HaU (QolUge of JVgticultuw 
 
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 3tiiam. «. 1. 
 
Cornell University Library 
 SF 251.W77 1907 
 
 Milk and its products; a treatise upon th 
 
 3 1924 003 041 419 
 
B Cornell University 
 9 Library 
 
 The original of tliis bool< is in 
 tine Cornell University Library. 
 
 There are no known copyright restrictions in 
 the United States on the use of the text. 
 
 http://www.archive.org/details/cu31924003041419 
 
MILK AND ITS PRODUCTS 
 
jrt^^^ 
 
MILK AND ITS PRODUCTS 
 
 A TREATISE UPON THE NATURE AND QUALITIES OF 
 
 DAIRY MILK AND THE MANUFACTURE 
 
 OP BUTTER AND CHEESE 
 
 BY 
 
 HENRY H. WING 
 
 Professor of Dairy Husbandry in the 
 Cornell University 
 
 ELEVENTH EDITION 
 
 THE MACMILLAN COMPANY 
 
 LONDON: MACMILLAN & CO., Ltd. 
 
 1907 
 
 All rights reserved 
 
Ta TOs Fatter 
 
 AS A SLIGHT TRIBUTE TO THE CAREFUL TRAINING AND 
 
 WISE AND SYMPATHETIC COUNSEL THAT 
 
 SERVED TO INSTIL IN THREE FARM BOYS A LOVE FOR ALL 
 
 THAT PERTAINS TO FARM LIFE 
 
 TlTts littlB mark is affstAxanutzlg xmcvibzA 
 
 (v) 
 
PREFACE. 
 
 The revolution in dairy practice brought about 
 by the inti'oduction of the centrifugal cream sepa- 
 rator and the Babcock test for fat and by a more 
 definite knowledge regarding the various fermenta- 
 tions that so greatly influence milk and the manu- 
 facture of its products, has seemed to demand the 
 publication of a small handbook that shall give 
 to the dairyman, and particularly to the dairy 
 student, in simple, concise form, the principles un- 
 derlying modern dairy practice. In attempting to 
 meet this demand, I have had largely in view the 
 needs of my own students, while still keeping in 
 mind the general dairy reader. 
 
 In the collation of the information, where so 
 many points are still unsettled, it is of course dif- 
 ficult in all cases to distinguish fact from conjec- 
 ture. The aim has been at all times to give 
 the present state of knowledge as supported by 
 the weight of evidence and the opinions of those 
 whose authority is highest. In how far this has 
 been successful time alone can tell. It would be 
 
 (yii) 
 
viii Preface. 
 
 too much to hope that every conclusion will stand 
 the test of further investigation and experience. 
 
 Dairy practice in the United States owes much 
 to the investigations of the Agricultural Experiment 
 Stations. Of the results of their labor free use 
 has been made in various ways, and in many cases 
 without specific mention at the particular place. 
 Without wishing to make distinctions, particular 
 acknowledgment is here rendered to the reports 
 and bulletins of the Stations in Maine, New Hamp- 
 shire, Vermont, Connecticut (Storrs), Canada, New 
 York (State), New York (Cornell), New Jersey, 
 Pennsylvania, Illinois, Iowa, Wisconsin and Minne- 
 sota. For those who wish to make more extended 
 investigations, a bibliography is added in the Ap- 
 pendix, giving references to many bulletins. 
 
 Thanks are due to D. H. Burrell & Co., the 
 Vermont Farm jiachine Co., the DeLaval Separator 
 Co., the Star Milk Cooler Co., the Champion Milk 
 Cooler Co., J. F. Hodgkin, and F. B. Fargo & Co., 
 for the use of electrotypes. 
 
 Acknowledgment is also due my colleagues, 
 Messrs. Cavanaugh, Durand, Hall and VanWagenen, 
 for valuable assistance, and to Professor L. H. 
 Bailey for much friendly counsel and many useful 
 suggestions. 
 
 HENRY H. WING. 
 
 Cornell University Dairy, 
 January 1897. 
 
CONTENTS. 
 
 CHAPTEE I. 
 
 Secretion of Milk. 
 
 Alilk defined — Mammary glands — Udder — Internal structure of 
 udder and teats — Ultimate follicle — Secretion of milk — In- 
 centives to secretion — Amount and duration of flow — Effect 
 of succeeding pregnancy — Incomplete removal of milk — Reg- 
 ularity and frequency of milking — Control of animal over 
 secretion. 
 
 Pages 1-15 
 
 CHAPTEE II. 
 
 Composition of Milk. 
 
 Milk constituents — Colostrum — Specific gravity — The fats — The 
 volatile fats — The non -volatile fats — The albuminoids — The 
 sugar — The ash — Other constituents — Variations in quality 
 of milk. 
 
 Pages 16-34 
 
 CHAPTEE III. 
 
 The Testing op Milk. 
 
 Gravimetric analysis — History of milk tests -^ Cream gauges — 
 Specific gravity — Lactometers — Churn tests — Laotobutyro- 
 meter — Pioscope — Laotoscope — Soxhlet's method — Lacto- 
 erite — Fjord's control apparatus — Milk tests in the United 
 States — Short's method — Method of Failyer and Willard — 
 
X Contents. 
 
 Parsons' method— Iowa Station test — Cochran's method — 
 Babcoek test — Beimling test — Gerber's method — But.yrom- 
 eter — Details of Babcoek test — The centrifugal machine — 
 The glassware — Sampling the milk — Composite sampling — 
 Making the test — The acid — Whirling — Beading- Cleaning 
 
 the glassware. 
 
 Pages 35-65 
 
 CHAPTER IV. 
 
 The Ferments and Fermentations of Milk and 
 Their Control. 
 
 Tendency to undergo change — Germs of fermentation — Bacteria — 
 Presence of bacteria in milk — Kinds of bacteria in milk — 
 Fermentations of milk — Relation of milk bacteria to the 
 human system — Lactic fermentations — Fermentations affect- 
 ing the albuminoids — Butyric fermentations — Control of fer- 
 mentations — Prevention of infection — Holding at low tem- 
 peratures — Destruction of germs in milk — Pasteurization — 
 Selection of milk for pasteurization. 
 
 Pages 66-82 
 
 CHAPTER V. 
 Market Milk. 
 
 Milk for consumption — Cleanliness — Treatment after drawing — 
 Aeration — Delivery — Bad flavors in milk — Quality of milk 
 for consumption — Control of milk supply — -Cream for con- 
 sumption — Pasteurized cream — Quality of cream. 
 
 Pages 83-96 
 
 CHAPTER VI. 
 
 Separation op Cream. 
 
 Gravity creaming — Shallow-pan creaming — Deep setting system — 
 Centrifugal separation — Conditions affecting completeness of 
 separation — Conditions affecting the relative amount of 
 skimmed milk and cream — Contrivances in the bowl to 
 
Contents. xi 
 
 increase the efficiency of separation — Mechanical conditions 
 affecting separation — Efficiency of separation in centrif- 
 ugal machines — Desirable and undesirable features of a sep- 
 arator. 
 
 Pages 97-] 26 
 
 CHAPTER VII. 
 
 The Ripening op Cream. 
 
 Means of producing lactic acid — Temperature of ripening — 
 Amount of acid necessary — Acid tests — Determination of 
 lactic acid in milk and cream— Further effects of ripening — 
 Churning cream of different degrees of ripeness — Bad effects 
 of over -ripening. 
 
 Pages 1'27-139 
 
 CHAPTER VIII. 
 
 Chubninq. 
 
 Viscosity of the milk— Ripeness of cream— Temperature— Nature 
 of agitation— Quality of the globules of fat— End of churn- 
 ing — Difficult churning. 
 
 Pages 140-149 
 
 CHAPTER IX. 
 
 Finishing and Marketing Butter. 
 
 Washing the butter— Working— Salting — Brine salting— Pack- 
 ing and marketing— Composition and quality of buttei. 
 
 Pages 150-162 
 
 CHAPTER X. 
 
 Milk for Cheese Making. 
 
 Theory of cheese making— Quality of milk for cheese making- 
 Loss of fat— Cooling— Aeration— Ripening— Rennet tests- 
 Degree of ripeness necessary— Starters — Rennet — Removal 
 
 of whey. 
 
 Pages 163-180 
 
xii Contents. 
 
 CHAPTEE XI. 
 
 Cheddar Cheese Making. 
 Setting — Cutting — Heating — Cheddaring — Grinding— Salting — 
 Curing — DifBouIties likely to occur in cheddar cheese mak- 
 ing — Qualities of Cheese. 
 
 Pages 181-198 
 
 CHAPTER XII. 
 Varieties op Cheese. 
 Home-trade or stirred-curd cheese — Sage cheese — Young Amer- 
 ica — Picnics — Pineapple — Truckle — American Neufchatel — 
 Philadelphia cream cheese — Limburger — Imitation Swiss — 
 Prepared cheese — English cheese — Stilton — Cheshire — 
 Lancashire — Derbyshire — Leicestershire — Wensleydale — 
 Gorgonzola — Emraenthaler or Swiss — Edam — Gouda — 
 Koquefort — Brie — Camembert — D'Isigny — Pont L'Eveque — 
 Port du Saint — Parmesan. 
 
 Pages 199-228 
 
 CHAPTER XIII. 
 By-Products op the Dairy. 
 Skimmed milk, buttermilk and whey — Dried Casein — Milk 
 sugar — Dutch cheese — Whey cheese — Cheese food — Kou- 
 miss — Kephir — Wheyn. 
 
 Pages 229-235 
 
 CHAPTER XIV. 
 Butter and Cheese Factories. 
 Location of creameries ^ Arrangement of building — Construc- 
 tion — Cheese factories — Combined butter and cheese fac- 
 tories — Farm dairy buildings. 
 
 Pages 236-247 
 
 CHAPTER XV. 
 Statistics and Economics op the Dairy Industry. 
 Increase in dairy production — Development of the factory sys- 
 tem — Condensed milk — Dairy legislation — Dairy markets. 
 
 Pages 248-258 
 
Contents. xiii 
 
 APPENDIX. 
 
 A. Useful rules and tests. 
 
 Pages 259-26G 
 
 B. Metric system of weights and measures. 
 
 Pages 267-263 
 
 C. Legal standards for milk in the various states — The oleomar- 
 
 garine law — The filled-oheese law — The New York state 
 dairy law. 
 
 Pages 269-288 
 
 D. References to Agricultural Experiment Station reports and 
 
 bulletins. 
 
 Pages 289-297 
 
 INDEX. 
 
 Pages 299-311 
 
Uilders of t;nod ami poor types 
 From Bulletin No. 62, Piuxluf I'niv. Arv. Exp. .Sta.. l.y pfrmissiou. 
 
 See pat;^ J. 
 
MILK AND ITS PRODUCTS. 
 
 CHAPTER I. 
 THE SECRETION OF MILK. 
 
 The females of all animals that suckle their 
 young (class Mammalia) secrete for this purpose a 
 special fluid which is known as milk. It is an 
 opaque yellowish white fluid, with a slight alkaline 
 reaction and a faintly sweetish taste. It consists 
 of an emulsion of fats in a watery solution of 
 alkaline salts, casein and sugar. It is secreted in 
 two special glands situated without the body cavity 
 on either side of the median line, and known as 
 the mammary glands or mammae. 
 
 Mammary glands. — While, strictly speaking, there 
 are but two glands, each gland may be divided 
 into two or more lobes, each having a separate open- 
 ing ; thus, while there are ordinarily but two simple 
 glands in the ewe, mare and goat, in the cow there 
 are four or six, in the cat and bitch six to ten, and 
 in the sow ten to fourteen. In animals having 
 multiple glands, the mammae occupy nearly the whole 
 of the lower part of the chest and abdomen. In 
 other animals the glands are confined either to the 
 chest or abdomen. In many animals each gland 
 
2 Milk and Its Products. 
 
 or lobe is furnished with a single opening connect- 
 ing with a single duct, in others several ducts 
 open independently upon the surface of a single 
 nipple or teat. The mammary gland is a true 
 organ of secretion in the sense that its product (milk) 
 contains substances not ' before existing in the blood, 
 that are formed during the process of secretion in the 
 gland itself. In the cow the mammary glands are lo- 
 cated on the posterior portion of the abdomen be- 
 tween the hind legs, and each gland is made up of 
 two lobes or quarters, each having a single outlet 
 furnished with a single duct, though there are often 
 one and sometimes two rudimentary ducts upon the 
 rear quarters, and which are occasionally developed to 
 such an extent that milk may be drawn from them 
 in small quantities. The whole organ is spoken of as 
 the udder, and the ducts as teats. While the mam- 
 mary gland is essentially a female organ, it is present 
 in a rudimentary condition in the males of all mam- 
 mals, and in exceptional cases in man and in the lower 
 animals the organs of males have developed to such a 
 degree as to secrete milk. 
 
 The cow's udder. — The udder is enclosed in a fold 
 of skin, which is here thinner and softer than upon 
 other parts of the body, and is supported by a band 
 of fibrous tissue that springs from the median line of 
 the body and extends through the whole substance of 
 the gland. It varies very much in size and shape 
 in different animals and in the same animal at dif- 
 ferent times. Its size is not always an indication 
 of the secreting powers of an animal, since the num- 
 
structure of the Udder. 3 
 
 ber of true secreting follicles does not necessarily bear 
 any relation to the apparent size. The udder in a 
 good cow should be large and well developed ; it 
 should occupy the whole space between the hind 
 legs, extending well up between the thighs and 
 well forward upon the belly. It should be held 
 firmly against the wall of the abdomen. It should 
 be level or nearly so on the bottom, and the four 
 quarters should be as nearly as possible equally 
 developed and each furnished with a cylindrical per- 
 pendicular teat of moderate length. "Die whole 
 organ should diminish rapidly in size as the milk 
 is withdrawn. The hair upon the udder should be 
 fairly abundant, fine and soft, and abundantly sup- 
 plied with a brownish dandrufif. 
 
 The substance of the udder is composed of the 
 fibrous band, already mentioned, connective tissue, 
 fatty tissue, milk ducts or canals, true secreting 
 cells (acini, ultimate follicles, alveoli), veins, arte- 
 ries, nerves and lymphatics, the whole making i&|^ 
 reddish gray mass of spongy texture. ^^ , 
 
 The udder varies very much, in different indi- 
 viduals, in size and shape as well as in internal 
 structure and secreting capacity. In some animals 
 the amount of connective and fatty tissue is much 
 larger than in others. Such udders are said to be 
 "fleshy," and while usually of large size and good 
 shape, are deficient in true secreting capacity. They 
 are firm to the touch, particularly when empty, ^nd 
 do not markedly diminish in size when the milk 
 is withdrawn. It is generally supposed that such 
 
4 Milk and Its Products. 
 
 udders are more subject to inflammations and in- 
 flammatory diseases than those with less fatty tissue, 
 in many cows the fibrous net -work that supports 
 the udder is held firmly up to the under side of the 
 abdomen. If, in connection with this, the udder has 
 comparatively little connective and fatty tissue, the 
 animal will have an udder apparently small, but with 
 large capacity for secretion. In old cows, particu- 
 larly those that have been large milkers, the fibrous 
 bands often become largely relaxed, so that the 
 udder falls nearly to the ground, and appears to be 
 of enormous size. 
 
 Internal structure of the udder and teats. — The 
 teat is simply a canal surrounded by muscular walls 
 and closed at the extremity by an involuntary 
 sphincter muscle, which varies much in rigidity in 
 different animals ; often it is so lax that the pressure 
 of a small amount of milk in the canal is sufficient 
 to open it and the animal leaks her milk. In other 
 animals it requires a strong effort of the hand to 
 draw the milk. When desirable, the rigidity may be 
 overcome by keeping a smooth wooden plug of suf- 
 ficient size to moderately dilate the opening in the 
 end of the teat till the muscle relaxes sufficiently 
 to permit easy drawing of the milk, or the muscle 
 may be partially divided with the knife in the 
 hands of a skilful operator. At the top of the 
 teat, or bottom of the udder, there is a small 
 cavity known as the milk cistern, serving to hold 
 the milk after its secretion until it is drawn. 
 It is of varying capacity, up to half a pint, 
 
Arrangement of Milk Ducts. 5 
 
 and is partially separated from the canal of the 
 teat by a more or less well - marked constriction 
 in the muscular walls of the upper part of the 
 teat. From the milk cisterns a system of canals 
 or so-called milk duets extends to all portions of 
 the udder. These ducts are larger near their open- 
 ing into the milk cistern, and diminish in size 
 as they rise through the udder. They branch and 
 anastomose freely in all directions, and finally end 
 in a group of small sac -like bodies, the ultimate 
 follicles. The system of milk ducts arising from 
 each teat is practically distinct, though there is 
 more or less communication between the smaller 
 ducts in the tipper portions of the two quarters 
 on the same side of the animal. This renders 
 it possible to draw a part of the milk secreted 
 in the hind quarter from the forward teat on 
 the same side, and vice versa. There is no com- 
 munication between the ducts on opposite sides 
 ■of the animal. At the junctions of the larger 
 duets there are greater or smaller enlargements, 
 forming small cavities or milk reservoirs, which 
 serve the same purpose as the reservoirs at 
 the top of the teat. The branching points of 
 all the ducts, large and small, are guarded by 
 sphincter muscles. These muscles are connected 
 with the abdominal muscles of the animal, and she 
 is able to more or less completely close them at 
 will, and so "hold up" her milk. It requires a 
 strong effort on the part of the animal to com- 
 pletely close the larger ducts in the lower part of 
 
6 Milk and Its Products. 
 
 the udder ; a comparatively slight effort is all that is 
 necessary to close the smaller vessels. Animals vary 
 greatly both in the control they possess over these 
 muscles and in their disposition to use it. Very few 
 can completely close the larger ducts, and very many 
 rarelj' exercise whatever power they do possess. Sud- 
 den fright, the presence of strange persons or animals 
 in the stable, any irregularity in the time or manner 
 of feeding or milking, and slight feverish conditions, 
 particularly sexual heat, are the most common pro- 
 vocatives to holding up milk. There arfe very many 
 cows that contract the habit of holding up the milk 
 upon the slightest provocation, and if the habit is 
 once formed it is almost impossible to cure it, and 
 the result is that the usefulness of the animal as 
 a milk producer is largely destroyed, for the reten- 
 tion of the milk in the udder interferes greatly 
 with the activity of secretion, and in a short time 
 permanently lessens it. 
 
 The ultimate follicles. — The milk ducts, after 
 branching and anastomosing in all directions, finally 
 end in a group of small sac -like bodies known as 
 acini, or ultimate follicles. It is in these small 
 bodies that the secretion of the milk takes place. 
 They are about l-30th of an inch in diameter, and 
 are found in groups of three to five, with a com- 
 mon outlet at the end of each branching duet. 
 In form and appearance they present marked 
 changes according to the condition of the animal. 
 During active lactation they are found in their 
 highest development. When lactation ceases, the 
 
Secretion of Milk. 7 
 
 smaller ducts become much retracted, and the 
 follicles shrink in size and finally become rudimen- 
 tary, or even entirely disappear, until under the 
 stimulus of a succeeding pregnancy, the whole 
 gland renews its activity, and the ducts and fol- 
 licles regain their former size and appearance. 
 New duets and follicles may also be formed up to 
 about the fifth or sixth year, and the power of 
 the animal to secrete milk be thereby increased. 
 Surrounding the follicles, and intimately attached 
 to them, are' capillary blood vessels, both veins and 
 arteries, and through the cells of the membranes 
 making up the walls of all these vessels the fluids 
 of the blood freely pass into the cavity of the 
 follicles by means of osmosis, or transudation. 
 The cavity of the follicle is lined, with epithelial 
 cells, that during lactation are filled with proto- 
 plasm, and are capable of rapid multiplication, 
 growth, and degeneration, at the same time that 
 the cell contents are undergoing rapid and exten- 
 sive changes. 
 
 The secretion of milk. — The milk is formed from 
 the blood, partly by the transudation of the blood 
 serum directly into the cavity of the milk follicle, 
 and partly by a transformation of the contents of 
 the epithelial cells lining the cavity of the follicle, 
 which at this time are especially active. The 
 water passes directly from the ■ capillaries into the 
 milk follicles and ducts, carrying with it the min- 
 eral constituents in solution and a part of the al- 
 bumin of the blood serum; but by far the larger 
 
8 .¥///,■ <iu(l lis rroihiffs. 
 
 part of the albumin is in soiiii' way chaiiged dur- 
 ing its passage from the capillaries, and appears in 
 the cavity of the follicle as the casein of the milk. 
 
 Fig. 1. Section tlirougli alveoli of the mamiuiiry gland of the dog in first and 
 second stages of secretion. Fi'om Meade Smith, after Heidenliain. 
 
 When milk is being secreted, the lining cells of 
 the follicle are in a state of constant activity. 
 New cells are constantly being formed by budding 
 or fission (the cell elongates, a partition forms 
 across it, and the two halves so divided enlarge to 
 the size of the mother cell, and there are two cells 
 where but one existed before), and older cells are 
 as constantly breaking down. While this is going 
 on, the cell contents, consisting mainly of protoplasm, 
 become changed into a globnle of fat, and the 
 globules so formed are either extruded through the 
 cell wall into the cavity of the follicle, or set free 
 by the breaking down and reabsorption of the cell 
 wall. In all probability both processes take place. 
 Small portions of the fat may also be carried over 
 directly from the l:>lood and appear in the milk 
 without change. The milk sugar is probablj- formed 
 
Incentives to Secretion. 9 
 
 through a chemical change in the contents of these 
 lining cells, since but minute quantities of sugar 
 are found in the blood. 
 
 Incentives to secretion. — Maternity is the prime 
 incentive to the secretion of milk. While there is 
 a distinct increase in the development of the mammae 
 upon attaining puberty, it is not until pregnancy is 
 well advanced that the organ attains anywhere near 
 its full development, or that there is any activity 
 in the true secreting cells. In the virgin animal, 
 and up to within a sliort time of parturition, the 
 cavities and ducts of the udder contain a watery 
 saline fluid, but true milk does not appear until a 
 short time before, and in some cases not until after, 
 parturition. The immediate stimulus to the produc- 
 tion of milk is the turning of the blood that went 
 to nourish the foetus from the arteries of the uterus 
 to the arteries of the udder. The pressure of blood 
 in the vessels of the udder stimulates the secreting 
 cells to great activity, and the cells, hitherto dor- 
 mant, begin to multiply rapidly. When this activity 
 is first set up, the various processes of secretion are 
 more or less incomplete, so that the milk first se- 
 creted is very different in character from that se- 
 creted afterwards, and is known as colostrum. The 
 colostrum contains in the first place considerably 
 less water than normal milk; in the second place, 
 the transformation of albumin into casein is only 
 partial, so that colostrum contains large amounts of 
 albumin; and finally, when secretion of mOk begins, 
 the cells of the follicle multiply more rapidly than 
 
10 Milk and Its Products. 
 
 they can be reabsorbed, and portions of partially 
 broken down cells break . away from the walls of 
 the follicle and appear in the colostrum. Gradually 
 the colostrum takes on the character of normal 
 milk, and in the course of four or five days the 
 change is complete. Other characteristics of colos- 
 trum are discussed in detail in the next chapter. 
 
 While maternity is the prime cause of secretion, 
 it is not the only means of stimulation to the ac-. 
 tivity of the udder, nor is it a necessary prerequisite 
 to the secretion of milk. The regular removal 
 of the saline fluid in the gland of the virgin 
 animal, or even the stimulation of the organ by the 
 friction of the hand or the suckling of a calf, may 
 be sufficient to cause the secretion of milk of nor- 
 mal character in considerable quantities. In the 
 same way and under the same exciting causes, other 
 glands of the body, notably the lymphatics in the 
 arm pits and the rudimentary mammse of males, 
 have been known to secrete a fluid resembling milk 
 in all essential characteristics. 
 
 Amount and duration of flow. — With wild ani- 
 mals in a state of nature, the milk is. secreted only 
 in amount sufficient for the needs of the young 
 animal, and only until the young is sufficiently de- 
 veloped to secure its food independently of the 
 mother. Under the influence of domestication the 
 cow has been brought to increase her flow of milk 
 many fold, and the time during which it is se- 
 creted has been lengthened until it is almost, and 
 indeed is, in some cases quite continuous. A dis- 
 
Dependence upon Circulation of Blood. 11 
 
 cussion of the agencies by means of which ' this 
 most important result has been brought about 
 would open up the whole question of the selection, 
 breeding and training of cows, as well as every- 
 thing pertaining to the science of foods and feed- 
 ing, which is not here possible. There are, how- 
 ever, some physiological conditions affecting the 
 secretion of milk that may be mentioned. 
 
 Milk is secreted from the blood. The amount 
 of milk secreted will, therefore, depend upon the 
 amount of blood passing through the udder, and 
 this, in turn, will depend upon the number and 
 size of the blood vessels, not only in the udder it- 
 self, but leading to it and away from it, the vigor 
 of the circulation, the supply of food to the ani- 
 mal, and her capacity to eat, digest and assimilate 
 it and turn it into blood. From or shortly after 
 parturition, there is a constant tendency of the 
 blood vessels in the udder to shrink in size, and 
 consequently a constantly diminishing flow of milk. 
 When the period of lactation advances at the same 
 time that the pastures are growing more scanty 
 and less succulent, this diminution is fairly regular 
 and constant, especially after from three to five 
 months of the period of lactation have passed. This 
 tendency to shrinkage in the size of the blood 
 vessels of the udder may be held in check in great 
 measure by an abundant supply of nutritious food, 
 particularly if it is of a succulent character, and 
 it is not at all uncommon to find cows secreting 
 milk in regular amount, or "holding out," for eight 
 
12 MiU- and Its Products. 
 
 or ten months. But in this respect the individ- 
 uality of the animal plays an important part, so 
 that wide variations are seen in different individ- 
 uals under the same conditions of food and care. 
 After a shrinkage in the flow has once taken place, 
 it is extremely difficult to again increase it by 
 increased food until after another calAdng. 
 
 Effect of succeeding pregnancy. — The effect of the 
 animal again becoming pregnant is to decrease the 
 flow of milk. The cause of this decrease seems, 
 in many cases, to be two-fold: First, a sympa- 
 thetic effect, following immediately upon conception, 
 and secondly, a shrinkage due to a turning away of 
 a part of the blood from the udder to nourish the 
 growing fcBtus. This shrinkage does not become 
 marked until the fourth or fifth month of preg- 
 nancy. In this respect, as in their power to "hold 
 out," individual animals show the widest variation. 
 With very many the effect of becoming again preg- 
 nant is so slight as to be scarcely noticeable ; with 
 others it is so great as to materially interfere with 
 the usefulness of the animal. 
 
 Incomplete removal of milk. — One of the most 
 important means of checking the secretion of milk 
 lies in the incomplete removal of milk already se- 
 creted. We have already seen that the removal 
 of the saline fluid from the ducts of the inactive 
 gland is an efficient stimulus to secretion. So, too, 
 the presence of milk in the duets acts as a check 
 to further secretion. Further than that, it not 
 only checks secretion but is an actual irritant, suffi- 
 
Regularity of Milking. 13 
 
 cient in many instances to give rise to inflammations 
 of a serious character. Clean milking is one of 
 the most important aids in keeping up and pro- 
 longing the flow of milk. 
 
