 68.88 88372 70.75 63.20 55.85 0.83725 87.50 82.49 69.07 88309 71.00 63.46 56.04 0.83647 87.75 82.80 69.27 . 88246 71.25 63.74 56.24 . 83569 88.00 83.12 69.46 0.88183 71.50 64.00 56.44 0.83489 88.25 83.43 69.66 88120 71.75 64.27 56.64 0.83410 88.50 83.75 69.86 . 88056 72.00 64.54 56.83 0.83331 88.75 84.06 70.05 . 87993 72.25 64.82 57.03 0.83251 89.00 84.39 70.25 . 87929 72 . 50 65.08 57.23 0.83170 89.25 84.70 70.45 87865 72.75 65.36 57.42 0.83089 89.50 85.03 70.65 . 87800 73.00 65.63 57.62 0.83008 89.75 85.34 70.84 0.87737 73.25 65.91 57.82 0.82925 90.00 85.67 71.04 0.87672 73.50 66.18 58.02 0.82843 90.25 85.99 71.24 0.87607 73.75 66.45 58.21 0.82759 90.50 86.32 71.44 . 87542 74.00 66.72 58.41 0.82674 90.75 86.64 71.63 0.87478 74.25 67.00 58.61 . 82590 91.00 86.97 71.83 87413 74.50 67.27 58.81 0.82505 91.25 87.30 72.03 . 87347 74.75 67.55 59.01 0.82419 91.50 87.63 72.23 . 87282 75.00 67.83 59.20 . 82332 91.75 87.96 72.42 0.87217 75.25 68.11 59.40 0.82246 92.00 88.29 72.62 0.87151 75.50 68.38 59.60 0.82159 92.25 88.63 72.82 . 87084 75.75 68.66 59.79 0.82071 92.50 88.96 73.02 0.87019 76.00 68.94 59.99 0.81982 92.75 89.30 73.21 . 86952 76.25 69.22 60.19 0.81893 93.00 89.64 73.41 . 86885 76.50 69.50 60.39 0.81803 93.25 89.98 73.61 0.86818 76.75 69.78 60.58 0.81711 93.50 90.32 73.80 0^86751 77.00 70.06 60.78 0.81620 93.75 90.67 74.00 . 86684 77.25 70.35 60.98 0.81526 94.00 91.01 74.20 0.86617 77.50 70.63 61.18 0.81432 94.25 91.36 74.40 0.86548 77.75 70.91 61.37 0.81337 94.50 91.71 74.59 . 86480 78.00 71.19 61.57 0.81241 94.75 92.06 74.79 0.86412 78.25 71.48 61.77 0.81144 95.00 92.41 74.99 '. 86344 78.50 71.76 61.96 0.81047 95.25 92.77 75.19 0.86275 78.75 72.05 62.16 . 80949 95.50 93.12 75.38 . 86206 79.00 72.34 62.36 . 80849 95.75 93.48 75.58 0.86137 79.25 72.63 62.56 . 80749 96.00 93.84 75.78 . 86069 79.50 72.91 62.75 0.80648 96.25 94.21 75.98 85999 79.75 73.20 62.95 . 80545 96.50 94., 57 76.17 . 85928 80.00 73.49 63.15 0.80442 96.75 94.94 76.37 . 85859 80.25 73.78 63.34 . 80337 97.00 95.31 76.57 85789 80.50 74.06 63.54 0.80230 97.25 95.68 76.76 0.85719 80.75 74.36 63.74 0.80122 97 . .50 96.05 76.96 0.85648 81.00 74.65 63.94 0.80012 97.75 96.44 77.16 . 85578 81.25 74.94 64.13 0.79900 98.00 96.82 77.36 . 85507 81.50 75.24 64.33 . 79786 98.25 97.20 77.55 . 85436 81.75 75.53 64.53 0.79672 98.50 97.59 77.75 . 85364 82.00 75.82 64.73 0.79553 98.75 97.98 77.95 . 85293 82.25 76.12 64.92 . 79432 99.00 98.38 78,14 '. 85222 82.50 76.41 65.12 0.79311 99.25 98.78 78.34 0.85151 82 . 75 76.71 65.32 0.79188 99.50 99.18 78 . 54 . 85077 83 00 77.01 65.51 0.79062 99.75 99.59 78.74 . 85006 83.25 77.30 65.71 0.78934 100.00 100.00 78.93 0.84933 83.50 77.60 65.91 ' Appendix 887 05 iH PQ H — ' 03 o 53 25, S, ?, ?i S, '^ 03 rt c3 "rt 03 cS c3 "S c3 c3 03 O (M ■* O t^ 10 10 CD 1— ir-i(MC^Tf.eou:>oo ^ rt -H rt (M (M C^J t. o ■IS 0^1 u. 03 x; :s: ^, « W 03 CL^ CS rr" ^ T3 el h-J ^ C -H 03 c . Oi -H rt< |>. 1— I -t< 00 1-H 1-H .— I C^ (M CM O O -ti 10 CO t^ (M r--. CO CO Tt< Ttl o t^ CO CO 10 10 OCOCMCOOCOIMCOOCO(MOOOOOM r-< o Tti (M .-H CO O T-i (M CO Tfi lO O-l CD. CO UO' t>- 00 o iM TjH tv. as — I 10 00 (M CO CO ipcp-. CD CD 00 ^ CD CO -H " " O CO CD o (— , 10 CD ■* 00 r^ CO rt< 01 U<) CD •0 r^ " CM CO TtH lO •n< CD CD i^ 00 di ■^■^OOt^-i-HOlCMO C^l 05 -H t^ c^i t^ 10 CO ^ CO CD 01 C^J CM CM CM iOiOt~-COCO>0 001i-Ht--.iot^CMOr-( OCDCOC-lO'lCOCDOliO'-HOiOOOS'^Tti '-irtC^ico-*iocor^Oi'-HCM'*cD05^ t^ CO »c t^ o 00 t^ t^ 00 ^ CM CO rt< 10 l>- CO o-i >— I .— 1 Tf t>. CO ■* 05 10 CM o o o 00 Oi "-H CO 10 CD 03 o o c^i vn —I CO CM CM S!%29SSSS25£J2P<^ooooTf— ii— iCM'ticOOiO'^OOcDiOiS rtrtCMCOTfiiOCOt^OOO^COTticOOOO 1: O O 00 "O CM CD t^ -H 10 -H 00 10 >— ir^CMCMCOrJHiOCO 00 C5 '-^ CM '0OOCMOCMOOt~-I~-OO>0OCMOC) t>.oocM030'*c^icot^iot^c^)OCMt>.Soo Q0'-lCM05>0l^t^TtH00O05CDO'-^'05lO00 i00iC0l--.C0OC0-^0-)0)'— iCM^CDOOC'icS •-H— iCMC>1C0-<*<<0C0(^C0C5O'HC0^ -"So w C3 q; Or; <^ lO^'OOCDOCDOCOOCOOCOOCOOcO CMC^lCOrft'S'iOiOCOCOt^t^OOOobsOlOO tn K>^ 3 ^ n >J &, -w OJ '^ S 888 Appendix TABLE 191. Composition of Milk from Different Mammals, No. of Samples Water Total Solids Fat Sugar Nitrogenous Constituents Kind of Milk Casein Albumin Ash Cow 87.65 87.43 85.71 80.82 90.06 89.23 90.12 82.84 87.13 86.55 84.04 86.13 62.00 65.88 68.14 90.43 77.00 82.10 69.50 48.67 70.18 12.35 12.57 14.29 19.18 9.94 10.77 9.88 17.76 12.87 13.45 15.96 13.87 38.00 34.12 31.86 9.57 23.00 17.90 30.50 51.33 29.82 3.70 3.78 4.78 6.86 1.09 1.92 1.37 7.96 2.87 3.15 4.55 4.80 23 . 64 19.73 20.58 4.51 9.26 3.33 10.45 43.76 19.40 4.50 6.21 4.46 4.91 6.65 5.69 6.19 4.86 5.39 5.60 3.13 5.34 2.50 2.61 7.18 "s'.ii' 4.91 1.95 none 2.60 1.02 3.20 4.97 1.89 2.63 .79 4.16 3.87 3.90 7.23 3.03 10.44 10.35 3.45 Not rep 4.15 3.12 15.54 Not rep 9.43 .60 1.26 1.09 1.55 1.89 2.63 1.06 4.16 3.87 3.90 7.23 3.03 10.44 10.35 3.45 orted 5.57 5.96 15.54 orted 9.43 .70 200 200 32 31 3 25 60 4 1 9 1 .30 76 .89 .31 .53 .47 .78 .74 .80 1.05 Zebra .70 1.42 2 2 1.43 .65 Bitch 46 .91 Cat .58 Rabbit .... 2.56 .46 Whale .99 REFERENCES. 1 Atomic Weight. Report of International Committee on Atomic Weights, Journal Ameri- can Chemical Society 1921, page 1751. Valency Smithsonian Physical Tables 1921, p. 110-111. Specific Gravity — Smithsonian Physical Tables 1921, p. 110-111. Atomic Heat — Smithsonian Physical Tables 1921, p. 226. Specific Heat — Smithsonian Physical Tables 1921, p. 226. Atomic Heat — Smithsonian Physical Tables 1921, p. 226. Thermal Conductivity — Smithsonian Physical Tables 1921, p. 226. Linear Coefficient of Expansion — Smithsonian Physical Tables 1921, p. 218 and 219. Melting Point — Smithsonian Physical Tables 1921, p. 198. Boiling Point — Smithsonian Physical Tables 1921, p. 199. Van Nostrand's Chemical Annual 1907. " Richmond H. Droop. Dairy Chemistry 1899, p. 353. 