Class Book Copyright 1^^ CQEXRIGHT DEPOSili THE BOOK OF CHEESE E\\t i^ural Eext=i3ook Series Edited by L. H. BAILEY Carleton : The Small Grains. B. M. Duggar : The Physiology of Plant Production. J. F. Duggar : Southern Field Crops. Gay : Breeds of Live-Stock. Gay : Principles and Practice of Judging Live-Stock. Goff : Principles of Plant Culture. Guthrie : Book of Butter. Harper: Animal Husbandry for Schools. Harris and Stewart: Principles of Agron- omy. Hitchcock : Text-book of Grasses. Jeffery : Text-Book of Land Drainage. Jordan: Feeding of Animals. Revised. Livingston : Field Crop Production. Lyon: Soils and Fertilizers. Lyon, Fippin and Buckman : Soils, their Properties and Management. Mann: Beginnings in Agriculture. Montgomery : The Corn Crops. Morgan : Field Crops for the Cotton-Belt. Mumford: The Breeding of Animals. Piper : Forage Plants and their Culture. Sampson : Effective Farming. ITiom and Fisk : The Book of Cheese. Warren : The Elements of Agriculture. Warren : Farm Management. Wheeler : Manures and Fertilizers. White : Principles of Floriculture. Widtsoe : Principles of Irrigation Prac- THE BOOK OF CHEESE BY CHARLES THOM INVESTIGATOR IN CHEESE, FORMERLY AT CONNECTICUT AGRICULTURAL COLLEGE WALTER W. FISK ASSISTANT PROFESSOR OF DAIRY INDUSTRY (CHEESE-MAKING), NEW YORK STATE COLLEGE OF AGRICULTURE AT CORNELL UNIVERSITY Neto gork THE MACMILLAN COMPANY 1918 All rights reserved sv; ^K COPYBIGHT, 1918, By the MACMILLAN COMPANY. Set up and electrotyped. Published July, 1918. Koriuoot) ^xt9i J. S. Cushing Co. — Berwick & Smith Co. Norwood, Mass., U.S.A. JUL 17 1918 ©Gi.A498759 PREFACE Certain products we associate with the manufactures of the household, so familiar and of such long standing that we do not think of them as requiring investigation or any special support of science. The older ones of us look back on cheese as an ancient home product ; yet the old-fashioned hard strong kind has given place to many named varieties, some of them bearing little resem- blance to the product of the kitchen and the buttery. We have analyzed the processes ; discovered micro- organisms that hinder or help ; perfected devices and machines ; devised tests of many kinds ; studied the chemistry ; developed markets for standardized com- modities. Here is one of the old established farm in- dustries that within a generation has passed from the housewife and the home-made hand press to highly per- fected factory processes employing skilled service and handling milk by the many tons from whole communi- ties of cows. This is an example of the great changes in agricultural practice. Cheese-making is now a piece of applied science; many students in the colleges are studying the subject ; no one would think of undertaking it in the old way : for these reasons this book is written. This book is intended as a guide in the interpretation of the processes of making and handling a series of im- portant varieties of cheese. The kinds here considered are those made commercially in America, or so widely met in the trade that some knowledge of them is neces- VI PREFACE sary. The relation of cheese to milk and to its production and composition has been presented in so far as required for this purpose. The principles and practices under- lying all cheese-making have been brought together into a chapter on curd-making. A chapter on classification then brings together into synoptical form our knowledge of groups of varieties. These groups are then discussed separately. The problems of factory building, factory organization, buying and testing milk, and the proper marketing of cheese, are briefly discussed. Such a discussion should be useful to the student, to the beginner in cheese-making, as a reference book on many varieties in the hands of makers who specialize in single varieties, and to the housekeeper or teacher of domestic science. The material has been brought to- gether from the experience of the writers, supplemented by free use of the literature in several languages. Stand- ard references to this literature are added in the text. No introduction to the subject of cheese should fail to mention the work of J. H. Monrad, who has recently passed away. Mr. Monrad never collected his material into a single publication, but his contributions to cheese- making information, scattered widely in trade literature over a period of thirty years, form an encyclopedia of the subject. Bulletins of the Agricultural Experiment Stations and United States Department of Agriculture have been quoted extensively, with citation of the sources of the material. Personal assistance from Professor W. A. Stocking and other members of the Dairy Department of Cornell University, and C. F. Doane of the United States Department of Agriculture, is gladly acknowledged. Students cannot learn out of books to make cheese. PREFACE Vii They may, however, be aided in understanding the prob- lems from such study. To make cheese successfully they must have intimate personal touch with some person who knows cheese. Sympathetic relations with such a teacher day by day in the cheese-room are essential to suc- cess in making cheese which, at its best, is one of the most attractive of food-products. The Authors. TABLE OF CONTENTS CHAPTER I PAOE9 General Statement on Cheese 1-4 Nature of cheese, 1 ; Cheese-making as an art, 2 ; Cheese-making as a science, 3 ; Problems in cheese- making, 4 ; History, 5. CHAPTER II The Milk in Its Relation to Cheese . . . 5-28 Factors affecting tlie quality, 6 ; Chemical com- position, 7 ; Factors causing variation in composi- tion, 8 ; Milk constituents, 9 ; Water, 10; Fat, 11; Casein, 12 ; Milk-sugar, 13 ; Albumin, 14 ; Ash, 15 ; Enzymes, 16 ; The flavor of feeds eaten by the cow, 17 ; Absorption of odors, 18 ; Effect of condition of the cow, 19; Bacteria in the milk, 20; Croups of bacteria in milk, 21 ; Acid fermentation of milk, 22; Bacterium lactis-acidi group, 2:5 ; Colon-aerogenes group, 24 ; Acid peptonizing group, 25 ; Bacillus bulgaricus group, 26 ; Acid cocci or weak acid- producers, 27 ; Peptonizing organisms, 28 ; Inert types, 29 ; Alkali-producing bacteria, 30 ; Butyric fermenting types, 31 ; Molds and yeasts, 32 ; Bacterial contamination of milk, 33 ; Germicidal effect of milk, 34 ; Sources and control of bacteria in milk, 35 ; The cow, 36 ; Stable air, 37 ; The milker, 38 ; Utensils, 39 ; The factory, 40; The control of l)acteria, 41; Fer- mentation test, 42 ; The sediment test, 43. CHAPTER III Coagulating Materials 29-40 Ferments, 44 ; Nature of rennet, 45 ; Preparation of rennet extract, 46 ; Pepsin, 47 ; Chemistry of Ix X TABLE OF CONTENTS PAGES curdling, 48 ; Use of acid, 49 ; Robertson's theory, 50 ; Rennet curd, 51 ; Hammarsten's theory, 52 ; Duclaux theory, 53 ; Bang's theory, 54 ; Bosworth's theory, 55. CHAPTER IV Lactic Starters 41-54 Acidifying organisms, 56 ; Starter, 57 ; Natural starter, 58; Commercial starter or pure cultures, 59 ; Manufacturer's directions, 60 ; Selecting milk, 61 ; Pasteurization, 62 ; Containers, 63 ; Adding cultures, 64; Cleanliness, 65; "Mother" starter or startoline, 66 ; Examining starter, 67 ; Second day's propagation, 68 ; Preparations of larger amount of starter, 69 ; Amount of mother starter to use, 70 ; Quahties, 71 ; How to carry the mother starter, 72 ; Starter score-cards, 73 ; Use of starter, 74 ; The amount of starter to use, 75 ; Starter lot-card, 76. CHAPTER V Curd-making • 55-80 The composition of the milk, 77 ; Cheese color, 78 ; The acidity factor, 79 ; Acidity of milk when received, 80 ; The acid test, 81 ; Rennet tests, 82 ; Marschall rennet test, 83 ; Comparison of acid and rennet test, 84 ; Control of acid, 85 ; Acidity and rennet action, 86 ; Acidity and expulsion of the whey, 87 ; Acidity in relation to cheese flavor, 88 ; Acidity in relation to body and texture of cheese, 89 ; Acidity in relation to cheese color, 90 ; Control of moisture, 91 ; Relation of moisture to manufacture and quality, 92 ; Relation of moisture to acidity, 93 ; Setting temperature, 94; Strength of coagulating materials, 95 ; Amount of coagulating materials to use, 96 ; Method of adding rennet, 97 ; The curdling period, 98 ; Cutting or breaking the curd, 99 ; Curd knives, 100; Heating or "cooking," 101; Draining, 102 ; Application to cheese, 103. TABLE OF CONTENTS XI CHAPTER VI Classification Basis of classification, 104 ; Processed cheeses, 105 ; Whey cheeses, 106 ; Soft and hard cheeses, 107 ; Relation of moisture to classes, 108 ; Relation of heat to classes, 109. PAGES 81-88 CHAPTER Vn Cheeses with Sour-milk Flavor . . . . Skim series, 110; Cottage cheese. 111; Household practice, 112; Factory practice, 113; Buttermilk cheese, 114; Neufchatol group, 115; Domestic or American Neufchatel cheeses, 116; The factory, 117; Cans, 118; Draining racks, 119; Cloths, 120 Molding machinery, 121 ; Milk for Neufchatel, 122 Starter, 123 ; Renneting or setting, 124 ; Draining 125; Cooling Neufchatel, 126; Pressing, 127 Working and salting Neufchatel, 128 ; Storage, 129 Molding, 130; Skimmed-milk Neufchatel, 131 Baker's cheese, 132 ; Domestic Neufchatel, 133 Partially skim Neufchatel, 134 ; Cream cheese, 135 Neufchatel specialties, 136 ; Gervais, 137 ; European forms occasionally imported, 138. 89-110 CHAPTER VIII Soft Cheeses Ripened by Mold .... Hand cheese and its allies, 139 ; Pennsylvania pot cheese, 140; Appetitost (Appetite cheese), 141; Ripened Neufchatel, French process, 142 ; The Camembert group, 143 ; Camembert cheese, 144 ; Description of Camembert, 145 ; Conditions of making and ripening, 146 ; Outline of making pro- cess, 147 ; Acidity, 148 ; Ripening the cheese, 149 ; Composition, 150; Factory, 151; Economic factors, 152 ; French Brie, 153 ; Coulommiers, 154. 111-133 xii TABLE OF CONTENTS CHAPTER IX PAGES Soft Cheeses Ripened by Bacteria .... 134-148 The Isigny group, 155 ; Raffine, 156 ; Lieder- kranz cheese, 157 ; Limburger cheese, 158 ; The milk, 159 ; Making the cheese, 160 ; Draining and salting, 161 ; Ripening, 162 ; Marketing and quahties of Limburger, 163 ; Yield and composition of Lim- burger, 164 ; Munster cheese, 165. CHAPTER X Semi-hard Cheeses 149-171 The green mold group, 166 ; Roquefort cheese, 167 ; Cow's milk or Faxons Roquefort, 168 ; Outline of making Roquefort, 169 ; Ripening of Roquefort, 170; Gorgonzola, 171; Stilton cheese, 172; Gex, 173 ; Bacterially-ripened series, 174 ; Brick cheese, 175; Making of brick cheese, 176; Ripening brick cheese, 177; Quahties of brick cheese, 178 ; Composi- tion and yield, 179 ; Port du Salut cheese, 180. CHAPTER XI The Hard Cheeses 172-183 The Danish group, 181 ; The Dutch group, 182 ; Edam cheese, 183 ; Method of manufacture, 184 ; Salting and curing Edam, 185; Equipment for making Edam cheese, 186; Quahties and yield of Edam cheese, 187; Gouda cheese, 188; Method of manufacture, 189; Equipment for Gouda cheese, 190; Composition and yield, 191. CHAPTER XII Cheddar Cheese-making 184-221 The lot-card, 192 ; The milk, 193 ; Ripening the milk, 194; Setting or coagulating, 195; Cutting, 196 ; Heating or "cooking" the curd, 197 ; Removing the whey, 198 ; Hot-iron test, 199 ; Firmness of the curd, 200 ; Gathering the curd together, 201 ; TABLE OF CONTENTS Xlll Matting or cheddaring, 202 ; Milling the curd, 203 ; Salting, 204 ; Hooping the curd, 205 ; Pressing the curd, 206 ; Dressing the cheese, 207 ; HandUng over- ripe and gassy milk, 208 ; Qualities of Cheddar cheese, 209. CHAPTER XIII Composition and Yield op Cheddar Cheese Composition of milk, whey and cheese, 210 ; Relations of fat to casein in normal milk, 211; Influence of fat in milk on yield of cheese, 212 ; Fat loss in cheese-making, 213 ; Effect of bacterial- content of milk on yield of cheese, 214 ; Factors affecting the moisture-content of Cheddar, 215 ; Variations of the Cheddar process, 216 ; Cheddar- type cheese from pasteurized milk, 217 ; Club cheese, 218; The stirred-curd or granular process, 219; Cahfornia Jack cheese, 220 ; The washed-curd process, 221 ; English dairy cheese, 222 ; Pineapple cheese, 223 ; Leyden, 224 ; Cheddar cheese with pimientos, 225 ; Sage cheese, 226 ; Skimmed-milk cheese, 227 ; Full skimmed-milk Cheddar cheese, 22.8 ; Half skimmed-milk Cheddar cheese, 229 ; Yield and qualities of skimmed-milk Cheddar cheese, 230. 222-246 CHAPTER XIV Cheddar Cheese Ripening Fat, 231; Milk-sugar, 232; The salts, 233; Gases, 234 ; Casein or proteins, 235 ; Causes of ripening changes, 236 ; Action of the rennet extract, 237 ; The action of the bacteria, 238 ; Conditions affecting the rate of cheese ripening, 239 ; The length of time, 240 ; The temperature of the curing- room, 241 ; Moisture-content of the cheese, 242 ; The size of the cheese, 243 ; The amount of salt used, 244 ; The amount of rennet extract, 245 ; The influence of acid, 246 ; Care of the cheese in the curing-room. 247-275 XIV TABLE OF CONTENTS PAGES 247; Evaporation of moisture from the cheese during ripening, 248 ; Paraffining, 249 ; Shipping, 250. Defects in Cheddar cheese: Defects in flavor, 251 ; Feedy fiavors, 252 ; Acid flavors, 253 ; Sweet or fruity flavors, 254; Defects in body and texture, 255 ; Loose or open texture, 256 ; Dry body, 257 ; Gassy textured cheese, 258 ; Acidy, pasty or soft body and texture, 259 ; Defects in color, 260 ; Defects in finish, 261. Cheddar cheese judging: Secur- ing the sample, 262 ; How to determine quality, 263 ; Causes of variations in score, 264 ; The score- card, 265. CHAPTER XV The Swiss and Italian Groups 276-292 Swiss cheese: The Swiss factory, 266; The milk, 267 ; Rennet extract, 268 ; Starter, 269 ; The making process, 270 ; Curing Swiss, 271 ; Block Swiss, 272 ; .. Shipment, 273 ; Qualities of Swiss cheese, 274 ; Composition and yield, 275 ; The Italian group : Parmesan, 276 ; Regianito, 277. CHAPTER XVI Miscellaneous Varieties and By-products . 293-296 Caciocavallo, 278 ; Sap sago, 279 ; Albumin cheese, 280 ; Mysost, Norwegian whey cheese, 281 ; Whey butter, 282. CHAPTER XVII Cheese Factory Construction, Equipment, Organi- zation . 297-310 Locating the site, 283 ; The building, 284 ; Heat- ing plant, 285 ; Curing-rooms, 286 ; Light, 287 ; Ventilation, 288 ; Boiler-room, 289 ; whey tanks, 290; Store-room, 291; The floors, 292; Arrange- ment of machinery and rooms, 293 ; Arrangements for cleanliness, 294 ; Equipment and supplies list, 295 ; Factory organization, 296. TABLE OF CONTENTS XV CHAPTER XVIII PAGES History and Development of the Cheese Industry IN America 311-326 The factory system, 297 ; Introduction of factory system in Canada, 298 ; Introduction of cheddaring, 299 ; Introduction of Swiss and Limburger, 300 ; Number and distribution of cheese factories, 301 ; Total production of cheese in the United States, 302 ; Rank of the leading cheese-producing states, 303 ; Exportation and importation of cheese by the United States, 304 ; Average yearly price of cheese, 305 ; Canadian cheese statistics, 306 ; Introduction of cheese-making into new regions, 307. CHAPTER XIX Testing 327-342 • The fat test, 308 ; SampUng the milk, 309 ; Adding the acid, 310; Centrifuging, 311 ; Reading the test, 312 ; testing whey for fat, 313 ; testing cheese for fat, 314 ; Reading the test, 315 ; The Hart casein test, 316 ; Sohds in the milk, 317 ; the lactometer, 318; Calculating the solids not fat in the milk, 319; Testing cheese for moisture, 320. CHAPTER XX Marketing 343-361 Buying milk, 321 ; Cheese yield basis of buying milk, 322 ; Fat basis for payment of milk, 323 ; Weight basis or pooling method for payment of milk, 324 ; Fat-plus-two method for payment of milk, 325 ; Comparison of methods, 326 ; Laws governing the production and sale of milk, 327 ; Marketing of cheese, 328 ; Mercantile exchanges, 329 ; Marketing perishable varieties, 330 ; Dis- tribution of price, 331 ; Standards, 332 ; Laws relating to cheese marketing, 333. XVI TABLE OF CONTENTS CHAPTER XXI PAGES Cheese in the Household . . . ". . 362-381 Food value of cheese, 334 ; Digestibility of cheese, 335 ; Cheese flavor, 336 ; Relation to health, 337 ; Cheese poisoning, 338 ; Proper place in the diet, 339 ; Care of cheese, 340 ; Food value and price, 341 ; Methods and recipes for using cheese, 342. THE BOOK OF CHEESE THE BOOK OF CHEESE CHAPTER I GENERAL STATEMENT ON CHEESE Cheese is a solid or semi-solid protein food product manufactured from milk. Its solidity depends on the curdling or coagulation of part or all of the protein and the expulsion of the watery part or whey. The coag- ulum or curd so formed incloses part of the milk-serum (technically whey) or watery portion of the milk, part of the salts, part or all of the fat and an aliquot part of the milk-sugar. The loss in manufacture includes a small fraction of the protein and fat, the larger propor- tion of the water, salts and milk-sugar. 1. Nature of cheese. — Milk of itself is an exceedingly perishable product. Cheese preserves the most important nutrient parts of the milk in condition for consumption over a much longer period. The duration of this period and the ripening and other changes taking place depend very closely on the composition of the freshly made cheese. There is an intimate relation between the water, fat, protein and salt-content of the newly made cheese and the ripening processes which produce the particular flavors of the product when it is ready for the consumer. This relation is essentially biological. A cheese contain- B 1 2 THE BOOK OF CHEESE ing 60 to 75 per cent of water, as in " cottage cheese " (the sour-milk cheese so widely made in the homes), must be eaten or lost in a very few days. Spoilage is very rapid. In contrast to this, the Italian Parmesan, with 30 to 32 per cent of water, requires two to three years for proper ripening. The cheeses made from soured skim-milk probably represent the most ancient forms of cheese-making. Their origin is lost in antiquity. The makers of Roque- fort cheese cite passages from Pliny which they think refer to an early form of that product. It is certain that cheese in some form has been familiar to man throughout historic times. The technical literature of cheese-making is, however, essentially recent. The older literature may be cited to follow the historical changes in details of practice. 2. Cheese-making as an art has been developed to high stages of perfection in widely separate localities. The best kno^\^l varieties of cheese bear the geographical names of the places of their origin. The practices of making and handling such cheeses have been developed in intimate relation to climate, local conditions and the habits of the people. So close has been this adjustment in some cases, that the removal of expert makers of such cheeses to new regions has resulted in total failure to transplant the industry. 3. Cheese-making as a science has been a compara- tively recent development. It has been partly a nat- ural outgrowth of the desire of emigrant peoples to carry with them the arts of their ancestral home, partly the desire to manufacture at home the good things met in foreign travel. Its development has been largely coincident with the development of the agricultural school GENERAL STATEMENT ON CHEESE 3 and the science of dairy biology. Even now we have but a Hmited knowledge of a few of the 500 or more varieties of cheese named in the literature. It is desirable to bring together the knowledge of underlying principles as far as they are knoA\Ti. No technical description of a cheese-handling process can replace experience. Descriptions of appearances and tex- tures of curd in terms definite enough to be understood by beginners have been found to be impossible. It is possible, however, to lay down principles and essentials of practice which are common to the industry and form the founda- tion for intelligent work. Cheese-making will be a science only as we depart from the mere repetition of a routine or rule-of-thumb practice and understand the underlying principles. 4. Problems in cheese-making. — Any understanding of these problems calls for a working knowledge of the very complex series of factors involved. These include the chemical composition of the milk, the nature of rennet and character of its action under the conditions met in cheese-making, the nature of the micro-organisms in milk, and the methods of controlling them, their relation to acidity and to the ripening of the cheese. To these scientific demands must be added acquaintance with the technique of the whole milk industry, from its production and handling on the farm through the multi- plicity of details of factory installation and organization, to those intangible factors concerned with the texture, body, odor and taste of the varied products made from it. Some of these factors can be adequately described ; others have thus far been handed on from worker to worker but have baffled every effort at standardization or definition. 4 THE BOOK OF CHEESE 5. History. — The recorded history of the common varieties of cheese is only fragmentary. Practices at one time merely local in origin followed the lines of emigration. Records of processes of manufacture were not kept. The continuance of a particular practice depended on the skill and memory of the emigrant, who called his cheese after the place of origin. Other names of the same kind were applied by the makers for selling purposes. The wddely known names were thus almost all originally geographical. Some of them, such as Gorgonzola, are used for cheeses not now made at the places whose names they bear. Naturally, this method of development has produced national groups of cheeses which have many common characteristics but differ in detail. The English cheeses form a typical group of this kind. Emigration to America carried English practices across the Atlantic. The story of cheese-making in America has been so closely linked with the development of the American Cheddar process that the historical aspects of the industry in this country are considered under that head in Chapter VIII. CHAPTER II THE MILK IN ITS RELATION TO CHEESE The opaque whitish Hquid, secreted by the mam- mary glands of female mammals for the nourishment of their young, is known as milk. The milk of the cow is the kind commonly used for cheese-making in America. 6. Factors affecting the quality. — The process of cheese-making begins with dra^^■ing the milk from the udder. The care and treatment the milk receives, while being drawn, and its subsequent handling, have a decided influence on its qualities. The process of cheese-making is varied according to the qualities of the milk. There are five factors that influence the quality of the milk for cheese-making : (1) its chemical composition; (2) the flavor of feed eaten by the cow ; (3) the absorption of flavors and odors from the atmosphere ; (4) the health of the cow ; (5) the bacteria present. The first factor is dependent on the breed and individuality of the cow. The other four factors are almost entirely within the control of man. Of these factors, number five is of the most importance, and is the one most frequently neg- lected. 7. Chemical composition. — The high, low and average composition of milk is approximately as follows : 5 THE BOOK OF CHEESE TABLE I Composition of Milk Water Per Cent Fat Per Cent Casein Per Cent Sugar Per Cent Albumin Per Cent Ash Per Cent High . . . Low .... Average . . 88.90 85.05 87.47 5.50 3.00 3.80 3.00 2.10 2.50 5.00 4.60 4.80 .72 .70 .71 .73 .70 .72 8. Factors causing variation in composition. — The composition of cow's milk varies according to several factors. The composition of the milk of different breeds differs to such a degree that whole series of factories are found with lower or higher figures than these averages on account of dominant presence of particular kinds of cattle. The following table shows the usual effect of breed on fat and total solids of milk : TABLE II The Usual Effect of Breed of Cows on Fat and Total Solids of Milk Breed of Cows Jersey .... Guernsey . Shorthorn Ayrshire . Holstein-Friesian 14.74 14.70 13.41 12.72 11.89 THE MILK IN ITS RELATION TO CHEESE 7 The figures^ in Tables I and II are compiled and aver- aged from a large number of analyses made at different agricultural experiment stations. This variation not only affects the fat, but all con- stituents of the milk. While there is a difference in the composition of the milk from cows of different breeds, there is almost as wide variation in the composition of the milk from single cows ^ of the same breed. With the same cow the stage of lactation causes a wide varia- tion in the composition of the milk.^ As the period of lactation advances, the milk increases in percentage of fat and other solids. 9. Milk constituents. — From the standpoint of the cheese-maker, the significant constituents of milk are iQnt. Exp. Sta. Rept. 1890, pages 237-241. Maine Exp. Sta. Rept. 1890, part II, pages 52-57. Conn. (Storrs) Exp. Sta. Rept. 1886, pages 119-130. Vt. Exp. Sta. Rept. 1890, pages 97-100. Vt. E.xp. Sta. Rept. 1891, pages 61-74. N. Y. Exp. Sta. Rept. 1892, pages 299-392. N. Y. Exp. Sta. Rept. 1893, pages 39-162. Wis. Exp. Sta. Rept. 1890, pages 115-119. Conn. (Storrs) Exp. Sta. Rept. 1907, pages 152-156. N. Y. Exp. Sta. Rept. 1891, pages 139-142. N. Y. Exp. Sta. Rept. 1894, pages 31-86, 118-121. N. J. Exp. Sta. Rept. 1895, pages 136-137. Eekles, C. H., and R. H. Shaw. The influence of breed and individuality on the composition and properties of milk. Bur. An. Ind. Bui. 156, 1913. Eekles, C. H., and R. H. Shaw, Variations in the composition and properties of milk from the individual cow, U. S. Dept. Agr. Bur. An. Ind. Bui. 157, 1913. 2 Morrow, G. A., and A. G. Manns, Analyses of milk from different cows, 111. Exp. Sta. Bui. 9, 1890. 3 Eekles, C. H., and R. H. Shaw, The influence of the stage of lactation on the composition and properties of milk, U. S. Dept. Agr. Bur. An. Ind. Bui. 155, 1913. N. Y. Exp. Sta. Rept. 1892, pages 138-140. 8 THE BOOK OF CHEESE water, fat, casein, milk-sugar, all)iiiiiin, ash and enzymes. These will be discussed separately. 10. Water. — The retention of the solids and the elim- ination of the water are among the chief considerations in cheese-making. Water forms 84 to 89 per cent of milk. Cheese-making calls for the reduction of this percentage to that typical of the particular variety of cheese desired with the least possible loss of milk solids. This final percentage ^■aries from 30 to 70 per cent with the variety of cheese. The water has two uses in the cheese : (1) It imparts smoothness and mellowness to the body of the cheese; (2) it furnishes suital)le conditions for the action of the ripening agents. To some extent the water may sui^plement or even replace fat in its effect on the texture of the cheese. If the cheese is pro])erly made, the water present is in such combination as to give no suggestion of a wet or " lcak>' " product. 11. Fat. — 1^'at is present in the milk in the form of suspended small transparent globules (as an emulsion). These globides \ary in size with the breed and individ- uality of the cow and in color from a very light yellow to a deep yellow shade as sought in butter. Milk with small fat globules is jireferred for cheese-making, because these are not so easily lost in the process. ]\Iilk-fat is made up of several different compounds called glycerids/ which are formed by the union of an organic acid with glycerine as a base. Fat is important in cheese-making for two reasons: (1) Its influence on the yield of cheese; (2) its effect IN. Y. Exp. Sta. Ropt. 1891, pages 143-162, 316-318. Wis. Exp. Sta. Rept. 1890, pagos 238-247. Van Slyke, L. L., Conditions affecting the proportions of fat and protein in cow's milk. Jour. Am. Chcm. Soc, 30 (1908), no. 7, pages 1166-1186. THE MILK IN ITS RELATION TO CHEESE 9 on the quality of the cheese. Many of the details of cheese-making processes have been developed to prevent the loss of fat in manufacture. The yield of cheese is almost directly in proportion to the amount of fat in the milk; nevertheless, because the solids not fat do not in- crease exactly in proportion to the fat, the cheese yield is not exactly in proportion to the fat. The fat, however, is a fjjood index of the cheese-producing power of the milk. 12. Casein. — Cheese-making is possible because of the peculiar properties of casein. This is the fundamental substance of cheese-making because it has the capacity to coagulate or curdle under the action of acid and rennet enzymes. Casein is an extremely complex organic com- pound.^ Authorities disagree regarding its exact com- position, but it contains varying amounts of carbon, oxygen, nitrogen, hydrogen, i)hosphorus and sulfur, and it usually is combined with some form of lime or cal- cium phosphate. It belongs to the general class of nitrogen-containing compounds called proteins. It is present in milk in the form of extremely minute gelat- inous particles in suspension. Casein is insoluble in water and dilute acids. The acids, when added, cause a heavy, white, more or less flocculent precipitate. Rennet (Chapter III) causes the casein to coagulate (curdle), forming a jelly-like mass called curd, which is the basis of manufacture in most types of cheese. In 1 Van Slyke, L. L., and A. W. Bosworth, Composition and properties of some casein and paracasein compounds and their relations to cheese, N. Y. Exp. Sta. Tech. Bui. 26, 1912. Forbes, E. B., and M. H. Keith, A review of the litera- ture of phosphorus compounds in animal metabolism, Ohio Exp. Sta. Tech. Bui. .5, pages 32-36, 42-45. Van Slyke, L. L., and A. W. Bosworth, Condition of casein and salts in milk, N. Y. Exp. Sta. Tech. Bui. 39. 10 THE BOOK OF CHEESE the formation of this coagulum (curd), the fat is imprisoned and held. The casein compounds in the curd hold the moisture and give firmness and solidity of body to the cheese. Casein contains the protein materials in which important ripening changes take place. These changes render the casein more soluble, and are thought to be the source of certain characteristic cheese flavors. 13. Milk-sugar. — Milk-sugar (lactose) is present in solution in the watery part of the milk. It forms on the average about 5 per cent of cow's milk. Since it is in solution, cheese retains the aliquot part of the total represented by the water-content of the cheese, plus any part of the sugar which has entered into combination with the milk solids during the souring process. The larger part of the lactose passes off with the whey. Lactose^ is attacked by the lactic-acid bacteria and by them is changed to lactic acid. Cheeses in which this souring process goes on quickly, soon contain a large enough percentage of acid to check the rotting of the cheese by decay organisms. Without this souring, most varieties of cheese will begin to spoil quickly. For each variety there is a proper balance between the souring, which interrupts the growth of many kinds of putrefactive bacteria, and the development of the forms which are essential to proper ripening. 14. Albumin. — This is a form of protein which is in solution in the milk. Albumin forms about 0.7 per cent of cow's milk. It is not coagulated by rennet. Most rennet cheeses, therefore, retain only that portion of the total albumin held in solution in the water retained, as in the case of milk-sugar. Albumin is coagulated by heat, forming a film or membrane upon the surface. There 1 Wis. Exp. Sta. Rept. 1901, pages 162-166. THE MILK IN ITS RELATION TO CHEESE 11 are certain kinds of cheese, such as Ricotte, made by the recovery of albumin by heating. 15. Ash. — The ash or mineral constituents make up about 0.7 per cent of cow's milk. This total includes very small amounts of a great many substances. The exact form of some of the substances is still unknown. Of these salts, the calcium or lime and phosphorus salts are most important in cheese-making. They are par- tially or completely precipitated by pasteurization. After such precipitation rennet fails to act ^ or acts very slowl}^ ; hence pasteurized milk cannot be used for making rennet cheese unless the lost salts are replaced, or the condition of the casein is changed by the addition of some substance, before curdling is attempted. 16. Enzymes. — Milk also contains enzymes. These are chemical ferments secreted by the udder. They have the power to produce changes in organic compounds with- out themselves undergoing any change. Minute amounts of several enzymes are found in milk as follows : Diastase, galactase, lipase, catalase, peroxidase and reductase. Just what part they play in cheese-making is not definitely known. 17. The flavor of feeds eaten by the cow, — Unde- sirable flavors in the milk are due many times to the use of feed with very pronounced flavors. The most common of these feeds are onions, garlic, turnips, cabbage, de- cayed ensilage, various weeds and the like. These im- desirable flavors reach the milk because the substances are volatile and are able to pass through the tissues of the animal. While feed containing these flavors is "being digested, these volatile substances are not only present ^ Sammis, J. L., and A. T. Bruhn, The manufacture of cheese from pasteurized milk, Wis. Exp. Sta. Research Bui. 27, 1912. 12 THE BOOK OF CHEESE in the milk, but in all the tissues of the animal. By the time the process of digestion is completed, the volatile flavors have largely passed away. Therefore, if the times of milking and feeding are properly regulated, a dairy-man may feed considerable quantities of strong-flavored prod- ucts, such as turnip, cabbage and others, without any appreciable effect on the flavor of the milk. To ac- complish this successfully, the cows should be fed im- mediately before or immediately after milking, preferably after milking. This allows time for the digestive process to take place and for the volatile substances to disappear. If, however, milking is performed three or four hours after feeding, these volatile substances are present in the milk and flavor it.^ In the case of those plants which grow wild in the pasture, and to which the cows have continued access, it is more difficult to prevent bad flavor in the milk. The cows may be allowed to graze for a short time only, and that immediately after milking, without affecting the flavor of the milk. This will make it necessary to supplement the pasture with dry feed, or to have another pasture where these undesirable plants do not grow. Undesirable flavors are usually noticeable in the milk when the cows are turned out to pasture for the first time in the spring; and when they are pastured on rank fall feed, such as second growth clover. 18. Absorption of odors. — Milk, especially when warm, possesses a remarkable ability to absorb and retain odors from the surrounding atmosphere. ^ For 1 Baer, U. S., and W. L. Carlyle, Quality of cheese as affected by food. Wis. Exp. Sta. Bui. lis, 1904. 2 King, F. H., and E. H. Farrington, Milk odor as affected by silage, Wis. Exp. Sta. Bui. 59, 1897. THE MILK IN ITS RELATION TO CHEESE 13 this reason, the milk should be handled only in places free from such odor. Some of the common sources of these undesirable odors are bad-smelling stables, strong- smelling feeds in the stable, dirty cows, aerating milk near hog-pens, barn-yards and swill barrels. The only way to prevent these undesirable flavors and odors is not to expose the milk to them. The safest policy is to remove the source of the odor. 19. Effect of condition of the cow. — Any factor which affects the cow is reflected in the composition and physi- ological character of the milk. (1) Colostrum. Milk secreted just before or just after parturition is different in physical properties and chemical composition from that secreted at any other time during the lactation period. This milk is known as colostrum. It is considered unfit for human food, either as milk or in products manu- factured from the milk. Most states ^ consider colostrum adulterated milk, and prohibit the sale of the product for fifteen days preceding and for five days after par- turition. (2) Disease. When disease is detected in the cow, the milk should at once be discarded as human food. Some diseases are common both to the cow and to man, such as tuberculosis, foot-and-mouth disease. If such diseases are present in the cow, the milk may act as a carrier to man. Digestive disorders of any sort in the cow are frequently accompanied by undesirable flavors in the milk. These are not thought to be due to the feed, but to the abnormal condition of the cow. When the normal condition is restored, these undesirable flavors disappear. 1 N. Y. Agricultural Law, 1913, section 30. Mich. Agricultural Law, 1915, section 77. Wis. Agricultural Law, 1913, section 4601. 14 THE BOOK OF CHEESE 20. Bacteria in the milk. — Bacteria are microscopic unicellular plants, without chlorophyll. Besides bacteria, there are other forms of the lower orders of plants found in milk, such as yeasts and molds. While the bacteria are normally the more important, frequently yeasts and molds produce significant changes in milk and other dairy products. Bacteria are very widely distributed throughout nature. They are so small that they may easily float in the air or on particles of dust. Many groups of bacteria are so resistant to adverse conditions of growth that they may be present in a dormant or spore stage, and, therefore, not be easily recognized ; when suitable environments for growth are again produced, development begins at once. They are found in all surface water, in the earth and upon all organic matter. There are a great many different groups of bacteria ; some are beneficial, and some are harmful. As they are so small, it is difficult to differentiate between the bene- ficial and harmful kinds, except by the results produced, or by a careful study in an especially equipped laboratory. The bacteria multiply very rapidly. This is brought about by fission ; that is, the cell-walls are drawn in at one place around the cell, and when the walls unite at the center, the cell is divided. There are then two bacteria. In some cases, division takes place in twenty to thirty minutes. Like other plants, they are very sensitive to food supply, to temperature and to moisture, as con- ditions of growth. Inasmuch as the bacteria are plant cells, they must absorb their food from materials in solution. They may live on solid substances, but the food elements must be rendered soluble before they can be used. Most bacteria prefer a neutral or slightly acid medium for growth, rather than an alkaline reaction. THE MILK IN ITS RELATION TO CHEESE 15 Ordinary milk makes a very favorable medium for the growth of bacteria, because it is an adequate and easily available food supply. In milk, certain groups of bacteria are commonly present, but many others which happen to get into it live and multiply rapidly. A favorable temperature is very necessary for such organisms to multiply. There is a range of temperature, more or less wide, at which each group of bacteria grows and multiplies with the greatest rapidity. This range varies with the different groups, but most of them find temperatures between 75° F. and 95° F. the most favorable for growth. Ex- cessive heat kills the bacteria. Low temperatures stop growth, but kill few if any bacteria. Temperatures of 50° F. and lower retard the growth of most forms of bacteria found commonly in milk. Many forms will slowly develop, however, below 50° and some growth will occur down to the freezing point. INIilk held at 50° F. or lower will remain in good condition long enough to be handled without injury to quality until received in the cheese factory. In the place of seeds, some groups of bacteria form spores. The spores are exceedingly resistant to unfavorable conditions of growth, such as heat, cold, drying, food supply and even chemical agents. This property makes it difficult to destroy such bacteria. 21. Groups of bacteria in milk. — Milk when first drawn usually shows an amphoteric reaction; that is, it will give the acid and alkaline reactions with litmus paper. Under normal conditions, milk soon begins to undergo changes, due to the bacteria. Changes pro- duced in this way are called " fermentations " ; the agents causing them, " ferments." Normally the acid 16 THE BOOK OF CHEESE fermentation takes place first, and later other fermenta- tions or changes begin, which, after a time, so decom- pose the milk that it will not be suitable for cheese- making or human consumption. The following grouping of the organisms in milk is based on their effects on the milk itself ^ : I. Acid-producing types. II. Peptonizing types. III. Inert types. IV. Alkali-producing types. V. Butyric fermenting types. Each type of bacteria produces more or less specific changes in the milk. As a general rule, the predominance of one of these types is an aid in the interpretation of the quality of the product at the time of analysis, such as the age, the temperature at which it has been held, the conditions under which it was produced and, in some cases, the general source of the contamination. The reaction due to certain bacteria is utilized in the manu- facture and handling of dairy products ; other groups have deleterious effects. (See Fig. 2.) 1 Conn. (Storrs) Exp. Sta. Kept. 1899, pages 13-68. Conn. (Storrs) Exp. Sta. Rept. 190.3, pages 33-98. Conn. (Storrs) Exp. Sta. Rept. 1904, pages 27-88. Esten, W. M., and C. J. Mason, Sources of bacteria in milk. Conn. (Storrs) Exp. Sta. Bui. 51, 1908. Rogers, L. A., and B. J. Davis, Methods of classifying the lactic acid bacteria, U. S. Dept. Agr. Bur. An. Ind. Bui. 154, 1912. Bergey, D. H., The colon-aerogenes group of bacteria. Jour. Med. Research, Boston, Vol. XIX, pages 175-200, 1908. Conn, H. W., Classification of dairy bacteria, Conn. (Storrs) Exp. Sta. Rept. 1906. Rogers, L. A., Bacteria in milk, U. S. Dept. Agr., Farmers' Bui. 490, 1912. THE MILK IN ITS RELATION TO CHEESE 17 22. Acid fermentation of milk. — By far the most common and important fermentation taking place in milk is due to the action of the lactic acid-forming bacteria on the milk-sugar or lactose. The bacteria that bring about this fermentation may be divided into several groups on the basis of their morphology, proteolytic activity, gas production, temperature adaptation and Fig. 2. — Effect of different fermentations of milk: U, Curd pitted with gas holes ; G and 0, gassy curds which float ; K, smooth, solid desirable curd. production of substances other than lactic acid. The larger number of organisms producing lactic acid in milk also produce other organic acids in greater or less abundance. Inasmuch as lactic acid is the principal sub- stance produced, they are called lactic acid organisms. This group contains different kinds of organisms which may be subdivided into small groups as follows : (a) Bacterium lactis-acidi group. (b) Bacterium colon-aerogenes group. 18 THE BOOK OF CHEESE (c) Acid peptonizing group. {d) Bacillus bulgaricus group. (e) Acid cocci or weak acid-producing group. 23. Bacterium lactis-acidi group. — There are many strains or varieties in this group which are closely related in their activities. They are universally present in milk and are commonly the greatest causal agent in its souring. They are widely distributed in nature. At a temperature of 65° F. to 95° F., these bacteria grow and multiply very rapidly; at 70° F. (approximately 20° C.) these forms usually outgrow all others. The total amount of acid produced in milk by these organisms varies from 0.6 of one per cent to 1 per cent acid calculated as pure lactic acid. These forms coagulate milk to a smooth curd of uniform consistency. In addition to the lactic acid, there are produced traces of acetic, succinic, formic and proprionic acids, traces of certain alcohols, alde- hydes and esters. Substances other than lactic acid are not produced by organisms of this group to such an extent as to impart undesirable flavors to the milk. The action of this group on the milk proteins is very slight. They produce no visible sign of peptoniza- tion. The B. lactis-acidi group of organisms are essential to the production of the initial acidity necessary in most types of cheese. The practical culture and utilization of them for this purpose under factory conditions are discussed in Chapter IV, entitled " Lactic Starters." 24. Colon-aerogenes group. — This group takes its name from a typical species, Bacterium coli communis, which is a normal inhabitant of the intestines of man and animals, and from Bacterium coli aerogcues, which is similar in many respects to B. coli communis. The THE MILK IN ITS RELATION TO CHEESE 19 initial presence of these bacteria in milk is indicative of fecal contamination or unclean conditions of production. These organisms, however, grow and develop in milk very rapidly at high temperatures of handling. The total acidity produced by these forms is less than that by the Bacterium lactis-acidi group. Of the acid produced, less than 30 per cent is lactic acid ; the other acids are formic, acetic, proprionic and succinic. The large per- centage of these acids, with comparatively large amounts of certain alcohols, aldehydes and esters, invariably im- part undesirable flavors and odors to the milk. Mem- bers of this group uniformly ferment the lactose with the production of the gases, carbon dioxide and hydrogen. The milk is coagulated into a lumpy curd, containing gas pockets. 25. Acid peptonizing group. — These are often as- sociated with colon organisms. The group includes those bacteria which coagulate milk with an acid curd and subsequently partly digest it. They grow and mul- tiply rapidly at a temperature between 65° and 98° F. They impart undesirable flavors and odors to the milk, which appear to be due to the formation of acids other than lactic acid, and to action on the milk proteins. 26. Bacillus bulgaricus group. — These organisms grow best at a temperature of 105° to 115° F. They will de- velop at lower temperatures, but not so rapidly. They survive heating to 135° F. without loss of vigor, as occurs in Swiss cheese-making. They produce from 1 to 4 per cent of acid in milk, which is practically all lactic acid. They do not produce gas. They impart no undesirable flavors to the milk. 27. Acid cocci or weak acid-producers. — This group of organisms is not very well defined. It consists mostly 20 THE BOOK OF CHEESE of coccus forms, commonly found in the air and in the udder. Their presence in the milk may indicate direct udder contamination. These are regarded as of little importance, unless in very large number, and they have been only partially studied. They produce little or no lactic acid, and small amounts of iacetic, proprionic, butyric and cai)roic acids. These forms rarely create enough acid to coagulate milk. 28. Peptonizing organisms. — This group includes all bacteria which have a peptonizing eft'ect on the milk. It includes the acid peptonizing organisms, although they are of primary importance in the acid type of bac- teria, because the acid-producing power is greater than the peptonizing power. Some of the specific organisms in this class are Bacillus subtilis, Bacterium prodigiosus and Bartrriion liqurfncicns. These are commonly found in soil water and in fecal material. The presence of these organisms denotes contamination from such sources. 29. Inert types. — As the name indicates, these are organisms not known to have an appreciable efi'ect on milk. The ordinary tests fail to connect them with imi)()rtant })rocesses ; hence they appear to feed upon, but not to affect the milk in any serious way. ]\Iilk ordinarily contains more or less of these organisms, but no i)articular significance is attached to their presence. 30. Alkali-producing bacteria. — This group of organ- isms has only recently been studied in relation to its action on milk. Investigators still disagree as to the usual ])ercentage in the normal milk flora. Their pres- ence in milk has been considered to be relatively un- important. 31. Butyric fermenting types. — Organisms causing butyric fermentation may be present in the milk, but THE MILK IN ITS RELATION TO CHEESE 21 seldom become acti^'e, because they are commonly an- aerobic and so will not develop in milk kept under ordinary conditions, and the rapid growth of the lactic acid-forming bacteria prevents their growth. These organisms act on the milk-fat, decomposing it. Butyric acid fermenta- tions are more common in old butter and cheese. In these, the fermentation causes a rancid flavor. 32. Molds and yeasts. — The cattle feed and the air of the barn always contain considerable numbers of yeasts and mold spores. Yeasts have been foiuid by Hastings ^ to cause an objectiona})le fermentation in Wisconsin cheese. No further study of this group as factors in cheese-handling has been reported. Mold spores, es- pecially those of the blue or green molds (Penicillum sp.) and the black molds (Mucors), are always abundant in milk. These spores are carried into all cheeses made from unpasteurized milk, in numbers sufficient to cover the cheeses with mold if they are permitted to grow. Pasteurization '^ kills most of them. The border-line series commonly referred to as the streptothrix-acti- nomyces group are also very abundant in all forage and are carried in large numbers into all milk and its products. 33. Bacterial contamination of milk. — When drawn from the cow, milk is seldom if ever sterile. Organisms usually work their way from the tip of the teat into the udder and multi])ly there. The fore milk usuall}' con- tains more organisms than does that drawn later. Most of the bacterial contamination of the milk is due to the handling after it is drawn from the cow. ^ Hastings, Vj. G., Distribution of lactose-fcrmoiiting yeasts in dairy products, Wis. Exp. Sta. Rept. 23, pages 107-115. 2 Thom, C, and S. H. Ayers, Effect of pasteurization upon mold spores, Jour. Agr. Research 6 (1916), no. 4, pages 153-156. 22 THE BOOK OF CHEESE 34. Germicidal effect of milk. — Authorities agree that when a bacterial examination of the milk is made, hour by hour, beginning as soon as it is drawn from the cow, there is no increase in the number of organisms for a period of several hours at first, but an actual reduction not infrequently takes place. This is called the " germi- cidal " ^ property of milk. The lower the temperature of the milk, the longer and less pronounced is the germi- cidal action ; the higher the temperature, the shorter and more pronounced is tliis action. This is explained as either: (1) a period of selection within which types of bacteria entering by accident and unada{)ted for growth die oft' ; or (2) an actual weak anti- septic power in the milk-serum itself ; or (3) the forming of clusters by the bacteria and so reducing the count. In working on a small scale or on an experimental basis, this property at times introduces a factor of difficulty or error which is not to be lost sight of in the selection of the milk for such purposes. 35. Sources and control of bacteria in milk. — Most of the bacterial infection of milk is due to lack of care in handling. Some of the common sources ^ of con- tamination are : the air in the stable ; the cow's body ; the milker; the utensils; the method of handling the milk after it is drawn from the cow ; unclean cheese factory conditions. 1 Hiinziker, O. F., Germicidal action of milk, N. Y. (Cornell) Exp. Sta. Bui. 197. Stocking, W. A., Germicidal action of milk. Conn. (Storrs) Exp. Sta. Bui. 37, 1905. U. S. Treasury Dept., Hygienic Laboratory, Bui. 41, Milk and its relation to the public health, 1908, also revised as Bui. 56, 1909. 2 U. S. Dept. Agr., Farmers' Bui. ()02, Dairy Division, Pro- duction of clean milk, 1914. Lauder, A., and A. Cunningham, Some factors affecting the THE MILK IN ITS RELATION TO CHEESE 23 Since bacteria cause various kinds of fermentation, not only in the milk but in the products manufactured from it, the question of their control is of prime importance. There are two ways in which the bacterial growth in milk used for cheese-making may be controlled: (1) pre- vention of infection ; (2) the retardation of their develop- ment when present. The former is accomplished by strict cleanliness, the latter by adequate cooling. 36. The cow. — The body of the cow may be a source of bacterial contamination. Bacteria adhere to the hair of the animal, and to the scales of the skin, and during the process of milking these are very liable to fall into the milk. To prevent this, the cow should be curried to remove all loose material and hair. Just before milk- ing, the udder and flank should be wiped with a damp cloth ; this removes some of the material, and causes the remainder to adhere to the cow. 37. Stable air. — If the air of the stable is not clean, it will be a source of contamination. Particles of dust floating in the air carry more or less bacteria, and these fall into the milk during the process of milking. To bacteriological content of milk, Edinburgh and East of Scotland Coll. of Agr. Kept. XXVIII, 1913. Prucha, M. J., and H. M. Weeter, Germ content of milk, 111. Exp. Sta. Bui. 199, 1917. Harding, H. A., et al., The effect of certain dairy opera- tions upon the germ content of milk, N. Y. Exp. Sta. Bui. 365, 1913. Eraser, W. J., Sources of bacteria in milk, 111. Exp. Sta. Bui. 91, 1903. Frandsen, .1. H., Care of milk and cream on the farm, Neb. Exp. Sta. Bui. 133, 1912. Conn, H. W., The care and handling of milk, Conn. (Storrs) Exp. Sta. Bui. 26, 1903. Stocking, W. A., Jr., Quality of milk as affected by certain dairy operations. Conn. (Storrs) Exp. Sta. Bui. 42, 1906. 24 THE BOOK OF CHEESE keep the stable air free from dust at milking time, all operations which stir up dust, such as feeding, brushing the cows, cleaning the floor, should be practiced after milking or long enough before so that the dust will have settled. It is a good plan to close the doors and to sprinkle the floor just before milking. 38. The milker himself may be a source of contamina- tion. He should be clean and .wear clean clothing. The hands should not be wet with milk during milking. 39. Utensils. — The utensils are an important source of biU'terial contamination. The bacteria lodge in the Fig. 3. — Types of small-top milk pails. seams and corners unless these are well-flushed with solder. From these seams they are not easily removed. When fresh warm milk is placed into such utensils, the bacteria begin to grow and multiply. All utensils with which milk comes in contact should first be rinsed with cold water and then thoroughly washed and finally scalded with boiling water, and drained or blown absolutely dry. They should then be placed in an atmosphere free from dust until wanted for use again. If an aerator is used, this should be operated in pure air, free from odors and dust. One of the greatest sources of bacterial THE MILK IN ITS RELATION TO CHEESE '25 contamination of cheese milk is the use of the milk-cans to return whey to the farms for pig feed. Frequently, sour whey is left in the cans until ready to feed. These cans are then not properly washed and scalded. The practice of pasteurizing the whey at the cheese factory is a great help in preventing this source of infection and the spreading of disease. The use of a small-top milk pail ^ is to be especially recommended in preventing bacterial contamination. Because of the small opening, bacteria cannot easily fall into the milk in as large numbers as when the whole top of the pail is open. (See Fig. 3.) If a milking machine^ is used, great care must be exercised to see that all parts that come in contact with the milk are cleaned after each milking, and then put in a clean place until ready to use again. 40. The factory. — Another source of contamination is the cheese factory itself. The cheese-maker should keep his factory in the cleanest condition possible, not only because of the effect on the milk itself, but as a stim- ulus for the producers to follow his example. All doors and windows in the factory should be screened to keep out flies. 41. The control of bacteria. — If, in spite of preven- tive measures, bacteria get into the milk, their growth can be retarded by controlling the temperature. If the temperature of the milk, as soon as drawn, can be reduced 1 Harding, H. A., J. K. Wilson and G. A. Smith, Tests of covered milk pails, N. Y. Exp. Sta. Bui. ,326, 1910. Stocking, W. A., Tests of covered milk pails. Conn. (Storrs) Exp. Sta. Bui. 48, 1907. - Wing, L. W., Milking machines ; their sterilization and their efficiency in producing clean milk, N. Y. (Cornell) Exp. Sta. Circ. 18, 1913. 26 THE BOOK OF CHEESE below that at which the bacteria grow and multiply rapidly, it will retard their development. In general, all milk should be cooled to 50° F. or below. In cooling the milk, it should not be exposed to dust or odors. One of the best methods of cooling is to set the can containing the milk into a tub of cold running water, and then stir. If running water is not available, cold well-water ^ may be used, but the water should be changed several times. If the milk is not stirred during the cooling process, it will not cool so rapidly, because the layer of milk next the can will become cold and act as an insulator to the remainder in the center of the can. One way to destroy many of the bacteria in milk is by pasteurization. This consists in heating the milk to such a degree that the bacteria are killed, and then quickly cooling it. After pasteurization, the milk is so changed that some kinds of cheese cannot be made successfully. 42. Fermentation test. — When a cheese-maker is having trouble with gas in his cheese, or bad flavors, he can generally locate the source of difficulty. This can be done by making a small amount of cheese from each patron's milk, called a fermentation test." Pint or quart fruit jars or milk bottles make suitable containers. They should be thoroughly washed and scalded, to be sure they are clean and sterile, and then covered to pre- vent contamination. As the milk is delivered to the factory, a sample is taken of each patron's milk. The best way to secure the sample is to dip the sterile jar in the can of milk as delivered and fill two-thirds full of milk. iRuddiek, J. A., and G. H. Barr, The cooling of milk for cheese making, Ottawa Dept. of Agr. Bui. 22, 1910. 2 Wis. Exp. Sta. Rept. 189.5, pages 14-150, Fermentation test for gas-producing bacteria in milk. This is commonly called the Wisconsin curd test. THE MILK IN ITS RELATION TO CHEESE 27 The jars are then set in water at 110° F. to bring the temperature of the milk to 98° F. The jar should be kept covered. A sink or wash-tub makes a convenient place in which to keep the jars. When the temperature of the milk is 98° F., ten drops of rennet extract or pepsin is added to each jar. A uniform temperature of 98° F. should be maintained in the jars. This will necessitate the addition of warm water occasionally to the water sur- rounding the jars. When the milk is coagulated, the curd is broken up with a sterile knife. Precaution should be taken to sterilize the knife after using it in one jar before putting it into another. The best way to do this is to hold the knife for a minute in a pail of boiling water, after taking it out of each jar. The same precaution should be observed with the thermometer. Unless care is taken, contamina- tion is liable to be carried from one jar to the other. After cutting, the whey is poured off. The temperature should be kept at 98° F. so that the organisms wall have a suitable temperature for growth. The whey should be poured from the jars occasionally, usually about every half hour. As the fermentation takes place, different odors will be noticed in different jars. In ten to twelve hours the jar should be finally examined for odors and the curd taken out and cut to examine it for gas pockets. By this means, bad flavors and gas in the cheese can be traced to their sources. Fig. 4. • A gang sediment tester, one tester removed. 28 THE BOOK OF CHEESE 43. The sediment test. — The presence of solid material or dirt in the milk is always accompanied by bacterial contamination. By means of the sediment test, the amount of solid material can be determined. The test consists of filtering the milk through a layer of cotton ; the foreign material is left on the cotton filter. Various devices for filtering the milk have been manufactured. (Figs. 4 and 5.) In order to be able to compare the filters from the different dairy -men's milk, the same amount of each patron's milk is filtered, usually about a pint. These tests are usually made once or twice a month at the factory and the filters placed on a card where the dairy-men can see them. Much improvement in the quality of the milk has been accom- plished by the use of the sediment test. The purpose of this test may be and often is defeated by the use of effi- cient strainers. Milk produced in an unclean way may be rendered nearly free from sediment if carefully strained. It must be remembered that the strainer takes out only the undissolved substances and that bacteria and soluble materials which constitute a very large part of the filth pass through with the milk. Fig. 5. — A single sedi ment tester. CHAPTER III COAGULATING MATERIALS At the present time, two substances are used to coag- ulate milk for cheese-making, — rennet extract and com- mercial pepsin.^ Many substances will coagulate milk, such as acids and other chemicals. Enzymes in certain plants will also coagulate it. The curing or ripening of the cheese seems to depend on the physical and chemical properties of the curd, on the activity of certain organisms and on enzymes pro- duced by them or in the milk. Rennet extract and pepsin are the only known substances which will produce curd of such character as will permit the desired ripening changes to take place. Until recently, rennet extract was principally used to coagulate the milk, but because of the scarcity, pepsin is now being substituted. 44. Ferments. — Many of the common changes tak- ing place in milk are due to fermentations. The souring of milk is one of the most familiar cases of fermentation. 1 Stevenson, C, Pepsin in eheesemaking, Jour. Agr. (New Zeal.) 14 (1917), pages 32-34. Todd, A., and E. C. V. Cornish, Experiments in the prepara- tion of homemade rennet, Jour. Bd. Agr. (London) 23 (1916), no. 6, pages 549-555. Besana, C, Lack of coagulating ferment in eheesemaking, Staz. Sper. Agr. Ital. 49 (1916), pages 10-12. Van Dam, W., Rennet economy and substitutes, Verslag. Ver. Exploit. Proefzuivelboerderij. Hoorn, 1914, pages 45-46. 29 30 THE BOOK OF CHEESE The important change taking place is the formation of lactic acid from the milk-sugar. The change is brought about by certain living organisms, namely, the lactic acid- forming bacteria. Another familiar case of fermentation is the coagulation of milk by rennet extract or pepsin. In this case, the change is produced by a chemical sub- stance, not a living organism. Fermentation may be defined as a chemical change of an organic compound through the action of living organisms or of chemical agents. There are two general classes of ferments: (1) living organisms, or organized ferments; (2) chemical, or un- organized ferments. Organized ferments are living micro- organisms, capable, as a result of their growth, of causing the changes. Unorganized ferments are chemical sub- stances or ferments without life, capable of causing marked changes in many complex organic compounds, while the enzymes themselves undergo little or no change. These unorganized ferments are such as rennin, pepsin, trypsin, ptyalin. The rennet and pepsin must, there- fore, be very thoroughly mixed into the milk to insure complete and uniform results, because they act by con- tact, and theoretically, if they could be recovered, might be used over and over again. Practically, the amount used is so small a percentage that recovery would be impractical even if possible. 45. Nature of rennet. — Two enzymes or ferments are found in rennet extract, rennin and pepsin. They are prepared from the secreting areas of living membranes of the stomachs of mammalian young. For rennet- making, these stomachs are most valuable if taken before the young have received any other feed than milk. Ren- nin at this stage appears to predominate over pepsin COAGULATING MATERIALS 31 which is ah-eady secreted to some extent. With the inclusion of other feed, the secretion of pepsin comes to predominate. Rennin has never been separated entirely from pepsin. Both of these enzymes are secreted by digestive glands in the same area, perhaps even by the same glands. They are so closely related that many workers have regarded them as identical. In practical work the effectiveness of rennet preparations has been greatest when stomachs which have digested feed other than milk are excluded. The differences, therefore, however difficult to define, appear to be important in the commercial preparation of rennet. It was the practice until a few years ago for each cheese-maker to prepare his own rennet extract. Each patron was supposed to supply so many rennets. Now commercial rennet extract and pepsin are on the market ; however, some Swiss cheese-makers prefer to make their own rennet extract. For sheep's and goat's milk cheese, some makers hold that rennet made from kid or lamb stomachs is best for handling the milk of the respective species. The objection to the cheese-maker preparing his own rennet extract is that it varies in strength from batch to batch and is liable to spoil quickly. Taints and bad odors and flavors develop in it and so taint the cheese. 46, Preparation of remiet extract. — This extract may be manufactured commercially from digestive stomachs of calves, pigs or sheep. An animal is given a full meal just before slaughtering ; this stimulates a large flow of the digestive juices, containing the desired enzymes. The stomach is taken from the animal, cleaned, com- monly inflated and dried. It may be held in the dry con- dition until needed for use. Such stomachs are usually 32 THE BOOK OF CHEESE spoken of as " rennets " in the trade. Such old rennets may be seen to-day hanging from the rafters of some of the older cheese factories. When wanted for use, rennets are placed in oak barrels and covered with water. Before placing them in the barrel, they are cut open so that the water may have easy access. Salt is usuall}^ added to the water at the rate of 3 to 5 per cent. They are stirred and pounded in this solution from five to seven days. At the end of this time, they are wrung through a clothes- wringer to remove the liquid. The rennets are put back into a fresh solution of salt and water, the object being to obtain all the digestive juices possible. They are usually soaked from four to six weeks. At the end of this time, most of the digestive juices will have been re- moved. The liquid portion is passed through a filter made of straw, charcoal and sand. When clean, an excess of salt is added to preserve it. Such extracts cannot be sterilized by heat because the necessary temperature would destroy the enzyme. Effective disinfectants cannot be used in food products. The extract, therefore, should be kept cool to retard bac- terial growth. The extract is kept in wooden barrels, stone jugs or yellow glass bottles to protect it from light, which is able to destroy its activity. Rennet extract should be clear, with a clean salty taste and a distinct rennet flavor. There should be no cloudy appearance and no muddy sediment in properly preserved rennet. Rennet extract is on the market in the form of a liquid and a powder, the former being much more common. The commercial forms of rennet have the advantage in the skill used in their preparation and standardization. The combined product from large numbers of stomachs may not be as effective a preparation as the most skillfully COAGULATING MATERIALS 33 produced sample from the very choicest single stomach, but it gives a uniformity of result which improves the average product greatly. 