 Regularity and frequency of milking. — While the 
 process of milk secretion is a continuous one, it is 
 not entirely uniform. There is reason to believe 
 that the secretion is considerably more rapid while 
 the operation of milking is going on, and that a con- 
 siderable portion of the whole amount is then secreted. 
 On the other hand, the distension of the milk ducts 
 and reservoirs by milk already secreted acts as more 
 or less of a check upon the activity of the follicles, 
 and so lessens the rapidity of secretion. While for 
 these reasons it would be inferred that frequent 
 milking would lead to increased secretion, the limits 
 of such increased secretion are' moderate, and beyond 
 a certain point no increased flow of milk is secured 
 by increasing the frequency of the milking periods. 
 In all cases where the udder becomes unduly dis- 
 tended with milk between periods, an increased flow 
 will be secured by milking oftener. The common 
 practice is to milk twice in the twenty -four hours, 
 and the nearer the time can be divided into equal pe- 
 riods the more uniform will be the secretion. Where 
 more frequent milking is practiced the same principle 
 will hold. Not only is regularity in the period from 
 morning to night of importance, but regularity in 
 the time of milking from day to day is equally so. 
 A difference of an hour in the time of milking will 
 frequently make a difference of 10 per cent in the 
 
14 Milk and Its Products. 
 
 amount secreted, and where these irregularities are 
 frequent, will soon result in a considerably diminished 
 flow. The amount of milk given is also considerably 
 affected by the way in which the milk is drawn. 
 In general, it may be said that rapid milking is con- 
 ducive to a large flow. In any event, the milk 
 should be drawn so that no discomfort is caused 
 the animal, and in this respect there is great dif- 
 ference in' milkers. A rapid, uniform stroke, with 
 a firm touch on the teat, and a stroking motion to 
 the lower part of the udder, gives the best results. 
 Babcock has found that certain milkers uniformly get 
 not only more but richer milk from the same cow. 
 Control of the animal over secretion. — The secre- 
 tion of milk is involuntary. The animal can no 
 more control it than it can control the respiration 
 or the circulation of the blood. Yet there are 
 numerous conditions of the animal that have a 
 more or less direct effect upon the secretion of milk. 
 These conditions have not only to do with the physi- 
 cal condition of the animal — as the supply of food, 
 the circulation of the blood, extremes of temperature, 
 etc. — but extend in large measure to the nervous 
 organization and condition of the animal. We have 
 already seen that the animal may by an exercise of 
 will more or less completely control the withdrawal 
 of milk already secreted ; so, too, there are nervous 
 conditions that have a great effect upon the actual 
 secretion. Sudden fright, an unfamiliar milker or 
 attendant, unusual excitement, sexual excitement, or 
 the presence of an animal in heat in the herd, an 
 
Physical Condition of Animal. 15 
 
 unusual amount of exercise, or any one of many 
 other causes, may be sufftcient to decrease the secre- 
 tion of milk one -half in any one day. The effect 
 of such disturbances is usually quickly overcome, but 
 their frequent recurrence leads to a permanent diminu- 
 tion of the secretion. The nerv6us organization 
 of the animal is a most important factor in deter- 
 mining the effect of these various disturbing influ- 
 ences. Many of the animals in which the powers of 
 digestion, nutrition and secretion are most highly de- 
 veloped are possessed also of a highly developed and 
 sensitive nervous system, and hence are easily affected 
 by any disturbing condition. With all such animals 
 it is of the utmost importance that every condition 
 surrounding the animal should be as regular and 
 uniform as possible. Other animals of equal capacity 
 show a remarkably quiet and phlegmatic nervous 
 temperament, and are consequently slightly or not at 
 all affected by such disturbing influences. Such an- 
 imals are of great value to the milk producer, for 
 with the utmost care and regularity there are always 
 disturbing influences beyond the control of the 
 dairyman. 
 
CHAPTER n. 
 
 COMPOSITION OF MILK. 
 
 The constituents of milk are numerous and of 
 diverse character, but may be easily classified into a 
 few well marked groups as follows: (a) water, (b) 
 fats, (c) substances containing nitrogen (albumi- 
 noids), (d) sugar, (e) ash. Excepting the water, they 
 are collectively known as milk solids. The solids 
 exist partly in solution, partly in semi -solution, and 
 partly in suspension in the water. Milk from the 
 various classes of animals has the same general 
 constitution and properties, and varies only in the 
 relative proportions of the various proximate con- 
 stituents. Cow's mUk is tj^pical of all milks, and as 
 it is the only milk used in processes of manufac- 
 ture in the United States, all of our discussions 
 have reference to it alone. In various other coun- 
 tries milk from the goat, ass, mare and ewe is con- 
 siderably used, not only as food but for the man- 
 ufacture of various products. Indeed the peculiar- 
 ities of some of these is supposed to be largely due 
 to their having been made from the milk of ani- 
 mals other than the cow. Koumiss, made from 
 mare's milk in Arabia, and Roquefort cheese, made 
 largely from ewe's milk, are noteworthy examples. 
 
 (16) 
 
Percentage Composition. 17 
 
 All of the milk constituents are more or less va- 
 riable in quantity, and manj- of them vary widely; 
 hence it is not possible to make a statement of the 
 average percentage composition of milk that will give 
 more than a general idea of its composition. The 
 following are taken from recent authorities in the 
 various countries: 
 
 American. English. German. French. 
 
 (Babcock.) (Oliver.) (FlHschmann.) (Cornevin.) 
 
 Water . . . 87.17 87.60 87.75 87.75 
 
 Pat . ... 3.69 3.25 3.40 3.30 
 
 Casein . 3.02 3.40 2.80 3.00 
 
 Albumin . . .53 .45 .70 
 
 Sugar . . . 4.88 4.55 4.60 4.80 
 
 Ash 71 .75 .75 .75 
 
 100.00 100.00 100.00 99.60 
 
 The following, from Kcenig, shows the range of 
 variation of the several constituents in nearly 800 
 analyses collected from all parts of the world: 
 
 Mo/xvmum. Minimum,. 
 
 Water 90.69 80.32 
 
 Fat . 6.47 1.67 
 
 Casein 4.23 1.79 
 
 Albumin 1.44 .25 
 
 Sugar 6.03 2.11 
 
 Ash ... 1.21 .35 
 
 While the range of variation shown above is 
 considerable, some of the constituents, notably the 
 fat, may show even greater ranges in milk secreted 
 by normal, healthy cows. It is probable that the 
 minimum of Kcenig is seldom exceeded, but as high 
 as 10 per cent of fat has been found in the milk 
 of single cows giving a very small quantity. Bab- 
 cock states that no analysis showing more than 9 
 
18 Milk and Its Products. 
 
 per cent of fat is recorded from any cow giving as 
 much as 15 pounds of milk per day. Any analysis 
 above 7 per cent is extremely rare, and should be 
 regarded with suspicion unless well authenticated. 
 The mixed milk of herds seldom falls below 3 per 
 cent of fat and rarely rises above 5.5 per cent. 
 
 Colostrum. — The first milk secreted by the animal 
 after parturition is quite distinct in composition and 
 physical properties from that produced after the 
 secretion has become well established. Such milk 
 is called colostrum, and is ordinarily considered 
 unfit for consumption or manufacture. Colostrum 
 differs from normal milk chiefly in its less proportion 
 of water and sugar, in the much greater proportion 
 of albumin and ash, in the extremely variable amount 
 of fat, and in the presence of small organized bodies 
 known as colostrum corpuscles, which are probably 
 debris of the cell structure of the gland. The follow- 
 ing analyses from Richmond after Vaudin show the 
 extremely variable composition of colostrum: 
 
 No. 1. No. g. 
 
 Water . 72.39 75.51 
 
 Pat 1.30 6.32 
 
 Sugar 1.52 2.17 
 
 Proteids (casein, albumin, etc.) 23.70 U.91 
 
 Ash .1.09 1.09 
 
 100.00 100.00 
 
 The percentage of albumin in colostrum is so 
 great that it will cause the whole mass of milk to 
 thicken upon boiling, and this is ordinarily consid- 
 ered a sufficient test for determining the suitability 
 of the milk for consumption or manufacture. With- 
 
Specific Gravity of Milk. 19 
 
 in four or five days after calving, the milk loses its 
 colostrum character and takes on its normal condi- 
 tion. This change is a gradual and progressive one, 
 and is more or less dependent upon the physical 
 condition of the animal. When the cow is feverish, 
 or when there is local inflammation in the udder, 
 the colostrum character of the milk is retained 
 for a longer period than otherwise. The amount 
 of coloring matter present is also considerably 
 greater in colostrum than in normal milk, and the 
 percentage of fat varies very widely. Usually the 
 percentage of fat is less in the colostrum than in 
 the normal milk from the same cow, although oc- 
 casions are not infrequent where more fat is found 
 in the milk immediately after calving than at any 
 other time in the whole period of lactation. 
 
 Specific gravity of milk. — Some of the solids of 
 milk are heavier than water and some of them lighter, 
 milk as a whole having a specific gravity somewhat 
 greater than water. The variation in the specific 
 gravity is considerable, the range usually given being 
 from 1.029 to 1.035 at 60° F., the average being 
 about 1.032. In general, the effect of an increase 
 in the solids of the milk is to increase its specific 
 gravity, though in milk extremely rich in fats (6 
 per cent or above) the specific gravity is lessened. 
 Formerly, more than at present, it was the custom 
 to estimate the quality of the milk by determining 
 its specific gravity, but as soon as it became known 
 that the specific gravity depended not so much upon 
 the amount as upon the character of the solids, a 
 
20 Milk and Its Products. 
 
 determination of the specific gravity became of little 
 value. Unscrupulous dairymen soon learned that 
 water could be added to milk and fat or cream 
 taken from it in such proportions that the specific 
 gravity would remain the same as that of normal 
 milk. 
 
 The fats.— The fat of milk, or butter fat, as it 
 is often called, is a mixture of a considerable number 
 of separate and distinct fats, no less than six or 
 eight being normal to milk, and a considerable fur- 
 ther number may be present under various conditions. 
 The fats in milk are of two kinds, volatile and non- 
 volatile. To the former class belong the various 
 normal essential oils that give to milk and butter 
 their characteristic odors and flavors, and in addition 
 to these normal fats there may be a large number 
 of volatile oils that are present in the food of the 
 cow, and that impart to the milk the characteristic 
 flavors of such foods. ' 
 
 The volatile /a<s.— The volatile fats make up only 
 a small part of the total milk fat ; in general, prob- 
 ably about 15 pei- cent of the whole. The chief 
 normal volatile fats are butyrin, caprin, caproin, 
 caprilin and laurin. Of these, butyrin is in much 
 the largest proportion and of much the greatest im- 
 portance. It is the chief volatile fat of milk and 
 butter, and to it are due in large part the character- 
 istic flavors and aromas of milk and butter. Butyrin 
 readily decomposes, forming butyric acid, which is the 
 chief element in the rancid or " frowy " taste that 
 butter acquires upon long standing. 
 
Effect of Strong -flavored Foods. 21 
 
 The volatile fats that are derived directly from 
 the food may give either desirable or undesirable 
 flavors to the milk. Thus we esteem the character- 
 istic flavors due to the grasses, -clover and like fodder; 
 on the other hand, the stronger flavors of garlic, 
 onions, turnips, cabbage, etc., give to the milk an 
 undesirable character. 
 
 The presence of these undesirable flavors in milk 
 is often a source of a good deal of annoyance, but 
 with proper precautions the bad results coming from 
 them may be greatly lessened, and in many cases 
 entirely obviated. Since all of these flavoring oils are 
 volatile, they easily pass through all the tissues of 
 the animal, and in a comparatively short time pass 
 off through the various excretory channels. We shall 
 find them present in the greatest amount not only 
 in the milk, but in all the tissues of the animal, 
 during the time that the fodder containing them is 
 undergoing digestion, and by the time the digestion 
 is completed the volatile products will have almost 
 entirely passed away. If, therefore, sufficient care 
 is taken to so time the feeding and milking that the 
 milk shall be drawn not less than ten or twelve 
 hours after the undesirable fodder has been eaten, 
 there will be slight danger of contamination of the 
 milk by it. Whereas, if milking occurs within three 
 or four hours after feeding, the milk will be 
 strongly impregnated with the undesirable flavor. 
 Taking advantage of this, and feeding cows immedi- 
 ately before or immediately after milking, dairymen 
 are often enabled to feed large quantities of turnips. 
 
22 Milh and Its Products. 
 
 and even onions, without danger of contamination of 
 the milk. The presence of wild garlic and wild 
 onions in pastures is a source of bad flavor in the 
 milk in a considerable -portion of the country. Where 
 this is the case it is, of course, more difficult to 
 overcome the bad flavor ; but by allowing the cows 
 to pasture for a comparatively short time only im- 
 mediately after milking, and keeping them up and 
 giving them some dry food for three or four hours 
 before milking, there will be a great deal less an- 
 noyance from this source. 
 
 The non-volatile fats. — The non-volatile fats make 
 up about 85 per cent of the whole amount of fat, 
 and consist of a more or less uncertain and variable 
 mixture of several fats, of which olein and palmitin 
 make up the chief part. They are glycerides of the 
 corresponding fatty acids — oleic, palmitic, stearic, myr- 
 istic, etc., and differ from one another chiefly in 
 their hardness or melting point. Olein is liquid at 
 ordinary temperatures ; palmitin and the others are 
 solid. Olein melts at about 41° F., the hard fats at 
 various temperatures from 130° to 150° F. The 
 mixture of the whole, as we find them in ordinary 
 butter, melts at from 92° to 96° F. The hardness 
 or softness of different butters, depending largely 
 upon varying proportions of olein. Considerable doubt 
 exists as to the relative proportions of the various 
 fats and fatty acids. Browne* gives the following 
 percentages of volatile and non- volatile fatty acids: 
 
 *Jour. Am. Chem. Soc. 21, 823. 
 
The Non-volatile Fats 23 
 
 Oleic 33.95 
 
 Palmitic 40.51 
 
 Myristie . . . 10.44 
 
 Stearic ... . . 1.91 
 
 Dioxystearie 1.04 
 
 Butyric 6.23 
 
 Laurie 2.73 
 
 Caprole 2.32 
 
 Caprylic 53 
 
 Capric 34 
 
 100.00 
 
 It is asserted that the coloring matter of the 
 fat is most intimately associated with the palmitin. 
 The fat exists in the milk in the form of an emul- 
 sion of extremely small globules, varying in size 
 from is'ou to ^ 5000 of an inch in diameter. These 
 globules are not surrounded by pellicles, or so- 
 called skins, as was formerly thought, but main- 
 tain their form by reason of the surface tension of 
 the liquid fat, and also to some extent because of 
 a layer of more or less condensed casein that im- 
 mediately surrounds them. The permanency of the 
 emulsion is further increased by the viscous nature 
 of the milk serum, due to the presence of sugar 
 and other solids in solution. 
 
 The albuminoids. — The casein is the chief albu- 
 minoid of milk, although there is always present a 
 small amount of albumin, and, according to some 
 authorities, of fibrin. Casein is of prime impor- 
 tance in the manufacture of cheese, and it is the 
 chief constituent that goes to form tissue when milk 
 is used as a food. 
 
 There is a good deal of doubt as to the form 
 
24 Milk and lis Products. 
 
 in which the casein exists. Formerly it was sup- 
 posed that the casein is in solution. This idea 
 was brought about by the fact that it is impossible 
 to filter the casein from the milk, even though it 
 is passed through several thicknesses of fine paper. 
 Later, though, it was found that when milk is 
 passed through a fine porcelain filter a certain part 
 is removed, and it was then supposed that there 
 were two forms of casein, one of which was in 
 solution and the other in suspension in very fine 
 particles of a colloidal or gummy character. Still 
 later investigations have shown that in all proba- 
 bility a large part of the casein is in this extremely 
 fine colloidal state. When milk is subjected to 
 the action of weak organic or mineral acids, to 
 rennet or to certain vegetable substances, the casein 
 is precipitated in a flocculent mass. Casein is not 
 acted upon by heat. The albumiin of the milk is 
 in all respects similar to blood albumin. It is 
 rendered insoluble by a heat of about 180° F., but 
 it is not acted upon by weak acids or rennet, and 
 in this way it is chiefly distinguished from the 
 casein. The fibrin of milk, if present, is in ex- 
 tremely minute quantities. It is supposed to be 
 the same as blood fibrin, and coagulates upon ex- 
 posure to the air, but is never present in sufficient 
 quantity to form a clot, as in the case of blood. 
 Its coagulation is hindered by a reduction of tem- 
 perature, and it has been supposed that when it does 
 coagulate it forms a sort of network of threads 
 through the mass of milk. 
 
Milk Sugar and Ash 25 
 
 The sugar. — Milk sugar, otherwise called lactose, 
 exists in solution in the milk serum. It has the 
 same chemical composition as cane sugar : that is, 
 C12H22O11 + H2O. It crystallizes with considerable 
 difficulty, and has very much less sweetening power 
 than ordinary sugar. Under the influence of vari- 
 ous ferments it readily undergoes decomposition, 
 each molecule of sugar breaking up into four mol- 
 ecules of lactic acid. This change begins in the 
 milk almost immediately after it is drawn, and con- 
 tinues until from .8 to 1 per cent of lactic acid 
 is formed. The presence of lactic acid in this 
 amount acts as a check upon the growth of the 
 ferments, and prevents the further formation of 
 lactic acid, unless the acid is neutralized with an 
 alkali, when the fermentation proceeds as before. 
 Milk sugar does not readily undergo alcoholic fer- 
 mentation, but by the action of yeast and some 
 other ferments the lactose is "inverted," or changed 
 to dextrose and a peculiar substance known as ga- 
 lactose, and these readily change to alcohol undei 
 the influence of the proper ferments. 
 
 The ash. — The ash is the smallest and least 
 variable constituent of the milk. It is composed 
 chiefly of the phosphates of lime and potash, the 
 chlorides of potash and soda, with small amounts 
 of phosphate of iron and magnesia. Most of the 
 salts are in solution. It seems probable that at 
 least a part of the phosphate of lime is ordinarily 
 in insoluble form, suspended in the milk in very 
 flue particles in connection with the casein. The 
 
26 Milh and Its Products. 
 
 chloride of potash is largely in excess of the 
 chloride of soda. This is exactly opposite to the 
 proportions of these two salts in the blood. 
 
 Other constituents. — Besides the constituents enu- 
 merated above, several other compounds are more or 
 less normally present in milk in minute quan- 
 tities. 
 
 A small amount of citric acid is said to be a 
 normal constituent of milk. 
 
 A peculiar substance called lactochrome is also 
 a normal constituent of milk, and gives to it its 
 characteristic color. This has been already men- 
 tioned in connection with the palmitin. The amount 
 of lactochrome present varies under many condi- 
 tions, notably the breed of the animal and the 
 character of the food. Whatever other conditions 
 may prevail, the milk is always of a higher color 
 where the animals are fed on fresh green forage. 
 This has led to the idea that the color of the 
 milk is in some way connected with the condition 
 of the ehlorophyl or green coloring matter of the 
 plant. Care no* has suggested that as the ehloro- 
 phyl undergoes a change when the plant is dried, 
 the digestive organs of the animal will have a 
 different effect upon it, and so account for the 
 difference in color in the milk. 
 
 An albuminoid called lactoprotein has also been 
 described in milk. 
 
 Urea to the extent of .001 of 1 per cent may 
 also be regarded as a normal constituent of milk. 
 
 * Milch Zeitnng, vol. xxlv. 387. 
 
Variations in Quality. 27 
 
 Variations in quality of milk. — "We have already 
 seen that the amount of milk secreted may vary 
 greatly under the influence of a large number of 
 varying conditions. So, too, we find that there 
 are a large number of conditions that affect the 
 quality of the milk, meaning thereby the relative 
 proportion of the various constituents, and particu- 
 larly the proportion of fat to other constituents. 
 Some of these changes are regular and progressive 
 during the period of lactation. Others are due to 
 definite causes, and still others occur from time to 
 time to which we have as yet been unable to 
 ascribe any definite cause. After about the third 
 or fourth week of lactation the percentage of fat 
 in the milk remains nearly constant until the seventh 
 or eighth month, or until the quantity of milk begins 
 to rapidly diminish ; but while the percentage of fat 
 does not markedly change, the character of the fat 
 undergoes several marked and characteristic changes. 
 The butter globules are largest in size early in the 
 period of lactation, and constantly diminish as lac- 
 tation progresses, at the same time that they in- 
 crease in number, so that the total amount of fat 
 is not greatly changed. Early in the period of lac- 
 tation there is a larger proportion of olein. In 
 some eases it may amount to 50 per cent of the 
 total fat. As the lactation progresses the propor- 
 tion of olein decreases and stearin and palmitin in- 
 creases, until the proportion of olein may fall as low 
 as 20 per cent. This change is more marked when 
 the animal changes from fresh to dry food, as the 
 
28 Milk and Its Products. 
 
 period of lactation progresses. The hardening of 
 the fat and the shrinking in the size of the glob- 
 ules are also more marked when the animal again 
 becomes pregnant. In the case of cows that are 
 milked for a prolonged period, as sometimes hap- 
 pens with farrow and spayed cows, the milk often 
 becomes abnormally rich, not only in fat, but in 
 casein ; and in such cases the fat is usually made 
 up of very minute globules. 
 
 It is usually observed that milks drawn at 
 night and morning differ quite widely in the per- 
 centage of fat. This is not because there is any 
 difference in the milk secreted by night or by daj', 
 although when cows lie still there is a larger per- 
 centage of water and a correspondingly less per- 
 centage of solids in the milk. The difference in 
 the milk drawn at morning and evening is due to 
 the unequal time that elapses between the periods. 
 In general, the milk is richest in fat that is drawn 
 after the shortest period, and this has been shown 
 to be the case where cows have been milked three 
 or four and even five times per day. It is, 
 however, not an invariable rule that the mUk is 
 richest succeeding the shortest period. Not infre- 
 quently it has been found that the milk is richer 
 after the longer period. In a series of observa- 
 tions made by the writer upon 12 cows, ex- 
 tending over 221 days, in 72 cases the percentage 
 of fat was greater in the morning ; in 114^ cases 
 it was greater in the evening, and in 35 cases 
 there was a difference of .1 of 1 per cent or less 
 
First and Last Milk Drawn. 29 
 
 oetween the morning and the evening milk. In this 
 instance the period from evening to morning was 
 about two hours longer. The amount of variation 
 that may occur between the morning and evening milk 
 is often very considerable. In the great majority 
 of cases it is not more than .5 of 1 per cent, 
 but variations so great as 2 or 2.5 per cent be- 
 tween the milk of one morning and that of the 
 preceding or following evening have frequently 
 been noticed. It is probable that a part of this 
 variation may be explained by the action of the 
 lymphatics of the udder in reabsorbing a part of 
 the fat when the milk remains for a long time 
 in the vessels of the udder. 
 
 There is also a considerable variation in the 
 milk from day to day. This is usually not so 
 great as between the morning and evening milking, 
 but it not infrequently amounts to 1 per cent. 
 Such daily variations may be ascribed to changes 
 in the climate or other environment of the cows, — 
 the effect of storms, the effect of change of food, 
 the effect of slight indispositions, etc.; but there 
 are numerous conditions not usually or readily 
 recognized by the owner that affect the composition 
 of the milk. It has been noted in many instances 
 that the normal effect of a slight febrile condition 
 of the animal is to largely increase the percentage 
 of fat and albumin. If the febrile condition con- 
 tinues, and particularly if it grows more severe, 
 the fat then falls as quickly as it had risen, and 
 to a correspondingly lower point. 
 
30 Milk and Its Products. 
 
 The variatioa in the percentage of fat in the 
 milk first and last drawn is very great. The first 
 milk drawn is much the poorer in fat. Differ- 
 ences so wide as 1 and 10 per cent of fat in 
 the first and last few pints have not infrequently 
 been noticed. This is due in large measure to the 
 fact that the larger globules of fat, being of 
 nearly the same size as the smaller milk ducts, 
 pass along these vessels less readily than the more 
 fluid portions of the milk, and are only drawn 
 out with the last milk drawn. The milk first 
 drawn has been in the milk cisterns and larger 
 vessels for a considerable period of time, and so 
 has been subject to the reabsorptive action of the 
 lymphatics for a longer time, which also would 
 tend to make it poorer in fat. 
 
 The food also has a considerable influence upon 
 the quality of the milk, although the quantity of 
 the milk is more easily affected by changes in the 
 amount and character of the food than is quality. 
 In fact, with cows kept under favorable conditions, 
 with an abundant supply of food, it is hardly 
 possible to increase the proportion of fat to other 
 solids by a change in the food. On the other band, 
 while the amount of the various constituents of 
 the milk is not easily affected by the food, the 
 quality of the constituents themselves may be 
 considerably influenced, notably in the case of the 
 fat. Certain foods have a marked influence upon 
 the character of 'the milk fat. Thus linseed meal, 
 gluten meal and certain other foods make a soft. 
 
Relation of Fat to Casein 31 
 
 oily fat, while cotton -seed meal, the seeds of the 
 various legumes and wheat bran make a hard fat. 
 Constituents other than the fat are not so readily 
 affected in this way. 
 
 Of the constituents of milk, the ash and the 
 sugar are the least variable, the fat and albumin 
 the most variable, while the casein usually bears a 
 nearly constant ratio to the fat. The percentage 
 of water also varies considerably. The causes of 
 the variation of the fat have already been noticed. 
 The proportion of albumin is very largely in- 
 fluenced by the physical condition of the cow, and 
 it has been shown, notably by Van Slyke (see 
 Chapter X ), that with what may be called normal 
 milk, — that is, milk containing from 3 to 4.5 per 
 cent of fat, — the proportion of casein rises or falls 
 in almost exact ratio with the fat, but when the 
 fat rises above this point the casein does not 
 follow in the same proportion. 
 
 A notion is prevalent that the percentage of fat 
 in the milk is also affected by the age of the cow; 
 that during the first and second periods of lactation 
 the young cow usually gives milk poorer in fat 
 than when she is mature. During the years of 
 greatest vigor the percentage of fat is supposed to 
 be fairly uniform ; but in cows of advanced age it 
 may sometimes again fall to a low point. Recently 
 some records have been published* that go to show 
 that the age of the cow has little, if any, influence 
 
 *HolBtem Friesian Herd Book, vols. 13, 14, 15, 16, 17. Cornell University 
 Agr. Expt. Station, BulleVn No. l§?, 
 
32 Milk and Its Products. 
 
 on the percentage of fat in the milk. In the one 
 case the observations were made upon a large num- 
 ber of cows of all ages, for a week at a time, com- 
 paratively early in the period of lactation. In the 
 other the observations were made upon a single herd 
 extending over several years, and the percentages of 
 fat are the average for the whole period of lactation. 
 The percentages of fat for the different ages are as 
 follows : 
 
 " Official " weekly tests of Observations on Cornell 
 
 
 Holstein-Friesian cows. 
 
 University herd, 1831-8. 
 
 
 No. 
 
 Average 
 
 No. 
 
 Average 
 
 
 of Cows. 
 
 per cent fat. 
 
 of Cows. 
 
 per cent fat. 
 
 2-year-olds . 
 
 . 147 
 
 3.29 
 
 25 
 
 3.71 
 
 3-year-olds 
 
 81 
 
 3.31 
 
 25 
 
 3.71 
 
 4-year-olds 
 
 59 
 
 3.41 
 
 38 
 
 3.68 
 
 5-year-olds 
 
 . 37 
 
 3.42 
 
 12 
 
 3.60 
 
 e-year-olds 
 
 36 
 
 3.34 
 
 8 
 
 3.49 
 
 7-year-olds . . 
 
 22 
 
 3.25 
 
 5 
 
 3.68 
 
 8-year-olds . . 
 9-year-olds 
 
 . li 
 10 
 
 3.40"! 
 3.37/ 
 
 4 
 
 3.89 
 
 10-year-olds 
 
 9 
 
 3.83 
 
 
 
 11- and 12-year-olds 
 
 4 
 
 3.57 
 
 
 
 The breed of the cow also influences very largely 
 the percentage of fat in the milk. Cows of certain 
 breeds normally give milk much richer in fat than 
 others. 
 
 The following, compiled from a large number 
 of analyses made at various American Agricultural 
 Experiment Stations, will give a general idea of 
 the average composition of the milk of the more 
 common breeds, so far as it relates to total solids 
 and fat: 
 
New York btate Uollege of Agricu 
 LIBRARY. 
 Milk of Different Breeds. 33 
 
 Solids. Fat. 
 
 Jersey 14.70 5.35 
 
 Guernsey 14.71 5.16 
 
 Devon 14.50 4.60 
 
 Short-horn 13.38 4.05 
 
 Ayrshire 12.61 3.66 
 
 Holstein-Friesian 11.85 3.42 
 
 The variation due to breed includes not only the 
 amount of fat, and the color and melting point of 
 the fat, but the size of the milk globules. In some 
 breeds the milk globules are uniformly large, in 
 others extremely small, and in still others both large 
 and small globules are found. 
 