8 Courtesy Taylor Instrument Co. Catal. Par. 1500-1600, p. 20. * Leland, Walter S. The Steam Engine, Technical World Magazine, Chi- cago, 1908, pp. 88 and 89. 5 Smithsonian Physical Tables 1921, p. G. " Smithsonian Physical Tables 1921, p. 6. ' Smithsonian Physical Tables 1921, p. 7. 8 Smithsonian Physical Tables 1921, p. 8. ^ Smithsonian Physical Tables 1921, p. 9. '» Smithsonian Physical Tables 1921, p. 10. "Smithsonian Physical Tables 1921, p. 11. 1- Official and Tenatinve Methods of analysis of the Ass'n of Official Agr. Chemist. 13 Courtesy the Pfaudler Co., Rochester, New York. Index of Proper Names Adams, 14 American Public Health Assn., 552 Anderson, J. F.. 521 Arrhenius, S-, 665 Association of Official Agricultural Chemists, 568, 570, 572. 576, 579. 614, 619, 620, 632. 641, 648, 884, 886 Atkins, 656 Atwater. W. O.. 432 Ayers, S. H.. 521. 608 B Babcock & Wilson Co.. 704 Baer, A. C. 443. 799 Railcy, 5, 2i2 Baker, H. A.. 769 Baker, J. C, 523, 660, 667, 678 Balton, E. R., 39 Barber, 525 Barnett. G. D., 502 Barthel. C, 32, 38, 656 Bartoli, 445 Beau, 32, 595 Bellis, B.. 593 Berrv, J. L., 498 Bicsterfeld, 43 Biprelow, W. D., 40, 58, 59, 590, 666 BoRue, R. H„ 283 Bordas. 592 Bosworth, A. W., 16 Bothell, F. H. 289 Breed, R. S., 498, 500, 507, 515, 519 523 Brew, J. D., 498, 515. 519 Browne, C. A., 19. ii Bryant. A. P., 432 Buchanan, 524 Bundy, F. M., 49 Bunsen, 770 Burr, 2,2 Butterman, S-, 573 California and. Southwestern States Tee Cream Manufactures Assn., 800 Cathcart, P. H., 666 Cavanaugh. 7i7 Chapman, H. S., 502 Chesney, 525 Clark, A. W., 646 Clark, M. W., 498, 676. 682 Commission on Milk Standards. 519 Comittee on, Food and Drug Definitions and Standards, 810 Leeral Standards and Score Cards, 800 Standard ^^lethods for the Bac- teriological Examination of Milk, 498 Standard Methods of Bacterio- logical Analysis, 498 Statistics of Milk and Cream. 828 Technique of the Society of American Bacteriologists, 521 Congden, L. A., 633 Conn, H. W., 551 Cook, A. A., 634 Coolidge, L. H., 764 Cromley, R. H., 286 Cross, J. A., 145, 146, 172, 176, 416 Cusick, J. T.. 30 Cutler, T. H., 446 Dalbarg, A. O., 574, 607 Dcarstyne, R. S.. 506 Donauer. M., 858 Dottercr. W. D., 498, 507 DuBois. L., 646 Duhrunfaut. 23. 294 Duckwall, E. W.. 495 E Eckels, C. H., 559, 764 Erf, O., 150, 856 Evenson, O. L- 43, 609 Fitzgerald, 40. 58, 59 Fleischman, 56 Frandsin, J. H., 800 Frohring. W. O., 55, 450, 451, 525, 528, 529, 550 Frost, W. D., 520 [891] 892 IndKx of Proper Names Garner, H. S., 607 Gill, A, H., 704 Gordon, P., 38 Gottlieb, E., 36 Govers, 40 Grimmer, 656 Grinrod, 40 Groth, P., 289 H Hall, F. H.. 549 Hall, T., 299, 461 Hamilton, Dr., 715 Hammer, B. S.. 275, 294, 445, 650 Hanna, E. C, 455 Harrison, 588 Hart, E. B., 549, 569, 726. 7iZ, 735 Hastings, E. G., 522 Heineman, P., 656 Heller, 287 Hess. A F., 862 Hill, H. W., 507 Hoffman, C-, 522 Hubl, 630 Hudson, C. S., 23 Hunziker, O. E., 551, 616 International Committee on Atomic Weights, 866-869 Tackson, D, D., 522 Johnson, A. R., 275. 445, 650 Johnson, W. T.. 608 K Kirchner, W., 21 Klein, L. M., 60, 61, 287 Kropat, K.. 39 Lang, 2)7 Latzer, R. L., 72,7 I.each, 39 Eeland, W. S., 708. 874, 875 Liedel, H. J., 23, 172. 294. 578, 857 Lubs, H. A., 498, 682 M Mack, E., 23, 294 Marshall, 15 McCrudden. F. H.. 683 McCullum, 1-:. v., 30 McElroy, 590 McGill, A., 442 Mclnerney, T. J., ZZ, 52, 563, 727 Medalia, L. S., 503 Melick, C. W., 486 Meniere, G. J., 39 Mojonnicr, J. J., 44, 58, 59, 77. 302, 432 Mojonnier, T.. 2?,, 40, 289, 302, 432. 664, 717, 730, 756 Morse, J. B., 455 Mortensen, M., 443, 800 Palmer, L. S.. 764 Patrick, Dr., 39 Pearson, R. A., 142 Penfold, 525 Peterson, R. W.. 302 Pfaudler Co., 887 Poole, 704 Popp, M.. 2>7 Prucha, M. J., 521 R Rackowski, 592 Rice. F. E., 32, 726 Richmond, H. D., 39, 56, 275, 656, 883 Robinson, R, H., 611 Rogers, T,. A., 735 Rohrig, 37 Rose, B., 36 Rothenfusser, 591 Ruehle, G. L. A.. 521 Russell, H. J., 32 Schreib. H., 36 Schroeder, M. C, 521 Sebelien, 29 Shaw, 559 Sherman, J. M.. 498, 522 Skinner, W. W., 283 Slack. F. H., 498 Smithsonian Physical Tables, 866- 869, 876-882 Snow, 708 Soillard. E., 23 Soldner, 29 Sommer, H. H., 726, 732, 735 Sorensen, 502 Stocking, 498. 510, 549, 656 Stracciati, 445 Supplee, G. C, 30, 593 Taylor, G. B., 822 Taylor Instrument Co., 865 Indkx of Prope;r Namcs 893 Telling- Belle Vernon Co.. 55, 550 Thomas, H. N., 822 Thomsen, 38 Titus, 60, 61 Tonney, F. O., 521 Tracy, D. H., 302 Traube, 33 Travis, R. P., 296 Troy, H. C, 13, 53, 77, 615, 622 Van Nostrand. 866 Van Slyke. L. L.. 16, 21. 32, 549 576, 660, 667, 678 W Walker, W. O., 569 Washburn, R. AI., 443. 457, 800 Weibull, 37 Wells, H. L., 76 Werner, P., 515 Whitaker, G M., 772 White, W. B.. 13. 14. 583 Wilcox, E. v.. 488. 613 Williams. O. E., 289 Winton, A., 439, 628 Woodman, A. G., 634 Zollcr, H. F., 289 Index of Subjects Acid, acetic, 6 apparent, in milk, 32 butyric, in fat, 19 caproic, in fat, 19 caprylic, in fat, 19 carbonic, 30 citric, in milk, IS, 32, 31 hydrochloric, 6, 7, 30 lactic, in milk, 26-28 lauric, in fat, 19 myristic, in fat, 19 nitric, 6 oleic, in fat, 19 oxalic, 6 palmitic, in fat, 19 phosphoric, 30, 2>2 rosolic, 6 stearic, in fat, 19 sulphuric, 6, 30 tests, 601 Acidity, of evaporated milk, 765 of various dairy products, 604 Agar, composition of beef extract, 5 501 preparation of. 503-506 Albumin, 15, 28, 29, 575. 663 composition of, 29 determination of. in milk. 575 preparation of pure. 663 uses of. 29 Alcohol, 6, 27, 44-48 amy], 6 ethyl, 6 functions of, in Mojonnier test, purity of. 44 quality of, for Mojonnier test, specific p^ravitv of, 44 table. 884-886" test, for milk. 606 Ammonia, 6 Analysis, of butter, 614-620 of casein, to determine qual 573-575 of cheese, 620-624 of dairy products for thickeners. 