47. Pepsin. — Pepsin is on the market in several commercial forms, as a liquid, scale pepsin and in a granular form known as spongy pepsin. Some commer- cial concerns put out a preparation which is a mixture of rennet extract and commercial pepsin. 48. Chemistry of curdling. — The chemistry of casein ^ and of curd formation under the influence of acid and rennet extract and pepsin has been the subject of many years' research. While many points remain unsettled, the general considerations together with a large mass of accepted facts may be presented and some of the unsolved problems pointed out as left for future researches. Casein is a white amorphous powder, practically insoluble in water. It is an acid and as such readily dissolves in solutions of the hydroxides or the carbonates of alkalies and alkaline earths by forming soluble salts. Pure casein salt solutions and fresh milk do not coagulate on boiling, but in the presence of free acid coagulation may take place below the boiling temperature. 1 T'he paragraphs on the chemistry of casein and on rennet action have been selected from a complete discussion of the subject by E. B. Forbes and M. H. Keith in Ohio Exp. Sta. Tech. Bui. 5 entitled, "A re\'iew of the literature of phosphorus compounds in animal metabolism." The original references cited in this discussion are given at the end of the chapter in the order of their citation in the text. See also, Van Slyke, L. L., and D. D. Van Slyke, I, The action of dilute acids upon casein when no soluble compounds are formed; II, The hydrolyses of the sodium salts of casein, N. Y. (Geneva) Exp. Sta. Tech. Bui. 3, pages 75-162, 1906. Sammis, J. L., S. K. Suzuki and F. W. Laabs, Factors control- ling the moisture content of cheese curds, U. S. Dept. Agr. Bur. An. Ind. Bui. 122, pages 1-61, 1910. D 34 THE BOOK OF CHEESE The t'oao;iiliiin formed in the ease of milk inekides fat and cak-ium j)hosphate. The shfi;ht i)elhek' which coats over milk when it is warmed is of the same comi)osition. 49. Use of acid. — A commonly accepted explanation of the precii)itati()n of casein by acids is that the casein is held in solution by chemical union with a base (lime in the case of milk) ; that added acid removes the base, allowing the insoluble casein to precipitate ; and that excess of acid unites with casein, forming a compound which is more or less readily soluble. 50. Robertson's theory. — According to Robertson's conception, in a soluble solution of a protein or its salt, the molecules of the protein unite with each other to a certain extent, in this way forming polymers. The re- action is reversible, and the iK)int of equilibrium between the compound and its polymeric modification varies under the infiuence of whatever condition affects the concentration of the protein ions. Addition of water, or of acid, alkali or salt, or the application of heat has such an effect, and consequently alters the relative num- ber of heavier ni()lecule-comj)lcxes. Robertson's experi- ments give evidence that one of the effects of increase of temperature on a solution of casein is a shifting of the eciuilibrium in the direction of the higher complexes. He explains coagulation as being a result of these molec- ular aggregates becoming so large as to assume the prop- erties of matter in mass and to become ])ractically an unstable suspension and then a precipitate. The acid curd then is casein or some combination of casein with the preci])itant acid. 51. Rennet curd. — Rennet extract and pepsin coagu- lation dilVcrs from coagulation by acids, and cannot be looked on as a simple removal of the base from a caseinate. COAGU LATINO MATERIALS 35 The presence' of soluble calcium salts (or other alkaline earth salts) seems to be essential, and the precipitate formed is not casein or a casein salt, but a salt of a slightly different nucleoalbumin called " paracasein." Many writers, following Halliburton, call this modification produced by rennin the " casein " and that from which it is derived, " caseinogen." Foster and a few others have used the term " tyrein " for the rennet clot. A number of investigations have been made on the conditions essential or favorable to formation of the coagulum, es])ecially with regard to the effects of the degree of acidity and of conditions affecting the amount of calcium present, either as free soluble salt or bound to the casein. Soluble salts of calcium, barium and stron- tium favor or hasten coagulation, while salts of ammonium, sodium and i)()tassium retard or i)revent coagulation. The bulk of the coagulum from milk is a calcium para- caseinate, but it carries down with it calcium phosphate and fat, both of which bodies have been helped to remain in their state of suspension in milk by the presence of the casein salt. Lindet (1912) has concluded that about one-half of the phosjjhorus contained in the rennet curd is in the form of ])hosphate of lime (probably tricalcic), the other half being organically combined phosphoric acid. 52. Hammarsten's theory. — According to Hammar- sten (1877, 1890), whose view has been commonly held, the distinctive effect of the ferment is not precipitation but the transformation of casein into paracasein. This is evidenced by the fact that if rennet be allowed to act on solutions free from lime salts no precipitate occurs ; but there is an invisible alteration of the casein, for now, even if the ferment be destroyed by boiling the solution. 36 THE BOOK OF CHEESE addition of lime salts will cause immediate coagulation. (See also Spiro, 1906.) Hence the process of rennet coagulation is a two-phase process ; the first phase is the transformation of casein by rennin, the second is the visible coagulation caused by lime salts. Furthermore, if the purest casein and the purest rennin were used, Hammarsten always found after coagulation that the filtrate contained very small amounts of a pro- tein. This protein he designated as the " whey protein," In accordance with these observations, Hammarsten (1911) explains the rennin action " as a cleavage process, in which the chief mass of the casein, sometimes more than 90 per cent, is split off as paracasein, a body closely related to casein, and in the presence of sufficient amounts of lime salts the paracasein-lime precipitates out while the proteose-like substance (whey-protein) remains in solution." By continued action of rennin on paracasein, a further transformation has been found in several cases (Petry, 1906; Van Herwerden, 1907; Van Dam, 1909), but perhaps due to a contamination of the rennin with pep- sin, or to the identity of these two enzymes. The action which forms paracasein and whey-protein takes place in a short time (Hammarsten, 1896 ; Schmidt-Nielson, 1906). The composition and solubilities of paracasein have received considerable attention. (See Loevenhart, 1904; Kikkoji, 1909; Van Slyke and Bosworth, 1912.) It is more readily digested by pepsin-hydrochloric acid than is casein (Hosl, 1910). 53. Duclaux theory. — Duclaux (1884) and Loeven- hart (1904) and others do not accept Hammarsten's theory ; but to most workers it seems probable, at least, that the action of the rennin is to cause a cleavage of COAGULATING MATERIALS 37 casein with formation of paracasein. However, the chemical and physical differences observed between casein and paracasein appear to be so slight that Loevenhart and some others think that they are only physical, per- haps differences in the size of the colloid or solution aggregates. Loevenhart conceives of a large part of the work of the rennet (or of the acid, in acid and heat coagu- lation) as being a freeing of the calcium to make it avail- able for precipitation. Some think that the aggregates of paracasein are larger than those of casein, but there is more evidence of their being smaller, which idea cor- responds with the findings of Bosworth, though he looks on the change as a true cleavage. 54. Bang's theory. — Another description of the pre- cipitation is given by Bang (1911), who studied the prog- ress of the coagulation process by means of interruptions at definite intervals. His observations confirm the idea that rennin causes the formation of paracasein, and that the calcium salt serves only for the precipitation of the paracasein ; the rennin has to do also with the mo- bilizing of lime salts. According to Bang, before coagu- lation occurs, paracaseins with constantly greater affinity for calcium phosphate are produced. These take up in- creasing amounts of calcium phosphate, until finally the combination formed can no longer remain in solution. 55. Bosworth's theory. — By a very recent work of L. L. Van Slyke and A. W. Bosworth (Van Slyke and Bosworth, 1912, 1913; and Bosworth and Van Slyke, 1913), in which ash-free casein and paracasein were com- pared as to their elementary composition, and as to the salts they form with bases, and the properties of these salts, it is indicated that the two compounds are alike in percentage composition and in combining equivalent, the 38 THE BOOK OF CHEESE paracasein molecule being one-half of the casein mole- cule. Moreover, Bosworth (1913) has shown that, if the rennin cleavage be carried out under conditions which avoid autohydrolysis, no other protein is formed ; also that, if the calcium caseinate present be one containing four equivalents of calcium, the paracaseinate does not precipitate, save in the presence of a soluble calcium salt, while, if the calcium caseinate be one of two equiva- lents of base, rennin does cause immediate coagulation. Bosworth concludes that the rennin action is a cleavage (probably hydrolytic) of a molecule of caseinate into two molecules of paracaseinate, the coagulation being a secondary effect due to a change in solubilities, dicalcium paracaseinate being soluble in pure water but not in water containing more than a trace of calcium salt, and the mono- calcium caseinate being insoluble in water. The alkali paracaseinates, as well as caseinates, are soluble. This explanation seems to promise to harmonize the observa- tions with regard to acidity and the effects of the presence of soluble salts. This theory represents, therefore, many years of continuous work at the New York Experiment Station centered primarily on American Cheddar cheese. Disputed points remain for further study but these workers have contributed much toward a clear descrip- tion of the chemical constitution of casein as affected by rennet action and bacterial activity. The investigations of these authors and of Hart with regard to the changes which the paracasein, the calcium and the phosphorus undergo during the ripening of cheese (Van Slyke and Hart, 1902, 1905; Van Slyke and Bos- worth, 1907, 1913; Bosworth, 1907) contributed to this interpretation. COAGULATING MATERIALS 39 Bang, Ivar, Ueber die chemisehe Vorgang bei der Milehgerin- nung diireh Lab, Skand. Arch. Physiol. 25, pages 105-144 ; through Jalu-esb. u. d. Fortseh. d. Thiercheni. 41, pages 221-222, 1911. BoswoRTH, A. W., The aetion of rennin on casein, N. Y. Exp. Sta. Tech. Bui. 31, 1913. BoswoRTH, A. W., Chemical studies of Camembert cheese, N. Y. Exp. Sta. Tech. Bui. 5, 1907. BoswoRTH, A. W., and L. L. Van Slyke, Preparation and com- position of basic calcium caseinate and paracaseinate, Jour. Biol. Chem. Vol. 14, pages 207-210, 1913. DucLAUx, Emile, Action de la presure sur le lait, Compt. Rend. Acad. Sci. 98, pages 526-528, 1884. Hammarsten, Olof, Zur Kenntnis des Caseins und der Wirkung des Labfermentes, Nova. Acta Regiae Soc. Sci. Upsaliensis in Memoriam Quattuor Saec. ab Univ., Upsaliensi Perae- torum, 1877. Hammarsten, Olof, Ueber das Verhalten des Paracaseins zu dem Labenzyme, Zeit. physiol. Chem. 22, pages 103-126, 1896. Hammarsten, Olof, A text book of physiological chemistry, from the author's 7th German edition, 1911. HosL, J., Untersehiede in der tryptischen und peptischen Spal- tung des Caseins, Paracaseins und des Paracaseinkalkes aus Kuh- und Ziegenmilch, Inaug. Diss. Bern., 31 pp., 1910. KiKKOji, T., Beitrage zur Kenntniss des Caseins und Paracaseins, Zeit. physiol. Chem. No. 61, pages 130-146, 1909. LiNDET, L., Solubilite des albuminoides du lait dans les elements du serum ; retrogradation de leur solubilite sous I'influ- ence du chlorure, Bui. Soc. Chim. (ser. 4) 13, pages 929- 935. LiNDET, L., Sur les elements mineraux contenus dans la caseine du lait. Rep. Eighth Internat. Congr. of Applied Chem. 19, 199-207, 1912. Loevenhart, a. S., Ueber die Gerinnung der Milch, Zeit. physiol. Chem. 41, pages 177-205, 1904. Petry, Eugen, Ueber die Einwirkung des Labferments auf Kasein, Beitrage z. Chem. Physiol, u. Path. 8, pages 339- 364, 1906. Robertson, T. Brailsford, On the influence of temperature upon the solubility of casein in alkaUne solutions, Jour. Biol. Chem. 5, pages 147-154, 1908. ScHMiDT-NiELSON, SiGVAL, Zur Kenutnis des Kaseins und der Labgerinnung, Upsala lakaref. Forh. (N. F.) No. 11, Suppl. 40 THE BOOK OF CHEESE Hammarsten Festschrift No. XV, 1-26 ; through Jahresb. u. d. Fortsehr. d. Thierchem. No. 36, pages 255-256, 1906. Spiro, K., Beeinflussung und Natur des Labungsvorganges, Beitrage z. Chem. Physiol, u. Path. 8, pages 365-369, 1906. Van Dam, W., Ueber die Wirkung des Labs Auf. Paracaseinkalks, Zeit. physiol. Chem. No. 61, pages 147-163, 1909. Van Herwerden, M., Beitrag zur Kenntnis der Labwirkung auf Casein, Zeit. physiol. Chem. 52, pages 184-206, 1907. Van Slyke, L. L., and A. W. Bosworth, I. Some of the first chemical changes in Cheddar cheese. II. The acidity of the water extract of Cheddar cheese, N. Y. Exp. Sta. Tech. Bui. 4, 1907. Van Slyke, L. L., and A. W. Bosworth, Composition and properties of some casein and paracasein compounds and their relations to cheese, N. Y. Exp. Sta. Tech. Bui. 26, 1912. Van Slyke, L. L., and A. W. Bosworth, Composition and properties of some casein and paracasein compounds and their relations to cheese, N. Y. Exp. Sta. Tech. Bui. 26, 1912. Van Slyke, L. L., and A. W. Bosworth, Method of preparing ash-free casein and paracasein. Jour. Biol. Chem. Vol. 14, pages 203-206, 1913. Van Slyke, L. L., and A. W. Bosworth, Preparation and com- position of unsaturated or acid caseinates and paracaseinates, Ibid. Vol. 14, pages 211-225, 1913. Van Slyke, L. L., and A. W. Bosworth, Valency of molecules and molecular weights of casein and paracasein. Ibid. Vol. 14, pages 227-230. 1913. Van Slyke, L. L., and A. W. Bosworth, Composition and prop- erties of the brine-soluble compounds in cheese. Jour. Biol. Chem. 14, pages 231-236, 1913. Van Slyke, L. L., and E. B. Hart, A study of some of the salts formed by casein and paracasein with acids ; their rela- tions to American Cheddar cheese, N. Y. Exp. Sta. Bui. 214, 1902. Van Slyke, L. L., and E. B. Hart, Casein and paracasein in some of their relations to bases and acids, American Chem. Jour. 33, pages 461-996, 1905. Van Slyke, L. L., and E. B. Hart, Some of the relations of casein and paracasein to bases and acids, and their applica- tion to Cheddar cheese, N. Y. Exp. Sta. Bui. 261, 1905. CHAPTER IV LACTIC STARTERS Acidity in cheese-making arises almost exclusively from the lactic acid produced from the fermentation of milk-sugar (lactose) by bacteria. Hydrochloric acid is used in the Wisconsin ^ process of making pasteurized milk cheese and sometimes for making skimmed-milk curd for baking purposes. It is regularly used in precipitat- ing casein not for food but for manufacturing purposes. 56. Acidifying organisms. — Many species of bacteria have been shown to possess the power to produce lactic acid by fermenting lactose. In practice, however, the cheese-maker seeks to control this fermentation by the actual introduction of the desired organisms and by the production of conditions which will insure this dominance through natural selection. For this purpose the initial souring for most types of cheeses is produced by some variety of the species originally described by Esten ^ and commonly referred to as Bacterium lactis-acidi, but variously named as B. acidi-lactici, Streptococcus lacticus, B. guntheri by different authors. Organisms of this series dominate all other species in milk which is in- ^ Saminis, J. L., and A. T. Bruhn, The manufacture of Cheddar cheese from pasteurized milk, Wis. Exp. Sta. Research Bui. 27, 1912. "^ Esten, W. M., Bacteria in the dairy, Conn. (Storrs) Rept. 1896, pages 44-52. 41 42 THE BOOK OF CHEESE cubated at 70° F. They produce a smooth sohd mass without a sign of gas holes and without the separation of whey from the curd, and develop in milk a maximum acidity of about 0.90 of one per cent when titrated as lactic acid. (For titration see Chapter V.) This species is usually present in small numbers in fresh milk. There are many varieties or strains of the species with differing rates of activity and measurable differences in acid pro- duced but with approximately^ the same qualitative characters. Most commercial starters for cheese- and butter-making belong to this group of species, although special mixtures with other organisms are prepared for special purposes. In addition to this group, most varieties of cheese contain some members of the colon- aerogenes group. When the milk is in proper condition, the activity of this group should b^ held in check by the early and rapid development of ncid. Free development of members of this group usually shows itself in the presence of gas holes in the curd. 57. Starter. — The practice of using pure cultures in cheese-making has brought about the development of factory methods of producing day by day cultures of the organisms desired, in quantities sufficient to inoculate the total quantity of milk used in manufacture. For this purpose milk is mostly used and the product is known as " starter." For cheese-making purposes, a starter is a substance used in the manufacture of dairy products having a predominance of lactic acid-forming micro- organisms in an active state. There are two general classes of starter: (1) Natural starter; (2) commercial starter. 58. Natural starter. — Milk, or other similar substance, which has become sour or in which large numbers of LACTIC STARTERS 43 lactic acid-forming organisms are present, is called a natural starter when used in the manufacture of dairy products. To secure clean-flavored milk, the cheese- maker usually selects the milk of some producer who usually brings good milk and allows it to sour natu- rally for use the next day. There is often a variation from day to day in the milk delivered by the same producer, so that the cheese-maker is not certain of a uniform quality in his fundamental material. While the lactic acid-forming organisms are developing, other organisms may also be present in numbers sufficient to produce bad flavors. If a starter has any objectionable flavor, it should not be used. Natural starters very commonly develop objectionable flavors which at first are very difficult to recognize. When natural starters with objectionable but not easily recognizable odors are used, the effect may be seen on the cheese. Milk, sour whey and buttermilk are materials commonly used as natural starter. A common difficulty in skimmed-milk cheese is caused by the use of buttermilk as a starter. 59. Commercial starter or pure cultures. — The alter- native practice consists in the introduction of pure cul- tures of known strains of lactic bacteria into special milk to make the starter. Since these cultures must be pre- pared by a bacteriologist, commercial laboratories have developed a large business in their production. Many such commercial brands are manufactured under trade- marked names. Some of these cultures represent races of lactic bacteria cultivated and cared for efficiently, hence uniformly valuable over long periods of time. Others care- lessly produced are worthless, or even a peril to the user. These organisms are usually shipped in small quantities in bottles of liquid or powder, or in capsules of uniform 44 THE BOOK OF CHEESE size. The contents may be either the culture medium upon which the organisms grew or inert substance designed merely to hold the bacteria in inactive form. In either solid or liquid form, the producer of the culture should guarantee its activity up to a plainly stated date. It is the problem ^ of the cheese-maker or butter-maker to increase this small amount of lactic acid-forming or- ganisms to such numbers and in such active condition that it may be used in the f actor}' ; while being built up, these organisms must be kept pure. The usual prac- tice is to allow them to develop in some material, usually whole milk or skimmed-milk ; dissolved milk powder may be used in the place of milk. 60. Manufacturer's directions. — The manufacturer usually sends directions with his starter preparation, telling how it should be used to secure the best result. These directions apply to average conditions and must be varied to suit the individual instances so that a good starter will be the result. The directions usually state the amount of milk necessary for the first inoculation. It is usually a small amount, one or two quarts. After the specific kmount has been selected, this milk should be pasteurized. 61. Selecting milk. — The milk for use in starter- making should be selected with very much care. Only clean-flavored sweet milk, free from undesirable micro- ^ Bushnell, L. D., and W. R. Wright, Preparation and use of butter starter, Mich. Exp. Sta. Bui. 246, 1907. Hastings, E. G., Preparation and use of starter. Wis. Exp. Sta. Bui. 181, 1909. Larsen, C, and W. White, Preparation and use of starter, S. D. Exp. Sta. Bui. 123, 1910. Guthrie, E. S., and W. W. Fisk, Propagation of starter for butter-making and cheese-making, N. Y. (Cornell) Exp. Sta. Circ. 13, 1912. LACTIC STARTERS 45 organisms, should be used iu the preparation of starter. The milk is ordinarily chosen from a producer whose milk is usually in good condition. The quality of the milk can be determined by the use of the fermentation test. (See Chapter II.) It is better to choose only the morning's milk for the making of starter, because the bacteria have not had so much opportunity to develop. In no case should the mixed milk be used in the preparation of starter, as this eliminates all oppor- tunity for selection. The flavor of the starter will be the same as that of the milk from which it is made. 62. Pasteurization is the process of heating to a high temperature for a given length of time and quickly cool- ing. It kills most of the micro-organisms in the milk. In other words, it makes a clean seed-bed for the pure culture. The temperatures of pasteurization recommended for starter-making diflFer with the authority. A temperature of 1S0° F. for thirty minutes or longer seems to be very satisfactory, since under these condi- tions nearly all the micro-organisms in the milk are killed. 63. Containers. — Various kinds of containers may be used for starter-making. One-quart glass fruit jars or milk bottles make very satisfactory containers, because the condition of the starter may be seen at any time. They are also easily cleaned. They have the disad- vantage, however, of being easily broken, if the tem- perature is suddenly changed, or if severely jarred. Tin containers may also be used. Such containers are not easily broken, but they are harder to clean and must be opened to examine the contents ; hence the liability of contamination is very much greater. This small amount of milk may be pasteurized by plac- ing the container in water heated to the desired tempera- 46 THE BOOK OF CHEESE ture. A very satisfactory arrangement is to cut off a barrel, and place a steam pipe in it. The barrel can then be filled partly full of water and heated by steam. The bottles of milk to be pasteurized are hung in the water in the barrel. Two or three more bottles should be prepared than it is expected will be used as some of the bottles are liable to be broken while cooling or heating. The bottles should be filled about two-thirds full. This leaves room enough to add the mother starter and later to break up the starter to examine it. It is desirable not to have the milk or starter touch the cover since contaminations are more likely. It is a good plan when pasteurizing to have one bottle as a check. This may be filled with water and left open and the thermometer placed in it. A luiiform temperatiu'e may be obtained by shaking the bottles. 64. Adding cultures. — After being pasteurized, the milk should be cooled to a temperature of 80° F. This is a suitable temperature for the development of the lactic acid-forming organisms. The commercial or pure culture should now be added to the milk at the rate specified in the directions. Care should be exercised in opening bottles not to put the covers in an unclean place, A sterile dipper is a good place to put them. After the culture has been added to the milk, it should be mixed thoroughly by shaking the bottle. This should be re- peated every fifteen or twenty minutes for four or five times. This is done to make certain that the culture is thoroughly mixed with the milk. The milk should be placed in a room or incubator as near 80° F. as pos- sible, in order to have a uniform temperature for the growth of the organisms. The bacteria in the pure culture are more or less dormant so that a somewhat LACTIC STARTERS 47 higher temperature than the ordinary is necessary to stimulate their activity. This milk should be coagulated in eighteen to twenty-four hours, depending largely on the uniformity of the temperature during incubation. 65. Cleanliness. — To produce a good starter, great care should be exercised that all utensils coming in contact with the milk are sterile. After the milk is in the container in which the starter is made, it should be kept covered as continuously as possible. Thermometers should not be put into it to ascertain the temperature. When examining the starter, do not dip into it, but pour out, as this prevents contamination. The cover, when removed from the container, should be put in a sterile place in such way that the dirt will not stick to it and later get into the starter. 66. " Mother " starter or startoline. — The thickened sour milk obtained by inoculating the sweet pasteurized milk with pure culture of lactic acid-forming bacteria is known as " mother starter " or " startoline." 67. Examining starter. — This starter should be ex- amined carefull\' as to physical properties, odor and taste. The coagulation should be smooth, free from whey and gassy pockets or bubbles. Sometimes the first few m- oculations from a new culture will show signs of gas, but, usually, this will quickly disappear, and not injure the starter. It should have a clean sour cream odor and clean, mild, acid flavor. After breaking up it should be thick and creamy, entirely free from lumps. This starter may have an objectionable flavor, due to the media in which the organisms were growing when shipped. In such cases it is necessary to carry the starter one or two propagations to overcome the flavor, to enliven the micro-organisms and to secure the quantity desired. 48 THE BOOK OF CHEESE 68. Second day's propagation. — For the second day, the milk for the starter is selected as on the first day. It is pasteurized, and this time cooled to 70° F. The milk is cooled a trifle colder the second day than the first, because the organisms have become more active and hence do not require as high a temperature to grow. Instead of inoculating with powder, as was done the first day, the mother starter prepared the first day is used. This requires only a very small amount, perhaps a tablespoonful to a quart bottle. It should be thor- oughly mixed with the milk. This starter may have the flavor of the media used in the laboratory culture, therefore may need to be carried one or two days more to eliminate it. After the flavor has become nor- mal, the mother starter is ready for commercial use. 69. Preparation of larger amount of starter. — The first thing to determine is the quantity of starter re- quired. As much milk should be carefully chosen as the amount of starter desired. This milk should then be pasteurized. An improved starter-can (Fig. 6) may be used in the pas- teurization of the milk and the making of starter, or a milk-can (Fig. 7) placed in a tub of water in which there is a steam pipe. The former requires mechanical power to operate the agitator, but the latter can be used Fig. 6. — An improved starter-can. LACTIC STARTERS 49 7. — A simpls device for preparation of starter. the where mechanical power is not available. In the latter the milk and starter are stirred by hand. This is the kind of apparatus more often found in cheese factories. If possible, this milk should be pasteurized to 180° F. for thirty minutes ; this kills most of the bac- teria and spores. The milk should be cooled to 60°-65° F., the tempera- ture of incubation. This temperature may be varied with conditions, so that the starter will be ready for use at the desired time. The higher the temperature, the less time is required to ripen the starter. 70. Amount of mother starter to use. — The mother starter prepared the day before is now used to inoculate the starter milk. The amount to use will depend on : 1. Temperature of milk when mother starter is added ; 2. Average temperature at which the milk will be kept during the ripening period ; 3. Time allowed for starter to ripen before it is to be used ; 4. Vigor and acidity of the mother starter added. There is a very wide range as to the amount of mother starter required, from 0.5 of one per cent to 10 per cent being used under different conditions. Some operators prefer to add the mother starter while the milk is at a temperature of about 90° F., before it has been cooled to the incubating temperature. This reduces the amount of mother starter necessary. 50 THE BOOK OF CHEESE If ail even incubating temperature can be maintained, it will require less mother starter than if the temperature goes down. If the ripening period is short, it will require a larger amount of mother starter, than if the ripening period is longer. If the starter has a low acidity or weak body indicating that organisms are of low vitality, it will re- quire more mother starter. 71. Qualities. — The starter, when ready to use, may or may not be coagulated ; a good idea of the quality of the starter may be gained by the condition of the coagu- lation. The coagulation should be jelly- or custard-like, close and smooth, entirely free from gas pockets and should not be wheyed off. When broken up, the starter should be of a smooth creamy texture and entirely free from lumpiness or wateriness. It should have a slightly pronounced acid aroma. The starter should be free from taints and all undesirable flavors; I'l? flavor should be a clean, mild acid taste. 72. How to carry the mother starter. — Some mother starter must be carried from day to day to iiioculate the large starter. This may be carried or made in several ways : 1 . Independently : By this method a mother starter is made and carried entirely separately from the large starter. It requires more time and work, but is by far the best method. With a good mother starter, there is not so much danger of the larger starter becoming poor in quality. 2. Mother starter may be made by dipping pasteurized milk from that pre])ared for the large starter with sterile jars and then inoculating these jars separately. By LACTIC STARTERS 51 this method, if the milk selected for the large starter is poor, the mother starter for the next day will be the same. It is very difficult by this method to carry a uniform, high quality mother starter. There is danger that the container used for the mother starter may not be sterile, and there is also danger of contamination in transferring the milk. 3. Another practice is to hold over some of the large starter used to-day for mother starter. This is by far the easiest method. By this practice, there is no cer- tainty of the quality of the starter, because there is little or no control of the mother starter. If the large starter is for some reason not good, there is no separate reserve of mother starter on which to rely. 73. Starter score-cards. — The use of a score-card tends to analyze the observations in such a way as to emphasize all the characteristics desired in the starter. Such an analysis seeks to minimize the personal factor and pro- duce a standardization of the quality. The score-card finally reduces the qualities of the starter to a numerical basis for ease of comparison. Many score-cards have been proposed but the one preferred by the authors is that used by the Dairy Department of the New York State College of Agriculture, which is as follows : Cornell Score-card Flavor 50 Clean, desirable acid. Aroma 20 Clean, agreeable acid. No undesir- able aroma. Acidity 20 0.6 per cent-0.8 per cent. Body 10 Before breaking up : jelly-like, close, absence of gas holes. No free whey. After breaking up : smooth, creamy, free from gran- ules or flakes. 52 THE BOOK OF CHEESE The qualities mentioned in this score-card can be quickly and easily determined by examining and tasting the starter and by making an acid test of a sample. The acid test is conducted as with milk (see Chapter II) ex- cept the starter must be rinsed out of the pipette with pure water. Some starter score-cards call for a bacterial examination and counting of the starter organisms. This takes a considerable period of time and is not entirely necessary. The physical properties and acid test are closely correlated with the presence of the desired organ- isms. 74. Use of starter. — If all milk could be clean and sweet and the only fermentation from it were the clean acid type, a starter would be useless. Such milk is hard to obtain ; therefore, a starter is used to overcome the bad fermentation. This improves the flavor, body and tex- ture of the cheese. The common contaminations which the starter will tend to correct are : 1. Gas-producing bacteria. 2. Yeasts. 3. Bad flavors or taints. The length of time a starter may be carried depends on the accuracy and carefulness of the maker. This calls for scrupulous attention to the temperature, the selection of milk and keeping out contaminations. The maker must remember that a starter is not merely milk, but milk full of a multitude of tiny plants, very sensi- tive to food, temperature, clean surroundings and the quantity of their own acid. 75. The amount of starter to use depends on the amount of acid desired in the milk for any particular kind of cheese. The great abuse of starter is the practice LACTIC STARTERS 53 NEW YORK STATE COLLEGE OF AGRICULTURE AT CORNELL UNIVERSITY STARTER LOT-CARD Department of Dairy Industry. Day and Date MILK: Kind % fat % solids not fat.- Flavor Amount of milk Hours old._ PASTEURIZATION : Method Milk when received : Temperature Acidity % Heating : Turning on heat APM. Desired temp, reached APM. Turning off heat APM. Length of time at desired temp — Beginning to cool Cooled .APM ; to Acidity : After pasteurization When inoculated INOCULATION: Time Temperature Amount -.. lbs % INCUBATION : Temperatvue Time MOTHER STARTER USED: Source % used..._ Times propagated Acidity..._ Amount used._ Appearance Flavor Comments.. - STARTER : Time of examining Temperature - Flavor 50 Aroma 20 Acidity 20 Body._ 10 Total 100 SCORE-CARD : Clean, desirable acid. Clean, agreeable acid. No undesirable aroma. 0.6%-0.75%. Before breaking up : jelly-like, close, absence of gas holes. No free whey. —After breaking up : smooth, creamy, free from granules or flakes. The above is a tentative score-card. COMMENTS : Work and observation "by.. 54 THE BOOK OF CHEESE of using too much. It is better and safer to add starter a little at a time and several times than to add too much at once. When starter is added to milk for cheese-making, it should be strained to remove any lumps ; otherwise an uneven color is likely to result. 76. Starter lot-card. — For certain dairy operations, a permanent record is desired. This is especially true in the making of starter and certain varieties of cheese, A lot-card not only serves as a record but also points out the succeeding steps of the operation. This latter is especially useful for beginners and students. Page 53 shows a desirable lot-card to be used when making starter. Each operation has been referred to the page in the text where it is discussed. This makes this particular lot-card an index to the whole process of starter- making as here treated. CHAPTER V CURD-MAKING Aside from the purely sour-milk cheeses, the coag- ulum or curd resulting from rennet action is the basis of cheese-making. The finished cheese, whatever its final condition, is primarily dependent on a particular chemical composition and fairly definite physical char- acters in the freshly made curd mass. These characters are determined by a series of factors under control of the cheese-maker. Assuming the milk to be normal in character, success depends on the use of a proper combina- tion of these factors. The possible variations in each factor together with their number makes an almost in- finite series of such combinations possible. The essential steps in the process are, therefore, presented as under- lying all cheese-making. The special adaptations of each factor are considered in the discussion of the vari- eties group by group. These factors follow : A. The coagulation group: 1. Fat-content of the milk. 2. The acidity of the milk. 3. The temperature of renneting. 4. The effective quantity of rennet. 5. Curdling period or the time allowed for rennet action. 55 56 THE BOOK OF CHEESE B. The handling group : 6. Cutting or breaking the curd. 7. Heating (cooking) or not heating. 8. Draining (including pressing, grinding and putting into hoops or forms). 77. The composition of the milk. — The fat percentage in the milk in the cheese-vat should be known to the cheese-maker and be strictly under his control. The fat tester and the separator make this clearly possible. He can go further. Milk from particular herds whose quality is a matter of record from the routine test of each patron's milk may be selected and brought together for the manu- facturer of cheese of special quality. Control of casein or lactose, on the contrary, is not nearly so practicable. The purchase of milk on the fat test has become so well established in most dairy territories, as to insure the presence and constant use of the tester. A fat test of the mixed product in the cheese- vat in connection with estab- lished tables thus insures an accurate knowledge of the materials which go into each day's cheese. For some varieties of cheese, whole milk should always be used. For other varieties, the addition or removal of fat is regularly recognized as part of the making process. The presence of added fat or the removal of fat affects the texture of the product and the details of the process of making. 78. Cheese color. — An alkaline solution of annatto is usually used as a cheese color. This colors both casein and fat in contrast to butter color which is an oil solution of the dye and mixes only with the fat. Cheese color is added to the milk in making some varieties of cheese, and not for others. When lactic starter is used, CURD-MAKING 57 the color should be added after the starter and just before the addition of the rennet. The amount is determined by the color desired in the cheese. The usual amount varies from one to four ounces to each thousand pounds of milk. Before adding, the color should be diluted in either milk or water, preferably water. It should then be mixed thoroughly with the milk. 79. The acidity factor. — JNIilk as drawn shows a meas- urable acidity when titrated to phenolphthalein with normal sodium hydroxide. This figure varies with the composition of milk. Casein itself gives a weakly acid reaction with this indicator. Calculated as lactic acid, this initial acidity varies within fairly wide limits, records being found from 0.12 to 0.21 of one per cent or even more widely apart. .Commonly, however, such titration shows 0.14 to 0.17 per cent. Some forms of cheese (Limburger, Swiss, Brie) are made from absolutely fresh milk. Acidity from bacterial activity is important as a factor in the making of most types of cheese and probably in the ripening of all types. Increasing the acidity of the milk hastens rennet action and within limits produces increased firmness of the curd. If carried too high, acidity causes a grainy or sandy curd. Normally fresh milk is sufficiently acid in reaction when tested to phenolphthalein to permit rennet to act, but the rate of action increases rapidly with the develop- ment of acid. Increase of acidity may be accomplished : (a) by the addition of acid as has been done by Sam- mis ^ and Bruhn in pasteurized milk for Cheddar cheese; or (b) by the development of acid through the 1 Sammis, J. L., and A. T. Bruhn, The manufacture of cheese of the Cheddar type from pasteurized milk, U. S. Dept. Agr. Bur. An. Ind. Bui. 165, pages 1-95, 1913. 58 THE BOOK OF CHEESE activity of lactic orfi;anisms, which is the usual way. For rennetiiig, the acidity necessary for particular cheeses runs from that of absolutely fresh milk still warm (as in French Brie, Limburger, Swiss, Gorgonzola) through series calling for increase of acidity, hundredth by hun- dredth per cent calculated as lactic acid. This ranges from 0.17 to 0.20 per cent as is variously used in Ameri- can factory Cheddar to about 0.25 to 0.28 per cent as obtained by adding acid in Sammis' method. This method is discussed under the heading " Cheddar Cheese from Pasteurized Milk " (p. 229) since it requires special apparatus and has not thus far been used with other types of cheese. For the development of acidity by the action of bacteria, lactic starter is almost universally used. This may be added in very small quantities and the acidity secured by closely watching its development or by adding starter in amount sufficicmt to obtaiti the re- ((uired acidity at once. In either case, the cheese-maker needs to know the rate of action of the culture to in- sure the proper control of the process. The amount of acid already present when the rennet is added affects not only the texture of the curd as first found, but within limits indicates also the rate at which further acidity may be expected to de^•cl()p. A series of experiments in making Roquefort were tabu- lated to show the rate of acidification from various initial ])oints. In the graphs (Fig. 8) the curves for acid de- velopment are parallel after the determination reaches 0.30 per cent. These experiments were made at a tem- I^erature 80° to 84° F. Milk at the lowest acidities tried developed titratable acid very slowly. A period of several hours was required to produce sufficient acid to affect the curd texture. When the acid reached 0.25 per cent by titra- CURD-MAKING 59 tion, the further rise was rapid and all the lines became almost straight and parallel after the titration reached 0.30 .55 / 45 / ^ / 1/, 40 // \j // / .35 // C^ ^ .30 ^ / /C^ /J^ Y / .25 /^^ ^ y- y .20 /^ ^^^"l ____ ^ y^ ^="=^ j— ■ 1 1 15 1 Fig. 8. 2 3 4 5 6 • The acidification of Roquefort cheese. per cent. If this rapid souring occurred after the comple- tion of the cheese-making process, the texture of the experimental cheese was not measurably affected. In those cases, however, in which 0.30 per cent was reached before the cheese reached its final form in the hoop, the 60 THE BOOK OF CHEESE texture of the ripened cheese was entirely different from that desired for this variety under experiment. These curves apply directly to but one cheese process in which a particular combination of acidity, rennet and time is used to obtain a very delicately balanced result. In other varieties it is equally important to obtain exactly the ad- justment of these factors which will bring the desired result. 80. Acidity of milk when received. — If proper care has been taken, milk should be delivered to the factory fresh, clean and without the development of acid. If the milk has not been handled properly, the early stages of souring or some other unfa^'orable fermentation will have de\'eloped. Such milk may develop too much acid, or gas, or any one of several objectionable flavors during the making and ripening of the cheese. Some cheese-makers become very expert in detecting the first traces of objectionable qualities, but most makers are dependent on standartlized tests to determine whether milk shall be accepted or rejected, and when accepted to determine the rate at which it may be expected to respond during the cheese-making process. Various tests have been devised to determine the amount of acid present in milk. There are two tests commonly used in cheese-factories. One is knowai as the " acid test " and the other the " rennet test." 81. The acid test^ is made by titrating a known amount of milk (Fig. 9) against an alkali solution of ^ Publow, C. A., An apparatus for measuring acidity in cheese- making and buttermaking, Cornell Exp. Sta. Cire. 7, pages 17— 20, 1909. Hastings, E. G., and A. C. Evans, A comparison of the acid test and the rennet test for determining the condition of milk for the Cheddar tvpe of cheese, U. S. Dept. Agr. Bur. An. Ind. Circ. 210, pages 1-6, 1913. CURD-MAKING 61 known strength, using phenolphthalein as an Indi- cator. The object of the indicator is to tell the con- dition of the milk, whether it is acid, alkaline or neutral. The indicator does not change in an acid solution but turns pink when the solution is or becomes alkaline. To make the test, a known quantity of the material to be tested is placed in a white cup, and to this several drops of indicator are added. As an indi- cator, a 1 per cent solu- tion of phenolphthalein in 95 per cent alcohol is commonly used. As an alkali solution, sodium hydroxide (NaOH) is used in the standardized strength usually either tenth (N/10) normal or twentieth (N/20) normal. This solution should be obtained in some one of the standardized forms commercially prepared. The alkali is added, drop by drop, from a gradu- ated burette until a faint pink color appears. This shows that the acid in the milk has been neutralized by the alkali. The amount of alkali that has been used can be determined from the burette. Knowing the amount of milk and alkali solu- tion used, it is easy to calculate the amount of acid in the substance tested. The results are usually expressed Fig. 9. — An acid tester. 62 THE BOOK OF CHEESE either as percentages of lactic acid or preferably as cubic centimeters of normal alkali required to neutralize 100 or 1000 c.c. of milk. This kind of test is on the market under different names, such as Mann's, Publow's, Far- rington's and INIarschall's. 82. Rennet tests. — Several rennet tests have been devised, but the one most widely used is the Marschall (Fig. 10). This consists of a 1 c.c. pipette to measure the rennet extract, a small bottle in which to dilute the extract, a special cu]) to hold the milk and a spatula to mix the milk with the rennet extract. This cup has on ^(^ the inside from top to bottom a scale graduated from at the top to 10 at the bot- tom. There is a hole in the bottom to allow the milk to run out. 83. Marschall rennet test. — To make a Marschall rennet test, 1 c.c. of rennet extract is measured, with the 1 c.c. pipette, and placed in the bottle. Care should be exercised to rinse out the pipette. The bottle is then filled to the mark with cold water. After the milk has been heated to the setting temperature, 84°- 86° F., the cup is filled with milk and set on the edge of the vat so that the milk running out through the hole in the bottom of the cup will flow into the vat. Just as the surface of the milk reaches the mark on the cup, the diluted rennet extract is added and thoroughly mixed Fiu. lU. — Marscliali rennet test. CURD-MAKING 63 with the milk, using the small spatula to stir it. The rennet and milk should be mixed until it has run down at least one-half space on the scale in the cup. As the rennet begins to coagulate the milk, it runs slower from the hole in the bottom of the cup, until it finally stops. When it stops, the point on the scale indicated by the surface of the coagulated milk is noted. The test is recorded by the number of spaces the surface of the milk lowers from the time the rennet is added until it is coagulated. This test depends on three factors : the strength of the rennet extract, the temperature of the milk, the acidity of the milk. The more acid, the quicker the milk will coagulate. To measure any one of these factors, the other two must be constant. The variable factor is the acidity of the milk. This test will not indicate the percentage of acid in the milk, but is simply a comparative test to be used from day to day; for example, if the rennet test to-day shows three spaces, and the operator makes that milk into cheese and the process seems to be normal, it shows that for good results in this factory, milk should be ripened to show three spaces every day. If the next day the milk showed four spaces, it should be allowed to ripen more until it shows three spaces. If it shows only two spaces, this indicates that the milk has too much acid development or is over- ripe. A cheese-maker will have to determine at what point to set his milk, because the test will vary from one factory to another. 84. Comparison of acid and rennet test. — Each of these tests has its advantages and disadvantages. The advantage of the acid test is that it can be made as well of warm as cold milk. This is of gr&at impor- tance in determining whether the milk delivered by any 64 THE BOOK OF CHEESE patron is too ripe to be received. The acidity of other materials, such as whey and starter, can be determined as well as that of milk. The disadvantages are that it is difficult to get the alkali solution of the proper strength and the solution is liable to deteriorate on standing. It requires a careful exact operator to make the test. The advantages of the rennet test are that it is easy to make, and it requires no materials that are hard to re- place. The disadvantage is that the milk must be warmed to the same temperature before a comparative test can be made. The size of the outlet in cups varies. It does not indicate the percentage of acid present in the milk. It is simply a comparative test. To obtain the best result, both tests should be used in conjunction. 85. Control of acid. — The control of acidity in curd and cheese is dependent on the control of the moisture or water-content. The control of both factors is very impor- tant in relation to the quality ^ of the cheese. Often acid- ity is spoken of when moisture is realh' intended, and vice versa. The close relation between the moisture and acidity is due to the presence of the milk-sugar in solution in the milk-serum which becomes the whey of cheese- making. Water or moisture in cheese consists of the remnant of this whey which is not expelled in the making process. During manufacture and the ripening process, the milk-sugar is changed to lactic acid. A cheese may be sweet when first made and after a time become sour because it contains too much moisture in the form of whey. Excess of whey carries excess of milk-sugar from which fermentation produces intense acidity. ^ Doane,. C. F., The influence of lactic acid on the quality of cheese of the Cheddar type, U. S. Dept. Agr. Bur. An. Ind. Bui. 123, pages 1-20, 1910. CURD-MAKING 65 Various tests have been devised to determine the amount of acid developed at the different stages of manu- facture. These tests are described on page 61. By the use of such tests, the development of acid during the manufacturing process can be very accurately determined. There is no quick, accurate test to determine the amount of moisture in the curd. The cheese-maker has to rely on his own judgment, guided largely by the appearance, feeling and condition of the curd. After the rennet extract has been added, all control of the acid development is lost. The cheese-maker can determine rather accurately how fast the acid will de- velop during the ripening of the milk. This shows the importance of the proper ripening. The amount of acid developed during the different stages of the manufactur- ing process can be approximately followed with the various acid tests. The manufacturing process should then be varied to obtain the proper relation between the moisture and the acid present. The only time that the acidity may be controlled is when the milk is being ripened. If too much acid is developed before the rennet is added, there is apt to be too much acid at each stage of the manu- facturing process. This is liable to hurry the cheese- making process and to cause a loss, both in quality and quantity of cheese, and may cause a high acid or sour cheese. If sufficient acid is not developed at the time the rennet is added or if the milk is not sufficiently ripened, the acid is liable not to develop fast enough so that there will not be sufficient at each step in the cheese-making process. Such a cheese is called " sweet." There are several conditions which will cause an over-development of acid. Such a cheese is called " acidy " or " sour." These factors are within the control of the cheese-maker. 66 THE BOOK OF CHEESE hence should be avoided. A sour cheese shows lack of skill and care on the part of the cheese-maker. Conditions causing an acidy or sour cheese: Receiving sour or high acid milk at the cheese-factory. Use of too much starter. Ripening the milk too much before the rennet is added. Removing the whey before the curd is properly firmed, hence leaving it with too much moisture. Development of too much acid in the whey before the whey is removed. Improper relationship between the moisture and acidity at the time of removing the whey. Conditions causing deficient acid: Adding the rennet before sufficient acid has developed. Not using sufficient starter. Not developing sufficient acid in the whey. 86. Acidity and rennet action. — The rennet extract acts only in an acid medium. The greater the acid de- velopment, within certain limits, the faster the action of the rennet. If enough acid has developed to cause a coagulation of the casein, the rennet will not coagulate the milk. This is one reason why Cheddar cheese cannot be made from sour milk. 87. Acidity and expulsion of the whey. — The con- traction of the curd and expulsion of the whey are so closely related that they may be treated under the same heading. The more acid, the faster the whey separates from the curd, other conditions being uniform. The relation of acidity and firmness of the curd to temper- ature of the curd is another important factor in the suc- cessful manufacture of cheese. The higher the acidity, the faster the temperature of the curd can be raised with- CURD-MAKING 67 out any harmful effects. If the temperature is raised too fast in relation to the acidity, the film surrounding each piece of curd will become toughened so that the moisture will not be able to escape. When this condition exists, the curd will feel firm but when the pieces are broken open the inside is found to be very soft. This results in a large loss later or may cause a sour cheese. It usually causes an uneven texture and color in the cheese. 88. Acidity in relation to cheese flavor. — Just what part the acid plays in the development of cheese flavor is not known. If a certain amount of acid is not present, the characteristic cheese flavor does not develop. If too much acid is developed, it gives the cheese a sour flavor which is unpleasant. If sufficient acid is not developed, the other undesirable factors seem to be more active, causing very disagreeable fla^'or and may cause the cheese to putrefy. A cheese with a low acid usually develops a very mild flavor, and if carried to extremes, as in the case of some washed curd cheese, the true cheese flavor never develops. 89. Acidity in relation to body and texture of cheese. — If a cheese is to have a close, smooth, mellow^ silky body and texture, a certain amount of acid develop- ment is necessary. If too much acid is developed, the body and texture will be dry, harsh, sandy, mealy, corky. If the acid is not sufficient the cheese may be soft or weak bodied, and is usually characterized by " Swiss curd holes," which are spaces of various sizes usually more or less round and very shiny on the inside. 90. Acidity in relation to cheese color. — An over- development of acidity affects the color of a cheese. If this development of acidity is uniform throughout the cheese, it causes the color to become pale or bleached. 68 THE BOOK OF CHEESE If this development is uneven, due to the uneven distri- bution of moisture, the color will be bleached in spots, causing a mottled effect. 91. Control of moisture.^ — The cheese-maker must use skill and judgment in regulating the amount of mois- ture in relation to the firmness of the curd and the acid. Since there are no quick accurate tests to determine the amount of moisture, this is left entirely to the judg- ment of the operator. Certain methods of handling the curd reduce the moisture-content, while others in- crease it. The cheese-maker must decide how to handle the curd. If the curd becomes too dry, methods should be employed to increase the moisture, and vice versa. Causes of excessive moisture: Cutting the curd coarse. Cutting the curd after it has become too hard. Setting the milk at a high temperature. Use of excessive amount of rennet extract. Low acid in the curd at the time of removing the whey. Not stirring the curd with the hands as the last of the whey is removed. High piling of the curd during the cheddaring process. Piling the curd too quickly after removing the whey. Use of a small amount of salt. Holding the curd at too low a temperature after the whey is removed. Soaking the curd in water previous to salting. Allowing the curd to remain in the whey too long so that it reabsorbs the whey. Heating the curd too rapidly. ^ Fisk, W. W., A study of some factors influencing the yield and moisture content of Cheddar cheese, Cornell Exp. Sta. Bui. 334, 1913. CURD-MAKING 69 Causes of insufficient moisture: Cutting the curd too fine or breaking up the pieces with the rake into too small pieces. Cutting the curd too soft. Stirring the curd too much by hand as the last of the whey is being removed. Developing high acid in the curd at the time of removing the whey. Insufficient piling of the curd during the cheddaring process. Using a large amount of salt. High temperature and low humidity in the curing room. 92. Relation of moisture to manufacture and quality. — (1) Flavor: If the cheese contains too much moisture, it is likely to develop a sour or acidy flavor. A cheese with a normally high moisture-content usually ripens or develops a cheese flavor much faster than one with a lower moisture-content, other conditions being uniform. A cheese with a high moisture-content is much more liable, during the curing process, to develop undesirable flavors than is one with a lower moisture-content. (2) Body and texture: A cheese containing too much mois- ture is very soft and is difficult to hold in shape. Such a product breaks down very rapidly and is usually pasty and sticky in texture. If too little moisture is present, the cheese is very dry and hard, and cures or ripens very slowly because of the lack of moisture together with milk- sugar from which acid may be formed. Dry cheeses are usually harsh, tough and rubbery in texture. Such cheeses also have poor rinds. (3) Color: If the ideal conditions exist, the moisture will be evenly distributed throughout the cheese. The spots containing more 70 THE BOOK OF CHEESE moisture will be lighter in color. If a cheese con- tains so much moisture that it becomes " acidy," the effect is the same as when too much acid is developed, that is, the color becomes pale from the action of the acid. (4) Finish: A cheese containing too much moisture is usually soft. A good rind does not form. Such a cheese loses its shape very easily, especially in a warm curing room. (5) (Quality: A cheese with a high mois- ture-content is usually marketable for only a very short period. Such a product usually develops flavor very quickly in comparison to a dry cheese. It must be sold very soon because if held too long, the flavor be- comes so strong as to be undesirable, and objectionable flavors are liable to develop. In some cases, such cheeses rot. 93. Relation of moisture to acidity. — From the pre- ceding discussion, it is evident that the relation between the moisture and acidity is very close, in fact so intimate that in some cases it is difficult to distinguish one from the other when the quality of the cheese is considered. The proper relation of the moisture and the acidity de- termines the quality of the resulting cheese. If too much acid is developed during the manufacturing process, the product will be sour. If too much moisture is retained in the form of whey, the cheese will be s'our. The less acid in the curd, the more moisture in the form of whey may be retained in the curd without causing a sour cheese. The proper relationship between the mois- ture and the acidity must be maintained or a sour cheese will result. The relation of the moisture to the acidity also has an influence on the curing. If the cheese has a low develop- ment of aciditv and a low moisture-content, it will cure CURD-MAKING 71 very slowly. The increasing of either the acidity or moisture usually increases the rate of cheese ripening, other factors being the same. The relation of the acidity and the moisture is so im- portant that it cannot be neglected without injuring both the quality and quantity of cheese. This knowl- edge can be obtained only by experience. 94. Setting temperature. — The temperature of ren- neting makes very much difference in the texture of the product. The enzyme rennin is sensitive to very slight changes in temperature. Below 70° F., its rate of action is very slow. Beginning with approximately 20 per cent of its maximum effectiveness at 70° F. (the curdling point for Neufchatel), it has risen to 65 per cent at 84° F., to 70 per cent at 86° F., as used in Cheddar, to about 80 to 85 per cent at 90-94° F., as used in Lim- burger. At 105° F. it reaches its maximum effectiA-e working rate to fall from that efficiency to about 50 per cent at 120° F. Curdling at low temperature lengthens the time required for the same amount of ren- net to curdle a given quantity of the same milk. The texture of ciu-d produced at temperatures between 70° F. and 84° F. is soft, jelly-like, friable rather than rubbery. At 86° F. it begins to show toughening or rubbery char- acters which become very marked at 90° F. to 94° F, as used in Limburger. With the increased vigor of action as it passes its maximum rate of action at 105° F., the texture tends to become loose, floccose to granular. Aside from the Neufchatel group, the work- ing range of temperatures for the renneting period runs from about 84° F. to about 94° F., a range of barely 10° F., or the use of 65 per cent to 80 or pos- sibly 85 per cent of the maximum efficiency of the 72 THE BOOK OF CHEESE rennet. Within this range of temperature, the curd has the physical characters demanded for making most vari- eties of cheese. 95. Strength of coagulating materials. — Rennet and pepsin preparations vary in strength and in keeping quality. With a particular stock, changes go on to such a degree that the last samples from a barrel of rennet are much weaker than the earlier ones. Each sample, barrel, keg or bottle should be tested before used. In continuous work the results of each day's work furnish the guide for the next day's use of a particular lot of rennet. 96. Amount of coagulating materials to use. — For most varieties of cheese, sufficient rennet extract or pepsin is added to the milk to give a firm curd in twenty- five to forty minutes. Of the ordinary commercial rennet extract, this requires from two and one-half to four ounces to one thousand pounds of milk. This gives a maximum of one part rennet for each four to six thousand parts of milk. The great strength of the rennet extract is thus clearly shown. 97. Method of adding rennet. — Before rennet is added to the milk, it is diluted in about forty times its volume of cold water, which chills the enzyme and retards its action until it can be thoroughly mixed with the milk. If the material is added without such dilution, the concentrated extract produces instant coagulation in the drops with which it comes in contact, forming solid masses from which the enzyme escapes only slowly to diffuse throughout the mass. Uniform coagulation thus becomes impossible. After the rennet extract has been diluted w^ith cold water, it should be distributed the entire length of the vat in an even stream from a pail. It should then be mixed with the milk by stirring from CURD-MAKING 73 top to bottom for about three to four minutes. For this purpose, either a long-handled dipper or a wooden rake may be used. A dipperful should be drawn from the gate and stirred into the vat, otherwise the milk in the gate will fail to coagulate properly because the rennet diffuses too slowly to reach and affect all the milk at that point. The milk should be stirred on the top, preferably with the bottom of a dipper, until signs of coagulation begin to appear. This stirring keeps the cream from rising. There are various ways or signs to indicate when the coagulation has gone to the stage at which the mix is about to become thick : (1) The milk becomes lazy or thicker as the finger is passed through it; (2) bubbles caused by moving the finger remain on the milk longer, usually until one can count ten when ready to thicken. If the milk is stirred too long or after it begins to thicken, the result is a granular sort of curd, and there will be an abnormally large loss of fat in the manufacturing process. The addition of the rennet and subsequent stirring re- quire the exercise of great care and constant attention to details. The cheese-maker can do nothing else for those few minutes. When through stirring, it is a good plan in cold weather to cover the vat with a cloth as this will keep the surface of the curd warm. In summer the same cover will keep out the flies. Causes of a delayed coagidation : (1) Weak rennet extract or too small an amount. (2) Low temperatures due to inaccurate thermometers. (3) Pasteurized milk. (4) Presence of abnormal bacterial ferments. (5) Presence of preservatives. 