 While there is a distinct difference in the qual- 
 ity of the milk of the different breeds, the dif- 
 ferent individuals in the breed also vary largely in 
 the quality of the milk. The difference in the 
 percentage of fat in milk from different cows of 
 the same breed is quite as great as the average 
 differences between the breeds ; that is to say, the 
 difference between the highest and lowest percent- 
 age of fat in the milk of different individuals of 
 the same breed is as great as the difference be- 
 tween the average percentage of fat in the breeds 
 giving the richest and poorest milk. 
 
 The variations due to the breed of the animal 
 extend, of course, in some measure to the butter 
 made from the milk. This is particularly true of 
 the color and hardness of the fat. But while 
 these differences are sufilcient in amount to be 
 characteristic, they scarcely affect the quality of 
 the butter as a whole. While some partisans may 
 
34 Milk and Its Products. 
 
 contend that the butter made by their favorite breed 
 is of superior quality, it would be well-nigh impos- 
 sible, in any given case, by an examination of the 
 butter, to say from what breed of cows it had 
 been made. Butter of the very best quality in tex- 
 ture, color and flavor may be made from the milk 
 of any breed of cows. 
 
CHAPTER IIL 
 
 THE TESTING OF MILK. 
 
 Milk is so variable in composition, and so ea- 
 sily adulterated, that it frequently becomes of great 
 importance to be able to ascertain with a fair de- 
 gree of accuracy the composition of any given 
 sample. 
 
 HISTORY OF MILK TESTS. 
 
 Gravimetric analysis. — The most accurate way to 
 determine the composition of milk is by means of an 
 exact chemical analysis. The constituents of milk 
 which it is most frequently necessary to determine 
 are the total solids and fat. The total solids are 
 determined by drying an accurately weighed portion 
 of the milk at the temperature of boiling water 
 until it no longer loses weight. The residue is the 
 total solids, and its weight, divided by the weight 
 of the original amount taken, will give the percent- 
 age of total solids. The fats may then be deter- 
 mined by extracting the residue with anhydrous 
 ether until nothing more is dissolved, and then 
 evaporating the ether and weighing the resulting 
 fat directly. Various forms of apparatus for mak- 
 ing these determinations have been devised by vari- 
 
 (35) 
 
36 Milk and Its Products. 
 
 ous chemists, a considerable number of which give 
 very accurate results. Chief among these methods 
 for determining fat and total solids are the Babcock 
 asbestos method and the Adams paper -coil method. 
 In order that these determinations may be made 
 with accuracy, balances of extreme delicacy, and 
 apparatus more or less complicated and requiring 
 considerable skUl in its manipulation, are necessary, 
 so that for ordinary commercial purposes they are 
 practically out of reach. 
 
 History of milk tests. — Although consumers of 
 milk had felt for a long time the necessity of 
 some means of protection against dishonest dealers, 
 it was not until the development of the factory sys- 
 tem of manufacturing cheese (1850) and butter 
 (1870) that some means of easily determining the 
 composition of mUk, particularly as to fat content, 
 became important to both producers and manufac- 
 turers. From that time on various methods have 
 been devised, from the simple expedient of raising 
 the cream in a small sample of mUk in a graduated 
 glass to apparatuses almost as complicated and 
 difilcult of manipulation as the gi-avimetric methods 
 themselves. 
 
 Cream gauges.— The simplest and one of the 
 earliest methods used to determine the quality of 
 milk is to set a small portion of it under such con- 
 ditions that the cream would be thoroughly thrown 
 to the surface and easily measured. These were 
 known as cream glasses, cream gauges, or cream- 
 ometers, and to a certain extent served a useful pur- 
 
Lactometers. 37 
 
 pose ; but it was soon found that the percentage of 
 cream depends not so much upon the amount of fat 
 present in the milk as upon the size of the globules 
 and the conditions under which they are brought 
 to the surface, and that the percentage of cream 
 does not necessarily bear a constant relation to the 
 percentage of fat. 
 
 Specific gravity. — The determination of the spe- 
 cific gravity was next brought into use as a means 
 of determining the quality of milk. Inasmuch as 
 milk is slightly heavier than water, and as water is 
 the most common adulterant of milk, any addition 
 of water to it would serve to lessen , its specific 
 gravity, and would easily be detected by a determi- 
 nation of the specific gravity. To determine the 
 specific gravity of milk, various forms of specific 
 gravity hydrometers, known as lactometers, have 
 been devised. They were formerly very much more 
 depended upon as a test of the quality of milk than 
 at present, and though now we have learned that 
 under certain conditions a simple specific gravity 
 test may not only be inaccurate, but entirely mis- 
 leading, still they are of cojisiderable use for cer- 
 tain purposes and in connection with certain other 
 instruments. 
 
 Lactometers .—In devising the lactometer, it was as- 
 sumed that 1.029 was as low as the specific gravity of 
 any unadulterated milk would ever fall ; therefore a 
 hydrometer was devised, the scale of which was gradu- 
 ated from to 120, the marking the point of pure 
 water, or a specific gravity of 1.000, and 100 cor- 
 
38 
 
 Milh and Its Products. 
 
 responding to the 
 milk, or 1.029. 
 If, then, in any 
 given sample of 
 milk the lactom- 
 eter fell to 90, 
 it would indicate 
 the presence of 10 
 per cent of water ; 
 if it fell to 75, of 
 25 per cent of 
 water, etc. This 
 form of lactometer 
 is now known as 
 the common, or- 
 dinary or Board 
 of Health lactom- 
 eter. A second 
 form of lactometer 
 in common use ' 
 was devised by 
 Quevenne, and 
 bears his name. 
 The scale of this 
 hydrometer is or- 
 dinarily graduated 
 from 15 to 40, the 
 29 being coinci- 
 dent with 100 up- 
 
 assumed least specific gravity of 
 
 ABC 
 
 on the Ordmary lac- ^jg 2. comparison of graduation on lactometer 
 triTriptpr and -vpitli stems : J., hydrometer •£, ordinary lactometer! 
 IOmeter ana Wlin O, Quevenne lactometer. 
 
Relation of Quevenne to Ordinary Lactometer. 39 
 
 a specific gravity of 1.029 upon the ordinary hy- 
 drometer. The accompanyihg sketch (see opposite 
 page) shows the relative -rakms of the degrees upon 
 the ordinary hydrometer, tlH|[^inary lactometer and 
 the Quevenne lactometer. With the Quevenne lac- 
 tometer the specific gravity of the milk can be at 
 once read, a degree upon this scale being equivalent 
 to one degree of specific 'gravity. Since 100 degrees 
 upon the ordinary lactometer indicate a specific gravity 
 of 1.029; the specific gravity of any ordinary lactometer 
 reading may be obtained by multiplying the reading by 
 .29, dividing by 1,000 and adding 1. Twenty-nine Que- 
 venne degrees are also equivalent to 100 ordinary de- 
 grees, so that Quevenne readings may be changed to the 
 ordinary readings by dividing by .29, and ordinary 
 readings may be changed to Quevenne readings by 
 multiplying by .29. 
 
 The relative density of milk varies with its tem- 
 perature, so that a hydrometer is only correct at one 
 given temperature. Most hydrometers are graduated 
 for a temperature of 60° F., and the better forms 
 have an attached thermometer ; so that if the milk 
 to be tested varies from this in either direction a cor- 
 rection must be made. As the density increases with 
 a reduction of temperature and decreases with a rise 
 of temperature, the correction must be subtracted in 
 going from a lower to a higher and added in going from 
 a higher to a lower temperature. The amount of such 
 correction for the Quevenne lactometer is .1 of a lac- 
 tometer degree for each degree of temperature, and for 
 the ordinary lactometer one lactometer degree for each 3 
 
4(1 Milk and Its Products. 
 
 degrees of temperature. In no event should the 
 temperature of the milk to be tested be more than 10 
 degrees warmer or coldg^han the standard, and it is 
 much better if the teiiPwature does not vary from 
 the standard more than 5 degrees in either direction. 
 The solids in milk are not all of the same 
 specific gravity ; some are heavier and some lighter 
 than water. The fats are lighter, the other solids 
 are all heavier. The specific gravity of the milk, 
 then, depends not only upon the amount of solids 
 present in the mUk, but also upon their relative 
 proportions. The specific gravity of milk may be 
 affected by the addition of any substance to it or 
 the abstraction of any of its constituents. Since 
 some of the constituents of milk are lighter than 
 water, their abstraction in whole or in part would be 
 followed by an increase in density. It will be 
 readily seen, then, that if a part of the fats are re- 
 moved, the specific gravity of the skimmed or partly 
 skimmed milk will be heavier than normal, and the 
 addition of a certain amount of water or other sub- 
 stance lighter than the milk would only serve to 
 bring the specific gravity back to the normal point. 
 In this way, if it is done skUfully, water may be 
 added to milk, and cream abstracted from it, with- 
 out affecting the specific gravity as revealed by the 
 lactometer, and a very inferior sample of mUk might 
 pass as perfectly normal if the lactometer alone 
 were depended upon for its detection. Mainly for 
 this reason the lactometer has been superseded by 
 other and more accurate instruments. 
 
Operation of Test Churns. 41 
 
 Churn tests. — The first butter factories or cream- 
 eries were managed upon what is known as the 
 cream -gathering system : that is, the cream was 
 raised and skimmed upon the farm, and it alone 
 taken to the factory. It was soon found that the 
 cream varied considerably in the percentage of fat 
 that it contained, and, moreover, that a consider- 
 able amount of milk could be mixed with the 
 cream without being detected by ordinary means. 
 In other words, the managers of factories learned 
 that cream as it came to them was even more 
 variable in its percentage of fat than whole milk. 
 In all of the earlier factories the cream was paid 
 for simply by measure, and it became necessary to 
 devise some means of making an equitable division 
 among the different patrons, and of protecting the 
 factory from loss. To do this, what was known 
 as test churns were devised. At the time of 
 gathering the cream, a small sample ( a pint or 
 quart) of each patron's cream was taken in a sep- 
 arate vessel. These were taken to the factory 
 and churned separately in small tin cans, and the 
 butter made up from each. The butter -producing 
 power of the single pint or quart was taken as a 
 measure of the butter value of the whole amount 
 of that patron's cream, and the proceeds were ap- 
 portioned accordingly. This method was much more 
 just than a simple measure of the cream, but it 
 was very cumbersome. It required delicate manip- 
 ulation in order to make all of the little pats of 
 butter of the same water content, and the small 
 
42 Milk and Its Products. 
 
 amounts of butter so made were of inferior com- 
 mercial quality, could not be mixed with the whole 
 mass of butter, and entailed a considerable loss 
 upon the creamery. 
 
 The oil -test churn was an outgrowth of this 
 method, intended to remedy its defects, and was in 
 a great measure successful. In operating the oil -test 
 churn, the individual samples taken from each patron 
 were very much smaller, and were taken in small 
 glass tubes. These tubes were put in a frame and 
 agitated until the fat was drawn together in a solid 
 mass ; the tubes were then immersed in water suf- 
 ficiently warmed to melt the fat, and when so 
 melted the fat would float upon the surface of the 
 liquid in the tube. The tubes were allowed to 
 become cool, were then a second time agitated to 
 churn any particles of fat that had escaped the 
 first churning, and the fat remelted ; it then ap- 
 peared in the form of a clear layer of liquid upon 
 the top of the contents of the tube, and could be 
 readily measured. The proportion of melted fat 
 so obtained was taken as a measure of the butter 
 value of the cream of which it was a sample. 
 This test was generally used in cream -gathering 
 factories, and was a very fair measure of the 
 butter value of the cream. There was always a 
 portion of the fat remaining unchurned, but in 
 cream it was a small percentage. In milk, how- 
 ever, it was a much larger proportion, and the 
 oil -test churn was never successfully used for de- 
 termining fat in milk. 
 
Lactolutyromeier and Pioscope. 43 
 
 Inventions for testing milk. — Several instruments 
 of European invention have been described for the 
 quick determination of the fat in milk. Some of 
 them make volumetric determinations of the fat or 
 cream ; others depend simply upon the opacity of 
 the milk. One or two are in common use in 
 Germany and Denmark, but, though most of them 
 have been introduced in the United States, none 
 have come into general use. The more important 
 of these are the following : 
 
 Marchand's lactobutyrometer. — This is an instru- 
 ment for quickly determining, volumetrically, the 
 fat in milk. A measured sample of milk is intro- 
 duced into a long glass tube graduated at the 
 upper end. A certain amount of acetic acid is 
 added and thoroughly mixed with the milk, after 
 which ether is added to dissolve the fat, and with 
 the aid of a small amount of heat the fat is col- 
 lected into the upper graduated portion of the tube 
 and read off volumetrically. The lactobutyrometer 
 was introduced about 1877, and was used with 
 more or less success for a time. In certain sam- 
 ples of milk it was found to be difficult to get a 
 clear separation of the fat, and in certain other 
 samples, notably the milk produced from various 
 foods, it was found that the results could not be 
 relied upon. 
 
 Heeren's pioscope. — This is a simple little instru- 
 ment designed to test the quality of milk by 
 means of its opacity. It consists of a hard rubber 
 disc, in the center of which is a small depression, 
 
44 Milk and Its Products. 
 
 and the surrounding circle painted in segments of 
 varying shades to represent cream, very rich milk, 
 normal milk, poor milk, etc. A drop of the milk 
 to be tested is placed in the central depression 
 and covered with a glass plate, so that a layer of 
 uniform thickness is always obtained. The opacity 
 of this drop of milk upon the black background 
 of rubber is then compared with a corresponding 
 segment of the circle. In so far as the fat 
 measures the opacity of the milk, this is a fairly 
 reliable test ; and, used in connection with a specific 
 gravity lactometer, a person with some experience 
 can readily detect suspected samples of milk, although, 
 of course, it is not possible to estimate very closely 
 the amount of adulteration or the quality of the 
 milk. The pioscope has been used very generally 
 and successfully by milk inspectors and those hav- 
 ing the control of city milk supply. 
 
 Feser's lactoscope is another instrument designed 
 to determine the quality of milk by opacity. It 
 consists of a glass cylinder, in the center of which 
 is fixed a white rod graduated with black lines. 
 A certain amount of milk is put into the cylinder, 
 and by its opacity renders the black lines upon 
 the central standard invisible. Water is then added 
 to the milk in measured quantity until the black 
 lines can be seen, the amount of water so added 
 indicating the quality of the milk. This instru- 
 ment is more delicate than the pioscope, but it can 
 not be so quickly and readily used. The results 
 it gives are of very much the same nature and 
 
Various European Tests. 45 
 
 value as those obtained by the use of the pioscope, 
 consequently it has never been used to any great 
 extent. 
 
 Soxhlet's method. — In testing milk by this method, 
 the fat in a measured quantity of milk is dissolved 
 in ether, the specific gravity of the ether solution 
 determined, and from this the percentage of fat is 
 calculated. The greater the specific gravity of the 
 ether solution the greater the percentage of fat, 
 and since the difference in the specific gravity of 
 fat and ether is considerable, the addition of a 
 small amount of fat will perceptibly affect the specific 
 gravity, so that the determination is a very delicate 
 one. The determination is made in a specially de- 
 vised apparatus known as Soxhlet's Aerometer. It 
 has been widely adopted in Germany, but not at all 
 in the United States outside of chemical labora- 
 tories. 
 
 DeLaval lactocrite. — This is a machine devised by 
 the inventor of the centrifugal separator to esti- 
 mate the fat in milk volumetrically. The sample 
 to be tested is put in a glass tube with an equal 
 amount of concentrated acetic acid containing 5 per 
 cent of concentrated sulphuric acid, and the mixture 
 heated for a few minutes, after which it is whirled 
 in a centrifugal machine until the fat is brought to 
 the center. It is then read off volumetrically. The 
 lactocrite gives a very close determination of the 
 fat in milk, but it is necessary to have a separator 
 frame in which to whirl the apparatus, which makes 
 it somewhat expensive. 
 
46 Milk and Its Products. 
 
 Fjord's control apparatus. — This apparatus, in- 
 vented by the late Professor Fjord, of Denmark, 
 estimates the fat by measuring the solidified cream. 
 Glass tubes similar to those used in the oil -test 
 churn are secured in a frame and a measured quan- 
 tity of milk put in each. The frame holding the 
 bottles is then whirled in a centrifugal separator 
 frame till the cream is completely separated and 
 brought together in a compact mass. This re- 
 quires about forty -five minutes. The solid mass 
 of cream is then measured with a scale and the 
 fat estimated from it by means of a table con- 
 structed by the inventor. This apparatus is in 
 very, common use in Denmark, but has never been 
 introduced into this country. 
 
 Development of milk tests in the United States. — Up 
 to the year 1888, there had been no apparatus devised 
 which would determine the fat in milk accurately, 
 easily, cheaply and quickly. None of the methods 
 described could in any sense supply the place of the 
 gravimetric analysis, even for commercial purposes. 
 The oil -test churn came the nearest to it, but that 
 was of no use for milk, and at this time the separa- 
 tor creamery was beginning to supplant the gathered- 
 cream factory, and the demand was constantly 
 stronger for a means of determining the fat in milk. 
 This year also marked the establishment of the na- 
 tional grant to Agricultural Experiment Stations in 
 each of the states, and one of the first problems at- 
 tacked by the chemists of these stations was to de- 
 vise a quick method for the determination of fat in 
 
American Tests. 47 
 
 milk. In the next two years no less than seven dis- 
 tinct methods were devised by chemists of Agricul- 
 tural Experiment Stations for this purpose. All of 
 them were much better than any that had hitherto 
 been known, but one was so much in advance of 
 any of the others that now it is practically the only 
 method used for the quick determination of fat in 
 milk. This is the method devised by Dr. S. M. Bab- 
 cock, known as the Babcock test, and first published 
 in July, 1890. The various tests, in the order of 
 their publication, were as follows : 
 
 Short's method. — This method was invented by 
 F. G. Short, at that time chemist of the Wisconsin 
 Agricultural Experiment Station, and was first pub- 
 lished in Bulletin No. 16 of the Wisconsin Agricul- 
 tural Experiment Station for July, 1888. In brief, 
 the method consisted in converting the fat in the 
 milk into a soap by means of an alkali, and then dis- 
 solving the soap by an acid, setting free the fat. 
 The process was rendered complete by boiling for 
 several hours. The determination was made with a 
 measured quantity of milk in a glass test bottle with 
 a narrow graduated neck, into which the fat was 
 raised at the end of the process and read off volu- 
 metrically. Considerably difficulty was often ex- 
 perienced in getting a clear separation of the fat 
 from the contents of the tube. The long period of 
 boiling was also an important drawback to the 
 method. 
 
 The method of Failyer and Willard. — This method 
 was devised by Professors Failyer and Willard, of 
 
48 Milk and Its Products. 
 
 the Kansas Agricultural Experiment Station, and 
 was published in the report of that station for 1888. 
 In it the solids of milk were destroyed by hydro- 
 chloric acid and the fat partially separated by means 
 of heat. The fat was then dissolved in gasoline, and, 
 after evaporation of the gasoline, was measured in 
 a graduated portion of the tube in which the opera- 
 tion was performed. It gave a clearer reading of 
 the fat than Short's method, but required more deli- 
 cate manipulation, particularly in heating the acid 
 and milk together and in evaporating the gasoline. 
 The time required was considerably less than with 
 Short's method. 
 
 Parsons' method. — This method was devised by 
 Professor C. L. Parsons, of the New Hampshire Ag- 
 ricultural Experiment Station, and published in the 
 report of that station for 1888. This method made 
 use of caustic soap and a solution of soap and alcohol 
 to destroy the milk solids, after which the fat was 
 dissolved in gasoline. A measured quantity of the 
 gasoline solution of fat was then taken, the gaso- 
 line evaporated from it and the fat carefully dried. 
 The free fat was then measured in a scale, and by 
 means of a calculation, the percentage of fat deter- 
 mined. This method gave very good results in the 
 hands of several different operators. It, perhaps, 
 required a little more delicate manipulation than 
 some of the others, and it was considerably more 
 complicated than Short's method. 
 
 The Iowa Station test. — This test was invented by 
 Professor George E. Patrick, the chemist of the Iowa 
 
Babcoch Test. 49 
 
 Agricultural Experiment Station, and published in 
 Bulletin No. 8, February, 1890, of the Iowa Experi- 
 ment Station. In this test the solids of the milk 
 were destroyed by a mixture of acetic, sulphuric and 
 hydrochloric acids, and the fat brought to the sur- 
 face by boiling. The test was made in a flask with 
 a narrow graduated neck. A measured quantity of 
 milk ,was put in the flask, a sufficient amount of 
 the acids added, and the whole boiled for ten or fif- 
 teen minutes. The Iowa Station test was a great 
 improvement upon any that preceded it in point of 
 simplicity accura|y and length of time required. 
 
 Cochran's ^|^^^^This method was invented by 
 C. B. Cochran^^^^^B Pennsylvania State Board of 
 Health, and Y^^^^^m in the Journal of Analytical 
 Chemistry, Vol^^i|^page 381. In this method 
 the solids of the milk other than the fat were de- 
 stroyed by the use of a mixture of acetic and sul- 
 phuric acids, aided by boiling.^ When the milk 
 solids 'Were thus completely disintegrated, the fat was 
 brought to the surface by the aid of ether, and then 
 the whole mass further boiled until the ether was all 
 evaporated. The clear melted fat was then meas- 
 ured by transferring it to a vessel with a gradu- 
 ated neck. The Cochran method was simple in 
 details, but required rather delicate manipulation in 
 transferring the melted fat from one vessel to an- 
 other. It, however, gave very good results in a 
 comparatively short time. 
 
 The Babcock test. — This test was invented by 
 Dr. S. M. Babcock, chemist of the Wisconsin Agri- 
 
 ■ D 
 
50 Milk and Its Products. 
 
 cultural Experiment Station, and published in Bul- 
 letin No. 24, July, 1890. In point of simplicity, 
 accuracy, ease of manipulation and time required, 
 this test is so much better than any that have pre- 
 ceded or followed it that it is now practically the 
 only one in use. To destroy the solids other than 
 the fat. Dr. Babcock makes use of a single rea- 
 gent, commercial sulphuric acid, of a specific gravity 
 of 1.82, and to separate the fat from the remain- 
 ing contents of the test bottle centrifugal force is 
 used, hot water being added to bring the contents 
 of the flask up to the graduatednart. The test is 
 made in a small flask with a i]|^^^^raduated neck. 
 
 The Beimling test. — This I^^^^H^ testing milk 
 was devised by Messrs. Leffn^^^^^rBeam, and is 
 sometimes known under their m^B; though the ap- 
 paratus was patented by H. F. Beimling, and intro- 
 duced under his name. The Beimling test was in- 
 troduced in the year 1890, and was essentially like 
 the Babcock test, the exception being that instead 
 of a single reagent two were used, one ordinary 
 commercial sulphuric acid, as in the Babcock test, 
 and the other a mixture of amyl alcohol and com- 
 mercial hydrochloric acid. Largely because of the 
 greater inconvenience of using two reagents, the 
 Beimling test has fallen into disuse. 
 
 Tests introduced since the Babcock test. — Two or 
 three tests differing but slightly from the Babcock 
 have been introduced since. One of these is known 
 as Gerber's method, the invention of a German 
 chemist. The form of the testing bottles differs 
 
Babcock Test. 
 
 51 
 
 somewhat from that nsecl by Dr. Babeock ; less 
 whirling is required, and the same reagents are 
 used as in the ease of the Beimling. The DeLaval 
 
 Fig. 1 Hind reutiitut^il for B iTx o* k test. 
 
 Separator Company has also introduced an appara- 
 tus for testing milk which is known as the butyrom- 
 eter. In this test a single reagent, sul]3hurie acid, 
 is used to set free the fat. The form of the ap- 
 
52 Milk and Its Products. 
 
 paratus is different from the Babcock test, a much 
 higher speed of whirling is used, a smaller sample 
 of milk is taken, and the fat is read in a solid 
 instead of a liquid form. 
 
 DETAILS OF THE BABCOOK TEST. 
 
 The apparatus used in testing milk by the Bab- 
 cock method consists of a centrifugal machine, three 
 pieces of glassware and commercial sulphuric acid. 
 
 The centrifugal machine. — Many forms of centri- 
 fugal machines are in use, almost every manufacturer 
 having his own particular style. It is essential that 
 the centrifugal should be substantially made ; that it 
 should run smoothly and steadily, either loaded or 
 empty, and that it should be capable of developing a 
 speed of 900 revolutions per minute, with a wheel 
 20 inches in diameter. The centrifugals so made 
 may be driven either by hand or steam power. In 
 the hand-power machines, the motion is transmitted 
 both by belts and by friction cogs ; in the latter 
 case it is essential that care be taken to prevent 
 loss of motion through the friction cogs becoming 
 worn. 
 
 In the centrifugals driven by steam turbines, or 
 jets of steam delivered against the circumference of 
 the revolving wheel, it is much better that the 
 steam be applied at some little distance from the 
 revolving bottles, otherwise too great a degree of 
 heat may be developed in the machine. WoU has 
 shown* that, in those steam turbines in which 
 
 * Hoard's Dairyman, March 9, 1900 : vol. 31, p. 75, 
 
The Bahcocl' Test Glassware. 
 
 53 
 
 steam is introduced into the bottle chamber or 
 where the cover fits so tightly that no cold air 
 enters the chamber during the whirling ; the bottles 
 are ofUn heated to such a degree that the reading 
 is made too large because of the expansion of the 
 fat at the high temperature. The fat should be read 
 at a temperature of 110° F., 
 but up to 140° F. the expan- 
 sion is not sufficient to cause 
 material error. When, how- 
 ever, the temperature rises to 
 200° F. or thereabout as fre- 
 quently occurs under the con- 
 ditions named above, the error 
 due to the expan- 
 sion of the fat may 
 amount to .15 to 
 .3 per cent. In all 
 such cases the bot- 
 tles should be al- 
 lowed to cool to at 
 least 140° F. before 
 reading. Those cen- 
 trifugals are most 
 satisfactory in which provision is made for the bottles 
 to assume a perfectly horizontal position when in mo- 
 tion and a perfectly perpendicular one when at rest. 
 The glassware. — The glassware consists of a flask 
 or test bottle in which the determination is made, 
 a graduated pipette for measuring the milk, and a 
 short graduated glass cylinder for measuring the 
 
 Fig. 4. Steam turbine eentril'ugul lor 
 Babcoek test. (See opposite jiage.) 
 
54 
 
 3IiU- and Its Products. 
 
 acid. The most essential feature of the glassware 
 is that it should lie accurately graduated. This in • 
 general can lie secured Ijy always procuring the 
 glassware from a reliahlc manufacturer or dealer, 
 
 Fig. Ti. FovTiis of Babeock test bottles ; a, ordiiiai'y bottle for wbole 
 milk : b, bottle for skim milk, using double charge of milk 
 
 c, Ohlsson, or " B. & W." double-net-ked bottle for skim milk 
 
 d, e, liottles for testing cream ; /, bottle with detachatde ueck 
 g, A, detachable necks for butter and cream. 
 
 though suspected glassware may be tested with com- 
 paratively little difficulty. The neck of tlie ordinary 
 test bottle is graduated from to 10, each divi- 
 sion being subdivided into Ave parts. The gradua- 
 tion from to 10 will contain a volume of melted 
 
Testing Butter, Cheese and Gream. 55 
 
 milk fat equivalent to 10 per cent of the weight of 
 the milk taken. Bach subdivision of the scale, 
 therefore, represents .2 of 1 per cent,. The capa- 
 city of the graduated portion of the neck is two 
 cubic centimeters. The specific gravity of melted 
 milk fat at a temperature of 120° F. is assumed to 
 be .9. The two cubic centimeters will, therefore, 
 weigh 1.8 grams, and in order that the percentage 
 of fat read off shall be percentage by weight and 
 not by volume, 18 grams of milk must be taken. 
 But milk has an average specific gravity of 1.032, 
 therefore 18 grams of milk will be contained in 
 17.44 cubic centimeters. Two cubic centimeters of 
 melted milk fat is, therefore, 10 per cent by weight 
 of 17.44' cubic centimeters of average milk. It 
 has been found by trial that a pipette of the or- 
 dinary form graduated at 17.6 cubic centimeters 
 will deliver slightly less than 17.5 cubic centimeters 
 of milk. The graduation of the ordinary pipette 
 should, therefore, be 17.6 cubic centimeters. A 
 little less acid than milk is ordinarily required, and 
 the acid measure is graduated at 17.5 cubic centi- 
 meters, though the amount of acid actually used 
 may readily vary two or three cubic centimeters 
 either way from this point. 
 