633-638 of dairy products for lime, 576-578 of dairy products, 554-683 of dairy products for sugar, 579- 596 of fat for foreign fats, 626-632 of gelatin, 645 to 647 of gmn arabic, 647, 648 of gum tragacanth, 648 of milk for albumin, 575 of milk for ash, 576 of milk for acid. 601-604 of milk for casein, 568-570 of milk for citric acid, 593-596 of milk for lecithin, 592 of milk for nitrogen, 570-572 of milk for preservatives. 609 of milk for skimming and water- ing. 564 of milk chocolate, 572, 573, 632 of salt, 638-641 of vanilla extract, 641-643 of vanilla resins, 644-645 Apparatus, for laboratorj', 4 00. for making l)acteriological tests, plate method. 498 for making bacteriological tests. Breed method. 515 for propagating pure cultures, 531 Argonin, 22 Asbestos, fibre, 7 Ash, composition of, 29 in milk. 29, 576 separation of, from skim-milk, 664 45 44 B Babcock test, 14. 36. 41 composition of fat in. 56 Bacteria, city standards for, in milk and cream. 831. 832 commercial application of. 523 detection of specific, in milk. 522 ity. in dairy products, 80 in milk, 485 [895] 896 Index of Subjects in ice cream mix, when prepared by Mojonnier vacuum pan method, 303 state standards on, content in milk and cream, 822 strain of, recommended for com- mercial uses, 523 types of, found in milk, 485-498 Bacteriological counts, apparatus for making, plate method, 498 apparatus for making. Breed method, 515 collection of samples, for, 498-500 composition of media for making, 500 incubation temperatures for, 514 macroscopic colony, Petri plate method, 500-515 " microscopic, Breed method, 515- 521 preparation of media for making, 503-506 reports of, plate method, 509 sources of error, in making, plate method, 508 verification and research meth- ods, 521 Balance, analytical, IZ care and use of, 72-77 chainoniatic, 67, 74-77 oscillations of, 76 specific gravity chainomatic, 554, 556, 557 weights for, 74 Westphal, 59 Boiling point, relation of vacua and rate of evaporation to, 685 Bottle, composite samples, 80 specific gravity, 555 Breed method for making bacterio- logical counts, 515-521 Brine, temperature of, for freezing ice cream, 457 pressure of, for freezing ice cream, 457 Burettes, automatic for Alojonnier test, 66 Butter, analysis of, 614-620 determination of moisture in, 614 determination of salt in, 615-619 determination of fattj- acids in, 619 fat test for, 110 flow sheet of, manufacture, 850 sampling, 88 score card for, 790-792 solids test for, 128 specific heat of, 654, 655, 656 temperature to churn and hold, 856 use of culture, in making, 550 Butterboat, illustration of, 97 directions for weighing with, 97 Butterfat, see fat Buttermilk, condensing in the vacuum pan, 718 definition of, 811 fat test for, 106 sampling, 89 score card for, 793 total solids test for, 124 Buttermilk, condensed fat test for, 107 relation specific gravity, temper- ature and composition in, 438 Buttermilk (culture), apparatus for propagating cul- ture, for, 532 application of pure cultures in the manufacture of, 543 directions for making, 544-546 flow sheet of, manufacture, 854 preventing wheying-off in, 547 quantity of culture to use in making, 543 temperature to hold, 855 temperature to inoculate skim- milk in making, 855 temperature to incubate in mak- ing, 855 Butyrin, 15, 19 Calcium citrate, in evaporated milk. 761-764 Calories, in ice cream, 275, 278 Cane sugar, see sucrose Capacity, of vacuum pans, 689, 690 of cylindrical tanks, 887 Caprinin, 15. 19 Caproin, 15, 19 Caprylin, IS. 19 Indkx of Subjects 897 Caramel, composition of, for use in ice cream, 287 Cards, score, see score cards Casein, as a food, 22 composition of, 21 condition of, in milk, 21 determination of, in milk, 568-570 determination of, in milk choco- late, 572 determining quality of, 573-575 t1ow sheet of, manufacture, 854 precipitation of, 21, 22 preparation of, pure, 660-663 separation of, 21 uses of, 22 Certified milk, score card for, 784- 786 Cheese, analysis of, 620-624 ash in, 622 dclinition of and standards for, 813-815 determination of acidity in, 622 determination of salt in, 624 distribution, of water in, 89 fat test for, 110, 621 flow sheet of, manufacture, 853 moisture in, 89. 621. 622-624 sampling', 89 score card for, 794-798 solids test for, 127 temperature to cure and hold, 856 use of culture in making, 548-550 Chemical constants of the elements, 866-869 Chemical properties, of ice cream mixes. 272-300 of milk. 12-33 Chocolate, composition of, 438, 439 Citric acid, crystals, 32 determination of. in milk, 593, 31. ?>2 determination of. in milk powder. 594 determination of, in sweetened condensed milk. 594 separation of, 664 City standards, 828-848 Coal, consumption, relation to steam production, 703, 704 Cocoa, composition of, 439, 440 fat test for, 110 nibs. 440, 439 sampling, 92 shells, 439, 440 solids test for, 110 Cocoa syrup, composition for use in ice cream, 287 Coagulation, point of, in evapor- ated. 72S-72,7, 752-754 Composite samples, bottles for, 80 care of, 84 of cream, 85 definition of, 83 for standardizing evaporated milk. 164 for standardizing sweetened con- densed milk, 222 for standardizing various milk products, 131 frequency of testing, 84 instruments for taking. 