74: THE BOOK OF CHEESE (6) Heavily watered milk. (7) Use of badly rusted ^ cans. (8) IVIilk containing small amounts of casein or cal- cium salts. Causes of uneven coagulation: (1) Uneven temperature of the mix in the vat, due to lack of agitation. (2) Uneven distribution of the rennet extract. (3) Adding rennet to vat too soon after heating, while the sides and bottom are still hot, causes curd to stick to sides and bottom of the vat making cutting difficult. (4) Sloshing after the milk begins to thicken breaks the curd and causes it to whey off. 98. The curdling period. — The time allowed for rennet action also afi'ects the texture of the curd. The enzymes of rennet (rennin and pepsin) do not cease acting with the thickening of the milk. In many cheeses, the handling process begins as soon as the curd has become solid enough to split cleanly before a finger thrust into it. If let stand further, the same curd mass will con- tinue to harden with the progressive separation of whey; this shows first as drops (" sweating ") on its surface, which then increase in number and size until they run together and form a sheet of whey. The limit of such action is difl&cult to measure. The solidifying process ceases in a period of hours. The further action of the enzymes is digestive in character and goes on slowly. It requires a period of weeks or even months to accomplish measurable results at the working temperatures in use in the trade. Other ripening agents with more rapid ^ Olson, G. A., Rusty cans and their effect upon milk for cheese-making, Wis. Exp. Sta. Bui. 162, pages 1-12, 1908. CURD-MAKING 75 action intervene to shape the final result. It follows that the rennet factor in the ripening changes found at the end of the period is almost negligible for most varieties of cheese, although it appears to be measurable in some varieties. 99. Cutting or breaking ^ the curd. — As soon as curd is formed, separation of whey begins upon the surface and perhaps around the sides of the vessel. This is accompanied by shrinkage and hardening of the mass. If the curd remains unbroken, the separation is extremely slow. In cheese-making practice, such curd masses may be dipped at once into hoops as in Camembert, dumped in mass into cloths for drainage as in Neufchatel or, as in the larger number of cheeses, cut or broken in some characteristic manner. After the curd mass is firm, the rate at which subsequent changes take place depends largely on the size of the particles into which the curd is cut. The smaller the particles, the quicker the water is expelled. Consequently the development of the acidity and other changes take place more slowdy. For this reason the curd should be cut into pieces of uniform size. If the work is not properly performed, the pieces of curd of various sizes will be at different stages of development. The fine particles will be firm and elastic while the larger particles are still soft and full of whey and may be de- veloping too much acid. The knives should be inserted into the curd obliquely so that they will cut their way 1 The term " broken " is included here because the use of some curd-breaking tool has always formed a step in certain com- mercially successful processes. In every case in which careful experimental work has been done the curd knife has been suc- cessfully substituted for the breaking tool and has reduced the losses of fat and casein and in addition aided in obtaining more uniform cheese. 76 THE BOOK OF CHEESE into the curd and not break it. The horizontal knife is used lengthwise of the vat and cuts the curd into layers of uniform thickness. The perpendicular knife then is used lengthwise and crossw^ise of the vat. It first cuts the curd into strips and then into cubes. The knives may have wire blades or steel blades, some operators preferring one and some the other. Whichever is used, the blades should be close enough together to give the fineness of curd desired. After the knife passes through, the cut faces quickly become covered with a smooth coating, continuous over all exposed areas. This surface has the ap- pearance of a smooth elastic coating or film. This can be seen by carefully breaking a piece in the hand. It is this film which holds the fat within the pieces of curd. If the film is broken, some of the fat globules are lost because the rennet extract acts only on the casein and that in turn holds the fat. All the fat globules which come in contact with the knives as they pass through the curd will be left between the pieces of curd and will pass off in the w^hey. If care is exercised in cutting, the loss of fat will be confined to what may be called a mechanical loss. This is similar to the loss of the sawdust when sawing a board. This loss in American Cheddar is about 0.3 per cent and cannot be avoided. If it is greater than this, it is due to negligence on the part of the cheese-maker or the poor condition of the milk. The cutting of the curd into small pieces may be considered a necessary evil. If the moisture could be expelled from the whole mass without disturbing it, this fat loss could be prevented. The cutting, breaking or turning should be done wath the greatest care, that the loss may be as small as possible. CURD-MAKING 77 100. Curd knives. — For cutting curd, special knives have been devised (Fig. 11). They consist of series of parallel blades fixed in a frame to make cuts equidistant. The blades run \'ertically in one, horizontally in another. Horizontal Perpendicular Horizontal Perpendicular Fig. 11. — Blade and wire furd knives. They are spaced according to the demands of the variety of cheese to be made. Wires stretched in a frame take the place of blades in some makes of curd knife. 101. Heating or "cooking." — Curdling by rennet has already been shown to be markedly hastened by moderate heating. After the coagulum or curd is formed, the making process may be completed without the application of further heat, as in Neufchatel, Camembert and related forms (Fig. 12) and in some practices with Limburger. In other forms and especially in the hard cheeses in which cutting of curd is a prominent 78 THE BOOK OF CHEESE part of the process, the curd after being cut is reheated cooked." The cooking process hastens the removal or of the whey, thus shortening the time required to reduce Fig. 12. 2545 ■ The heat relation. See pages 77 and 87. the water-content of the mass to the percentage most favorable for the type of cheese desired. The process also produces marked changes in the physical character CURD-MAKING 79 of the curd mass. With the rise in temperature the casein becomes elastic first, then approaches a melting condition and assumes a tough, almost rubbery consistency. The final texture is the result of the combination of the amount of rennet added, the temperature, the acidity reached during the process, and the final water-content of the mass. 102. Draining (including grinding, putting into hoops or forms and pressing) . — The reduction of the water in the curd begins almost as soon as the curd becomes firm. It is aided by cutting or breaking, by the retention of the heat applied before renneting and by the second- ary heating or cooking used in making certain groups of cheeses. In many varieties special apparatus is provided in the form of draining boards, draining racks or bags to hasten the removal of the whey as fast as it separates. The draining process continues until the cheese has reached its final form and weight. The intervening process of matting in the Cheddar group involves a com- bination of a souring process with the removal of whey, during which the cubes of curd become fused into semi- solid masses. If such masses are formed, they must be ground up before the cheese can be gi\'en its final form in the hoop. The draining process, therefore, may take any one of many forms varying from the direct transfer of freshly formed curd into hoops in which the entire draining process is completed, to an elaborate series of operations which end in pressing curd drained to approxi- mately its final condition before it is placed in the hoop. 103. Application to cheese. — From the discussion of these factors, it is evident that the cheeses produced will dift'er widely with the differences in manipulation. If one considers essential constituent substances separately, 80 THE BOOK OF CHEESE the water-content of the finished product is found to vary from 30 per cent in Parmesan to 75 per cent in cottage cheese. The fat-content runs from a trace in some varieties to 60 per cent in some cream cheeses. The texture of the casein, which gives character to the product, varies from the tough or gkie-like consistency of freshly made Swiss to the buttery condition of a cream or Neufchatel cheese. Inside such Hmits the tastes of different peoples have led to the manufacture of many kinds of cheese. Each of these varieties represents some particular combination of curd-making factors and ripening conditions which produces a cheese suited to the taste of the maker and consumer of that country or community. CHAPTER VI CLASSIFICATION The literature of cheese-making contains reference to more than 500 names for varieties of cheese. Many of these can be thrown readily into great groups or fam- ilies in which there are variations in unessential detail without modifying the characteristic texture and flavor of the product. Many ^'arietal names are attached to the product of single factories or factory groups. Such varieties frequently differ only slightly in size or shape, or in stage of drainage or of ripening, from widely known varieties or other similar local forms. The descriptions recorded for such varieties commonly emphasize minor differences in manipulation without showing differences in essential factors. Vessels of particular size are pre- scribed to be made of wood, earthenware, or of a special metal. These details specify the exact size and shape of hoops, the use of particular styles of cutting or breaking instruments and of certain stirring tools, the material and construction of mats and draining racks. The descriptions themselves are very commonly in- adequate. The variable factors in cheese-making are fat-content of the milk, acidity, temperature of setting, amount of rennet, time allowed for curdling and the method of draining the curd. The differences in practice lie, with few exceptions, in the amount or intensity of particular factors, not differences in kind or quality of G 81 82 THE BOOK OF CHEESE treatment. ' Such contrasts are quantitative, not qualita- tive. A great number of combinations is possible by small variations of these factors. Varieties selected as types of groups give marked con- trasts in character, but comparison of large numbers of forms shows that almost every gradation from group to group can actually be found. Within groups frequently the same physical results in texture and flavor can be obtained by combinations or adjustments of factors for the purpose of offsetting or counteracting the effects of one change in practice by the manipulation of other factors. In ripening, an equally large range of practices makes possible the development of very different qual- ities in mature cheeses from the same lot. Only a few of the large number of described varieties have obtained even national importance ; fewer still are known outside the country of origin. In spite of the success of special products when properly advertised, the largest place in the market is clearly accorded to the standard forms which are widely known. 104. Basis of classification. — A series of these widely known forms has been chosen as typical of groups in a system of classification adapted from the French of Pouriau. No completely satisfactory scheme of classifying all of these varieties has been devised. The grouping proposed here is based on the principles of curd-making already discussed together with consideration of the ripening processes to be discussed with each group. The factors that actually influence the quality of the final product are separated as completely as possible from non-essential operative details. The common use of the terms " soft " and " hard " cheese is based on the single arbitrary fact of texture. The term " semi-hard " cheese may be conveniently CLASSIFICATION 83 applied to a miscellaneous group of unrelated families which are intermediate in texture between such soft forms as Neufchatel or Camembert and really hard cheeses like Cheddar or Parmesan. Although these terms are not made the main basis of the proposed grouping, their application to sections is indicated. Classification based on the essential facts of manufac- ture is, however, really helpful. Analytical Tabulation of Groups Section. I. Cheeses with sour milk flavor only (Eaten fresh). (Soft cheeses 45 to 75% water) Page 1. Curdled by souring, Cottage cheese and its allies in America, many related varieties in Europe 90 2. Curdled by souring and rennet — the Neufchatel group 95 a. Skim — Skim-milk NeufchS.tel . . . 105 b. Part skim to whole milk — American or Domestic Neufchatel 106 c. With fat added — the cream cheeses of the NeufchS,tel group (both American and European) — such as Cream, Ger- vais, Malakoffs, etc 108 Section II. Cheeses ripened. Subsection A. Soft cheeses (40 to 50% water). 1. Curdled by souring, heated, then ripened. Hand cheese, Pennsylvania pot cheese, Harz, etc 112 2. Curdling by souring and rennet, ripened Ripened (French) Neufchgltel . . 114 3. Curdled primarily by rennet. ■ a. Ripened by mold — Camembert, Brie and their allies . . . 117 6. Ripened by bacteria. * Made from soft or friable curd — d'Isigny, Liederkranz, etc. 134 ** Made from firm or tough curds — Limburger and allies . . 139 84 THE BOOK OF CHEESE Subsection B. Semi-hard cheeses, firm, well-drained (38 to 45% water). Page a. Curd not cooked, ripened by molds. * Made from friable curd — Roquefort 150 ** Made from firm or tough curd — Gorgonzola, Stilton and such French forms as Gex, Septmoncel 158 b. Curd cooked and ripened by bac- teria, — brick, Munster, Port du Salut (Oka) 164 Subsection C. Hard cheeses, cooked and pressed (30 to 40% water). a. Ripened without gas holes. 1. Dutch — Edam, Gouda ... 173 2. Danish. 3. The Cheddar group. * English — Cheddar and numer- ous related forms known principally in Great Britain 184 ** American — the factory Ched- dar of United States and Canada 184 b. Ripened with the development of gas holes. * Holes large — Swiss-Emmen- thal, Gruyere, American S^\dss 276 ** Holes small — ^ Parmesan and related varieties .... 288 Such a classification brings together series of products in which there is essential similarity in the final output, however great the differences in manipulation. It does not consider all varieties and specialties. Some of these groups are important enough to demand special mention. 105. Processed cheeses. — Cheese of any group may be run through mixing and molding machines and re- packaged in very different form from that characteristic of the variety. In such treatment, the texture and CLASSIFICATION ^ 85 appearance may be so changed as to give the effect of a new product. Substances (such as pimiento) are added to change the flavor. Or the product may be canned and steriUzed with equally great change of flavor and tex- ture. One thus finds Club made from Cheddar; Pimi- ento from Cream, Neufchatel or Cheddar ; similarly olive, nut and other combinations are made. The possible variations are numerous. 106. Whey cheeses. — Several products bearing cheese names are made from whey. These take the forms of the recovery of the albumin and casein separately or in a single product, and the recovery of the milk-sugar either alone or with the albumin. Whey cheeses have been especially developed by the Scandinavian people, although some of them have their origin in the south of Europe. Certain of these varieties are produced on a limited scale in America. There are a number of forms fairly widely known that are difficult to place in this scheme of groups. Among these are Caciocavallo, Sap Sago. 107. Soft and hard cheeses. — Another commonly used classification makes two groups : (1) soft cheeses ;'' (2) hard cheeses. In such a classification the semi-hard group presented here is included with the soft cheeses. Some cheeses of this group are soft in texture. This is correlated with high water-content, high fat-content or both together. 108. Relation of moisture to classes. — In this classi- fication the water-content reflected in the texture of the cheese assumes first place. To carry the analysis some- what further by showing the correlation between water- content and certain factors, a tabulation of well-known varieties of typical groups is presented (Table III). In 86 THE BOOK OF CHEESE this table the series of typical dairy products are first arranged according to water-content of the final product. Approximate limits of percentages of milk-fat are also given, because milk-fat frequently affects texture to a degree almost equal to water. Column 4 gives the period within which the more quickly perishable cheeses are usable, and the length of the ripening for the more solid forms. The correlation between water-content, texture and the time of keeping is clearly shown for most varieties. TABLE III Correlation Water- and Fat-Content with Ripening Per Per Period Ripening Variety of Cent Water Cent Fat Required Agent Cheese: Soft, Cottage .... 70 trace a few days Bacteria Skim Neufchatel . 70 trace a few days Bacteria Neufchatel . . . 50-60 12-28 a few days Bacteria Camembert . 50 22-30 3-5 weeks Molds Cream cheese 40-50 35-45 a few days Primarily bacteria Semi-hard : Limburger . . . 40-45 24-30 3-6 months Bacteria Roquefort . . . 38-40 31-34 3-6 months Mold Brick 37-42 31-35 3-6 months Bacteria Hard: Cheddar .... 30-39 32-36 6-12 months Bacteria Swiss 31-34 28-31 9-18 months Bacteria and yeasts Parmesan . . . 30-33 2-3 years Bacteria The soft cheeses are quickly perishable products. Bacteria and molds find favorable conditions for growth CLASSIFICATION 87 in products with 45 to 75 per cent of water. If such growth is permitted, enzymic activities follow quickly with resultant changes in appearance, texture, odor and taste. Refrigeration is necessary to transport such cheeses to the consumer, if properly ripened. Trade in these forms may continue throughout the year in cool climates and in places where adequate refrigeration is available. Practically, however, outside the large cities this trade in America is at present limited to the cold months ; inside the large cities much reduced quantities of these cheeses continue to be handled through the year. In the stricter sense, the soft group of cheeses falls naturally into two series: (1) the varieties eaten fresh; and (2) the ripened soft cheeses. Those eaten fresh have a making process which commonly involves the develop- ment of a lactic acid flavor by souring, but no ripening is contemplated after the product leaves the maker's hands. In the ripened series, after the making process is completed, the essential flavors and textures are de- veloped by the activity of micro-organisms during ripen- ing periods varying in length but fairly well-defined for each variety. In contrast to the soft cheeses, the hard kinds are low in water-content, ripen more slowly and may be kept through much longer periods. They retain their form through a wider range of climatic conditions. They develop flavor slowly and correspondingly deteriorate much more slowly. Such cheeses are in marketable con- dition over longer periods. In their manufacture the cooking of the curd takes a prominent place. 109. Relation of heat to classes. — The close relation between the heat applied and the product sought forms the basis of a striking series of graphs (Fig. 12, page 78). 88 THE BOOK OF CHEESE These show the changes hour by hour in the heat relation during the making process of a series of widely known forms, each of which is chosen as typical. In. some of these forms, heat is applied but once to bring the milk to the renneting temperature typical for the variety. Subsequent manipulations are accompanied by a steady fall in temperature. In other forms, the curd when solid is specially heated or " cooked " to bring about the changes characteristic of the variety. These con- trasts are clearly brought out by the graphs which rep- resent practices well recognized for the varieties. The detailed process for these groups is considered in suc- ceeding chapters. CHAPTER VII CHEESES WITH SOUR-MILK FLAVOR The cheeses with flavor of sour milk are probably more widely used than any other group. Historically and to a very large degree at present, they are farm cheeses.^ No estimate of volume of such production in the house- hold has ever been made. The utilization of surplus milk in this way is of ancient origin. With the introduction of the factory system of han- dling milk, the manufacture of such cheese in the house- hold was largely dropped. The rise in price of all food substances and increasing appreciation of the food value of milk products have made the recovery of all surplus milk in some form very necessary. The manufacture of cottage, Neufchatel and cream cheese is fene of the best forms of such recovery which may be adapted to utilize any grade from skimmed-milk to cream. Large quantities of skimmed-milk have frequently been lost from the total of human food by the manufacture of casein for industrial uses, and by use as stock feed. 110. Skim series. — The kinds of cheeses eaten fresh have in common a very soft texture and the flavor of ^ Frandsen, J. H., and T. Thorsen, Farm cheese-making, Univ. Neb. Ext. Serv. Bui. 47, pages 1-lG, 1917. Michels, J., Improved methods for maldng cottage and Neufchatel cheese, N. C. Exp. Sta. Bui. 210, pages 29-38. Fisk, W. W., Methods of making some of the soft cheeses, Cornell Exp. Sta. Circ. 30, pages 41-62, 1915. 89 90 THE BOOK OF CHEESE sour milk, principally lactic acid. The group falls natu- rally into two sections : (1) the cheeses made from milk curdled by souring ; (2) those for which the milk is curdled by souring and rennet. In the latter group both agencies are necessary to the resulting product. The time required to curdle by souring alone is longer than when rennet is used ; this period is usually longer than necessary for the cream to rise by gravity ; hence the cream is either skimmed off or removed with the separator beforehand. The curd, therefore, is essentially a skimmed-milk curd. Casein curdled in this way tends to become granular or " rough," to feel " sandy " when rubbed between the fingers. Heating is commonly necessary to lower the water-content of the mass even to 75 per cent. Such curd tends to become hard or rubbery when heat is ap- plied. In this group, the best known form is variously called " cottage " cheese, " clabber " cheese, schmier- kase. 111. Cottage cheese is made from skimmed-milk, soured by lactic bacteria until a curd is formed. This is done preferably at about 20° C. (70° F.), because at this temperature the purely lactic type of organism has been found to outgrow competing forms which may be present. Starter containing the desired culture, if prop- erly used, saves much time in the curdling period. Such curdling requires at least twelve to twenty-four hours, frequently much longer unless abundant starter is intro- duced. 112. Household practice. — The details of cottage cheese making in the home differ widely in separate sec- tions and even in different families in the same part of the country. The essentials of the practice, common to all, include : (1) curdling the whole milk by natural CHEESES WITH SOUR- MILK FLAVOR 91 souring; (2) removing the sour cream which is usually used for butter-making ; (3) scalding the curdled skimmed- milk either by slowly heating it in the original vessel surrounded by hot water or by actually pouring an approximately equal volume of boiling water into the curdled mass ; (4) bagging and draining the mass until it reaches the desired texture; (5) the kneading of the mass with the addition of salt and cream. The result- ing product varies greatly in quality. Unfavorable fer- mentations frequently affect the flavor.^ The " scalding " varies from a temperature of 90° F. almost to boiling with a resultant texture varying from almost the smooth buttery consistency of Xeufchatel to hard coarse granular lumps. The best practice, using clean well-cared-for milk and draining at low temperature, produces a very attractive cheese. Such cheese is heated to 90° to 100° F. on the maker's judgment, drained carefull}^ kneaded well by hand or by machine with the addition of cream to give it an attractive texture and flavor. 113. Factory practice. — When cottage cheese is made in the factory,^ separated milk is taken ; it should be pasteurized and then soured by a lactic starter. The souring can be accelerated by the use of a starter, which may be added at the rate of 0.5 to 5 per cent of the skimmed-milk used, depending on the amount of starter that can be made. Generally, the more starter added, the more rapid will be the coagulation and the better will be the flavor of the cheese. As soon as the milk has thickened, the curd is ready to be broken up and ^ Tolstrup, R. M., Cheese that farmers should make, Iowa Agr. 15 (1914), 2, pages 89-90. 2 Van Slyke, L. L., and Hart, E. B., Chemical changes in the souring of milk and their relations to cottage cheese, N. Y. (Geneva) Exp. Sta. Bui. 245, pages 1-36, 1904. 92 THE BOOK OF CHEESE separated from the whey. This separation is hastened by the apphcation of heat. Usually the temperature of the curd is raised slightly before it is broken up ; since this makes the curd firmer, there will be a smaller loss of curd particles in the whey. The curd may be cut with coarse Cheddar cheese knives or broken with a rake. The temperature of the curd should be raised very slowly, at least thirty minutes being taken to reach the desired final temperature. No set rule can be given as to the exact temperature to which the curd should be heated. The temperature should be raised until a point is reached at which the curd, when pressed between the thumb and the fingers, will stick together and not go back to the milky state. This temperature is usually from 94° to 100° F., but the cheese-maker must use his own judgment in this respect. If the curd is heated too much, it will be hard and dry; on the other hand, if it is not heated sufficiently, the whey will not separate from the curd and the latter will be very soft and mushy. When the curd has been heated sufficiently and has become firmed in the whey, it should be removed from the whey. This may be done either by letting down one end of the ^•at and piling the curd in the upper end, or by dipping out the curd into a cloth bag and allowing the whey to drain, which it does very rapidly. No treatment can prevent the " roughness " of an acid curd (this is a fine gritty feeling when rubbed between the fingers), but the coarse hard grainy texture and lumps charac- teristic of the highly heated curd do not develop. Experimental workers have agreed that to have the proper texture, such curd should contain when finished about 70 to 75 per cent of water. It should have a mild but clean acid flavor. Such a cheese will carry about 1 CHEESES WITH SOUR- MILK FLAVOR 93 to 2 per cent of salt, without an objectionably salty taste. This cheese is commonly sold by measure, some- times in molds or cartons. The manufacture of all forms of cottage cheese has been largely superseded by the making of skimmed-milk Neufchatel or Baker's cheese. The yield from one hundred pounds of skimmed-milk runs up to fourteen to nineteen pounds of cheese, when made very wet or from pasteurized milk. The yield varies with the moisture-content of the cheese, being greater for cheese with a high content. Too much moisture or whey should not be left in the curd, how- ever, as this will render it too soft to be handled. Cottage cheese made by either the home or factory practice is a quickly perishable article. Although the acid restrains bacteria at first, the high percentage of water favors the growth of molds which tolerate acidity, especially Oidium (Oospora) lactis and the Mucors or black molds. These molds destroy acidity rapidly and thus permit the bacteria of decay to develop and to produce objectionable taste and odors. Spoilage in these products is accelerated by the kneading process which distributes air throughout the mass and with it all forms of microbial contamination. 114. Buttermilk cheese. — A cheese closely resembling cottage may be made from buttermilk. If the buttermilk came from cream which was churned before it became sour, the process is the same as that already described for the making of cottage cheese from skimmed-milk. If the buttermilk came from sour cream the process of manufacture is much more difficult. The casein of sour cream has already been coagulated with acid and broken during churning into very minute rather hard particles. These fine particles are difficult to recover. They are so 94 THE BOOK OF CHEESE fine that they pass through the draining cloth or at other times clog it and prevent drainage. They do not stick together at ordinary temperatures. They cannot be collected by the use of acid because they have already been coagulated with acid. After casein has been coagulated with acid, rennet extract will not recoagu- late the particles. The buttermilk may be mixed with sweet skimmed-milk ; then as the latter coagulates, it locks in the casein of the buttermilk so that it can be collected. If buttermilk from soured cream is used alone, the casein may be collected^ by neutralizing and heating to 130 to 150° F., and holding until the casein gathers together. The whey can then be drawn ott'. Often there is further difficulty in getting the casein to collect, since the pieces remain so small that they go through the strainer. Cheese made entirely from buttermilk is sandy in texture and often not palatable. If the buttermilk with good fla\or is mixed with skimmed-milk, it makes a good cheese closely resembling cottage. 115. Neufchatel group. "^ — The Neufchatel process originated in northern France where a number of varieties are included under this as a group name. Among these are Bondon, INIalakoft', Petit Suisse, Petit Carre. The name designates a general process of curd-making which is applied to skimmed-milk, whole milk or cream. Some of the resultant cheeses are ripened ; some are eaten fresh. The Neufchatel cheeses of France gained such wide recog- nition for quality that the process of making has become widely known. In America the manipulations of the ^ Sammis, J. L., Three creamery methods for making butter- milk cheese. Wis. Exp. Sta. Bui. 239, 1914. - Matheson, K. J., C. Thom and J. N. Currie, Cheeses of the Neufchatel group. Conn. (Storrs) Exp. Sta. Bui. 78, pages 313-329, 1914. CHEESES WITH SOUR-MILK FLAVOR 95 French process were early dropped. The essentials were made the basis of a successful factory practice which has been widely adopted. The American factory prac- tice is discussed here and the French process briefly considered under the heading Ripened Neufchatel. (See Chapter VIII.) 116. Domestic or American Neufchatel cheeses are soft, have clean sour milk (lactic acid) flavor and are quickly perishable. In all but the coldest weather, they require refrigeration to reduce deterioration and loss. They range in fat-content from traces only to 50 per cent and more ; in water from 40 to 75 per cent, accord- ing to the milk used. In texture Neufchatel is smooth, free from gas, free from lumps or roughness when rubbed between the fingers. This flavor and texture is obtained by a combination of slow rennet curdling with develop- ing acidity. No further ripening is permitted. 117. The factory. — Neufchatel factories require the standard dairy equipment for receiving, weighing, testing, separating, heating, pasteurizing and cooling the milk. Since many factories produce several products, the same general dairy equipment may serve for all. In addition to such equipment, Neufchatel requires a cur- dling apparatus which can be held at 70-75° F. This may be a room properly controlled, or a tank where tem- perature control is obtained by water and steam. For draining, a room kept at 60° F. gives nearly the ideal temperature, which must be supplemented by relative humidity high enough to prevent the exposed surface of curd from drying during periods of twelve to twenty-four hours. This requires almost a saturated atmosphere. A room with special molding machinery is required and tables for wrapping, labeling and boxing the product 96 THE BOOK OF CHEESE CHEESES WITH SOUR-MILK FLAVOR 97 are necessary. Box-making machinery is usually an economic necessity for work on a large scale. Adequate refrigeration is requisite both to chill the curd before molding and to preserve it after packaging. 118. Cans. — For curdling, the " shot-gun " can, about nine inches in diameter and twenty inches deep, is gen- erally used. This holds thirty to forty pounds of milk. Increased capacity is dependent, therefore, on the number of units installed, not on changes in the units themselves. 119. Draining racks. — A draining rack is required for each can of curd. These racks also are standardized units whose num- ber limits the capacity of the factory. The de- sign of these racks (Figs. 13, 14) and their ar- rangement in the draining room are taken from Bul- letin 78 of the Storrs Agricul- tural Experiment Station : " The racks are rectangular, thirteen inches wide, thirty-six inches long and ten inches deep. The corner posts extend one and one-half inches beyond the strips at top and bottom with the tops rounded as a rule as seen in the photograph. The bottom slats fit loosely into notches, hence are removable for washing purposes. The materials required are four corner posts one and one-half by one and one-half inches ; nine strips one by three-eighths by thirty-six inches ; six strips one by three- FiG. 14. — Detail of a Neufchatel draining rack. 98 THE BOOK OF CHEESE eighths by thirteen inches, two strips one by three-eighths by twelve and a quarter inches, notched to receive the bottom slats ; all made from pine." 120. Cloths. — For each draining rack, a cloth one yard wide and one and one-half yards long is required. Cotton sheeting is satisfactory for the purpose ; " even- count, round-thread, unmercerized voile " is suggested by Dahlberg.^ 121. Molding machinery. — For work on a large scale, special power machines ^ are regularly used. These consist of a hopper and worm delivering a standard size stream of curd through a proper size and shape of delivery tube. This curd stream is cut by an automatic device into the proper lengths to form the standard cheese. In this way a uniform size of cheeses is obtained. Experi- mental work with hand apparatus showed that a worm six inches in diameter is required to deliver curd in a smooth column one and one-half inches square. If the pressure is not sufficient, ^ Dahlberg, A. O., The manufacture of cottage cheese in creameries and milk plants, U. S. Dept. Agr. Bui. 576, pages 1-16, 1917. 2 Since the number of factories has continued small, the manu- facture of this type of machine has remained a monopoly in which each machine is made to order by the Van Eyck Machine Co. of Holland, Mich. Fig. 15. — Neuf chatel and cream cheese molds. CHEESES WITH SOUR- MILK FLAVOR 99 the column will frill at the edges. Such irregular surfaces cannot be wrapped smoothly enough to delay spoilage. On a small scale, a fair grade of product can be molded through a tin tube (see Fig. 15) one and three-quarters inches in diameter and ten inches long in which the curd is compressed by a close fitting plunger operated by hand. 122. Milk for Neufchatel should be clean, free from gas and taint. Such milk should preferably be not more than twelve hours old when received and in no case show higher than 0.20 per cent lactic acid by titration. Milk testing 4 per cent fat or higher will produce a higher qual- ity of product than lower grade milk, although every grade from skimmed-milk to cream is used in producing some form of Neufchatel. This milk should be pasteur- ized unless shown to be free from tuberculosis by proper test of the cattle. Evidence ^ that the organism of tuber- culosis will withstand the regular handling process for cheeses of this group and retain its ability to cause dis- ease in experimental animals makes the introduction of pasteurization necessary in this whole group of cheeses. Any effective pasteurization may be used, but tempera- tures of 140-145° F. for thirty minutes have been effective with less changes in the milk than higher tem- peratures for shorter periods. The milk should be cooled to curdling temperature and the starter and rennet added and stirred into the milk in bulk. The milk may then be quickly distributed into the curdling cans with a hose or from the gate valve of the mixing vat. 123. Starter. — To insure the development of a clean acid flavor, a small amount of lactic starter should be 1 Presented by Dr. E. C. Schroeder of the U. S. Dept. Agr. to the International Association of Dairy and Milk Inspectors, at Washington, Oct. 17, 1917, pubUshed Jour. Am. Vet. Med. Assoc'n 52, N. S. 5, no. 6, pages 674-685, 1918. 100 THE BOOK OF CHEESE used. The quantity to use depends on the quaHty of the milk. With skimmed-milk, a pint for each thirty-pound can is recommended by Matheson and Cammack ^ and by Dahlberg. (See page 98.) For whole-milk Neufchatel, 2 c.c. to a thirty-pound can of milk commonly gives good results. On this basis 2 ounces of starter would be suf- ficient if properly stirred into about 1000 pounds of milk. Too slow development of acid is preferable to over-rapid souring. 124. Renneting or setting. — The milk should be cooled after pasteurizing to between 70° and 75° F. Ren- net is added at the rate of ^ c.c. to a thirty-pound can (roughly ^ ounce to 1000 pounds). This will thicken the milk sufficiently in the first few hours to reduce the separation of the cream. For completion of the curdling and souring process, twelve to eighteen hours are required. Usually the cans stand overnight at uniform temperature. When ready to drain, the curd should be firm, smooth and mildly acid. Whey separating from it should not titrate above 0.35 per cent titrated as lactic acid. 125. Draining. — A cloth is spread over a draining rack and the contents of one " shot-gun " can poured upon the cloth with as little breaking as possible. In this way a large surface is exposed. The room must be kept wet to prevent the surface of the curd drying to form crusts which stop draining. A temperature of 60° F. is favorable to the maintenance of proper texture and humidity without the development of objectionable organisms, especially Oidium lactis, which tends to cover every exposed surface in such rooms. Draining may be ^ Matheson, K. J., and F. R. Cammack, How to make cottage cheese on the farm, U. S. Dept. Agr., Farmers' Bui. 850, pages 1-15, 1917. CHEESES WITH SOUR-MILK FLAVOR 101 hastened by turning the curd or changing the position of the cloth. In factory practice, the large draining surface reduces the necessity of handling the curd and reduces the loss of fat. About twelve hours are required upon the draining racks. On a small scale with a few cans of curd in the home, any form of draining rack may be used, such as a potato or berry crate, or the corners of the cloth may be brought together, tied and the mass hung up. The curd must be turned by pulling up the corners of the cloth to prevent drying at the edges and stoppage of draining from the center of the mass. Such treatment produces much more rapid drainage than the factory practice and involves proportionately more labor and larger fat losses. 126. Cooling Neufchatel. — When whey ceases to separate readily, the corners of the cloth are loosed from the rack, folded diagonally or tied, and the curd cooled on ice or in refrigerators. When thoroughly chilled the bags of curd are put into presses, where light but in- creasing pressure forces more whey out of the mass. Tests at this time should show about 0.60 per cent acid in the whey. With low-fat curd every step of the process may be hastened, but with high-fat care must be exer- cised to prevent loss of fat during pressing especially. Any pressing device permitting continuous pressure with ease of manipulation may be used. 127. Pressing. — The ideals of the maker must deter- mine the extent of pressing. A high yield is obtained by leaving whey in the curd. If immediate consumption is certain, such cheese may be satisfactory, but if the cheese is to be held some days the extra whey carrying more milk-sugar favors increased acid development. This produces very sour cheese with much more danger 102 THE BOOK OF CHEESE of other fermentations which cause objectionable flavor. Too much water favors more active bacterial growth as well as produces cheese too soft for the necessary handling in the market. In the press, several bags of curd may be piled together. The press should be released and the bags turned from time to time to insure even drainage. Several hours of pressing are usually required. The danger of insufficient pressing is due to the difference of texture between the worked and un worked curd. Before working, curd carry- ing 10 per cent excess moisture resembles the finished product sufficiently to deceive any but the experienced maker. But if this curd is transferred to the worker and to the molding machine, it is found to become soft, pasty and stickj^ to lack "body," hence to make very unsatis- factory packages and to spoil very quickly. The masses of curd should come out of the press as dry and hard flat cakes. 128. Working and salting Neufchatel. — The cakes of curd go from the press to the working table. Here they are broken by hand or by a butter- worker or kneading machine (Fig. 16). Salt at the rate of one and one- half pounds to 100 pounds of curd is added. If the Fig. 16. — Working Neufchatel. CHEESES WITH SOUR-MILK FLAVOR 103 curd is not sufficiently pressed, the masses become mushy or pasty during the working process. The work- ing is continued until the whole mass is uniformly smooth and buttery. 129. Storage. — The draining and working processes permit the contamination of the curd with organisms from the air and from the apparatus. These are dis- tributed throughout the mass. Air is also worked thoroughly into the curd. Such a product spoils quickly. Distributing houses find the Neufchatel trade uncertain in volume from day to day, hence many of them store the cheese in bulk and package only fast enough to fill orders. This minimizes the loss due to spoilage. Such curd may be packed into tubs and kept for considerable time in cold storage. If molded for the retail trade, it is more quickly perishable. When packed solidly in mass, curd is largely protected from spoilage by the ex- clusion of air and perhaps the quick exhaustion of free oxygen through the respiration of the micro-organisms present and by its acidity. This must be supplemented by low temperature to reduce the loss to a minimum. Even when spoilage begins, it is easily confined to the slight growth of Oidium lactis or green mold and bacteria on exposed areas. These can be removed with minimum loss and damage to the mass. On the other hand, such curd molded into the commercial package of 3 to 6 ounces and wrapped in paper, with tin-foil or carton for protection, still presents enormously increased surface for the growth of aerobic forms — especially Oidium lactis, green mold (Roquefort mold is the usual green species) and accompanying bacteria. Curd in tubs may be kept some days ; in commercial packages lowering of quality (flavor) begins almost at once. 104 THE BOOK OF CHEESE 130. Molding. — When the standard molding ma- chine (Fig. 17) is provided, curd is brought directly from the refrigerator to the machine. If permitted to be- come warm, the mass becomes sticky; when cold it is more readily handled. The machine is fitted with the special delivery tube for the variety to be handled, cylindrical for Neufchatel in its various forms, rectangular in section for cream. Enough workers should be pro- vided to wrap and label the cheese without leaving it Fig. 17. — Molding Neufchatel. exposed to contamination or heat. Parchment paper and tin-foil cut the proper size for each variety and bear- ing printed labels are readily obtainable. Each cheese should be wrapped with paper and tin-foil and put directly into a Hat box which holds a standard number (usually 12 or 24) of the special product. In working with the hand molding tube (Fig. 15) the same care is required. Chilled curd is forced into a firm smooth mass with the plunger. It is removed CHEESES WITH SOUR-MILK FLAVOR 105 and wrapped when it reaches the regular size of the variety. All forms when molded go directly into the boxes and then back to the refrigerators until demanded for actual use. The details of the process diflfer according to the form made. 131. Skimmed-milk Neufchatel. — Separator skimmed- milk is frequently made into curd by the Neufchatel process. The absence of fat eliminates the largest element of loss in manufacture. Each stage of the making process, therefore, may be shortened. The demand that the curd shall be smooth and buttery in texture rather than rough or gritty requires the exercise of care in curdling of milk. The draining and pressing of the curd may be accomplished much more rapidly than in the fatty cheeses. The final product should differ from cottage cheese in smoother texture, milder acidity and, as a rule, cleaner flavor. In composition, the absence of fat must be largely compen- sated by leaving more water in the cheese. Such a product reaches the market with 65 to 75 per cent of water and perhaps 1.25 per cent of salt. Casein forms 20 to 30 per cent of the mass. These cheeses are very perishable on account of their high water-content. The destructive effect of micro- organisms both in the interior of the cheese and upon its surface is rapid. Cheeses of this description may be found in the trade as cottage cheese, Neufchatel style, and as Neufchatel made from skimmed-milk ; skimmed-milk Neufchatel would be a strictly proper labeling. 132. Baker's cheese. — There is considerable market for skimmed-milk curd as Baker's cheese. This product is essentially skimmed-milk Neufchatel curd, partially 106 THE BOOK OF CHEESE drained and sold in bulk. When the bakery is near by, the curd is frequently shoveled into milk-cans in very wet condition and sent directly from the factory to the bakery. If the distance is such as to require considerable time for transportation, the same care is frequently given as for Neufchatel curd packed in bulk for storage and transportation. Great variations in practice are found among the makers of this type of product. In some cases low grade skimmed-milk is handled on a large scale. Curdling is done quickly and little care is gi\en to the details of flavor and texture in the curd. Working in this manner, two men are able to make a ton of such curd, and ship it out in milk-cans each day. The resulting product, although very deficient in flavor and texture, goes into manufac- tured specialties which conceal its deficiencies if con- sidered as cheese. 133. Domestic Neufchatel. — The name Neufchatel, unless limited clearly by the label, should designate a cheese made from fresh whole milk. Cheeses of this group are produced in a small number of well-equipped factories scattered widely through the dairy states of the North and Northeast. Every factory uses one or more trade names for its product. The same product is frequently relabeled by the distributor who uses his own trade name instead of that of the maker. The usual form of package is cylindrical, about if inches in diameter and 21 indies long, or sometimes rectangular 2| by 1| by 1^ inches. The cheese is pro- tected by wrapping in parchment paper closely surrounded by tin-foil. These packages vary from 2| to 4 ounces. In some cases screw-topped glass jars are substituted for the tin-foil package. They are objectionable, first, be- CHEESES WITH SOUR-MILK FLAVOR 107 cause of cost and, second, because they are so commonly associated with less perishable products as to mislead either dealer or consumer into holding the product for too long a time. The paper or tin-foil package can be kept only at refrigerator temperature, hence automat- ically keeps its possessor reminded of the perishable nature of its contents. Neufchatel of the best quality made from whole milk testing about 4 per cent fat may be expected to fall within the following limits ; ^ many grades contain more water than this at the expense of flavor and keeping quality : Water 50-55 per cent Fat 23-28 per cent Casein 18-21 per cent Salt 0.5-1.25 per cent Yield 12-14 lb. per 100 lb. of milk. 134. Partially skim Neufchatel. — Brands of Neuf- chatel made from milk that would test every gradation from whole milk to separator skimmed-milk may be found. The quality of the product varies with the skill of the maker from brands no better than cottage cheese to products scarcely distinguishable from the best whole- milk Neufchatel. Many factories that produce more than one quality of Neufchatel use labels of different color, different design or both to separate them ; for example, blue labels usually stand for whole milk, red labels represent lower grades. Sometimes the difference in material is indicated by a clear cut grade mark. Fre- quently color, a design of label or both are the only definite marks upon the cheese. The consumer un- familiar with the trade practice commonly has no means of knowing the quality of the product offered. Such 1 Taken from Conn. (Storrs) Exp. Sta. Bui. 78, page 328. 108 THE BOOK OF CHEESE cheeses vary in water-content from 55 to 70 per cent; in fat from 10 to 25 per cent; in casein from 18 to 25 per cent. 135. Cream cheese. — The Neiifchatel process is also used to make cream cheese. The material utilized is connnonly what has been called double cream. This is produced by separating about half of a gi^•en volume of milk and running the cream into the other half. Usually cream cheese is made in the same factory as various grades of Xeufchatel. No material is lost. In some instances, cream cheese is prepared by working thick cream into the Xeufchatel ty]x> of curd from practically skinunetl-milk. In working with high })crccntages of fat in curd, care must be taken to a\ oid loss of fat in draining and pressing. The curd is carefully chilled before press- ing to reduce this loss. This may be done under refriger- ation or upon cracked ice. Otherwise the manipulations of the process are unchanged. The cheeses are conuuonly molded in the Xeufchatel machine into square cakes weighing about 4 ounces and measuring approximately 3 by 2\ by | inches. These are wra]^])ed in paper and tin-foil and handled exactly as X'eufchatel. Cream cheese of high quality made from reenforced milk testing 7 to per cent fat may be expected to test approximately as follows : ^ Water 38-43 per cent Fat 43-48 per cent Protein 13-lG per cent Salt 0.5-1.25 per cent Yield 16-18 lb. per 100 lb. of cream. Increases of water, hence greater yields, are very com- mon but usually associated with loss in quality both as 1 Taken from Conn. (Storrs) Exp. Sta. Bui. 78, page 328. CHEESES WITH SOUR- MILK FLAVOR 109 to flavor and texture, and in more rapid spoilage; eertain brands regularly carry 50 to 60 per cent of fat hut their increased cost of manufacture and sale restricts them to the role of specialties with closely limited distribution. Trade names such as Philadelphia Cream, Cow Brand, Eagle Brand, Square Cream, Blue Label and many other factory brands are on the market. 136. Neufchatel specialties. - — Neufchatel or cream cheese curd is frequently mixed with some flavoring substance, such as pimiento (pickled Spanish peppers), olives, nuts, spices or other cheeses, such as Roquefort. These bear appropriate trade names and form a very attractive addition to our varieties of cheese. Among the names found are Pimiento, Olive, Nut, and Pim-olive or Olimento. 137. Gervais is a brand of cream cheese made in Paris and sold widely in France and even in other continental countries. It occasionally comes to America. As made in Paris, these cheeses are flat cakes containing approx- imately 40 per cent water and 35-45 per cent fat. It clearly differs only in detail from the square cream cheeses made in America. The name Gervais is the property of a particular company. Since the cheese differs in no essential feature from other cream cheeses, this name should not be applied to a domestic cream brand. 138. European forms occasionally imported. — Among the cheeses related to Neufchatel as they reach the market are the " White " cheeses of southern Europe. These differ greatly in quality according to their source and to their content of cow, sheep, goat's milk or some com- bination of these. This texture and flavor link them with unripened Neufchatel. The time required for importation puts a minimum possible period of ten to fif- 110 THE BOOK OF CHEESE teen days between production and consumption with a probable period of at least one month for most samples. As they come to America, these forms usually show fermentive changes beyond those tolerated in the do- mestic product. This may take either of sever.al forms : (1) intensification of acid flavor with the intensification of the characteristic flavors of the particular brand ; (2) the development of old or rancid flavors ; (3) the de- velopment of Oidium and partial softening of the mass through its agency ; (4) the growth of Roquefort mold and development of the flavor associated with that organism. This last form was found in a shipment of Hungarian Briuse which showed about 40 per cent fat, 14 per cent protein and 43 per cent water. CHAPTER VIII SOFT CHEESES RIPENED BY MOLD The ripened soft cheeses include a series of groups of varieties which, in addition to initial souring, have been subjected to special ripening processes, and which in the ripened condition are soft in texture and mostly have high flavors. The varieties in each group have in com- mon some essential principles of manufacture together with a ripening process dominated by a characteristic group of organisms. In certain groups, the ripening is dominated by a yellowish or orange viscid surface slime containing Oidiiim lacfis and bacteria ; in another series, the characteristic organism is a mold of the genus Pen- icillium (P. Camemherti). Referring to the analysis of groups (page 83), the ripened soft cheeses are found to fall into three well-marked groups, one of which may per- haps be subdivided as indicated. The series curdled by souring alone begins with approximately cottage cheese curd and develops high flavors by ripening, as in " hand " cheese. Ripened Neufchatel curdled by souring and rennet together finds its basis in Neufchatel curd also but modifies the final product until the familiar flavor and texture of the unripened form are no longer recogniz- able. Among the forms curdled by rennet alone the Camembert series contains one form, Coulommiers, which is opcasionally used unripe, but represents in general a mold-ripened group of highly flavored forms. The series 111 112 THE BOOK OF CHEESE of soft rennet cheeses ripened by bacteria may be broadly designated the Limburger group. 139. Hand cheese and its allies. — Among skim cheeses, there is a series of forms largely German in origin in which curd not far removed from cottage cheese is the basis of the product. Harz cheese is one of the best-known of these forms as studied by Eckles and Rahn.^ One of these forms, hand cheese,^ is manufactured on a commercial basis in farm dairies among families of German descent principally in Pennsylvania, and on a factory basis in a few places in New York, northern Illinois and Wisconsin. On the small scale, curd is made by natural souring or by use of starter, heated to expel water, cooled and molded by hand into cakes two to three inches in diameter and one-half to three-quarters inch in thickness. The freshly formed cakes are placed upon a shelf to dry. There they are turned daily until fairly firm, then packed in rolls into wooden boxes and ripened in a cool damp room. In this ripening there is a prompt development of a hea^•y viscous slime, which consists of Oidium and bacteria. Other molds forming loose cottony mycelium are brushed off if they appear. The proper consistency of this slimy covering depends on a close adjustment of water-content in the cheese with tempera- ture and relative humidity in the ripening room. If conditions are too dry, the cheeses harden quickly or if less dry they are attacked by green or blue-green molds. If too wet, the slimy covering becomes too soft and watery, or secondarily covered with loose shimmering masses of 1 Eckles, C. H., and O. Rahn, Die Reifung des Harzkases, Centralb. f. Bakt.etc. 2 abt. 14 (1905). pages 676-680. - Monrad, J. H., Hand cheese, N. Y. Produce Rev. etc. 25 (1908), 16, page 644. SOFT CHEESES RIPENED BY MOLD 113 mold (Miicor sp.)- Ripening should proceed slowly and occupy a period of six to eight weeks. 140. Pennsylvania pot cheese. — A form of " pot " cheese is made in certain counties of Pennsylvania, prin- cipally for local use. Production of this cheese on a fac- tory basis is now being attempted. The steps in manu- facture are about as follows : ^ (1) The home-made type of cottage cheese curd is prepared, put into a crock or pot and covered carefully; (2) kept in a warm place (in kitchen usually) ; (3) stirred from time to time, until it has ripened to a semi-liquid condition. This occurs very rapidly under the attack of Oidium lactis accompanied by bacteria. Within a period of three to seven days, according to the temperature and to the water-content of the mass, the granules of curd become covered with a wrinkled gelatinous almost viscid mass of mold mycelium beneath which is a layer of semi-liquid curd with a strong characteristic odor and taste. This ripened or semi- liquid part reaches about half the total mass in four or five days at favorable temperatures. (4) The vessel is then placed in a larger vessel of water and heated over the fire w^ith constant stirring until the whole mass is melted and smooth. (5) Butter or cream, and salt or other flavor is finally added, stirred in and the liquid cheese poured into molds or jelly glasses to cool. If properly made and cooked, the resultant cheese has a soft buttery consistency with an agreeable flavor, which frequently resembles that of Camembert cheese. 1 The authors are under obligations to Mrs. E. E. Kiernan for her description of this process (in the Somerset County Leader, Jan. 10, 1908) and her letters concerning it. The statement of the process given here combines the published statement with the results of our own experiments. 114 THE BOOK OF CHEESE 141. Appetitost (Appetite cheese). — A Danish butter- milk cheese is made under this name. Sour buttermilk is heated, by some to boiling temperature but others (INIonrad ^) prefer 120° F., stirred thoroughly and allowed to settle. The whey is removed as far as possible. The semi-liquid mass is covered and set in a warm place. Fermentation becomes active. This tends to make the curd more viscous or sticky. It is then kneaded and allowed to ferment again. This process is repeated until the mass is yellowish and soft but tough or viscous. When thoroughly fermented, the mass is again heated to 120° F., and 6 per cent salt is added together with spice ; both are worked in and the cheese is formed into fancy shapes for sale. 142. Ripened Neiifchatel, French process. — Neuf- chatel as a ripened cheese is made rather widely in France but it is produced on an especially large scale in Seine- Inferieure." Some factories use whole milk, or milk with added cream, others skimmed-milk.^ The whole-milk brands of Neufchatel are those which have the widest reputation. For making this cheese, the working room is held as closely as possible at 15-16° C. (58-60° F.). The milk is strained into earthen vessels holding twenty liters. Rennet is added to the freshly drawn milk at about 30° C. (86° F.) in amount sufficient to produce coagulation in about twenty-four hours. Draining racks 1 Monrad, J. H., Appetitost, N. Y. Produce Rev. etc. 25 (1908), 16, page 644. 2 Pouriau, A. F., La Laiterie, sixieme ed. par Marcel Mon- teran, page 453, Paris, 1908. ^ Among the varietal names for Neufchatel cheese from whole milk or with added cream are Petits Bondons, Malakoffs, Carres affines. Among low fat or skim forms, Petit Suisse, Gournay. SOFT CHEESES RIPENED BY MOLD 115 of various forms are covered with cloth. The vessels of curd are dumped upon the racks. The whey separates slowly and drains off through the cloth. About twelve hours are allowed for this process. The corners of the cloth are then brought together and folded in or tied and the mass pressed to complete the drainage. The finished curd is worked or kneaded to produce a smooth and uniform texture. This process of curd-making is essen- tially the same as the American factory process of making Neufchatel. The ripening process has been entirely dropped in America. The curd is finally molded in metal forms 5 cm, (2 inches) in diameter and about 6.7 cm, (about 3 inches) high, open at both ends. These molds are filled, the freshly formed cheeses are pressed out with a plunger or piston and their surfaces smoothed with a wooden knife. After molding is completed, the cheeses are salted by sprinkling the entire surface with fine dry salt as the cheese is held in the hand. In this way each cheese re- ceives and absorbs 3 to 4 per cent salt. After salting, the cheeses are arranged upon boards and allowed to drain twenty-four hours. They are then removed to the first or drying room. The frames of the drying room (secherie) are covered with straw and the cheeses are placed care^ fully upon t"he straw to avoid contact with each other. They are turned each day to present a fresh surface to the straw during a period of two to three weeks in the drying room (secherie). Mold begins to show as white cottony mycelium after five to six days, and slowly turns to " blue " (bluish green). When the cheeses are well covered with this moldy rind, they are removed to the ripening cellar. In the ripening cellar also the cheeses stand upon straw. They are turned over every three or 116 THE BOOK OF CHEESE four days at first, then allowed to stand for a longer period. When ripe, a Xeufchatel cheese so made weighs about 125 grams. One liter of milk makes 225 grams of such cheese. The ripening of Neufchatel has never been fully studied, but a series of these cheeses were obtained by one of the authors ; cultures were made and examined.^ The salt-content in the first place was found to be so high that Oidiiim lactis was eliminated as an active factor in the ripening. The mold proved to be on some cheeses Penicillium Camemberti, the typical mold of Camembert as it is made in Normandy, on others P. Camemberti var. Rogeri, the pure white form as used under the patents of M. Georges Roger in the region of Seine-et-]\Iarne to the eastward of Paris and called by him and by INIaze P. candidum. The physical condition of the ripened curd and the flavors encountered were those associated with these two species by many hundreds of experiments during the Camembert investigation in Connecticut.'^ These facts justify the conclusion that ripened Neufchatel is first soured by lactic organisms, then so salted as to eliminate or reduce to a minimum the characteristic activities of Oidium lactis, while the proteolytic action and the physical changes are closely similar to those of Camembert which is ripened primarily by the same molds. ^ Thorn, C, J. N. Currie and K. J. Matheson, Studies relat- ing to the Roquefort and Camembert types of cheese, Conn. (Storrs) Exp. Sta. Bui. 79, page 392. 2 Full discussion of this product is found in U. S. Dept. Agr. Bur. An. Ind. Bui. 115. Camembert cheese problems in the U. S. also published as Storrs Exp. Sta. Bui. 58 with the same title. Also a supplementary paper in Bui. 79 of Storrs Exp. Sta. SOFT CHEESES RIPENED BY MOLD 117 143. The Camembert group. — The soft cheeses ripened by molds are French in origin. Their manufacture has spread into Germany, Italy and America. Of the series, the most widely known is Camembert, which w411 be described as typical for the group. Brie, Coulommiers, Robbiola and Ripened Neufchatel belong to this series. 144. Camembert cheese. — The origin of Camembert is given by French authorities as 1791 in the Commune of Camembert near Vimoutiers in Orne, France. From a very restricted production at first, Camembert-making has spread through the region from Caen in the west to Havre, Rouen and a considerable area east of Paris. In America Camembert began to be made in one factory about 1900. Several other factories followed by 1906. The difficulties and losses encountered led to the abandon- ment of these undertakings, until at the outbreak of the European war in 1914 but one factory was making Ca- membert and that only on an experimental scale. Mean- while the United States Department of Agriculture and the Storrs Experiment Station had taken up and solved, on an experimental basis, most of the problems arising in these commercial failures. A shortage of product at the outbreak of the war brought about the re-estab- lishment of a series of factories. The product as put on the market indicates that a permanent establishment of Camembert-making is entirely practicable. Camembert cheese is made from cow's milk either whole or very slightly skimmed ; the removal of about 0.5 per cent of fat has been found to be desirable if not actually necessary. 145. Description of Camembert.^ — These cheeses are made in sizes 2^ to 4| inches in diameter and I4 to 1| 1 Thorn, C, U. S. Dept. Agr. Bur. An. Ind. Circ. 145 (1909), page 339. 118 THE BOOK OF CHEESE inches in thickness. They are ripened by the agency of molds and bacteria which form a felt-like rind over their whole surface, tf to ^ of an inch in thickness. This rind may be dry and gray or grayish-green, consisting of a felt-like surface of mold on the outside, below which a harder portion consists of mold embedded in partially dried cheese, or the moldy part may be more or less com- pletely overgrown or displaced by yellowish or reddish slime composed mainly of bacteria. Good cheeses may have either appearance. Inside the rind, the cheese is softened progressively from the rind toward the center from all sides, so that a fully ripe cheese has no hard sour curd in the center, but is completely softened. No mold should be visible inside the rind, but the moldy rind itself is necessary because the ripening is caused by the enzymes secreted by the organisms of the rind into the cheese. As the curd ripens, the changed portion assumes a slightly deeper color than the unripe curd as a result of chemical changes. Well-ripened cheeses vary from nearly a fluid texture to the consistency of moderately soft butter. The ripen- ing of Camembert is finished in wooden boxes which pro- tect the cheeses from breaking after they become soft and during the market period. 