 The fat in the various products of milk may 
 be as readily determined by means of this test as 
 fat in the milk itself, and for these determinations 
 various forms of special apparatus have been de- 
 vised. (Fig 5.) For testing cream, bottles with a 
 capacity greater than 10 per cent are in use. Of 
 
56 Milk and Its Products. 
 
 these there are two forms. In one there is a bulb 
 in the middle of the neck, and graduations above 
 and below. Ordinarily the lower graduations have a 
 capacity of 5 per cent, the bulb a capacity of 10 
 per cent, and the upper graduations a capacity of 
 10 per cent. The use of this form of bottle re- 
 quires that when the fat is read off the bulb should 
 always be completely full, and the upper and lower 
 surfaces of the fat rest on the upper and lower 
 graduations respectively. Another form of cream 
 test bottle has a neck much wider than that used 
 for ordinary milk testing. Bottles of this form have 
 a capacity up to 35 per cent, or even more. The 
 graduations are usually not closer than .5 of 1 per 
 cent. This form does away with the awkwardness 
 of the bulb in the center, but it is not possible 
 to read the column of fat to so small a fraction, 
 usually to not less than .5 of 1 per cent. For 
 testing cream, particularly cream that is rich in fat, 
 a special pipette is necessary. The specific gravity 
 of cream containing 25 per cent of fat or over is 
 nearly that of water, and in testing cream of this 
 quality a pipette of 18 instead of 17.6 cubic cen- 
 timeters capacity is used. For testing skim -milk, 
 where it is desirable to read the small fractions of 
 1 per cent, two forms of bottles have been devised. 
 In one, two pipettes full of milk are used, and the 
 graduations have one -half the ordinary value ; in the 
 other form, the bottle has two necks, one of ordi- 
 nary width for the introduction of the milk and acid, 
 and the other an extremely narrow one, in which 
 
, Calibrating the Glassware. 57 
 
 the fat is measured. With this last it is possible 
 to fead easily to .05 of 1 per cent. 
 
 The fat in the solid milk products, as butter and 
 cheese, may also be conveniently determined by the 
 Babcock test. Since butter or cheese cannot be 
 measured, it is necessary that the sample to be 
 tested be weighed. Balances sensitive to .1 of a 
 gram are sufficiently delicate. Either 18 grams of 
 the substance may be weighed, in which case the 
 percentage of fat is read directly from the bottle ; 
 or, what is more convenient, any amount from 4 to 
 8 grams may be taken. In the latter case, the 
 observed reading of fat bears the same proportion 
 to the percentage of fat in the substance taken that 
 the weight of the sample taken bears to 18 ; and the 
 percentage is found by multiplying the observed read- 
 ing by 18 and dividing the result by the weight of 
 the sample taken. 
 
 In testing butter and cheese, it is convenient to 
 use the bottles with detachable necks. A little 
 water should be' added to the bottle before the 
 acid is put in, to aid in the solution of cheese. 
 
 Calibration of glassware. — The correctness of the 
 graduation of the glassware may be tested with more 
 or less accuracy according to the means at hand. 
 The bottles are all graduated on the assumption 
 that the tubes are of uniform caliber. The and 
 10 points are determined experimentally, and the in- 
 tervening space equally divided into 50 divisions 
 with a dividing engine. The spaces should, there- 
 fore, be of uniform size, and if the eye can detect 
 
58 Milk and Its Products. 
 
 any variation in the size of the spaces such bottles 
 should be discarded. Bottles inaccurate in this 
 respect are seldom met with now. When the test, 
 was first introduced they were of frequent occur- 
 rence. Bottles may be readily tested with a pipette 
 of 2 c. c* capacity. Fill the bottle carefully with 
 water to the point, wipe out the neck carefully, 
 and drop in exactly 2 c. c. of water. It should 
 just fill the neck to the top of the graduation. 
 If delicate balances are at hand, the bottle may be 
 weighed full of distilled or clean rain water to the 
 point, and then again filled to the 10 point. 
 The difference in weight should be exactly 2 grams. 
 The calibration will be still more accurate if mer- 
 cury instead of water is used ; 2 c. c. of mercury 
 may be measured out, or, what is still better, 
 weighed. The specific gravity of mercury is 13.59 ; 
 two c. c. will, therefore, weigh 27.18 grams. This 
 weighed or measured quantity of mercury is intro- 
 duced into a dry bottle, a close-fitting plug is then 
 inserted into the neck of the bottle exactly to the 
 top of the graduation, the bottle is then inverted ; 
 the mercury should exactly fill the graduated space. 
 The same portion of mercury can then be used to 
 test another bottle, and with care to have the 
 bottles dry, and to see that all of the mercury is 
 transferred each time, a large number of bottles can 
 be easily and quickly calibrated. 
 
 The pipettes are best tested by weighing a 
 pipette full of either water or mercury ; the former 
 
 * Cubic centimeter. See metric system, in Appendix. 
 
Precautions in Sampling Milk. 59 
 
 should weigh 17.6 grams, the latter 239 grams. 
 Any bottle or pipette that varies more than 2 per 
 cent from the standard should be discarded. 
 
 Sampling the milk. — The accuracy of the test 
 depends wholly upon getting an accurate sample of 
 the milk to be analyzed. A part of the fat so 
 readily separates from the milk in the form of 
 cream that milk cannot stand even for a short 
 time without the upper layer becoming richer and 
 the lower layers poorer in fat. Even in milk 
 freshly drawn from the cow, that in the upper part 
 of the pail will be considerably richer than that 
 below. The first step, then, in sampling milk is 
 that it should be evenly and thoroughly mixed. 
 This is best brought about by pouring from one 
 vessel to another • but if the milk has stood over 
 night and a layer of tough cream formed, the par- 
 ticles of cream will not be thoroughly mixed by a 
 single pouring from one vessel to another. In 
 all such cases, the sampling must not be done 
 until all visible portions of cream have disappeared 
 in the mass of the milk. Various forms of sam- 
 pling tubes or "milk thieves" have been devised for 
 taking samples of milk. They serve the purpose 
 fairly well, but are not to be depended upon in 
 comparison with a thorough agitation of the milk. 
 
 Where the previous night's milk is carried to the 
 factory, the agitation enroute and the stirring inci- 
 dent to pouring from the carrying can into the 
 weigh can are ordinarily sufficient to cause a pretty 
 complete mixture of the milk : but in cold weather 
 
60 Milk and Its Products. 
 
 it will frequently be noticed that the cream is not 
 thoroughly broken up. Under such conditions, extra 
 precautions must be taken to secure perfect sam- 
 pling. 
 
 Composite sampling. — In testing milk at factories, 
 it is more convenient to take a sample every day, 
 and make one test of the mixed samples at the end 
 of a week, ten days or two weeks. In order to do 
 this, it is necessary to provide a suitable receptacle 
 for the milk of each patron. ( Pint lightning -top 
 fruit jars or milk bottles, or glass -stoppered sample 
 bottles, are most convenient. ) To these bottles is 
 added each day a small portion of each patron's 
 milk, together with some preservative for preventing 
 the milk from souring. The preservatives in com- 
 mon use are bichromate of potash, corrosive subli- 
 mate, and milk preservaline. Caustic potash and 
 soda may also be used. Neumann* claims to have 
 had as good results with sodium nitrate as with 
 bichromate of potash. Most of these substances are 
 poisons, and render the milk unfit for use ; the jar 
 should, therefore, be plainly labeled. For many 
 reasons the bichromate of potash is to be preferred. 
 It gives a distinct color to the milk, and only a 
 small quantity of it is necessary to prevent the milk 
 from souring. Whatever preservative is employed 
 should only be used in quantity sufficient to keep 
 the milk from thickening. Of the bichromate of 
 potash, an amount sufficient to color the milk a bright 
 lemon yellow is all that is necessary. In taking 
 
 * Milch Zeitung, vol. xxii. p. 526. 
 
Measuring the Milk. 61 
 
 composite samples, an amount proportionate to the 
 amount of milk delivered should be taken each day. 
 This is conveniently done by the use of the Scovell 
 Aliquot Milk Sampler, which, besides serving this 
 purpose, gives the advantages of a milk thief in that 
 it takes milk from all parts of the vessel. Where 
 the milk varies only a few pounds from day to 
 day, good results may be obtained by taking a uni- 
 form amount of milk for the sample each day, but 
 where the variation in quantity is considerable, 
 aliquot samplers are much to be preferred. 
 
 Making the test. — In preparing to make the test, 
 the same care must be used that the sample shall 
 be thoroughly mixed and perfectly uniform, that 
 was taken in mixing the milk when the sample 
 was drawn. In measuring the milk, the pipette 
 should either be perfectly dry, or rinsed out with 
 the milk to be tested immediately before measur- 
 ing the assay. Where a large number of samples 
 are to be tested, the latter is found to be the better 
 practice. The greatest care should be taken that the 
 milk is accurately measured. The lower end of 
 the pipette should be placed about midway of the 
 sample of milk and the pipette filled by gentle 
 suction at the upper end. The milk should be 
 drawn into the tube above the mark on the neck, 
 and the end of the forefinger quickly placed over 
 the end of the pipette, the pipette being steadied 
 by the thumb and second and third fingers ; hold- 
 ing it now on a level with the eye between the eye 
 and the light, the pressure on the forefinger 
 
62 Milk and Its Products. 
 
 should be gradually relaxed and the milk allowed 
 to flow out of the lower end drop by drop until 
 the upper edge of the milk rests exactly upon the 
 graduated mark on the side of the pipette. The 
 milk is then transferred to the test bottle, and this 
 should always be done by placing the end of the 
 pipette against the side of the neck of the bottle, 
 relaxing the pressure of the forefinger gently at 
 first, allowing the milk to flow down the side of 
 the neck. If this is not done there is danger that 
 the neck will become clogged, and a part of the 
 milk be blown out by the escaping air. When 
 all of the milk has flowed from the pipette, the last 
 few drops should be gently blown into the neck of 
 the test bottle. The utmost care must be taken 
 that all of the milk is transferred from the pipette 
 to the test bottle, and none allowed to escape. 
 
 The acid. — The next step is the addition of the 
 acid. The acid should be put into the test bottle in 
 such a way that it will rinse down any milk that 
 has adhered to the sides of the neck, and pass be- 
 tween the milk and the glass in reaching the bot- 
 tom of the bottle. As soon as the acid is added, 
 the milk and acid should be shaken together with a 
 gentle rotary motion until all of the curd is com- 
 pletely dissolved, care being taken that no particles 
 of curd are thrown into the neck of the bottle. 
 The amount of acid used should be about the same 
 in volume as the milk, depending somewhat upon 
 its strength. Ordinary commercial sulphuric acid 
 with a specific gravity of 1.82 will require about 
 
Finishing the Test. 63 
 
 17.5 cubic centimeters to completely dissolve 17.6 
 cubic centimeters of milk. If the acid is too weak 
 the curd will not be completely dissolved, and will 
 appear as a curdy, flocculent precipitate mixed with 
 the lower part of the column of fat. If the acid 
 is too strong, some of the solids of the milk will 
 be charred, and will appear as dark -colored, floc- 
 culent particles, either mixed with the fat or im- 
 mediately under them, when the test is completed. 
 Slight differences in the strength of the acid may be 
 overcome by adding a little more or a little less, ac- 
 cording as it is too weak or too strong, but satis- 
 factory results cannot be depended upon unless the 
 acid is of the right strength; viz., 1.82 sp. gr. 
 Convenient hydrometers , may be secured for a tri- 
 fling amount, so that any one may be certain of the 
 strength of his acid. The sulphuric acid should 
 be kept tightly corked in a glass -stoppered bottle, 
 because when exposed to the air, it takes up water 
 rapidly, and soon becomes too weak. While it is 
 not necessary that the sulphuric acid should be chemi- 
 cally pure, some of the cheaper grades of commer- 
 cial acid often contain impurities that seriously 
 affect the results, causing black specks to appear in 
 the neck of the bottle. A reasonably pure commer- 
 cial acid should always be used, and can be secured 
 at a trifling cost above the impurer forms. 
 
 Whirling. — When the acid has been added and 
 thoroughly mixed with all of the samples, they are 
 put into the centrifugal machine and whirled steadily 
 for five minutes. At the end of this time the ma- 
 
64 Milk and Its Products. 
 
 chine is stopped, and the bottles are filled with 
 warm water to the bottom of the neck. They are 
 then whirled a second time for two minutes, when 
 water is again added up to about the 8 per cent 
 mark on the neck of the bottle, after 
 which they are given a whirl for one min- 
 ute. The bottles are then taken out and 
 -cread as rapidly as possible. 
 
 Beading. — The reading should be taken 
 at a temperature between 110° and 140° 
 F., at which temperatures the fat will be 
 completely fluid. The test should be made 
 in a room at a temperature not less than 
 70 F., or if the room is much colder 
 some means should be taken to prevent 
 the bottles from becoming cool until all are 
 read. Much skill and facility can be 
 attained by practice in reading the bottles 
 rapidly and accurately. In reading the 
 bottles, the reading should be made as 
 shown in the diagram, the lower reading 
 Fig. c. Dia- from the extreme lower curved surface 
 
 gram of neck /tt/i\ 
 
 of Baboock (a, Fig. 6), and the upper reading from 
 
 test bottle ; 
 
 the reading the extreme top or the column of fat, 
 
 should he, . t/v» 
 
 made be- (b , uot c, Fig. 6), the difference between 
 
 tween the 
 
 points a-b, the lower and upper reading giving the 
 
 not a-c. CT o o 
 
 percentage of fat. The reason for read- 
 ing in this way is that a small amount of residual 
 fat is left mixed with the other fluids in the bottle. 
 This is composed of the smaller globules of fat, and 
 the amount is practically uniform, and has been 
 
Estimation of Solids not Fat. 65 
 
 found to represent about the amount occupied by 
 the curved surfaces in the neck of the bottle, 
 due to the capillary attraction between the fat and 
 the glass. 
 
 Gleaning the glassware. — Good results cannot be 
 secured unless the glassware is kept clean and 
 bright. This can easily be done with very little 
 trouble. As soon as the bottles are read, and while 
 they are still hot, the contents should be emptied 
 out. The hot acid and water will carry out with 
 it the larger part of the fat in the neck of the 
 bottle. The emptied bottle should then be rinsed 
 once in warm water and once in hot water containing 
 some alkali, either washing soda or any of the va- 
 rious washing powders, and then rinsed with either 
 warm or cold water until they are perfectly clean. 
 With these precautions no difllculty will be expe- 
 rienced in keeping the bottles clean and bright. 
 
 By the use of the lactometer in connection with 
 the percentage of fat, a close approximation to the 
 percentage of total solids, or solids not fat, may be 
 made. Numerous formulae for this purpose have 
 been devised. Their application is explained and il- 
 lustrated in Part A of the Appendix. 
 
CHAPTER IV. 
 
 THE FERMENTS AND FERMENTATIONS OF MILK. 
 AND TEEIR CONTROL. 
 
 Milk, when it is first drawn, is a limpid fluid 
 with a slight odor, mildly sweetish taste, and faint 
 alkaline reaction. In fact, milk often shows the 
 amphoteric reaction ; that is, it will give the acid 
 reaction with blue litmus paper and the alkaline 
 reaction with red. Almost immediately after it is 
 drawn, milk begins to undergo a change, and within 
 a short time will show a distinct acid reaction. 
 The degree of acidity increases with the age of the 
 milk. Soon changes begin in the other milk con- 
 stituents, and in a comparatively short time, the de- 
 composition is so great that the milk can no longer 
 be used for food. The sugar is the first constit- 
 uent of the milk to undergo change, afterwards 
 the albuminoids are attacked, and lastly the fats. 
 These changes are not due to any instability of the 
 organic compounds in the milk, but to the effect 
 of various vegetable germs that gain access to the 
 milk after it is secreted, and, living and growing 
 in the milk, bring about the changes mentioned. 
 These changes are called fermentations, and the 
 agents that bring them about ferments. Milk con- 
 taining no germs of fermentation, or milk from 
 
 (66J 
 
General Characters of Bacteria. 67 
 
 which they have all been removed, is said to be 
 sterile. The germs found in milk belong to the 
 lowest orders of the vegetable kingdom. Most of 
 them are included in the bacteria, although many 
 yeasts and moulds are frequently found in milk. 
 
 The bacteria. — The bacteria are extremely minute 
 bodies consisting of a single cell filled with protoplasm. 
 They are of three general forms, — spherical (coccus); 
 rod -like or cylindrical (bacillus), and curved or wavy 
 (spirillum). They reproduce by fission; that is, the 
 cell elongates slightly in the direction of its longer 
 axis, and a partition is formed across the cell trans- 
 versely, and two individuals exist where there was 
 but one before. These may break away and form 
 separate bacteria, but often they are kept together 
 in various ways. Many forms are endowed with 
 motion, and all require a liquid or semi -liquid me- 
 dium for growth and development, though many 
 may exist for long periods of time in a dry condi- 
 tion. Like other plants, in order to grow and de- 
 velop, the bacteria must have suitable food. They 
 require for their sustenance carbon, hydrogen, oxy- 
 gen and nitrogen, together with small amounts 
 of mineral matters. Organic compounds are more 
 available for food supply than simple inorganic 
 salts. Substances like sugar and the various al- 
 buminous compounds are admirably suited for their 
 food. In ordinary milk nearly all kinds of bacteria 
 find an adequate and easily available food supply 
 in a medium favorable to ,their growth, so that not 
 only the forms of bacteria ordinarily found in milk, 
 
68 Milk and Its Products. 
 
 but almost any others, will readily live and grow 
 should they gain access to milk. Nearly all forms 
 of bacteria are sensitive to conditions of tempera- 
 ture. The range of temperature in which they 
 thrive the best and grow most rapidly is rather 
 narrow, though there is a considerable range above 
 or below, in which they will still grow and develop. 
 The temperature at which any given germ will grow 
 most rapidly is called the optimum temperature, and 
 the optimum temperature varies widely with the 
 various classes of organisms, though by far the 
 larger number of bacteria find their optimum point 
 between 75° to 100° F., and a higher temperature 
 not only stops their growth, but if sufficiently high 
 kills them outright. A temperature of 135° F. kills a 
 large number of germs. Very few are able to live 
 above a temperature of 180°, and none can with- 
 stand the temperature of boiling water, 212°, for 
 more than a few minutes. If heat is accompanied 
 by moisture it is much more effective, so that heat 
 applied in the form of live steam is the best means 
 of destroying the life of these germs. Under the 
 influence of cold the germs become inactive, and 
 some kinds are killed by a sufficient degree of cold, 
 but very many kinds are able to withstand any 
 degree of cold possible to be produced for long pe- 
 riods of time. 
 
 Under certain conditions bacteria are able to as- 
 sume an inactive condition, or spore form. In do- 
 ing this, the protoplasm shrinks into a hard, glisten- 
 ing mass, and contracts toward one end of the cell. 
 
Distribution of Bacteria. 69 
 
 or the wall cell thickens and encloses the proto- 
 plasm. In the spore condition the bacteria are in- 
 active, but are able to endure much greater extremes 
 of heat, cold or moisture than when active. When 
 the conditions of growth become again favorable, the 
 spore again becomes active, or is said to germinate, 
 and the vital processes are resumed. 
 
 Bacteria are widely distributed through nature. 
 In fact, there are very few places where they may 
 not be found. They are so light and small that 
 they float readily in the atmosphere, particularly when 
 accompanied by particles of dust. They are found 
 in all rivers and streams, upon the surface of the 
 earth, and upon all organic matter. In fact, they 
 are universally distributed. By far the larger num- 
 ber are not only perfectly harmless biit positively 
 beneficial. They serve to transform dead organic 
 matter into its original condition, and so act as 
 scavengers. Others, like the milk ferments, bring 
 about specific changes in some definite substances, 
 while still others, a large class, are the specific 
 causes of various diseases in men and animals. 
 
 Presence of bacteria in milJc. — In ordinary milk, 
 bacteria are always present in large numbers. These 
 gain access to the milk from the atmosphere, from 
 the bodies of the animal and the milker, through 
 contact with the vessels into which the milk is 
 drawn, and to some extent through the udder of the 
 animal. The milk when secreted- is sterile. So 
 far as is known, no bacteria can pass through the 
 digestive organs and blood vessels of the animal 
 
70 Milk and Its Products. 
 
 and appear in the milk. If the udder is the seat 
 of disease due to the growth of bacteria, such bac- 
 teria may find their way into the milk ducts and 
 infect the milk. In one other way the animal may 
 be said to be a source of infection with bacteria. 
 The end of the teat of the animal is always more 
 or less moist. Bacteria coming in contact with 
 such surface, moistened with milk, find there not 
 only food in proper form for their growth, but a 
 temperature sufficient to make them active. They 
 begin to multiply, and, workipg their way through 
 the orifice of the teat, find milk in larger supply, and 
 a temperature still more favorable for their growth. 
 They increase and multiply, under such conditions, 
 with remarkable rapidity, and so work their way 
 upward through the milk cistern and into the larger 
 milk ducts, so that the milk first drawn from the 
 animal always contains a greater or less number of 
 bacteria. For this reason it is not an easy matter 
 to secure perfectly sterile milk direct from the cow, 
 though with great care in disinfecting the udder 
 and removing the larger part of the milk from it, 
 perfectly sterile milk has been obtained. 
 
 Kinds of bacteria in milk. — Almost any of the 
 known forms of bacteria may live and grow and oc- 
 casionally be found in milk. Normally, however, com- 
 paratively few forms of bacteria are present. The 
 greater part of these are forms which cause various 
 changes in the constituents of milk, and are known 
 as ferments, and the changes which they induce as 
 fermentations. Beside these fermentations, there may 
 
Kinds of Milk Fermentations. 71 
 
 be found in the milk the bacteria of any germ dis- 
 ease with which the animal may be aflicted, or which 
 may be carried into the milk through the atmosphere, 
 the water used in cleansing utensils, or the persons 
 of individuals suffering from the disease. 
 
 The fermentations of milk. — The normal fermenta- 
 tions to which milk is subject may be conveniently 
 divided into three classes. First, those which feed 
 upon and cause changes in the milk-sugar, known as 
 lactic fermentations. Second, those that feed upon 
 and cause changes in the albuminoids of the milk ; 
 these in turn are of two classes, peptogenic and pu- 
 trefactive. Third, those which attack the fats, and 
 are known as butyric fermentations. Besides these, 
 which may be called normal fermentations, in that 
 they will easily occur in any sample of milk if left to 
 itself, there are a large number of other fermentations 
 which may be called abnormal, from the fact that 
 they occur only in isolated localities, or from time 
 to time. These abnormal fermentations include one 
 which causes the casein of milk to coagulate without 
 the development of lactic acid, known as sweet curd- 
 ling ; another, which causes a peculiarly ropy or slimy 
 condition of certain constituents of milk ; still an- 
 other that results in the formation of an intensely 
 bitter product in the milk ; an alcoholic fermenta- 
 tion, and several fermentations which result in the 
 production of various colors, collectively known as 
 chromogenic fermentations. An illustration of this 
 class is seen in the well-known "bloody bread," 
 which is caused by the growth of Bacillus prodigiosus. 
 
72 MilJc and Its Products. 
 
 This germ is occasionally found in milk, and imparts 
 to it a red color which is easily confounded with 
 the red color due to the presence of blood from a 
 wounded udder. A single germ rarely occasions 
 more than a single fermentation. Often two or more 
 are combined in the fermentation, and in many cases 
 there are a large number of different germs that 
 bring about the same fermentation. This is notably 
 true of the lactic and putrefactive fermentations. 
 The effect of the various fermentations is such as to 
 destroy the value of the milk as such, if they are al- 
 lowed to proceed to any great length ; but the manu- 
 facture of butter is greatly aided by many of these 
 fermentations, and the presence of certain germs is 
 absolutely indispensable to the manufacture of cheese. 
 Relation of milk bacteria to the human system. — By 
 far the greater number of germs ordinarily found in 
 milk are absolutely harmless, and may be taken into 
 the human system in large numbers with perfect 
 impunity, the germs of specific disease excepted, and 
 with these latter it is the products formed from their 
 growth rather than the germs themselves from which 
 danger comes. There are probably no germs normally 
 found in milk that may be classed as harmful. This 
 is also true of a considerable number of fermen- 
 tation products resulting from the growth of the 
 germs in the milk. Many of these products give 
 to the mUk or its product an unpleasant taste or 
 physical appearance, but are otherwise perfectly 
 harmless. There are, however, certain germs which 
 produce a fermentation which results in the forma- 
 
The Lactic Acid Germ. 73 
 
 tion of poisonous products. These products are the 
 causes of the serious or even fatal results that fol- 
 low the consumption of milk, cheese, ice-cream, or 
 other products containing them. They are collect- 
 ively known as ptomaines. To one in particular, 
 that has frequently been found in cheese, the name 
 tyrotoxicon (cheese -poison) has been given. They 
 have been studied by Vaughn* and others, but 
 their origin is still obscure. The germs producing 
 these poisonous products are of comparatively in- 
 frequent occurrence. 
 
 In general, the various classes of fermentations do 
 not readily take place at the, same time. The active 
 growth and development of one germ acts more or 
 less as a retarding force upon the growth and de- 
 velopment of other germs. 
 
 Lactic fermentations. — Under this group we include 
 all of those germs which, living and growing in 
 milk, feed upon the sugar, causing it to change to 
 lactic acid. It was formerly supposed that the forma- 
 tion of lactic acid in the milk was entirely due to the 
 action of a single germ, described by Hueppe, and 
 called Bacillus acidi-lactici, or the lactic acid germ. 
 It is now known that there are at least twenty different 
 germs that may produce lactic acid, and in all prob- 
 ability there are many more. The lactic acid germs 
 are the most common and most numerous germs 
 found in milk, and ordinarily the lactic fermentations 
 are the first to take place. They begin their opera- 
 
 * Vaughn-Novy. Ptomaines and lieucomaines, Philadelphia, 1896. 
 
74 Milk and Its Products. 
 
 tions almost immediately after the milk is drawn, and 
 continue until the maximum amount of lactic acid has 
 been produced. In the lactic acid fermentations one 
 molecule of milk-sugar (C12H22OH + H2O) breaks up 
 into four molecules of lactic acid (C3H6O3) without 
 the formation of any secondary or by-product. The 
 presence of the lactic acid serves to coagulate the 
 casein, so that curdling of the milk is always an 
 accompaniment of the lactic fermentation after it 
 has reached a certain stage. The presence of lactic 
 acid is unfavorable to the growth of the ordinary 
 germs of lactic fermentation, and when a certain 
 amount of lactic acid has been formed (about .8 of 1 
 per cent of the whole milk), the further develop- 
 ment of lactic acid ceases. In milk of ordinary 
 quality, this occurs when about one -fourth of the 
 milk-sugar has been changed to lactic acid. If the 
 acid be neutralized with an alkali, the fermentation 
 will then proceed until another portion of milk-sugar 
 has been changed to lactic acid, showing that the 
 lactic acid simply prevents the growth of the germs, 
 and does not kill them. Lactic acid germs are most 
 active at temperatures between 80° and 100° F.; at 
 temperatures below 80° they gradually lose their ac- 
 tivity, and below 50° little or no lactic acid will be 
 formed. At these low temperatures they are simply 
 inactive, not dead. At a temperature of 105° F., 
 the lactic germs become inactive, and a large propor- 
 tion of them are killed at a temperature from 135° 
 to 140° F. In milk, lactic acid fermentation means 
 simply souring, and it renders the milk unfit for use. 
 
Putrefactive Fermentations. 75 
 
 almost wholly because the taste is unpleasant to 
 the ordinary palate. A large amount of lactic acid 
 is, perhaps, injurious to young and delicate or weak 
 digestive organs, but ordinarily is harmless. Lactic 
 acid fermentations are extremely important in the 
 processes of both butter and cheese manufacture, 
 and their relations to these processes will be dis- 
 cussed in detail in the proper place. 
 