81-83 preparing for testing, 85 preservatives for, 84 water heater for, 85 Composite test liquid, 84 Composition, of cocoa, cocoa nibs and cocoa shells, 440 of fruits and flavors for ice cream, 287, 288 of ice cream mixes, 272-432 of ice cream mix as affecting the overrun, 447 of milk, 12, 13-33 of milk from different mammals, 888 of milk chocolate, 440 of miscellaneous milk foods, 441 of products used in ice cream mixes, 313 relation to defects in ice cream, 289-300 suggested, of ice cream mixes, 273 Condenser, on vacuum pan, 688 Condensed buttermilk, relation specific gravity, temper- ature and composition in, 438 fat test for, 107 Condensed milk, see unsweetened condensed milk, Constants, evaporated milk, 165 sweetened condensed milk. 221 fat, 626 of the elements, 866-869 Controller, ^[ojoimier Culture, 531-534 898 IndKx of Subjects Mojonnier Evaporated Milk, 725, 740-747 Coolers, for sweetened condensed milk, 234-238 Cream, acid test for, 601-603 bacteria in, city regulations. 832 city regulations on, 842-848 definition of and standards for, 812 fat test for, 109 flow sheet of manufacture, 853 key to formulas for standardizing, 151 powder, score card for, 809 problems in standardizing, 151- 161 sampling, 83 sample of, composite, 85 score card, 788, 789 specific heat of, 652, 653, 656 standardization of, 142-161 standardization of, by Pearson's method, 144 standardization of, by Cross's method, 146-149 standardization of, by Erf's meth- od, 150 standardizing for fat, in, 144, 147, 148, 149 state standards of bacteria in, 822 sucrate of lime in, 636 table giving composition of. 134- 139 test for remade, 609 total solids test for, 126 Cultures, amount of, to use in making but- termilk. 539, 543 apparatus, for propagating pure, 531 effect of holding, at various tem- peratures, 529-530 factors relating to growth of, 524 jars, 536 media for, 534 pipettes, 538 preparation of, 535-542 quantity of, to add to media, 526- 528 relation of acid development and time of ripening of, 525 score card for, 792 use of, in making baker and pot cheese, 549 use of, in making cottage cheese, 548 use of, in making cheddar cheese, 549 usi' of in making butter, 550 use of, in making ice cream, 548 Culture Controller, Mojonnier, 531- 534 Dairy farms, regulations relating to, 840 Dairy laboratory, 1-9 equipment for, 4-7 location of, 1 plan of. 7-9 Dairy products, analysis of, 554-683 condensing, 705-718 history of fat and total solids test on, 34-61 laboratory for testing, 1-9 microscopical examination of, 484. 515-521 miscellaneous information regard- ing. 849-864 principals of fat and solids test for, 34-61 sampling, 80-92 score cards for, 772-809 standards of, 810-848 standardization of, 130-442 testing, 93-141 Definition of, buttermilk, 811 cheese, 813-815 condensed milk, 811 condensed skim-milk, 811, 812 cream, 812 extracts, 818-822 milk, 810 sugars. 816-817 sweetened condensed milk. 811 Detection of, gums, 634-636 preservatives, 609-613 thickeners, 633-636 Determination of, acidity of cheese, and milk, 601- 604, 622 adulteration of milk, 564-566 albumin in milk, 575 ash in milk, 576 ash in cheese, 622 casein in milk, 568-570 citric acid in milk, 593-596 fat in dairy products, 106-111 of fat in cheese, 621 of fatty acids in butter, 619 foreign fat in milk fat, 626-632 freezing point of milk, 656-660 Indkx of Subjects 899 hydrogen ion concentration, 665- '682 lecithin in milk, 592 h'nie in dairy products, 576-578 melting point of fat, 624-626 milk fat in milk chocolate, 632 moisture in butter, 614 moisture in cheese, 621, 622-624 nitrogen in milk, 570-572 preservatives in milk, 609 quality of casein. 573-575 salt in butter, 615-619 salt in cheese, 624 sediment in milk, 605 specific gravity of dairy products, 554-564 solids in dairj^ products, 120-129 sugar in dairy products, 579-596 viscosity of dairy products, 566 Dextrose, sweetening power of, 286 Directions, for making fat test on Mojonnier Tester, 93-119 for making solids test on Mojon- nier Tester, 120-129 Dishes, for Mojonnier test. 64, 65, n, 78, 79 care of. 79 weighing, 78 influence of temperature on weight of, n Drip sample, 83 Eggs, in ice cream mix, 286 Elements, constants of the, 866-869 Entrainment losses in the vacuum pan, 715 Equipment, for making bacteriological counts, 498 for making culture buttermilk, 532, 544-547 laboratory, 5-7 sweetened condensed milk, 233- 238 Ether, 7, 44-48 function of, in Mojonnier test, 45, 46 purity of, 44 Evaporated milk, action of, on tin and iron, 862 adding sodium bicarbonate before sterilizing, 747, 740 calculating Baume readings of, 176-178 calcium citrate as affecting quality of, 761-764 changing temperature when mak- ing, 748 coagulating point of, 725-737 composite samples of, 164 constants for, 165 Controller, Mojonnier, 725, 740- 747 cooling, 179, 180 definition of and standard for, 811 effect of sterilizing temperatures on the nitrogeneous constitu- ents of: 754 effect of acid content upon the coagulating point of, 726-728 factors influencing color of, 764- 769 factors influencing failure of, to react to sodium bicarbonate, 749, 750 factors influencing heat coagula- tion of. 12S-lp factors influencing quality of, 761- 764 gases in, cans, 769, 770 influence of concentration upon the coagulating point of, 734, 735 influence of freezing temperatures upon, 766 influence of mineral constituents upon the coagulating point of, 730-734 influence products of bacterial growth the coagulating point of, 735 influence of method of forewarm- ing upon the coagulating point of, 736, 11>1 laboratory report for, 169 report blank for standardizing data, 169 relation specific gravity, composi- tion and temperature in, 174- 177 sampling, 87 score card for, 802-804 spoilage of, 760, 761 standardizing, 162-219 standardizing before condensing. 165-167, 192-210 standardizing after condensing, 211-219 standardization tables, 180-190 steam distribution when steriliz- ing, 738, 739 sterilizing equipent for, 719-721 sterilization of, 719-755, 758 900 Index of Subjects temperature to heat and hold, titratable acidity of, 765-766 variations in the coagulating point of, 752-754 viscosity of, 755-760, 767-769 Evaporation, rate of, in the vacuum pan, 685, 686 Extracts, definition of and stand- ards for, 812-822 analysis of, 641-643 Factors, of safetv, in standardizing, 192, 249 Farm inspection, score card for, 778 Farm, regulations relating to scor- ing, 840 Fat, (milk) acids in, 19 color of, 17 composition of, 19, 56 detecting foreign in, 626-632 defects in ice cream due to, 289 estimation of, in milk chocolate, 632 function of, in ice cream, 281 globules, 17, 18 glycerine in, 19. 