146. Conditions of making and ripening. — These pro- cesses depend on a very close adjustment between the com- position of the freshly made cheese and the temperature and humidity of the rooms in which the cheeses are made and ripened. Very slight failures in control bring loss in ultimate results. The room for making Camembert should be maintained between 60° and 70° F. and should be wet enough to reduce drying to a minimum. The essentials of apparatus are comparatively inexpensive. SOFT CHEESES RIPENED BY MOLD ud Work on a factory basis calls, however, for the installa- tion of special tables and other ai)paratus to utilize space and labor to advantage. Rooms are protected from change of feather by double sash in the windows. Flies must be excluded by close-meshed screens for all doors 120 THE BOOK OF CHEESE and windows with movable sash. The equipment in- stalled in such a room is shown in Fig. 18. Curdling cans are ranged on a shelf a few inches above the floor along one side of the room below an open tin trough with side branches. This open trough brings the milk from the mixing vat to the curdling cans. (The open tin trough offers no lodgment for dirt.) The cans hold about 200 pounds of milk, are about 12 inches in diameter at bottom, and 20 to 24 inches at top. They are heavily tinned. Iron trucks as high as the shelf and with tops the same diameter as the bottoms of the ,, ' cans form a con- "^ venient method of bringing cans of curd to the very edge of the draining tables. The wooden draining tables are placed about 32 inches above the floor ; they are usually made of 2-inch lumber, have raised edges and slope slightly toward the wall. Whey and wash water are thus carried to a draining trough along the wall. For cheese-making, each is covered with a strip of matting consisting of wooden strips held together by thread (Fig. 19). The strip of matting should be exactly the width and length of the table. The hoops used are heavy tin, with edges turned and soldered, about 5 inches high, 4f inches in diameter with three rows of Fig. 19. — Draining mat for Camembert cheese. SOFT CHEESES RIPENED BY MOLD 121 holes about tV inch in diameter and 2 inches apart in the row. These hoops are placed as thickly as possible upon the mats. 147. Outline of making process. — The making process ^ is summarized as follows (Thom, 1909) : Starter. — From 0.5 to 1.0 per cent of active starter is added to milk kept overnight below 60° F. Acidity at renneting. — Milk titrated to phenol- phthalein should test 0.20 to 0.23 per cent calculated as lactic acid. Temperance of renneting. — 84°— 86° F. is used for Camembert. Rennet. — From 3 to 5 oz. of standard rennet extract to 1000 lb. milk (10-15 c.c. per 100 lb. milk) produces a curd of proper texture. Curdling time. — To reach the proper condition for handling, \\ to li hom"s or longer is required. This is indicated by the onset of " sweating " or the separa- tion of large drops of whey on the surface of the solid curd. Dipping. — A long-handled dipper is used to transfer curd from cans to hoops. This can be lowered into the hoop. This transfer is to be done with the least pos- sible breaking. One dipperful is transferred at a time to each of a series of hoops. By the time the series is covered, some drainage has occurred and a second dip- perful is added to the contents of the hoop. In this way the hoop is filled within a period of two to four hours. Draining. — Hoops when properly filled have taken in approximately 2 quarts of milk each. No pressure ^ Lot record cards for the making and ripening of Camembert are given on pages 124 and 125. 122 THE BOOK OF CHEESE is used. Cheeses drain by gravity. They stand un- turned until the following morning when they should be firm enough to permit turning without removing the hoops. The cheeses when firm enough to handle (usually on the third morning) are salted by dusting the entire surface with coarse salt and permitting all that adheres to remain. The cheeses should then be removed to a room at about 58° F. to prevent too rapid leakage of water and salt from their surfaces. Ripe cheeses of good qual- ity show a total salt-content varying from 2.25 to 3 per cent with an average of about 2.5 per cent. When so handled there is slight, if any, loss of water and salt in the salting period of twenty-four to forty-eight hours. At the end of the salting period such cheeses should carry 55 to 57 per cent water or slightly more. 148. Acidity. — The essential biological factor in the making period of Camembert is proper souring. The milk should be free from gassy organisms. The lactic starter required should introduce the tji^ical lactic organ- ism {Streptococcus lacticns) in numbers sufficient to sup- press all other forms during the next twenty-four hours. The amount of acid starter introduced, however, plus the acid resulting from growth during the curdling period, should not produce a grainy acid curd. The tempera- tures of handling are such as to favor this group of organ- isms if properly introduced and permit the development of nearly 1 per cent of acid (estimated as lactic) by the second morning. Cheeses with such acid are fairly free from further danger from bacterial activity. IMembers of the high-acid group {B. Bulgaricus and allies) may be found in these cheeses but do not appear to develop in numbers sufficient to affect the cheese to any marked degree. SOFT CHEESES RIPENED BY MOLD 123 149. Ripening the cheese. — The cheese is now ready for the ripening rooms (Fig. 20). For this process tem- peratures between 52° and 58° F. are desirable ; lower Fig. 20. — Halloir, the first ripening room for Camembert in nn Americun factory. 124 THE BOOK OF CHEESE CAMEMBERT CHEESE RECORD Date..... Set No. Amt. milk No. cheese. Milk per cheese._ Producer of milk Apparent cleanliness of milk Acidity : Before adding starter After adding starter. After acidity period Whey at dipping Starter : Kind Age Amt Color : Amount Curdling : Temperature used Amount of rennet. Time at which rennet is added Time at which milk is ciirdled.. Time of curdling Quality of curd -- Dipping : Cut or uncut Amt. of cutting.„ Draining : Temperature of room during Condition of cheese after. Salting : Time of Total amt. of salt used Kind of salt.. Amt. of salt per cheese Mold inoculation : Form of culture used Method of inoculation Time of inoculation Remarks on making : Curing : Transfer of curing rooms Condition of cheese Rooms Dates SOFT CHEESES RIPENED BY MOLD 125 Mold growth : Date of first appearance Purity and vigor Date of changing color Surface of slimy growth : Extent of General character of Surface contamination : Mold Oidium Yeast... Bacterial Wrapping : Date Material. Condition of cheese Ripening : Rapidity of Texture Flavor : Ripened curd Unripened curd Special treatment and reasons for same : Record of treatment l\v days Room Date Observations. 1 D 2 D 3 D 4 D 5 D 6 D 7 D 8 D 9 D 10 D 11 D 12 D 13 D 14 D 15 D 16 D. 17 D. 18 D. 19 D. 20 D. 21 D. 22 D. 23 D. 24 D. 25 D. 26 D. 27 D. 28 D. 29 D. 30 D. 31 D. 126 THE BOOK OF CHEESE temperatures only delay the process ; higher temper- atures favor undesirable fermentations. The cheeses rest upon coarse matting (Fr. clayons) consisting of round wooden rods about the size of a pencil separated 1-1:|- inches and held in position bj^ wire strands. As- suming cheeses of optimum composition as indicated above, the relative humidity of the ripening rooms should be 86 to 88 per cent. Higher humidities produce too rapid development of slimy coatings ; too low humidity is indicated by drying, shrinkage and the growth of green molds on the surface. A slight and very slow evapora- tion is demanded ; by this the water-content of the cheeses is reduced 3 to 6 per cent in two weeks. During the first two weeks of ripening, the cheeses commonly show some growth of yeast and Oidiiini loctis first, followed by cottony white areas of Camembert mold (PeuiciUium Camemberii). This mold must be introduced by inocu- lation in new factories but once firmly established in the factory will propagate itself if conditions are kept favorable. Climatic conditions in most dairy sections of America have been sufficiently unfavorable to make more or less continuous use of pure cultures desirable. At the end of two weeks, Camembert cheeses should show a well-established rind, consisting of a well-matted felt work of mold hypha? through the outer 2 mm. (^^ inch) of the whole surface of the cheese. ]\Iore or less of the pale gray-green fruit of the characteristic Penicillium Canienibcrti can usually be seen. Beginning at about twelve to fourteen days,^ a softening of the curd is first * Bosworth, A. W., Chemical studios of Camembert cheese, N. Y. (Geneva) Exp. Sta. Tech. Bui. 5, pages 23-39. 1907. Dox, A. W., Proteolytic changes in the ripening of Camembert cheese, U. S. Dept. Agr. Bur. An. lud. Bui. 109, pages 1-24, 1908. SOFT CHEESES RIPENED BY MOLD 127 directly detectable under the rind. This is preceded by the disappearance of the acidity of the curd, which pro- gresses inward, "^rhe softening of the curd follows closely the lowering of the acidity. Thus a litmus test taken along the cut face of a Camembert cheese at any stage of softening will always show a sharp acid reaction in the solid sour portion which changes to alkaline just before the softening due to proteolytic action becomes noticeable. These two changes appear to be due to en- zymes secreted by the mycelium of the PeniciUkim Camem- bert i and Oidium lactis which constitute the most active factors in the ripening. Some accessory bacterial action is indicated but of minor importance in the changes foinid. To avoid k)ss from breaking, after the softening of the curd has fairly begun, the cheeses must be removed from the coarse matting to smooth boards where they are watched and turned repeatedl.>% or as in the more common practice, wrapped at once in parchment paper and boxed. The ripening may })e completed in either way. The conditions necessary are such as to favor the extension of slimy areas of bacteria over part or all of the rind to the exclusion of further development of gray-green fruit- ing areas of mold. Complete softening may occur in three weeks in cheeses in which evaporation has gone on too slowly. Such cheeses are found to contain 51 to 55 per cent of water when ripe and decay very quickly. If handled properly, the water-content should fall from about 57 per cent at the beginning of ripening to 48 per cent at its completion which should require a minimum period of about four weeks. It is more desirable that a cheese four weeks old show a thin core of sour curd in the center than that it be entirely liquid at that age. 128 THE BOOK OF CHEESE 150. Composition. — Properly ripe Camembert shows about the following range of composition : Water 47 to 49 per cent ; fat 25 to 28 per cent ; protein 18 to 21 per cent; salt 2.2 per cent to 2.8 per cent. Variations out- side these limits are usually associated with less desirable qualities. The approximate limits and characters out- lined for Camembert still leave a considerable latitude for variations in practice which characterize the output of particular factories in a producing group. At one Fig. 21. — Very soft Camembert cheese. extreme are brands of Camembert cheese which are very soft (Fig. 21), some of them actually liquid when ripe, and which have very strong odor and taste ; one such brand has held first place in the trade of certain American cities for years. Another popular brand when fully ripe is well covered with yellow-orange viscid slime ^ but is 1 Esten, W. M., and C. J. Mason, Bact. Stud, of Camembert cheese, Storrs Exp. Sta. Bui. 83 (1915), pages 103-111. SOFT CHEESES RIPENED BY MOLD 129 fairly firm in texture with high flavor ; still others show dry moldy surfaces and mild flavors. The product of certain factories is always characterized by the presence and characteristic ammoniacal odor of Penicillium bre'vi- caule. Each of these forms seems to appeal to some classes of consumers, so that in handling imported Camembert the trade comes to assign the product to specific groups of purchasers according to the conditions observed at its arrival from Europe. 151. Factory. — The type of factory to be used in making and ripening Camembert must be adjusted to Fig. 22.- • Camembert cheese factory at Lisieux, France, windows are seen in the second-floor rooms. The square the climate. This- product originated in the Normandy section of France which is but a few feet above sea level, is swept by winds from the Gulf Stream, and has a narrow range of temperature, with highly humid conditions. In that region, every effort must be made to secure ventila- 130 THE BOOK OF CHEESE tion to carry off the necessary amount of evaporation water. In contrast, most of the dairy sections of America have land instead of sea breezes, much higher altitudes, much greater extremes of temperature and a lower range of relative humidities. The conditions of an upstairs room full of windows in Normandy (Fig. 22) are most readily reproduced in rooms partly or completely be- low ground in this country. The industry calls for the production and maintenance of a specific set of working conditions. These are furnished by nature in northern France, probably also in certain Pacific coast areas, but must be artificially obtained where the climate is un- favorable. 152. Economic factors. — Camembert cheeses show a yield of about 13 pounds to 100 pounds of milk testing 4 per cent fat. At roughly one-half pound each, the number of cheeses will be approximately twenty-six. Assuming no losses and a wholesale price of 15 cents each, the wholesale value of 100 pounds of milk would be $3.90. The labor cost of i)roduction is high, the pack- age represents (box, wrapping and label) at least 1-|- cents a cheese. The time between the purchase and the consumption of the cheese will average about one month. Few cheeses actually remain this length of time in the possession of the maker. This short investment period, therefore, is a distinct advantage of Camembert. Among disadvantages, however, the extremely perishable char- acter of the fully ripe cheese makes provision of an ade- quate and constant market essential. Losses due to failures in manufacturing or ripening conditions are also frequent. Excessive heat in summer and very cold periods in winter are both unfavorable. The Camembert- maker cannot, therefore, use the cheapest milk of the SOFT CHEESES RIPENED BY MOLD 131 summer months at all and the losses entailed by failure of control in winter fall on the most costly milk of the year. Camembert requires, therefore, careful selection of the location for manufacture and ripening, effective control of conditions throughout the period and adequate marketing facilities. Camembert at its best is one of the finest of all cheeses ; when bad, it becomes quickly inedible and is a total loss. 153. French Brie.^ — Brie cheese has its center of production in Seine-et-Marne, east of Paris in northern France. The apparatus, arrangement of the factories and details of manipulation differ from those described for Camembert, but the final product is in flavor and texture closely related to Camembert. Brie cheeses are the same thickness as Camembert, 1 to 1^ inches ; in diam- eter, however, there are three or more sizes varying from 8 to 16 inches, or even greater. The largest cheeses weigh 5 to 6 pounds. As in Camembert, practices of making and ripening vary to such a degree as to produce various qualities of product. These run from whole milk through all shades of skimming. Perhaps the best established practice puts the cheese -making room next to the stalls of the cows. The milk is drawn, strained directly into the curdling cans and renneted while still warm, — 86-92° F. (30-33° C). No lactic starter is added and no ripening period is given to the milk. The other manipulations differ only in detail from Camembert. Ripening of Brie follows the same course with the same organic agents, namely, Camembert mold (Penicillium Camemherti) and Oidium lactis with the accompaniment of a mixture of slimy organisms upon the surface of the ^ See page 134 for domestic or American use of the name Brie. 132 THE BOOK OF CHEESE cheese. The process admits of many minor modifications each capable of affecting the product in a characteristic way. The judgment and skill of the maker is given a wide opportunity to establish and work toward a par- ticular ideal of appearance and texture and flavor. Brands with characteristic qualities, therefore, command their own market. Brie as known in France must not be confused with the American " d'Isigny," or with the particular sizes of that type which have been called Brie on account of diameter only. Very little Brie as known in France has been made in America and only a limited amount has been imported for very restricted trade. 154. Coulominiers. — Another member of the Camem- bert group is called, from its place of origin, Coulommiers. This form is made at the same thickness as Camembert and about 5i inches in diameter. It appears as either a ripened or unripe cheese. As a ripened cheese, Coulom- miers is not essentially dift'erent from Camembert except that some brands are made without salting. As a cheese eaten unripe, it has certain advantages over the other cheeses with the flavor of sour milk only. The cottage and (American) Neufchatel group of cheeses comprises the best known forms with the acid flavor. These cheeses are very perishable in nature. On the other hand, Coulom- miers as eaten fresh can be held and used over a much longer time without loss. Coulommiers ^ in this sense is simply a fresh Camembert. Such a cheese, when ready for the salting process, is a firm sour mass, close textured, almost impervious to air and but slowly permeable to liquids. Spoilage in such a cheese begins only on the 1 McNaughton, J., Coulommier eheese, Dept. Agr. Ottawa, Canada, Dairy and Cold Storage Ser. Bui. 25, 1910. SOFT CHEESES RIPENED BY MOLD 133 outside, and not throughout the mass as in cottage cheese or Neufchatel. Successive portions of such a cheese can be removed daily over a considerable period with no loss of substance aside from slight scraping at times and little or no change in flavor. This product has very tan- gible merit for manufacture and use on the farm in many sections of America. CHAPTER IX SOFT CHEESES RIPENED BY BACTERIA A BACTERIALLY-RIPENED sei'ies of clieeses parallels the mold-ripened group as typified by Camembert. Although the varieties overlap, these may be roughly grouped as : (1) those made from friable or soft curd ; (2) those made from firm or rubbery cinxl. In the first group, the curd is set at 86° F., or below; in the second, the rennet is added at 90° F. or abo^•e. In the first, the lower tem- perature and long curdling time with ripened milk gi\es a soft friable curd which may be toughened somewhat by cutting and stirring in the whey. This section is typified by d'Isigny, American Brie, Liederkranz. In the second, curdling of unripened milk at temperatures of 90° F. or above insures a smooth elastic curd which fuses more or less completely into the firm rubbery mass typified by freshly made Limburger. 155. The Isigny group. — A series of names, d'Isigny, Brie, Brie d'Isigny, combined with trade names, are used for a domestic cheese, made in a small number of factories distributed over New York, Pennsylvania, JNIichigan, Illinois, Wisconsin, Iowa and California. The cheeses sold under the separate varietal names dift'er only in diameter ; their thickness is fairly uniform ; the process of manufacture and ripening with resultant textures and flavors furnishes no fundamental varietal 134 SOFT CHEESES RIPENED BY BACTERIA 135 characters, although the products of the several factories show noticeable difi'erences in market quality. D'Isigny, while the name of a French town famous for butter production, is not used to designate a cheese in France. It may, therefore, be accepted as a French name arbitrarily applied to a domestic product. Brie as used in France is a markedly different cheese (p. 131), and the name should be dropped from this form as made in America. As used for a member of this series made in America, it merely means cheese 7 to 15 inches in diameter. The cheese partakes of the characters of French Livarot, and of Pont I'Eveque without exactly reproducing either form. The milk \aries from separator skim to whole milk, with resultant differences in quality. Freedom from gas is essential to the best results. The milk is curdled at 85 to 86 F. with sufficient rennet to produce a very firm curd within a period of one and one-half hours-. Curd is then cut in two directions, allowed to stand a few minutes or gently agitated to produce a very slight toughness or " worked " condition, then scooped into hoops 4| to 5 inches in height and ^'arying in diameter from 2^ to 15 inches according to the size selected for manufacture. To aid in the escape of whey, three rows of holes iV inch in diameter and 2 inches apart in the row are made in each hoop. The hoops are arranged upon draining tables with more or less corrugated surface, which for best drainage should be covered with matting. The cheeses are allowed to drain without pressure. They are commonly turned the second morning, although they are sometimes solid enough to turn within the first day. When fully drained, the cheeses are salted by rubbing coarse salt on the surface, after which they stand an extra day. They are then arranged upon shelves in a 136 THE BOOK OF CHEESE ripening room held between 50° and 60° F. with humidity so high that evaporation is kept at a minimum. In this room, a surface sHme develops quickly. This consists of bacteria of several forms, yeasts, Oidium ladis and accidental species of other molds. During this ripening, the cheeses are turned, rubbed with the hands, washed with salt water and scraped if infected with molds which produce colored colonies. In the course of ripening, the slimy surface layer acquires a yellowish orange color with the strong odor and taste characteristic of the series. Brands of d'lsigny are made from every grade between separator skim and whole milk. They reach the market in condition all the way from " Kosher " forms ^ which are eaten entirely unripe, to brands which approximate the qualities of Limburger and others which approach Port du Salut. The biology and chemistry of the ripening of this type of cheese have not been completely followed. An initial souring process always takes place quickly. Okluim ladis is always present in some degree on the surface, but the organisms in the yellowish to orange slime on the surface of the cheese appear to produce the characteristic odor and taste. These appear to be due to the develop- ment of volatile fatty acids, such as valerianic and ca- proic, which diffuse throughout the cheese, even pene- trating the unripened sour portions. The same odor and taste in varying intensity are present in Limburger, Brick, and a long series of German varieties not handled in America. High-flavored cheeses such as these, form an acceptable part of the meal in cases in which the intensity of other ^ Kosher forms are prepared in compliance with the Mosaic law as demanded by the Jewish trade. SOFT CHEESES RIPENED BY BACTERIA 137 flavors is such as to mask entirely the milder flavors of Camembert or cream cheese. In composition, a characteristic whole-milk brand of this group showed the following analysis : ^ water, 45.5 per cent; fat, 25.28 per cent; protein, 18.22 per cent. 156. Raffine.^ — This cheese is made in the French settlement of the Isle of Orleans in the St. Lawrence River. The practice seems to have been brought from France and represents an intermediate product between Camembert and perhaps Livarot, a cheese on the border- line between Camembert and Isigny as made in America. The outline of the making process as given follows : INIilk freshly drawn is curdled without cooling, at approxi- mately 90° F. The rennet is prepared on the farm. About one-half hour is required for curdling. The curd is cut into 2-inch cubes. Whey is removed as fast as it separates. About two hours are required for draining. The curd then goes into the hoops. The metal hoops, which are closed at one end, are 6 inches high, 4| inches in diameter, with holes about tV inch at intervals of about ^ inch, and stand upon three legs about 1 inch in height. When filled, the cheeses are left on a draining table. Some salt is put on top while draining. When the volume is reduced to one-half, the cheese is turned. The drain- ing room is kept at about 70° F. After they are firm enough to handle, drainage is completed on racks covered with rush matting. These are arranged on special racks. The cheeses are turned twice a day, and washed in slightly 1 Unpublished analysis of the Storrs Exp. Sta. 2 Chapais, J. C, Monographie, Le Fromage Raffine de L'Isle d'Orleans. Quebec, 1911. Published by Ministry of Agricul- ture, pages 1-31. 138 THE BOOK OF CHEESE salted water every two days. After each washing, they are drained for two hours on cloth, and placed on clean matting. This treatment continues about fifteen days. After fifteen days on the matting, the cheeses are ready for ripening. They are first covered with cold brine and let stand twenty-four hours. The cheeses are packed in rolls or tiers in boxes, covered with cloth and ripened at 45° F. They must be kept moist; if signs of drying appear, moisture must be added. If the cheeses develop yellow slime, they are washed with clear water and rinsed in water with salt added. x\fter a ripening period of three weeks, the cheeses should begin to be soft when pressed with the finger. The growth of molds must be prevented by washing the boxes, cloths, and washing and scraping the cheeses if necessary. When the cheeses are ready for the market, they are scraped clean and white, wrapped separately in cheese-cloth or parchment paper and packed into the boxes. Ripe cheeses are about 5 inches in diameter, 1 inch thick and weigh a little over 5 ounces. The outline of the Raffine process follows : coagulation by rennet 30 minutes cutting and draining curd .... 2 hours draining in hoops . . . . . . 10 hours stand on mats 15 days ripening in boxes 21 days Total period 36 days The treatment described closely resembles the handling of Livarot cheese in the department of Calvados, France. 157. Liederkranz cheese. — Among the specialties in the bacterial group is Liederkranz, made from curd with the soft friable texture of a Camembert, molded in rec- SOFT CHEESES RIPENED BY BACTERIA 139 tangiilar blocks of about 4 ounces in weight and ripened ver3' com])letely. Although this name is the private brand of a single factory, it has become widely known with the effect of creating a type name in the American market. Analysis of this brand of cheese gives about 55 per cent water, 25 per cent fat, 17 per cent protein, which in- dicates a whole milk cheese. 158. Limburger cheese ^ derives its name from the town of Limburg in Belgium. The manufacture of this cheese is now widely practiced in Europe and in certain parts of the United States, especially in New York and Wisconsin. Practically no cheese of this name is at present imported, and the practices described are limited to those in American factories. 159. The milk. — Limburger cheese is probably best known on account of its pronounced odor. Because of this characteristic pungent smell, it is often thought that the cheese is made in dirty or misanitary places. On the contrary, Limburger cheese is usually made in small factories which are clean and sanitary. Because of the constant attention required, a cheese-maker can handle only about 2000-2500 pounds of milk a day, and then some help is necessary to care for the cheeses in the curing room." The • discussion of the milk given in Chapter II applies to that to be made into Limburger cheese; however, Limburger requires sweeter milk than do some of the other types. To be sure of obtaining very sweet milk, it is the usual practice for the milk to be delivered without cooling morning and evening ^ The authors acknowledge the assistance of Mr. Louis Get- man in preparing this description. ^ Zumkehr, P., Liml)urger cheesemaking, Wis. Cheese-makers Association, 15th Annual Meeting, 1907, page 62. 140 THE BOOK OF CHEESE at the cheese factory. The cheese is made twice a day. Because the milk must be dehvered twice daily, it is obtaiued from only a few producers near the factory. A factory usually does not have more than eight to twelve patrons. Because of the small number of patrons, it is comparatively easy to obtain a supply of fresh clean milk. The factories are variously built. A common type takes advantage of sloping ground so that the floor at Fig. 23. — A common type of Limburgcr cheese factory. one end may be on the ground le\'el and run backward into a hillside until the other end is a cellar with small windows at the ceiling opening at the ground level (Fig. 23). The family of the cheese-maker often lives in the same building above the factory. 160. Making the cheese. — Limburger cheese is made from the whole milk. When the milk is received at the factory, it is placed in the cheese vat. As the milk is delivered both morning and evening without cooling, it reaches the factory at a temperature of 90 to 96° F. SOFT CHEESES RIPENED BY BACTERIA 141 In some cases the night's and morning's milk is mixed and then warmed to about 94° F. This practice is not recommended but is frequently adopted, when the supply of milk becomes too small to work in two lots. As soon as all of the milk has been delivered, the cheese-making process begins. No starter is used. The milk is not ripened because no acid development during the making process is desired. The milk is set or curdled at the temperature at which it is received at the factory, usually from 90 to 96° F. Sufficient rennet extract is used to give a firm coagulation in twentj^ to thirty minutes. This usually reciuires 2|- to 3 ounces of rennet extract for each 1000 pounds of milk. This is diluted in about forty times its own volume of cold water and added to the milk. (For method of adding rennet extract to milk, see Chapter V.) When the coagulum has become firm so that it will split clean over the finger, the curd is ready to cut. Coarse Cheddar cheese knives are used. Sometimes only the perpendicular knife is employed, and the curd is broken up whileS^eing stirred with the hands and rake. This usually causes a large fat loss. After cutting, the curd is stirred first by hand and later with an ordinary wooden hay rake. Usually the curd is not " cooked " or heated after setting, though occasionally it is brought up as high as 96° F. to 98° F. If the curd does not firm up, the temperature may be raised to 98° to 100° F. to aid in expelling the moisture. When ready to dip, the curd should still be in large soft shiny pieces. It requires from one hour to an hour and thirty minutes from the time the rennet extract is added until the curd is ready to dip. When, in the judgment of the cheese-maker, the curd has become suffi- 142 THE BOOK OF CHEESE ciently firmed in the whey, the whey is drawn down to the surface of the curd. The curd is then dipped into the Liniburger molds. These molds are 5 inches square by S inches deep without top or bottom. Usually there are five or six of these molds built together into a section. These molds are placed on a draininij; table beside the \at and the curd is ladled into them with a large tin ladle. The draining table has strips on both sides and one end and slants toward the other end so that the whey will drain from the curd and yet not go on the floor except at the one end. This makes it easy to save and catch the whey for stock feed. 161. Draining and salting Limburger. — In some fac- tories, a clean piece of burlap is put on the draining table and the molds and curd placed on the burlap. This aids in the rapid draining of the whey from the curd and pre- vents the loss of curd particles. The curd should be turned frequently in the mold to obtain uniform draining. The molds are transferred to the salting room as soon as well drained, usually in about twelve hours, but sometimes they are left until the following morning. Here they are placed on another draining table, which has strips about 5 inches high on the sides and one end. Th^ cheeses are placed along this board, each cheese being separated by a piece of board 4 inches high and 5 inches wide. When the row is filled, a long strip the length of the table is placed against the row. Another row is laid down against this strip in the same manner as the first, and so on until several rows are on the table. The last long strip is held firmly in place by sticks wedged between it and the opposite side of the table. These strips and pieces form a mold for each cheese while draining. Usuallv the cheeses are turned several times SOFT CHEESES RIPENED BY BACTERIA 143 in this period to obtain a uniform expulsion of whey. In about twenty-four hours the cheeses are ready to be salted. This is done by applying the salt to the outside of the cheese. The edges are rolled in a box of salt and the salt then rubbed on the two broad surfaces. Any excess salt is brushed from the cheese with the hand. The cheeses are then laid on a draining table in single layers. The second day, they are salted again in the same way and piled two deep ; they are salted again the third day and piled three or four layers deep. The salting room or cellar should have a temperature of 60° F. and be fairly damp. The amount of salt used is very important. The tendency is to use too much salt. This retards the ripening process and in extreme cases gives the cheese a salty taste. If not enough salt is used, the cheese will deteriorate very rapidly on ac- count of the development of undesirable types of fer- mentation. The cheeses when salted are then placed in the curing room, which is a cellar, usually beyond the salting room. This cellar should have a temperature of 58 to (34 F. and a relative humidity of 95 per cent of saturation. In winter it is necessary to have a fire to keep the rooms warm, otherwise the cheese would cure very slowly or not at all. In some factories the curing and salting cellars are a single room. 162. Ripening Limburger. — When first placed in the curing cellar, the cheeses are put on edge close together, and as they cure are gradually separated. While in the curing cellar, the cheese must be rubbed frequently by hand and washed, usually with salt water. The object of the rubbing is to keep the surface of the cheese moist and prevent the growth of molds. The drier the cheese and the more mold, the oftener the cheeses must be 144 THE BOOK OF CHEESE rubbed. The drying or the evaporation from the cheese can be retarded by sprinkHng the floor of the cellar with water. When first placed in the curing cellar, they are usually rubbed daily ; after a few days they are rubbed every other day and finally as often as the cheese-maker can find time to work at them. The more the cheeses are rubbed, the better the rind. In the curing of Limburger cheese, protein compounds are attacked by the micro-organisms. Certain highly- flavored fatty acids are commonly produced.^ This change works most rapidly near the outside and more slowly toward the center of the cheese. The stage of ripening can be determined by examining the cheese. When first made, a cheese is harsh and hard and the outside is more or less white : as the curing changes take place, the cheese becomes soft and pasty or buttery. The outside color changes from a whitish to a yellowish and finally even a reddish brown. It requires consider- able time for the ripening agents to work from the outside to the center of the cheese. As ripening progresses, Limburger cheeses tend to become soft enough to break in handling. If such cheeses are wrapped in manila paper after three to four weeks of ripening and packed in boxes, losses from handling are eliminated. One loose board is left on each box and the boxes remain in the ripening cellar until the cheese-maker decides by removal and examination of cheeses from time to time that they are ready for shipment. When fully ripe, the cheese spoils very quickly. Unless handled very carefully, the outer part may actually rot before the interior is fully ripe. The cheeses are shipped from the ^ Currie, J. N., Flavor of Roquefort cheese, Jour. Agr. Re- search 2 (1914), no. 1, pages 1-14. SOFT CHEESES RIPENED BY BACTERIA 145 factory when they are eight to ten weeks old. They are then phiced in cold storage, which checks the action of the ripening agents and so lengthens the commercial life of the cheese. 163. Marketing and qualities of Limburger. — As shipped from the factory, each cheese is wrapped in heavy manila paper and frequently also in tin-foil. The cheeses are packed in boxes which hold forty-eight. Each cheese weighs about two pounds. Limburger cheese should be regular in shape. The rind should not be cracked or broken nor the sides bulged, nor should it be lopsided. It should have the pronounced characteristic flavor, without other objectionable flavors due to undesirable fermentations. The bod}^ should be uniform throughout. It is common to find cheeses that have not a uniform body, due to lack of curing ; a small part of the interior at the center will be hard and not cured, while the remainder of the cheese will be soft and buttery. The color should be uniform. When not en- tirely cured, the uncured part at the center is usually of a lighter color. The cheese should contain the proper amount of salt. The most common defect is in the flavor. If the milk is not free from bad odors and flavors, these are apt to be more pronounced in the cheese than in the milk. (For care of milk see Chapter II.) Gas-forming fer- mentations are very bad in this variety of cheese as they cannot be controlled and give the cheese a bad flavor and a " gassy body." When a cheese is gassy, the sides are most liable to be bulged and the body is full of gas holes or pockets. Another defect is a sour cheese. This is caused by the development of too much acid in the milk or during the manufacturing process. A sour 146 THE BOOK OF CHEESE cheese usually cures slowly and has a pronounced sour taste. The body is hard and bitter. If the cheese contains too much moisture, it will cure rapidly and the body will be very soft and pasty. In extreme cases it will be so soft that it will run w^hen the rind is broken. On the other hand if the cheese does not contain sufficient moisture, it will cure very slowly and the body will be hard and dry and sometimes crumbly. There is no standard score-card for judging Limburger cheese. The Wisconsin Cheese-makers Association ^ uses the following score-card for Limburger : Flavor 40 Texture 40 Color 10 Salt 5 Style _5 Total 100 164. Yield and composition of Limburger. — The yield of cheese depends on: (1) the amount of fat and other solids in the milk from which it is made ; (2) the amount of moisture incorporated into cheese; (3) the loss of solids during the manufacturing process. The yield A-aries from 12 to 14 pounds of cheese from 100 pounds of milk. The more fat and other solids in the milk, the more cheese can be made from 100 pounds of the milk. The more moisture incorporated into the cheese, the larger the yield. The quality of the cheese and the amount of solids determine the amount of mois- ture that can be incorporated into the cheese. The greater the losses during the manufacturing process, the * Wis. Cheese-makers Assoc, 12th Annual Meeting and Report, 1906, page xx\iii. SOFT CHEESES. RIPENED BY BACTERIA 147 less is the yield. The composition of Limburger cheese is affected by the same factors as the yield. The average cheese probably carries from 40 to 42 per cent of moisture. Limburger cheeses will vary in composition from this analysis about as follows : water 38 to 44 per cent, protein 21 to 25 per cent, fat 25 to .30 per cent. The differences in practice in factory groups are considerable. Certain markets call for more solid brands, others for the very soft forms. 165. Miinster cheese originated in Germany near the city whose name it bears. There is a limited de- mand for this variety in America ; therefore it is not extensively made. It is usually manufactured from whole milk in a Limburger or Brick cheese factory. The process of manufacture is between that of these two varieties in temperatures used, firmness of curd and amount of moisture in the curd and cheese. The process is prob- ably more like that of Limburger. The curd is firmed more in the whey than for Limburger, and more acid is developed. The cheeses are pressed or drained in round forms 7 inches in diameter and 6 inches high. The hoops are lined with cloth to prevent the loss of curd particles while draining. When the cheeses are sufficiently drained, until they are firm enough to hold their shape, the cloths are removed. The cheese is salted by rubbing dry salt on the surface or soaking the cheese in brine. The prod- uct is handled in the curing room very much the same as Limburger or Brick cheese. When sufficiently ripe, each cheese is wrapped in parchment paper and placed in a separate wooden box. This cheese, when cured, has a characteristic flavor which is between that of Limburger and Brick. The body is more or less open. The essential factor in the manufacture of IVIiinster cheese is clean 148 THE BOOK OF CHEESE milk. Bad fermentations, such as produce gas and bad flavors, seriously interfere with the manufacture and sale of the product. The cheese is usually made in the late fall and winter, when it is difficult to manufacture Limburger. CHAPTER X SEMI- HARD CHEESES Between the quickly perishable soft cheeses and the typical hard group, are two series of varieties, one ripened by green mold and best known by Roquefort, the other ripened by bacteria and typified by Brick cheese. These cheeses are fairly firm, hold their shape well, ripen over a period varying from a few weeks to several months and their marketable period is com- paratively long. In texture they are intermediate be- tween the conditions known as " soft " and " hard." In water-content, they range at their best from 37 to 45 per cent. Outside these limits, the cheeses are often marketable but they lose in quality ^ and trueness to type. 166. The green mold group. — There are three well- known semi-hard cheeses ripened by green or blue-green mold.^ The mold is an incidental factor in certain other forms but none of these forms has won larger than local or purely national recognition. French Roquefort, on the contrary, is probably the most widely known of all cheeses. Stilton, to a small degree at least, has followed the English to the many lands they inhabit. Gorgonzola, although ^ Currie, J. N., The relation of composition to quality in cheese, American Food Jour. 11 (191G), no. 9, page 4.58. See also Dox on the True Composition of Roquefort Cheese, Ztsch. Untersuch. Nahr. u. Genussmtl. 22 (1911), pages 239-242. 2 Thom, C, and Matheson, K. .J., Biology of Roquefort cheese, Storrs Exp. Sta. Bui. 79, pages 335-347, 1914. 149 150 THE BOOK OF CHEESE made in Italy alone, has a large market in other parts of Europe and in America. In the manipulations of manu- facture, these forms are not closely related but they re- semble each other in that each becomes streaked or marbled by the growth of green mold {Penicillium Roque- forti) through open spaces within the cheese. The *' blue-veined " or marbled cheeses have a characteristic taste which is developed in its most typical form in Roquefort. 167. Roquefort cheese. — This is a rennet cheese made from sheep's milk (with occasional and minor admixture of goat's and cow's milk) in the section of southern France centering about Roquefort in iVveyron. The practices are standardized and controlled by a few companies, thus reaching exceptional uniformity. Roque- fort is uncolored, open, made from firm but brittle or crumbly, not tough or waxy curd. Each cheese is about 7j inches (20 cm.) in diameter and oj inches (9 cm.) in thickness without a definite rind, and when ripe enough for market is scraped carefully, closely covered with tin-foil and kept in refrigerators. The cut cheese shows extensi\e open spaces which are lined with green mold. This cheese, in addition to a strong cheesy odor and taste, has a peppery or burning quality which according to Currie ^ is due to the formation of volatile fatty acids such as caproic, caprylic and capric from the butter-fat of the sheep's milk used. A series for Roquefort cheeses selected for excellent quality was found by Dox - to show the following composition : ^ Currie, J. N., Flavor of Roquefort cheese, Jour. Agr. Re- search, 2 (1914), 1, pages 1-14, Washington. 2 Dox, A. W., Die Zusammensetzung des echten Roquefort- Kases, in Ztsehr. Untersuch. Nahr. u. Genussmtl. Bd. 22, Heft. 4, pages 239-242, 1911. SEMI-HARD CHEESES 151 TABLE IV Composition of Roquefort Cheese Water Per Cent Fat Per Cent Protein Per Cent Ash Per Cent Salt Per Cent Average .... Minimum . . . Maximum . 38.69 37.49 40.10 32.31 31.50 33.53 21.39 19.14 23.06 6.14 5.18 6.81 4.14 3.64 4.88 The composition of the sheep's milk of the Roquefort producing region is reported by Marre : ^ TABLE V Composition of Sheep's Milk Water Per Cent Casein Per Cent Fat Per Cent Lactose Per Cent Ash Per Cent Range .... Average .... 76-83 79.5 5-8 6.5 5.5-10.5 8.0 4 to 5 4.5 0.8-1.2 1.0 The cheeses when properly made in the local factories are transported to Roquefort for ripening in the famous caves which have made possible the development of a great industry. The Roquefort caves were originally natural openings leading back into the face of a cliff until they reached a deep, narrow fault or crack in the rock leading to the plains above. The cooler air from the plains came down this crack over moist and dripping rocks and issued through these clefts in a cold moisture-laden current which kept the caves about 50 to 55° F. and moist enough to ripen the cheeses without shrinkage. As the business 1 Marre, E., Le Roquefort, Rodez, 1906. This is the authorita- tive monograph on Roquefort cheese problems. 152 THE BOOK OF CHEESE outgrew the natural caves, great cellars, some of them five or six floors deep, were excavated and tunnels were dug back to the crack so that the strong ventilating current reaches every part of the cellars and keeps both temperature and relative humidity favorable to the ripening of the cheeses. 168. Cow's milk or Facons Roquefort. — The supply of Roquefort is automatically limited by the supply of sheep's milk. The sheep gives milk only about five months in the year and at best a scant average of about a pint a day to a sheep. Sheep's milk for cheese-making is not produced, therefore, outside of very limited regions. Some cow's and goat's milk unavoidably finds its way regularly into the industry itself. x\ttempts were nat- urally made to substitute cow's milk. Outside the con- trolled area, factories were established for this purpose. The quality of the product did not equal that of the Roquefort factories, and French courts decreed that the name Roquefort should not be used for such products. Although some local success was obtained, not much prog- ress was made against the intrenched Roquefort industry. Similar attempts to make such a product in Germany ^ were tried on an extensive scale but failed. More re- cently, under the inspiration of Conn, the United States Department of Agriculture and the Storrs Experiment Station hdve studied the possibilities of such an industry. Although the work is not completed, the preliminary reports ^ have indicated the fundamental principles which must underlie such development. ^ Reported on the word of Prof. Fleischmann. ^ Thorn, C, J. N. Currie and K. J. Matheson, Studies relating to the Roquefort and Camembert types of cheese, Storrs Exp. Sta. Bui. 79, pages 335-394, 1914. SEMI -HARD CHEESES 153 169. Outline of making Roquefort. — Some of the results of these experiments are summarized in the fol- lowing paragraphs : Milk. — Clean-flavored fresh milk testing 4-4.2 per cent fat and up to 2.8 percent casein gives the best results. The milk with a high percentage of cheese-making solids forms a firmer curd, hence works up better in the process than milk of lower quality. Acidity. — The milk is ripened by lactic starter up to an acidity of 0.23 per cent titrated as lactic acid at the time rennet is added. This gives a firm curd, which drains to the desired water-content but is low enough to prevent the toughening efl^ect of too high acid. A very slight increase in initial acid — 1 to 2 hundredths per cent — combined with the rate at which acidity is developing introduces such physical changes in texture as to make the final texture of Roquefort impossible. Temperature. — Rennet is added at or below 84° F. Every degree of heat adds definitely to the efficiency of rennet. Below 82° F., curdling becomes slower and the coagulum softer and more difficult to drain. The sheep's milk curd is made from 76° to 84° F. but sheep's milk has about twice the cheese solids found in cow's milk. It was found necessary to raise the temperature as high as texture would permit. However, at 86° F. the physical character of the curd tends to become tough or waxy in handling. At 84° F. the curd remains brittle and crumbly. It was, therefore, necessary to keep the cur- dling temperature down to 84° F. Renneting or setting. — Rennet at a rate of 3 to 4 ounces of standard liquid rennet to 1000 pounds (10 to 12 c.c. to 100 pounds) was found to give the best curd under experimental conditions. 154 THE BOOK OF CHEESE Curdling time. — One and one-half to two hours gave most satisfactory results in forming curd. This should be very firm and stand until it begins to " sweat," luitil beads of whey have begun to collect upon its surface. Cutting. — The cow's milk curd gave best results when cut in two directions with the half-inch curd knife. The resulting columns, a half inch square in cross-section, may be handled without excessive losses. Draining. — The cut curd is dipped to a draining rack covered with cloth with as little breaking as possible. During the draining process, a certain amount of turning is necessary to facilitate the separation and escape of the w^hey. If handled too much, losses of fat are in- creased and the curd becomes tough or waxy instead of remaining brittle or crumbly. When properly handled, not over 0.35 per cent of fat is lost. Under favorable conditions, four-ninths to two-thirds of the original weight of curd will separate and run off as whey in twenty to thirty minutes. The curd meanwhile is exposed to the air of the room and cools toward room temperature. If cooling goes too far, further drainage is interfered with. Hence the curd is put into the hoop and the drainage completed while the cheese is reaching its final form. Hoop. — Hoops for cow's milk Roquefort must be 7 J inches in diameter and about 5f inches high to hold curd enough to produce a cheese the size of the standard Roquefort when completely drained. Sheep's milk with its higher percentage of solids does not require such high hoops. The curd as it goes into the hoop should be a soft, pulpy mass with no suggestion of toughness. Inoculation with mold. — The mold for Roquefort cheese {Penicillium Roqueforti ^) is readily grown in pure 1 Thorn, C, U. S. Dept. Agr. Bur. An. Ind. Bui. 82, 1905. SEMI-HARD CHEESES 155 culture in ordinary loaves of bread. For this purpose loaves hot from the oven are quickly drenched with or immersed in hot parafRne to form an impervious crust to retain moisture as well as to keep out contaminations. It is then allowed to cool. The interior of each loaf is inoculated by drawing a suspension of P. Roqueforti spores in water into a sterile pipette (10 c.c.) which is then thrust through the paraffined crust to the center of the loaf of bread and allowed to empty there. The hole is sealed up with paraffine. These loaves are incubated for about a month at room temperature. When cut, every open space should be found lined with the green spores of the mold. When dry enough, the mass may be powdered, and put into an ordinary pepper box. When the curd is ready to go into the hoop, this mold powder is sprinkled upon it from the pepper box. HandUng. — Freshly made cheeses are turned within the first hoar to insure the proper smoothness of both sides. Further draining is best accomplished in a room at about 64° F. with a relative humidity of 85 to 90 per cent. If the surface of the cheese becomes too dry, a rind is formed. No real rind is permitted on Roquefort. If the temperature is too high, slime forms quickly and unfavorable fermentation may occur. Slime (bacteria and Oidium lactis usually) must be scraped when it becomes too heavy. Salting. ^ — Experimental cheeses were found to give the best results when at the end of about three days' drainage they contained about 50 per cent water. Such cheeses were salted by sprinkling the entire surface lightly, replaced upon the drain boards for one day, ^ Thorn, C, The salt factor in the mold ripened cheeses, Storrs Exp. Sta. Bui. 79, pages 387-394, 1914. 156 THE BOOK OF CHEESE salted again and piled in two's. After another day they received the third salting and were piled in three's for two days longer. A total of about 10 per cent by weight of salt was used to secure an absorption of 4 per cent. At the same time the water-content dropped to 40 to 43 per cent. After salting is completed, the cheeses are brushed and punched with holes to permit oxygen to enter.^ They are then ready for ripening. 170. Ripening of Roquefort. ^- The ripening of ex- perimental Roquefort has required four to six months at a relative humidity of 85 to 90 per cent. This relative humidity is just below the equilibrium relative humidity of the cheese, hence permits a shrinkage of 2 to 4 per cent in the water-content of the cheese. This makes it possible to control the amount of surface slime developed. If the relative humidity goes too high, the surface slime of bacteria and yeasts becomes very heavy, soft and almost liquid, and follows the openings into the cheese with resultant damage to appearance and flavor. Even under the conditions at Roquefort, this slime must be removed by rubbing or scraping several times to avoid injury to the cheeses, together with the production of bad odor and taste. If the humidity becomes too loW, the surface becomes dry, hard and cracks open, the friable crumbly texture is injured, and there is consider- able loss in weight. Salt forms about 4 per cent of the cheese. This is in solution in the water present, which is about 40 per cent, and' makes a brine of about 10 per cent strength. This strength of brine does not prevent the growi:h of the Roquefort mold (Penicillium Roqueforti) but does hinder the development of Oidium lactis in the ^ Thorn, C, and Currie, J. N., The dominance of Roquefort mold in cheese, Jour. Biol. Chem. 15 (1913), no. 2, pages 247-258. SEMI-HARD CHEESES 157 open spaces within the cheese. Accurate adjustment of temperature and relative humidity in the ripening rooms to salt and water-content in the cheese is essential to proper ripening. These conditions are furnished by the unique natural conditions of the caves of Roquefort. The production of such cheeses elsewhere depends either on the discovery of another locality with closely similar conditions or on the artificial production and control of the necessary temperature and relative humidity. This has been done on an experimental basis by the use of cold storage apparatus combined with proper humidifiers. The differences between working with sheep's and with cow's milk lie in the making process rather than in the ripening. Sheep's milk freshly drawn shows a higher acidity than cow's milk, probably on account of the acid reaction of its greater casein content. With nearly double the total solids of cow's milk, the yield to one hundred pounds is much greater, consequently the drain- age of the curd is much more easily handled. Once made and salted, the cheeses require very nearly the sam.e conditions of ripening. The resultant products are alike in appearance and texture. In flavor, cow's milk Roquefort differs in character from sheep's milk cheese to such a degree as to be recognized by taste. The difference was found by Currie ^ to be due to an actual difference in the combination of fatty acids present. Although these differences in character are recognizable by the expert in testing the cheese, as well as by chemical analysis, cow's milk Roquefort would satisfy that large proportion of consumers who use such cheese only in connection with other fairly high flavored foods. The ^ Currie, J. N., The composition of Roquefort cheese fat. Jour. Agr. Research, 2 (1914), 6, pages 429-434. 158 THE BOOK OF CHEESE demands for technical skill and factory equipment are not naturally greater than for many other lines of cheese- making. The gradual development of a cow's milk Roquefort may be anticipated. 171. Gorgonzola ^ is a rennet cheese made from fresh whole cow's milk, in northern Italy. It takes its name from the village of Gorgonzola, a few miles from Milan, but the manufacture of the cheese has spread Fig. 24. — Gorgouzola ripening establishment in valley near Lecco. over a wide area. The cheeses are made on farms and in factories from which they are transported for ripening to cool valleys of the Alps, principally near Lecco (Fig. 24). Boeggild introduced the making of a cheese after the Gorgonzola process into Denmark about 1885. This industry has been successful on a small scale since that time. Gorgonzola cheeses are about 30 cm. (12 inches) in diameter and 18 cm. (7 inches) thick and weigh 15 to 20 pounds. As exported they are usually heavily ^ Thorn, C, Soft cheese studies in Europe, U. S. Dept. Agr. Bur. An. Ind. Kept. 22, pages 79-109, 1905. SEMI-HARD CHEESES 159 coated ^ with a mixture usually barite, tallow and lard colored with annatto or other chetese color. This coating prevents shrinkage or mold on the surface of the cheese in transit. When cut these cheeses vary greatly. All show marbling with mold (Roquefort mold). During their ripening they become very slimy at the surface. To open up air spaces for mold growth, this slime is scraped off and holes are punched into the cheeses. These holes are readily seen in the final product. Some show crumbly texture, well distributed mold, as in Roquefort, with flavor approaching that cheese ; in others the texture is waxy rather than crumbly, a condition correlated regularly with different character in the flavor. Fre- quently in whole areas or in small pockets, slime consist- ing of bacteria and Oidiiim has followed the openings into the cheese and affects its odor and taste. Experimental Gorgonzola cheeses comparable with the Italian product were made with cow's milk ripened as for Roquefort or higher, to 0.25-0.30 per cent (titrated as lactic acid), curdled at 86° F. (30° C), cut into cubes and slightly stirred, then dipped to a draining board for about one-half hour, and put into the hoop. The cheeses drained quickly to about 50 per cent water and developed a surface rind as in the harder cheeses. Cut surfaces showed a fairly open cheese in which mold grew readily. These cheeses were salted to taste, not to a specified percentage. They ripened with the same irregular results and the characteristic range of flavors found in Gorgonzola. To avoid the rotting of the cheese by sur- iFrestadius, A., Nord. Mejeri Tid. 17 (1912), 14, page 159, Abs. N. Y. Produce Rev. 34 (1912), 2, page 54, and Cutting, W. B., The use of baritine in cheese rinds, Mo. Commerce and Trade Repts. 1908, 337, page 144, also in Practical Dairyman, 2 (1908), 7, page 76. 160 THE BOOK OF CHEESE face growths, they were exposed to low humidities for a time and cracks opened at the surfaces, as seen in the ripening rooms at Lecco (Fig. 24). The texture was more or less waxj^ or tough, which was correlated with the slightly higher heat at jenneting together with the stirring or " working " of the curd. Comparative an- alyses of a series of imported cheeses confirm the inter- pretation that the salt-content of Roquefort, 4 per cent Fig. 25. — Gorgonzola cheese curing-room. approximately, prevents the invasion of the interior of the cheese by Oidium. No complete study of the ripen- ing of Gorgonzola has been made. As far as followed, it consists in an initial souring process followed by ripen- ing by molds and slime organisms. At its best, Gorgon- zola is nearly equal to Roquefort but the percentage of SEMI-HARD CHEESES 161 such quality is low. In spite of its irregular quality, England has used larger amounts of Gorgonzola than of Roquefort. Considerable quantities have been imported for the Italian trade in the United States. 172. Stilton cheese bears the name of an English village ^ in which it was first sold. It is made from cow's milk and is t^^jically a whole milk cheese, although part skim cheeses are regularly made and sold as lower grades. In the Stilton-making counties, the milk from Shorthorn cattle testing about 3.5 to 4.0 per cent fat is preferred to richer or poorer grades. Such milk is curdled with rennet at about 86° F. in about one hour ; the curd is cut, dipped to a draining table covered with cloth and drained slow^ly over a period of several hours, commonly overnight. During this period considerable acidity is developed. The curd is then milled or broken by hand, salted, packed into hoops 15 to 16 inches high and 7 inches in diameter. These hoops are made from heavy tin (Fig. 26) with four rows of holes about to' inch in diameter. The freshly filled hoops are allowed to stand and drain without pressure, in a room at about 70° F. (Fig. 26). Such cheeses are turned every day for several days. When solid enough to stand the hoops are removed, the cheeses are scraped or rubbed wdth a knife until the surface is smooth, and commonly wrapped with a cloth bandage to maintain the shape, if the cheese is still too soft to stand firmly. In the factories, several rooms are used with varying temperature and relative humidities, which makes it possible to place each ^ Stilton Cheese — J. P. Sheldon — from abs. by New York Produce Rev. 28 (June 16, 1909), no. 8, pages 362-363. Stilton is said to have originated with Mrs. Paulet, Wymondliam, Co. of Leicester, and to have been sold by her brother — Host of the "Bill" at Stilton from which village it derived its name. 162 THE BOOK OF CHEESE cheese under the condition best suited to its texture and condition of ripeness. In general, the dairy sections of England are much more humid than those of America and there are less violent changes in temperature. Stilton Fig. 26. — Stilton cheeses in hoops, draining. cheese-making has grown up to take advantage of this climatic factor in handling the product. Transplanta- tion of such an industry necessitates a mastery not only of the manipulations but a grasp of the fundamental principles underlying the process and a readjustment of practices to preser\'e those principles. SEMI-HARD CHEESES 163 Stilton is, then, a soured curd cheese in whose ripening a very prominent part is played by the green mold (usu- ally some strain of P. Roqueforti) which grows throughout the cavities of its mass.^ At its best, it has attractive texture and flavor. Much of it fails to reach high quality on account of the invasion of bacteria, Oidium lactis, and very frequently myriads of cheese mites. The following analysis was furnished as typical for ripe cheese by Miles Benson,^ late professor of dairying at Reading, England : Water 31 per cent, fat 36 per cent, casein 29 per cent, mineral constituents including salt about 4 per cent. Approximately the same figures are given by Primrose McConnell (Agricultural Note Book). The low percentage of salt is another factor of uncertainty in the control of this Stilton product, as in Gorgon- zola, since these cheeses are commonly high in water- content at first and are thus subject to invasion by Oidium. Stilton has been made on a small scale in Canada ^ and occasionally attempted in the United States. No serious effort to develop an industry of commercial im- portance has been made in America. Comparative study of the cheeses ripened by green mold tends to the con- viction that the adaptation of the Roquefort practice to the use of cow's milk offers a more satisfactory basis for experiment than efforts to establish a Stilton or a Gorgon- zola industry. ^ Pereival, J., and G. Heather Mason, The microflora of Stil- ton cheese, Jour. Agr. Sci. 5 (1913), part 2, pages 222-229. See also Thorn, C, Soft cheese studies in Europe, U. S. Dept. Agr. Bur. An. Ind. Kept. 22 (1905), pages 79-109. ^ Benson, Miles, in personal letter from analyses of cheeses selected for the purpose. ^ Dean, H. H., The Creamery Journal, Nov. 1904. 164 THE BOOK OF CHEESE 173. Gex. — A cheese under this name made in southern France resembles, in its general character as a ripened cheese, the English Stilton and Italian Gorgonzola. Al- though it has no commercial importance, reference is made to this cheese to show that mold-ripened cheeses have been developed entirely independently in different countries to bring about the same general character of product. 174. Bacterially ripened series. — The semi-hard cheeses ripened by bacteria stand half-way between true Lim- burger and the hard forms. In fact, brands of Lim- burger are readily found which approach the texture and ripening of Brick cheese. In the same way, Brick cheeses are often found which have the appearance, texture and much of the flavor of the Cheddars with only a trace of the taste of Limburger. Port du Salut, Oka, Miinster, in France Livarot, in the Balkan regions Kascoval, belong in this series. 175. Brick cheese. — The name of this cheese is probably due to the finished product being about the size and shape of a brick. It is similar to the German cheese Biickstein and may have been developed from it. It is typically a sweet-curd cheese, made from milk freshly drawn, without permitting the development of appre- ciable quantities of acidity until after the curd has been put into the hoop. In the making process, it is inter- mediate between Limburger and the cheeses of the Cheddar group. Some cheese-makers use an ordinary cheese vat, others a copper kettle in manufacturing. It is the usual practice to deliver the milk to the cheese factory both morning and evening, without cooling. Cheese is made twice a day. In some cases the milk is delivered only once a day, and extra precautions must then be taken to care for the milk properly. SEMI-HARD CHEESES 165 The discussion of the care of milk in Chapter II appHes to that for Brick cheese. For the best quality of cheese, the milk in the vat should show about 0.15 of 1 per cent acidity and never above 0.18 of 1 per cent.^ 176. Making of Brick cheese.^ — The milk is received at the cheese factory at a temperature of about 92° to 96° F. For the best results, the acidity should be deter- mined (by the acid test) to decide on the amount of starter to use. Few Brick cheese-makers use an acid test or a starter but these precautions would improve the product of many factories. For method of using the acid test, see Chapter V. Chapter IV discusses the prepa- ration and use of starter. Usually 0.25 to 0.50 of 1 per cent of starter is the amount required. A small amount of starter is used to aid the development of lactic acid and for the beneficial efl'ect it has on the flavor. A very small development of acid is desired after adding the starter ; therefore the change in acidity should be very carefully watched with the acid test. The vat is usually set when the acid test shows 0.16 of 1 per cent acidity. The more acid in the milk, the less starter should be employed. Sufficient rennet extract should be used to give a coagulation suitable for cutting in thirty to thirty-five minutes. For method of adding the rennet extract, see Chapter V. When the coagulum is firm 1 N. Y. Produce Rev. etc., Vol. 32, no. 14, page 536. 