 Fermentations affecting the albuminoids. — These in- 
 clude ordinary putrefactive fermentations, peptogenie 
 fermentations, and fermentations resulting in the for- 
 mation of poisonous products. These fermentations, 
 as a rule, do not thrive in the presence of a strong 
 lactic fermentation, so that ordinarily they do not 
 manifest themselves in milk unless the conditions are 
 peculiarly favorable for their development and un- 
 favorable for the development of lactic acid. Many 
 of the putrefactive fermentations will go on at a 
 lower temperature than the lactic fermentations do ; 
 hence it is often found, when milk is kept at a low 
 temperature in order to keep it from souring, that 
 after a certain time it becomes bitter or foul -smell- 
 ing. This condition is caused by some one of the 
 characteristic putrefactive fermentations. The putre- 
 factive germs also readily take on the spore form, 
 and in this condition are not so readily killed by 
 heat. The putrefactive fermentations usually result 
 in the formation of bitter or other unpleasant flavors 
 and disagreeable odors, and they are frequently ac- 
 companied by a considerable evolution of gas. Pep- 
 togenie fermentations are those which exert a pep- 
 
76 Milk and Its Products. 
 
 tonizing or digestive action upon the albuminoids. 
 By their action the casein is first coagulated, and 
 finally liquefied or changed into a peptone. 
 
 Butyric fermentations. — The butyric ferments at- 
 tack the fats, and result in the formation of bu- 
 tyric acid. They produce the peculiar condition 
 found in cream and butter known as rancidity, and 
 do not usually manifest themselves very strongly in 
 the milk. 
 
 Control of Fermentations. 
 
 Since fermentations always occur in milk that is 
 kept for any considerable time, and since they exert 
 so powerful an influence, not only upon the milk 
 but upon the products manufactured from it, the 
 question of their control is one of prime importance. 
 The three chief means of such control are : First, 
 prevention of infection ; second, prevention of the 
 growth of germs already present ; third, destruction 
 of germs already present. 
 
 Prevention of infection. — The greatest source of 
 infection comes from the body of the animal and 
 from the air of the stable. The germs are always 
 present, adhering to the hair of the animal, and par- 
 ticularly to any particles of dust or dirt. In order, 
 then, that the animal shall not be a source of infec- 
 tion, it is necessary that she be carefully curried 
 and the udder, teats, flank, thighs and lower parts 
 of the belly wiped off with a damp cloth immediately 
 
Prevention of Infection. 77 
 
 before milking. It is of course necessary, also, that 
 the hands and clothes of the milker should be as 
 carefully attended to in this respect as is the body of 
 the cow. The bacteria find in the excrements abun- 
 dant food for growth and development, and are al- 
 ways found in large numbers where such excrements 
 are allowed to collect ; and when dirt of this sort ac- 
 cumulates and becomes dried, the dust floating in the 
 air always carries with it large numbers of germs. 
 The germs are also found in large numbers accom- 
 panying the dust arising from hay and other dried 
 forage. This being the case, it is essential not only 
 that the stable should be kept scrupulously clean, 
 but that the air should be free from dust, partic- 
 ularly at times when milking is going on. Thor- 
 oughly sweeping and then sprinkling the stable 
 floors an hour or two before the milking will mate- 
 rially lessen the germ content of the milk. 
 
 Next to the stable, the dairy utensils are an im- 
 portant source of infection with bacteria. They be- 
 come attached to the seams and corners of the ves- 
 sels, and are not dislodged even with the most careful 
 cleaning, and when the fresh, warm milk is drawn 
 into such vessels the germs immediately begin to grow 
 and develop. The most scrupulous care must, of 
 course, be taken in cleaning any vessels in which 
 milk is contained, but no vessel can be considered 
 safe so far as conveying germs is concerned unless 
 it has been exposed to the action of live steam for 
 at least three minutes, and then kept in a secure 
 place until needed for use. With these precautions 
 
78 Milk and Its Products. 
 
 in regard to the animal, milker and utensils, mUk 
 may be secured with a minimum number of bacteria. 
 The difference in the number of bacteria in milk so 
 drawn, and in milk carelessly drawn, may easily 
 amount to a difference of eighteen to twenty -foui- 
 hours in keeping quality under like conditions. 
 
 Holding at low temperatures. — If milk be immedi- 
 ately cooled to a temperature of 40° P., or thereabouts, 
 very little fermentation will go on, though it will be 
 frequently found that after three or four days the 
 milk or cream may have a more or less disagreeable 
 flavor, due to the presence of some germs that de- 
 velop slowly even at low temperatures. If low tem- 
 peratures are to be depended upon as a means of 
 keeping fermentations in check, it is, of course, of 
 prime importance that every precaution should have 
 been taken to prevent the access of germs to the 
 milk in the first place. The fewer germs the milk 
 contains to begin with, the more effective will low 
 temperatures be as a means of preservation. With 
 care in both these respects, milk or cream may be 
 kept in a fresh and merchantable condition for a 
 week or ten days. 
 
 Destruction of germs in the milk. — A large number 
 of chemical agents is more or less destructive to 
 germ life. Many of them are so' violent in their 
 action as to destroy the milk as well as the germs, 
 but there are many which are destructive to germ 
 life, with no effect upon the composition, odor or 
 flavor of the milk ; but all of these without excep- 
 tion are more or less injurious to the human sys- 
 
Antiseptics and Disinfectants. 79 
 
 tem, particularly if they are used continuously, even 
 though only in small quantities. Of the compounds 
 which may be used for this purpose, formalin, saly- 
 cilic and boracic acids and their derivatives are un- 
 doubtedly the least injurious, but their use is not 
 to be recommended under any circumstances. Some 
 attempts have been made to utilize the electric cur- 
 rent as a means of destroying germ life in milk ; 
 but they have so far proved ineffectual, and in- 
 stances are reported* where electrolysis of the milk 
 constituents occurred where a continuous current was 
 employed. Heat, then, is the only available agent 
 that can be used for the destruction of germs al- 
 ready present in the milk. This destruction of germs 
 in milk or any other fluid by means of heat is called 
 sterilization. In order to absolutely sterilize any sub- 
 stance, it is necessary that it should be subjected 
 to a heat of 212° to 240° P. for one hour on each 
 of three successive days. This will kill not only the 
 germs that are in active growing condition, but any 
 spores that may be present. A lower temperature, 
 175° to 212° F., will kill actively growing germs, but 
 even at this temperature chemical changes are set up 
 in the milk which give rise to flavors known as 
 boiled or cooked flavors, that are disagreeable to a 
 large number of people. In order to overcome the 
 bad effects of heating at such high temperatures 
 another process, known as pasteurization, is used. 
 Pasteurisation. — The name is taken from Pasteur, 
 
 *L'Industrie Laitiere, April 1896. 
 
80 Milk and Its Products. 
 
 who discovered and used the process in controlling 
 the fermentations of wine and beer. It differs from 
 sterilization only in the degree of heat used, and, in 
 fact, may be properly called an incomplete or partial 
 sterilization. The destructive effect of heat upon 
 germ life depends both upon the degree of heat and 
 the length of time to which the germs are exposed. 
 A large number of germs are killed at temperatures 
 from 133° to 140° F., while others are killed at tem- 
 peratures varying from 150° to 165° F. These latter 
 temperatures include the germs of all of the ordinary 
 ferments and most of the germs of specific diseases, 
 including that of the tubercle bacillus. Since the 
 tubercle bacillus is the disease germ most likely to be 
 present, milk is ordinarily considered to be safe from 
 disease germs when it has been pasteurized at a tem- 
 perature sufficiently high to destroy it. This is a 
 temperature of 149° F. for thirty minutes, a tem- 
 perature of 155° F. for fifteen minutes, or a tempera- 
 ture of 167° F. for ten minutes, and these temperatures 
 have come to be looked upon as standard pasteuriz- 
 ing temperatures. Milk may be heated to 165° F., 
 if quickly cooled afterwards, without developing a 
 boiled taste ; so that it is possible that milk be 
 rendered safe from the germs of disease and free 
 from the ordinary germs of fermentation without 
 developing in it a boiled taste. But in order to 
 pasteurize milk safely, it is necessary that means 
 should be provided for cooling rapidly from the 
 pasteurizing temperatures to 50° F. or below. 
 
 Milk carefully pasteurized, as above described, will 
 
Apparatus for Pasteurization. 81 
 
 remain sweet thirty -six to forty -eight hours longer 
 at ordinary temperatures than milk not pasteurized, 
 from which germs have been excluded with ordinary 
 care. 
 
 The problem of successful pasteurization, then, 
 depends upon the means of raising the milk in a 
 short time to the required temperature, holding it 
 there uniformly for ten or twenty minutes, and then 
 cooling it rapidly to 50° or below. Several forms 
 of apparatus have been devised for this purpose. 
 Some of them are fairly perfect, but most of them 
 are lacking in some important point. With the pres- 
 ent activity in regard to this subject we shall un- 
 doubtedly have in the course of a year or two, much 
 more perfect apparatuses for this purpose than are 
 at present available. The perfect pasteurizing ma- 
 chine should cover the following points : Quick, 
 perfect and uniform heating of the milk ; perfect 
 control of the temperature ; quick and uniform cool- 
 ing ; compact form ; ease of cleansing ; absence of 
 pumping arrangements ; security against re -infection 
 during the process. 
 
 Selection of milk for pasteurization. — For the best 
 results in pasteurizing, it is also essential that the 
 milk be as fresh and free from fermentations as 
 possible. Russel and Farrington have found* that 
 milk that has developed as much as .2 of 1 per 
 cent of lactic acid is too sour for satisfactory re- 
 sults. Inasmuch as this amount of acid cannot 
 
 •Wisconsin Agr. Exp. Station, Bulls. 44 and 52. 
 F 
 
82 Milk and Its Products. 
 
 readily be detected by the senses of smell or taste, 
 Farrington's alkaline tablets offer a very convenient 
 means of selecting milks that are suitable or un- 
 suitable for pasteurizing purposes. For this purpose 
 it is convenient to make the tablet solution (see 
 Chap. VII.) by dissolving one tablet in each ounce 
 of water, or one tablet in 30 c. c. of water. Then 
 with a cup or other convenient vessel and a small 
 measure of any suitable size, the comparative acid- 
 ity of different milks can be readily and quickly de- 
 termined ■ as follows : Put a measure full of milk 
 into the cup and add two measures of the tablet 
 solution. If the color disappears, more than .2 of 1 
 per cent of lactic acid is present, and the milk is too 
 sour for pasteurizing purposes. If the milk remains 
 pink, less than .2 of 1 per cent of lactic acid is pres- 
 ent, and the milk may be safely used. If it is 
 desirable to measure the amount of acid, each meas- 
 ure of solution may be roughly taken to represent 
 .1 of 1 per cent of acid. Thus, if the pink color 
 remains when one measure of the solution has been 
 added, the milk contains .1 per cent of acid. If it 
 require four measures of the solution before the pink 
 color is permanent, the milk contains .4 per cent of 
 acid. A convenient measure for this purpose is made 
 by soldering a piece of stiff wire to the side of a 
 No. 10 cartridge shell, after the manner of a milk- 
 measuring dipper. 
 
CHAPTER V. 
 
 MARKET MILK. 
 
 In general, any conditions which make milk 
 of better quality for manufacture, also make it of 
 better quality to be consumed as milk. These 
 conditions are not only those which have to do with 
 the composition of the milk, but any other influences, 
 as feed, health, care of the cows, or conditions of 
 cleanliness. Several conditions affect the quality of 
 milk intended for consumption as such. In the 
 first place, it must be of high quality so far as 
 the composition is concerned. Second, it must be 
 secreted from healthy cows, fed on pure food and 
 kept in clean stables. Third, it must be so treated 
 that the fat does not readily separate from the other 
 solids, and it must not readily undergo fermentation. 
 Last of all, it must be clean. 
 
 Cleanliness. — Since cleanliness is equally impor- 
 tant, whether the milk is intended for consumption 
 or manufacture, it is well to take this up in detail 
 first. All vessels used to contain milk should be 
 heavily tinned ; pails, cans, and the like, that are 
 of the kind called ironclad are preferable on ac- 
 count of durability. An efficient means of attain- 
 ing cleanliness is in avoiding seams in the utensils. 
 
 (83) 
 
84 Milk and Its Products. 
 
 This is secured by the use of the pressed or seam- 
 less vessels wherever possible, and when it is not 
 possible to use these, by taking care that the joints 
 are completely and smoothly filled with solder. In 
 ordinary pails as found in the market this is never 
 done, and it is a matter of considerable importance 
 to the purchaser that all such seams be resoldered 
 before using. The tinware should be kept bright 
 and perfect. So soon as any rust spots make their 
 appearance, an entrance is given into the soft iron 
 for germs and small particles of decaying matter, 
 which are in consequence removed with much more 
 difficulty. Milk is much more easily removed from 
 vessels when it has not been allowed to become 
 dried upon their surface. If rinsed as soon as 
 emptied, tin vessels may be much more easily cleaned 
 than if allowed to stand for several hours. For 
 such rinsing, lukewarm water is much preferable to 
 cold or hot water. Cold water does not so readily 
 unite with the milk as warm water, and hot water, 
 by coagulating the albumin, may cause the milk to 
 stick or "cook on" to the sides of the vessel. The 
 process of cleaning vessels that have contained milk 
 should be : First, to rinse them thoroughly in luke- 
 warm water ; second, to wash them thoroughly with 
 the aid of some good soap or alkali, in water as 
 hot as the hand will bear ; third, to thoroughly 
 rinse in hot water ; fourth, to expose to live 
 steam from one to two minutes ; fifth, exposure, if 
 possible, in bright sunlight from two to three hours. 
 With these precautions, not only will the tinware be 
 
Methods of Securing Clean Milk. 85 
 
 kept clean and bright, but no germs will find a 
 resting place in the crevices. The use of much 
 strong alkali is inadvisable, as it serves to cloud 
 and tarnish the tin, giving it a dull appearance. If 
 the vessels are exposed to steam until they are 
 thoroughly hot, and then placed in such position 
 that they will drain, no other drying will be neces- 
 sary. 
 
 Having taken every precaution that the vessels 
 are thoroughly cleansed, the prevention of access 
 of dirt to the milk in process of milking is impor- 
 tant. To this end, the body, especially the lower 
 part of the belly and udder, of the cow should be 
 thoroughly brushed and preferably dampened just 
 before milking. The hands of the milker should 
 be clean and his clothes free from dust, and the 
 air of the stable should be free from dust. If 
 the stable floor is dampened, it will not only aid 
 in this respect, but in summer time will materi- 
 ally reduce the temperature of hot and overcrowded 
 stables. With these precautions, we may expect to 
 secure milk containing a minimum amount of dirt ; 
 but with all these precautions, more or less dirt will 
 find access to it. And immediately after milk- 
 ing, as much as possible of this dirt should be 
 removed by at once straining the milk through a 
 brass wire strainer of not less than fifty meshes to 
 the inch and three or four thicknesses of loosely 
 woven cotton or woolen cloth. The cloth strainer 
 not only removes fine particles of dirt, but also 
 entangles a considerable number of germs, and hence 
 
86 
 
 Milk and Its Products. 
 
 these strainers should be cleansed with great care, 
 and should be frequently renewed. 
 
 Treatment after drawing. — So soon as the milk is 
 drawn, it should be rapidlj' brought to a temperature 
 slightly below the surrounding atmosphere. While it 
 is being cooled it should be stirred to prevent the 
 cream from rising, and in milk that has been cooled 
 in this way there will be comparatively little tendency 
 afterward for the cream to separate from the milk. 
 Milk so treated is in an ideal condition for consump- 
 tion, even though the consumer may consider the 
 quality poor because of the slight tendency of the 
 cream to form on the surface. 
 
 Aeration of milk. — -Milk when drawn from the cow 
 contains a certain amount of dissolved gases. These 
 
 gases contain more or less 
 of what is known as animal 
 odor, the amount of this 
 odor depending very largely 
 upon the physical condition 
 of the animal at the time 
 the milk is drawn. Some- 
 times the amount is very 
 slight and scarcely notice- 
 able, at other times it is so 
 great as to be extremely of- 
 fensive. These gases and 
 the accompanying odor are 
 easily removed from the 
 
 Fig. 7 Star" milk cooler and 
 
 aerator. milk by cxposurc of the 
 
Oood Influence of Aeration. 
 
 87 
 
 milk to the air during the process of cooling, and to 
 this extent aeration of the milk is ' an advantage. 
 Various forms of aerators and combined aerators and 
 coolers have been devised, many of which are simple 
 and effective, and the best results follow their use. 
 In order to secure these results by 
 aeration, however, it is necessary 
 that the apparatus used for aeration 
 should expose the milk thoroughly 
 to the air, should not be cumber- 
 some, and should be simple and ea- 
 sily cleaned; moreover, the process 
 of aeration should always take place 
 in the purest atmosphere possible. 
 
 Delivery of the milk. — In ordi- 
 nary practice in the smaller towns 
 and villages, and to a considerable 
 extent in the larger cities also, the 
 milk is placed in cans in which it is transported 
 from the dairy, and is measured out in small quan- 
 tities to each customer from the cans in which it was 
 originally placed. Where care is taken to cool the 
 milk, as described, and during the process of serving 
 the customers to keep the contents of the cans well 
 stirred, substantial justice is done each individual cus- 
 tomer in the matter of giving him the due proportion 
 of cream and skimmed milk. This has been well 
 shown in a trial made at the Cornell University 
 Agricultural Experiment Station* several years ago, 
 
 Pig. 8. "Champion" 
 milk cooler and aera- 
 tor. 
 
 ♦Cornell University Agricultural Experiment Station, Bulletin No. 20. 
 
88 Milk and Its Products. 
 
 the interesting results of which are quoted below in 
 full detail : 
 
 To determine just how much variation there is in the fat 
 of milk served to the different patrons of a route by dipping, 
 a member of the Station staff accompanied a, milkman as he 
 went upon his route, and as the milk was about to be 
 served to various patrons, took samples for analysis. The 
 dipper, such as is ordinarily used by milkmen, was provided 
 with a long handle, so that it rested on the bottom of the 
 can when not in use. The milk was not stirred except by the 
 motion of the wagon and the raising of the dipper. Twelve 
 samples were taken, and yielded to analysis the following per- 
 centages of fat -. 
 
 No. 
 
 1 
 
 . 4.52) 
 
 2 . 
 
 4.43 [ 
 
 3 
 
 4.41 j 
 
 4 
 
 4.32) 
 
 5 . 
 
 . 3.85 y 
 
 6 . 
 
 . . 5.05 j 
 
 7 
 
 4.15) 
 
 8 . 
 
 4.02 \ 
 
 9 
 
 4.05 j 
 
 10 . 
 
 . . 4.94) 
 
 11 
 
 4.78 [ 
 
 12 . 
 
 4.85 J 
 
 Taken from Can A. 
 
 Taken from Can B. 
 
 Taken from Can C. 
 
 Taken from Can D. 
 
 The milk was contained in four 30-quart cans, marked 
 A, B, C and D. The samples were taken as follows: 
 
 No. 1. — Taken from A at 5.50 a. m. , within a few rods 
 of starting. 
 
 No. 2. — Taken when the milk in A was half gone, at 
 6.10. Seventeen dips had been made since No. 1 was taken, 
 and three-fourths of a mile traveled. 
 
 No. 3. — Taken from the bottom of A at 6.20. Twelve dips 
 had been made since No. 2 was taken, and three-fourths of a 
 mile traveled. 
 
 No. 4. — Taken from the top of B at 6.10, three-fourths of 
 a mile from starting. 
 
Variations in Quality in Dipping from Cans. 89 
 
 No. 5.— Taken from the middle of B at 7.20. Six quarts 
 had been added to B at 6.35, and two and one-fourth miles 
 traveled between taking samples 4 and 5. 
 
 No. 6. — Taken from the bottom of B at 7.55. One and 
 three-quarter miles traveled since taking sample 5. 
 
 No. 7. —Taken from the top of C at 6.20, one and one- 
 half miles from the start. 
 
 No. 8. — Taken from the middle of C at 6.50. One mile 
 had been traveled since taking No. 7. At 6.35 six quarts re- 
 maining in the bottom of A, and about an equal quantity 
 bought of another dealer, had been added to G. 
 
 No. 9. — Taken from the bottom of C at 7.00. Fifteen 
 dips had been made, and a half mile traveled, since 8 was 
 taken. 
 
 No. 10. — Taken from the top of D at 7.50. 
 
 No. 11. — Taken from the middle of D at a time when 
 the wagon had stood still for four minutes, with the dipper 
 resting on the botton of the can. Time, 8.15, and one mile 
 traveled since 10 was taken. 
 
 No. 12. — Taken from the bottom of D. 
 
 A second and third trial gave similar results. 
 
 
 • . 
 
 3E00ND 
 
 TRIAL. 
 
 
 
 a. 
 
 b. 
 
 Average. 
 
 
 Sample 1 . 
 
 . 4.86 
 
 4.78 
 
 4,82 
 
 (Before starting.) 
 
 Sample 2 
 
 . 4.71 
 
 
 4.71 
 
 (Top of cam.) 
 
 Sample 3 
 
 4.82 
 
 
 4.82 
 
 (One-third gone.) 
 
 Sample 4 
 
 .4.83 
 
 4.74 
 
 4.78 
 
 (Two-thirds gone.) 
 
 Sample 5 . 
 
 .4.73 
 
 4.82 
 
 THIRD 
 
 4.77 
 
 TRIAL. 
 
 (Bottom of can.) 
 
 
 a. 
 
 b. 
 
 Average 
 
 
 Sample 1 . 
 
 . 4.20 
 
 4.16 
 
 4.18 
 
 (Top of can.) 
 
 Sample 2 
 
 4.11 
 
 4.00 
 
 4.05 
 
 (One-fourth gone.) 
 
 Sample 3 
 
 4.13 
 
 4.0.1 
 
 4.07 
 
 (One-half gone.) 
 
 Sample 4 
 
 . 4.15 
 
 4.04 
 
 4.09 
 
 (Three-fourths gone) 
 
 Sample 5 . 
 
 . . 4.01 
 
 4.00 
 
 4.00 
 
 (Bottom of can.) 
 
90 
 
 Milk and If a Products. 
 
 These I'esults were aljundaiitly confirmed by a sim- 
 ilar series made Ijy Dean in Canada*. 
 
 Till' i-cnioval of the covers of the cans in the 
 dnsty and dirty streets always resnlts in considerable 
 contamination (jf the milk, hence the practice of 
 lintting' the milk into Itottles npon 
 tlic farm, and deliverinj^' these bot- 
 tles inta<'t to tlie consumer, has 
 raiiidly increased sinc(.' its introduc- 
 tion, some ten years ago. When 
 the l)Ottles are used, tlic milk should 
 Ijc put into them as s(jon as it is 
 drawn, strained and cooled ; they 
 should then be sealed and kept in a 
 cool plai/c until i-eady for delivery. 
 This method of delivery, although 
 it entails a greater exi)ense in outfit 
 and transportation and a consider- 
 able loss from })reakage, is nnich to 
 be preferred to the old manner. 
 
 Milk so handled, and kept at a 
 temperature Tjetween 45'' and 50 
 E., should lie in good condition 
 sixty hours after it is drawn. Its life can be pro- 
 longed by pasteurization, and the liability to trans- 
 mission f)f diseases through the milk at the same 
 time reduced to a minimum, liut whether pasteuriza- 
 tion should be relied upon for these purposes is 
 still somewhat of an open ((uestitin. In so far as 
 imnuinity from diseases which may be present in the 
 
 < ' rnn m n ii 
 ' milk shiiii.iiiL' 
 
 *^UDtiirio Agricultuml Collegu, Bulletin No. CG. 
 
Healthf Illness of Skimmed Milk. 91 
 
 cows is concerned, official inspection of the herds 
 is undoubtedly a greater safeguard than dependence 
 upon pasteurization or sterilization ; and so far as 
 the liability of transmission of other diseases is con- 
 cerned, the milkman who is careless in regard to 
 the cleansing of his utensils would quite as likely be 
 careless in the pasteurization or sterilization process, 
 so that reliability of the milkman is an important 
 factor in the purity of the milk supply, no matter 
 what other precautions are taken. 
 
 Bad flavors in milk. — Milk may be unfit for con- 
 sumption for reasons other than the presence of 
 dirt or infection with bacterial germs. The cow 
 herself is often responsible for bad flavors in milk. 
 When lactation is far advanced the milk often has 
 a disagreeable salty taste. In extreme cases it may 
 even be described as acrid or bitter. While there 
 is nothing particularly unwholesome about such milk, 
 its bad flavor makes it unfit for food, and if the 
 cow is within two months of calving, she should be 
 allowed to go dry at once. If the time before calv- 
 ing is longer than this, the bad flavor may often be 
 remedied by taking care that the. cow has plenty of 
 succulent food, as roots or silage, and particularly 
 that the proportion of dry, fibrous food is reduced 
 to a minimum. 
 
 Digestive disorders of any sort in the cow are 
 frequently accompanied by strong flavors in the 
 milk. These flavors are not to be attributed to the 
 food, but to the bad condition of the animal, and 
 they normally tend to disappear when the digestive 
 
92 Milk and Its Products. 
 
 organs regain their tone. Disorders of this sort 
 are especially likely to occur when cows that have 
 been poorly fed during the winter are suddenly turned 
 on fresh rank pasture in the spring. 
 
 Quality of milk for consumption. — The fat is the 
 most variable and the most valuable constituent of 
 the milk, so that milk is ordinarily considered to be 
 of value for human food in proportion to the amount 
 of fat it contains, but where it is to be used as 
 a food in large quantities, the fat may frequently 
 be present in too large quantities for the digestion 
 of many persons. Milk containing about 4 per 
 cent of fat is probably an ideal food for the gen- 
 eral mass of human beings. If there is above 5 
 per cent of fat the other solids are somewhat out 
 of proportion, and many are likely to have trouble 
 with their digestion from using large amounts of 
 such milk. On the other hand, if there is less 
 than 3 per cent of fat, the casein and other solids 
 are in too great proportion to the fat, and are less 
 readily digested. The question of the healthfulness 
 of milk from which a large part of the fat has been 
 removed is one frequently discussed. The removal of 
 the fat does not thereby in any way injure the other 
 solids ; they are still there, and still as useful for 
 food as before the fat was removed, only in con- 
 suming such milk as food the fat must be supplied 
 in some other way. For the person of vigorous 
 digestion, who for reasons of economy desires to 
 supply the fat required by his system in some 
 cheaper form than that of milk fat, skimmed milk is 
 
Legal Standards for Milk. 93 
 
 a wholesome and nutritious article of diet, which 
 furnishes to the system almost the same sort of 
 nutrients that lean meat, eggs, or foods of like na- 
 ture do, and no one should be debarred by legisla- 
 tive or municipal enactment from using such an 
 article of food if he so desires. 
 
 Control of milk supply. — Since milk is so extremely 
 variable in quality, and is so easily adulterated ; 
 since often considerable variations are not readily 
 detected ; above all, because the amount of milk 
 used by any given person or family is compara- 
 tively small, the consumer of milk is almost 
 wholly at the mercy of the producer and dealer, and 
 must rely for a good product very largely upon their 
 honor. The state has recognized this, and to pre- 
 vent imposition by unscrupulous people, has in 
 various ways sought to regulate the sale of milk and 
 like products. The chief means used has been to 
 establish arbitrary standards of quality, and to subject 
 to fine those dealers whose goods should be found 
 to be below the required standard. The standards 
 established by various states and municipalities have 
 varied widely. From 2.5 to 3.7 per cent of fat, 
 and from 11.5 to 13 per cent of total solids, have 
 been the minimum requirements. (See Appendix C.) 
 These standards, while efRicient in securing honest 
 dealing where they are rigidly enforced, nevertheless 
 may work injustice, so far as the honesty of the 
 dealer is concerned, under various circumstances, and 
 may prevent the production and sale of a compara- 
 tively low quality product at a reasonable price. It 
 
94 • Milk and Its Products. 
 
 would seem, therefore, that the best means of regulat- 
 ing the traffic in milk would be, not to set up an 
 artificial standard to which all must come, but to 
 require each individual dealer to guarantee his own 
 standard, and hold him responsible if his milk were 
 found below. In this way it would be possible to 
 sell milk of various qualities, from strictly skimmed 
 to heavy cream, upon a graduated scale of prices, 
 with exact justice to every one. 
 