20 homogenized, 18 microscopical exammation of, 17, 484 melting point of, 19, 624 specific heat of, 654, 655 standards, 824-826. 830 test for butter, 110 test for cocoa, 110 test for cheese, 110 test for condensed milks, 107, 108 test for cream, 109 test for ice cream, 109 test for malted milk and milk chocolate, 110 test for milk powders, 111 test for skim-milk, whey and but- termilk, 106 test for whole milk, 106 Fat constants, 626 Federal standards, 810-822 Flavors, in ice cream mixes, 286, 288 Flasks, Mojonnier, 64 weighing, 96 hanger for, 96 Flow sheets of, butter, 850 casein, 854 cheddar cheese, 853 condensed milk, 851 cream, 850 culture buttermilk, 854 evaporated milk, 851 general, of milk, 849 ice cream, 852 milk chocolate, 854 milk powder, 853, milk sugar, 854 sweetened condensed milk. 851 whole milk, 850 Formaldehyde, 84 Formulas for standardizing cream and milk. Formula 1; Pounds of milk to separate, 153 Formula 2; For lowering fat and solids. 154 Formula 3; For raising fat. 157 Formula 4; for fat, 159 Formula 5; for solids. 160 Formulas for standardizing evapo- rated milk. Formula 6; For lowering fat, 193 Formula 7; For raising fat, 195 Formula 8; For raising fat, 196 Formula 9; For determining fat and solids in a mixed batch, 202 Formula 10; For lowering fat and solids, 205 Formula 11; For lowering fat and solids. 205 Formula 12; For lowering fat, 207 Formula 13; For lowering solids not fat, 209 Formula 14; For raising solids not fat. 212 Formula 15; For using cream and condensed whole milk, 216 Formulas for standardizing sweet- ened condensed milk. Formula 16; Using whole milk and skim-milk, 249 Formula 17; Using cream. 252 Formula 18; Using cream, 255 Formula 19; Using cream, 257 Formula 20; Using sweetened condensed skim-milk, 261 Formula 21; Using unsweetened condensed skim-milk, 263 Formula 22; Using unsweetened condensed whole milk, 266, 267 Formula 23; Amount of sugar to use. 266, 267 Index of Subjects 901 Formulas for standardizing ice cream mixes. Formula 24; For making a de- finite weight in the vacuum oan. 316 Formula 25; For making an in- definite weight in the vacuum pan, 319 Formula 26; For low fat and high solids not fat, 321 Formula 27; Both fat and solids not fat high but the fat in higher ratio, 324 Formula 28; Both fat and solids not fat under standard, 328 Formula 29; Both fat and solids not fat under standard, 332 Freezer, ice cream, speed of, 458 t3^pe of, 456 Freezing point, of ice cream mixes, 275, 278 of milk, 656-660 of sugar on, 275 Fruits, in ice cream mixes, 287, 288 Fuchsin, 7 Galalith, 12 Galactose, 32 Gas, relation of, consumption to steam production, 703, 704 Gases, in evaporated milk, 769, 770 Gauge, Green, 170, 171 Gelatin, analysis of, 645-647 condition of, 281 defects in ice cream due to, 298 function of, in ice cream mixes, 281-284 properties of a good gelatin, 286 relation of, to food value, 283 relation of. to incorporation of air, 281, 282 relation of, to overrun, 462' relation of, to smoothness in ice cream, 283, 284 relation of, to viscosity. 282 variation in qualit}^ of. 284 viscosity of, water solutions of, 282, 283 Glass, heat transmission of. 863 Globules, fat, homogenized. 18 in ice cream, 18 milk. 15. 17, 18 Glycerin, 7 Gums, detection of, 633-636 Gum arabic, analysis, 647 Gum tragacanth, analysis of, 648 H Heat of combustion, in ice cream, 274, 275, 278 Heat of Transmission, of metals, alloj^s and glass, 863 Homogenization of, ice cream mix, 453-456 Hood, for laboratory, 3 Hot well, forewarming and heating in, 705- 706 heating milk in, 737, 738 types of, 699 Hydrochloric acid, 7 Hydrogen ion concentration, 665- 682 Hydrometer, Baume, for evaporated milk, 179 Ice cream, application of cultures in making, 548 available heat of combustion in, 274. 278 cause of sandiness in, 289-298 defects due to composition, 289- 300 defects due to fat, 289 defects due to gelatin, 298 defects due to solids not fat, 289 defects due to sugar, 298 defects due to water, 299-300 factors causing loss in overrun. 460-462 factors influencing overrun in. 447-460 fat globules in. 18 fat globules in homogenized in, 18^ fat test for, 109 flow sheet of manufacture, 852 freezing point of, 275. 278 902 Indkx of Subjects general facts reg'ardinp: overrun in, 443 heat units required to melt. 276 latent heat of, 276 Alojonnier overrun tester for, 463- 475 normal heat of, 276 nutritive ratios of, 276, 278 overrun in, 443-475 percentages of overrun, 274, 277, 278 phases in the freezing- of, 444-447 plans for plant laboratory, 9 prevention of sandiness in, 289-298 ]iroportion of water frozen in, 300 sandiness, in, 289-298 sampling, 87 score card for, 798-801 solids test for, 126 specific heat of. 275, 278 weight of, per gallon, 274, 277, 278 Ice cream mixes, acidity of, as affecting overrun, 450-452 aging of, as affecting overrun, 450-452 amount of, to draw into freezer, 456 available heat of combustion of, 274, 278 bacteria in, when prepared in the vacuum pan, 303 causes of variation of composi- tion of, 272 composition of, as affecting over- run, 447-450 composition of products used in making, 313 compositon ratios of, 273 composition and standardization of, 272-432 eggs as filler in, 286 freezer, type of, 456 freezing point of, 275, 278 function of fat in, 281 function of gelatin, in, 281-284 function of solids not fat in, 281 function of sugar in, 281 importance of pasteurization in making, 292 improvers in, 286 influence of age on viscositv of 273 inlluence of gelatin on viscositv of, 273 influence of solids not fat on vis- cosity of, 273 influence of temperature on vis- cosity of, 273 homogenization of, 453-456 keeping qualities of, when pre- pared in the vacuum pan, 3Q3 methods for compounding, 302- 305, 312-316 Mojonnier vacuum pan method, for preparing, 302-304 nutritive ratios of, 276, 278 raw materials in, 272 specific gravity of, 274, 304 specific heat of, 275, 278 starch, as filler in, 286 steps involved in standardizing, 301 temperature to hold. 855 thirteen compositions of. 273 titratable aciditv of, 274 viscosity of. 273. 