2 N. Y. Produce Rev. etc., Vol. 30, no. 5, page 188; Vol. 30, no. 14, page 534 ; Vol. 31, no. 5, page 182. Marty, G., Brick cheesemaking, Wis. Cheese-makers Assoc, 15tli Annual Meeting, 1907, page 66. Wuethrieh, F., The manufacture of Brick cheese, Wis. Cheese- makers Assoc, 14th Annual Meeting, 1906, page 50. Schenk, C, Brick cheesemaking. Wis. Cheese-makers Assoc, 13th Annual Meeting, 1905, page 38. 166 THE BOOK OF CHEESE enough for the curd to break clean over the finger, it is ready to cut. The curd is cut with coarse knives into f- or ^inch cubes. After cutting, the curd is let stand three to five minutes, then stirred with the hands for a few minutes until the whey begins to separate and then stirred with the rake. Some makers do not stir by hand but use the rake directly after cutting. When this is done, great care must be exercised to stir the curd with- out breaking up the pieces, because this causes a loss of fat. After cutting the curd is stirred for twenty to thirty minutes before the steam is turned on. The curd is heated very slowly at first and more rapidly during the last stages of cooking. The curd is cooked to a tempera- ture of 110° to 115° F. The lower the temperature that can be used to produce firm curd, the better the texture of the eheese. After cutting and during the cooking, the curd must be constantly stirred so that lumps will not form. When the curd forms lumps, the moisture is not evenly expelled. This results in uneven texture and curing. Sometimes some salt is added to the curd in the vat to restrain souring. The curd is stirred after cooking until it is sufficiently firm. It remains usually in the whey for a total period of one and one-fourth to one and one-half hours from the time of cutting. It is* then dipped into forms 10 inches long by 5 inches wide by 8 inches deep. The forms are without top or bottom and are placed on a draining table. This table is so constructed that the whey can be saved for stock feed. When ready to " dip," the whey is drawn down to the surface of the curd in the vat, then the curd is dipped into the forms or hoops. Care must be taken to get the same amount of curd into each form to produce the cheeses of uniform size. Each cheese is turned several times SEMI-HARD CHEESES 167 to insure even draining and even reduction of the temper- ature. While draining, a follower is placed in each hoop and a weight placed on each cheese. Usually a brick is used for this weight. A cheese is allowed to drain or press for ten to fifteen hours. It is then placed on the salting table and rubbed with coarse salt. While on the salting table, a cheese is placed on its broad side. Some cheese-makers prefer to salt their cheeses by soaking them in a salt brine. This brine should be strong enough to float an egg. Salting requires three days. The cheeses are then brushed free from excess salt and taken to the cellar to cure or ripen. 177. Ripening Brick cheese. — For this process, the cellars are kept at about 90 per cent relative humidity and a temperature of (30° to 65° F. Some prefer a tempera- ture for curing as high as 68° F. During the curing, the surfaces of the cheese are kept moist and mold growths kept down by rubbing or brushing the cheese with pure water or salt and water. In the curing cellars the cheeses are placed on shelves ; at first they are set close together and as they cure, they are separated. During curing, the color changes from a whitish to a reddish brown. The cheese cures from the outside toward the center. When first made, the product is harsh and hard in texture but during the ripening process it becomes mellow and smooth. The cheeses remain on the curing shelves for four to six weeks, after which they are wrapped in heavy waxed paper and boxed. A cheese ready for market usually weighs about five pounds. A Brick cheese box is 5 inches deep by 20 inches wide by 3 feet long, and holds 110 to 115 pounds of cheese. 178. Qualities of Brick cheese. — The cheeses should be neat and attractive and the rind not cracked or broken. 168 THE BOOK OF CHEESE The sides should be square and not bulged. The cheese should have a clean, characteristic Brick cheese flavor. The body and texture should be mellow and smooth and when rubbed between the thumb and forefinger, should break down like cold butter. The color should be uni- form. The cheese should contain the proper amount of salt and moisture. One of the worst faults with Brick cheese is bad flavor. This is many times due to the cheese-maker not using clean flavored starter. It may also be due to bad flavored milk. A Brick cheese-maker has no means of controlling gassy fermentations. These show themselves in the bad flavor of the cheese and in the porous body. They also cause the cheese to bulge. If detected, gassy milk should be rejected. If too much acid is developed, a sour cheese is the result. This will not cure normally and usually has a sour flavor. The body will be brittle and mealy. If too much salt is used, the cheese may have a salty taste and it will cure very slowly. If not enough salt is used, the cheese may cure too rapidly and vmdesirable flavors and fermentations develop. The cheese must have the proper moisture- content ; if too much moisture is present, the cheese cures too fast and is soft and pasty in body ; if not enough moisture, then the reverse is true. Tabulation of cheeses of special quality, as submitted in scoring contests, show an average water-content of 37 to 38 per cent, with occasional cheeses verging toward Limburger in texture and flavor with 40 to 42 per cent water, and others in- distinguishable from Cheddar, with water-content as low as 34 per cent. The Wisconsin Cheese-makers Association uses the following score-card for the judging of Brick cheese on a scale of 100 : SEMI -HARD CHEESES 169 Flavor 40 Texture 40 Color 10 Salt 5 Style _5^ 100 179. Composition and 3deld. — The composition of Brick cheese varies within wide limits. The average cheese probabl}' contains from 37 to 39 per cent of water, although many cheeses are above and below this average ; Doane and Lawson ^ give the fat as 28.86 per cent, pro- teins 23.8 per cent and total ash 4.20 per cent. The composition and yield are both affected by : (1) the moisture-content of the cheese ; (2) composition of the milk from which made ; and (3) losses during the manu- facturing process. The a^•erage yield of Brick cheese is 11 to 13 pounds to 100 pounds of milk. 180. Port du Salut cheese. — The Trappist monks originated this type of cheese in their monasteries in France. Under the name of their community Oka, it has been made and sold widely by the Trappist Fathers of Quebec. In recent years, factories independent of the order have made such cheese both in America and in Europe. The following outline of the making process indicates the close relationship between Port du Salut and Brick cheeses. Whole milk or milk not over one-fifth skimmed is ripened to medium acidity, then heated to 90° to 95° F. according to season and acidity. Rennet enough is ' Doane, C. F., and H. W. Lawson, Varieties of cheese, de- scriptions and analysis, U. S. Dept. Agr. Bur. of An. Ind. Bui. 146, 1911. 170 THE BOOK OF CHEESE added (see Chapter V) to curdle in thirty to forty min- utes, although some makers shorten the time to twenty minutes. When formed, the curd is cut into small cubes and excess of whey is dipped away. The constantly stirred mass is then heated or cooked to 100 to 105 F. within a period of ten to twelve minutes or according to some makers twenty to thirty minutes. It is allowed to stand a few minutes to settle. Most of the whey is then drawn and the mass is stirred vigorously to prevent fusion of the curd granules. The curd is ready for the hoop when the particles are about the size of grains of wheat and do not stick together when squeezed w^ith the hand. The individual grains of curd should crumble easily between the fingers. The hot curd is transferred directly to the hoops without cooling. For this purpose, a hoop is set upon the table covered with a cloth and the curd dipped into the cloth. The edges of the cloth are then folded over. In this condition the cheese is trans- ferred to the press where gradually increasing pressure begins with 3 to 4 pounds and reaches about 70 pounds. To insure proper shape, cheeses are turned and put into fresh cloths at the end of the first hour and turned subse- quently several times during the pressing period of about twelve hours. ^ Port du Salut cheeses are salted by rubbing fine salt on the surface by hand at the rate of 1.2 to 2 per cent of the weight of the cheese. After about two days in the salting process, they are put into the ripening cellars. The cellars are wet, since they reach 90 to 95 per cent relative humidity at a temperature of about 55° F. After two days in the cellar, the cheeses are plunged ^ Ligeon, X., Herstellung des Port Salut Kases, Milchztg. 38 (1909), no. 39, pages 459-460. SEMI-HARD CHEESES 171 into a tank of saturated brine to which a trace of cheese color has been added. As they come out of these tanks, they are yellowish and greasy or slimy. They are re- turned to the shelves where they are rubbed every day with a cloth or by hands wet in brine. After about one week they are again plunged in the brine. Treatment with brine tends to insure a firm rind. The cheeses are rubbed more or less regularly with brine through the whole ripening period. After six weeks, such cheese may be eaten. The cut surface of Port du Salut is creamy in color, may or may not show small holes. In texture it is soft enough to spread readily under pressure without losing its shape in handling. In flavor the cheese is a mild form belong- ing to the Limburger group. Port du Salut cheeses as imported from France usually are firm round cakes about 1^ inches thick, weighing about 3 pounds. CHAPTER XI THE HARD CHEESES The hard cheeses form a great series of groups, whose most prominent physical character is their firm or hard texture. This is correlated with comparatively low water-content; which is usually between 30 and 40 per cent. Although certain \arieties occasionally test above 40 per cent water, this deviation is accompanied by quick ri])ening and rapid sjioilage. These varieties of cheese are staple products with long marketable periods; therefore they may be handled in large lots, shipped, carted and stored freely without the losses such treat- ment would entail in soft cheese. The retailer frequently buys hard cheese by the ton, not by the cheese or by the box. In making, these varieties are characterized as cooked and pressed cheeses. Although both the heating of a curd and the pressing of a newly made cheese occur among semi-hard forms, these practices appear in their most typical forms in the hard cheeses. The hard cheeses show two types of texture. A cut cheese may appear smooth, free from holes or with a few angular cracks or seams, or it may show round holes or "eyes." In the smooth textured forms every effort is made to prevent gassy fermentations, usually by control- ling the fermentation of the curd in the making process. 172 THE HARD CHEESES 173 When " eyes " are present, the end sought has been a development of a particular form of gassy fermentation which gives this api)earance and brings about the char- acteristic ripening texture and flavor. The hard cheeses have been developed in groups of national varieties. The best known of these groups are those which may be represented by English Cheddar, American Factory Cheddar, Danish, the Edam of Hol- land, Swiss and Parmesan with many related varieties in Italy and neighboring countries of southern Europe. 181. The Danish group. — The Danish cheeses are related in appearance and flavor to the English group represented by Cheddar. The demand for butter in Europe has been so great that the Danish cheese-makers have developed skim and part skim \'arieties largely to the exclusion of the whole milk form. Skillful handling of their process has resulted in a product which has had a very large and appreciative market in England and Germany. 182. The Dutch group. — Edam and Gouda are the two forms of cheese made in Holland and most widely known among other peoples. Both reach America in con- siderable quantities; both are shipped in large amounts to tropical countries. Although attempts have been made to manufacture them in America, no commercial production of these cheeses has been successful. Al- though whole milk grades of these cheeses are known, they are to a large measure part skim in manufacture. The presence of one or both of these forms in every large market in America makes the general facts of their produc- tion of general interest. Parts of a report on experimental work in the making of Edam and Gouda are, therefore, given here. 174 THE BOOK OF CHEESE 183. Edam cheese ^ is a sweet-curd type, made from partially skimmed -milk. It comes to the market in the form of round red balls, each weighing from 3^ to 4 pounds when cured. It is largely manufactured in northern Holland and derives its name from a town famous as a market for this kind of cheese.^ Milk from which one-fourth to one-third of the fat has been re- moved is used. Too great pains cannot be taken in regard to the condition of the milk. It should be fresh, free from every trace of taint ; in brief, it should be in as perfect condition as possible. 184. Method of manufacture. — The following para- graphs give the steps in the manufacture of Edam cheese : Treatment of milk' before adding rennet. — The tempera- ture of the milk should be brought up to a point not below 85° F. nor much above 88° F. When the desired temperature has become constant, the coloring matter should be added. Cheese color is used at the rate of l| to 2 ounces for 1000 pounds of milk. The coloring matter should, of course, be added to the milk and thoroughly incorporated by stirring before the rennet is added. Additimi of rennet to milk. — The rennet should not be added until the milk has reached the desired temperature (85° to 88° F.) and this temperature has become constant. ^ These paragraphs were taken from N. Y. Exp. Sta. Bui. 56, Experiments in the manufacture of cheese ; Part I. The manu- facture of Edam cheese, 1893. See also, Haeeker, T. L., Experi- ments in the manufacture of cheese, Minn. Exp. Sta. Bui. 35, 1894. 2 Boekhout, F. W. J., and J. J. O. de Vries, Cracking of Edam, Verslag. Landbouwk. Onderzoek. Rykslandboupoefstat. (Nether- lands), 20 (1917), pages 71-78, fig. 1. Boekhout, F. W. F., and J. J. O. de Vries, Sur le defaut "Knijpers" dans le fromage d'Edam, Rev. Gen. Lait, 9 (1913), no. 18, pages 420-427. THE HARD CHEESES 175 When the temperature reaches the desired point and re- mains there stationary, the rennet extract is added. Rennet extract may be used, 4^ to 5^ ounces being taken for 1000 pounds of milk, or enough to coagulate the milk in the desired time, at the actual temperature used. The milk should be completely coagulated, ready for cutting, in about twelve to eighteen minutes from the time the rennet is added. The same precaution observed in making Cheddar cheese should be followed in making Edam cheese with reference to care in adding the rennet, such as careful, accurate measurement, dilution with pure water before addition to milk. Cutting the curd for Edam. — When the curd breaks clean across the finger, it should be cut ; it is cut a very little softer than in the Cheddar process as ordinarily prac- ticed. As stated, this stage of hardness in the curd which fits it for cutting should come in twelve to eighteen min- utes after the remiet is added. First, a vertical knife is used and the curd is cut lengthwise, after which it is allowed to stand until the slices of curd begin to show the separation of whey. Then the vertical knife is used in cutting crosswise, after which the horizontal knife is at once used. Any curd adhering to the bottom and sides of the vat is carefully removed by the hand, after which the curd-knife is again passed through the mass of curd lengthwise and crosswise, continuing the cutting until the curd has been cut as uniformly as possible into very small pieces. Treatment of Edam curd after cutting. — When the cutting is completed, one commences at once to heat the curd up to the temperature of 93° to 96° F. The heating is done as quickly as possible. While the heating is in progress, the curd is kept constantly agitated to prevent settling 176 THE BOOK OF CHEESE and consequent overheating. As soon as the curd shows signs of hardening, which the experience of the worker will enable him to determine, the whey is drawn off until the upper surface of the curd appears, when one should commence to fill the press molds. Filling molds, pressing and dressing Edam. — The molds, which are described later in detail, are well soaked in warm water previous to use, in order to prevent too sudden chilling of curd and consequent checking of sepa- ration of whey. As soon as whey is drawn off, as indi- cated above, one begins to fill the pressing molds (Fig. 27). The filling should be done as rapidly as possible to prevent too great cooling of curd, ^^^len the curd has been put into the molds, its temperature should not be below 88° F. Unless care is taken to keep the curd covered, the portion that is last put into the molds may be- come too much cooled. In making Edam Fig. 27. — Edam cheese ou a small scale, it is a good plan to squeeze the moisture out with the hands as much as possible and then break it up again before put- ting in the molds, when the curd should be pressed into the mold firmly by the hands. The molds should be filled as nearly alike as possible. The cheese should weigh from 5 to 5j pounds each when ready for the press. When the filling of molds is completed, they are put under continual pressure of 20 to 25 pounds for about twenty-five or thirty minutes. AYhile the cheese is being pressed, some sweet whey is heated to a temperature of 125° or 130° F., and this whey should not be allowed to go below 120° F. at any time while it is being used. When the cheeses are taken from their molds, each is put into the warm whey for two minutes, then removed and dressed. For dress- THE HARD CHEESES 177 ing Edam cheese, the ordinary cheese bandage cloth is used. This is cut into strips, which should be long enough to reach entirely around the cheese and overlap an inch or so, and which should be wide enough to cover all but a small portion of the ends of the cheese when put in place. Before putting on the bandage, all rough pro- jections should be carefully pared from the cheese. In putting on, the cheese is held in one hand and the bandage is wrapped carefully around the cheese, so that the whole is covered, except a small portion on the upper and lower surface of the cheese. These bare spots are covered by small pieces of bandage cloth of a size sufficient to fill the bare surface. The bandage is kept wet with the warm sweet whey, thus facilitating the process of dressing. After each cheese is dressed, it should be replaced in the dressing mold, care being taken that the bandage remains in place and leaves no portion of the surface of the cheese uncovered and in direct contact with the mold. The cheese is then put under continual pressure of 60 to 120 pounds and kept for six to twelve hours. 185. Salting and curing Edam. — There are two methods which may be employed in salting, — dry and wet. In dry-salting, when the cheese is finally taken from the press, it is removed from the press mold, its bandage is removed completely, and the cheese placed in another mold, quite similar, known as the salting mold. Each cheese is placed in a salting mold with a coating of fine salt completely surrounding it. The cheese is salted in this way once each day for five or six days. Each day the cheese should be turned when it is replaced in the mold, so that it will not be rounded on one end more than the other. In the method of wet-salting, the cheese is placed in a 178 THE BOOK OF CHEESE tank of salt brine, made by dissolving common salt in water in the proportion of about 1 pound of salt to 22 quarts of water. Each cheese is turned once a day and should be left in the brine seven or eight days. When the cheese is taken from the salting mold or salt bath, it is placed in warm water and given a vigorous, thorough brushing in order to remove all slimy or greasy substances that may have accumulated on the outer surface. When the surface is well cleansed, the cheese is carefully wiped dry with a linen towel and placed upon a shelf in the cur- ing-room. In being put on the shelves, the cheeses should be placed in contact so as to support one another, until they have flattened out at both ends so much that they can stand upright alone. Then they are moved far enough apart to allow a little air space between them. Another method of securing the flattened ends is to sup- port each cheese on opposite sides by wedge-shaped pieces of wood. After being placed on the sheh-es in the curing- room, they are turned once a day and rubbed with the bare hand during the first month, twice a week during the second month and once a week after that. When any slimy substance appears on the surface of the cheese, it should be washed off at once with warm water or sweet w^hey. The special conditions of the curing-room will be noticed in detail below. W'hen the cheeses are about two months old, they can be prepared for market in the following manner : They are first made smooth on the surface by being turned in a lathe or in some other manner, after which the surface is colored. For coloring, some carmine is dissolved in alcohol or ammonia to secure the proper shade, and in this color-bath the cheeses are placed for about one minute, when the}' are removed and allowed to drain, and as soon as they are dry the outside of each THE HARD CHEESES 179 cheese is rubbed with boiled hnseed oil, in order to pre- vent checking. They are then wrapped in tin-foil, which is done very much like the bandaging. Care must be taken to put on the tin-foil so that it presents a smooth, neat appearance. The cheeses are finally packed in boxes, containing twelve cheeses in each box, arranged in two layers of six each with a separate partition for each cheese. 186. Equipment for making Edam cheese. — Careful attention must be given to the moisture and temperature of the curing-room. This room should be well venti- lated,, quite moist and its temperature kept between 50° and 65° F. These are conditions not easy to secure in any ordinary room. Some form of cellar is best adapted for these conditions. The amount of moisture can be determined by an instrument known as a hygrometer. In a curing-room suited for Edam cheese, the moisture should be between 85 and 95 per cent, or a little short of saturation. When the temperature is between 50° and 65° F., the moisture is between 85 and 95 per cent if the wet-bulb thermometer is from 1 to 2° F. (or ^ to 1° C.) below the dry-bulb thermometer. Cheese will check or crack and be spoiled for market, if the degree of moisture is not kept high enough. Aside from the molds, press and salting vat, the same apparatus that is used in making Cheddar can be used for Edam cheese. The pressing mold is turned preferably from white wood or, in any case, from wood that will not taint. Each mold consists of two parts ; the lower constitutes the main part of the mold, the upper portion is simply a cover. The lower portion or body of the mold has several holes in the bottom, from which the whey flows when the cheese is pressed. Care must be taken 180 THE BOOK OF CHEESE to prevent these holes being stopped up by curd. This part of the mold is about six inches deep and six inches in diameter across the top. The salting mold has no cover and the bottom is provided with onl}^ one hole for the out-flow of whey ; in other respects it is much like the pressing mold. 187. Qualities and yield of Edam cheese. — The flavor of a perfect Edam cheese is difficult to describe. It is mild, clean, and pleasantly saline. In imperfect Edams, the flavor is more or less sour and offensive. In body, a perfect Edam cheese is solid, rather dry and mealy or crumbly. In texture, it should be close and free from pores. In the experiments here reported the amount of fat in 100 pounds of the partially skimmed-milk varied from 2.45 to 3.20 pounds and averaged 2.77 pounds. Of this amount, from 0.30 to 0.51 pound of fat was lost in the whey, with an average of 0.39 pound. The yield of cheese from 100 pounds of milk varied from 9.60 to 11.82 pounds and averaged 10.56 pounds. 188. Gouda cheese. ^ — This Dutch variety is a sweet- curd cheese made from whole milk. In shape, the Gouda cheese is somewhat like a Cheddar with the sharp edges rounded off and sloping toward the outer circumference at the middle from the end faces. They usually weigh 10 or 12 pounds, though they vary in weight from 8 to 16 pounds. They are largely manufactured in southern ^ Paragraphs taken from N. Y. Exp. Sta. Bui. 56, Experi- ments in the manufacture of cheese ; Part II. The manufacture of Gouda cheese, 1893. See also, Hayward, H., Method of making Gouda cheese. Pa. Exp. Sta. Rept. 1890, pages 79-81, and Haecker, T. L., Experiments in the manufacture of cheese, Minn. Exp. Sta. Bui. 35, 1894, and Monrad, J. H., in N. Y. Produce Rev. 25 (1907), no. 8, page 330, where a home process of making this cheese is given. THE HARD CHEESES 181 Holland, and derive their name from the town in which they were first made. Fresh sw^eet milk that has been produced and cared for in the best possible manner should be used. 189. Method of manufacture. — The processes of manufacturing Gouda cheese are as follows : Treatment of milk before adding rennet. — The tempera- ture of the milk should be brought up to a point not below 88° F. nor much above 90° F. When the desired tempera- ture has been reached and has become constant, the color- ing matter is added. One ounce of cheese color for about 1200 pounds of milk may be used. The coloring matter should be thoroughly incorporated by stirring before the rennet is added. Addition of rennet to milk. — The rennet should not be added until the milk has reached the desired tempera- ture (88 to 90° F.) and this temperature has become con- stant. The milk should be completely coagulated, ready for cutting, in fifteen or twenty minutes. The same precautions should be used in adding rennet as those previously mentioned in connection with the manufac- ture of Edam cheese. Cutting the curd. — The curd should be cut when it is of about the hardness generally observed for cutting in the Cheddar process. The cutting is done as in the Ched- dar process except that the curd is cut a little finer in the Gouda cheese. Curd should be about the size of peas or wheat kernels when ready for press and as uniform in size as possible. Treatment of curd after cntting. — After the cutting is completed, heating and stirring is begun at once. The heating and constant stirring is continued until the curd reaches a temperature of 104° F., which should require 182 THE BOOK OF CHEESE from thirty to forty minutes. When the curd becomes rubber-Hke in feehng, the whey should be run off. The whey should be entirely sweet when it is removed. Pressing and dressing Goudo. — After the whey is off, the curd is put in molds at once without salting (Fig. 28). Pains should be taken in this process to keep the temperature of the curd as near 100° F. as possible. Each cheese is placed under continuous pressure amount- ing to ten or twenty times its own weight and kept for about half an hour. The first bandage is put on in very much the same manner as in Edam cheese making. The cheese is then put in press again for about one hour. The first bandage is then taken off and a second one like the first put on with great care, taking pains to make the bandage smooth, capping the ends as before. The cheese is then put in press again and left twelve hours or more. Salting and curing. • — When Gouda Fig. 28. — Gouda cheese is taken from the press, the band- cheese mold. . , 1 • • 1 1 p age IS removed and it is placed tor twenty-four hours in a curing-room like that used for Edam cheese, as previously described. Each cheese is then rubbed all over with dry salt until the salt begins to dissolve, and this same treatment is continued twice a day for ten days. At the end of that time, each cheese is carefully and thoroughly washed in warm water and dried with a clean linen towel. The cheeses are then placed on the shelves of the curing-room, turned once a day and rubbed. The temperature and moisture are con- trolled as described in the curing process of Edam cheese. If the outer surfaces of the cheese become slimy at any time, they are carefully washed in warm water THE HARD CHEESES 183 and dried with clean towels. Under these conditions, cheese ripens in two or three months. 190. Equipment for Gouda Cheese. — The molds, press and curing-room are the only equipment' needed in the making of Gouda cheese that differ from that employed in making Cheddar cheese. The mold used for Gouda cheese consists of two portions, which are shown sepa- rately in Fig. 28. These molds are made of heavy pressed tin. The inside diameter at the middle is about 10 inches, that of the ends about 6^ inches. The height of the mold is about 5^ inches, and this represents the thickness of the cheese, but by pushing the upper down into the lower portion, the thickness can be decreased as desired. 191. Composition and yield of Gouda. — In work with milk averaging 4.2 per cent of fat there were lost in the whey from 0.29 to 0.43 per cent with an average of 0.35 per cent of fat. The loss of fat appears to be not much greater than the average loss met with in cheese factories in making Cheddar cheese. From 100 pounds of milk, there were made from 11.60 to 13.35 pounds of green cheese, with an average of 12.50 pounds. The per- centage of water in the experimental cheese varied from 41.25 to 45.43 per cent and averaged 43.50 per cent. CHAPTER XII CHEDDAR CHEESE-MAKING Cheddar is the best known cheese tliroughout the United States and the one most commonly made in factories. The Cheddar process was brought to America by EngHsh immigrants. Similar to Cheddar cheese are Pineapple, English Dairy, Sage cheese, skimmed-milk and California Jack cheese made in this country, and Derbyshire, Leicestershire, Wensleydale and Cheshire made in England. The Cheddar cheese process as employed in the factories to-day has been modified and improved since it was first introduced into this country by the early immigrants. The following description^ includes only the practices as found in the factories to-day if whole milk is used. Skimmed-milk Cheddar cheese is discussed later. 192. The lot-card. — The Cheddar process involves several hours of manipulation and includes many details which should be closely and accurately observed and recorded. The necessity of carrying observations of several different factors at the same time makes a scheme of recording data essential to convenient work. For this purpose, a lot-card for Cheddar cheese is introduced here and the pages given to particular factors are in- dicated in the space intended for the recording of observa- ^ The authors acknowledge here the helpful suggestions and criticisms of G. C. Button, New York State Cheese Instructor. 184 CHEDDAR CHEESE-MAKING 185 186 THE, BOOK OF CHEESE tions. The manufacture of Cheddar cheese is a compli- cated process, because several factors must be given attention at the same time. A careful record of the observations of each step in the successive handling of each lot of milk puts the operator in possession of a per- manent record of his experience. This record has several uses. It may help to convince patrons of the importance of eliminating faults in the milk ; it furnishes the cheese- maker a cumulative record of his experiences in handling milk with special qualities, such as high or low fat-content, over-acidity or taints. Since Cheddar ripening covers a period of weeks and months, no operator can remember particular lots of milk sufficiently well to be able to use his experience on the interpretation of the qualities foinid in the ripened product. 193. The milk. — It is the usual practice to deliver the milk to the cheese factory each morning (Fig. 29). The night's milk is cooled and kept clean and cold until de- livered at the factory. It is advisable not to mix the cold night's milk and the warm morning's milk, but to deliver them in separate cans to the cheese factory at the same time. The milk is weighed, sample for fat test taken and then run into the vat (Fig. 30). The receiving or taking in of the milk is one of the most important parts of the cheese factory work. It is practically as important as the actual manufacturing of the cheese. Any milk high in acid or with a bad flavor should be avoided. It is often bad policy to reject the milk, for a neighboring factory will accept it and the factory not only loses the milk but also the patron. Factories should have an agreement to prevent this. The acidity can be determined by the acid test, but the detection of flavors must be made by the cheese-maker himself with the aid CHEDDAR CHEESE-MAKING 187 21 CHEESE. This card must remain with lot from the millt room until the finished product is ready to leave the building, then it should be handed to instructor. MAKING Day and Date Vat Milk Used Milk Odor Taste Total pounds Weather conditions % fat lbs lbs. -lbs. fat 8. n. f. casein. Starter Kind used _ % casein Acidity Amount used % used Time of adding starter.... \ adding rennet .... \ coagulation cutting turn'g on steam, turn'g oflF steam dipping packing milling salting hooping • pressing dressing Minutes Total time from 1 setting to pressing J % Acid In Milk when received Temperature of milk when received when starter added.... when rennet added .... when whey removed... at pressing before adding starter after adding starter when rennet added Rennet Test In Whey after curd is cut when milk received.... after adding starter.... at dipping Hot Iron Test at dipping. _ at packing . . at packing at salting at milling.. at salting Condition of Curd when cut when packed .. when milled ... when salted .... when pressed. Amount per 1000 lbs. milk.. Total Amount Color Rennet Salt % fat in ..whey Assisted by lbs. fat esti- mated so lost. % of total milk ..fat lost in whey If comments are added on reverse side, put cross here Work and Observations by YIELD Day and Date Weight of cheese when removed from press to curing room, lbs. milk for Kind of cheese made one lb. cheese. lbs. cheese for one No. of cheese made. lb. fat in milk. If comments are added on reverse side put cross here..._ Work and observations by — Time Serial lbs. No lbs. cheese per 100 lbs. milk lbs. cheese for one lb. total solid Arranged by W. W. Hall. 188 THE BOOK OF CHEESE CHEDDAR CHEESE-MAKING 189 of smell and taste. Many of the bad flavors in the cheese can be traced to the poor quality of the milk. One of the worst qualities in milk and cheese is the presence of gas-producing organisms.^ Any milk which shows gassy fermentation should be rejected, for it is difficult to make cheese from this and at best there will be a large loss during the manufacturing process. The cheese may have a bad flavor and develop " pin-holes " and in extreme cases may puft' up like a ball. The person receiving the milk shovild talk to the farmers or dairy-men about the proper care of the utensils and milk. He must see that the cans are kept clean. One very bad practice is to deliver milk and take home whey in the same cans. The cans, as they are brought back from the cheese factory full of whey, are often left in the barn or near a hog-pen until the whey is fed. Unless such cans are emptied immediately on returning to the farm and then rinsed out with cold water, thoroughly washed and scalded, bad flavors may develop in the cheese. It is thought that this causes " fruity " or sweet flavor, which resembles that of fruits such as raspberries, strawberries or pineapples. 194. Ripening the milk. — A slight development of acidity is required : («) to obtain the formation of a firm curd ; and (b) to establish immediate dominance of a desirable type of lactic organism which will produce the large amount of acid required later in the cheddaring process. The development of this acidification before the addition of rennet is known as the ripening of the milk. The extent of ripening advised by different ^ Russell, H. L., Cheese as affected by gas-producing bacteria. Wis. Exp. Sta. Rept. 1895, pages 139-146. Marshall, C. E., Gassy curd and cheese, Mich. Exp. Sta. Bui. 183, 1900. 190 THE BOOK OF CHEESE schools of makers has varied from an acidity of 0.20 of 1 per cent or even slightly higher percentage titrated as lactic acid, to about 0.17 of 1 per cent as now preferred by some of the most successful groups of workers. The ripeness of the milk can also be determined by the use of the rennet test. The milk may be ripened by allowing the lactic organisms already present in the milk to develop naturally. This requires considerable time and while the lactic acid-forming bacteria are developing, other and undesirable fermenta- tions may be taking place, so that the good results which should follow the uninterrupted development of the lactic acid-forming organisms are lost. Starter is commonly used to produce the desired ripening of the milk. (For the! preparation of starter see Chapter IV.) Some makers put the starter into the empty vat (Fig. 31) and add the milk as it is received ; others add it to Fig. 31. — Steel cheese vat. the total volume of cold milk and then begin to heat it. Whenever the starter is used, it should be strained to remove lumps. These lumps might cause a mottled color in the cheese. The best practice calls for an acidity or a rennet test of the mixed milk after it has been brought to the setting temperature in the vat. With milk tested at this stage and the volume of milk in the CHEDDAR CHEESE-MAKING 191 vat known, the cheese-maker is able to calculate closely the amount of starter needed. When the quantity of starter to use is in doubt, the amount added should be under rather than over the estimate, since the need of more can be determined by making frequent ren- net and acid tests in a very few minutes without damage to the cheese. If too much starter has been used, acid or sour cheese is usually obtained, with loss in market quality. An over-development of acidity at any stage of the man- ufacturing process affects the flavor, body and texture, color and finish of the cheese. The product is known as a sour cheese, and can usually be identified by its sour taste and smell. A sour cheese while curing will seldom develop a normal Cheddar flavor and the texture will be hard and harsh and very brittle. The body will not be smooth but harsh and grainy. The over-development of acid will show by fading or bleaching the color. A sour cheese usually leaks whey for a few days after being placed on the curing-room shelves. Ripening the milk is one of the most important parts of cheese-making. Proper ripening places the acid fer- mentations under the control of the cheese-maker so that he may know what results will follow his labors. The operator can control the acidity while ripening the milk, but after the rennet is added all control of the acidity is lost. From that time, the moisture must be regulated in proportion to the acidity. Before setting, the milk should be ripened to such a point as to leave at least two and one-half hours from the time that the rennet extract is added until the acid de- velopment has reached the stage at which it is necessary to remove the whey. By the acid test the milk may vary 192 THE BOOK OF CHEESE from 0.16 to 0.18 of 1 per cent, but no definite statement can be given for the rennet test. This can be determined only by comparison from day to day. For opera- tion of rennet test see Chapter V. Dm'ing this period of two and one-half hours, the curd is formed, then cut, and the temperature is raised from 84° or 86° F. (the temperature at which the rennet extract is added) to about 98° to 100° F. The curd must be kept agitated so that the particles will not mat together; this is necessary to obtain sufficient contraction of the particles of curd with the proper reduction of water-content. If the milk becomes too ripe (too sour) before the rennet is added, there will not be sufficient time for these steps to take place naturally. In such cases special means are re- quired to firm the curd. These result in a loss of both quality and quantity of cheese. On the other hand, if the milk is not ripened, but the rennet extract added, regardless of the acid development, one of the important natural forces for expelling the moisture is lost. The time required for the particles of curd to contract is much prolonged, the expulsion of whey is usually inadequate and the curd remains in a soft or wet condition. Using too much starter is almost equally bad, for although it hastens the making process, it produces a soiu" or acid cheese. 195. Setting or coagulating, — The milk for Cheddar cheese-making is heated to 86° to 88° F. or occasionally a slightly lower temperature. This temperature is found by experiment to give the texture of curd most favorable for the desired results. Although some cheese-makers work as low as 84° F., the texture of such curd is too soft and coagulates too slowly. The very slight change of 2 F. produces curd which coagulates more quickly and is tougher and firmer. CHEDDAR CHEESE-MAKING 193 If the cheeses are to be colored, the color should be added after all the starter. It should be thoroughly and evenly mixed with the milk to insure an even color in the cheese. If the color is added before the starter, there are likely to be white specks in the cheese, on account of the coagulated casein in the starter. The amount of color to use depends on the tint desired in the cheese. It varies from i to | ounce to 1000 pounds of milk for a light straw color to 1| to 2 ounces for 1000 pounds of milk for a deep red color. Enough rennet should be used to produce a curd firm enough to cut in twenty-five to thirty-five minutes. The necessary amount will vary with the strength of the rennet extract itself, with the acidity, the temperature, the nature of the lot of milk, and with the individual aims of the maker in which he adjusts the other factors to his preferences as to rapidity of rennet action. With the usual commercial extract, the'needed amount ranges from 2.5 to 4 ounces for 1000 pounds of milk. As for all varieties of cheese, the rennet extract should be diluted in cold water at about one part rennet to forty parts water and thoroughly stirred into the milk. (See Chapter V.) 196. Cutting. — The object of cutting is to obtain an even expulsion of the moisture from the curd. The curd is cut as soon as it becomes firm enough. To determine this, various tests may be used. Some opera- tol-s test it by pressing it away from the side of the vat, considering it ready to cut when it separates cleanly from the metal. The test most commonly used is to insert the index finger obliquely into the curd, then to start to split the curd with the thumb and finally to raise the finger gently ; if ready to cut, the curd will split cleanly 194 THE BOOK OF CHEESE over the finger and clear whey will separate to fill the opened crack. Another arbitrary but more or less satis- factory rule is that the time from adding the rennet until cutting should be two and one-half times that from the addition of rennet until the first sign of coagulation is observed. The condition of the curd itself is the best guide to show when it is ready to cut. The condition of the curd is constantly changing, so that in a large vat, if the cutting is not begun until the curd is in the best condition, by the time the last of the curd is cut it will be too hard or firm. It is better to begin while the curd is a trifle too soft so that the cutting will be taking place while the curd is at the proper stage. At best the last of the curd may become too hard. If too hard, it will break ahead of the knife instead of cut. Breaking causes more fat loss than cutting because there is more surface exposed and hence more fat globules. The softer the curd when cut, the quicker and easier the moisture can be expelled. If the curd is cut when soft, care must be exercised not to stir it too hard immediately after cutting. Soft curd breaks very easily. When the curd is cut soft and then stirred vigorously, there is a larger loss of fat than when the curd becomes hard before it is cut. Two knives are used to cut the curd. (See Fig. 11.) These knives may have either wire or blades for cutting. The space between the wires or blades varies from te^o \ inch. Knives used should have blades or wires close enough together to cut the pieces as small as desired, without a second cutting. When the curd has to be cut a second time it usually results in pieces of uneven sizes, be- cause the pieces already cut cannot be evenly split in two. CHEDDAR CHEESE-MAKING 195 One set of knives has horizontal and the other per- pendicular blades or wires. The curd is cut the long way of the vat with the horizontal knife and lengthwise and crosswise with the perpendicular knife so that the result is small cubes or oblongs of curd. Some cheese-makers prefer to use one knife first and some the other, but the result should be a curd cut into pieces of uniform size. The smaller the particles of curd or cubes are cut, the quicker the curd will firm up or cook. If not cut uniformly, the changes taking place later in the curd particles will not be uniform, — the small pieces will be hard and dry while the large ones will be soft and- mushy. Care should be taken to let the knife cut its way into the curd (Fig. 32). If the knife is pushed into the curd. Fig. 32. — The proper way to put the knife into the curd. it will break it and cause a large loss of fat. The same is true when taking the knives out of the curd. The loss of fat due to cutting is very similar to the loss of sawdust when sawing a board. It may be considered a necessary evil. The loss due to cutting is about 0.3 of 1 per cent of fat in the whey and the loss of casein about 0.1 of 1 per cent in the whey. 197. Heating or " cooking " the curd. — After the curd is cut, the pieces (cubes) rapidly settle to the bottom 196 TUE BOOK OF CHEESE Fig. 33. — Acme curd nikc. of the vat and tend to mat together. To prevent this, the curd must be kept stirred. When stirring first begins, the curd is soft and very readily broken. Some cheese- makers prefer to stir by hand for the first few minutes after cutting, while the curd is soft. The importance of careful handling can hardly be over- emphasized. No matter how well the curd has been cut, if the stirring is performed in a careless manner in the early stages, it will be broken into uneven sized pieces and a considerable loss of fat will result. A wooden hayrake or a INIcPherson curd agitator (Figs. 33, 34) may be used to stir the curd. Me- chanical curd agitators are used in some cheese factories. There are several makes. (See Fig. 35.) These agitators save much hand labor, although some stirring by hand must be done in connec- tion with them. The mechanical agitators do not stir the curd in the corners of the vat ; this must be done with the hand rake. It is the usual practice to stir the curd immediately after cutting for five to ten minutes before the mechanical agitators are used. This is necessary to give the curd a slight chance to firm as the mechanical agitators tend to Fig. 34. — McPherson curd agitator. CHEDDAR CHEESE-MAKING 197 198 THE BOOK OF CHEESE break it up. After cutting, a thin film forms on each piece of curd. This fihn holds the curd particles, especially the fat. Breaking the films on the cubes causes loss of fat. If lumps form at the early stage, by matting of the curd particles, violent stirring is required to separate them. When such lumps are broken up, new cleavage lines are formed with loss of fat, because the original films surrounding the soft curd fuse so firmly that the curd cubes do not separate but actually break. New surfaces are thus formed with consequent fat loss. Rapid shrinkage with expulsion of whey takes place during the first few minutes of gentle agitation. Before any heat is applied to the vat, sufficient whey should have separated or formed to float each piece of curd separately. This will require ten to fifteen minutes from the time of cutting. Thus far the first of three distinct factors which expel the moisture from the curd has been considered : (1) the action of the rennet ; (2) the development of the lactic acid; and (3) the application of heat. These forces must have time to act naturally. If heat is applied too soon after the curd is cut or if the temperature is raised too rapidly, it causes a thick film to form on the pieces of curd which interferes with the escape of the whey. The outside of the curd becomes firm but the inside re- mains very soft. A curd which is cooked on the outside only feels firm when stirred by hand in the whey, but when a handful is squeezed the soft centers are noticed. To firm such curd masses requires violent stirring, which will break the thick tough film. This allows the mois- ture to escape and also increases the fat loss. The rapidity of heating should depend on the condition of the curd and the amount, of acid developed. The heat should keep pace with these. When ready to raise the CHEDDAR CHEESE-MAKING 199 temperature, the least amount of steam possible should be allowed to pass through the valve. This should raise the temperature very gradually. If heat is applied too quickly at first, it will cause the curd to lump. A safe rule is to raise the temperature one degree in the first five minutes after the steam has been turned on. The heating should progress slowly until the whole mass of curd in the vat has reached a temperature of 90° to 92° F. The usual temperature to which the curd is heated or cooked is 98° F. to 100° F. The lower the temperature that can be used and properly firm the curd, the better will be the body of the cheese. If the curd is heated too high, it will become hard, which causes a dry hard "corky" cheese. After this temperature has been reached, there is not such a tendency for the curd particles to stick together nor are they so easily broken in stirring. It should require, under normal conditions, not less than thirty to forty-five minutes, from the time the steam is turned on, to raise temperature of the curd from the setting temperature to that necessary to " firm " the curd. If a shorter time is allowed to raise the temperature, the curd will not have opportunity to contract naturally. The temperature required to expel the moisture properly varies with the percentage of fat in the milk. If rich in fat (4.5 to 5.5 per cent) milk requires a temperature of 98° to 104° F. to firm the curd, while the same result can be accomplished with milk testing 3.0 to 3.5 per cent fat at a temperature of 94° to 96° F. A higher temperature is needed in winter than in summer because the milk is usually richer in fat. In a water- jacketed vat, allowance must always be made for the rise in temperature due to the water surrounding it. The water may be removed if there is danger of the temperature going too high. 200 THE BOOK OF CHEESE However, it is better to gauge the heat so that the water may be left, as this helps to hold the curd at an even temperature, especially in cold weather. In a steam- heated ^•at there is not so much danger of the tempera- ture running up. The stirring must be kept up after the steam has been turned off until the curd has reached such a stage of contraction that it will not readily pack or mat in the bottom of the vat. After the curd reaches this stage it may be allowed to settle to the bottom and stirred only occasionally until it is time to remove the whey. If the cheese room is not warm and there is danger of the curd cooling, a cover should be placed on the vat. The curd should not be allowed to settle for more than fifteen minutes without stirring to keep each piece separate. This is necessary to obtain uniform contraction of all curd masses. 198. Removing the whey. — To permit the normal changes in the curd to take place naturally, two and one- half hours from the time the rennet extract is added is ordinarily required before the whey is drawn. The time of removing the whey is determined by two factors : one, the acid de\elopment, and the other, the firmness of the curd. For the best results, it is better to have the firmness of the curd a trifle ahead of the acid development. When the proper acid development has been reached, the whey must be removed, regardless of the firmness of the curd. If the curd has not become firm enough by natural forces, when the acid development has reached the proper stage to remove the whey, it must be firmed by other means. If it is not firm enough, either by natural or artificial means, when the whey is removed, a sour cheese is the result. The acid development should not be al- CHEDDAR CHEESE-MAKING 201 lowed to go beyond 0.16 to 0.19 of 1 per cent acidity in the whey by the acid test or iV to | of an inch of acid on the hot-iron test, before the whey is removed. 199. Hot-iron test.^ — This test is employed to determine the amount of acid in the curd. A piece of iron, such as an iron pipe two feet long, is heated in the fire to proper temperature. If the iron is too hot it will burn the curd, and if not hot enough the curd will not stick to the iron. When hot, it is taken from the fire and wiped clean with a cloth. A handful of curd is taken from the vat and squeezed dry, either in the hand or in a cloth. This curd is carefully pressed against the hot iron and drawn away. If the iron is at the right temperature and the curd has sufficient acid development, the curd will stick to the iron and when pulled away will form fine threads. The length of these threads determines the amount of acid in the curd. The acid is usually spoken of in terms of the length of threads, as i inch of acid, ^ inch of acid and the like. The curd must have a slight development of acid before it will stick to the iron. This test takes advantage of the peculiar properties ^ of curd which are produced by the action of the acid on the casein. 200. Firmness of the clird. — The cheese-maker must be able to judge the firmness of the curd by physical examination. The particles of curd should have shrunken to about one-half their original size and should be of uniform consistency throughout; they should not have 1 S. M. Babcock, Hot iron test of cheese curd, Wis. Exp. Sta. Kept. 1895, pages 1.33-1.34. 2 Van Slyke, L. L., and E. B. Hart, A study of some of the salts formed by casein and paracasein with acids, their relation to American Cheddar cheese, N. Y. (Geneva) Exp. Sta. Bui. 214, 1902. 202 THE BOOK OF CHEESE any soft centers. The curd should be firm and springy. When a double handful is pressed and suddenly released, the curd particles should spring apart. The curd should have a " shotty " feeling when in the whey. If the curd has attained the proper firmness, and the acid has not reached the correct stage to remove the whey, it may be left in the whey until sufficient acid development has been attained. This is liable to cause the curd to become too firm and to result in a hard dry cheese. If there . is no evidence of the presence of undesir- able organisms, such as bad odors, or gas holes in the curd, it is better to remove the whey and develop the acid when the curd is in the " pack." The pack refers to the first piling of the curd. The whey may be re- moved either by means of a faucet or gate in the vat or by a siphon (Fig. 36). With either form of removal a whey-strainer (Fig. 37) should be used to prevent loss of curd particles. It requires considerable time for the whey to escape from a large vat. After the curd has been heated to the proper temperature, it is well to remove a portion of the whey. In doing this the surface of the w^hey should not be drawn down quite to the top of the curd. When ready, the remaining whey can be quickly removed. If it is decided that the curd is not firm enough, when Fig. 36. -Whey siphon with strainer. CHEDDAR CHEESE-MAKING 203 the whey is drawn down to the surface of the" curd and the acid has developed sufficiently, the curd should be fi.rmed up in the whey by stirring it vigorously by hand before the remainder of the whey is removed. This is commonly called "hand stirring." This difficulty results either from the use of too much starter or from holding the milk until too much acid develop- ment has taken place before adding the rennet. Hand stir- ring accomplishes what natural forces would accomplish if given sufficient time. If the curd does not firm naturally in the whey, there is a large loss of fat and other solids, be- cause the pieces of curd will have to be broken up to allow the water to escape from the soft centers of these masses. This loss can usually be re- duced by firming the curd in the whey or adding water rather than by stirring without either water or whey. If the curd is not properly firmed, it carries extra whey into the cheese. With the increase in whey, the amount of milk- sugar carried into the cheese increases. This extra milk- sugar attacked by bacteria produces an excess of lactic acid, which results in " sour " cheeses. This explains why the curd is placed beyond the danger of over-development of acid by removing so large a portion of the whey. Fig. 37. — Whey strainer with spout to fit into the gate in the vat. 204 THE BOOK OF CHEESE If the curd is properly firmed in the whey and the whey is removed before too much acid has developed, it is im- possible to make a sour cheese. 201. Gathering the curd together. — Before the last of the whey has been remo^'ed, the curd should be pushed back from the faucet into the upper two-thirds of the vat and spread in an even layer. This layer should be six to eight inches thick. The curd can be pushed back with the rake or a board which will fit crosswise in the vat, in which are many holes. As soon as the whey has been removed so that there is not enough to wash the curd into the lower part of the \'at, the vat should be tilted and a ditch eight to ten inches wide cut in the curd through the center. The ciu'd from the ditch should be removed to either side and spread evenly. As soon as all the whey has been removed, the pieces of curd scat- tered about in the vat should be gathered up and placed with the remainder. In some factories, instead of matting the curd in the vat, a curd sink is used. This is a wooden receptacle about the size of the vat but not so deep, with a slatted false bottom. It is fitted with castors so that it can be easily moved about. A cloth is placed in the sink and the curd and whey are dipped upon the cloth. The whey escapes very rapidly through the cloth. The curd sink is an advantage in those cases in which it is de- sirable to remove the whey from the curd quickly, such as high acid curds which have to be hand stirred to firm the curd. The disadvantage lies in the work required to keep the sink and the large cloth clean. 202. Matting or cheddaring is the distinctive feature of the Cheddar process. It is the piling and matting of the curd. Whether the curd is matted in the vat CHEDDAR CHEESE-MAKING 205 or in the curd sink, the process is practically the same. The object of cheddaring is three-fold : (1) to control the incorporation of moisture ; (2) to control undesirable ferments, if present in the curd; (3) to develop the texture desired in the cheeses. After the curd in the vat has become matted so that the particles stick together, the masses on either side of the central channel are cut crosswise into strips with a cheese knife (Fig. 38). The width of the strip depends on the water-content of the curd at this stage. The more water, the smaller should be the pieces of curd. This allows the whey to drain away much more rapidly. As soon as the strips of curd are cut, they should be turned over or stood on edge. A drain should be left along the middle line of the vat and on each side. This permits , , Fid. 3 1 \ pail. settmg (addition oi the rennet) and the pressing of the curd. Less time than this involves loss in yield and quality of the cheese. In other words, the time requirement for these changes cannot be ignored. The object of pressing is not primarily to remove whey but to produce the physical conditions essential to ripen- ing the cheese in a mass and put it in convenient form for handling. The whey should have been removed during the cooking and cheddaring. When ready for the press, the temperature of the curd should be about 80° to 85° F. ; it should be brought down to this point during the milling, salting and hooping processes. If the curd is put to press too warm or too cold, the following results may be expected : Too high temperature during pressing produces several faults, as : 214 TFIE BOOK OF CHEESE (1) Favors the development of undesirable ferments. (2) Causes excessive loss of fat. (3) Gives the curd pieces a greasy surface so that they will not readily pass into a compact cheese. If a cheese is greasy, the bandages will not stick. (4) Favors the formation of mechanical holes in the cheese. (5) Causes " seamy " color in the cheese by the collec- tion of fat between pieces of curd. Too low temperature has its difficulties, such as : (1) The pieces of curd will not fuse together. (2) The rind does not form properly. (3) It appears to cause mottled cheese. The commonly used gang press may or may not have an arrangement to cause continuous pressure to be Fig. 47. — Continuous pressure gang cheese-press. applied to the cheese (Figs. 47, 48). When fresh cheeses are first placed in the press, the pressure should be applied very gradually. The curd, after being cut through CHEDDAR CHEESE-MAKING 215 216 THE BOOK OF CHEESE the mill, will have many exposed fat globules. A heavy pressure at first will force out the whey set free by the extracting power of the salt. The whey will carry away the exposed fat globules, and therefore reduce the yield. As soon as white whey starts from the hoops, the increased application of the pressure should be stopped until the whey regains the appearance of clear brine. More pressure can then be gradually applied until full pressure is reached. The cheeses should remain under heavy pressure for one-half to one hour, when they should be removed from the press and dressed. 207. Dressing the cheese. — When ready to dress the cheese, the press is opened and the hoops turned down. The hoops are opened so that the bandages can be lapped over the top of the cheeses about 1| inches. Before turning a bandage down, it should be carefully pulled up to remove any wrinkles from the sides of the cheese, but not hard enough to pull it free from the bottom. After it is pulled up, the bandage should be lapped over the top about 1 1 inches, and if not even should be trimmed with a sharp knife. It should then be sopped down with warm water. Plenty of warm water to wet the bandage and cloths helps to form a good rind. If starched circles are used, one should be placed on the top of the cheese and sopped down with warm water. If not, the press cloth should be wrung out of warm water and put on smoothly, so there will be no wrinkles. The hoop is then put to- gether and placed back in the press under heavy pressure for twelve to eighteen hours. The pressure should be sufficient to cause the curd particles to unite so that the surface of the cheese will be smooth. The next day the cheeses are taken from the hoops and placed in the curing- room. If they do not come out of the hoop easily, they CHEDDAR CHEESE-MAKING 217 may be loosened by cutting between the sides of the cheese and the hoop with a knife. A special thin-bladed knife for this purpose is called a speed knife (Fig. 49). Care should be taken not to cut the bandage when trying to loosen the cheese. If starched circles are used, the press cloths are removed from the cheese, when they are put in the curing-room. If neither starched circles nor press cloth are left on the cheese in the curing-room, the rind will crack on account of drying out on the exposed surface. This „ ,^ „ , , .. . Fig. 49. — Speed knife. allows mold and m- sects to enter the cheese. The flavor, body and texture and color of the cheese are all dependent on the skill of the cheese-maker and the quality of the milk from which it is made. The finish is dependent entirely on the skill and carefulness of the maker. An operator should see that the cheese press is straight so that there will be no crocked cheese and that the bandage and press cloths are properly put on, because the finish or appearance of the cheese is an index of his ability. 208. Handling over-ripe and gassy milk. — Because it is sometimes necessary to make over-ripe ^ or gassy milk ^ into cheese, special directions or precautions are necessary. The best way is to reject this milk. When it is necessary to make it into cheese, the losses are much 1 Decker, J. W., Cheesemaking from sour milk, Wis. Exp. Sta. Rept. 1898, pages 42-44. 2 Russell, H. L., Cheese as affected by gas producing bacteria, Wis. Exp. Sta. Rept. 1895, pages 139-146. Marshall, C. E., Gassy curd and cheese, Mich. Exp. Sta. Bui. 183, 1900. Moore, V. A., and A. R. Ward, Causes of tainted cheese curds, N. Y. (Cornell) Exp. Sta. Bui. 158, 1899. 218 THE BOOK OF CHEESE more than with normal milk. It is a question of making as good a cheese as possible, and the subject of losses is ignored. (1) Oxer-ripe milk. — The fact that the milk is over- ripe shows that there is already too much acid present. Every effort must be made to get the curd as firm as pos- sible in the whey with the acid development as low as possible or before the acid has had time to develop any more than can be helped. Although the milk is over-ripe, it is a good plan to add about j of 1 per cent of starter just before the rennet. This starter will not begin to work until the curd is being cheddared and it will help the flavor, especially if any bad fermentation should be present. The rennet is added at 80° F., as this lower temperature tends to check the acid development. More rennet is used, commonly from 4 to 4| ounces to 1000 pounds of milk. This gives a quicker coagulation. The curd is cut soft, as this tends to expel the moisture more quickly. The heat is turned on sooner after cutting. The time to turn it on and the length of time to heat are determined by the amount of acid. A curd should not be heated in less than fifteen minutes. If the curd has enough acid and has not begun to firm up much, the whey should be drawn down to the surface of the curd, water the temperature of the whey and curd put into the vat, and the curd firmed up in this water. The water washes the acid out of the curd and because of the lack of milk-sugar checks the acid development. If the milk is not so ripe and the curd nearly firm enough, the whey may be drawn off and the curd firmed up by hard stirring in the vat or sink. The curd should not be pushed back enough to be very deep or thick when ready to cheddar. CHEDDAR CHEESE-MAKING 219 The curd should be cut into very small pieces to cheddar. The smaller the pieces, the faster the whey drains away. Sometimes it is necessary to cut the curd into pieces six inches square. The pieces should not be piled but should be turned often and stood on edge to let the whey drain away and sometimes pressed with the hands to force the whey out. It is often all one man can do to keep the curd turned. The curd is not cheddared very long but is milled early so that the whey can escape. If it is thought that the cheese will be sour, the curd should be washed in cold water to remove the acid and milk-sugar. A little more Fig. 50. — At the left is a regular shaped, close, solid textured cheese; at the right one puffed up with gas. salt is sometimes used. A product made from over-ripe milk, no matter how skillful the cheese-maker, will show traces of a sour cheese. (2) Gassy milk. — If a cheese-maker knows that there is " gassy " fermentation, he should add more starter and develop more acid when ripening the milk to try to overcome this. There are different kinds of gassy fer- mentation. Some produce acid and some do not. Some will not show until the cheeses have been on the curing- room, shelves several days. Others will cause the curd to float in the whey. Usually the gas shows as pin-holes while, the curd is being cheddared. 