 Cream for consumption. — Since the introduction of 
 the centrifugal separator, the use of cream as an 
 article of diet and for household purposes has very 
 rapidly increased, and the amount of cream so used 
 now represents a very considerable proportion of the 
 total production of milk. The sale of cream to con- 
 sumers is usually carried on in connection with the 
 sale of milk, and the conditions of care and cleanli- 
 ness necessary in the one case apply equally well to 
 the other. Cream, however, is muek more generally 
 delivered in bottles than is milk, and since the daily 
 quantity used is smaller, there is a greater demand 
 that it should keep sweet for a longer time. For this 
 reason it is still more important that cream should be 
 kept, so far as possible, free from contamination with 
 germs of fermentation, and at a comparatively low 
 temperature from the time it leaves the separator 
 till it goes into the consumer's hands; and of course 
 the fresher and freer from germs the milk is when 
 separated, the better will be the keeping qualities of 
 the resulting ci'eam. Milk containing more than .2 per 
 sent of lactic acid should not be used for the pro- 
 
Cream for Consumption. 95 
 
 duction of cream for commercial purposes. With 
 care it is not difficult to produce cream that will 
 remain sweet for four or five days or even a week. 
 
 Pasteurized cream. — For the sake of its better keep- 
 ing qualities cream that is to be used for commercial 
 purposes is often pasteurized. If it is pasteurized at 
 155° F. for 10 minutes and quickly cooled to 50° F. 
 or below, and bottled in sterile bottles, it will keep, 
 with ordinary precautions, for a week or more. 
 Cream so pasteurized will have no perceptibly cooked 
 taste, but it will be considerably thinner in consist- 
 ency than cream of a like percentage of fat that 
 has not been pasteurized, because the pasteurization 
 greatly and permanently reduces the viscositJ^ Ow- 
 ing to the fact that the "quality" or richness of the 
 cream in fat is, in popular estimation, almost wholly 
 in proportion to its consistency, this lack of con- 
 sistency in pasteurized cream is a matter of consid- 
 erable commercial importance. Babcock and Russel* 
 have shown that the consistency may be restored 
 by the addition of a small amount of a solution 
 of lime in cane sugar, to which they have given 
 the name viscogen. The amount added is so small 
 (about 1 part to 150 of cream) that, while the con- 
 sistency is perfectly restored, the cream is not 
 affected in odor, taste or composition ; but since 
 the addition of anything whatever to milk or cream 
 is prohibited in many states, cream to which vis- 
 cogen has been added should always be sold under 
 a distinctive name, as visco- cream. For preparation 
 of viscogen, see Appendix A. 
 
 *Wisconsin Agricultural Experiment Station, 13th Report, p. 81. 
 
96 Milh and Its Products. 
 
 of cream. — The most unsatisfactory thing 
 about the sale of cream, commercially, is its varying 
 percentage of fat. Since cream is merely milk into 
 which a greater or less proportion of fat has been 
 gathered, it follows that cream may be anything 
 that the seller can induce the puchaser to accept 
 under that name, and may contain anywhere from 6 
 or 8 up to 60 or 70 per cent of fat. Where cream 
 is raised by the gravity process it will contain from 
 18 to 22 per cent of fat ; but where it is separated 
 by centrifugal process the separator can be so 
 adjusted as to take cream of almost any fat con- 
 tent desired. Since cream is almost universally sold 
 without any guarantee as to fat content, the con- 
 sumer has constantly demanded a richer and richer 
 cream till, in some places, cream containing less than 
 40 per cent of fat can scarcely be sold, though a 
 moderately rich cream is quite as useful for table 
 and domestic purposes. The high price that must be 
 had for the extremely rich cream also operates to 
 check consumption. Evidently, then, it would be to 
 the advantage of both seller and consumer if cream 
 were always sold upon a guaranteed fat content, with 
 the price adjusted to varying percentages of fat; but 
 as yet little has been done in this direction, or even 
 in the way of establishing an artificial standard for 
 cream. In Iowa cream must contain at least 15 per 
 cent of fat and in Minnesota and the District of 
 Columbia it must contain 20 per cent. In all other 
 places cream may be anything that can be sold as 
 such. 
 
CHAPTER VI. 
 
 SEPARATION OF CREAM. 
 
 Cream is that part of milk into which a large 
 portion of its fat has been gathered. It is com- 
 posed of the same constituents as milk, but they 
 are not in the same or any constant relative pro- 
 portion. Cream is separated from milk to be con- 
 sumed as food, and, as a matter of convenience, in 
 the manufacture of butter. The separation of cream 
 is always attended with some loss of fat. The per- 
 centage of fat in cream may vary anywhere between 
 8 and 70 per cent. Cream of good quality for com- 
 mercial purposes should contain from 18 to 25 per 
 cent of fat, and very rich cream contains from 35 to 
 40 per cent of fat. Cream is composed of glob- 
 ules of fat, with such part of the water and solids 
 as adhere to them. Its separation from the milk 
 is effected by means of the difference in specific 
 gravity between the globules of fat and the milk 
 serum. The fat in the milk is in the condition 
 known as an emulsion ; that is, in the form of minute 
 globules, which are kept from running together and 
 coalescing by means of the surface tension of their 
 particles and the viscosity of the liquid in which 
 they float; therefore, any condition of the milk 
 
 G (97) 
 
98 Milk and Its Products. 
 
 which tends to increase the surface tension or the 
 viscosity will act as a hindrance towards the sepa- 
 ration of the cream. While the viscosity of the milk 
 serum prevents the particles of fat from uniting 
 into a mass, still the particles have considerable free- 
 dom of movement in the milk, and being of a less 
 specific gravity, of course are acted upon with less 
 intensity by any force to which the milk is subjected. 
 If the milk is allowed to remain at rest in a 
 vessel, the force of gravity, acting with different in- 
 tensities upon the globules of fat and the milk serum, 
 will cause the particles of fat to gather together 
 near the surface of the liquid. In so gathering, 
 they carry with them certain of the milk con- 
 stituents, and the layer of fat globules and adher- 
 ing particles we call cream. From time immemo- 
 rial, and until within a very recent date, the 
 force of gravity, acting in the way indicated, has 
 been the only means used for separating cream from 
 milk. Now machines are in use that effect a sepa- 
 ration of the cream from milk by means of centrif- 
 ugal force, and at the present time we have three 
 systems of separating cream ; namely, by gravity 
 acting upon a thin layer of milk in a shallow vessel, 
 known as the Shallow Pan System ; secondly, by 
 gravity acting upon a deeper mass of milk, usually 
 submerged or partially submerged in water, known 
 as the Deep Setting System ; and thirdly, by ma- 
 chines making use of centrifugal force, known as 
 the Centrifugal or Separator System. The quality 
 of the cream for consumption or for purposes of 
 
Systems of Separating Cream. 99 
 
 manufacture is not affected either one way or the 
 other by any of these three systems, so that their 
 relative economy rests wholly upon the complete- 
 ness, cost and ease of separation. 
 
 Since the separation of cream from milk is al- 
 ways attended with some loss of fat, it is pertinent 
 to inquire as to the necessity of any separation of 
 the cream when butter is to be made. It is per- 
 fectly possible to manufacture butter directly, by 
 churning whole milk without separating cream, and 
 undoubtedly the first churns were skins of animals, 
 into which the whole milk was placed and then 
 agitated until the butter was brought ; but under 
 good conditions it is not possible to so completely 
 remove the fat from the milk by a churning process 
 as by a creaming process ; so that while there is 
 some loss in separating the cream, there is usually 
 a greater loss in churning the butter from the whole 
 milk. Even when the loss of fat in the butter- 
 milk is no greater than the loss of fat in the 
 skimmed milk, the greater amount of labor required 
 to churn the whole mass of milk still renders cream- 
 ing an economical practice in the manufacture of 
 butter. 
 
 Gravity creaming. — In separating cream by force 
 of gravity, there is a greater loss of fat, a longer 
 time required, and the various conditions affecting 
 the milk have a greater influence upon the creaming 
 than when centrifugal separation is used. The 
 conditions of the milk that affect the creaming by 
 the gravity process are : First, the size of the fat 
 
100 Milk and Its Products. 
 
 globules ; second, the amount of solids not fat in 
 the milk ; third, the character of the solids not 
 fat. The larger the fat globules the more readily 
 they separate from the milk, since the larger the 
 sphere the less the ratio between the surface and 
 the mass, so that a large fat globule meets with pro- 
 portionately less resistance because of the viscosity 
 of the milk than a small one. The size of the fat 
 globules is to a great extent a characteristic of the 
 breed and individuality of the animal, but cows 
 newly calved secrete larger fat globules than those 
 in advanced periods of lactation ; consequently we 
 find that the milk from new milch cows is more 
 readily creamed than from those long in milk. 
 The amount of solids not fat affects creaming by 
 the gravity process because of the difference it effects 
 in the specific gravity of the fat and milk serum. 
 The solids not fat are all heavier than water, and 
 in the milk are in a state of solution or semi -solu- 
 tion ; hence, an increase in the amount of solids not 
 fat increases the specific gravity of the milk serum 
 in which they are dissolved, and makes the differ- 
 ence between the specific gravity of the fat and 
 milk serum greater and the separation of the fat 
 easier. The proportion of solids not fat is in- 
 fluenced by the period of lactation and, to a con- 
 siderable extent, by the character of the food. Cows 
 far advanced in lactation often give milk extremely 
 rich in solids not fat. Cows fed on dry food give 
 milk containing less water than those fed on watery 
 or succulent foods. In so far as these conditions 
 
Gravity Processes of Creaming. 101 
 
 increase the amount of solids not fat, we should ex- 
 pect such milk to be more easily creamed, but the 
 favorable effect of the increase of solids is more 
 than counterbalanced by the unfavorable effect of 
 the character of the solids. Of the solids not fat, 
 albumin, casein, sugar and ash increase the viscos- 
 ity of the milk in the order named, and of these 
 the casein is more subject to variation, so that the 
 increase in the proportion of solids not fat ordi- 
 narily means an increase in casein, and this means 
 a largely increased viscosity. And the increase in 
 viscosity tends to prevent the separation of the fat 
 more than the increase in specific gravity tends to 
 aid it. In general, the conditions which bring about 
 an increase in the viscosity of the milk occur at the 
 same time as the fat globules are growing smaller, so 
 that we find a wide range of variability in the ease 
 and completeness with which cream may be separated 
 by gravity process. 
 
 Shallow pan creaming. — This is the oldest method 
 of separating cream from milk, and notwithstanding 
 the rapid changes that have taken place in cream- 
 ing methods since the introduction of centrifugal 
 separators, large amounts of butter are still made 
 from cream separated in this way. The conditions 
 most favorable for a complete separation of the fat 
 in the shallow pan system are, that the milk should 
 be put at rest in the pans as quickly as possible 
 after it is drawn, that it should cool with a fair de- 
 gree of rapidity to a temperature of 60° F., and that 
 it should remain as nearly as may be constantly at 
 
102 MilTe and Its Products. 
 
 that temperature for at least thirty -six hours. 
 Further, since the milk must remain for so long a 
 time, it is essential that the atmosphere to which it 
 is exposed be pure and free from currents of air 
 and particles of dust. These conditions can be 
 secured in a clean, cool, well ventilated cellar. 
 In the shallow pan system, the depth of milk should 
 be from 2 to 4 inches. Occasionally water, usually 
 running water, is used to secure a quick cooling 
 and more even temperature surrounding the milk, 
 and when this is done the depth of the milk may 
 be increased to 4 or 6 inches. Under the shallow 
 pan system, the cream is separated from the milk 
 by removing it from the surface with a thin flat 
 instrument, usually made of tin, and called a 
 skimmer. In this method of removal, it is not 
 possible to completely remove all the cream that has 
 risen to the surface, and in removing the cream 
 more or less of the milk is taken with it, so that 
 in the process of skimming there is a considerable 
 loss of fat and a thin cream is always obtained ; 
 but even if the losses in the skimming operation 
 could be obviated, the separation of the particles of 
 fat in the shallow pan system is less complete than 
 in either of the others. Under ordinarily good con- 
 ditions, 20 per cent of the fat in the milk is lost 
 when the shallow pan system is used. Skimmed milk 
 containing less than .5 of 1 per cent of fat is 
 rarely obtained under this system. 
 
 Deep setting system. — About thirty years ago it 
 was discovered that if milk could be set in vessels 
 when first drawn, and rapidly cooled to a tempera- 
 
Theory of Beep Setting System. 103 
 
 ture of about 40° F., and held at that temperature 
 for twelve to twenty - four hours, not only could 
 the depth be increased from 4 to 20 inches, but the 
 separation was much more complete in a shorter 
 time. In order to bring about . quick cooling, ves- 
 sels not more than a foot in diameter were used, and 
 water, either from cold springs or containing ice, 
 was used as the refrigerant. Two essentials, then, 
 for complete creaming by this system are the rapid 
 and immediate cooling of the milk to 40° F., and 
 a sufficient supply of ice to maintain this tempera- 
 ture for twenty - four hours. Under these condi- 
 tions the fat may be so completely separated that 
 not more than .2 of 1 per cent of fat is left in the 
 skimmed milk. Various devices have been used, 
 the best known of which is the Cooley system, in 
 which the cans are not only surrounded by ice- 
 cold water, but completely submerged in it, the 
 chief effect of the submerging being to guard the 
 milk against contaniination through the atmosphere. 
 The same conditions as to the character .of the milk 
 affect completeness of separation in both the shallow 
 pan and deep setting systems, but no completely 
 satisfactory explanation has ever been assigned as a 
 reason why the fat globules should rise more 
 rapidly and ihore completely through 20 inches of 
 milk at a temperature of 40° F. in the deep setting 
 system, than through 4 inches at a temperature of 
 60° -70° F. in the shallow pan system. 
 
 It has been asserted that because water is a 
 better conductor of heat than fat, it will cool more 
 rapidly than the fat, and will increase in density 
 
104 Milk and Its Products. 
 
 till its maximum density is reached at about 40 F., 
 at which temperature the difference between the. 
 specific gravity of the water or milk serum and the 
 fat wiU be at its greatest, and the separation of the 
 fat for that reason promoted. But while the water 
 does cool faster than the fat, the fat shrinks or 
 increases in density much faster than the water, 
 so that the difference in specific gravity between the 
 two is no greater, and in fact less, at low tempera- 
 tures than at high ones. Further, the viscosity of 
 the milk serum is much increased at low tempera- 
 tures, so that the favorable influence of low tempera- 
 tures cannot be explained upon these grounds. 
 Arnold* attempted to explain the favorable influence 
 wholly upon the relative contraction of the fat and 
 serum, as follows : 
 
 Water is a better conductor of heat than fat ; hence when 
 the tempera.ture of milk varies either up or down, the water 
 in the milk feels the effect of heat or cold sooner than the 
 fat in the cream does, therefore the cream is always a little 
 behind the water in swelling with heat or shrinking with cold, 
 thus diminishing the difference between the specific gravity of 
 the milk and cream when the temperature is rising, and in- 
 creasing it when the temperature is falling. 
 
 But that this explanation is not sufficient, Bab- 
 cock t has shown thus : 
 
 Though it is true that water is a better conductor of heat 
 than fat, the small size of the fat globules renders it impossible 
 that, under any circumstances, there can be more than a small 
 fraction of a degree difference between the temperature of the 
 fat and that of the milk serum. Moreover, within the limits 
 of temperature practical for creaming (90° P. to 40° P.), the 
 
 * American Daii7ine, p. 210. 
 
 tWiscoTiRln Agricultural Experiment Station, Bull, 18, p. 24. 
 
Effect of Fibrin. 105 
 
 coefficient of expansion of butter fat is more than three times as 
 great as that of water, so that in order to maintain the same 
 relative difference in their specific gravities, when the tempera- 
 ture is falling, the milk serum must cool more than three times 
 as rapidly as the fat. In other words, when the milk serum has 
 cooled from 90° F. to 40° F., or through 50°, the fat globules 
 should have lost less than 17°, and should still have a tempera- 
 ture of over 73° F., a difference between the temperature of the 
 fat and serum of more than 33°. Such a condition is mani- 
 festly impossible, but any less difference than this would cause 
 the fat to become relatively heavier than at first, and would 
 operate against the creaming. 
 
 On the whole, the most satisfactory explanation of 
 the good effect of the low temperature in the deep 
 setting system is that advanced by Babcock,* that 
 the presence of fibrin in milk, especially when it has 
 coagulated in the form of threadlike masses, permeat- 
 ing the fluid in all directions, offers a considerable 
 obstacle to the rising of the fat globules. The sudden 
 reduction of the temperature quickly after the milk 
 is drawn, by preventing the formation of these 
 fibrin clots or threads, aids in the separation of the 
 fat. This would be entirely satisfactory were it not 
 for the fact that it has been shown that while it 
 is usually of advantage to cool the milk imme- 
 diately after it is drawn, in some cases, at least, 
 the setting and cooling may have been delayed for 
 a time long enough to permit the formation of 
 fibrin clots without appreciable effects upon the sep- 
 aration, as the following tables t very clearly show, 
 the efficiency of creaming being measured by the 
 percentage of fat in the skimmed milk: 
 
 *Loc. cit. 
 
 tComell University AKricultural Experiment Station, Bull, No. 29, p. 73. 
 
106 
 
 Milk and Its Products. 
 
 Effect of delayed setting upon creaming. 
 
 
 u 
 
 1 
 1 
 
 at 
 
 a 
 
 1 
 
 Pi 
 
 1 
 
 I. 
 Set at once. 
 
 Date, 
 
 1890. 
 
 i 
 
 3 
 
 1 
 
 A 
 
 (£1 
 
 1 Dee. 24, p. M. . . . 
 
 2. Dec. 25, A, M. 
 
 3. Deo. 25, P. M. 
 
 4. Deo. 26, A. M. 
 
 5. Deo. 26, p. M. . . . 
 
 6. Dec. 26, A. M. 
 
 7. Dec. 26, P. M. . 
 
 8. Deo. 27, A. M. . . 
 
 13 
 
 8.5 
 12 
 
 9.75 
 16 
 
 8.25 
 14 
 
 9 
 
 40 
 40 
 40 
 40 
 40 
 40 
 40 
 40 
 
 3.90 
 3.45 
 4.05 
 
 4.10 
 4.15 
 4.00 
 3.90 
 
 35.5 
 
 18.5 
 
 37 
 
 29 
 
 36 
 
 92 
 86 
 86 
 88 
 90 
 
 .57 
 .56 
 .59 
 .55 
 
 .24 
 
 Average of all 
 Average Nos. 1-5 
 
 11 
 
 40 
 
 3.94 
 
 
 88 
 
 .50 
 .50 
 
 
 II. 
 Delayed— kept warm. 
 
 III. 
 Delayed— cooled. 
 
 Date, 
 1890. 
 
 
 i 
 1 
 
 c 
 
 1 
 
 il 
 
 1 
 
 1 
 1 
 
 1 
 p. 
 
 a 
 
 ■si 
 
 SB 
 
 il 
 
 1. Dec. 24, P. M. 
 
 2. Dee. 25, A. M. 
 
 3. Dec. 25, p. m. 
 
 4. Dec. 26, A. M. 
 
 5. Deo. 26, P. M. 
 
 6. Dee. 26, A. M. 
 
 7. Deo. 26, P. M. 
 
 8. Dec. 27, A. M. 
 
 24.5 
 
 18.5 
 
 37 
 
 30.25 
 
 36 
 
 37.5 
 
 24 
 
 74 
 
 60 
 45 
 45 
 
 130 
 75 
 
 205 
 90 
 
 210 
 
 88 
 84 
 84 
 82 
 90 
 92 
 90 
 95 
 
 .59 
 .56 
 .47 
 .68 
 .22 
 .68 
 .49 
 .68 
 
 30 
 
 75.5 
 
 61.5 
 
 37.5 
 23.5 
 74 
 
 f.O 
 
 220 
 
 60 
 
 205 
 
 90 
 
 210 
 
 68 
 62 
 74 
 
 58 
 65 
 64 
 
 .64 
 .55 
 .53 
 
 .66 
 .65 
 .51 
 
 Average of all 
 Average Nos. 1-5 
 Average " 6-8 
 
 
 107 
 
 88 
 
 .55 
 .50 
 .58 
 
 
 141 
 
 65 
 
 .59 
 .57 
 .60 
 
Effect of Delay in Beep Setting System. 107 
 
 The milk was divided into three portions ; one was set at 
 once, one was delayed for an hour, but kept up to a tempera- 
 ture of 92 in a water bath, and the third was put in the open 
 air and allowed to cool for an hour before set. In the cases 
 of delay, the milk was stirred up just before it was placed in 
 the creamer, and all the settings were made in Cooley cans, in 
 ice water. 
 
 The trials reported under the same number, with the excep- 
 tion of the first and second, are comparable, as they were made 
 from different portions of the same samples of milk. In num- 
 bers 1 to 5, inclusive, the delayed sample (Column II.) was 
 kept warm in a water bath ; in numbers 6 to 8 the milk 
 used had been carried about on the route, and the delayed 
 sample was heated up after having been allowed to cool. 
 
 From a similar series of experiments Jordan* 
 concluded : 
 
 That with herds of ordinary size, it will not be profitable 
 to submit to any great inconvenience in order to place the 
 milk in ice water immediately after it is drawn. In a half 
 hour to an hour, milk does not seem to cool sufficiently to ma- 
 terially affect the completeness with which cream will rise. 
 
 In order to overcome certain dilficulties that often 
 occur in raising cream by deep setting process, dilu- 
 tion of the milk with water has been recommended, 
 usually under one of the three following conditions: 
 
 1st. Dilution with one-fourth to one-third of hot 
 water, 135° F., and setting in, deep cans at a tem- 
 perature as low as can be obtained without the use 
 of ice, not below 55°. 
 
 2d. Dilution with one -half to equal quantities of 
 
 ♦Maine Agr. Exp. Sta. Kept. 1890, Part II. page 48. 
 
108 Milk and Its Products. 
 
 cold water, and setting under the same conditions as 
 above. 
 
 Both of these being intended as substitutes for the 
 use of ice in cool deep setting in the summer time. 
 
 3d. Dilution with one -third to one -fourth of hot 
 water (135°), setting in deep cans in ice water (40 F.). 
 
 This last intended to overcome the difficulty of 
 complete creaming often found in the fall and early 
 winter with the milk of cows far advanced in the 
 period of lactation. 
 
 The idea is that the increased fluidity imparted to 
 the milk by the water would facilitate the separa- 
 tion of the fat globules. During the winters of 
 1888-9 and 1889-90 very little ice could be harvested 
 through the dairy regions of the northeastern United 
 States, and in the summer following this idea of 
 dilution was widely advocated and considerably prac- 
 ticed ; but experience and experiment* have shown 
 that while dilution may be of some advantage when, 
 for lack of a supply of ice or other reasons, it is 
 not possible to secure a temperature below 60° F., 
 it can in no case be considered a satisfactory sub- 
 stitute for setting the cans in water at a tempera- 
 ture of 40° F. 
 
 The amount of advantage which may be obtained 
 where dilution is practiced, as measured by the per- 
 centage of fat in the skimmed milk, is seen in the 
 following tables (on pages 109 and 110), taken from 
 Bulletin No. 39 of the Cornell University Agricultural 
 Experiment Station : 
 
 * Vermont Agricultural Experiment Station, 4th Ann. Rept. p. 100. 
 
Effect of Dilution in Beep Setting System. 109 
 
 Diluted and undiluted 
 
 milk set in water at a temperature 
 of 60° F. 
 
 
 Lte, 
 92. 
 
 i 
 
 i 
 2 
 
 Temperatures F. 
 
 1 
 
 a 
 
 s 
 a 
 
 I 
 
 n 
 
 Diluted. Not diluted. 
 
 18 
 
 M 
 
 135 
 
 
 1 
 
 |a 
 si 
 
 §1 
 
 .Se3 
 
 
 11 
 
 |a _ 
 ^11 
 
 
 
 s 
 
 fc 
 
 i 
 
 84 
 
 & 
 
 o 
 
 S 
 
 " 
 
 PM 
 
 PM 
 
 fe"" 
 
 Ah 
 
 h 
 
 Teb. 
 
 19 . 
 
 54 
 
 18 
 
 97 
 
 65 
 
 60 
 
 12 
 
 4.2 
 
 1.07 
 
 .89 
 
 
 
 
 19 . 
 
 72 
 
 
 84 
 
 
 84 
 
 65 
 
 59 
 
 13 
 
 4.2 
 
 
 
 1.33 
 
 1.09 
 
 
 22 . 
 
 54 
 
 18 
 
 90 
 
 136 
 
 99 
 
 64 
 
 59.5 
 
 12.5 
 
 4.2 
 
 .52 
 
 .43 
 
 
 
 
 22 . 
 
 72 
 
 
 90 
 
 
 90 
 
 64 
 
 57.5 
 
 14.5 
 
 4.2 
 
 
 
 .97 
 
 .77 
 
 
 23 . 
 
 54 
 
 18 
 
 89 
 
 135 
 
 101 
 
 66 
 
 60.75 
 
 11.25 
 
 4.3 
 
 .80 
 
 .68 
 
 
 
 
 23 . 
 
 72 
 
 
 89 
 
 
 89 
 
 66 
 
 58.50 
 
 13.5 
 
 4.3 
 
 
 
 I.IZ 
 
 .91 
 
 
 28 . 
 
 54 
 
 18 
 
 88 
 
 134 
 
 98 
 
 57 
 
 68 
 
 14 
 
 
 .35 
 
 .28 
 
 
 
 
 28 . 
 
 72 
 
 
 88 
 
 
 88 
 
 57 
 
 57 
 
 15 
 
 
 
 
 .85 
 
 .51 
 
 
 29 . 
 
 54 
 
 18 
 
 86 
 
 134 
 
 97 
 
 60 
 
 59.75 
 
 12.25 
 
 4.4 
 
 .68 
 
 .56 
 
 
 
 
 29 . 
 
 72 
 
 
 86 
 
 
 86 
 
 60 
 
 58 
 
 14 
 
 4.4 
 
 
 
 1.18 
 
 .95 
 
 Mar. 
 
 1 . 
 
 54 
 
 13 
 
 86 
 
 135 
 
 96 
 
 60 
 
 61 
 
 11 
 
 4.1 
 
 .68 
 
 .58 
 
 
 
 
 1 . 
 
 72 
 
 
 86 
 
 
 86 
 
 60 
 
 58.5 
 
 13.5 
 
 4.1 
 
 
 
 .96 
 
 .78 
 
 
 13 . 
 
 54 
 
 18 
 
 86 
 
 135 
 
 96 
 
 60 
 
 60.75 
 
 11.25 
 
 4.3 
 
 .85 
 
 .72 
 
 
 
 
 13 . 
 
 72 
 
 
 86 
 
 
 86 
 
 60 
 
 57.75 
 
 14.25 
 
 4.3 
 
 
 
 .82 
 
 .66 
 
 
 14 . 
 
 27 
 
 9 
 
 84 
 
 136 
 
 96 
 
 68 
 
 29.5 
 
 6.5 
 
 3.9 
 
 .88 
 
 .72 
 
 
 
 
 14 . 
 
 36 
 
 
 84 
 
 
 84 
 
 58 
 
 30 
 
 6 
 
 3.9 
 
 
 
 1.14 
 
 .95 
 
 
 15 . 
 
 27 
 
 9 
 
 86 
 
 132 
 
 95 
 
 58 
 
 30 
 
 6 
 
 3.9 
 
 .73 
 
 .61 
 
 
 
 
 15 . 
 
 36 
 
 
 86 
 
 
 86 
 
 58 
 
 29.5 
 
 6.5 
 
 3.9 
 
 
 
 1.25 
 
 1.02 
 
 
 26 . 
 
 27 
 
 9 
 
 88 
 
 136 
 
 101 
 
 66 
 
 29.5 
 
 6.5 
 
 4.1 
 
 
 
 
 
 
 27 . 
 
 36 
 
 
 88 
 
 
 88 
 
 56 
 
 28.5 
 
 7.5 
 
 41 
 
 
 
 .67 
 
 .53 
 
 
 27 . 
 
 54 
 
 18 
 
 90 
 
 135 
 
 100 
 
 64 
 
 60.25 
 
 11.75 
 
 4.5 
 
 .81 
 
 .68 
 
 
 
 
 27 . 
 