277. 452 vitamincs in, 281 weight per U. S. Gallon of, 274 Incubation, period of, when making bacteria, count, 507 temperature of, when making bacteria count, 514 of culture, 540 Inspection of milk, score cards for. 772>-779 Invert sugar, sweetening power of, 285 percentage composition of, 285, 286 K Keys to formula, for cream, 151-152 for evaporated milk, 191-192 ice cream mix, 311, 312 sweetened condensed milk, 248 whole milk, 151, 152 Laboratory, 1-9 apparatus and chemicals for, 4, 7 general plans for, 7-9 lighting for. 3 tables and desks for, 2 ventilation and temperature of, 2 Lactic acid, 21, 22, 26, 27, 32 Lactometer, Board of Health, 558, 560 determining specific gravity by means of, 557-564 Quevenne, 57, 558, 560 Lactose, sec milk sugar Lecithin, 15, 30 (ktermination of. in milk, 592 IndKX of SUBIKCTS 903 Levulose, sweetened power of, 286 Lime in dairy products. 576-378 M Macroscopical colony count, 500-515 Malted milk, composition of, 441 condensing, in the vacuum pan, 718 fat tests for, 110 sampling, 91 solids tests for, 127 Maltose, sweetening power of, 286 Mammals, composition of milk from ditterentv 888 Measures, tables for conversion of, 876-882 Melting point, of milk fat, 624 Metals, action of milk on, 856-863 solubility of, in milk, 858 transmission of heat of, 863 Metallic lactates, amount required to impart taste to water, 857 amount actually dissolved, 861 Micfrcscope, bacteria count bv means of, 515- 520 directions for use of, 476-483 examination of milk fat bv means of. 484 examination of milk sugar b^' means of, 484 names of various parts of, 477 standardization of, 517 use of. in the dairy industrv. 476. 483 Milk, analysis of. 568-572. 575-609 albumin, in, 29 ash. in, 29 bacteriological counts on. 500-521 certilicd, score card for. 784-786 citv regulations relating to. 842- 848 critric acid in, 32 color test for, 609 composite sample of, 83 composition of, from different mammals, 888 composition, variations, in, 12, 13 condensing, in the vacuum pan, 705-715 constituents of. 10-33 constituents, preparation of pure, 660-665 detection of specific pathogens in, 522 distribution of constituents of, 14-15 drip sample of, 83 fat in, 11, 12, 17 fat globules in, 18 fat tests for, 11-20 11 ow sheet of, 849-850 freezing point of, 656-660 gases in, 14 heated tests for, 609 inspection, 77?>-777 key to formulas for standardiz- ing, 151 metallic taste in, 861 mineral constituents of, 29 physical properties of, 10 regulations relating to, 831-834 sampling, 80-87 sediment test for, 605 solubilty of metals in, 858 specific heat of, 652-656 standardization of, 142-159 state standards of, 822 testing for adulteration, 564 testing for acidity in, 601-603 test for solids in, 124 types of bacteria found in. 485-498 unsalable, 834 vitamines in, 31 Milk chocolate, composition of, 440 estimation of milk fat in. 632 fat test for, 110 riow sheet of, 854 sampling, 91 solids test for, 127 Milk, evaporated, see evaporated milk Milkers, regulations relating to, 833 Milk foods, composition of, 441 Milk house, regulations relating to. 837 Milk plants, regulations relating to, 839 Milk powder, fat test for. 111 fiow sheet of, 853 sampling, 91 score card for, 808 solids test for, 128 standardization of, 435-438 temperature to heat and hold, 856 904 Index of Subjects Milk sugar, available heat of combustion of, 275 crystalline condition of, 25, 26, 27 crystallization of, in sweetened cond. milk, 236 decomposition of, 226 determination of, 579-591 form of crystallization of, 289 flow sheet of, manfacture, 854 factors influencing solubility of, 290-298 photomicrographs of, crystals. 236 preparation of pure, 664 microscopical examination of, 484 relation of sandiness in ice cream to, 289-298 solubility of, 23-25, 296 sweetening power of, 286 uses of, 27-28 Milk tester, Mojonnier description of, 64-68 directions for making fat test, using, 93-119 directions for making solids test. using, 120-129 illustrations of, 62-64, 68, 69 operation of, 72-79 wiring for, 72 Milk utensils, regulations relating to, 838 Mineral constituents in milk, 29 Mixers, ice cream batch, 308-310 Mojonnier, fat tests, 43-56 Culture Controller, 531-534 Evaporated Milk Controller, 725, 740-747 Ice Cream Packaging Machine. 286 Ice Cream Overrun Tester, 463- 475 solids test, 56-61 sweetened cond. milk equipment, 235 Tester, 4, 35, 43-61, 62-69. 164 Vacuum Pan, 687 Vacuum Pan, method for making ice cream mixes, 302-304 Viscosimeter, 273 Mojonnier fat test, adding reagents in. 97-98 causes of high and low results when making, 115 directions for, 93-119 for buttermilk, skim-milk, and whey. 106 for cheese, cocoa, butter, malted milk, milk chocolate, 110 for condensed milk, 108 for evaporated milk, 93-106 for ice cream, and cream. 109 for milk, 93 for milk powder, HI for unsweetened cond. milk, 107 precautions in making, 112 Mojonnier Milk Tester, description of parts, 64-68 dimensions of, 68-69 directions for making fat tests on, 93-119 directions for making solids tests on. 120-129 illustrations of. 62-69 operation of, 72-79 power unit of, 70 N Nitrogen, determination of, in milk. 570-572 Nutritive ratios, of ice cream. 