220 THE BOOK OF CHEESE The gas causes tiny round holes in the cheese, resulting in the cheese swelling or puffing out of shape and some- times breaking open (Figs. 50, 51). The only time to overcome the gas is during the cheddaring process. The curd is piled and repiled until the holes flatten out. This shows that the gas-producing organisms have weakened and will not cause Viwx more holes. Because the curd has Fig. 51. ■ Tliis shows the same cheeses as in Fig. 50, cut open to show the solid and gassy texture. to be piled so many times and so long, the pieces become very thin. The curd is ready to mill when most of the holes have flattened. After milling, the curd should be stirred and aired for some time before salting to allow the bad odor to escape. Because of the high acid development, it often happens that the cheese will not be gassy but will be sour. At best a cheese made from milk having gassy fermentation will have a bad flavor. The quality of the cheese can be CHEDDAR CHEESE-MAKING 221 no better than that of the milk from which it is made, plus the skill of the cheese-maker. 209. Qualities of Cheddar cheese. — The cheese should be neat, clean and attractive. If unclean, and the bandage not put on the cheese properly, it shows that the manu- facturer is not particular to keep the curing-room shelves tidy nor careful and painstaking in dressing. The cheese should not be lopsided or bulged. When cut, it should have a uniformly colored interior. The prin- cipal color defects are too high, or too light color, mottled or seamy. The texture should be solid and close. A common defect is mechanical holes or openings and another is gas pockets. The body can be tested by rub- bing the cheese between the thumb and fingers. It should be smooth and waxy and free from lumps. It should rub down like cold butter. The common defects are graini- ness and lumpiness. Graininess may be caused by too much acid or too much moisture in the cheese. Lumpi- ness is due to uneven curing. If top much moisture is present, the body will be soft and mushy ; if not enough moisture, the body will be hard and dry. The cheese should have a pleasant, clean, mild aroma and the characteristic flavor which is usually somewhat similar to that of nuts and so is spoken of as a nutty flavor. CHAPTER XIII COMPOSITION AND YIELD OF CHEDDAR CHEESE ■ ' So many factors affect the composition and yield of Cheddar cheese that no positive or exact statement can be made unless other facts are definitely known. The following factors affect both the composition and yield : 1. The chemical composition of the milk. 2. Amount of moisture incorporated into the cheese. 3. The amount of solids lost in cheese-making. 4. The skill of the cheese-maker. 5. The bacterial-content of the milk. 210. Composition of milk, whey and cheese. — The following Tables ^ VI, VII, VIII, which are the average of forty-eight factories for the season of 1893, show the minimum, maximum and average composition : TABLE VI Average Composition of the Milk Minimum Maximum Average Water 86.28 88.30 87.28 Total solids 11.70 13.72 12.72 Fat 3.30 4.40 3.77 Casein 2.20 2.85 2.48 Albumin 0.52 0.81 0.69 Sugar and ash, etc. . . 5.63 5.89 5.78 1 Van Slyke, L. L., Investigations relating to the manufac- ture of cheese, N. Y. (Geneva) Exp. Sta. Bui. 68, 1894. 222 COMPOSITION OF CHEDDAR CHEESE 223 TABLE VII Average Composition op the Whey Minimum Maximum Average Water 92.75 93.28 93.00 Total solids 6.72 7.25 7.00 Fat 0.24 0.51 0.38 Casein, albumin . . . 0.66 0.99 0.86 Sugar, ash, etc 5.63 5.86 5.76 TABLE VIII Average Composition of the Green Cheese Water . . . Total solids . Fat . . . . Casein Sugar, ash, etc. Minimum 33.16 66.84 30.00 20.80 4.86 Maximum 43.89 56.11 35.89 25.48 7.02 37.33 62.67 33.41 23.39 5.89 Table VI shows the minimum, maximum and average composition of the milk and Table VIII the composi- tion of the cheese made from that milk. The average composition of the cheese in Table VIII shows that it contains 37.33 per cent of water. The tendency to-day seems to be for a softer cheese so that the average would probably be higher. Table VIII also shows the wide variation in the composition of the cheese. The moisture and total solids both vary about 10 per cent. In order to judge the variation in composition, one must know the 224 THE BOOK OF CHEESE composition of the milk and the moisture-content of the cheese and then only a very inaccurate estimate of the composition of the cheese can be formed. 211. Relation of fat to casein in normal milk. — In order to understand the relation of the composition of the milk to yield of cheese, one must be familiar with the rela- tion of the fat to the casein in normal milk. The follow- ing table ^ shows the relation of fat to casein in normal milk : TABLE IX Summary Showing the Relation of Fat to Casein IN Normal Milk Group Per Cent OF Fat in Milk Number OF Samples Average Per Cent OF Fat in Each Group Average Per Cent OF Casein IN Each Group Average Pounds of Casein for Each Pound of Fat in Milk I . . . 3.0-3.5 22 3.35 2.20 0.66 II . . . 3.5-4.0 112 3.72 2.46 0.66 Ill . . . 4.0-4.5 78 4.15 2.70 0.65 IV . . . 4.5-5.0 16 4.74 3.05 0.64 V . . . 5.0-5.25 7 5.13 3.12 0.61 Table IX shows that the pounds of casein for each pound of fat are not constant but that the casein does not increase in proportion to the fat above 4.0 per cent of fat in the milk. 212. Influence of fat in milk on yield of cheese. — The following table shows the influence which fat in the milk has on the yield of cheese : ^ * Van Slyke, L. L., Investigations relating to the manufac- ture of cheese, N. Y. (Geneva) Exp. Sta. Bui. 62, 1893. COMPOSITION OF CHEDDAR CHEESE 225 TABLE X Summary Showing Relation of Fat in Milk to Yield OF Cheese Group Average Per Cent op Fat in Milk Pounds op Green Cheese Made prom 100 Lb. op Milk Pounds op Green Cheese Made for 1 Lb. OP Fat in Milk I . . . II . . . Ill . . . IV . . . V . . . 3.35 3.72 4.15 4.74 5.13 9.14 10.04 11.34 12.85 13.62 2.73 2.73 2.70 2.71 2.66 Table X shows that as the fat in the milk increases, the pounds of cheese made from 100 pounds of that milk increases ; but the amount of cheese made for each pound of fat in the milk does not increase. This is due to the fact pointed out in Table IX, namely, that as the fat in- creases in the milk the casein does not increase in the rich milk in proportion to the fat. From Tables IX and X this conclusion may be drawn : that as the percentage of fat increases in the milk the more cheese can be made from 100 pounds of that milk, but after the increase in fat gets above 4 per cent the amount of cheese that can be made for each pound of fat in the milk is decreased because the casein does not increase in proportion to the fat. No exact statement of yield can be made without first stating the moisture-content of the cheese. The losses also must be considered. Van Slyke^ in the following Table XI shows the effect of the fat-content of normal milk on the yield of cheese. ^ Van Slyke, L. L., Methods of paying for milk at cheese factories, N. Y. (Geneva) Exp. Sta. Bui. 308, 1908. Q 22Q THE BOOK OF CHEESE The moisture-content of all the cheeses is reduced to a uniform basis of 37 per cent. (See cut showing yield of cheese, Fig. 52.) ' TROM 100 LBS S MILK FROM 100 LBS ■ FROM ~ a'/z MILK 100 LBS 4 MILK Fig. 52. — The figures represent the relative yield of cheese containing different percentages of fat, but all have a uniform content of 37 per cent water. TABLE XI Table Showing the Effect of the Fat-Content of Normal Milk on the Yield of Cheese Per Cent op Fat IN THE Milk Per Cent op Casein in THE Milk Amount op Cheese Made PROM 100 Lb. OP Milk Amount op Cheese Made for Each Pound op Fat IN the Milk 3.00 2.10 8.30 2.77 3.25 2.20 8.88 2.73 3.50 2.30 9.45 2.70 3.75 2.40 10.03 2.67 4.00 2.50 10.60 2.65 4.25 2.60 11.17 2.63 4.50 2.70 11.74 2.61 4.75 2.80 12.31 2.59 5.00 2.90 12.90 2.58 213. Fat loss in cheese-making. — The amount of solids lost in the whey also affects the yield. The follow- COMPOSITION OF CHEDDAR CHEESE 227, ing table gives the amount of fat lost in whey with normal milk containing different percentages of fat : TABLE XII Summary Showing Amount of Fat in Milk Lost in Cheese-making Group Pounds op Fat in 100 Lb. of Milk Pounds or Fat Lost IN Whey fob 100 Lb. op Milk Per Cent op Fat IN Milk Lost IN Whey I . . . II . . . Ill . . . IV . . . V . . . 3 to 3.5 3.5 to 4 4 to 4.5 4.5 to 5 5 to 5.25 0.32 0.33 0.32 0.28 0.31 9.55 8.33 7.70 5.90 6.00 Table XII shows that the percentage of fat in the whey is approximately the same for milk high or low in fat. But the milk low in fat loses a higher percentage of the total milk-fat in each 100 pounds of whey. 214. Effect of bacterial-content of milk on yield of cheese. — The bacterial-content ^ of the milk influences the yield by affecting both the moisture-content and the losses. If the milk is sour or has bad fermentation, the losses will be increased because the curd cannot be care- fully handled, and the moisture cannot be incorporated to the extent that it can in clean milk, without injury to the quality. The proper cooling of the milk in one instance increased the yield 0.3 pound of cheese for each 100 pounds of milk. The more moisture that can be in- corporated into the cheese up to the legal limit, the greater the yield. ^ Farm Bur. Exchange, St. Lawrence Co., N. Y., Vol. 1, no. 9, 1915. Cooling milk before delivery at the cheese factory. 228 THE BOOK OF CHEESE 215. Factors afifecting the moisture-content of Cheddar. — The amount of moisture that can be incorporated in a curd depends on several factors.^ The following in- crease the moisture-content control of the cheese : 1. Cutting the curd coarse. 2. High setting temperature. 3. Low acid in the curd at time of removing whey. 4. Not stirring the curd with the hand as the last of the whey is removed. 5. Slow pressure. 6. High piling of the curd in the cheddaring process. 7. Small amount of salt. 8. Holding the curd at low temperature after the whey is removed. 9. Large amount of rennet. 10. Cutting the curd hard. The following factors decrease the moisture-content of the cheese : 1. Fine cutting. 2. Low setting temperature. 3. High acid in the curd at time of removing the whey. 4. Stirring the curd with the hand as the last of the whey is removed. 5. Fast pressure. 6. Low piling of the curd in the cheddaring process. 1 Sammis, J. L., et al.. Factors controlling the moisture con- tent of cheese curds, Wis. Exp. Sta. Research Bui. 7, 1910. Ont. Agr. College and Exp. Farm Rept. 1909, pages 111- 124, Cheese making experiments. Ont. Agr. College and Exp. Farm Rept. 1910, pages 111-128, Cheese making experiments. Fisk, W. W., A study of some factors influencing the yield and the moisture content of Cheddar cheese, Cornell Exp. Sta. Bui. 334,, pages 515-537, 1913. COMPOSITION OF CHEDDAR CHEESE 229 7. Large amount of salt. 8. Holding the curd at high temperature after the whey is removed. 9. Small amount of rennet. 10. Cutting the curd soft. From this discussion, it is evident that the yield of cheese from 100 pounds of milk increases with higher percentages of fat and casein in the milk, with reduced losses of solids during manufacture, with the absence of undesirable fermentations, and with the incorporation of large amounts of water. 216. Variations of the Cheddar process. — The Cheddar process, as already described, is widely employed in cheese factories. Many varieties are found, however, and varietal names are used for such products. A whole series of these forms are either locally or widely made in England and taught in the English dairy schools. Some of these varieties resemble the factory Cheddar product fairly closely ; others are clearly different products. A typical series of the variations as developed in America will be considered. In the commercial trade Cheddar cheese is usually designated by some name which indicates its size. The size of the cheese is determined by that of the hoops. The hoops vary both in diameter and height. The table on the following page shows the usual sizes of the hoops and the weight and name applied to the cheese. 217. Cheddar-type cheese from pasteurized milk. — Sammis and Bruhn ^ have described a variation of the Cheddar process to overcome the difficulties of making 1 Sammis, J. L., and A. T. Bruhn, The manufacture of cheese of the Cheddar type from pasteurized milk, U. S. Dept. Agr. Bur. An. Ind. Bui. 165, pages 1-95, 1913. 230 THE BOOK OF CHEESE cheese from pasteurized milk. Such milk curdles in very unsatisfactory manner unless some chemical is added to compensate for the salts lost and to offset the other changes resulting from heat. For this purpose, they found the use of hydrochloric acid satisfactory. TABLE XIII Size of Cheese Hoops, Weight, and Term Applied to Diameter of Height op Weight of Cheese Pounds Term Applied to Hoop Cheese Cheese G-7 in. 7-8 in. 9-11 Young America Tapers 5-7 in. 10-14 in. 10-16 Long Horn 12-14 in. 3^-4i in. 18-24 Daisy or Picnic 14-15^ in. 4-6 in. 30-40 Twin (two in same box) 14-16 in. 4-7 in. 35-40 Flat 131-15 in. 10-12 in. 40-50 Cheddar 14-16 in. 12-15 in. 75-90 Export " The acidulation of milk with hydrochloric acid after pasteurization is accomplished without difficulty or danger of curdling by running a small stream of the acid, of normal concentration, into the cooled milk as it flows from the continuous pasteurizer into the cheese vat. One pound of normal-strength acid is sufficient to raise 100 pounds of milk from O.IG per cent to 0.25 per cent acidity (calcu- lated as per cent of lactic acid). The amount of acid needed each day to bring the milk up to 0.25 per cent acidity is read from a table or calculated from the weight of the milk and its acidity, determined by the use of Manns's acid test (titration with tenth-normal sodium hydrate and phenolphthalein) . The preparation of stand- ard-strength acid in carboy lots for this work and the COMPOSITION OF CHEDDAR CHEESE 231 acidulation of milk present no great difficulty to any one who is able to handle Manns's acid test correctly. " After the milk is pasteurized and acidulated three- fourths per cent of first-class starter is added and the vat is heated to 85°. It is set with rennet, using 2 ounces of rennet per thousand pounds of milk, so that the milk begins to curdle in 7 minutes and is cut with three-eighth inch knives in 25 minutes. All portions of the work after adding rennet are carried out in an unvarjdng routine manner, according to a fixed-time schedule every day. As soon as the rennet has been added the cheese maker is able to calculate the exact time of day when each of the succeeding operations should be performed, and the work of making the cheese is thu>s simplified and systematized. It is possible that the routine process here described may be varied somewhat with advantage at different factories." This cheese usually lacks characteristic Cheddar flavor or contains it in very mild form. It therefore satisfies only those who seek very mild flavored products. Efforts are now being made to find a flavor producing substance or organism which will bring the flavor of this product more nearly to that of typical Cheddar. 218. Club cheese is known by a variety of trade names. It is made from Cheddar cheese, so that it is especially liked by persons who care for strong Cheddar flavor. It has a soft texture so that it spreads easily, and is therefore much used for sandwiches. Well-ripened or old Cheddar cheese is ground in a food chopper. The older the Cheddar, the stronger will be the flavor of the club cheese. Cheese of good flavor should be used. In order to do away with all lumps in the texture, it is some- times necessary to run the mixed cheese through the food chopper a second time. While all lumps must be worked 232 THE BOOK OF CHEESE out, care should be taken not to work the cheese so much that it will become salvy and sticky. Usually a little pepper is added, to give the cheese a biting taste. Some manufacturers add a great variety of substances, but these are not necessary and destroy the flavor of the cheese. Club cheese may be wrapped in tin-foil or put up in air-tight glass jars. The latter practice, while more expensive, has the advantage of making the cheese keep longer ; but for local trade tin-foil is just as satisfactory as glass. In filling the glass, care must be taken not to leave any air spaces between the cheese and the glass, as this is likely to permit the cheese to mold. A glass jar can be filled and air spaces prevented by first smearing a very thin layer of cheese over the glass. 219. The stirred-curd or granular process. — The original practice as brought from England and followed in the farm dairies before the de\elopment of the factory system is now known \ariously as the " stirred-curd " or " granular curd " process. With the introduction of the cheese factory, as known to-day, this system was re- placed by the Cheddar cheese. The old farm process is still used on some farms and in a few factories. As the name indicates, the curd for such cheeses is kept stirred so that it remains in granular condition instead of being allowed to mat as in the Cheddar process. The early steps of the two processes are identical. They diverge at the point at which in the factory Cheddar process the whey is drawn and the curd is allowed to mat. In some factories the curd and part of the whey are dipped into a curd sink. This allows the whey to escape more easily and quickly. In the stirred-curd process, the pieces of curd are kept separated by stirring and not COMPOSITION OF CHEDDAR CHEESE 233 allowed to mat. The whey is drawn off and the stirring continued by hand. After stirring fifteen to twenty minutes, the curd becomes so dry as not to mat easily. As soon as the curd has reached this stage, the salt is evenly and thoroughly mixed with it. More salt is added than in the Cheddar process because the curd is more moist than Cheddar curd at the time of salting. The whey freely separating carries away much of the salt. The quantity of salt to use depends on the amount of whey draining from the curd. After salting, the curd is allowed to cool, with occasional stirring to prevent the formation of lumps. The advantage of the stirred-curd practice lies in the shorter time required for making cheese and in the greater yield due to increased water-con- tent. It has several disadvantages, among them being : (1) lack of control of undesirable fermentation; if gas organisms are present, the cheeses more frequently huff than with the Cheddar system ; (2) there is more fat lost while stirring the curd, hence quality and yield suffer; (3) the water is not so thoroughly incorporated, which more frequently results in mottled cheeses; (4) the body is commonly soft and " weak," shows mechanical holes, and cures too rapidly. These faults are closely correlated with the presence of higher percentages of water than in cheeses made by the Cheddar process. In other words, the stirred-curd process usually produces a cheese with higher water-content, hence more subject to the development of unfavorable fermentation than the Cheddar cheeses. 220. California Jack cheese ^ is very similar to the stirred-curd or granular j)rocess. This cheese was orig- inally made in Monterey County on the coast of Cali- ^ New York Prod. Review, Vol. 34, no. 2, page 66. 234 THE BOOK OF CHEESE fornia, about twenty-five years ago, in small quantities, but after it was found to sell well other counties started to manufacture it. As Monterey was the first county to make this product, it was named " Monterey " cheese. In order to distinguish the cheese made in other counties from this, it was suggested that it be given a name and, consequently, it was called " Jack " cheese. This has been accepted as its true name. The cheese is made mostly by Portuguese and Italian-Swiss, although some of the best of the variety is now manufactured near Modesto, California. This cheese is adapted for manufacture on small dairy farms, where there is inexpensive and scanty equip- ment. The smaller sizes of cheese are made and ripened quickly. It has become widely used in California. The cheese is made every morning, from evening's and morning's milk. The former is put into the cheese vat at night, and morning's milk is added as milking is going on. When the milk is all in the vat, it is immedi- ately warmed to 86° to 88° F. and rennet extract is added (when milk has 0.2 to 0.21 of 1 per cent acidity) at the rate of 6 to 8 ounces to 1000 pounds of milk. No coloring matter is used. It is ready for the curd-knife in thirty to thirty-five minutes, its readiness being determined the same as in making Cheddar cheese. The curd is first cut lengthwise of the vat with the horizontal curd-knife and allowed to stand until the whey rises over and partly covers the curd, when it is cut again with the vertical curd-knife crosswise of the vat. It is then hand-stirred, gently at first, and the stifring is finished with the rake. Either a steam-heating or self-heating vat is used (the steam-heating vat is preferred) and temperature increased about one degree in five minutes. The curd is heated to COMPOSITION OF CHEDDAR CHEESE 235 98°F. in winter, and to 105° F. to 1 10° F. in summer. After temperature is up, it is stirred occasionally with a rake until the whey is drawn at 0.14 to 0.15 of 1 per cent acidity. The curd is hand-stirred as soon as the whey is nearly drained off, and raked to each side of the vat to drain more thoroughly, when it is quickly stirred again to keep it from lumping or matting. Salt is now added at the rate of l| pounds to 100 pounds of curd, and stirred in thor- oughly several times. During the salting process, cold water is allowed to run under the vat, the hot water hav- ing been run off previously. Curd is put into cloths at a temperature of 80° to 85° F. No cheese hoops are used. Two sets of press cloths are necessary ; one set is ready to use while the other is still on the cheese in the press. These press cloths are about one yard square. The press cloths are all laid out evenly one on top of the other, as many as there are cheeses. They are then taken together and spread out over the top of a large, open tin milk-pail, and pushed down in the center to the bottom of the pail, with the edges hang- ing over the top. A common one-gallon lard pail is used to measure the curd into the press cloths. A lard pail full will make a cheese weighing six and one-half pounds, which is the popular size. After a pailful has been put into the press cloth, the four corners are caught up with the left hand, while with the right hand the curd is formed round and the press cloth straightened and the other corners in turn taken up. The press cloth is now taken up tight over the curd with the left hand, while the cheese is given a rolling motion on the table with the right hand, pressing at the same time to expel some of the whey. This twists the press cloth tight over the curd, 236 THE BOOK OF CHEESE ^vhere it is tied with a stout string. After fixing them all (as many as there are cheeses) in this way, they are ready for the press. The cheeses are pressed between two wooden planks, 12 inches wide, 1§ inches thick, by whatever length is reqiiireii for the nmnber of cheeses to be pressed. One plank is nailed on supports at a convenient height from the floor on a little slant for the whey to drain off better. The cheeses in the press cloths are placed at the proper distance apart so they do not touch. Then the other plank is put squarely over the top of the cheese and levers about four feet long at an interval of five feet are placed over this plank, from a cleat in the wall, on the other end of which is placed a hea\y weight of about 100 pounds, which acts as an automatic pressure. The cheeses are left in the press until the next morning, when they are taken out and put on the shelves in the curing-room. The cheeses have no bandage or covering, and do not seem to crock, and they form a very good rind. The cheese is a sweet \'ariety, weighs six and one-half pounds cured and cures in about three weeks ready to ship, and sells at 10 to 25 cents a pound wholesale. Most of the work seems to lie in forming and rolling the curd in press cloths before pressing. Trouble is experienced by the makers, especially in warm climates in summer, in not having the milk at a uniform acidity when rennet is added. Great improvements could be made in this cheese by using an acidimeter, paraffining and curing the cheese in an even temperature, not much over 60° F. Old and hard Jack cheese is also employed for grat- ing and cooking, while the fresh is used for the table. 221. The washed-curd process has been developed in recent years largely in the state of New York. In COMPOSITION OF CHEDDAR CHEESE 237 this mctliofl, a rcj:jular Cheddar curd is made up to the time of mi^iIlf,^ This curd is washed or soaked in cold water during or directly after millinj^. The theoreti- cal object of this washing is to carry away bad flavors and to reduce over-development of acidity by washing away all traces of whey. However, cheese-makers soon found that it increased the yield and this led some to carry it to extremes. After the curd has been milled, it is covered with cold water. The temperature of this water ranges from 50° F. to 70° F. The curd is stirred in this water for various lengths of time according to the judgment of the cheese-maker. This time varies from five miimtes to one hour. Some- times the vat is partly filled with water and the curd milled directly into the water. This process has certain advantages and disadvantages. The advantages are : if too much acid has developed in the curd, this washing will reduce it so that the cheese will not l)e sour. Sometimes when bad flavors are present in the curd, washing will tend to overcome or remove them. Its disadvantages are : the larger yield due to excessive soaking tempts the makers to soak curd beyond the time needed to relieve the initially sour condition. Curd soaked in this way produces cheeses containing percentages of water so high as to lower their quality. This increases the yield sometimes as much as 3 to 5 per cent. Such a cheese is very soft in texture and does not cure like a Cheddar cheese which has not been washed. Part of the lactic acid, milk-sugar ^ and the ^ Babeoek, S. M., e^ al., Cheese ripening as influenced by sugar, Wis. Exp. Sta. Rept. 1901, pages 162-167. E. G. Hastings, et al., Studies on the factors concerned in the ripening of Cheddar cheese, Wis. Exp. Sta. Research Bui. 25. 238 THE BOOK OF CHEESE inorganic salts are removed by this washing. A \\ ashed- curd cheese will sometimes rot, due to the activity of the putrefactive bacteria, and to the lack of the restraining effect of the lactic acid-forming bacteria. Some washed- curd cheeses are so soft that they will not retain their normal shape. A washed-curd cheese is never sour because the milk- sugar and lactic acid have been removed by washing. 222. English dairy cheese. — In some localities cheeses* are still made on the farms. These are mostly produced* after the stirred-curd process, hence are soft-bodied and. open-textured. They usually weigh ten to twelve pounds* and are three to four inches thick and twelve inches in. diameter. 223. Pineapple cheese. — This variety derives its name from the fact that the cheeses are made in about the size and shape of a pineapple. The curd is made after the Cheddar process from either whole milk or partly skimmed milk. It is pressed in molds shaped like a pineapple. The cheeses are then hung in nets to give the checked appearance on the surface. They are rubbed with linseed oil to prevent the surface cracking, and finally are shellacked. 224. Leyden. — Among specialties, a cheese called Ley- den originating in Holland is made in Michigan and New York. This is a part skim cheese heavily spiced with caraway seed. The ripe cheese is colored red as it goes to market. 225. Cheddar cheese with pimientos. — Recently some Cheddar cheeses have been made with pimientos added. This gives a mixture of characteristic Cheddar and pimiento flavors, which seems to be desired by some persons. An ordinary Cheddar curd is made and the COMPOSITION OF CHEDDAR CHEESE 239 pimientos added just before salting. The pimientos are ground rather coarsely and then added to the curd to- gether with the liquid which was with the pimientos in the can. The pimiento should be thoroughly and evenly mixed with the curd to insure a uniform distribution and mottled color in the cheese. The salt is then applied. The remainder of the process is the same as for ordinary Cheddar cheese. 226. Sage cheese is a product flavored from the leaves of the ordinary garden sage. It is made by two methods : one, in which the sage leaves are used, and the other, in which a part of the curd is colored to imitate that given by the sage leaves, and sage oil or tea is used to give the flavor. In the leaf method, a regular Cheddar cheese curd is made up to the time of salting. Just before the salt is added, sage leaves are mixed with the curd. The leaves should be dried and freed from stems and other coarse particles and the leaves themselves broken up rather finely. The leaves are then added at the rate of 3 ounces for every 1000 pounds of milk. Care must be exercised to see that the leaves are evenly mixed through the curd or an evenly mottled cheese will not result. The salt is then added. This sequence seems to increase the absorption of the flavor by the curd. If these cheeses are consumed as soon as well cured, no fault can be found. On the other hand, if they are held for any length of time, yellow areas form about each piece of sage leaf ; the leaves decay rapidly and spoil the cheese. This method gives a very true flavored sage cheese, the only objection being that it cannot be held in storage for any length of time without a marked deterioration. 240 THE BOOK OF CHEESE In the otlier method of making; sage cheese, either a vat with a movable partition or a hirge and a small vat must be used. In many cases the receiving can is used as the small vat. After the milk is properly ripened and ready to set, one-sixth to one-seventh of the milk is put into the small vat. To this small vat, green coloring mat- ter is added. Juice from the leaves of corn, clover, or spinach was formerly used as coloring. Consequently the manufactiu-e of sage cheese by this method was limited to the seasons of the year when these leaves could be obtained. Now, however, the dairy supply houses have a harmless green color paste which is much cheaper and can be secured at any season of the year. The amount of color paste to use will vary from 30 to 35 c.c. for every 1000 pounds of total milk. This should be added to the small vat of milk. It gives a green milk and later a green curd. Both vats are worked along together, until the time for remo\ing the whey. Then the partition in the vat is removed or the small vat is mixed with the large one. The green curd should then be e^■enly mixeening, considered from a chemical standpoint. 237. Action of the rennet extract. — Some authorities hold that rennet extract contains two enzymes, rennin and pepsin, while others thmk it is a single peptic fer- CHEDDAR CHEESE RIPENING 251 ment. These enzymes produce effects ^ closely related to, if not identical with, those of pepsin in the following par- ticulars : neither the rennet enzyme nor pepsin causes much, if any, proteolytic change except in the presence of acid ; the quantitative results of proteolysis furnished by the rennet enzyme and pepsin agree closely, when working on the same material under comparable condi- tions ; the classes of soluble nitrogen compounds formed by the two enzymes are the same, both quantitatively and qualitatively ; neither enzyme forms any considerable amount of amido compounds and neither produces any ammonia ; the soluble nitrogen compounds formed by both enzymes are confined to the group of compounds known as paranuclein, caseoses and peptones. Rennet exerts a digestive effect on the casein ^ which is intensified by the development of acid in the curd. The soluble nitrogenous products formed in Cheddar cheese by the rennet enzymes are the albumoses and the higher peptones. Experiments show that no flavor develops until the amido acids and ammonia are formed. When the rennet enzymes were the only digesting ferments in the cheese, there was no trace of cheese flavor. This is probably due to the fact that the rennet enzyme changed the casein into caseoses and peptones but did not form amido acids and ammonia. Some authorities ^ think 1 Van Slyke, L. L., et al., Action of rennin or casein, N. Y. (Geneva) Exp. Sta. Tech. Bui. 31, 1913. Van Slyke, L. L., et al., Cheese ripening investigations ; rennet enzyme as a factor in cheese ripening, N. Y. (Geneva) Exp. Sta. Bui. 233, 1903. 2 Bosworth, A. W., Studies relating to the chemistry of milk and casein, N. Y. (Geneva) Exp. Sta. Tech. Bui. 37, 1914. 2 Wis. Exp. Sta. Rept. 1898, Distribution of galactase in milk from different sources, pages 87-97. Wis. Exp. Sta. Rept. 1903, pages 195-197, 201-205, 222-223, Action of proteolytic ferments on milk. 252 THE BOOK OF CHEESE that the enzyme galactase carries the ripening of the protein from this stage. The question arises whether these intermediate compounds must be found before other agents can form the amido acids and ammonia. TABLE XVI Showing the Effect of Different Amounts of Rennet Extracts on the Rate of Formation of Soluble Nitrogen Compounds in Cheese Ripening quantitt op Rennet Added per 1000 Lb. of Milk Per Cent op Water Soluble Nitrogen Compounds in THE Cheese Initifil 32 days 80 days 270 days 2oz. 4 oz. 8 oz. IG oz. 0.14 0.16 O.K) 0.14 0.47 0.75 0.90 1.26 0.68 1.13 1.50 1.70 1.30 1.74 1.97 2.04 The above table shows that the more rennet extract used the faster the cheese cures, measured by the amount of water-sohible nitrogen compounds formed in the cheese. 238. The action of the bacteria. — Authorities ^ dis- agree as to the groups of bacteria found in Cheddar cheese. This may be due to lack of proper classification. Some of the groups are : Bacterium lactis acidi, B. coll communis, B. lactis aerogenes, B. casci, Streptococci, B.^ Bulgaricum and IVIicrococci. Authorities agree that the B. lactis acidi group is the most prominent. This group makes up 90 per cent or more of the total bacteria 1 Wis. Exp. Sta. Rept. 1900, pages 102-122. 2 Harding, H. A., and M. .J. Prueha, The bacterial flora of Cheddar cheese, N. Y. (Geneva) Exp. Sta. Tech. Bui. 8. 3 Bacterium, Bacillus and Lactobacillus are preferred by dif- ferent authors as generic placing of the Bulgarian sour milk species. CHEDDAR CHEESE RIPENING 253 flora of the cheese in the early stages of ripening. In the course of a few weeks, however, this group is largely replaced by the B. casei group.^ TABLE XVI Showing the Number of Bacteria to a Gram in Cheddar Cheese as Determined by Lactose-Agar Plate Cul- tures Time of Plating Cheese Number 680 581 682 683 Milk . . 8,000,000 500,000 700,000 500,000 Curd at salting time . 160,000,000 326,000,000 912,000,000 839,000,000 12 hours 332,000,000 1,048,000,000 623,000,000 965,000,000 1 day 586,000,000 736,000,000 709,000,000 569,000,000 2 days . 235,000,000 405,000,000 848,000,000 580,000,000 4 days 145,000,000 684,000,000 522,000,000 1,025,000,000 6 days . 165,000,000 184,000,000 853,000,000 184,000,000 14 days . 51,000,000 211,000,000 369,000,000 401,000,000 21 days . 284,000,000 290,000,000 348,000,000 319,000,000 28 days . 285,000,000 453,000,000 314,000,000 144,000,000 35 days . 104,000,000 261,000,000 326,000,000 504,000,000 49 days . 132,000,000 228,000,000 436,000,000 661,000,000 70 days . 128,000,000 291,000,000 193,000,000 168,000,000 98 days . 114,000,000 212,000,000 45,000,000 55,000,000 From Wis. Bui. 150. 1 Hastings, E. G., Alice C. Evans and E. B. Hart, The bac- teriology of Cheddar cheese. Wis. Exp. Sta. Bui. 150, pages 1-52, 1912. 254 THE BOOK OF CHEESE The large number of bacteria in the cheese is very striking. The number as given in the accompanying table is not that actually in the cheese, as it is very difficult to obtain the sample in suitable condition for plating.^ The principal action of the lactic acid-forming bacteria in the cheese ripening is the changing of the milk-sugar or lactose into lactic acid and the formation of small amounts of other substances, such as acetic, succinic and formic acids, alcohol, aldehydes and esters and some gases, carbon dioxide and hydrogen. While the amount of these substances other than lactic acid is small, it is thought that the effect of these on the cheese may be im- portant. Heinemann shows - that lactic acid exists in two optical modifications, the levorotatory and dextroro- tary acids. In cheese they are usually found in the inac- tive or racemic form, the levorotatory and dextrorotary acids being present in equal amounts. What impor- tance the question of optical activity of the lactic acid may assume is not definitely known. Just as some groups of bacteria have a specific effect on the lactose, producing only one modification of lactic acid, so bacteria attacking lactic acid may exercise a selective action and use only one or the other optically active modification. In other words, the early fiora of cheese-ripening bacteria may determine the later flora by the production of a form of lactic acid attacked by one group of bacteria and not by another, and the effect on the flavor will differ accordingly. The amount of lactic acid in the cheese increases for a time, then decreases. ' Harding, H. A., The role of the lactic acid bacteria in the manufacture and in the early stages of ripening of Cheddar cheese, N. Y. (Geneva) Exp. Sta. Bui. 237, 1903. 2 Heinemann, P. G., The kinds of lactic acid produced by lactic acid bacteria, Jour. Biol. Chem., Vol. 2, pages 603-608. CHEDDAR CHEESE RIPENING 255 The errors in determining lactic acid are considerable. It seems that the tendency is toward an increase of lactic acid in the cheese long after the lactose has disappeared. Two explanations are offered : one, that in the lactic acid fermentation an intermediate compound or compounds are formed which exist for some time, the conversion into lactic acid being complete at about three months; the other is that lactic acid is formed as a product of para- casein proteolysis. The lactic acid formed in cheese ripening does not exist in a free state but reacts with the calcium salts in the cheese and forms calcium lactates. It is thought that there is sufficient of these salts to neutralize all the acid formed, and therefore the acid does not enter into combination with the paracasein salts. It has been found that lactates are the principal source of acetic and propionic acids. These are supposed to have some effect on the flavor of the cheese. The effect of lactic acid as a determinant of bacterial and enzymic changes is very important. Early in the ripening process, lactic acid suppresses the growth of un- desirable micro-organisms. It also furnishes the acid medium necessary for the best action of both the coagulat- ing and peptic enzymes. The importance of the lactic acid bacteria in cheese ripening has been summed up by Hastings ^ as follows : " The functions of this group of bacteria in Cheddar cheese are through their by-product lactic acid as follows : (a) To favor the curdling of milk by rennet, (h) The bacteria of the milk are held in great part in the curd. Through the acid they influence the shrinkage of the curd and 1 Hastings, E. G., et al., The bacteriology of Cheddar cheese, U. S. Dept. Agr. Bur. An. Ind. Bui. 150, 1912. 256 THE BOOK OF CHEESE expulsion of the whey, (c) The acid so changes the nature of the curd as to cause ' matting,' or ' cheddaring ' of the curd, (d) The acid activates the pepsin of the rennet extract, (e) The acid prevents the growth of putrefactive bacteria in the cheese. (/) It has been shown that Bacterium lactis acidi is able to form acid in the ab- sence of the living cell, (g) The development of Bacterium lactis acidi is followed by the growth of another group of acid-forming bacteria, the Bacillus Bulgaricus group. They reach numbers comparable with those of the first group, reaching their maximum number within the first month of ripening. Since they develop after the fermenta- tion of the milk-sugar, they must have some other source of carbon and of energy than milk-sugar." It is also prob- able that other groups constantly present contribute to the changes. From the preceding discussion it is evident that each of the ripening agents has its important part to play in the ripening process and a normal ripening of the cheese is a composite result of these various agencies. 239. Conditions affecting the rate of cheese ripening. — The rate at which these agents cause ripening of the cheese depends on several factors.^ Most of these factors are within the control of man. They are as follows : the length of time ; temperature of the curing-room ; moisture- content of the cheese ; size of the cheese ; the quantity of salt used ; the amount of rennet ; the influence of acid. 240. The length of time. —The water-soluble nitro- gen compounds increase as the cheese ages, other conditions being uniform. The rate of increase is not 1 Van Slyke, L. L., and E. B. Hart, Conditions affecting chemical changes in cheese ripening, N. Y, (Geneva) Exp. Sta. Bui. 236, 1903. CHEDDAR CHEESE RIPENING 257 uniform; it is much more rapid in the early than in the succeeding stages of ripening. 241. The temperature of the curing-room. — Very few cheese factories have made any provision for regulat- ing the temperature of the curing-room. Without such provision the temperature follows closely that of the out- side air. In some cases the curing-room is located over the boiler-room and hence becomes very hot. In the cheese warehouses, provision has been made to control the temperature very closely. Experiments show that the soluble nitrogen compounds increase, on the average, closely in proportion to an increase of temperature, when the other conditions are uniform. The temperature of the curing-room has a material effect on the quality of the cheese. Cheese made from the same day's milk, and part cured at 40° F., part at 50° F., part at 60° F. show considerable differences, the great- est seeming to be in the flavor and texture. Those kept at the low temperature cure more slowly and develop a mflder flavor, those at the higher temperature cure faster and develop undesirable flavors. At the higher tempera- ture the undesirable organisms seem to be more active. Some very skillful makers and judges of cheese have always contended that if Cheddar is properly made, firmed to the body and texture of a high-class cheese, ripen- ing at 55 to 60° F. gives a higher quality. Such a cheese must be low in moisture, perhaps 3 to 5 per cent lower than one cured successfully by the cold process. The following tables ^ XVII, XVIII show the effect of different temperatures of curing cheese on the total score and on the points of the flavor, body and texture : ^ Van Slyke, L. L., et al.. Cheese ripening at low tempera- tures, N. Y. (Geneva) Exp. Sta. Bui. 234, 1903. 258 THE BOOK OF CHEESE TABLE XVII Table Showing the Relation of Temperature of Curing TO Total Score Temperature of Curing 40° 50° 60° Total Score 95.7 94.2 91.7 TABLE XVIII Table Showing the Relation of Temperature of Curing to Score of Body and Texture, and Flavor Temperature op Curing 40° F. 50° F. 60° F. Body and texture . Flavor 23.4 47.4 32.0 46.4 22.2 44.8 Of the three temperatures of curing, the lowest gave a higher total score and a higher score for flavor, body and texture. The curing temperature should not go low enough to freeze the cheese, as this lowers the quality. The cheese will cure very slowly and have a mealy texture. 242. Moisture-content of the cheese. — Other condi- tions being equal, there is a larger amount of water- soluble nitrogen compounds in cheese containing more moisture than in that containing less moisture. There- fore, a high moisture-content of the cheese causes it to cure faster. The presence of moisture also serves to dilute the fermentation products which otherwise would accumulate and thus check the action of the ripening agents. CHEDDAR CHEESE RIPENING 259 243. The size of the cheese. — Cheeses of large size usually cure faster than smaller ones, under the same conditions. This is due to the fact that the large cheeses lose their moisture less rapidly by evaporation and there- fore after the early period of ripening have a higher water- content. 244. The amount of salt. — The relation of salt to the rate of ripening is more or less directly associated with the moisture-content of the cheese, since an in- crease in the amount of salt decreases the moisture. Thus, cheese containing more salt forms water-soluble nitrogen compounds more slowly than that containing less salt. The salt also has a direct effect in retarding one or more of the ripening agents. 245. The amount of rennet extract. — The use of in- creased amounts of rennet extract in cheese-making, other conditions being uniform, results in the production of increased quantities of soluble nitrogen compounds in a given period of time, especially such compounds as paranuclein, caseoses and peptones. 246. The influence of acid. — It is necessary that acid be present but the exact relation of varying quanti- ties of acid to the chemical changes of the ripening pro- cess is not fully known. If too much acid is present, it imparts a sour taste to the cheese. It also causes the texture of the cheese to be mealy or sandy instead of smooth and waxy. Conditions that may increase the rate of ripening : 1. Increase of temperature. 2. Larger amounts of rennet. 3. More moisture in the cheese. 4. Less salt. 260 THE BOOK OF CHEESE 5. Large size of the cheese. 6. Moderate amount of acid. Conditions that may retard ripening ; 1. Decrease of temperature. 2. Smaller amounts of rennet. 3. Less moisture in the cheese. 4. More salt. 5. Small size of the cheese. 6. No acid or an excess of acid. 247. Care of the cheese in the curing-room. — The cheeses need daily attention while in the curing-room (Fig. 53). They should be turned e^'ery day to prevent sticking and molding to the shelf and to secure an even evaporation of moisture. If not turned, the moisture will not evaporate evenly from all surfaces and will result in an uneven distribution in the cheese, which causes uneven curing, and usually gives the product an uneven color. The surface of the cheese should be watched to see that the cloths stick. If they do not, the surface will crack, due to the exaporation of the moisture. If the cloths are loosened, they should be removed and the surface of the cheese greased with butter. The grease will tend to prevent the rind from cracking. If the surface of the cheese is not smooth, due to wrinkles in the bandage, or if it cracks, due to the lack of cloths, it furnishes the opportunity for insects to lay their eggs and the larvae to develop within the cheese. Molds also lodge and grow in such cracks. The cheese should be kept clean while in the curing- room. This means that the hands of the person handling the cheese must be clean. The shelves should be washed CHEDDAR CHEESE RIPENING 261 262 THE BOOK OF CHEESE with good cleaning solution and scalded with hot water whenever they become greasy or moldy. Some means should be provided for regulating the temperature and humidity of the curing-room. In most factories this is accomplished by opening the doors and windows at night to admit the cool air and closing them in the morning to keep out the hot air. Care should be taken to keep the doors and windows closely secured. The windows should have shades to keep out the sun. If the room becomes too dry, the floor may be dampened with cold water. The length of time in the curing-room depends on how often shipment is made to some central warehouse or to the market. This usually \aries from two to six weeks. When the surface of the cheese becomes dry and the rind is well formed, the cheese may be paraffined. It usually requires four to six days after cheeses are taken from the hoop before they are ready for this process. The object of paraffining is to prevent the escape of mois- ture and to keep the cheese from molding. 248. Evaporation of moisture from the cheese during ripening. — The losses due to evaporation while the cheeses are curing are a considerable item. The rate of evaporation depends on the temperature and humidity of the curing-room, the size of the cheese, the moisture- content and protection to the surface. Table XIX ^ shows the effect of size of cheese and temperature of the curing-room, on losses while curing. This table shows that the evaporation of moisture is more as the size of the cheese decreases and the tempera- ture is increased. This is probably due to the fact that ^ Van Slyke, L. L., et a!., Cheese ripening at low temperatures, N. Y. (Geneva) Exp. Sta. Bui. 234, 1903. CHEDDAR CHEESE RIPENING 263 the smaller cheese has more surface to a pound than a large cheese. The evaporation increases with tempera- ture, probably because of lowered relative humidity. The humidity can be tested with an hygrometer. TABLE XIX Showing the Variation of Losses in Weight of Cheddar Cheese while Curing, Due to Size of Cheese and Tem- perature OP Curing-Room Weight op Cheese IN Pounds Weight Lost per 100 Pounds of Cheese in 20 Weeks at 40° F. 50° F. 60° F. 70 45 35 2.5 2.7 3.9 4.6 2.4 3.7 5.9 8.1 4.2 5.1 8.5 12.0 The higher the moisture-content of the cheese, usually the more rapid is the evaporation. This is due to several causes : there is more moisture to evaporate ; the mois- ture is not so well incorporated ; a moist cheese does not form so good a rind. 249. Paraffining ^ consists of dipping the cheese in melted paraffin at a temperature of about 220° F. for six seconds. Fig. 54 shows an apparatus for paraffining. This leaves a very thin coat of paraffin on the cheese ; at a lower temperature, a thicker coat would be left. The thicker coating is more liable to crack and peel off. If the cheese is not perfectly dry before it is treated, the paraffin will blister and crack off. ^ Doane, C. F., Methods and results of paraffining cheese, U. S. Dept. Agr. Bur. An. Ind. Circ. 181, pages 1-16, 1911. 264 THE BOOK OF CHEESE Before a cheese is paraffined, the press cloth is removed and also the starched circles, if loose. After a cheese has been paraffined, if the coating is not broken, the loss due to evaporation is greatly reduced. The amount of paraffin to coat a 35-pound cheese will depend on the temperature of the paraffin and the length of time the cheese is immersed. Usually at 220° F. it requires about 0.15 of a pound for each 35-pound cheese. After the cheeses have been paraffined, they may be left on the curing-room shelves I — g or boxed ready to ship. Ij^^^BiB^^BH 250. Shipping. — When ready to ship, each cheese should be carefully and accurately weighed and boxed. Usually these cheeses are boxed after being paraffined. If press cloths are left on the cheese in the curing-room, they should be removed just before weigh- ing. These cloths should not be left in a pile in the factory after being removed as they have been known to heat and sometimes cause fires. They should be washed clean and dried ready for use again. If starched circles are used, they should be left on the cheese. A scale board should be placed on each end of the cheese to prevent its sticking to the box and also to keep the box from wearing the surface of the cheese. The box should be a trifle larger in diameter than the cheese so that the latter can be easily placed in it. The sides of the box should be the same height as the cheese. Fig. 54. — A parafSner for cheese. CHEDDAR CHEESE RIPENING 265 The weight of each cheese should be neatly and accu- rately marked on each box. Care should be exercised to keep the boxes clean. DEFECTS IN CHEDDAR CHEESE A great number of defects may occur in Cheddar cheese. Certain of these are due to known causes and proper remedies are definable, while neither cause nor remedy has been found for other defects. Some of the common defects and their causes and remedies are discussed under different headings of the score-card as : defects in flavor, their causes and remedies; defects in body and texture, their causes and remedies; defects in color, their causes and remedies ; defects in finish and their causes and remedies. 251. Defects in flavor. — Any flavor differing from the characteristic Cheddar cheese is a defect. Certain of these defective flavors can be recognized and causes and remedies given for them, while others may be distin- guished as such but no cause or remedy can be given. 252. Feedy flavors. — Flavors may be characteristic of certain feeding stuffs. Feeding strong-flavored foods, such as turnips, cabbage, decayed silage, certain weeds and sometimes rank green feed, give their peculiar flavors to both milk and cheese. Freshly drawn milk usually absorbs these odors from the air in barns filled with such foods. Certain of these materials may be fed just after milking in moderate amounts without affecting the milk drawn at the next milking. Others should not be used. Milk should not be exposed to strong volatile odors. Some of the objectionable odors may be removed by airing the curd for a longer time after milling before the salt is applied. 266 THE BOOK OF CHEESE 253. Acid flavors. — A cheese with an acid flavor has a pronounced sour smell and taste. This is caused by the over-development of acid which may be due to any of the following causes : (a) receiving milk at the factory which is sour or has too high development of acid ; (b) using too much starter; (c) ripening the milk too much before adding rennet ; (d) not firming the curd sufficiently in the whey before removing the latter ; (e) developing too much acid in the whey before it is removed ; (/) re- taining too much moisture in the curd. The trouble can be reduced or eliminated by one or more of the following precautions : (a) receiving only clean, sweet milk at the cheese factory; (b) main- taining the proper relation between the moisture and acidity ; (c) adding the rennet at the proper acidity ; (d) using less starter ; (e) adding the rennet extract so that there will be sufficient time to firm the curd before the acid has developed to such a stage that it will be necessary to draw the whey ; (/) producing the proper final water-content in the newly made cheese. 254. Sweet or fruity flavors. — These are the sweet flavors characteristic of strawberry, raspberry and the like. Such flavors are very objectionable and usually increase with the age of the cheese. The\- appear to be caused by : (a) carrying both milk and whey in the same cans without properly cleaning them ; (6) expos- ing milk near hog-pens where whey is fed ; (c) dirty whey tanks at the cheese factory; (d) micro-organisms which get into the milk through any unclean conditions. These troubles can be controlled : (a) if milk and whey must be carried in the same cans, the cans should be emptied immediately on arrival at the farm and thor- oughly washed and scalded; (6) the whey vat at the CHEDDAR CHEESE RIPENING 267 factory should be kept clean and sweet ; (c) the starter must have the proper clean flavor. Other defects may be classed as " ofl^ flavors," " dirty flavors," " bitter flavors " and the like. These are un- doubtedly due to unsanitary conditions whereby undesir- able organisms get into the milk, even though the particular organism is often not determined. The flavors may be improved by the use of a clean-flavored commercial starter and by airing the curd after milling before salting. The best remedy is to remove the source of the difficulty. 255. Defects in body and texture. — The body and texture should be close. A sample rubbed between the thumb and fingers should be smooth and waxy. Any condition which causes a body and texture other than this is to be avoided. 256. Loose or open texture. — A cheese with this defect is full of irregularly shaped holes and usually soft or weak-bodied. This is serious if the cheese is to be held for some time. Moisture and fat are likely to collect in these holes and cause the cheese to deteriorate, thereby shortening its commercial life. Several causes may bring about this condition : (a) insufficient cheddaring ; (b) pressing at too high a temper- ature ; (c) inadequate pressing ; (d) development of too little acid. The corresponding remedies are : (a) cheddar the curd until the holes are closed and the curd is solid ; (b) cool the curd to 80° F. before putting to press ; (c) press the curd longer, possibly twenty-four to twenty-six hours ; (d) develop a little higher acid in the whey before re- moving the curd. 257. Dry body. — A cheese with this defect is usually firm, hard and dry, sometimes rubbery or corky. This 268 THE BOOK OF CHEESE may result from lack of moisture, fat or both, and may be due to the following causes : (a) making the cheese from partly skimmed-milk ; (b) heating the curd in the whey for too long a time ; (c) heating the curd too high ; (d) stirring the curd too much in the whey or as the last of the whey is removed ; (e) using too much salt ; (J) develop- ing of too much acid in the whey ; (g) curing the cheese in too hot or too dry a curing-room ; (h) not piling the curd high or fast enough in the cheddaring process. The cause should be located and the corresponding remedy found, as follows : (a) make cheese only from whole milk ; (h) draw the whey sooner ; (c) firm the curd at as low temperature as possible in the whey ; (d) stir the curd in the whey only enough to keep the curd par- ticles separated but do not hand-stir it ; (e) use less salt ; (/) develop less acid in the whey ; (g) cure the cheese in a cool moist ctiring-room ; (h) pile the curd sooner and higher during the cheddaring process. The number of cj^uses which may singly or in combina- tion produce dry cheese demands experience and technical skill that calls for the development of a high degree of judgment. 258. Gassy textured cheese. — Gassy cheese has large numbers of very small round or slightly flattened holes. When round these are called " pin-holes," and when slightly flattened " fish eye " openings. These are due to the formation of gas by the micro-organisms in the cheese. When a cheese is gassy, it usually puffs up from gas pressure as in the rising of bread. If enough gas is formed, it will cause the cheese to break or crack open. Instead of being flat on the ends, such a cheese becomes so nearly spherical as to roll from the shelf at times. CHEDDAR CHEESE RIPENING 26.9 The gas-producing organisms enter because of unclean conditions somewhere in the handhng of the milk and the making of the cheese. Some of the common sources of gas organisms are: (a) unclean milkers; (6) dirty cows ; (c) aerating the milk in impure air, especially air from hog-pens where the whey is fed ; (d) allowing the cows to wade in stagnant water or in mud or in filthy barnyards and then not thoroughly cleaning the cows before milking; (e) exposing the milk to the dust from hay and feed ; (/) dirty whey tanks ; (g) drawing milk and whey in the same cans without afterward thoroughly washing them ; (h) unclean utensils in the factory ; (i) using gassy starter; (j) ripening cheese at high temperatures. Some of these causes are within the control of the cheese-maker after the making process is begun. Many of them are avoided only by eternal vigilance. Among the recommendations for meeting gassy curd are the following: use only milk produced under clean sanitary conditions ; use a clean commercial starter. If gas is suspected in the milk, a larger percentage of commercial starter should be used. More acid must be developed before the whey is removed. If the gas shows while cheddaring, the curd should be piled and replied until the holes -flatten out before milling. The curd should be kept warm during the piling or cheddaring process. This may be accomplished by cover- ing the vat and setting a pail or two of hot water in it. After milling, the curd should be stirred and aired for a considerable length of time before salting. This will aerate the curd and allow it to cool. The cheese should then be placed in a cool curing-room. (See handling of gassy milk.) 270 THE BOOK OF CHEESE 259. Acidy, pasty or soft body and texture. — A cheese with acidy body may be either hard and dry or soft and moist. It has a mealy or sandy feeHng when rubbed between the fingers. The causes and remedies are the same as for cheeses with acid flavors. When rubbed between the fingers, it is pasty and sticks to the fingers. It is caused by the cheese containing too much water. (See control of moisture.) 260. Defects in color. — Any color which is not uni- form is a defect. The proper color depends on the market requirement. Some markets prefer a white and others a yellow cheese ; however, if the color is uniform, it is not defective. Mottled color is a spotted or variegated marking of the cheese. Several causes may give the same general effect : (a) uneven distribution of moisture, the curd having extra moisture being lighter in color ; (6) neglecting to strain the starter ; (c) adding the starter after the cheese color has been added ; (d) mixing the curd from different vats. Remedies for this mottled color are : (a) to maintain a uniform assimilation of moisture (see discussion of mois- ture) ; (b) to strain the starter to break up the lumps be- fore adding to the milk ; (c) to add all of the starter be- fore adding the cheese color ; (d) not to mix curds from different vats. Seamy color. — In " seamy " colored cheese, the out- line of each piece of curd may be seen. There is usually a line where the surfaces of the curd come together. It may be caused by the pieces of curd becoming greasy or so cold that they will not cement. This may be remedied by having the curd at a temperature of 80° to 85° F. when put to press. If it is greasy, this may be removed by washing the curd in cold water. CHEDDAR CHEESE RIPENING 271 Acid color. — This is a bleached or faded color and is caused by the development of too much acid. (See acid flavor for causes and remedies, page 266.) 261. Defects in finish. — Defects of this class differ from those previously mentioned in being entirely within the control of the cheese-maker. All are due to carelessness or lack of skill in manipulation. Anything which detracts from the neat, clean, workmanlike appear- ance of the cheese is a defect that may interfere with the sale of an article intrinsically good. Some of the common defects are : (a) unclean surfaces or dirty cheese ; (6) cracked rinds ; (c) moldy surfaces ; (d) uneven sizes ; (e) cracked cheese ; (/) wrinkled bandages ; (g) uneven edges. CHEDDAR CHEESE JUDGING Judging of cheese is the comparison of the qualities of one product with those of another. To make this easier it is customary to reduce the qualities of the cheese to a numerical basis. This is accomplished by the use of a score-card, which recognizes certain qualities and gives to each a numerical value. Each of these score-cards gives a perfect cheese a numerical score of 100. Two score-cards are used to judge cheese, one for export and the other for home-trade product. The latter is more commonly used. Export Scobe-card Home-trade Score-card Flavor 45 Body and texture . . 30 Color 15 Finish 10 Flavor 50 Body and texture ... 25 Color 15 Finish 10 Total 100 Total 100 The same qualities are recognized in each score-card, but different numerical values are given them. 272 THE BOOK OF CHEESE 262. Securing the sample. — The sample of cheese to be examined is best obtained by means of a cheese-trier (Fig. 55). This is a piece of steel about five or six inches long fitted with a suitable handle. It is semicircular in shape, about | to f of an inch in diameter. The edges and end __=,__.__ ^^^ sharpened ^^^ ^7*"" ^^**" 7 to aid in cut- ting. This is Fig. 55. - A cheosc-trier. inserted into the cheese and turned around and then drawn out. It removes a long cylinder of cheese, commonly called a " phig." This plug should be draw^n from the top rather than from the side of the cheese, because when the bandage is cut it often splits, due to the pressure against it and so exposes the cheese. 263. How to determine quality. — As soon as the plug has been removed, it should be passed quickly under the nose to detect any volatile odors which are liable to leave the cheese quickly. Next, the compactness of the plug should be noticed and the color carefully ex- amined. Then the outer end of the plug should be broken off and placed back in the cheese in the hole made by the trier. It should be about an inch long and pushed in so that the surface of the cheese is smooth. This prevents mold and insects entering the cheese. Usually the cheese will mold after a short time where the plug has been removed. The remainiler of the plug should be saved for determining the flavor and the body and texture. The flavor can be determined by the first odor obtained from the cheese on the trier and by mixing or crushing a piece of the plug between the thumb and fore-finger and CHEDDAR CHEESE RIPENING 273 then noting the odor. Mixing and thoroughly warming causes the odor to be much more pronounced. The cheese should seldom be tasted to determine the flavor, for when many are to be judged, they all taste alike after the first five or six. This is probably due to the cheese adhering to the teeth, tongue and other parts of the mouth, making it difficult to cleanse the mouth sufficiently. The body and texture can be determined by the appearance and the feeling of the cheese when rubbed between the thumb and fingers. The body and texture are distinct, yet they are more or less inter- changed. The body refers to the cheese as a whole and the texture to the arrangement of the parts of the whole. The openness of texture or the holes can be noted when the plug is first removed. The firmness of body and smoothness of texture can be determined when the cheese is rubbed between the thumb and fingers. The color can be judged when the plug is first removed. The finish or appearance may be noted either before or after the other qualities by carefully examining the cheese. Cheddar cheese should have a neat, clean, attractive appearance; when cut it should show a close, solid, uni- formly colored interior. It should have a clear, pleasant, mild aroma and a nutty flavor. It should possess a mellow, silky, meaty texture and when rubbed between the thumb and fore-finger should be smooth and free from hard particles. 