 36 
 
 
 90 
 
 
 90 
 
 64 
 
 30 
 
 6 
 
 4.5 
 
 
 
 .70 
 
 .58 
 
 
 28 . 
 
 27 
 
 9 
 
 88 
 
 138 
 
 102 
 
 61 
 
 31 
 
 5 
 
 4 
 
 
 
 
 
 
 28 . 
 
 36 
 
 
 88 
 
 
 88 
 
 61 
 
 30 
 
 G 
 
 4 
 
 
 
 1.21 
 
 1.01 
 
 
 31 . 
 
 27 
 
 9 
 
 87 
 
 135 
 
 102 
 
 62 
 
 30 
 
 6 
 
 4.1 
 
 .93 
 
 .78 
 
 
 
 
 31 . 
 
 36 
 
 
 87 
 
 
 87 
 
 62 
 
 29.75 
 
 6.25 
 
 4.1 
 
 
 
 1.17 
 
 .97 
 
 Apr 
 
 2 . 
 
 27 
 
 9 
 
 91 
 
 135 
 
 103 
 
 65 
 
 30 
 
 6 
 
 4.7 
 
 1.08 
 
 .90 
 
 
 
 2 . 
 
 36 
 
 
 91 
 
 
 91 
 
 65 
 
 29 
 
 7 
 
 4.7 
 
 
 
 1.68 
 
 1.35 
 
 
 4 . 
 
 27 
 
 9 
 
 92 
 
 135 
 
 102 
 
 62 
 
 29 
 
 7 
 
 4.2 
 
 .31 
 
 .25 
 
 
 
 
 4 . 
 verage 
 
 36 
 
 
 92 
 
 
 92 
 
 62 
 
 29 
 
 7 
 
 4.2 
 
 
 
 .92 
 
 .74 
 
 A 
 
 
 
 
 
 
 
 .76 
 
 .62 
 
 1.05 
 
 .85 
 
110 
 
 Milk and Its Products. 
 
 Diluted and undiluted milk set in water at a temperature of 
 40°-45° F. 
 
 
 
 
 Temperatures F. 
 
 
 M 
 
 
 Dilu 
 
 ted. 
 
 Not diluted. 
 
 Datti, 
 
 
 
 
 
 r'S 
 
 §f 
 
 
 8" 
 
 1892. 
 
 
 
 M 
 
 s 
 
 
 1 
 
 a 
 
 a 
 
 
 Si; 
 
 SI 
 
 c 
 
 1" 
 
 = E 
 S3 
 
 -a 
 
 
 i 
 
 1 
 
 g 
 
 
 i 
 
 O 
 
 3 
 
 CO 
 
 o 
 
 S6= 
 
 I, j2 
 
 .11 
 
 J2 . 
 
 
 Feb. 20 
 
 54 
 
 18 
 
 87 
 
 140 
 
 100 
 
 44 
 
 58 
 
 14 
 
 4.4 
 
 .32 
 
 .26 
 
 
 
 " 20 . 
 
 72 
 
 
 87 
 
 
 87 
 
 44 
 
 54.25 
 
 1,.75 
 
 4.4 
 
 
 
 .25 
 
 .19 
 
 " 21 . 
 
 54' 
 
 18 
 
 88 
 
 136 
 
 99 
 
 44 
 
 57.5 
 
 14.5 
 
 4.4 
 
 .20 
 
 .16 
 
 
 
 " 21 . 
 
 72 
 
 
 88 
 
 
 .88 
 
 44 
 
 53.75 
 
 18.25 
 
 4.4 
 
 
 
 .24 
 
 .18 
 
 " 24 . 
 
 54 
 
 18 
 
 87 
 
 134 
 
 97 
 
 45 
 
 56.25 
 
 15.75 
 
 4.2 
 
 .23 
 
 .18 
 
 
 
 " 24 . 
 
 72 
 
 
 87 
 
 
 87 
 
 45 
 
 53.5 
 
 18.5 
 
 4.2 
 
 
 
 .17 
 
 .13 
 
 " 25 . 
 
 54 
 
 18 
 
 90 
 
 134 
 
 100 
 
 46 
 
 57 
 
 15 
 
 4.4 
 
 .23 
 
 .18 
 
 
 
 " 25 . 
 
 72 
 
 
 90 
 
 
 90 
 
 46 
 
 54.25 
 
 17.75 
 
 4.4 
 
 
 
 .26 
 
 .20 
 
 Mar. 30 
 
 27 
 
 9 
 
 86 
 
 135 
 
 100 
 
 44 
 
 29 
 
 7 
 
 
 .32 
 
 .26 
 
 
 
 " 30 
 
 36 
 
 
 86 
 
 1 86 
 
 44 
 
 27 
 
 9 
 
 
 
 
 .35 
 
 .26 
 
 " 17. 
 
 27 
 
 9 
 
 88 
 
 136 97 
 
 44 
 
 29 
 
 7 
 
 4.7 
 
 .11 
 
 .09 
 
 
 
 " 17 ■ 
 
 18 
 
 
 88 
 
 
 88 
 
 44 
 
 13.5 
 
 4.5 
 
 4.7 
 
 
 
 .18 
 
 .14 
 
 " 30. 
 
 27 
 
 9 
 
 86 
 
 135 
 
 100 
 
 44 
 
 28 
 
 8 
 
 5 
 
 .08 
 
 .06 
 
 
 
 " 30 . 
 
 18 
 
 
 86 
 
 
 86 
 
 44 
 
 13 
 
 5 
 
 5 
 
 
 
 .12 
 
 .09 
 
 April 5 
 
 27 
 
 9 
 
 90 
 
 138 
 
 103 
 
 46 
 
 29.75 
 
 6.25 
 
 3.3 
 
 .31 
 
 .23 
 
 
 
 ^' 5 . 
 
 18 
 
 
 90 
 
 
 00 
 
 46 
 
 14.5 
 
 3.5 
 
 3.3 
 
 
 
 .28 
 
 .23 
 
 Average 
 
 
 
 
 ~F 
 
 
 
 i-- 
 
 .23 
 
 .18 
 
 .23 
 
 .18 
 
 Summing up all of the experiments, the average 
 efficiency of creaming as measured by the percent- 
 age of fat in the skimmed milk would appear to be 
 about as follows : 
 
 Diluted, set at 60° (39 trials) .77 per cent. 
 , Undiluted, set at 60° (30 " ) 1.00 " 
 " " 40° (26 " ) .29 " 
 It would seem, therefore, that while, when the 
 milk is set at 60° F. or thereabouts, there is consider 
 able advantage, so far as the efficiency of creaming 
 
Dilution Separator. Ill 
 
 is concerned, in diluting it with 25 per cent of warm 
 water, this dilution cannot be regarded as a sub- 
 stitute for setting without dilution in ice water, and 
 it has the further disadvantage of requiring increased 
 tank capacity. 
 
 About 1897 the idea that dilution with water is 
 an important aid in gravity -creaming broke out with 
 renewed activity. It was especially recommended by 
 the manufacturers of certain forms of cheap tin cans 
 in which dilution was recommended as an essential 
 part of the process. These cans were called gravity 
 "separators" modified by various high-sounding, 
 qualifying phrases, with the evident intention of con- 
 veying the idea that this process was as efficient as 
 centrifugal separation, and large numbers of the 
 "separators" have been sold, mainly to unsuspecting 
 or ignorant farmers, who have been deluded into the 
 idea that they were securing a contrivance equal in 
 efficiency to a centrifugal separator at a small frac- 
 tion of the cost. The form of many of the cans was 
 patented, but it was soon shown* that so far as the 
 process is concerned, the patents were valueless, and 
 trials at several experiment stations showed that dilu- 
 tion in gravity separators, of whatever form, is no 
 more efficacious than has been shown above. For 
 this reason, and because rival manufacturers have 
 become involved in controversies over their various 
 patents, the "dilution separator boom" is, fortunately, 
 likely to be of short duration. 
 
 Centrifugal separation. — The invention, develop- 
 ment and perfection of the centrifugal separator has 
 
 ^Cornell University Asricultural Experiment Station, Bulls. 151 and 171. 
 
112 . Milk and Its Products. 
 
 been the chief factor in revolutionizing methods of 
 butter- making. By its greater efficiency it has pre- 
 vented otherwise unavoidable losses, and by its greater 
 economy of labor it has rendered possible the devel- 
 opment of a profitable industry in many localities 
 where it would have been otherwise impossible. 
 
 In separating cream in a centrifugal machine, the 
 centrifugal force generated in a rapidly revolving 
 bowl is made to take the place of the force of grav- 
 ity acting upon the milk at rest in a vessel. The 
 amount of force generated is so much greater than 
 the force of gravity that the separation of the par- 
 ticles of fat is much more rapid and much more 
 complete. The force, however, acts in a horizontal 
 instead of a vertical direction. In 1877, a patent was 
 granted to Le Feldt & Lentseh for a machine to sepa- 
 rate milk by centrifugal force. This first centrifugal 
 separator consisted merely of a series of buckets hung 
 upon arms swinging from a central axis. When the 
 machine was at rest the buckets assumed a vertical 
 position, but in motion they were thrown out horizon- 
 tally from the arms. The milk was placed in these 
 buckets, the machine set in motion until the cream 
 was separated from the skimmed milk, and when the 
 machine was allowed to come to a stand- still the 
 buckets assumed a vertical position, and the cream 
 was removed from the top in the same way that it 
 was skimmed from any other vessel. From this was 
 evolved a machine consisting of a revolving bowl 
 or drum in which the separation takes place, with 
 arrangements for removing the skimmed milk and 
 
structure of Centrifugal Separator. 
 
 113 
 
 cream without stopping the machine, thus making 
 the separation continuous. The various parts of 
 the machine have been much improved in minor de- 
 tails. At the present time the essential parts of 
 
 u 
 
 Fig. 10. Section of separator bowl of plain or "Hollow Bowl" type. 
 
 a separator are the bowl, with or without internal 
 devices or arrangements to assist in the separation 
 of the cream from the milk, an outlet for the 
 skimmed milk, an outlet for the cream, an inflow for 
 the whole milk, and the proper mechanical means 
 H 
 
114 Milk and Its Products. 
 
 for revolving the bowl. (The more common types of 
 separator bowls are shown in Figs. 10-13.) Usually 
 the bowl is driven in an upright position, but there 
 are separators in which the bowl is driven in a hori- 
 zontal position, and in the greater number of ma- 
 chines the walls of the bowl are cylindrical. In the 
 process of separation the milk flows into the bowl, 
 and, partaking of the centrifugal force, is forced to 
 the extreme outer edge of the bowl. As the milk 
 continues to flow in, the bowl begins to fill from 
 the outside toward the center. The centrifugal force 
 acting more strongly upon those parts of the milk 
 which have the greatest specific gravity, they are 
 thrown to the extreme outside, and the lighter por- 
 tions, the fat globules, with whatever may adhere 
 to them, are forced to the center. Attached to the 
 extreme outer edge of the bowl are one or more 
 tubes, which, bending inward along the side of the 
 bowl, find an opening near the center. These are 
 the outlets for the skimmed milk. From the ex- 
 treme center of the bowl, also leading to the out- 
 side, is the cream outlet. When the bowl becomes 
 filled with milk, the centrifugal pressure will force 
 out through the skimmed milk outlets the milk nearest 
 the outside of the bowl. These outlets are made 
 of such size in comparison with the size of the bowl, 
 the speed of the machine, and the size of the inflow 
 tube, that they have a capacity of discharging the 
 milk from .4 to .9 as fast as it runs in ; the remain- 
 ing contents of the bowl are then forced toward 
 the center, and find an exit through the cream 
 
Theory of Centrifugal Separation. 115 
 
 outlet. In this way the milk as it enters is divided 
 into two portions : one, the larger, drawn from the 
 extreme outer portion of the bowl, consisting of 
 skimmed milk, and the other, the smaller, escaping 
 from the center of the bowl, the cream. A third 
 portion also usually accompanies centrifugal sepa- 
 ration. A part of the semi -solid constituents of 
 the milk, being heavier than the milk serum, are 
 thrown to the outside of the bowl, and adhere to 
 the walls in the form of a creamy or gelatinous mass, 
 which is ordinarily called separator slime. It consists 
 mainly of albuminous matters with some fat globules 
 adhering, and any particles of dirt or foreign mat- 
 ter that maj' be mechanically mixed with the milk. 
 It varies greatly at different times and seasons. 
 Usually the amount is not large, but not infrequently 
 it is sufficient to clog the outlets of the separator after 
 a run of an hour or two. The separator slime is 
 largely composed of matter deleterious to the qual- 
 ity of cream and butter, and its removal is to a 
 great extent a purification of the cream. The various 
 conditions affecting this operation are as follows : 
 
 Conditions affecting the completeness of separa- 
 tion. — The completeness of the separation is depend- 
 ent upon the centrifugal force generated, the rate 
 of inflow, the temperature of the milk, and the 
 physical condition of the milk. 
 
 The amount of centrifugal force generated depends 
 xipon the diameter of the bowl and the velocity of 
 rotation. 
 
 Roughly speaking, the centrifugal force increases 
 
116 Milk and Its Products. 
 
 directly in proportion as the diameter is increased and 
 directly with the square of the velocity. The larger 
 the bowl, then, and the greater the speed, the greater 
 the centrifugal force and the more complete the sep- 
 aration. The rate of inflow of milk a£fects the 
 separation, because the separation is more complete 
 the longer the milk is subjected to the centrifugal 
 force, and the slower the milk flows into a given- 
 sized bowl the longer any particle will be in flowing 
 through it and the more completely will the cream 
 be separated. The temperature of the milk affects 
 the fluidity of the fat globules and their ease of mo- 
 tion upon the other particles of the milk; the warmer 
 the milk the more easUy are they separated. A 
 temperature of 76° to 98° F. is the one commonly 
 employed because of the effect upon the texture of 
 the butter. It is desirable that the milk should be 
 separated at as low a temperature as possible without 
 interfering with the completeness of the separation, 
 so that, other things being equal, that separator is the 
 best that separates the milk at the lowest tempera- 
 ture. The physical condition of the milk affects 
 separation by the centrifugal in the same ways that 
 gravity creaming is affected, but to a very much 
 slighter degree. Small -sized fat globules, viscosity 
 of the milk, and coagulation of part of the casein 
 by incipient fermentations, all tend to make separa- 
 tion more difficult; but in a majority of cases, un- 
 less the milk is so sour as to be coagulated, it may 
 be completely creamed with a centrifugal separator, 
 but will require a slower feeding (a reduction of 10 
 
Relative Amount Skimmed Milk and Cream. 117 
 
 to 15 per cent will usually suffice), and a higher speed 
 of the bowl, or both. 
 
 Conditions affecting the relative amount of skimmed 
 milk and cream. — The relative amount of skimmed 
 milk and cream is affected by the rate of inflow, 
 by the speed of the bowl, by various special con- 
 trivances upon the machines themselves, and to, a 
 slight extent by the temperature of the milk. In 
 the ordinary machine the size of the skimmed milk 
 outlet is fixed, and therefore at a given velocity the 
 outlet will discharge a nearly uniform quantity of 
 fluid. If, then, the milk is turned into the bowl at 
 such a rate that .8 of it escapes through the skimmed 
 milk outlet, we shall have .8 skimmed milk and 
 .2 cream. If now we reduce the rate of inflow 
 by .1, we shall get just as much skimmed milk as 
 before, but only one -half as much cream ; or if the 
 inflow is increased by .1, we shall get the same 
 amount of skimmed milk and once and a half as 
 much cream. If under the first conditions all of the 
 fat was gathered into the cream, we shall have just 
 as complete a separation as before, but will simply 
 get a cream containing a greater or less percentage 
 of fat, provided that the increase of inflow has not 
 increased the total amount above the capacity of the 
 machine. In other words, the greater the inflow, 
 the more cream and the thinner the cream ; the 
 smaller the inflow, the less cream and the richer the 
 cream. These variations can only take place within 
 comparatively narrow limits. If we increase the in- 
 flow too much, we shall soon reach a point at which 
 
118 Milk and Its Products. 
 
 the milk passes so rapidly througli the machine that 
 the separation is not complete, and if we reduce the 
 inflow to such a point that the skimmed milk outlet 
 has a capacity of discharging the milk as fast as it 
 flows in, we shall get a separation until the bowl 
 becomes filled, and then all of the milk will pass 
 out of the skimmed milk outlet in the same condi- 
 tion in which it enters the machine. 
 
 The speed of the machine, also, affects the rela- 
 tive amount of cream and its percentage of fat. The 
 size of the skimmed milk outlet being fixed, the 
 faster the bowl is revolved the greater the capacity 
 of this outlet will be, so that, the rate of inflow 
 remaining uniform, the faster the bowl is revolved 
 the less proportional amount of cream we shall have, 
 and the richer it will be in fat, and vice versa. It 
 must be borne in mind, further, that the speed of 
 the bowl is also an important factor in the complete- 
 ness of separation, and that if the speed is slackened 
 in order to get a greater bulk of cream, there will 
 be danger of incomplete separation. 
 
 Most of the machines have arrangements for reg- 
 ulating the relative amount of skimmed milk and 
 cream without changing the rate of inflow or the 
 speed of the machine. In most of the machines 
 this arrangement is known as a "cream screw," and 
 affects the amount of cream by placing the cream 
 outlet nearer or farther from the center of the bowl; 
 the nearer the center the cream screw is turned, the 
 thicker will be the cream and the smaller the amount. 
 Some of the separators change the proportion of 
 
Modifications in Structure of Bowl. 
 
 119 
 
 cream by increasing or decreasing the capacity of the 
 skimmed milk outlet. If the capacity of the skim- 
 med milk outlet ,be decreased, necessarily the amount 
 of the cream will be. increased, and vice versa. 
 
 The temperature of the milk only slightly affects 
 the proportion of skimmed milk and cream. The 
 warmer the milk, the more fluid it is, and the faster 
 it will pass through the various openings of the ma- 
 chine. Slightly more milk at 85° will run through 
 the same inflow than at 70°, and a large part of 
 this increase will be found in the cream. The 
 pressure of the milk in 
 the vat above the ma- 
 chine will materially af- 
 fect the rate of inflow, 
 and a few inches will 
 make a difference of 
 two or three hundred 
 pounds, per hoar on a 
 large -sized machine. 
 
 Contrivances in the 
 bowl to increase the ef- 
 ficiency of separation. — 
 In the first separators 
 made, the bowl was 
 hollow, and the separa- 
 tion was caused directly 
 by the centrifugal pres- 
 sure acting upon the 
 milk in a mass. In 
 
 ,1 T . ^ . Fig. 11. Section of separator bowl of 
 
 the later maCUineS, Va- the disc or "Alpha" type. 
 
120 
 
 Milk and Its Products. 
 
 rious contrivances have been introduced in the bowl 
 to aid in the completeness of the separation or to 
 increase the capacity. These contrivances have been 
 of two general types : one to break up the wall of 
 milk, and so give the particles of milk and cream 
 a better chance to pass by one another in their 
 passage from the center to the outside of the bowl; 
 the other, a series of interruptions to the passage 
 
 of the milk from 
 its entrance 
 at the center 
 to the outside, 
 causing it to 
 travel a much 
 greater dis- 
 tance and be 
 subjected to the 
 centrifugal forco 
 for a longer 
 time. These 
 contrivances, 
 while adding to 
 the complexity 
 of the machine, 
 have increased 
 the capacity 
 and the effi- 
 ciency of the 
 separation. The best known of these contrivances 
 are the so-called "Alpha" discs or plates, — a series 
 of cup -shaped plates, nearly filling the bowl of the 
 
 Fig. 12. 
 
 Section of separator bowl of ' 
 States " type. 
 
 'United 
 
Mechanical Conditions Affecting Separation. 121 
 
 separator. These Alpha plates nearly double the 
 separating capacity of the hollow bowl of the same 
 
 Fig. 13. Parts of bowl of "United States" type. 
 
 diameter, and at the same time the efficiency of sep- 
 aration is increased. 
 
 Mechanical conditions which affect separation. — Cer- 
 tain peculiarities in the construction or operation of 
 the machine often materially influence the efficiency 
 of separation. One of the most important of these 
 is that the bowl should run steadily and smoothly, 
 without any perceptible jar or trembling. The trem- 
 bling of the bowl may be caused by lack of per- 
 fect balancing in the bowl itself. This can only be 
 remedied by the manufacturer. The bowl may trem- 
 
122 Milk and Its Products. 
 
 ble, also, because the bearings are not perfectly ad- 
 justed ; and, lastly, the bowl may tremble because 
 the machine is not set level or upon a solid founda- 
 tion. A second cause of inefiicient separation is 
 variation in the velocity of the bowl. It is quite as 
 important that the bowl run uniformly as it is that 
 it attain any given rate of velocity. In this re- 
 spect the turbine separators are more likely to be 
 at fault than those run by belt power, and separa- 
 tors turned by hand are more subject to variations 
 than those run by power. 
 
 An engine of ample power, with a good gover- 
 nor, and the power transmitted through an interme- 
 diate rope belt kept perfectly tightened, with well-oiled 
 bearings all around, are the best safeguards to uni- 
 form speed. 
 
 Efficiency of separation in centrifugal machines. — 
 With the centrifugal separator run under perfect con- 
 ditions, there is still a slight loss of fat in the 
 skimmed milk. This need not be greater than .1 
 of 1 per cent. At the present time it is considered 
 that where more than .1 of 1 per cent of fat is left 
 in skimmed milk, a centrifugal machine is not doing 
 perfect work, and numerous trials have shown that 
 the machines of the leading forms can be made to 
 reach this point of efficiency, as may be seen from 
 the following table, * giving the average of a large 
 number of tests made by several agricultural experi- 
 ment stations : 
 
 * Cornell University Agricultural Experiment Station, Bulletin No. 105. 
 
Relative Efficiency of Separators. 
 
 123 
 
 
 Per cent of fat in skimmed milk. 
 
 Name of machine. 
 
 Average. 
 
 Minimum. 
 
 
 
 By series. 
 
 Of all 
 
 Maximum. 
 
 
 
 trials. 
 
 
 
 Aooumulator 
 
 .12 
 
 .11 
 
 .01 
 
 .20 
 
 Alexandra Jumbo 
 
 .22 
 
 .22 
 
 .15 
 
 .33 
 
 Columbia 
 
 .09 
 
 .12 
 
 .05 
 
 .34 
 
 Danish Weston . . 
 
 .10 
 
 .08 
 
 .01 
 
 .25 
 
 DeLaval . ... 
 
 .13 
 
 .09 
 
 .01 
 
 .50 
 
 Sharpies 
 
 .27 
 
 .16 
 
 .05 
 
 .65 
 
 United States . . . 
 
 .18 
 
 .12 
 
 .01 
 
 .60 
 
 Victoria . 
 
 .21 
 
 .16 
 
 .05 
 
 .38 
 
 A series of trials made in Germany* shows a con- 
 siderable variation in the various styles, and, on the 
 whole, a rather less efficiency than has been obtained 
 in this country, as is seen in the table following : 
 
 Name of machine. 
 
 Revolutions 
 of bowl 
 per min- 
 ute. 
 
 Pounds 
 separated 
 per hour. 
 
 Tempera- 
 ture of 
 milk r. 
 
 Per cent 
 
 of fat in 
 
 skimmed 
 
 milk. 
 
 Number 
 
 of trials. 
 
 Alpha B • • 
 
 5,100 
 
 537 
 
 92 
 
 .23 
 
 37 
 
 Alpha Baby 
 
 6,900 
 
 286 
 
 72 
 
 .23 
 
 23 
 
 Baby . . 
 
 6,360 
 
 129 
 
 88 
 
 .18 
 
 15 
 
 Victoria . 
 
 ■ • 
 
 205 
 
 92 
 
 .17 
 
 19 
 
 Small Danish . 
 
 7,241 
 
 288 
 
 90 
 
 .28 
 
 16 
 
 Large Danish 
 
 7,217 
 
 411 
 
 91 
 
 .35 
 
 16 
 
 Adjustable . 
 
 8,640 
 
 363 
 
 70 
 
 .10 
 
 3 
 
 Arnold's 
 
 8,531 
 
 458 
 
 90 
 
 .28 
 
 26 
 
 Medium Brown 
 
 4,037 
 
 268 
 
 91 
 
 .37 
 
 16 
 
 But while all the forms of separators can be made 
 to do perfect work, there is more or less variation 
 
 * Milch Zeitung, xxiii., p. 296. 
 
124 
 
 Milk and Its Products. 
 
 in the work done by the different machines of the 
 same style and manufacture. This variation is due 
 to slight peculiarities in the construction of the in- 
 dividual bowls, and which cannot be detected by 
 the ordinary senses, and only appear upon an ex- 
 amination of the skimmed milk after actual use. 
 These differences are well illustrated in a series of 
 trials made in different factories,* and shown iu 
 detail in the following tables: 
 
 ALEXANDRA JUMBO. 
 
 Bated capacity, S,000 pounds per hour. 
 
 
 
 
 
 
 Average 
 
 
 Pounds 
 
 
 
 No. 
 
 of 
 
 
 Range 
 
 speed of 
 
 Range 
 
 sepa- 
 
 Per cent 
 
 Date. 
 
 of 
 
 milk 
 
 temper- 
 
 of 
 
 bowl. 
 
 of 
 
 rated 
 
 of fat in 
 
 
 fac- 
 
 
 
 temper- 
 
 revolu- 
 
 speed. 
 
 per 
 
 skimmed 
 
 
 tory. 
 
 run. 
 
 
 ature. 
 
 tions per 
 minute. 
 
 
 hour. 
 
 milk. 
 
 Aug. 19. 
 
 7 
 
 3,809 
 
 To 
 
 66-75 
 
 7,200 
 
 7,000-7,400 
 
 1,344 
 
 .25 
 
 " 20. 
 
 8 
 
 
 70 
 
 68-72 
 
 6,985 
 
 6,800-7,200 
 
 1,170 
 
 .15 
 
 " 20. 
 
 8 
 
 
 70 
 
 68-72 
 
 6,585 
 
 6,300-6,900 
 
 1,611 
 
 .20 
 
 " 21. 
 
 9 
 
 5,928 
 
 75 
 
 72-81 
 
 6,900 
 
 6,600-7,100 
 
 1,882 
 
 .20 
 
 , " 23. 
 
 11 
 
 4,052 
 
 84 
 
 80-86 
 
 6,600 16,200-7,400 
 
 1,814 
 
 .33 
 
 Average 
 
 
 
 74 
 
 
 6,854 
 
 
 1,564 
 
 .23 
 
 DE LAVAL, ALPHA NO. 1. 
 
 Bated capacity, ^,500 pounds per hour. 
 
 July 17. 
 
 3 
 
 2,519 
 
 80 
 
 78-85 
 
 5,520 
 
 1 
 4,800-6,100 2,606 
 
 .08 
 
 Aug. 18. 
 
 6 
 
 3,629 
 
 74 
 
 73-76 
 
 5,808 
 
 5,700-6,000 2,592 
 
 .05 
 
 Sep. 16. 
 
 17 
 
 1,187 
 
 72 
 
 71-73 
 
 5,933 
 
 5,800-6,000 2,456 
 
 .08 
 
 '"^ 20. 
 
 22 
 
 4,627 
 
 82 
 
 80-83 
 
 6,071 
 
 6,800-6,200 2,501 
 
 .04 
 
 " 21. 
 
 23 
 
 6,376 
 
 78 
 
 77-W) 
 
 6,044 
 
 0,000-6,200 2,500 
 
 .03 
 
 Oct. 4. 
 
 24 
 
 5,588 
 
 82 
 
 78-85 
 
 5,844 
 
 5,600-6,000 2,747 
 
 .13 
 
 " 4. 
 
 25 
 
 1,802 
 
 86 
 
 85-90 
 
 6,280 
 
 6,000-6,400 2,040 
 
 .03 
 
 Average 
 
 
 
 79 
 
 .... 5,928 
 
 . . 1 2,491 
 
 .06. 
 
 * Cornell University Agricultural Experiment Station, Bulletin No. 105. 
 
Variations in Machines of Same Style. 125 
 
 DE LAVAL, BABY. 
 
 Bated capacity, No. 2, 350; No. 3, 600 pounds per hour. 
 
 Date. 
 