276- 278 Oil, relation of. consumption to steam production, 703-704 Olein, 15, 19 Operation of, microscope, 481-483 Mojonnier Culture Controller, 532-543 Mojonnier Evap. Milk Controller. 725. 740-747 Mojonnier Milk Tester, 62-69, 70- 79 Moionnier Overrun Tester, 463- 475 sterilizers. 719-724 vacuum pan. 705-718 Overrun, in ice cream, 280, 443-475 facts regarding, 443 factors influencing proper, 447-460 how to retain, 460 loss in, 460-462 phases in the freezing of ice cream and obtaining, 444-446 proper, 447 standardizing the, 473 'iV\stcr. .Mojonnier. 463-475 Palmatin, 15, 19 Pan, Vacuum, see Vacuum Pan Pasteurization, state standards for, 823 IXDKX OF vSuBjECTS 905 of ice cream mixes, 292 Pepsin, in ice cream mix, 286 Petroleum ether, 44, 48 Physical constants of the elements, 866-869 Physical properties, of ice cream mixes, 272-300 of milk, 10, 11 Pipettes, directions for weighing, 95 Piping, for vacuum pan, 692-693 Plans, for dairy laboratories, 7-9 Plate (Petri) method, for making bacteriological counts, 500-515 Powders, milk, fat test for. 111 sampling, 91 solids test for, 128 standardizing of, 435-438 Power unit, for Mojonnier Milk Tester, 6, 64, 66 Proper,ties, chemical, of milk, 12-33 chemical, of ice cream mixes, 272- 300 physical, of milk, 10, 11 physical, ice cream mixes, 272-300 Proteins, available heat of combus- tion of, 275 R Reagents, for ]\lojonnier Test, 6, 7, 44-48, 98. 99, 106 Regulations, see standards Rennet, in ice cream mix, 286 Rheostats, for Mojonnier Tester, 66 Report blanks, cost, of ice cream mix, 307 laboratory, 105, 168, 169, 225 Rose Gottlieb, fat tests, 35, 39, 41, 43 Salt, analysis of, 638-641 test for butter, 615-618 Samplers, 81 Samples, composite, see composite samples Sampling, accessories, for, 80, 81 butter, 88 Ijuttermilk, 89 cheese, 89 cocoa, 92 cream, 83 evaporated milk, 87 ice cream mix, 87 milk, 82-86 milk powder, malted milk and milk chocolate, 91 sweetened condensed milk, 87 whey, 90 Sandiness, in ice cream, causes and prevention of, 289-298 influence of size of milk sugar crystals on, 290-293 influence of amount of overrun on, 293 influence of composition of milk on, 293 influence of miscellaneous factors, on, 293 influence solubilitv of milk sugar on, 294-298 relation of milk sugar to, 289-298 summary of conclusions on causes of, 296-297 Score cards, development of, 772 for butter. 790-792 for cheese, 794-795, 796, 798 for cream, 788 for culture, 792 for evaporated milk, 802-804 for milk, m-m, 787 for milk powder, 808-809 for stores, handling milk. 783 for sweetened condensed milk. 804-808 for veterinarian, 780 value of, 772 Sediment test for milk and cream, 605 Shakers, for evaporated milk, 757- 758 Sherbet, for use, with Mojonnier Packaging Machine, 287 Skim-milk, fat test for, 11, 16 sampling, 86 score card for, 787 solids test for. 124 specific heat of. 652-653-656 Sodium bicarbonate, use of, in evaporated milk. 740, 747-751. 714 Solids, in dairy products, 120-129 defects in ice cream due to, 289 function of, in ice cream mixes. 281 standards for. 824-826, 829 906 Indkx of Subji:cts variations in, 13, 15 Solids, not fat, defects in ice cream due to, 289 composition ratios of, for ice cream mixes, 273 in milk, 11 specific gravity of, 16 standards for, 824-826, 830 variations in, 13, IS Solubility, of milk sugar, 23, 25, 294, 296 Solutions, standard, preparation of. 596-600 Specific gravity, calculation, in evaporated milk. 176-178 conversion to Twaddell, 865 conversion to Baume, 870-874 determination of. in dairy prod- ucts, 649-652 determinations, 554-560 instruments for determining, 179. 554-564 of alcohol, 44, 884, 886 of ammonia, 44 of butter, 654-656 of butter fat, 654-655 of evaporated milk, 172-181 of ice cream, 275 and 278, 304 of milk, 59, 652, 656 of sweetened condensed milk. 22S-235 of unsweetened condensed milk, 434-437 of whey, 654 solids in milk by formula, 58 standards relating to, 833 Spoilage, detection of, in (.vapor- ated milk, 760-761 Standards, 810-848 citv, 828-848 state, 822-828 state, on bacteria content, of milk. 822 state, on pasteurization. 823 U. S. Department of Agriculture. 810-822 Standardization, definition of, 130 obtaining weights for, 132 order of operations in, 140, 141 use of tables for, 132 successive steps in, 131 Standardization, of milk and cream, 142-161 by Pearson's method, 143-145 by Cross's method, 146-149 by Erf's method, 150, 151 problems, 151-161 Standardization of evaporated milk, order of operations, 166-169 problems for, 192-219 tables, 180-190 Standardization of ice cream mix, 301-432 definition of, 301 methods of compounding, 302-305 problems, 310-432 steps involved in, 301 Standardization of sweetened con- densed milk, 220-271 principles underlying, 162, 220 problems in, 249-271 steps in, 221-222 Standardization problems, problems 1-6, for cream and whole milk, 143-161 problems 7-17, for evaporated milk, 192-219 problems 18-24, for sweetened condensed milk, 249-270 ])roblems 26-36, for ice cream mixes, 316-350 problems 2>7, example 39, proof of accuracy of standardizing tables, 366 problem i7. example 40, proof, of accuracy of standardizing tables, 366 " Starch, in ice cream mix. 286 State Standards, 822-828 Steam, available heat units in, va- rious pressures, 708 condensed into whole milk, in the hot wells, 700 distribution in sterilizer, 738-739 relation of. to fuel production, 703-704 reciuired to condense milk in the vacuum pan, 698-705 re(|uired to forewarm and con- dense, 701-702 saturated, properties of, 874-875 Sterilization, of evaporated milk. 719-755, 758 Sterilizers, for use with Mojonnier Culture Controller, 534 for sterilization of evaporated milk, 720-721 steam distribution in evaporated milk. 7,^^8-739 IXDF.X OF SUBM'XTS 90/ Store, score card for, handling milk, 783 Striking the batch, of evaporated milk, 171-181 of s\\eetcncd condensed milk, 225-233 Sucrate of lime, in milk and cream. 