264. Causes of variations in score. — It is very seldom, if ever, that a cheese is given a perfect score, for it usually has one or more defects which may be hardly noticeable or very pronounced. The seriousness of the defect is de- termined by the individual tastes of the judges and the 274 THE BOOK OF CHEESE Sample.. CHEESE SCORE-CARD Date.... SCORE REMARKS 50 25 15 10 Body and Color Total 100 Recommendations., Name of Judge.. SUGGESTIVE TERMS Clean FLAVOR Desirable Pleasant Aroma Nutty Flavor l/ndesirable Due to Farm Conditions Weedy Feedy Cowy Old Milk Bitter Due to Factory Conditions Too much acid Too little acid Due to either Farm or Factory Conditions Yeasty Fruity Fishy Rancid Sour Bitter Sweet Tainted BODY AND TEXTURE Desirable Smooth Waxy Silky Close Undesirable Pasty Greasy Curdy Mealy Lumpy Corky Loose Gassy Yeasty Acidy Sweet Watery Too dry COLOR Desirable Uniform Undesirable Streaked Mottled Acid cut White specks Wavy Too high Seamy Rust spots Too light FINISH Desirable Clean surfaces Neat bandage Attractive Undesirable Wrinkled bandage Greasy Unclean surfaces No end caps Cracked rinds Uneven edges Undesirable size CHEDDAR CHEESE RIPENING 275 market requirements. It is customary for the judge to pick out several samples and score them in order to fix the standard and if there are several judges this serves to unify their standard. Ordinarily judges will vary because of their individual tastes, unless they begin with a uniform standard. Certain markets require cheese with given qualities which on other markets would be considered defects. For example, the Boston market requires a very soft, pasty cheese which other markets would consider un- desirable. The cheese is constantly undergoing changes due to the ripening agents so that it may not always be scored the same. For example, a cheese may have little or no flavor and after several weeks a very considerable flavor may have developed. This is probably due to the action of the ripening agents, and therefore the second time it would be scored differently. 265. The score-card. — ■ When judging several samples of cheese, the type of score-card on the opposite page is used for each one. This gives the date of judging and the sample number, the judge's name and reasons for cutting the score and recommendations to avoid these troubles. CHAPTER XV THE SWISS AND ITALIAN GROUPS Certain varieties of hard cheese of foreign origin are now made to some extent in this country. If not manufactured in sufficient quantities to supply the demand, the remainder is imported. These hard cheeses are now considered. SWISS CHEESE Swiss cheese, variously known as Gruyere, Emmenthal, Schweitzer and Swiss, had its origin in the Alpine cantons of Switzerland. From this region its manufacture has been carried by Swiss dairy-men and emigrant farmers into widely separate lands. The Swiss colonies settled in the United States in the Mohawk Valley and in Catta- raugus County, New York; in Wayne, Stark, Summit, Columbiana and Tuscarawas counties of Ohio, and in Green and Dodge counties in Wisconsin. Of all these, the Wisconsin colonies have become the most extensive. Similar colonies have developed the making of this type of cheese in Sweden and Finland. 266. The Swiss factory. — Swiss cheese cannot be made in a vat like other t^'pes for reasons that will be explained later. In place of the vat is used a kettle, generally of copper, and it may or may not be jacketed for steam or for hot water (Fig. 50). These kettles vary in capacity from GOO to 3000 pounds of milk. The cheese- 276 THE SWISS AND ITALIAN GROUPS 277 Fig. 56. — Swiss-cheese kettle. maker takes the best care possible of his kettle, for an unclean utensil is one of the easiest sources of contamina- tion of the milk. When the kettle is not jacketed, and it is only in recent years that this has been done, it is suspended in a fireplace by means of a crane arrange- ment. This fireplace uses wood, and is built of brick or stone, so that the kettle rests on the edge and is provided with a door which swings upon another crane, and can be closed while the fire is going. When the kettle is swung on a crane, it is possible to swing it under the weigh-stand for filling. This requires a lid to swing down over the fire, and keep the room free from smoke. The chimney generally has a rather high stack to secure a good draft. This kettle is fastened to the crane by a large iron band passing around the neck, to which a bail or handle is attached. The kettle may be raised or lowered by means of a simple screw on this beam. The crane consists of a heavy beam working in sockets in the floor and a beam or cross brace, which has another and shorter beam braced to it, to take the weight of the kettle. The weigh-stand, and its efficient location, is a matter of extreme importance. It is elevated a little above the remainder of the floor to allow gravity to do the work. The next most important equipment is the press and draining table. The table is made of wood or stone, and has a slight slope to allow the whey to drain 278 THE BOOK OF CHEESE off. The press is generally a jack screw which, braced against a beam, will exert an enormous pressure on the table below. Swiss cheeses are made in two styles, the " round " or drum and the " block " or rectangular forms, each of which has its advantages. For the round style, which is most commonly made, the forms for hooping are of metal or of elm wood, and consist of strips of a given width, generally six inches, but of an undetermined length. These strips are then made into a circle and held by a cord, which is easily lengthened or shortened, thus vary- ing the diameter of the hoop. Besides these hoops, cheese boards or followers are needed. These are hea^'y circular boards, of a size to fit that of the cheese generally made, and are banded with iron around the edge and cross-braced on the bottom for rigidity. The small tools of the factory consist of knives to cut the curd, and of a " Swiss harp " or other similar tool to stir the curd. JNIany clean bandages are also needed, and a kettle brake. 267. The milk. — Swiss cheese requires clean sweet milk. Dirt, high acid and infections with undesirable bacteria involve difficulties of manufacture and frequent losses of cheese. One common practice rejects milk if it shows acidity above 0.15 per cent. To secure milk in this condition, factories are small and located so close to the producing farms as to secure 1000 to 3000 pounds of milk delivered warm from the cow twuce a day. The cheese is made twice daily from this fresh milk. If, however, milk is properly cared for, it is possible to mix night's and morning's milk without bad results. In fact, in working experimentally with high grade milk and taking precautions against loss of fat, it has been THE SWISS AND ITALIAN GROUPS 279 necessary to skim (separate) part of the milk, thus re- ducing the ratio of fat to casein. Analysis of good Swiss cheeses shows that the desired texture is more uniformly obtained with milk in which the fat is less than the normal ratio. This assumes that the manufacturing loss is kept down so that the fat removed offsets the extra loss from curd-breaking. 268. Rennet extract. — Most Swiss cheese-makers pre- fer to make their own rennet extract from the stomach. This results in a product which is not uniform in strength and so requires good judgment to secure the desired coagu- lation in the allotted time. Some cheese-makers roll fifteen to twenty well salted calves' stomachs together and dry them. From this they cut off a definite amount each day to be soaked for twenty-four hours in two to five quarts of whey at 86° F. Four quarts of this solution added to 2000 pounds of milk at 90° F. should produce a curd ready for cutting in twenty to thirty minutes. 269. Starter. — Makers do not agree as to the use of " starters " for Swiss cheese. Those opposed to such use say that a starter will give the cheese a decided Cheddar flavor, while those in favor of it state that it will control undesirable fermentations, and that, with the use of a starter, it is possible to make Swiss cheese throughout the year, and have uniform success. Doane,^ working with Bacillus Bulgaricus as a starter, found that these starters did not always overcome the undesirable fermentations. If a cheese-maker is having difficulty to develop the holes or " eyes," this may be 1 Doane, C. F., and E. E. Eldredge, The use of Bacillus Bul- garicus in starters for making Swiss or Emmenthal cheese, Dept of Agr. Bur. An. Ind. Bui. 148, 1915. 280 THE BOOK OF CHEESE overcome by making a starter ^ as follows from good cheese and whey or milk : Select a cheese which has the desirable " eyes " or holes and a good flavor. Grind up some of this and add about ^ of a pound to one gallon of milk or whey. Hold this for twenty-four hours at a warm temperature (85° to 90° F.). Strain it into the vat of milk just before the rennet is added. 270. The making process. — The milk is delivered twice a day without cooling. It usually reaches the factory at a temperature of 92° to 96° F. It is strained into the kettle, and starter and rennet added at the same temperature as received. (For method of adding rennet, see Chapter V.) Enough rennet should be used to give a coagulation ready for cutting in twenty to thirty minutes. The firmness of the curd is tested by inserting the index finger in an oblique position, then raising it slightly and with the thumb of the same hand starting the curd to break or crack. When the curd is coagulated ready for cutting, it will give a clear break over the finger. It is important to keep the temperature uniform while coagulation is in process, and this is best accomplished by the use of a little pan arrangement which fits into the top of the kettle. When this is full of water at 100° F., the temperature of the air above the milk will be about 90° F. When the curd is ready for cutting, a scoop may be used and the top layer carefully turned under to equalize the temperature more closely. Cutting the curd. — In some cheese factories, knives resembling Cheddar cheese knives are employed to cut the curd. In other factories, a " Swiss harp " is used to break the curd. The curd is usually cut or broken 1 N. Y. Produce Rev. and Am. Creamery, Vol. 37, no. 25, page 1112, Starter for Swiss cheese. THE SWISS AND ITALIAN GROUPS 281 into pieces about the size of kernels of corn. The practice of " breaking " curd instead of cutting it with sharp curd-knives produces excessive loss at times. Experimental study has shown that the loss of fat may be kept as low as 0.3 per cent if modern curd- knives are substituted for the breaking tool formerly used. Study of Swiss cheeses of all grades supports the opinion that the removal of a small part of fat from usual grades of factory milk produces a better quality of product than the use of rich whole milk. This may be accomplished through the escape of fat in the whey on account of breaking the curd and stirring it vigorously, or by skimming a part of the milk which is then curdled, cut and stirred under such conditions as to minimize the loss of fat. Cooking the curd. — After cutting, the curd is stirred in the whey for about twenty minutes before the steam is turned on and is then heated to 128° to 135° F. While this heating is in progress, constant stirring must be given to avoid matting. This excessive stirring breaks the curd up into pieces about the size of wheat kernels, and accounts for the large fat loss, which is one of the main sources of loss in making Swiss cheese. This stir- ring is accomplished by a rotary motion, and the use of a brake, which is a piece of wood closely fitting the side of the kettle. This creates an eddy in the current at that point and gives a more uniform distribution of tempera- ture. The process of cooking takes from thirty to forty minutes, and at the end of that time the degree of tough- ness may be determined by making a roll of curd in the hand, and noticing the break when it is given a quick flip. A short sharp break indicates the desired toughness. 282 THE BOOK OF CHEESE Draimng and hooping. — In this process, the cheese- makers' skill is displayed. With the hoop prepared, and the curd at the correct stage of toughness, the operator takes a press cloth, wets it in whey, slips it over a flexible iron ring which can be made to fit the shape of the kettle, gives the contents of the kettle a few swift revolutions, then suddenly reverses the motion, with the result that the contents form into a cone, and the ring and bandage are dexterously slipped under this cone, and drawn up to the surface of the whey with a rope or chain and pulley. This part of the process is the most important, as a cheese must have a smooth firm rind, else it will quickly crack. With too large a batch of milk, the curd can be cut into two pieces and hooped separately. With the mass of curd at the to]) of the whey, the i)ie('e of perforated iron plate just the size of the hoop is slipped under the mass, and attached to the pulley by four chains. Then the top of the mass is carefully leveled oft", because while still in the whey, it cannot mat badly and so tend to develop a rind crack. Now the mass is raised clear of the whey, and run along a short track to the drain table, where it is put in the press. Pressing. — The mass of curd is dropped into the hoop, the edges of the cloth carefully folded under, and the cloth laid on toj), then the pressure is ap- plied, gradually at first, but increasing until the final pressure is about fifteen to twenty pounds to a pound of cheese. During the first few hours the cloths must be changed frequently, and the cheese carefully turned over each time, to secure a more uniform rind. After a time the changes are less frequent, and at the end of twenty-four hours the cheese is taken to the salting-room. THE SWISS AND ITALIAN GROUPS 283 Salting may be done by either the brine or dry method. To prepare a brine bath, add salt to a tank of water until it will float an egg, and add a pailful or more of salt every few days thereafter to keep up the strength. The cheese is then placed in this bath and left for three to five days, depending on the saltiness desired. As the cheese floats with a little of the rind above the surface, it should be turned a few times to insure uniformity of salting. With dry salting, the salt is rubbed on the cheese by hand or with a stiff brush, and any excess carefully wiped off, leaving only a slight sprinkle on the surface to work into the cheese. 271. Curing Swiss. — From the salting-room, the cheese goes to the first one of two curing-rooms, where the unique process of the development of the characteristic eyes takes place. During the curing period of either round or block Swiss, constant attention must be paid to the cheese. They must be turned every day at first, and then every second or third day toward the end of the curing period. Also, great care must be taken that no mold starts growing, as it will soon work into the cheese, and spoil its flavor. The best way of preventing mold is by washing the cheese, in either clean or slightly salted water, as often as possible. A stiff brush is mostly used for this. The development of the " eyes " or holes is the diffi- cult part of the whole process. It is not known exactly what , causes the development, but it is attributed to micro-organisms or enzymes. The gas in these eyes has been examined and found to be carbon dioxide and free nitrogen. Sometimes hydrogen is found. This comes from the original fermentation of the milk-sugar and 284 THE BOOK OF CHEESE remains to contaminate the normal eye. The nitrogen ^ is inckided from the original air. Propionic acid is formed at the same time as the eyes, and they are said to be the result of a propionic ferment of lactic acid. The interior of the cheese is anaerobic, due to low permeability and high oxygen-absorbing quality. This propionic bacterium cannot, however, account for all the carbon dioxide produced. After the eyes have started, their further development depends on temperature and humidity of the air, and on the moisture of the cheese, as regulated by the amount of salt used. The first room has a temperature of 70° F. to start the eyes, which is later lowered in the second curing-room to about 60° to check the development. When any local fermentive action starts, it may be checked by rubbing salt on the affected part. The humidity of the room is very important, because a cheese will quickly dry out in a dry room, due to evap- oration from the surface. To prevent this, it is well to spray the floor with water, or to have a steam jet in the room. If the curd has been cooked too long the cheese may be too dry. Such cheeses may be piled two or more deep 1 Clark, W. M., On the formation of "ej'es" in Emmenthal cheese, Jour. Dairy Sci. 1 (1917), no. 2, pages 91-113. Among important studies of Swiss cheese ripening are the foUowng : Freudenreieh, E. v., and Orla Jensen, Ueber die in Emmentalerkiise stattfindende Proprionsauregarung, Centralb. f . Bakt. etc. 2 Abt. 17. page 529. Jensen, Orla, Biologische Studien iiber den Kiisereifungs- prozess unter spezieller Berucksiehtigung der tliichtigen Fett- sauren, Centralb. f. Bakt. etc. 2 Abt. 13 (1904). page 161. Eldredge, E. E., and L. A. Rogers, The bacteriology of cheese of the Emmenthal type, Centralb. f. Bakt. 2 Abt. 40 (1914), no. 1/8, pages 5-21. THE SWISS AND ITALIAN GROUPS 285 in the ciiring-room. It is held by some cheese-makers that this process causes them to absorb more moisture. Probably this is due to the checking of evaporation. The development of the " eyes " may be watched by trying the following test : Place the middle finger on the cheese and let the first finger slip from it, striking the cheese smartly ; a dull sound indicates solidity, while a ring indicates a hole, and an expert maker can tell the size of the holes by the sound. This requires long practice for the operator to become proficient. After a cheese has remained in the first room for about two weeks and the holes are well started, it is removed to the second curing-room, which is held at a cooler temperature and slightly drier atmosphere. The cheeses are held in this room from three to ten months, depend- ing on market conditions, and capacity of the curing- rooms. In Switzerland, it is customary to hold cheese to secure a well ripened product, while in America most of the cheeses are shipped comparatively green, hence do not bring so high a price. 272. Block Swiss. — In making block Swiss, the same procedure is followed through the cooking stage. Then the curd is pressed in a square form or in one large piece, each form six inches square on the ends and twenty inches long, and later cut into sections. These are then pressed, salted and cured in the same way as round forms. In this type of cheese there is a much smaller cross-section ; therefore the development of holes is much more easily controlled on account of the ease with which the salt can work into the cheese and control undesirable fer- ments. As it is easy to control, this variety is made in the fall and winter when the ferments are especially hard to keep in check. However, this cheese has the 286 THE BOOK OF CHEESE disadvantage of cutting eye-development short by the rapid entrance of salt. The curing consists of the developing of the flavor and eyes and the changing in body and texture. Just what causes these changes is not known. 273. Shipment. — When ready for shipment, the drum cheeses of the same general diameter are sorted out and packed four to six in a cask. Care must be taken to put boards between them to prevent sticking. These are called scale-boards, and are made of thin sections of wood fiber. The cheeses are crowded into the cask to miake a snug fit, and the head carefully fastened. 274. Qualities of Swiss cheese. — The peculiar Swiss cheese flavor may be characterized as a hazel-nut taste. It is a trifle sweet and very tempting. The " eyes " or holes should be about the size of a cherry with a dull shine to the inner lining. The " eyes " usually contain a small amount of a briny tasting liquid. These eyes should be unifornjy distril)uted. The color should be uniform. The cheese should have a neat, clean, attractive appearance, and the rind should not be cracked or broken. There are several common defects in Swiss cheese. If the milk is not clean-flavored, the cheese will have the same flavor as the milk. The greatest difficulty is to produce the eyes or holes. A cheese which does not have these is called " blind." A product which has many small pin-holes due to gassy fermentations is called a " niszler " ; this means a cheese with a thousand eyes. If gas forms in the cheese and causes cracks, it is called " glaesler." If the cheese contains too much moisture, it will be soft and pasty. Such a cheese does not readil;^' form eyes. THE SWISS AND ITALIAN GROUPS 287 275. Composition and yield. — A large number of analy- ses of Swiss cheese have been made but there is wide variation. This is due to the fact that the composition and yield are both dependent on the following factors : composition of the milk, losses during manufacture, amount of moisture in the cheese. The losses in Swiss cheese are much larger than with some of the other hard cheeses, such as Cheddar. This is because more fat is lost in the whey, due to breaking instead of cutting the curd and the subsequent hard stirring. The pos- sibility of reducing these excessive losses has already been indicated. Swiss cheeses of high grade show about the following range of composition: Water 30-34 per cent Fat . . . . ' . . 30-34 per cent Protein 26-30 per cent Ash 3-5 per cent Salt (NaCl) . . . . 1-1.4 per cent The water-content of this t^pe of cheese is low and the protein-content is proportionately high. Both condi- tions lead to firm textures, long ripening and long keeping periods. The following score-card is used to judge both block and drum Swiss cheese : Flavor 35 Appearance on trier holes ... 30 Texture 20 Salt 10 Style . _5 100 288 THE BOOK OF CHEESE The yield of Swiss cheese varies from S to 11 pounds to 100 pounds of milk. The more solids in the milk, the more moisture incorporated in the cheese ; the smaller the loss of solids in the manufacturing process, the larger will be the^ yield from a given amount of milk. THE ITALIAN GROUP ^ A group of varieties, best known in America by Parme- san, are made in Italy with related forms in Greece and European Turkey. These forms are very hard, usually uncolored, with small eyes or holes. They are made in large cheeses which ripen very slowly. Cow's milk is regularly used for Parmesan and Grana in northern Italy ; other varieties contain goat or sheep milk or vari- ous mixtures. Aside from Parmesan, few of the other forms are known outside the place of origin except as they are exported in a small way to satisfy the demand of emigrants from these regions. 276. Parmesan. — One type of Italian cheese, how- ever, the Parmesan, has become very widely known. In general the consuming trade does not discriminate be- tween Parmesan, Grana and closely related forms. Par- mesan is made in large cheeses which require one to three years for proper ripening ; in texture it is very hard with small eyes or holes formed by \Try slow fermentation. Such cheeses are ripened in large storehouses in which 1 Gorini, C, Studi sulla fabricatione razionale del fromaggi Grana, Boll, iiflf. del JSliiiistero Agi*. Tnd. e Comm. Anno X, serie C, Fasc. 10, pages 1-7, Roma, 1911. Gorini, C, On the distribution of bacteria in Grana cheese, Centralb. f. Bakt. etc. 2 Abt. 12 (19(14). pages 78-81. Fascetti, G., The technological chemistry of the manufacture of Grana cheese in Reggio, Staz. Sper. Agr. Ital. 47 (1914), no. 8, pages 541-568. THE SWISS AND ITALIAN GROUPS 289 hundreds and even thousands are brought together and cared for by experts. The surfaces of these cheeses are kept clean and free from insects by rubbing with linseed oil. So hard are these forms that the cheese- trier is not used in testing, but the texture of the surface is tested by pricking with an awl-like tool and the stage of eye-formation and associated ripening is determined by the soiuid given out when the cheeses are tapped with a hammer. When ripe, the cheeses of this group are used in cooking princiijally. The broken cheese is grated and added to macaroni, spaghetti and other cooked cheese dishes. Parmesan is usually made from partly skimmed-milk ; the ratio of fat to protein in analysis runs from 1 : 2 to 3 : 4 in contrast to the normal relation of about 4:3 in whole- milk cheese. In water-content much variation is found, but ripe Parmesan is usuially about 30 per cent water. Other members of the group are made with difi'erent amounts of skimming, some of them from whole milk. The group in general represents the requirements of cheese for the trade of warmer regions (see Mayo and Elling) : (1) a low fat-content so incorporated that the cheese does not become greasy or oily in hot weather ; (2) a water- content low enough to prevent rapid spoilage during the necessary exposure of handling under warm conditions. The equipment for Parmesan manufacture has more resemblance to that of the Swiss factory than the English and American cheeses. The milk is curdled in deep copper kettles (Fig. 57), below which there is com- monly a provision for direct heating by fire which is sometimes carried on a truck, and therefore can be with- drawn when heating is sufficient. The steam-jacketed kettle has replaced this earlier form to a large measure. 290 THE BOOK OF CHEESE The general character of the manufacturing process is indicated in the following abstract of one of the methods. Many variations are to be found. The milk for Parmesan is allowed to stand overnight. Some acidity is, therefore, developed in contrast to the absolutely fresh condition of the milk used in Swiss and the acidification developed during the making of Cheddar (Fascetti). It is then skimmed, heated to 72° to 75° F. Rennet is added in amount sufficient to produce firm ciu'd in one hour or slightly less. When the curd is firm, Fig. 57. — Parmesan cheese kettles. a wood fire is made under the kettle and the curd is broken with a special implement into small particles. After breaking, four grains of powdered sulfur to twenty- two gallons of milk are added. The curd is stirred with a rake. By the time the temperature rises to 77° F., the curd should be in very small pieces. Stirring and heating continue until the temperature reaches 131° F. At this temperature, it stands fifteen minutes, after which it is removed from the fire (or the fij*e is drawn). Nine- tenths of the whey is then drawn. The cheese-maker then collects the curd into a compact lump under which THE SWISS AND ITALIAN GROUPS 291 he slips a cheese cloth. With the aid of an assistant he removes the mass to a perforated vessel for draining. After this the curd goes into large wooden hoops, lined with cloth, which stand upon a slanting draining table until evening. No pressure is used. Before night they are taken to the cellar. The cloths are removed next day. After standing four days, they are salted by cover- ing the upper surface with coarse salt. This is repeated with daily turning for twenty days, then salted on alter- nate days for another period of twenty days. At the end of the forty days' salting, the cheese is removed from the hoop, scraped, sprinkled with whey and the rind rubbed smooth. A dressing of linseed oil either with or without bone black is applied. The cheeses are kept in special ripening rooms. 292 THE BOOK OF CHEESE and rubbed frequently with linseed oil to keep the surfaces free from molds and vermin. Careful grading as to qual- ity of product and consequent response to ripening con- ditions produce cheeses of many degrees of excellence. Those in which a ripening of three to four years is possible arc most highly esteemed. 277. Regianito. — A cheese of the Italian group is now made in Argentina and imported to the United States under the name Regianito. CHAPTER XVI MISCELLANEOUS VARIETIES AND BY- PRODUCTS As already discussed in Chapter VI, there are a large number of varieties of cheese. Very many are entirely unknown in America, A considerable number of forms are occasionally imported and may be found by visiting the markets and delicatessen stores in the foreign dis- tricts of our large cities. Certain forms not widely known are made in America in a few factories or are imported in sufficient (juantity to call for brief discussion. Some of these are brought together here. The importance of the by-products of cheese-making has not been sufficiently recognized, for manufacture on a large scale is only beginning to be appreciated in America. Certain cheese names, such as Mysost, are applied to whey products. In addition, milk-sugar is extensively made and whey-butter has been carefully studied and found to be practicable under some conditions. 278. Caciocavallo originated in Italy, but is now made in certain factories of New York and Ohio. Some factories in Lombardy^ use whole milk, others use half-skimmed milk. The latter practice is probably the more common. In making this cheese, the milk is coagulated with rennet, cut and firmed in the whey, allowed to settle and the whey 1 Cornalba, G., Caciocavallo in Lombardy, L'Industria del Latte 3, page 105, Abs. in Jahresb. f. Tierchemie 36 (1906), page 250. 293 294 THE BOOK OF CHEESE drawn. The curd is then piled on the draining table and allowed to mat or fuse into fairly solid masses. After several hours of draining and matting, the curd is cut into strips and placed in a vat of hot water. In the hot water, the blocks of solid curd melt into taffy-like masses which are worked and molded by hand into more or less standard shapes. Indian club or ten-pin forms are most commonly produced. When the proper shape has been gained, each mass is thrown into cold water which solidifies it in that form. Cheese masses heat and cool slowly ; several hours of cooling are required to insure a firm cheese. The newly made cheeses are salted in a brine bath, then hung by a string to ripen. KSometimes these cheeses are eaten fresh, again they are ripened several months. They vary in size from one to six ])()unds. Cornalba gives the composition of Italian caci()('a^■allo made from whole milk as water 32 to 34 per cent, fat 34 to 36 per cent, protein 2S.5 to 29.5 per cent, salt 1.7 to 1.8 per cent; when made from half skimmed-milk, water 28 per cent, fat 27 to 28 per cent, protein 35 to 40 per cent, salt 2.2 per cent. Other analyses vary widely from these figures on account of the diti'ering fat-content of the milk. No standardized practice ha-s been established in America. Promlono resembles Caciocavallo in method of manu- facture and composition, the main difference being in the shape of the cheese. It is more or less round and is held by a coarse net made of small rope. The cheeses are treated while curing the same as Caciocavallo. 279. Sap sago. — This hard green cheese imported from Switzerland is made in cakes, tapering from perhaps two inches in diameter to a rounded top with a height of about two inches. These are made from skimmed-milk curd, partially ripened then mixed with powdered leaves MISCELLANEOUS VARIETIES, BY-PRODUCTS 295 of Melilotus cceruleus, a clover-like plant. The mixture is then pressed into the market form and dried until very hard. It is handled without special care since the water- content is so low that fermentations are exceedingly slow. This low-priced cheese may be used in cooking. 280. Albumin cheese.^ — In the rennet cheeses, the albumin, which constitutes about 0.7 per cent of the milk, passes off in the whey. This albumin is not curdled by rennet. It is, however, coagulated by heating. The presence of acid hastens such coagulation but does not cause it when used alone. When the whey is heated to about 200° F., the albumin rises and may be skimmed off. In this form it is recovered and used. It may be shaped is hoops under pressure, as Ricotte, an Italian form. This cheese is pressed firmly and dried. Such albumin is frequently prepared as a poultry feed. 281. Mysost, Norwegian whey cheese. — The whey contains nearly 5 per cent of milk-sugar which can be recovered by boiling. The Norwegian process which produces Mysost consists in raising the whey to the boil- ing point, skimming off the albumin as it rises, then con- centrating the remainder of the whey. As it reaches sufficient concentration, the albumin is thoroughly stirred back into the mass and the mass finally cooled into forms. Mysost is a brown, hard brittle mass consisting principally of caramelized milk-sugar. Analysis shows such percentage composition as follows : water 10 to 20 per cent, protein 10 to 15 per cent, milk-sugar 30 to 55 per cent. Mysost is found in the larger markets of the United States. Primost is an albumin cheese somewhat similar to Ricotte and Mysost. It is made by precipitating the 1 Babcock, S. M., Albumin cheese, Wis. Exp. Sta. Rept. 12 (1895), page 134. 296 THE BOOK OF CHEESE albumin by acid and heat. The main difference is in the firmness of the cheese. This is regulated by drying. 282. Whey butter.^ — The loss of a percentage of fat, rarely less than O.o per cent and in some cheeses very much greater, has led to the making of whey butter. For this purpose a separator is introduced and all whey is separatetl daily. The fat recovered in the form of cream is then ripened and churned. Whey butter is not rated as equal to butter made from whole milk but a fair market can usually be found for the product. The recov- ery of 0.25 per cent fat means two and one-half pounds of fat to 1000 pounds of whey. This will make about three poimds of butter. Whether whey butter shall be made depends on the volume of business, the extra equipment required, the extra help necessary and the market for the product. As a rule, whey butter is economically recoverable only in large factories. It is not considered advisable to attempt to make it unless one has the whey from 10,000 pounds of milk. In some instances, the com- bination of small cheese factories with one churning plant has proved to be economical. The objection to the making of whey butter is, that it stimidates careless- ness on the part of the cheese-maker because he thinks that the fat will be recovered by skimming. lie does not realize that the other milk solids are being reduced in the same proportion as the fat, to the great loss in yield of cheese. 1 Doane, C. F., Whey butter, U. S. Dept. Agr. Bur. An. Ind. Circ. 161, pages 1-7, 1910. Sammis, J. L., Making whey butter at Cheddar cheese fac- tories. Wis. Exp. Sta. Bui. 246, 1915. Ellenberrger, H. B., and M. R. Tolstrup, Skimming whey at Vermont cheese factories, Vt. Dept. Agr. Bui. 26, 1916. CHAPTER XVII CHEESE FACTORY CONSTRUCTION, EQUIPMENT, ORGANIZATION The principal factor in determining the location of a cheese factory is the available supply of milk. This is usually ascertained by making a canvass, and finding out the number of cows whose milk would be brought to the factory. The quantity of milk or the number of cows necessary to insure sufficient milk for the suc- cessful operation of the factory, depends on the variety of cheese to be made. When making types of cheese for which very sweet milk is necessary, the milk must be delivered twice a day. This demand limits the area from which the factory can secure its supply. The length of time the cheeses are held in the curing-room and the work necessary to care for them also limits the area which the factory can ser^'e, because a very large amount of milk cannot be handled when the cheese must be given considerable attention in the curing-rooms. Swiss, Lim- burger and Brick cheese factories usually do not require a large supply of milk ; therefore the factories may be built close together. The size of the Cheddar cheese factories varies but it is generally considered unprofitable to make Cheddar cheese unless there are 5000 pounds of milk available daily. Conditions have changed so that at present different kinds of cheese are made from the 297 298 THE BOOK OF CHEESE surplus milk in market milk plants. In such cases a uni- form supply is not absolutely necessary. The climate must also be suitable for the industry. 283. Locating the site. — In a farming community, several factory sites are usually available. It is best to consider carefully the desirable features of each before trying to make a definite choice. Many of the present cheese factories were located in hollows because it was easy to secure a supply of water, but no thought or attention w^as given to the disposal of the sewage. The following points should be considered in choosing a site : (1) Drainage. — A factory should be so located that it has good drainage. Ground that slopes away from the factory makes the disposal of sewage easy. Sewage should not be allowed to run out on the ground and left to decay, thus forming a breeding place for flies, but should run into a cesspool or septic tank.^ Even in a porous soil, a cesspool frequently clogs and gives trouble. The septic tank seems to be the best method to dispose of the sewage unless the factory is so located that con- nection can be made with a city sewage system. (2) Wafer. — An abundant supply of pure water is essential to a factory. This may come either from deep wells or springs. The value of a never-failing water supply cannot be overestimated. (3) Exyosure. — The factory should be so located that the receiving room is away from the prevailing winds. This prevents dust being blown into the factory. The curing-room should be on the side not exposed to the sun as this will keep it cool. Fig. 59 shows a clean cheese factory of the ordinary type. When it is desirable to cure 1 Farrington, E. H., and G. J. Davis, The disposal of creamery sewage, Wis. Exp. Sta. Bui. 245, 1915. CHEESE FACTORY CONSTRUCTION, ETC. 299 the cheese in a cellar, it is better to locate the factory on the side of a hill. Then the receiving and manufacturing room may be on the ground level and the curing-room, a cellar, back of the manufacturing room and yet all on the same level. This saves carrying the cheese up and down stairs. (4) Accessibility to market should not be overlooked. Often the quality of the cheese is injured by long hauls. Fig. 59. — A cheese factory of neat appearance. An important item in marketing both milk and cheese is the use of the automobile. By its use the products are not so long in transit, and losses from exposure in delivery are reduced. Both milk and cheese, when exposed to the heat of the sun for any length of time, become warm. This gives undesirable organisms chance to develop. 284. The building. — Details of construction or esti- mates of cost will be omitted in the present discussion. A local contractor can do this satisfactorily and also the 300 THE BOOK OF CHEESE cost of materials is constantly changing. Only general considerations as they apply to the manufacture of the product will be taken up. The building may be constructed of wood, stone, various bricks or concrete. The kind of material will depend on the ^elati^'e cost of materials in the local market and on the amount of money available for building. 285. Heating plant. — Many of the older factories have no heating j)lants and some are so poorly constructed that they cannot be warmed. Means of heating should be provided, either by steam or a stove. The loss due to freezing is an item which is entirely avoided in factories properly heated. 286. Curing-rooms. — The size of the curing-rooms will depend on the amount of cheese to be handled and its location on the variety of cheese to be manufactured. In every case, some provision should be made to control humidity and temperature. If the room becomes hot and dry, evaporation from the cheese will be much more rapid. In a hot curing-room, undesirable types of fer- ments are more likely to develop and to injure the quality of the cheese. 287. Light. — The importance of light should be emphasized. It acts as a stimulant to keep things clean. It also makes the factory more cheerful. There should be numerous windows to give plenty of light. A skylight may often serve both as a source of light and ventilation. 288. Ventilation. — Plenty of ventilation should be provided. This may be accomplished by means of the windows or skylight. However, it is a good precaution to have at least one ventilator to carry off the steam and control the circulation of air. All openings should be carefully screened to keep out flies. CHEESE FACTORY CONSTRUCTION, ETC. 301 289. Boiler-room. — The boiler-room should be easily accessible from the manufacturing rooms. A gauge located in the latter should tell the steam pressure. Win- dows or doors should be so located that the flues of the boiler can be cleaned. The coal supply should l)e handy. Great care should be exercised to keep the boiler-room clean for otherwise the dirt will be tracked all over the factory. 290. Whey tanks sliould be kept clean. Daily wash- ing is absolutely necessary to prevent offensive odors. Pasteurization of whey has been found requisite to prevent the spread of disease if raw milk is used.^ This is required by law in some states. It is some- times accomplished by heat with steam coils ; in other cases by running live steam directly into the whey. Whey tanks may be made of wood or steel. The acid of the whey seems to eat and decompose concrete. 291. Store-room. — There should be a separate room or a place in the attic where the sui)plies can be kept. This saves much waste and keeps the factory cleaner and more tidy. 292. The floors. — The floor is the most important part of the building. It should be of non-absorbent ma- terial, which can be easily cleaned, and it should not leak. Concrete makes the best floor of any material used at present. It should slope very gently to the drain. The corners between the floor and side walls should be rounding to make cleaning easy. The drain should be provided with bell traps to prevent the entrance of sewer gas into the factory. If the traps and floor about them are slightly depressed, it will help to make the ' Dotterrer, W. D., and R. S. Breed, Why and how pasteurize dairy by-products, N. Y. (Geneva) Exp. Sta. Bui. 412, 1915. 302 THE BOOK OF CHEESE floor drain more quickly. A catch-basin should be provided just outside the factory for all solid material which might clog the sewer pipe. This should be cleaned three or four times a year. 293. Arrangement of machinery and rooms. — The rooms and machinery should be arranged so that the work AMP \ COVtRtP PR I VE WAV LABORAt i mm WEIGH CAN O -TESTING Shelf- Ok^^SHELF- STarte r can OR barrel o:.. HOT ', WATER • BARREL r^ ^^^„,^ □ PRElSS I .V,,^ TABLES,- □ SEtPARATCiR \, CREAM VAT tllll»»»»l»»»ll»l»>l»l>l»ll>f}f.^,...U , ITT COAL SHEP HIGH WINDOWS FOR FILLlNCi Fig. 60. — A well arranged Cheddar cheese faetory, including the equipment for the nianufactiue of whey butter. will follow the natural sequence of the process with as little inconvenience as possible. Some of the points to be observed in this connection are : vats should be near CHEESE FACTORY CONSTRUCTION, ETC. 303 the weigh-can ; boiler-room near the work room ; cheese presses near the vats ; cheese presses near the curing- rooms and the like. Fig. 60 shows a well arranged Cheddar cheese factory. The necessary machinery and rooms for the manufacture of whey butter are included. In this plan, the attic contains the store-room and the whey tanks. The whey is forced from the vats into the tanks with a steam jet and then runs by gravity to the separator. Slides are provided in the walls of the ice storage to regulate the flow of air into the curing-room and butter refrigerator. In order to have a smaller boiler, a gasolene engine is used to run the separator, churn and curd-mill. The plan can be modified to use the upstairs for a curing-room so that the size of the factory may be reduced. The whey butter could be shifted to a small room where the curing-room now is and the boiier-room added as a " lean-to " at one side of the building. This would materially reduce the size of the main building. Another plan (Fig. 61) shows the arrangement of a Cheddar cheese factory without the whey butter appara- tus. The location of the drain between the vats might be criticized. In Fig. 62 is shown the arrangement of a combined butter and cheese factory. Fig. 63 shows the possible arrangement of a Limburger factory. The size of this factory could be reduced by having the salting tables closer together. In a Cheddar cheese factory, the curing-room may be over the manufacturing room. This makes consid- erable work in carrying the cheese up and down. A small elevator may be used for this purpose. The same principle holds in cheese factories in which other varieties of cheese are made ; the floors should be on one level so 304 THE BOOK OF CHEESE X / / o / CJ / ^ C7 ^ ^ < •^ <^ ,' '^^ N 1 CO "O / ■ C3 « _ / ffl '^ ^ "-I '^^El CO ci CHEESE FACTORY CONSTRUCTION, ETC. 305 far as possible. There is danger of the overhead curing- room becoming too hot and causing the cheese to leak fat. Shelves or tables should be provided on which to 1, Boiler; 2, engine; 3, water pump ; 4, work bench ; 5, wash sink; 6, press; 7, elevator; 8, clieese vats ; 9, separator ; 10, milk heater; 11, milk receiv- ing vat; 12, press; 13, shelf; 14, Babcock tester; 15, weigh- can ; 16, churn; 17, starter; 18, cream ripener and pasteur- izer; 19, refrigerator; 20, milk sheet and sample jar; 21, milk pump. BVTTER. K^m T RECEIVOAiG SCALE: \1\ F-EET Fig. 62. — Combined Cheddar cheese and butter factory. put and keep the utensils. The utensils should never be placed on the floor. 294. Arrangements for cleanliness. — A sink for wash- ing the utensils should be provided and boiling water to scald them after washing. After being scalded, tin utensils dry quickly without rusting. The boiling water 306 THE BOOK OF CHEESE may be obtained by placing a steam pipe in a barrel of water and turning on the steam. The utensils can then be washed clean, dipped in this barrel of boiling water and put in their place. Too much emphasis cannot be laid on keep- ing the factory itself, the utensils and the surroundings clean. This will prevent the development of mold. Cases are known in which the cheese fac- tory was allowed to become very dirty, so that a red mold devel- oped. This eventually got into the cheese and caused red spots.^ They are called rust spots. All doors and windov/s should be screened to keep out flies. 295. Equipment and supplies list. — The J Harding, H. A., and G. A. Smith, Control of rust spots in cheese, N. Y. (Geneva) E.\p. Sta. Bui. 225, 1902. o z lU z to 1 < 2 Ck Ol- 5 in a* < X > u CHEESE FACTORY CONSTRUCTION, ETC. 307 following utensils will be needed in a Cheddar cheese fac- tory to handle 10,000 pounds of milk daily : 1 5-H. P. boiler ; 1 CO-gallon weigh-can ; 1 conductor head and trough ; 1 platform scale ; 1 Babcock tester, glassware and sample bottles ; 2 700-gallon cheese vats ; 2 gang cheese presses ; 1 curd-mill ; 2 curd-knives ; 30 cheese hoops ; 1 whey strainer ; 1 curd scoop ; 1 long-handled dipper ; 1 strainer dipper ; 1 siphon ; 1 cheese knife ; 1 glass graduate ; 1 cheese-trier ; 1 speed knife ; 1 paraffine tank ; 1 Marschall rennet test ; 1 lactometer ; 1 milk can hoist ; 1 acid test ; 1 sink ; 1 40-quart milk can ; 3 pails ; 3 shot-gun cans for starter ; 3 thermometers ; brushes and brooms ; 1 Wisconsin curd test or fruit jars for same ; 1 set counter scales ; 2 curd rakes. If whey butter is made, the equipment should include : Tanks to hold the whey ; separator ; cream ripening vat ; churn ; butter-worker ; butter refrigerator ; large boiler and steam engine or gasolene engine. The following supplies will be needed for the making of the cheese : Bandages ; boxes ; scale boards ; starched , circles ; rennet extract or pepsin ; cheese color ; press cloths ; paraffine ; formalde- hyde ; alkali ; indi- cator ; sulfuric acid. When choosing the utensils, the ease of 1 • J "j. Fig. 64. — A sanitary dipper with a solid cleanmg and sanitary handle, construction should not be overlooked. One of the most unsanitary utensils in a factory is a dipper with a hollow handle. Fig. 64 shows a dipper with a solid handle which any tinsmith can make. The seams of all utensils should be flushed full of solder, to make cleaning easy. When ready to 308 THE BOOK OF CHEESE clean or wash any utensils which have come in contact with milk or its products, the steps are as follows : rinse in cold water, wash in warm water in which some wash- ing-soda has been dissolved, rinse clean, scald in boiling water. Never use a cloth to wash utensils ; a brush is more sanitary. 296. Factory organization. — There are two general classes of organizations^ to operate cheese factories, one the proprietary and the other the cooperative. Un- less the kind of organization is what the dairy-men desire, dissatisfaction is sure to result. (1) Proprietary organization. — Under this form of organization, one person owns and operates the fac- tory. The dairy-men are paid a stated price for milk, or the milk is made into cheese for a stated price a pound. The proprietor receives all profits and assumes all losses. So far as the dairy-man is concerned, the stock com- pany is a proprietary organization. The gains and losses are shared by each member according to the amount of money invested. (2) Cooperative organizatimi. — In a true cooperative cheese factory each patron is an owner, as the name indicates. The object of this organization is to reduce the cost of manufacture rather than pay large dividends, so that the dairy-man with a large herd and small capital invested in the factory obtains more returns than the one who owns considerable capital and has a small herd. Many cheese factories are cooperative in name only and ' Elliott, W. J., Creameries and cheese factories, Mont. Exp. Sta. Bui. 53, 1904. Farrington, E. H., and E. H. Benkendorf, Origination and construction of cheese factories and creameries, Wis. Exp. Sta. Bui. 244, 1915. CHEESE FACTORY CONSTRUCTION, ETC. 309 proprietary in operation. The state of Wisconsin has a law which tends to stop this defect and defines what organizations may use the term or name, cooperative. The constitution of a cooperative organization should state: 1, Name; 2, object; 3, officers and duties of officers ; 4, manager or other person to run business ; 5, capital stock; 6, meetings; 7, voting power; 8, amendments. Some of the most important statements which should appear in the constitution are mentioned in the following sentences. A statement should show what persons are eligible to membership in the organization. It is a careless plan simply to say that the duties of the officers are those usually defined in such an organization. This may lead to confusion and neglect, or both. Direct statements should be made explaining the exact duties of each officer. The limits of the authority of the manager or person who runs the business should be explicitly stated. The manager then knows just what his duties are and what matters or parts of the business must be considered by other officers or committees. The amount of capital stock and the number and value of each share should be exactly stated. The constitution should state when and where the regular meetings must be held and by whom and when special meetings may be called. This gives every member ample notice of the regular meetings. Some method or means should be provided to notify each member of the special meetings. The voting power should be definitely stated, whether it is limited to shares of capital stock or by members or by number of cows owned by each member. It is neces- sary to indicate just how amendments to the constitution may be made. Each member should know before the 310 THE BOOK OF CHEESE final vote just what changes are being proposed. Types of constitutions may be found in the following references : Elliott, W. J., Creameries and cheese factories; organization, building and equipment, Mont. Exp. Sta. Bui. 53, 1904. Farrington, E. H., and G. H. Benkkndorf, Organization and construction of creameries and cheese factories. Wis. Exp. Sta. Bui. 244, J915. Van Slyke, L. L., and C. A. Publow, The science and practice of cheese making, pages 447-453, 1909. Iowa Exp. Sta. Bui. 139, 1913. Creamery organization and construction. CHAPTER XVIII HISTORY AND DEVELOPMENT OF THE CHEESE INDUSTRY IN AMERICA Just when the first cheese was made is not known. By the time the first immigrants came to America, cheese-making was rather generally known in Europe, so that the early settlers brought with them and practiced established methods. The countries of Europe developed different kinds of cheese and have since become noted for such particular varieties, for example : France, Camem- bert and Roquefort ; Switzerland, Swiss cheese ; England, Stilton and Cheddar; Germany, Limburger; Holland, Edam and Gouda ; Italy, Parmesan and its allies, also Gorgonzola cheese. The manufacture of these various cheeses has been attempted in this country. Because of the difference in climatic conditions and in some cases the use of milk of sheep or goats, it was and still is difficult to manufacture some of the European cheeses in America. Since the climatic conditions of this country and certain parts of England are somewhat similar, the manufacture of the cheeses of England predominated, and there was also more information on theii" manufacture. These are probably the reasons why the United States and Canada have become famous for Cheddar cheese. The first cheeses of the Cheddar group were made on the farms. The work was usually performed by women, and the process was very simple. The methods were crude, 311 312 77//'; HOOK or cifEUSE and tlu> clioesos wcmv iiuulo in u more or less liaphazard wjiy. Tlu' milk of the evening was placed in a cheese tub in the dairy room and cooled to a temj)eratnre that would ])revent souring. In most cases the cream that had raised to the surface of the night's milk was removed in the morning. This was considered an act of economy, for it was thought that in the ])rocess of manufacture it would all i)ass off in the whey and he lost. The morn- ing's milk was then mixed with thai of the evening and warmed to the setting temi)erature by placing a portion in a tin pail and suspending it in a kettl(> of hot water. When hot, it was ein|)ti(>d into the tub of cold milk. By transferring back and forth, the setting temperature was hiially r<>acluHl. Few of these settlers owned ther- monu>l(M's. ConseipuMitly, cluH>s(>-mak(M-s were obliged to depend on the sense of fcH'ling to d(>t(M'mine t(Mn])erature. One of the serious difHculties of the ciw\\ manufac- ture was the production of renn(>t of a uniform strength. After the addition of tlu> rennet and as soon as the coagu- lated milk became firin enough, it was broken into as small pieces as could be conveniently made, a wooden knife b(>ing usi^l for the purpose. After standing ten minutes it was stirred by hand, breaking the i)ieces finer, and the temperature was gradually brougiit to 08° F., aiming as near blood heat as could be judged by the sense of fi>cling. It was kept at this temperature until the moisture was out of the curd and it would squeak between the teeth. The whey was drawn oif and the curd stirred until dry, salted and put to press. All the curd of one day was made into a cheese. This resulted in small uneven-sized cheese. Since such cheeses were made from the milk of single dairies with all the surround- ings I'lean, the flavor was usually good but the texture THE CHEESE INDUSTRY IN AMERICA 313 was open and soft. The method of caring for the cheese and marketing was entirely different from that practiced at the present time. All the cheeses made during the entire season were held until fall and marketed at one time. They were packed in casks four to six in a package, one on toj) of the other. The earliest date when single boxed cheeses were on the market was 1841. Between 1820 and 1840, a. small export trade in cheese was started. As this demand for cheese increased, partic- ularly in England, it became necessary to change the methods emi)loyed in manufacture. The farm dairy cheese was rather an open-textured sweet curd product. If not, it was due more to accident than to any intention of the cheese-maker to improve the quality. One of the early complaints from England was that the cheeses were too small and uneven in size. The practice of making I on the farm continued until about 1851, when the factory system was started, although home manufactures con- tinued after that time. Eollowing are the reasons for the change from the farm to factory system: (1) England demanded larger cheese ; (2) the farm product was not uniform ; (3) the quality of the farm cheese did not suit the English trade ; (4) factories saved much labor on the farms; and (r)) could secure higher prices. 297. The factory system. — Where and by whom the first Cheddar cheese factory in America was started is not definitely known. Jesse Williams of Oneida County, New York, is supposed by many to have been the first to build and operate under the factory system, fix 1851. Cheese factories were oj)ene\v ^ Ork and estahhshiul the first Canadian cheese faetory in the town of Norwich, Ontario. It was accepted at once by Canadian fanners, and factory cheese- niakin*;" incrt^ased rapidly. In I Slid, a small cpiantity of cheese was exi)ort(>d and from that time the export trade of Canada has h(>en large and growinj;-. Ontario and (^nehec are now the Icadinj:; i)rovinces in the production of cheese. 299. Introduction of cheddaring. The factories at lirst nsed the same proct>ss as the farms, namely the stirred- curd process. In IS()7, IJoluM't McAdam intioduced the Knglish Cheddar system in a factory near Herkimer, New York, 'i'his is the Cheddar system as known to-day. It ])roduces the closer bodied cheese (lcinand(>(l by the ex[)ort trade. 'I'his introdnction made Herkimer County famous for its cheese. 300. Introduction of Swiss and Limburger. — In 1S7(), factories for I/imbm\i;'cr, Swiss and Hrick cheese were started and haxc j;radually incrt^ascd. In New York such i)lants are located around Boonville in Oneida County, and Theresa, ill JeiVerson County. In Wis- consin, Swiss cheese-making- was begun by a colony of Swiss who came to New Cdarus, (ireen County. It is now^ made in (ireen, Lafayette, Iowa, (irant, Dane and Koek counties. Lind)urg(>r and Brick ari> manufactured in Oodgc", lM)nd dn Lac. Winnebago, Marathon, La (^'osse, Bnllaio, Tr(Mnp(\dean, Clark, \\ashington, l)nnn, Barron and Lincoln conntics. In the southeastern part of Ohio Swiss cheese is produi'cd. Ohio and Wisconsin have 77//'; CIIHH.HM INDUSTIiY IN AMKUK'A 315 maimfjictiircd more of tlicsc cIkh'scs, cspccijiliy Swiss, tliiiii uiiy other stutcs. 'I'liis is j)n)l)iil)Iy due to tlic fact that the ('onditioiis arc more nearly like those of Switzer- land. When the cities in New York he^an to j^row, an increased demand for market milk was felt. I'lic result was that the dairy-men (;ould not supply both the cities and the cheese factories with milk. A lar^e |)art of the cheese was l)eiii^ ex|)orted and most of it had al- ways Ix'cn partly skinuned. The amount of skiimnin^, therefore, was largely increased. Then other animal fats were substituted for the milk-fat. This product was known as "filled" cheese. The delay in con- trolling,' the jiractiee of makiiif; skimmed-milk and filled chees<' ruined the export trade. In ('an;ida laws proliibitcd the m;do o o -t »^' t^' c« C) <-i O T-i o 5 2 2'S Cl CO CI t^ oo H _§i? • O 1 - CO 00 ■*' K^ •a« O Oi 1-H .-H CI O l^ '-0 -f CO ^ -t CO CO r-H e d d C; 05 CO rjj t- S o o -t co' co' -o' Q X t^ t^ t^ O "O '-C ^_^ o cc iO CO of of >< <; -Tf Q 1— 1 i-H .-H 00 't* (Z) GO o g a> 00 lo CI -H ^d M lO t^ »o o 00 m 11 -t O CO CO 'f "TD -H lO O OJ e it CO O 1- CO -H bi ci d d d ^' ^ <: t^ CO --H I-H 1-( 1— ( — 1 Tt4 O '^ t^ O C> O iC OS °2 a OO »0 •* O 00^ 00 2 o ■* o' d' ■*' h-' ^ 00 t^ »0 lO % O O CO Ol^ Tf H aa -t -t i-o' of i-O tH -< <0 01 Ol l-H 't -t O CO 1^ CI ^ X CO CO E3 CO 1- O 'O I-_^ O) |1 2 o aa i.o' co' co' ^ o CO '-0 lO CO o S ." lO ^H 05 "O 05 d d co" of oo' >< <; ^ O) CO ^ Ol ^ -O 'X) CO ^ o t- t^ s fl 1.0 o CO oq CO oo il oo d --H co' of CO 1- oi lo o » i° Ol t- CO^ --H t--.^ >< a a < co' q' of "^ of l-H Q 03 r^ CO CO O X 05 05 lO 0> 00 _g ■^13 C0_^ Ol^ X oo_^ uo •^ 3 -f' co' --H oo' oo' K o 2 C> ^ Tt* 1-1 O 1-H lO CO_^ CO_^ iO a a >< -»; l-H 00 'H ^"' of ■* CJ u H M O CS 320 THE BOOK OF CHEESE of being manufactured into cheese. There is about the same number of milch cows in New York and Wisconsin. However, Wisconsin is credited with more cheese in 1909 than New York ever produced and this output probably will increase, as there are considerable areas of undeveloped agricultural land in Wisconsin. It is also interesting to note that Ohio is falling off in cheese production. This may be due to the increased demand for market milk. On the other hjind, production has increased in Pennsyhania. 304. Exportation and importation of cheese by the United States. — The accompanying table shows the ex- Mil lion s Po und s 300 . n<^ y 250 \ kO< >0^' ,/ r 200 / / 150 0,\ / ^ ^ , /^ 100 / / ^ ^ -1 / \ 50 ^ /' X \ / A ^ X \ ■^L' ^/ '\ — ^ L Jm port s \ / 1850 1860 1870 years 1890 1900 1910 Fig. 67. — Showing relationship of total production, exports and imports of cheese. ports and imports of cheese from 1851 to 1916 and their values, in so far as the figures are available. One noteworthy item in Table XXII is that the exports have gradually decreased and imports increased. This THE CHEESE INDUSTRY IN AMERICA 321 TABLE XXII Showing the Imports and Exports op Cheese by the United States from 1851-1916 Year 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 Imports Amount in pounds 603,398 514,337 874,949 969,417 1,526,942 1,384,272 1,400,252 1.589,066 1,409,420 1.401.161 1.090.835 594,822 545 966 836,127 985,362 1,738,657 2,997,994 6,243,014 6,247,560 Value in dollars Exports Amount in pounds 10,361,189 6,650,420 3,763,932 7,003,974 4,846,568 8,737,029 6,453,072 8,098,527 7,103,323 15,515,799 32,361,428 34,052,678 42,045,054 47,751,329 53,154,318 36,411,985 52,352,127 51,097,203 39,900,367 57,296,327 63,698,867 66,204,025 80,366,540 90,611,077 101,010,853 97,676,264 107,364,666 123,783,736 141,654,474 127,553,907 147,995,614 127,989,782 99,220,467 112,869,575 111,992,990 Value in dollars 322 THE BOOK OF CHEESE TABLE XXII Continued Year Imports Exports Amount in pounds N'alue in dollars Amount in pounds Value in dollars 1880 1887 1888 1889 1890 1891 1892 1893 1894 1895 1890 1897 1898 1899 UXX) IWl 190-2 0.309.124 0.592.192 8.750.185 8.207.021) 9.203.573 8.803.040 8.305.288 10.195,924 8.742.851 10.270.293 10.728.397 12.319.122 10.012.188 11.820.175 13.455,9W 15,329,099 17.007.714 91.877.235 81.255.994 88.008.458 84,999,828 95,370,053 82,133.870 82.UK).221 81.350.923 73.852.134 00.448.421 30.777.291 50.944.017 53.107.280 38.198.753 48.419.353 39,813,517 27,203,184 $2,551,300 S2.745.,597 liH)3 20,071,384 3,183,224 18,987,178 2.250,229 HH)4 22.707,103 3,281,811 23,335.172 2,452,239 1W5 23.095,705 3,379,000 10.134.424 1,084,044 11X)0 27.280.800 4,303.8.30 10.502.451 1,940,020 1^)7 33,848,700 5,704,012 17.285.230 2,012,020 1908 32,530,8;X) 5,580,700 8.439.031 1.092.0.-)3 11X)9 35,548,143 5,800,154 0.822.842 857.091 1910 40,817,524 7,053.570 2,840,709 441.017 1911 45,508,797 7.920.244 10,300,005 1,288.279 1912 40,542,IX)7 8,807.249 0,337,559 898.035 1913 49.387.944 9,185,184 2,599,058 441.180 1914 03.784.313 11,010,093 2,427,577 414.124 1915 50.138.520 9,370.048 55,302,917 8 403.174 1910 30,087,999 7,058,420 44.394,301 7,430,089 is probably because immigrants have demanded the cheeses of their native country which were not made in America. The exports for the years 1915 and 1916 are interesting 77//'; CJIICI'JSK INUUSTItV IN AMERICA 32.3 as they sliovv tlio cflcrt of tlie war ow the chcf^se iiulustry, the imports being gradually decreased and the exports greatly iiif-rcascd. 'J'he graph (Fig. 07; represents the total prorJuftifjn and th(; cxjKjrts and inip<;rts of eheese into th(; l'nit(;d St;itcs. 305. Average yearly price of cheese. TIk; following table shows the average yearly jjrice of Cjheddar cheese in the United States: TABLE XXIII Showing the Avkuaok YEAiiLy Pjuce of Cheese, 1892-1910 Yeab 1S92 w.r.i 1S94 is9<; 1S97 ISOS 1S99 I'M) I l!Kr2 l'K« 1!K)4 1(K).'> HXHi HX)7 VM)H 1W)9 1910 1911 1912 i 1910 Cbntb 9.4 9.4 9.7 9.1 8.4 9.1 8.6 8.6 10.2 9.9 10.1 11.9 lO.r, 10.7 11.7 11.0 12.9 12.6 15.5 12.4 14.2 17.0 17.1 ir,M 10.7 324 THE ROOK OF CHEESE The graph (Fig. (58) shows that the a\'erage yearly price has increased from 9.4 cents a pound to 16.7 cents. 1 a 3 4 5 6 7 8 9 10 11 12 13 14. 15 16 \7 Cents 1892 1895 1900 1905 1910 1915 years Fig. 68. — Average yearly price of cheese. 306. Canadian cheese statistics. — The following statis- tics show the development of the industry in Canada. The figures in Table XXIV show the number of cheese factories, the amount t)f milk received and the total production in Canada. Table XXIV indicates that the number of cheese fac- tories has decreased but that the production has increased. Because of the scarcity of figures, conclusions would not be accurate. The figures in Table XXV of the exports and imports show that the exports gradually decreased and the imports increased. If the production has increased, as shown in Table XXIV, more cheese must be consumed by the 1 T ^^ 1 ,- \ ■-v ^/ ~..^ ~~- _. •*' I " THE CHEESE INDUSTRY IN AMERICA 325 Canadians. The effect of the war is probably seen in the year 1916, when the imports are decreased and the exports increased. TABLE XXIV Showing the Number of Cheese Factories, Amount of Milk Received and the Factory Production of Ch'bese Year Number op Cheese Facto- ries PonNDS OF Milk Delivered Factory Production OF Cheese 1900 1907 1910 1915 1916 220,833,269 204,788,583 199,904,205 183,887,837 192,968,597 2291 1871 1813 1,501,946,221 1,503,997,215 TABLE XXV Showing the Amount and Value of Canadian Exports and Imports of Cheese Year Exports Imports 1880 1890 1900 1910 1911 1912 1913 1914 1915 1916 Amount in pounds 40,368,000 94,260,000 185,984,000 180,859,000 181,895,000 163,450,000 155,216,000 144,478,000 137,601,000 168,961,000 Value in dollars $3,893,000 9,372,212 19,856,324 21,607,692 20,739,507 20,888,818 20,697,000 18,866,000 19,213,000 Amount in pounds 683,778 866,653 919,189 1,495,758 1,512,108 1,162,456 971,821 Value in dollars 82() '/'//a; hook of ciikksk ir (lie ((i|;il |)()|)iil;il ion of (lie I'liilcd SImIcs is li^iircd ,-it KM) million .'irid (he (lillciciicc ltd w ecu (lie cxporls .111(1 iiiipoils roiiiid 1)11(1 iiddcd lo I lie lotid |)r(>(lii('(ioii, ii shows (liii( llic iiAcnip' person nnisl consuinc ;d)ou( (hrco and one-liair |)onnds of cliccsc in a year. In (lie pasi lew years (here has heen considerable de- niatid for more of (lie foreign cheeses, such as Camemhert and {{(xinefort. 