636 Sucrose, (cane sugar), (beet sugar) available heat of combustion, of. 275 crystals, 226 defects in ice cream due to, 298 determination of. 583-591 function of, in ice cream mix. 285 sweetening power of, 285, 286 Sugars, definition of, and standard for, 816-818 Sugar, cane, see sucrose Superheating milk, in the vacuum pan, 710-712 Sweetened condensed milk, capacity and size of standard equipment for manufacture of, 234 composition of. 239 composite samples of. 222 condensing, in the vacuum pan, 716 constants for, 221 definition of, 811 factor of safety in standardizing. 249 Federal standard for, 811 kev to formulas for standardiz- i'ng. 248 methods of testing. 222 ot)taining weights of. 225 operation of vacuum pan when making. 716 order of operations when stand- ardizing, 223 pycnometer cup for, 233 problems in standardizing. 249- 271 relations of specific gravitv in, 226-232 sampling, 87 score card for, 804-808 standardization of, 220-271 solids test for, 125 test for fat in, 108 temperature to heat and hold. 856 types of coolers for. 235-238 Tanks, capacity of cylindrical, 887 evaporated milk holding, 179-180 ice cream holding, 308-310 ice cream batch mixing, 308-310 Temperature, for holding manufacturing and storing dairy products, 855 freezing, 832 inlluence of, on the solubilitj^ of metals in milk, 858 of brine, for freezing ice cream, 457. 458 of mix. 459 of ice cream. 459 of hardening room, 460 of incubation, 514, 524 of sterilization. 721, 722-724, 742 table for conversion from Centi- grade to Fahrenheit and visa versa, 883 Test, acid, for milk and cream. 601 alcohol for milk. 606 bacteriological, 498-521 color. 609 fat, 35-41. 43-61. 93-119 heated milk, 609 microscopical, 515-521 salt, for butter, 615-618 sediment for milk, 605 Tester, Mojonnier Milk, 4. 35, 43-61, 62- 72, 93-129, 169 Mojonnier Overrun Tester, 463- 475 sediment, 605 Thermometers, 6, 65 Reckman, 275 Thickeners, detection of, 633-636 Total solids, by formula. 59 cause of low and high results when making, 128-129 composition ratios of, 273 for butter milk, 124 for evaporated milk, 124 for ice cream, cream, cheese and butter, 126-128 for milk chocolate, malted milk and cocoa, 127 for sweetened condensed milk. 125 908 Index of Subjects for whole milk powder, skim-niilk powder, and buttermilk powder, 128 tests. 56-58 Trier, butter and cheese, 81 U Unsweetened condensed milk, action of, on tin and iron, 862 definition of, 811 fat test for, 108 flow sheet of, manufacture, 851 processing score card for, 801 solids test for, 124 specific gravity of. 434, 436. 437 standardization of. 433-444 temperatures to heat and hold. 856 V Vacuum pan, air leaks in, 713 cleaning, 713, 714 condensing buttermilk in, 718 condensing ice cream mix in. 302, 303, 717. 718 condensing malted milk in, 718 condensing whey in. 718 condensing whole and skim-milk in, 716-717 condition of heating surfaces, 712 description of, 686-689 economic advantage of, 684, 686 entrainment losses in, 715 history of, 684 how to strike the liatch in, 710 how to superheat the batch in, 710, 711, 712 increase of water required due to the decrease in the temperature of the w^ater vapors, 697, 698 location of control devices on, 693, 694 method, Mojonnier, for making ice cream mixes, 302-304 operation of, 705-718 precautions in operation of, 712- 715 purpose and use of, 684-718 rate of evaporation in, 687, 688 relation of the water required in the condenser to the water re- moved from the milk in, 694, 695, 696 sizes and capacities of, 689, 690 sizes of piping for, 692-694 sizes of vacuum pumps for, 692 steam required to condense milk in, 702 striking devices for, 178 striking the evaporated milk batch in, 171-181 striking the sweetened condensed milk batch in. 225-233 water, steam and fuel required to operate, 703, 704 Vacuum oven, vacuum in, for solids test, 122, 123 valves controlling, 103 temperature for solids, 122 Vacuum pump, care of, 70 filling with oil, 104 for jMojonnier Tester, 70 Vacuum pump, wet. 691-692 sizes of. 692 Vanilla extracts, analysis of, 641-645 Ventillation, for laboratory. 2 Veterinarian score card, 780 Viscogen, see sucrate of lime Viscosimeter, Mojonnier-Doolittle, 273, 566-568 Viscosity, determination of, in dairv prod- ucts, 566-568 of evaporated milk. 743-751, Kil- led of ice cream mixes. 273. 277 relation of gelatin to. in ice cream mixes. 282 Vitamines, in milk, 30 in ice cream mix, 281 W Wagons, regulations relating to de- livery, 839 Water, amount of metal required to impart taste to, 857 circulating unit, 70 defects in ice cream due to, 289- 300 filling tank with, 104 in milk, 11. 12. 16 in Mojonnier test. 44. 45 puritA' of. 45 required in the vacuum i)an. 694- 698 supplv. regulations relating to, 833 Water circulating unit, for iNIojonnier Tester, 70 Index of Subjects 909 Weighing, cross, 94 directions for, 73-78. 94-97 evaporated milk, 170 extraction flask, 96 fat dishes. 102 influence of temperature in, 73, 77 pipettes, 94, 95 samples for solids test, 120, 121 Weights, tables for conversion of. 876-882 Weights, care of. 74 directions for recording. 76 for chemical balance. 74. 75 metric, 76 of evaporated milk, methods for obtaining. 170 of ice cream mixes, 274, 277 of various dairy products used in standardizing ice cream mixes, 306 Whey, condensing, in the vacuum pan, 718 fat test for. 106 sampling, 90 specific heat of, 654 temperature to hold, 855 total solids test for. 124 X Xylol, 7 Yogurt, 27 Zinc dust, 7