307. Introduction of cheese-making into new regions. The mamilacl nre ol < licddar cheese is Ix^iii;;' encom'aj^'ed in new regions, in (he Alle;;hany l\lomi(ains, in \'ir^inia, \Ves( \ ir^'inia, Nordi ('arolina, TtMrnessee and in (he \ves(ern s(a(es. There has also spianifi,' n|) a considerable demand Tor (he lac(ic acid j;roiip of cheeses, especially N(Mircha(el and ('o( (a|i,«', so (ha( while ( he cheese in(liis(ry may decline in cei(ain sec(ions. (he (o(al |)ro(hic(ion will |)n)l)al)ly increase. In (he proper loca(ioiis or see(ioiis, (he cheese indns(ry has a Ncry hri^ld lidnre. The dcxcl- opmen( of ( he skinnncd-milk cheeses will nndoul)(fdly he j;i\('ii considcraMc a((en(ion in (he ne\( lew years. (vKI'-KlllONCKH N. Y. D(>i)(. Ajjfr. Itiil. r>l, 'i'li(> Dairy (iiduslry in New N'oi k StiUc. N. Y. l'n»(iiir(i Ivtu'. nnd Amcriciin I'reaiiiery. Vol. ;M. No. ;<, |)n+re (OS. Vol. :i7, No. ((■>. l)n.K(^ ()S(. V(»[. :{7. No. (»■>, piiKc (>(•)(•». Vol. :{7, No. •.», piiirc (11. Vol. :<:<, No. II, piiijo IS'J. Vo(. :»■., No. '1\\, \n\v:i^ 1()7S. Wis. Kxp. Sdi. 1{(>I>I. IS'.I7, piin<«s \\:\ (('.). U. S. (\misiih. U. S. l)cp». A^,'r. Yt>Mr hooi^s. lliM'(>)iii of Kon>i>;ii iiiul Doiiit'slic ('ommcrci*. SliiMsticjil !il)s(ni('l of (lit* 1 1. S. ('iiiiiKliaii Dt'pl. ;\f^r. (".)(.'">, Ivcpoil ol' llic (!;iiry and cold slonijro (•omiiiissioiH>r. Doiiiiiiioii of t^aJiadii, (\'iisiis and S(alisti('s olli('<>, (vcpl. 1915. CIIAPTRR XTX TI':STIN(J In (•()iiii<'<'li<)ii will) iiiiirkctin^, !i, ccrliiiii nriiounl of testing of llic products should Kc pruclircd, 1o dclcniiinc exactly the results iiiid grades ol" prochuls. This iiichidcs the testing of the whole milk, whey ;iiid elieese for fut, the uiilk for enseiii, ;md the cheese for moisture, in fjictories in which the uiilh is hoiight on the f;il h.-isis, it is necessary to test each |)iitron's milk for hit. If I here is a cheese-moisture law in ihe state, it is necessary to test for inoistun-. 'I'he v\ hey should Ix' tested to learn the loss of fiit in the mjinuhteturing process arid to ascertiiin whether the losses have been rcducc lur lab aiitl total solids. butter and cheese. This is generally called a cream- test bottle. It is graduated from to 50 j)er cent. When testing materials with a small amount of fat such as whey, skim-milk and buttermilk, a test bottle with two necks is used, one with a small bore for the fat and the other neck with a larger bore to add the milk, acid, water. It is graduated from to 0.5 of 1 per cent. There is a third bottle between the other two to test TESTING 329 whole milk. This is known as a whole-milk bottle. It is ^ra(Juate<^l from to 8 per cent. All of the glass- ware should (•omj)ly with the laws. 309. Sampling the milk. — One of the most important parts of testing is to obtain a fair sample of the milk. The milk to be tested may be in a vat or in a farmer's can or a composite sample jar. If the milk is bought on the fat basis, that of each patron is not tested daily, but a small quantity, about half an ounce, is taken each day and placed in a jar ; this is known as a com- posite sample. It is the usual practice to number the patrons and have a sample bottle for each patron with his number on it. Some sul)stance must be added to preserve the milk and to keep it from souring or coagu- lating. It is difficult to secure a fair samj)le of sour milk. A wide-mouthed jar is ])referred for keeping milk samples. This must be kept closed to prevent evaporation. Each day when milk is added to the composite sample, the bottles should be shaken to prevent the cream drying. Composite samples are tested at least twice a month. The milk may be mixed to obtain a fair sample, by stir- ring in the vat or by pcjuring from one bottle to another. Vigorous shaking should be avoided as this is likely to cause churning. One should see that all the cream is removed from the sides of the samj)le bottle and that it is evenly distributed through the milk. The sample of milk is now measured out with the pipette. This is graduated to deliver 18 grams of milk, and holds 17.6 c.c. Hold the pipette between the thumb and second finger of the right hand with the tij) below the surface of the milk, draw the milk by suction with the lips until it is filled well above the graduation. Quickly place the ff)refinger over the opening and at right angles to the pipette. By gently 330 THE BOOK OF CHEESE and carefully raising the forefinger, allow the milk to run down until the surface is exactly level with the gradua- tion. To obtain an accurate reading, the pipette should be on a level with the eye. Then with the left hand, hold the milk test bottle in a slanting position and place the tip of the pipette into it about one-third of an inch and at a slight angle. Now let the milk slowly flow down the side of the neck of the bottle, making certain that none is blown out by the escaping air. When all has run out of the pipette, blow out the drop which remains in the tip. Then measure out another sample in the same way, as the test should be made in duplicate. 310. Adding the acid. — The sulfuric acid should have a specific gravity between 1.82 and 1.83. It should be kept in glass-stoppered bottles or carboys to prevent the absorption of moisture from the air, which will reduce its strength. Acid that is too strong might burn the fat. The acid is a strong poison and will burn if it comes in contact with the flesh or the clothing. In such case, it should be removed by washing with plenty of water. An alkaline substance such as ammonia or bicarbonate of soda should be applied to remove any acid not washed away. The acid measure holds 17.5 c.c. and it should be filled to the graduation. Then this acid should be added to the test bottle. The bottle should be held at an angle and slowly rotated so that the acid will rinse down any milk remain- ing in the neck of the bottle. Immediately mix the acid and milk by whirling the body of the bottle in a circle five or six inches in diameter. The mixture should not be allowed to go into the neck of the bottle while mixing. Continue shaking for about a minute after all the curd has disap- peared. One should avoid pointing the neck of the bottle toward any person in the mixing operation. The acid TESTING . 331 unites with all the milk substances except the fat and generates much heat. 311. Centrifuging. — There are two machines in com- mon use for centrifuging, one that runs by mechanical power and the other smaller and runs by hand. If the machine and atmosphere are very cold, the apparatus can be warmed by placing hot water in it. This is not necessary in a steam machine. In a factory where there are a number of samples to test, a power machine is usually employed. In this machine there are pockets or cups in which to set the test bottles. The machine or disk must be balanced by placing bottles in opposite pockets. These pockets are hinged so that when standing still the bottle is in an upright position and when the centrifuge is running, it is in a horizontal position. The machine should then be covered and started running. It should be run at the speed indicated. After five minutes, stop the machine and fill the bottles with boiling water up to the neck. This can be done without taking the bottles out of the machine. A pipette or slender-spouted vessel may be used to add the water. Whirl the bottles two minutes, then add more boiling water to bring the fat column into the graduated part of the neck of the bottle. Then whirl one minute. The test should be read at once or the bottles kept at a temperature of 130° to 140° F. until ready to read. 312. Reading the test. — To read the test, subtract the reading at the bottom of the fat column from that at the highest point. The curved meniscus which always forms at the top of the fat coluilin should be included in the reading. Duplicate samples should not vary more than 0.2 of 1 per cent. Standard Babcock test bottles and pipettes should always be used. In some states the 332 THE HOOK of cheese agricultunil rxiH-rlmcnt stations oxaminc all glassware and mark it to niako ccTtain tliJit it conforms to tlic ro- (luiixMuonts of tlio state hiw. In New York, <;lasswar(' fonnd to he corroct is branded " S. B.," wliicli means State Brand. In some states a person mnst liaA'e a license to test milk or crc^am, when it is })ai(l for on the fat t(>st. Such a piTson nuist i)ass an examination to show that he understands the test l)efor«> a license will he |)re- sentati\'c sample. The best way, if tlu> entir(> amount caiuiot \)v |)la<(Ml in a \at and stirnMJ, is to catch a little of the whe>' at iuter\als as it is bciui;- drawn from the vat. Tlu> sam])le to hv test(Hi is measuRMl with the pip(>tte tlu> same as the milk and plac(>d in tlu> skiuuned-milk tc^st bottlt\ The same acid is used to test whey as to t(>st milk but because there are not so many solids to destroy, not so nuich is used. If as nuich acid is used with whey as with milk, it will burn the fat and so iut(>rfere with the reading:; of the test. Just enough acid is added to destroy the milk substances except the fat, or enoujih to turn the contents of the test bottle dark brown. This usually recpiircs (illing the acid measure one-quarter of an inch nnd(>r the j^Taduatiou. The remainder of the test is the sam(> as for whol(> milk. 314. Testing cheese for fat. — The sami)le of cheese to test for fat is obtained by removing the sani])le with a cheese-trier. This sample is called a " plug." Dilfereut plugs from the same cheese will test various percentages of fat so that it is diilicult to secure a representative sample. The usual practice is to take three plugs, one TESTING 333 iicjir the center, another iicur the outside and the third between t\n\ first two. TFie plugs slioiild he ]>ut into glass-stopjxTcd bottles to prevent th(! evaporation of rnoistun-. 'i'liese {)lugs are th(;n v\\()\)\)vi\ up very fine. It is of course; impossible; to measure tlu; cheese as with milk and whey, but it is w!iratuH uettcHHury to U'.ni chcoHO foe In!,. After being weighed, it can be dissolvcid in a little sodium hydroxide and poured into tlie bottle. I )iircrent amounts may be used, corrunonly 1^ or (i grams, but b grams is to be })referred. This is i)la(;ed in the JJabcock cream bottle since there will usually be more fat than can be read in a milk bottle. After the material has been j)lac(;d in the test bottle, about two-thirds of an acid-measure of warm water is add(;d to assist in dissolving the cheese;. The aeicJ is added the same as with the milk. If all 334 THE BOOK OF CHEESE the cheese particles are not destroyed, and therefore do not disappear, a Httle more acid will complete the solu- tion. Centrifuging is performed as with the milk. 315. Reading the test. — In a cream-test bottle the neck is so much wider that there is a much larger meniscus. In order to obtain an accurate result, the meniscus should be removed. This is done by carefully adding a substance called glymol, which is a mineral oil colored red. Usually about one-quarter of an inch of glymol is added to the fat column. This should not mix with the fat. The bottles should be placed in a hot water bath 135° to 140° F. for four minutes before reading. The temperature at reading should be 135° to 140° F. The reading is then taken from the bottom of the fat column to the line between this and the glymol. The bottle is graduated for 18 grams of material, but as only a part of IS grams of cheese was used for the test, the reading should be multiplied by the part of 18 grams used. For example, suppose G grams of cheese were used and the test read 12 per cent fat. Since G is one third of 18, the actual percentage of fat is 3 times 12, or 3G per cent. 316. The Hart ^ casein test was devised to determine the percentage of casein in milk. A special test bottle and centrifuge are necessary. The method of making the test is as follows : Place 2 c.c. of chloroform in the casein test tube, add 20 c.c. of a 0.25 of 1 per cent solution of acetic acid at a temperature of G5° to 75° F. This solution of acetic acid is made by dilut- ing 10 c.c of glacial acetic acid with 100 c.c. of water, then dilute 25 c.c. of this solution to 1000 c.c. with water ; 5 c.c. of milk at a temperature of 05° to 75° F. is then run ^ Hart, E. B., A simple test for casein in milk and its relation to the dairy industry, Wis. Exp. Sta. Bui. 15G, pages 1-22, 1907. TESTING 335 into the bottle. The bottle is then covered with the thumb and inverted and the mixture shaken vigorously for exactly twenty seconds. It is then centri- fuged within twenty minutes at a speed of 2000 revolutions a minute. The bottle should stand ten minutes before reading the per- centage of casein. There are other tests for casein but they are very complicated. 317. Solids in the milk. — Because not only the fat but all the solids are utilized in cheese- making, it is important to know the amount of the solids in the milk. This is ascertained by determining the specific gravity of the milk and knowing the fat-content ; the solids not fat can then be calculated. 318. The lactometer. — The specific gravity of liquids is measured by an instrument called a hydrometer. Its use is based on the fact that when a solid body floats in a liquid, it displaces a volume of liquid equal in weight to its own. Hydrometers are in many cases so made that the specific gravity can be read at the point where the scale is even with the upper surface of the liquid. A hydrometer that is especially adapted to milk is called a lactometer. There are two lac- tometers in common use, the Quevenne and the Board of Health. The Quevenne lactometer. — This is a long slender hollow piece of glass weighted at the bottom to make it float in the milk in an upright position (Fig. 71) . The upper end is slender and contains the scale. This scale is graduated from 15 at the top to 40 at the Fig. 71. — a Quevenne lactometer. 336 THE BOOK OF CHEESE bottom. Each reading on the scale corresponds to the point marked specific gra^'ity on a hydrometer, except that the figures are not complete. For example, 15 on the Quevenne scale means a specific gravity of 1.015; a reading of oO on the Quevenne scale means a specific gravity of 1 .0)^0, and so on. The Quevenne lactometer is graduated to give correct results at a temperature of 60° F. The milk should be at this temper- ature. If the temperature is below or above this, a correction nuist be made to the read- ing. The temperature should not be more than 10 degrees above or b{>low 60° F. The correction for each degree in ^■ariation of tem- perature can be made by adding 0.1 or sub- tracting 0.1 from the lactometer reading, as the case may be. If the temi)erature is above G0° F., the correction is added to the lactom- eter and if it is below 60° F., the correction is subtracted from the lactometer reading. The reading should be taken when the lac- tometer is floating free in the milk. The scale is read exactly at the surface of tiie milk. The better lactometers have a thermometer with the scale just above or opposite the lactometer scale. The Board of Health lactometer. — This is very similar to the Que\enne lactometer Health lac- exccj^t that the scale is graduated from to tometcr. j^o (Fig. 72). The point on the scale of the lactometer that floats at the surface in water is represented by 0, and 100 represents the specific gravity of 1.029. On the Board of Health lactometer, the 100 degrees or divi- TESTING 337 sioiis from to 100 equal 29 divisions on the Quevenne. TlieiTl'ore, one division on the IJoard of Health equals 0.29 of a division on the Quevenne. To convert Board of Health reading to Quevenne, multiply by 0.29 and to convert Quevenne to Board of Health, divide by 0.29. The correction for temperatures above or below 00° F. is made the same as with the Quevenne, except 0..'^) is added or subtracted from the reafling instead of 0.1 as with the (Quevenne. 319. Calculating the solids not fat in the milk. — When the lactometer readiufi; and fat-content of the milk are known, there are several formulas for calculating,' the solids not fat. In the following formulas, L equals Que- venne lactometer reading at ()0° F., and F equals the percentage of fat in the milk : = S.N.F. 4 - + 0.2 F + 0.14 = S.N.F. 4 320. Testing cheese for moisture.' — There are two methods of testing cheese for moisture. The following is a simple test devised by II. C. Troy : The ordinary butter moisture test, in which a metal cup is heated over a flame, cannot be used for determining the percentage of water in cheese because the high tem- perature developed in operating that test drives from 1 Sammis, J. L., Tho moisture test in the cheese factory, Wis. Kxp. Sta. Circ. 81, 1<)17. Troy, H. C, A chisese moisture test, N. Y. (Cornell) Exp. Sta. Ext. Bui. 17, 1917. 338 THE BOOK OF CHEESE the cheese other substances with the water. Also, par- ticles are lost by spattering when the cheese is heated with any degree of rapidity in the shallow butter-moisture cups. To overcome these difficulties, the new method here described has been developed for the purpose of determining the percentage of moisture in cheese. The a})})aratus consists of : 1 double-walled coj)per drying cu]) 1 centigrade thermometer registering to 200° 1 alcohol lamp 1 tripod 1 special flask 1 scales sensitive to 0.01 gram I set t)f weights, 0.01 to 100 grams The bt)dy of the co])])cr drying cup may be made in two parts. One of the i)arts is a jacket that forms the outer wall of the apparatus. It has a flat bottom 4| inches in diameter, and the i)er])endicular wall is 4| inches in height. The inner part of the cup must have a flat bottom 2f inches in diameter and a side wall 3^ inches high. A flange attached to the upper rim of the inner ])art extends out at right angles to the cuj) wall and forms a cover for the space bet\\(>en the walls when the two parts are put together. The flange is IxMit down around its outer edge to make it fit snugly ()\er the ui)i)er rim of the outer jacket. It thus holds the inner cup securely in ])lace, leaving a s])ace about } inch wide for oil between the walls and bottoms, and ])ermits the apparatus to be taken a])art readily. A circular o])ening about I inch in diameter is made through the flange to permit the insertion of a thermometer for taking the temperature of the oil or the melted fat which is used in TESTING 339 the space between the walls. Lartl or tallow serves best for use in this space ; a readily inflammable oil should not be employed. The thermometer may be permanently held in place by passing it simgly through a hole bored in a cork, the cork being then fitted into the hole through the flange. A flat metal cover is placed on the cup when making a test. This cover has a hole through the center just large enough to permit the neck of the drying flask to extend up through it. The cover assists in keeping the body of the flask at a constant temperature by preventing the entrance of cold air currents. The thermometer should register changes in temperature between zero and 200° C. The alcohol lamp should yield a flame about \ inch in diameter and f inch high. The tripod should be about 6 inches high and of proper diam- eter at the top to support the oil bath. An ordinary flat-bottom glass Erlenmeyer flask, of such a diameter as to fit neatly into the oil-bath cup, may be used to hold the cheese during the drying operation ; but a special glass flask serves better. It is made with a flat bottom 2}^ inches in diameter, which will fit into the cup of the drying apparatus. The side walls of this flask should be perpendicular for about 1 inch, when they should begin to slope in toward the base of the neck, which should be located about 2 inches above the bottom. The neck of the flask should be 1 inch in diam- eter, with perpendicular walls, and its length should give the flask a total height of 4f inches. When the apparatus (Fig. 73) is put together for the first time, the melted fat or oil may be placed in the outer jacket and the inner cup may then be fitted into position, or the parts may be put together first and the oil then poured into the space between the cup walls through the opening where 340 THE BOOK OF CHEESE the thermometer is to be placed. The oil should fill the space to within an inch of the top. The cork through which the thermometer has been passed is then fitted into the opening. The thermometer bulb should be placed in the oil about half an inch above the bottom of the outer jacket. The apparatus is then placed on the Fig. 73. — Apparatus necessary to test cheese for moisture. tripod over the alcohol lamp. A flame | inch in diameter and f inch high will give sufficient heat to hold the bath at the proper temperature. The temperature may be regulated by raising or lowering the lamp or by changing the size of the flame by adjusting the wick. Hundreds of tests may be run without taking the apparatus apart TESTING 341 or changing the oil. The copper drying cup can be made by any tinsmith. The other parts may be ordered through any dairy or chemical supply company. 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 representative sample of the cheese, which may be taken with a cheese-trier and held in a glass-stoppered sample jar, is then cut into particles about the size of kernels of wheat without removing it from the jar. This may be accomplished 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 in the preparation of the sample. With the thermometer in the oil bath registering 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 ap- paratus. The flask should remain in the bath for fifty minutes, the temperature being kept between 140° and 145° C. all 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 was heated until the water contained in it was evaporated. The remaining substance weighed 3.15 grams. What percentage of water did the cheese contain? 342 THE BOOK OF CHEESE Answer: 5.00 - 3.15 = 1.S5 1.85 -^ 5 = 0.37 0.37 X 100 = 37 (percentage of water in cheese) A butter-moisture scales with an extra 5-gram weight may be used for vveigliing out the 5 grams of cheese. If the scales indicates the amount of moisture in 10 grams of butter by jxTcentage graduations on its beam or by percentage weights, then it will be necessary to nniltiply by 2 the i)crcentage indicated by such scales or percentage weights when only 5 grams of cheese is used. Tlie moisture may be determined by weighing out a small sample of cheese and drying it in an oven and calling the loss moisture. Many such ovens have been devised. New York and Wisconsin have laws limiting the amount of water which may be incori)oratcd in (^hed- dar cheese. New York places the limit at 39 per cent and Wisconsin at 40 per cent. If the moisture-content is above this, the cheese must be branded adulterated. CHAPTER XX MARKETING Marketing is related to cheese in two ways : First, the j)urchase of the raw material, the milk ; and secondly the sale of the finished ])roduet, the cheese. 321. Buying milk. — The method of paying for the milk dift'ers in the various cheese sections and factories. At some factories a stated j)ri('e is paid for the milk or the fat. This is usually in terms of 100 pounds of milk or for each pound of fat. This is the practice with concerns possessing large capital. Other factories make the milk into cheese and after each sale, the expenses necessary for operating the factory are deducted and the remainder of the money divided among the patrons. This money is divided either on the basis of the rmmber of pounds of milk or of fat delivered. The ques- tion arises as to which is the better method to buy milk for cheese-making, or the fairest way to divide the money received from a sale of cheese. 322. Cheese jdeld basis of buying milk. — Let us sup- pose that at a cheese factory there were five patrons: (A) delivered 100 pounds of milk testing 3 per cent fat ; (B) 100 pounds of milk testing 3.5 per cent fat ; (C) 100 pounds of milk testing 4.0 per cent fat ; (D) 100 pounds of milk testing 4.5 per cent fat ; and (E) 100 pounds of milk testing 5.0 per cent fat. Table XXVI shows the 343 344 THK HOOK OF ClIKKSE actual number of pounds of clieoso containing 37 per cent moisture wiiicli 100 j)oun(ls of milk containing difi'erent percentages of fat will jiroduce. The cheese sold net for 20 cents a pound. TABLE XXVI Showing Payments foh Milk Bahkd on the Actual Yield OK Cm KIOSK Patron Pounds OP Milk Dblivicred Per Cent op Fat in Milk Yield op Cheese Con- tainino 37 % Moisture Price a Pound Amount Due Each Patkon A H r I) 100 100 100 100 100 3.0 3.5 4.0 4.5 5.0 8.30 9.45 lO.OO 11.74 12.U0 $.20 .20 .20 .20 .20 .mi. ()(■). 1 .89 2.12 2.348 2.58 Total 500 20 52.90 . .20 10.598 This table shows the amount of money each patron should receive if the money were dividctl on the basis of the actual yield of cheese. 323. Fat basis for payment of milk. — Let us suppose that the same five patrons delivered the same quantity of milk testing the same percentages of fat and that the cheese sold for the same price. A total of 20 pounds of fat was delivered and the cheese sold for $10,598 ; by divid- ing this amount by tlic pounds of fat delivered, the price or value of one pound of fat is found to be $.5299. Multi- plying the pounds of fat each patron delivered by the price a pound would give the amount of money dUe each l)atron. MARKETING 345 TABLE XXVII SHowiNfi Paymb:nts for Milk Based on Fat-contknt of Milk Patron I'OUNDS <)!•' Milk Delivered Per Cent OP Fat in Milk Pounds or Fat Delivered Value ok Pound of Fat Amount Dub Each Patron A B C D E 100 100 100 100 100 3.0 3.5 4.0 4.5 5.0 3.0 3.5 4.0 4.5 5.0 .1.5299 .5299 ..5299 ..5299 ..5299 .11. .58 1.85 2.12 2.38 2.65 324. Weight basis or pooling method for payment of milk. — By this system, ciicli j)atr<)n would r('ct'iv(> iiri equal price for 100 ])()Uii(ls of milk. If the same supposi- tion is taken us before, there would be 500 i)ounds of milk delivered and the cheese sold for .1i)10..59; each 100 pounds of milk would be worth $2.12. As each i)atron delivered an ecjual weight of milk, each would receive an equal amount of money, or .$2.12. 325. Fat-plus-two method for payment of milk. — Some workers have thought that by adding two to the fat test, the division of money would l)e more nearly the true cheese-i)roduci(ig value of the milk. The amount due each j)atroii is figured as in the fat basis, except that two is added to the fat test and this is used as the basis of division. If the same supjxjsitions were used as before, each patron would receive the anujunt shown in Table XXVIII. 326. Comparison of methods. — Th(> best way to judge the dillerent methods of pacing for milk is to compare them with the true value based on the actual cheese yield as shown in Table XXIX. 346 THE BOOK OF CHEESE TABLK XXVI II Showin(! P.wmknts von Milk uv K.vi'-ri-i's-'rwit Mirnions Patron Pounds ''of Milk Dklivehkd Per Cent of Fat in Milk Fat Plus Two Pounds OF Fat DuLIVERlilD Value of Pound op Fat Amount Due Kaoh Patron A 100 :?.() 5.0 5.0 .1i;.:^5;i $1.70 n 100 ;?.r) 5.5 5.5 .:}5:i 1.01 r 1(H) •l.O ti.O 0.0 .;i5;? 2.12 1) 100 1.") (5.5 0.5 :Ar>A 2.2«) 1^: 100 ").() 7.0 7.0 .;}5:i 2.47 T.VULK .\.\1\ SnOWINO THE C0MP.\R1S()N Ol'' 'I'lllO DiFFKUKNT M KTIK^OS OF PaYINU for MiIjK at (^IlKKSIO F.\("rC)UIKS Patron Percentaok OF l''A'r IN Milk Error in Payment per 100 Pounds op Milk by I'oolinK System + $0.4li + 0.2.S 0.(H) - 0.2;} - 0.4G Fat Basis Fat-PI US-Two Method A B C D E ;{.5 1.0 ■1.5 5.0 - $o.os - 0.01 0.00 + 0.04 + O.OcS f $0.10 + 0.05 0.00 - 0.05 - 0.10 A careful study of the above table shows that the pool- ing system is in favor of the (liury-iuaii with the poor milk, and that the fat basis favors tlie dairy-man with the ricli milk. This is (hie, of course, to the fact that the casein does not in(T(>;is(> in tht> milk (piite in jjroportion to the fat. With tlu> pooline,' system or fat basis of i)ay- ment, no account is taken of th(> casiMu ; but tlu> fat-plus- two system is an attemj)t to recoj;ni/,e i\\v casein, but considers the percentage of casein in all milk to be the MARKET/ Na 347 same. This method is in i'iivor of the am contaminated by being kept in stables containing cattle or other animals, or cream to which has been added or into which has been intro- duced any coloring matter or chemic^al or preservative or dele- terious or filthy substance or any foreign substance whatsoever, or cream in any stage of putrefaction, provided, that nothing in this act shall be construed to prohibit the sale of pasteurized milk or cream to which viseogen or sucrate of lime has been added solely for the purpose of restoring the viscosity, if the same be distinctly labeled in such manner as to advise the purchaser of its true character ; and jiroviding that nothing in this act shall be construed as prohibiting the sale of milk commonly known as ' skimmeil milk,' when the same is sold as and for ' skimmed milk.' Milk drawn from cows within eight days before or four days after parturition, or milk to which has been added or into which has been introduced any coloring matter or chemical or preservative or deleterious or filthy substance, or milk drawn from cows kept in a filthy or unclean condition, or MARKETING 349 milk drawn from any siok or disoasod cow or cow having!; ulcers or oth(!r runninf^ Kor(;.s, or milk drawn from cows fed unwhole- some food, or milk contaminated by \nAn\x, kept in stables con- taininf? cattle or other animals and cream from any such milk, or cream in any stafi;e of putrefaction are hss;iry. 'I^lic fee for inspection siiiill Ito lil'ty (TK)) (HUits for lots coiisist-inti; of lil'ty (fK)) box(»s or less. Lots (>x('('('(liM},' lil'ly (50) boxers siiiill !»»> oiui ckmiL por box, wlii(^li .shall b(i coIIccIihI I'l-oin iho iiuMnlx^r onUiriiiji: llio inspection. Kiile 11. Tlu^ Chooso luspcH'-lor's cortilicato shall bo luado to read as follows : NKW YOliK MKIU^ANTIIJO K.\(M1AN(3K Cheese I itsixrlorH (U'rlijicnlc lnsp(Hition No This is to certify that 1 luive this day inspected for M i\w I'ollowiiifj; cliec^se, now localiMJ at Factory and identilication marks „ (^naiitily in lot boxes (,)iiantity insp(>ctod boxes and lind as follows : Klavor Mody and Textnre (^olor (Condition Boxes , Grade Inspection cliarf;(>s .._ liisjicrlor The c(>rtilicat(' to liaxc a blank niar^,in of three incli(>s at the bottom, for the i)iiri)os(^ of ins(>rtinf^ sptvMru^ations of Institu- tions, also for cheesci sold und(>r tJie Call, so that, the Inspector may certify that cheese insfx-ctcd till I he reipiireinents as sp(H'.i(ied NKW YORK Ml<;i{(\\N^rihh; K.XCllANdK Oh'KlCI Al, 1 NSl'KCnON Number Date Inspector and the Tnspocdor shall brand one impression on both boxes and cheese. \l\i\o IC). The Weifjfher's (^crtilicale shall be made to read as follows : MAHKKTINd 355 This is to f'.crf ify that tlic followirij^ is tlio a(!tual tost of boxes, out of sliiprrKUit of hoxcis F'aotory Mark MarkcHl Woif,'hts Actual Weights Loss Av(!ra}^o loss lbs. on box<(S Now York 19 Weigher and tli(! Cho(!so Rulos numbloiMnents are now taking place in the mountain areas of the South, notably North Carolina and adjacent states, and in several centers of the western mountain states. INIany other areas should develop the making of cheese in some form. ^Hibbard, B. H., and Asher Hobson, Markets and prices of Wisconsin cheese, Wis. Exp. Sta. Bui. 251, 1915, MARKETING 359 The actual costs of making and scllinj? cheese were found })y the Wisconsin in\'estif:;ators to vary approxi- mately as follows: (1) cost of rnakinf^, 1.2 to 1.75 cents; (2) storage, | cent a pound a month, or ^ to ^ fcnt for the season ; {'.\) transportation to distant points, $.20 to .11)2.50 for 100 pounds according to distance ; (4) the local dealer, about 1 cent a pound ; (5) the wholesale dealer, 2 cents ; (6) the jobber or broker who occasionally intervenes, about i to J cent ; and the retailer, 5.5 to 9 cents. The entire cost of selling at the time this investigation was made represented about one-half of the retail price of the cheese. The producer of milk received the other half of that j)rice. 332. Standards. — Legal standards in the United States are thus far largely based on the specifications of American Cheddar. In so far as they are applied to other products, they operate merely to i)revent or reduce the use of skimmed-milk. The analyses and limits pro- posed in the discussion of varieties or groups in this book represent the range of composition actually known to be associated with cheeses of typical quality. Efforts are now being made to establish definitions and standards of composition which will limit the use of cheese names to products conforming to the requirements for such varieties. Practically the only federal requirement thus far enforced in the United States is that 50 per cent of the water-free substance of the cheese must be milk-fat. Various states have local requirements but most of them include the federal rule as to fat. New York and Wisconsin now restrict the amount of water in Cheddar cheese to 40 per cent. Most states have laws regulating the manufacture and sale of skimmed- milk cheese. 360 THE BOOK OF CHEESE 333. Laws relating to cheese marketing. — A cheese of foreign origin if made in this country must be branded to show that it is not imported. For example, Camem- bert made in America is labeled Domestic Camembert. Some manufacturers call it Camembert type of cheese. The same applies to other varieties of foreign cheese. If a variety is made under a trade-marked name, this prevents any other manufacturer from using that name. For example,, a concern may make "Philadelphia" cream cheese ; other concerns may make cream cheese, but they must call it by some other name. The committee on definitions and standards for the Association of Official Agricultural Chemists has now un- dertaken to define the proper use of type names. This is intended to determine the proper limits of composition of cheeses in each variety and such essentials of physical identification as will insure the proper use of these names. Certain states have laws which relate to the branding of the cheese to denote quality. If the cheese is made from whole milk, a brand may be applied to show this fact. This is usually called the state brand. If made from skimmed-milk, the cheese must be branded to show this. The following ^ illustrate the laws relating to the state brand and skimmed-milk cheese : See. 48. Manufacturer's brand of cheese. " Every manu- facturer of whole-milk cheese may put a brand or label upon such cheese indicating ' whole-milk cheese ' and the date of the month and year when made ; and no person shall use such a brand or label upon any cheese made from milk from which any of the cream has been taken. The Commissioner of Agri- culture shall procure and issue to the cheese manufacturers of the state, on proper application therefor, and under such regu- lations as to the custody and use thereof as he may prescribe, 1 N. Y. Agricultural Laws, Sect. 3, paragraphs 48 and 49. MARKETING 361 a uniform stencil brand or labels bearing a suitable device or motto, and the words ' New York state whole-milk cheese.' Every suc^ brand or label shall be used upon the outside of the cheese and shall bear a different number for each separate fac- tory. The commissioner shall keep a book, in which shall be registered the name, location and number of each manufactory using the brands or labels, and the name or names of the persons at each manufactory authorized to use the same. No such brand or labels shall be used upon any other than whole-milk cheese or packages containing the same. (As amended by chap- ter 207 of the Laws of 1910.) Sec. 49. Use of false brand prohibited ; branding of skim- milk cheese regulated. No person shall offer, sell or expose for sale, in any package, butter or cheese which is falsely branded or labeled. No person shall sell, offer or expose for sale cheese commonly known as Cheddar cheese made from skimmed or partially skimmed milk unless the same is branded to show that it is skim-milk cheese. All such cheese so sold, offered or ex- posed for sale shall be branded with the words ' skim-milk cheese,' or if such cheese contains thirteen per centum of milk fat or over, it may be branded ' medium skim-milk cheese,' or if it contains eighteen per centum of milk fat or over, it may be branded 'special skim-milk cheese.' Such branding shall be upon the sides of both the sheese and the container. The branding herein provided shall be in block letters at least one-half an inch square. (As amended by chapter 456 of the Laws of 1913.)'! Filled cheeses are those from which the milk-fat has been removed and other animal fats substituted. The laws of some states prohibit the manufacture of this product. The federal law relating to filled cheese permits its manu- facture under license, taxes and government inspection. The various states have laws regulating the length of time that the cheese may be held in cold storage. Another important law in some states requires the cheese-maker to have a license. He must pass an examination to show that the principles and practices of cheese-making are understood. CHAPTER XXI CHEESE IN THE HOUSEHOLD Although cheese in some form is familiar to every household, it has been widely regarded in America as an accessory, almost a condimental substance rather than as a staple food worthy of comparison with meat or eggs. Statistics of the annual production, importation and ex- portation of cheese indicate that the total consumption in the United States is about 300,000,000 pounds — per- haps three pounds per capita. The household manu- facture and consumption of cottage cheese would add a small amount to these figures. Cheese is used as a staple source of food values among many peoples of Europe. Such use of cheese increases rather than decreases with the density of the population. France with a small fraction of the land area and one-half the population of the United States produces and con- sumes about the same amount of cheese. In America, cheese-making has been developed with the advance of settlement into unoccupied territories only to be dropped as increasing population produced greater demands for milk in other forms. If cheese had been accepted as a regular part of the food supply in such communities, some form of cheese-making would have survived the economic changes. 334. Food value of cheese. — A consideratic*i of the nutritive components of cheese shows it to be a rich 362 CHEESE IN THE HOUSEHOLD 363 source of fat, protein or both, according to the variety under examination. It is low in carbohydrates, and aside from salt (sodium chloride) compares favorably with other substances in mineral constituents. The following discussion with an amplified table is taken from Langworthy and Hunt : ^ ** In order, however, that the question of the use of cheese in the diet may be adequately discussed, knowl- edge of its composition in comparison with other foods is desirable, and there is an abundance of data available on this subject, since the composition of cheese and other foods has often been investigated at the Department of Agriculture, in experiment station laboratories and in many other places where nutrition problems are studied. An extended summary of analyses of cheese of different sorts is included in an earlier publication of this depart- ment.^ " Data regarding the composition of cheese and a few other common foods are summarized in the following table. " It will be seen from the table (Table XXX) that cheese has nearly twice as much protein, weight for weight, as beef of average composition as purchased and that its fuel value is more than twice as great. It contains over 25 per cent more protein than the same weight of porterhouse steak as purchased, and nearly twice as much fat. " As shown by the figures in the following table, cheese contains 3.8 per cent ash. Of this a considerable part may be salt added in cheese-making. Like the milk from which it is made, cheese ash is characterized chiefly ^ Langworthy, C. F., and C. L. Hunt, Cheese and its eco- nomical uses in the diet, U. S. Dept. Agr. Farmers' Bui. 487, 1912. 2 See also, Reich, R., Cheese as a food and its judgment from standpoint of the food chemist. Arch. f. Hyg. 80 (1913), no. 1/6, pages 1G9-195. 364 THE BOOK OF CHEESE Q O ^ o ^^ 2 <« S o o o« "^ S O fc a ° m W W O ' b O O 1 0" II tj •-) 4" * B 2 S Q w ooooor^»o;oioc^t^o0i000 '? ioco^^t^oa5co(N'-H.-i05ooo30i g J H p _o 05_ 05 i-H --H C^__ fO^ t^ O I> CO Cq_ -I--HGO '--H ■--< "r-J §S '^ 1 q ^ i> TjH 00 (M_ §5 ^ c^ lO CO TJH GO d ■<* lO 1— 1 T-H 1— 1 1— 1 H r-.iOG005'*'*C5coioqco^^coio fa ^ coioaot^dddoid'*''-H CO 1-H »-H r-H (M (M 1— 1^ O ^ (M_(N00--;O2iO^^TrcO(NG0(NC0rt; K 5 s5 iOLOo6d'-Hcodcococod'-H(N fc H C^q^^,_i(MO'i(>q,-Hr-l iMiO(M^OODI>iOt^pcO<©COOCO 5 ^ Tt^dl^i<^id■'*colOc6^^ld(^^o6coTl^ ^ CO>^OiOCOiO>OCOt^COCOCOt^cDOO IS D CO t>. (>i q o 1 ^ QO C^ ,-H d lO I-H 1-H '"' :) ■^ d o 'D o o cS O J3 O -S '=' •n M-^ t^-^ g -a '-iS S '^-l W -I-H Sys^^tH-^ «tH c^ ft^ft IB QJ eg ® oJ'gS-SS-g'^^S -^s^^^^ c )« PL, h- 3P W ^ fc Ph <; II CHEESE IN THE HOUSEHOLD 365 by the presence of calcium (lime), magnesium, phosphorus and iron, the average values as given in earlier bulletins of the department^ being 1.24 per cent calcium oxid, 0.049 per cent magnesium oxid, 1.49 per cent phosphorus pentoxid, and 0.0015 per cent iron." It is clear from the calculations shown in the last column, that Cheddar cheese takes first rank among the foods compared as to fuel value. The estimate of food values in terms of calories may not completely express the value of that food to a particular individual. It is generally conceded that one great function of food is the production of energy and this function is probably more closely determined by the number of calories produced than in any other known way. Such calculation has become an essential factor in the preparation of dietaries. The calculation here given necessarily applies only to Cheddar cheese. By easy use of the last column, the caloric value of this cheese can be compared with that of any competing food and the relative economy determined, whatever the price asked. Another recent calculation with reference ^ to the same cheese follows : " One pound of American Cheddar cheese contains as much protein as — 1.57 pounds of sirloin steak. 1.35 pounds of round steak. 1.89 pounds of fowl. 1.79 pounds of smoked ham. 1.81 pounds of fresh ham. " In order to judge the value of foods fairly not only the protein but the energy also must be compared. To supply 1 Doane, C. F., and H. W. Lawson, Varieties of cheese, U. S. Dept. Agr. Bur. An. Ind. Bui. 146. 2U. S. Dept. Agr. Bur. An. Ind., Dairy Div. A. I. 21, 1917. 366 THE BOOK OF CHEESE energy cheese is one of the best of food products. On the basis of energy supplied, 1 pound of cheese equals — 1.98 pounds of sirloin steak. 2.61 pounds of round steak. 2.52 pounds of fowl. 1.17 pounds of smoked ham. 1.29 pounds of fresh ham." All these discussions have applied to whole-milk Ched- dar cheese. With minor reductions, much the same fig- ures will hold for Swiss, Limburger, Brick, Munster, Edam. On the other hand, very little has been published until recently on the skimmed-milk cheeses. The food value lost in skimmed-milk has at times been enormous. Many households purchase milk by the bottle, use the top-milk as cream and lose a part of the remainder. Similarly creameries have wasted tons of skimmed-milk. The re- covery of the protein of this milk for human food is both good economy and an important addition to the dietary. The United States Department of Agriculture has recently published the following : " Cottage cheese is richer in protein than most meats and is very much cheaper. Every pound contains more than three ounces of protein, the source of nitrogen for body building. It is a valuable source of energy also, though not so high as foods with more fat. It follows that its value in this respect can be greatly increased by serving it with cream, as is so commonly done." It is an open question whether the decline of cheese- making in America is not due to our failure to develop the use of skim and part-skim cheeses. The whole-milk cheeses are very rich in fat. Use of such cheese in quan- tity in connection with ordinary foods quickly leads to the CHEESE IN THE HOUSEHOLD 367 ingestion of too much fat. The skimmed-milk cheeses are primarily protein food and as such substitutes for lean meat. " The following table shows that cottage cheese is much cheaper than most meats in furnishing protein for the diet. " For supplying protein, one pound of cottage cheese equals : 1.27 pounds sirloin steak. 1.09 pounds round steak. 1.37 pounds chuck rib beef. 1.52 pounds fowl. 1.46 pounds fresh ham. 1.44 pounds smoked ham. 1.58 pounds loin pork chop. 1.31 pounds hind leg of lamb. 1.37 pounds breast of veal. " In addition to protein, energy for performing body work must be furnished by food. As a source of energy also, cottage cheese is cheaper than most meats at present prices. The following table shows the comparison when energy is considered. " On the basis of energy supplied, one pound of cottage cheese equals : 8| ounces sirloin steak. 11 J ounces round steak, llj ounces chuck rib beef. lOf ounces fowl. SJ ounces fresh ham. ' 5 ounces smoked ham. 6 ounces loin pork chop. 7| ounces hind leg of lamb. 12f ounces breast of veal." 335. Digestibility of cheese. — Although it has been a staple food with many races for uncounted years, there is a widespread belief that cheese is suitable for use chiefly 368 THE BOOK OF CHEESE in small quantities as an accessory to the diet, and that in large quantities it is likely to produce physiological disturbances. The question of digestibility was made the subject of a special investigation by the United States Department of Agriculture.^ Calorimeter experiments^ were made to test the digestibility of several varieties of cheese and some of these varieties at various stages of ripening. All forms of cheese were found to be digested as completely as most of the usual forms of food. Ap- proximately 90 per cent of the nitrogenous portion (casein) was retained in the body. Unripe cheese in these experi- ments was apparently digested as completely as the ripened forms. These experiments make clear the possibility of making cheese a more prominent article in the regular dietary than is usual in America. They especially point to the desirability of the use of the skim and partially skim cheeses, which as cheap sources of protein when properly combined with other foods, may be made to replace meats as a less costly source of proteins. Cheese is then to be classed with meat and eggs, not with condiments. An ounce of Cheddar^ cheese roughly is equi\'alent to one egg, to a glass of milk, or to two ounces of meat. It is properly to be combined with bread, potatoes and other starchy foods, lacking in the fat in which the cheese is rich. These experiments included Roquefort, fresh-made and ripe Cheddar, Swiss, Camembert and Cottage cheese. 336. Cheese flavor. — " Cheese owes its flavor to the fatty acids and their compounds which it contains and to ammonia-like bodies formed during ripening from the 1 Doane, C. F., et ah. The digestibility of cheese, U. S. Dept. Agr. Bur. An. Ind. Circ. 166, pages 1-21, 1911. 2 Langworthy and Hunt, loc. cit. 3 U. S. Dept. Agr. Farmers' Bui. 487, page 38. CHEESE IN THE HOUSEHOLD 369 cleavage of the casein, to salt added to the curd, and in some varieties, like Roquefort, to bodies elaborated by molds which develop in the cheese. In the highly flavored sorts some of the fatty acids of a very marked odor are present in abundance, as are also the ammonia-like bodies. Indeed, in eating such cheese as Camembert a trace of ammonia flavor may often be plainly detected. " The cleavage of the nitrogenous material of the cheese and other changes are brought about chiefly by the action of enzymes originally present in cheese or by micro-or- ganisms and are to be regarded as fermentative and not as putrefactive changes. " The liking for highly flavored cheeses of strong odor is a matter of individual preference, but from the chemist's standpoint there is no reason for the statement often made that such cheeses have undergone putrefactive decomposition." 337. Relation to health. — In connection with the use of cheese as a food, its relation to the health of the con- sumer must be considered. The presence of the bacillus of tuberculosis in milk has led to careful study of its possible presence in cheese. When American Cheddar cheese was specially inoculated for this purpose, the living organism was recovered from it after about five months by Schroeder of the United States Department of Agriculture. This danger is much greater from cheeses, such as Cream and Neufchatel, which are eaten when com- paratively freshly made. The disease has been produced in guinea pigs from such cheese often enough to emphasize the desirability of developing methods of making every variety possible from thoroughly pasteurized milk. This would remove the danger of tuberculosis and with it eliminate the possibility of transmitting other diseases. 2b 370 THE BOOK OF CHEESE 338. Cheese poisoning ^ cases occasionally occur. These take two main forms : (1) an enteritis (caused by Bacillus enteriiidis) or some other member of that series which while painful and accompanied by purging is rarely fatal ; (2) acute toxaemias which, although rare, usually result in death. From the latter type a variety of Bacillus hotulinus, an organism usually associated with meat poisoning, was isolated by the New York State Depart- ment of Health. The occurrence of such cases is frequent enough to emphasize the desirability of using every pre- caution to reduce the number of bacteria that are allowed to enter milk when drawn and to prevent the development of those which actually gain access to it. When j)()ssible, pasteurization should be introduced. 339. Proper place in the diet. — It has already been noted that cheese is used " in general in two ways — in small quantities chiefly for its flavor and in large quan- tities for its nutritive value as well as for its flavor. Some \arieties of cheese are used chiefly for the first purpose, others chiefly for the second. Those which are used chiefly for their flavor, many of which are high priced, contribute little to the food value of the diet, because of the small quantity used at a time. They have an important part to play, however, in making the diet attractive and ])alatable. The intelligent housekeeper thinks of them not as necessities, but as lying within what has been called ' the region of choice.' Having first satisfied herself that her family is receiving sufficient nourishment, she then, according to her means and ideas of an attractive diet, chooses among these foods and others which are to be considered luxuries. ^ Levin, W., Cheese poisoning — a toxieogenic bacilhis iso- lated from cheese, Jour. Lab. Clin. Med. 2 (1917), page 761. CHEESE IN THE HOUSEHOLD 371 "Those cheeses, on the other hand, which are suitable to be eaten in larfi;e quantities and which are comparatively low priced are important not only from the point of view of flavor, but also from the point of view of their nutritive value." Among such cheeses are American Cheddar, Swiss, Brick, Limburger and the lower priced forms of Neufchatel. It is clear that in buying cheese, the housekeeper should know definitely the dietary purpose of the pur- chase, and then choose the variety of cheese best suited. To a very large degree the personal tastes of the family determine the kinds of cheese which will be tolerated when served uncooked. In some families, the strong flavors of Roquefort or Limburger are not acceptable. However, there is a range of choice in which much judg- ment can be used. Cheese to be served with mild-flavored foods should as a rule be also mild-flavored. P^or most sandwiches, for example, Cheddar or Swiss is usually very acceptable; Brick or partly ripe Limburger still hard enough to slice cuts into thin rectangular slices and is very attractive to many consumers because it has some- what more flavor without being too strong. With proper handling it is good policy to buy the cheapest of these forms for this ])urpose. The selection of dessert cheeses offers the widest range. If served with mild-flavored crackers, very many persons })refer Cream, Neufchatel or mild Cheddar ; a little stronger taste calls for club cheese, or Camembert. If tobacco smoke is present, Roquefort, Gorgonzola, Limburger and related types will satisfy many consumers better than mild cheeses. The inten- sity of flavor to be sought in the cheese should thus be adjusted to the food served with it. A person with an aversion to strong-smelling or strong-tasting cheese has 372 THE BOOK OF CHEESE been frequently known to approve over-ripe Camembert, or Limburger when served without label but spread upon a ginger cracker. For cooking purposes, some recipes prescribe cheese of special quality. In large markets, old Cheddar ripened carefully for two or three years is commonly purchasable for Welsh rabbit. (Ask for " rabbit " cheese.) An expert housekeeper familiar also with cheese ripening has demonstrated that almost any cheese, whether ripened to its best, part ripe or over-ripe, can be used in many cooking formulas without injuring the acceptability of the product to most consumers. In canning Camembert, it has been shown ^ that over-ripe cheese so strong as to be objectionable, when sterilized loses the objectionable flavor of the raw product. No cheese should be wasted ; any not used when served the first time should be served at a closely following meal or used in cooking. No matter what the variety, it will add to the food value and palatability of some one of the common dishes served within forty-eight hours. 340. Care of cheese.'^ — " One of the best ways of keeping cheese which has been cut is to wrap it in a slightly damp cloth and then in paper, and to keep it in a cool place. To dampen the cloth, sprinkle it and then wring it. It should seem hardly damp to the touch. Paraffin paper may be used in place of the cloth. When cheese is put in a covered dish, the air should never be wholly excluded, for if this is done, it molds more readily. "In some markets it is possible to buy small whole cheeses. These may be satisfactorily kept by cutting ^ Thorn, C, Camembert cheese problems in the United States, U. S. Dept. Agr. Bur. An. Ind. Bui. 115. ^Langworthy and Hunt, loc. cit. CHEESE IN THE HOUSEHOLD 373 a slice from the top, to serve as a cover, and removing the cheese as needed with a knife, a strong spoon, or a cheese scoop. It is ]M)Ssihle to \my at the hardware stores knobs which inserted in the layer cut from the top make it easy to handle. The cheese with the cover on should be kept wrapped in a cloth." ' 341. Food value and price. — There is little relation between the price and food value of standard varieties of cheese. The higher-priced varieties claim and hold their place because they possess particular flavors. These may or may not accompany high comparative food values. Even among low-j)ricc(l varieties discrimination into grades is largely })ascd on flavor. Of the low-priced cheeses, those made from skimmed-milk commonly command the lowest prices. As noted above, a choice may be based either on purpose or on price. If the purpose is fixed, the price should not change the selection. If, however, a particular cpiality of cheese is purchasable at a low price, some satisfactory form of utilizing it is clearly available to the housekeeper. Some standard recipes arc given in the following i)aragraphs. 342. Methods and recipes for using cheese. — (1) As a meat substitute. Meat is wholesome and relished by most persons, yet it is not essential to a well-balanced meal and there are many housekeepers who for one reason or another are interested in lessening the amount of meat or to substitute other foods. The problem with the average family is undoubtedly more often the occasional substitution of other palatable dishes for the sake of variety, for reasons of economy, or for some other reason than the general replacement of meat dishes by other things. Foods which are to be served in place of meat should be rich in protein and fat and should also be savory. 374 THE BOOK OF CHEESE Cheese naturally suggests itself as a substitute for meat, since it is rich in the same kinds of nutrients that meat supplies, is a staple food with which every one is familiar and is one which can be used in a great variety of ways. In substituting cheese for meat, especial pains should be taken to serve dishes which are relished by the members of the family. A number of recipes^ for dishes which contain cheese are given below. They are preceded by several recipes for cheese sauces which, as will appear, are called for in the preparation of some of the more substantial dishes. In the first list of recipes, cheese means Cheddar. Cheese Sauce No. i 1 cupful of milk. , 1 ounce of cheese (| cupful of 2 tablespoonfuls of flour. grated cheese). Salt and pepper. Thicken the milk with the flour and just before serving add the cheese, stirring until it is melted. This sauce is suitable to use in preparing creamed eggs, or to pour over toast, making a dish corresponding to ordinary milk toast, except for the presence of cheese. It may be seasoned with a little curry powder and poured over hard-boiled eggs. Cheese Sauce No. 2 Same as cheese sauce No. 1, except that the cheese is in- creased from 1 to 2 ounces. This sauce is suitable for using with macaroni or rice, or for baking with crackers soaked in milk. Cheese Sauce No. 3 Same as cheese sauce No. 1, except that two cupfuls of grated cheese or 8 ounces are used. This may be used upon toast as a substitute for Welsh rabbit. ^ Langworthy and Hiint, loc. cit. CHEESE IN THE HOUSEHOLD 375 Cheese Sauce No. 4 Same as cheese sauce No. 2, save that 2 tablespoonfuls of melted butter are mixed with the flour before the latter is put into the milk. This sauce is therefore very rich in fat and has only a mild flavor of cheese. Among the recipes for dishes which may be used like meat, the following give products which, eaten in usual quantities, will provide much the same kind and amount of nutritive material as the ordinary servings of meat dishes used at dinner. In several cases there is a resemblance in appearance and flavor to common meat dishes, which would doubtless be a point in their favor with many families. (2) For general cooking purposes: Cheese Fondue No. i I5 cupfuls of soft, stale bread crumbs. 4 eggs. 6 ounces of cheese (I5 cupfuls of grated 1 cupful of hot water. cheese or 1| cupfuls of cheese grated 5 teaspoonful of salt. fine or cut into small pieces). Mix the water, bread crumbs, salt and cheese ; add the yolks thoroughly beaten ; into this mixture cut and fold the whites of eggs beaten until stiff. Pour into a buttered baking dish and cook 30 minutes in a moderate oven. Serve at once. The food value of this dish, made with the above quantities, is almost exactly the same as that of a pound of beef of average composition and a pound of potatoes combined. It contains about 80 grams of proteids and has a fuel value of about 1300 calories. Cheese Fondue No. 2 1| cupfuls of hot milk. 5 of a pound of cheese (I5 cup- I5 cupfuls of soft, stale bread fuls of grated cheese or 1 crumbs. cupful of cheese cut into 1 tablespoonful of butter. small pieces). 4 eggs. I teaspoonful of salt. 376 THE BOOK OF CHEESE Prepare as in previous recipe. The protein value of this dish is equal to that of I5 pounds of potato and beef, the fuel value, however, being much in excess of these. In making either of these fondues, rice or other cereals may be substituted for bread crumbs. One-fourth cupful of rice measured before cooking, or one cupful of cooked rice or other cereals, should be used. Corn and Cheese Souffle 1 tablespoonful of butter. 1 cupful of chopped corn. 1 tablespoonful of chopped green 1 cupful of grated cheese, pepper. 3 eggs. 1 cupful of flour. I teaspoonful of salt. 2 cupfuls of milk. Melt the butter and cook the pepper thoroughly in it. Make a sauce out of the flour, milk and cheese ; add the corn, cheese, yolks and seasoning ; cut and fold in the whites beaten stiffly ; turn into a buttered baking dish and bake in a moderate oven 30 minutes. Made with skimmed-milk and without butter, this dish has a food value slightly in e.xcess of a pound of beef and a pound of potatoes. Cheese Souffle 2 tablespoonfuls of butter. A speck of cayenne. 3 tablespoonfuls of flour. \ cupful of grated cheese. § cupful of milk (scalded). 3 eggs. 5 teaspoonful of salt Melt the butter; add the flour and, when well mixed, add gradually the scalded milk. Then add salt, cayenne and cheese. Remove from the fire and add the yolks of the eggs, beaten until lemon colored. Cool the mixture and fold into it the whites of the eggs, beaten until stiff. Pour into a buttered leaking dish and cook 20 mmutes in a slow oven. Serve at once. The proteid of this recipe is equal to that of half a pound of beef ; the fuel value is equal to that of three-fourths of a pound. CHEESE IN THE HOUSEHOLD 377 Welsh Rabbit 1 tablespoonful of butter. 2 pound of cheese, cut into small 1 teaspoonful of corn-starch. pieces. ^ cupful of milk. j teaspoonful each of salt and mustard. A speck of cayenne pepper. Cook the corn-starch in the butter ; then add the milk gradu- ally and cook two minutes ; add the cheese and stir until it is melted. Season and serve on crackers or bread toasted on one side, the rabbit being poured over tlie untoasted side. Food value is that of about three-fourths of a pound of beef. Macaroni and Cheese No. i 1 cupful of macaroni, broken into small 2 tablespoonfuls of flour. pieces. j to 2 pound of cheese. 2 quarts of boiling salted water. 2 teaspoonful of salt. 1 cupful of milk. Speck of cayenne pepper. Cook the macaroni in the boiling salted water, drain in a strainer, and pour cold water over it to prevent the pieces from adhering to each other. Make a sauce out of the flour, milk, and cheese. Put the sauce and macaroni in alternate layers in a buttered leaking dish, cover with buttered crumbs, and heat in oven until crumbs are brown. Macaroni and Cheese No. 2 A good way to prepare macaroni and cheese is to make a rich cheese sauce and heat the macaroni in it. The mi.xture is usually covered with buttered crumbs and browned in the oven. The advantage of this way of preparing the dish, however, is that it is unnecessary to have a hot oven, as the sauce and macaroni may be reheated on the top of the stove. Baked Rice and Cheese No. i 1 cupful of uncooked rice and 2 tablespoonfuls of flour. 4 cupfuls of milk ; | pound of cheese. or, I teaspoonful of salt. 3 cupfuls of cooked rice and 1 cupful of milk. 378 THE BOOK OF CHEESE If uncooked rice is used, it should be cooked in 3 cupfulsof milk. Make a sauce with one cupful of milk, add the flour, cheese and salt. Into a buttered baking dish put alternate layers of the cooked rice and the sauce. Cover with buttered crumbs and bake until the crumbs are brown. The proteids in this dish, made with rice cooked in milk, are equal to those of nearly If pounds of average beef. If skimmed-milk is used, the fuel value is equal to nearly 3^ pounds of beef. Whole milk raises the fuel value still higher. Fried Bread with Cheese No. i 6 slices of bread. | teaspoonful of salt. 1 cupful of milk. 5 teaspoonful of potassium bi- 2 ounces of cheese, or | cupful carbonate. of grated cheese. Butter or other fat for frying. Scald the milk with the potassium bicarbonate ; add the grated cheese, and stir until it dissolves. Dip the bread in this mixture and fry it in the butter. The potassium bicarbonate helps to keep the cheese in solution. It is desirable, however, to keep the milk hot while the bread is being dipped. Plain Cheese Salad Cut Edam or ordinary American cheese into thin pieces, scatter them over lettuce leaves and serve with French dressing. Olive and Pimiento Sandwich or Salad Cheese Mash any of the soft cream cheeses and add chopped olives and pimientos in equal parts. This mixture requires much salt to make it palatable to most palates, the amount depending chiefly on the quantity of pimiento used. The mixture may be spread between thin slices of bread or it may be made into a roll or molded, cut into slices and served on lettuce leaves with French dressing. Cheese and Tomato Salad Stuff cold tomatoes with cream cheese and serve on lettuce leaves with French dressing. CHEESE IN THE HOUSEHOLD 379 Cheese and Pimiento Salad Stuff canned pimientos with cream cheese, cut into slices and serve one or two slices to each person on lettuce leaves with French dressing. (3) Ways to use cottage cheese. Cottage cheese alone is an appetizing and nutritious dish. It may also be served with sweet or sour cream, and some persons add a little sugar, or chives, chopped onion or caraway seed. The following recipes ^ illustrate a number of ways in which cottage cheese may be served : Cottage Cheese with Preserves and Jellies Pour over cottage cheese any fruit preserves, such as straw- berries, figs or cherries. Serve with bread or crackers. If pre- ferred, cottage cheese balls may be served separately and eaten with the preserves. A very attractive dish may be made by dropping a bit of jelly into a nest of the cottage cheese. Cottage Cheese Salad Mix thoroughly one pound of cheese, one and one-half table- spoonfuls of cream, one tablespoonful of chopped parsley and salt to taste. First, fill a rectangular tin mold with cold water to chill and wet the surface ; line the bottom with waxed paper, then pack in three layers of the cheese, putting two or three parallel strips of pimiento, fresh or canned, between the layers. Cover with waxed paper and set in a cool place until ready to serve ; then run a knife around the sides and invert the mold. Cut in slices and serve on lettuce leaves with French dressing and wafers or thin bread-and-butter sandwiches. Minced olives may be used instead of the parsley, and chopped nuts also may be added. Cottage Cheese Rolls (To be used like meat rolls.) A large variety of rolls, suitable for serving as the main dish at dinner, may be made by combining legumes (beans of various kinds, eowpeas, lentils or peas) with cottage cheese, and adding lU. S. Dept. of Agr. Bur. An. Ind. A. I. 18. 380 77//'; HOOK OF CHEESE l)r(>a(l crumhs lo make (lie tiiixliirc lliicU (Mioiitrli lo i'orTii into a roll. Ii(uiiis are usually ruaslicd, hut, peas or small Jjima boatis may he eomhiiied wiiole with hread crumhs and coUaKo cheese, and (Wiouf^h of (he licjuor in whielr the vefjetahles have boon cooked siiould he added to jjet the rifi;ht (!onsisten(\y ; or, instead of beans or peas, ehopixHl spinach, beet tops or head lettuce may be added. Boston Roast 1 pound cati of kidney beans, or e(iuivalent quantity of cooked beans. J pound of cottage cheese. Broad crumbs. Salt. Mash the beans or put Ihem throufifh a meat grindcir. Add the cheese and bn^ad crundts enouti:h to mak<» the mixture suffi- oiently stilT lo be formed into a roll. Make in a moderate oven, bastirif,' oc(iasionally willi butter or other fat, a,nd water. Serve with tomato sa-iice. This dish may Ix- (lavored with chopped onions (looked until tender in l)utter or other fat and a V(!ry little water. Pimiento and Cottage Cheese Roast 2 cupfuls of cooked Lima beans, .'i canned pi mien tos chopped. } pound of cottafjfe cheese. iiread