 May 31. 
 
 Sep. 14. 
 '^ 18. 
 
 Average 
 
 No. 
 o£ 
 fac- 
 tory. 
 
 Pounds 
 
 of 
 
 milk in 
 
 ■ whole 
 
 run. 
 
 205 
 146 
 
 Average 
 temper- 
 ature. 
 
 96 
 83 
 
 Kange 
 
 of 
 temper- 
 ature. 
 
 Average 
 speed of 
 bowl, 
 revolu- 
 tions per 
 minute. 
 
 Rev. crank 
 54 
 46 
 46 
 
 49 
 
 Range 
 of 
 
 Pounds 
 separ- 
 ated 
 per 
 hour. 
 
 Per cent 
 
 of fat in 
 
 skimmed 
 
 milk. 
 
 .05 
 .06 
 .16 
 
 DE LAVAL, STANDARD. 
 
 Bated capacity, 1,100 pounds per hour. 
 
 Sep. 19. 
 '^ 10. 
 " 19. 
 
 21 
 21 
 21 
 
 — 
 
 73 
 73 
 72 
 
 71-75 
 71-75 
 71-75 
 
 Rev. bowl 
 7,914 
 8,140 
 8,300 
 
 7,700-8,200 
 7,600-8,400 
 8,000-8,500 
 
 1,020 
 
 930 
 
 1,000 
 
 .25 
 .15 
 .16 
 
 Average 
 
 
 
 73 
 
 
 8,118 
 
 
 983 
 
 .19 
 
 SHARPLES RUSSIAN. 
 
 Bated capacity, Standard, 1,100 pounds; Imperial, 
 per hour. 
 
 2,000 pounds 
 
 July 16. 
 July 16. 
 Aug. 17. 
 Aug. 24. 
 Sept. 14. 
 Sept. 17. 
 Oct. 6. 
 
 2 
 2 
 5 
 12 
 13 
 18 
 18 
 
 
 84 
 88 
 80 
 81 
 85 
 87 
 90 
 
 83-87 
 87-88 
 78-82 
 80-82 
 84-86 
 82-95 
 87-91 
 
 7,775 
 7,183 
 7,800 
 7,700 
 7,433 
 7,558 
 7,675 
 
 7,700-7,900 
 7,000-7,600 
 7,700-7,900 
 7,100-8,300 
 6,800-7,600 
 7,200-7,900 
 7,400-7,900 
 
 2,100 
 2,130 
 1,874 
 1,033 
 1,158 
 1,752 
 1,873 
 
 .40 
 .65 
 .10 
 .05 
 .13 
 .45 
 .38 
 
 1,718 
 4,028 
 2,509 
 3,562 
 2,716 
 
 Average 
 
 
 
 85 
 
 
 7,589 
 
 
 1,703 
 
 .31 
 
 UNITED STATES. 
 
 Bated capacity, 2,000 pounds per hour. 
 
 July 18. 
 Aug. 22. 
 Sept. 15. 
 Sept. 15. 
 Sept. 18. 
 
 4 
 10 
 15 
 16 
 20 
 
 
 83 
 81 
 94 
 88 
 73 
 
 82-84 
 
 79-91 
 
 90-98 
 
 88-100 
 
 77-80 
 
 7,120 
 7,025 
 7,600 
 6,075 
 6.586 
 
 7,000-7,200 
 6,800-7,300 
 7,200-8,000 
 5,600-6,600 
 6,400-6,800 
 
 2,220 
 1,964 
 1,403 
 1,650 
 2.176 
 
 .18 
 .25 
 .08 
 .38 
 .60 
 
 3.962 
 1,870 
 3,850 
 2,902 
 
 Average 
 
 
 
 '85 
 
 6.881 
 
 
 1,883 
 
 .30 
 
126 Milk and Its Products. 
 
 These slight differences in individual bowls are 
 common to all of the different kinds of machines, so 
 far as is known, and this being the case, it is al- 
 ways due to the purchaser that he should secure from 
 the manufacturer a guarantee that any given ma- 
 chine will do work of a certain grade of ef&ciency. 
 
 Other desirable and undesirable features of a sepa- 
 rator .^Other things being equal, that separator is the 
 best which will skim clean at the lowest temperature 
 and with the least number of revolutions per min- 
 ute. Other details of construction being equally 
 good, and the capacities being the same, that separator 
 will run the easiest whose diameter is least. A ma- 
 chine of small diameter not only runs easier, but is 
 less easily thrown out of balance. The cream should 
 be delivered in a smooth stream of uniform density, 
 and the cream outlet should be of such form that 
 a heavy cream may pass through it without danger 
 of clogging. The bowl should be so constructed that 
 all parts may be readily reached with the hand and 
 thoroughly and easily cleaned. 
 
CHAPTER VII. 
 
 TBE RIPENING OF CREAM. 
 
 By the ripening process is meant all the treatment 
 which the cream receives from the time that it is sep- 
 arated from the milk until it is put into the churn. 
 Upon this treatment, and the changes that the cream 
 undergoes, very largely depend the quality of the butter 
 as regards texture and flavor. The texture of the 
 butter is very largely influenced by the changes of tem- 
 perature that are brought about during the ripening 
 process. It seems to be essential to the production of 
 a firm, solid texture in the butter that the cream, at 
 some time during the ripening process, should be sub- 
 jected to a constant temperature below 50° F. for sev- 
 eral hours. When cream has been separated by a 
 gravity process, particularly by a "deep setting" one, 
 it has already experienced the effects of such a tem- 
 perature, and is ready for ripening as soon as re- 
 moved from the milk. But when cream is separated 
 by a centrifug:al separator, the temperature as it comes 
 from the separator is rather high, and butter of good 
 texture cannot be made unless the cream is cooled 
 down and held cool for several hours before ripening 
 has far advanced. The first step, then, in the ripen- 
 ing process with separator cream is to reduce its 
 
 (127) 
 
128 Milk and Its Products. 
 
 temperature as rapidly and as uniformly as possible 
 to at least 50° F., and to hold it there for as long 
 a time as is convenient, usually six to eight hours. 
 Another point which influences the texture of the 
 butter depends upon the rapidity with which the vari- 
 ous changes of temperature are made, and the ex- 
 tremes of temperature that are used. That butter will 
 have the best texture which has seen the fewest pos- 
 sible changes of temperature between the time the milk 
 is drawn from the cow and the time it is churned, 
 and in which also all the necessary changes of tem- 
 perature have been made most gradually. Not only 
 will such butter have the best texture at low tem- 
 peratures, but it will stand the effects of high tem- 
 peratures better. In other words, it " stands up " 
 under the heat better than butter that during the pro- 
 cess of manufacture has been subject to sudden and 
 great changes of temperature, although the final result 
 may have been to keep it at a low temperature. 
 The effects of ripening are more important and more 
 marked upon the flavor of the butter than upon the 
 texture. It is during the ripening that the charac- 
 teristic flavors of the butter are largely brought out. 
 It is not necessary to the manufacture of the butter 
 itself that the cream be ripened at all. Butter may 
 be made from cream just as soon as it is separated 
 from the milk, but it will be of a distinctly different 
 quality from that made, from ripened cream. By 
 ripening in the ordinary sense is meant the produc- 
 tion of lactic acid in the cream. 
 
 In some attempts to substitute other acids for 
 
Origin of Butter Flavors. 129 
 
 lactic acid in ripening, Tiemann* found that in cream 
 to which a small amount of hydrochloric acid had 
 been added there was no difSculty in churning the 
 •butter, that the general flavor of the butter was 
 good, but that it lacked in aroma and had a some- 
 what oily texture. 
 
 There is some doubt as to the origin of the 
 characteristic flavors which are developed in the cream 
 during the ripening process. These flavors are un- 
 doubtedly due to the presence of certain volatile sub- 
 stances — fats, bacterial products, or ether-like com- 
 pounds — which are formed during the ripening pro- 
 cess. It was formerly supposed that the production 
 of the characteristic flavors was almost wholly a pro- 
 cess of oxidation, and that cream, in order to be prop- 
 erly ripened, and to develop the best flavors, must be 
 supplied with an abundance of oxygen in pure air 
 during the process. Our knowledge of the presence of 
 germs in milk and cream and the effect of their 
 growth upon the various constituents of the milk, has 
 led us to modify these views. At the present time it 
 seems probable that the growth of germs which pro- 
 duce lactic acid has much to do with the production 
 of the characteristic flavors of ripened cream. It has 
 been asserted by some, notably Conn, that the produc- 
 tion of the flavors is due to the growth of specific 
 flavor -producing germs that are largely independent of 
 the formation of lactic acid, but this view does not 
 seem to explain all of the phenomena of the appear- 
 
 *Milch Zeitung, xxiii p. 701. 
 I 
 
130 Milk and Its Products. 
 
 ance of such flavors, and it is by no means certain 
 that the flavors are not in part produced as the result 
 of direct oxidation. It is found in practice that the 
 regulation of the production of lactic acid is the 
 chief means in controlling the flavor. 
 
 The means of producing lactic acid. — In order that 
 the milk or cream should ripen, or become sour, it 
 is necessary that germs of lactic acid fermentations 
 should gain access to it, and that a temperature favor- 
 able to their normal development should be secured. 
 The presence of the germs may be left to chance 
 inoculation, or they may be artificially supplied. 
 Under ordinary conditions, by the time the cream has 
 been separated from the milk, there will have reached 
 it a sufficient number of germs of fermentation to 
 cause a rapid production of lactic acid, though the 
 number will vary from day to day and from time to 
 time, and a certain amount of acid cannot be de- 
 pended upon within any given specified time. " The 
 inoculation is more certain, and the desired degree 
 of acidity will be more surely reached, at the end_ 
 of a given time, if the germs are added in suffi- 
 cient quantity artificially. The source of the inocu- 
 lation may be buttermilk or cream from preceding 
 churnings, or it may be in the form of an artificially 
 prepared "starter" of sour skimmed milk, or it may 
 be in the form of any of the so-called commercial 
 lactic ferments. It is desirable that none but the 
 proper germs should find access to the milk, and 
 in relying upon natural means there is always more 
 or less danger that putrefactive and other undesirable 
 
Commercial Lactic Ferments. 131 
 
 ferments may gain access to the cream. As between 
 the various forms of artificial starter, there is not 
 much to be said. It is generally held that a starter 
 made from skimmed milk is less likely to contain 
 germs other than those desired than when cream, 
 whole milk, or even buttermilk are used. 
 
 With regard to the use of the various commer- 
 cial bacterial ferments, there is considerable diversity 
 of opinion. Their use was first recommended several 
 years ago in Denmark, as a result of the researches 
 of Storch, and has grown rapidly, both in Denmark 
 and Germany, until at the present time a large part 
 of the butter produced in the former country is made 
 from cream first pasteurized, and then ripened with 
 the aid of an artificial bacteria culture. The use 
 of such ferments has only slightly extended to this 
 country, chiefly through the medium of Hansen's 
 lactic ferment. 
 
 In this country Conn has been the chief investi- 
 gator of similar organisms. From 1890 to 1893* he 
 isolated s.aEfiral organisms, the culture of which in 
 cream improved the flavor of the resulting butter 
 to a greater or less extent. In the latter year he 
 discovered in' a can of milk sent from Uruguay to 
 the World's Columbian Exposition at Chicago, a 
 germ so much better in this respect that it alone 
 has since been used, and cultures of it placed upon 
 the market under the name of B.41 (Bacillus No. 41). 
 
 A series of investigations by Farrington and Rus- 
 
 *Storrs Aericultural Experiment Station, Eeports 1890-93. 
 
132 
 
 Milk and Its Products. 
 
 sell,* in which a large number of samples of butter 
 were made from cream ripened by the use of B. 41, 
 and in the ordinary way, or " normally," and sub- 
 mitted to the judgment of several experts who were 
 ignorant of the process of manufacture, led to tlie 
 conclusion that the "Conn culture, B. 41, did not 
 improve the flavor of the separator butter ripened 
 for one day at a high temperature, or of that ripened 
 for a longer time at a lower temperature ; on the 
 contrary, the score of the fresh B. 41 butter by 
 the different judges was, in the majority of cases, 
 materially lower than that of normal butter. * * * 
 With separator butter in cold storage, that made with 
 B. 41 deteriorated less than did the normal butter. 
 When taken from storage there was but little differ- 
 ence in flavor between these two butters, although 
 the normal butter when fresh scored higher." 
 
 The difference in the flavor of the two kinds of 
 butter when fresh, as indicated by the different 
 judges, is shown in the table: 
 
 
 Gurler. 
 
 Barber. 
 
 Moore. 
 
 General 
 average 
 scores. 
 
 Number of butter packages 
 scored - . 
 
 Average score of normal but- 
 ter .. . 
 
 Average score of B. 41 butter. 
 
 14 
 
 44.4 
 43.7 
 
 14 
 
 45.3 
 44 
 
 12 
 
 45.1 
 43 
 
 45.3 
 43.9 
 
 DifEerenoe in favor of normal 
 butter .... 
 
 .7 
 
 1.3 
 
 2.1 
 
 1.4 
 
 'Wisconsin Agricultural Experiment Station, Bulletin 48. 
 
Temperature of Ripening. 133 
 
 On the other hand, a considerable number of fac- 
 tories in this country have secured an increased flavor 
 and quality in their product from ripening their 
 cream with the aid of either Hansen's ferment or B. 41. 
 
 The present status of the whole matter seems 
 to be that the various commercial artificial ferments 
 are now prepared in such form that they are readily 
 transported, they retain their vitality for a consider- 
 able length of time, and are practically free from 
 any undesirable germs. Their use in careful hands 
 is likely to be followed with uniformly good results. 
 Still, where all of the surroundings are cleanly and 
 the atmosphere pure, the use of such artificial germs is 
 not necessary to produce butter of the highest quality. 
 
 Temperature of ripening. — The various germs of 
 lactic fermentations find their optimum growth point 
 at from 80° to 90° F., and milk or cream kept at those 
 temperatures will most rapidly become sour. The 
 effect of such high temperatures, while favorable to 
 the production of lactic acid, is less favorable to 
 the texture of the butter, and on this account it is 
 desirable to ripen the cream at as low a tempera- 
 ture as will insure a fairly rapid growth of the lactic 
 germs. A temperature of from 60° to 70° F. will 
 ordinarily bring this about. The amount of acid de- 
 veloped in any given length of time will depend not 
 only upon the temperature at which the cream has 
 been kept, but also upon the number and activity of 
 the germs originally present, so that if we have a 
 thorough inoculation to start with, a lower temper- 
 ature will be suificient to cause the development of 
 
134 Milk and Its Products. 
 
 the requisite amount of acid ; but if only a slight 
 inoculation is present, a higher temperature will be 
 necessary. Ordinarily, there will be more germs 
 present in the atmosphere during the warm months 
 than in the winter, consequently a lower temperature 
 will bring about the same degree of acidity in a 
 shorter time in summer than in winter. 
 
 The amount of acid necessary. — The amount of 
 acid that it is desirable to have in the cream at 
 the time of churning depends, of course, largely upon 
 the flavors desired by the consumer. It is important 
 that whatever amount is desired should be uniform 
 from day to day. By far the larger proportion of 
 consumers prefer the flavors that are characteristic of 
 ripening till sufRcient acid to slightly coagulate the 
 casein is present. Consumers of delicate taste 
 readily distinguish between the flavors due to a 
 greater or less amount of acid, and it is highly de- 
 sirable that some means of determining the amount 
 of acid present be available. The butter -maker of 
 trained senses has little difliculty in distinguishing by 
 the somewhat thickened and glistening appearance of 
 his cream, when stirred, the proper condition of the 
 cream for churning. Besides this, there are, fortunately, 
 more exact means for determining the acidity. 
 
 Acid tests. — Dr. A. G. Manns first suggested the 
 use of an alkali of known strength to determine the 
 proper acidity of cream for churning, and devised 
 what is known as Manns' acid test. It simply con- 
 sisted in neutralizing the acid in the cream with a 
 standard alkali, the standard used being that known 
 
Determination of Lactic Acid. 135 
 
 to chemists as decinormal, or ~,o~, and the acidity was 
 reckoned in terms of cubic centimeters of alkali re- 
 quired to neutralize the acid in a given quantitj' of 
 cream. In the use of this test, an indicator which 
 changes color according as the medium is ' acid or 
 alkaline, is used. A convenient indicator is phenol- 
 phthalein, which is colorless in acid solutions and 
 pinkish in alkaline. Later, Professor Farrington* 
 devised tablets containing a known amount of alkali 
 for the same purpose, known as Farrington's alkaline 
 tablets. Each tablet contains an amount of alkali 
 equal to 3.8 cubic centimeters of decinormal alkali, 
 and a sufficient amount of phenolphthalein indicator. 
 The cream to be tested is measured, and to it is 
 added a solution of the tablets (one tablet in ten 
 cubic centimeters of water) until the cream retains a 
 pinkish tinge. The tablet solution should always 
 be fresh, not more than ten hours old. The tab- 
 lets themselves will keep indefinitely. The proper 
 degree of acidity is in dictated when 30-35 c. c. of 
 Farrington tablet solution, or 11-13 c. c. of deci- 
 normal alkali, are required to neutralize the acid in 
 20 cubic centimeters of cream. 
 
 Determination of lactic acid in milk or cream. — Far- 
 rington's alkaline tablets may also be conveniently 
 used to determine the percentage of lactic acid in any 
 given sample of milk or cream. In order to do this, 
 it is only necessary to understand that equal volumes 
 of normal or decinormal acids and alkalies neutral- 
 
 *BuU. 32, ni. Agr. Exp. Sta. Bull. 52, Wis. Agr. Exp. Sta. 
 
'=^1 
 
 136 Milk and Its Products. 
 
 ize each other ; and, further, that a normal solu- 
 tion of lactic acid contains 90 grams of acid in 
 each liter, or 1,000 c. c. A decinormal solu- 
 tion would contain 1-lOth as much, or 9 grams 
 in each liter, and a cubic centimeter would con- 
 tain j;^oth as much as a liter, or .009 grams 
 of lactic acid. Each tablet of the Farrington 
 alkali is equal in strength to 3.8 c. c. of de- 
 cinormal alkali, and if the tablet solution is 
 made by dissolving 10 tablets in 100 e. c. of 
 water, each cubic centimeter of the solution will 
 be equal to .38 c. o. of decinormal alkali, and 
 will, therefore, neutralize .38 of .009 grams, or 
 .0034 grams, of lactic acid. 
 
 To determine the percentage of acid in any 
 given sample of milk or cream, any convenient 
 amount, as 20 c. c, of the sample to be tested 
 is measured out, and the tablet solution is ad- 
 ded from a burette or graduated cylin- 
 der till the milk retains a pinkish tinge. 
 If this occurs when 1 c. c. of the tablet 
 solution has been added, the 20 c. c. 
 
 Fig. 14. . . 
 
 B « of milk contam .0034 grams of lactic 
 
 rette. 
 
 acid; but 20 o. e. of milk weigh 20.64 
 grams (sp. gr. milk, 1.032), therefore the per- 
 centage of lactic acid is .0034-:-20.64=.00017, 
 or .017 per cent. If more than 1 c. c. of 
 the tablet solution is required to neutralize 
 the acid, or if more or less than 20 c. e. ^ 
 
 of milk or cream are taken, the percentage Grid u a- 
 of acid will be found by multiplying the cyuldCT' 
 
Further Effects of Bipening. 137 
 
 number of cubic centimeters of tablet solution re- 
 quired by .0034 and dividing by the number of 
 grams of milk taken (grams of milk=^e. c. X 1.032). 
 
 Further effects of ripening. — Besides affecting the 
 flavor, it is believed that ripening aids in the ease of 
 churning, iu the completeness of churning, and in 
 improving the keeping quality of the resulting butter. 
 It was formerly supposed that sweet cream could hot 
 be churned into, butter, and in fact with but a moder- 
 ate percentage of fat (15 to 20 per cent) it does 
 churn with much more difficulty than the same cream 
 after it has been ripened ; but since the introduction 
 of the separator, and the consequent production of 
 a much heavier cream, it has been found that sweet 
 cream can be churned into butter quite as readily 
 as ripened cream. In cream containing but a 
 moderate amount of fat, it is necessary to reduce the 
 temperature from six to eight degrees, in order to 
 churn it sweet. The difference in the keeping 
 quality of ripened and sweet cream butter is like- 
 wise not so great as it was formerly supposed to be. 
 In fact, sweet cream butter, if properly made and 
 kept, will in a short time very closely approach the 
 qualities of ripened cream butter. 
 
 Effects of churning cream of different degrees of 
 ripeness. — If parcels of cream of different degrees 
 of ripeness are mixed together and then churned, it 
 will be found that the different creams will churn 
 differently. One will produce butter in a shorter 
 time than another, or with less agitation. The con- 
 sequence is that when this occurs the churn is 
 
138 Milk and Its Products. 
 
 stopped before the churning is completed, and much 
 fat is lost in the buttermilk. It is a matter of 
 considerable practical importance, so far as loss of 
 fat is concerned, and to some extent also upon the 
 flavor of the butter, that all of the cream churned 
 at one time should be ripened together, evenly and 
 uniformly. If creams of different ages ai'e to be 
 churned together they should be mixed together at 
 least twelve hours before churning, so that the con- 
 dition of acidity shall be the same throughout the 
 whole mass. 
 
 Bad effects of over -ripening. — When too much lactic 
 acid is developed in the cream the casein is firmly 
 coagulated, and in the process of churning is broken 
 up into minute granules, which become incorpo- 
 rated into the butter in the form of white specks or 
 flakes of casein. Such white specks, besides injur- 
 ing the appearance of the butter, greatly detract 
 from its keeping qualities, as the putrefactive fer- 
 mentations soon set up in them and give rise to 
 disagreeable flavors. Danger from this source is 
 liable to be present if the coagulation of the cream 
 has gone so far that any whey has separated. The 
 cream should in all cases be churned before the ripen- 
 ing process has reached this point. It was formerly 
 supposed, and is still generally believed, that the pro- 
 duction of an excess of. lactic acid in ripening tends 
 to a loss of butter, from the fact that the acid 
 dissolved or "cut" the fat, causing it to disappear. 
 This has been shown, both theoretically and practi- 
 cally, not to be the case. Lactic acid has no appre- 
 
Effects of Over -Ripening. 139 
 
 ciable effect upon fat, so far as dissolving or decom- 
 posing it is concerned, and cream may be held until 
 the whey has separated to the full extent without 
 any loss in the amount of butter that it is possible 
 to churn from it. The chief evil effect in over- 
 ripening is in the production of strong and undesir- 
 able flavors accompanying the undue production of 
 lactic acid. 
 
CHAPTER VIII. 
 
 CHUBNINQ. 
 
 The process of causing the particles of butter fat 
 to unite into masses, so that they may readily be 
 separated from the milk serum, is called churning. 
 Such union of the particles of fat is ordinarily 
 brought about by agitation of the cream in a suit- 
 able vessel, called a chum. If milk or cream be 
 agitated at a temperature somewhat below the melt- 
 ing point of butter fat, the particles of fat, as they 
 pass by one another, agglutinate themselves into 
 masses, and, the process being continued, the fii'st 
 formed masses continue uniting, until finally the 
 whole body of fat may be brought together in a prac- 
 tically solid mass. The conditions influencing the 
 separation of fat in this way are, first, the viscosity 
 of the milk ; second, the ripeness of the cream ; ' 
 third, the temperature; fourth, the nature of the 
 agitation; fifth, the quality of the globules of fat. 
 
 The viscosity of the milk. — The viscosity of the 
 milk affects the churning, in that it tends to keep 
 the particles of fat from moving freely upon one 
 another, and in that the viscous portions of the 
 milk, notably some of the albuminous matter, form a 
 more or less dense layer about the fat globules. 
 
 (140) 
 
Temperature of Churning. 141 
 
 tending to keep them apart. The more viscous the 
 milk, then, the greater the difficulty with which it 
 will churn. 
 
 The ripeness of the cream. — The ripeness of the 
 cream affects the churning, largely because of its 
 effect upon the viscosity of the milk. The produc- 
 tion of lactic acid in milk always has the tendency 
 to render it less viscous, and sour milk or cream, 
 therefore, will churn more readily than sweet for 
 this reason. The viscosity of the milk must be 
 distinguished from the thickness of the milk, due 
 to the coagulation of the casein. Souring of the 
 milk renders it less viscous, but at the same time 
 by coagulating the casein renders it thicker and 
 less fluid. 
 
 The temperature. — The temperature is the most im- 
 portant condition affecting churning. Whether the 
 particles of fat shall unite as they pass by one 
 another when the liquid is in motion, depends very 
 largely itpon their temperature and degree of plas- 
 ticity. If the temperature is too low, the globules 
 of fat are so hard that when they hit one another 
 they do not stick together. If, on the other hand, 
 the temperature is too high, the effect of agita- 
 ting the globules of fat is, instead of causing them 
 to unite, to break them up into still smaller glob- 
 ules, and so render the emulsion more permanent. 
 The range of temperature through which the parti- 
 cles of fat may be made to unite is considerable. 
 The extreme limits may be placed at from 46° to 
 80° F. But while butter may be churned from 
 
142 Milk and Its Products. 
 
 milk or cream through this wide range of tempera- 
 ture, the quality of the butter is very seriously af- 
 fected. The butter is in the best condition when it 
 is churned at such a temperature that the particles 
 of fat unite readily, and when united form firm 
 masses or granules of butter. The temperature at 
 which this desirable end is brought about varies 
 under a wide range of conditions, the most impor- 
 tant of which are the following: The individuality of 
 the animal ; the period of lactation ; the nature of 
 the food of the cows ; the season of the yeai*. 
 These conditions are all conditions which affect the 
 melting point of the butter fat. The higher the 
 melting point of the fat, the higher the tempera- 
 ture at which the milk should be churned, and the 
 lower the melting point of the fat, the lower the 
 churning temperature. Any condition which tends 
 to make the butter fat hard will necessarily be fol- 
 lowed by a rise in the churning temperature, and 
 any condition which tends to make the butter fat 
 soft will for the same reason be followed by a 
 fall in the churning temperature. It is impossible, 
 then, to name any single temperature which is the 
 best or even the proper one at which to churn ; 
 but while there is a considerable range of tempera- 
 ture, which under different conditions may give the 
 best results, still this range is not so wide as the 
 range of temperature at which it is possible to 
 churn, and the limits may perhaps be placed at from 
 50° to 66° F. In general, the lowest temperature 
 compatible with securing butter in a reasonable 
 
The Nature of the Agitation. 143 
 
 length of time will give butter of the best quality. 
 The lower the temperature at which the butter is 
 churned, other things being equal, the more com- 
 pletely will the butter be removed from the butter- 
 milk, the longer will be the time required for churn- 
 ing, and the less casein will be found in the butter. 
 The nature of the agitation. — It is generally be- 
 lieved that the best results follow from agitating 
 the cream in such a way that the particles of fat 
 are subject to more or less concussion, though it 
 is not at all necessary that this concussion should 
 take place. Mere gentle stirring of the cream, if 
 continued long enough, will bring butter, and agi- 
 tating the cream by passing bubbles of air through 
 it will also cause it to churn. Many churns have 
 been devised which bring about the churning by 
 agitating the cream with floats or paddles, and in 
 the old-fashioned dash churn there was a minimum 
 amount of concussion, the motion beiiig largely that 
 of stirring. Where the agitation is brought about 
 by the use of paddles or stirring instruments, the 
 texture of the butter is usually injured, because of 
 the effect of the stirring motion upon the grain of 
 the first particles of butter formed. The best churns, 
 then, are entirely hollow vessels, barrel or box, 
 which bring about agitation of the cream through 
 concussion of the particles upon the sides of the 
 rotating churn. The churning depends, also, upon 
 the rate of agitation; the faster the motion to 
 which the particles of cream are subjected, the 
 quicker will be the churning. In this respect the 
 
144 
 
 Milk and Itx Products. 
 
 motion of the particles and the motion of the churn 
 must not he confounded. If the motion of the churn 
 is increased so that sufficient centrifugal force is gen- 
 erated to cause the particles of cream to partake of 
 
 V\i^. M\. Bni-rfl pnwov ohiini. 
 
 the motion of the churn, tlicn, though the particles 
 may jiass through S]ia<'c at a gn-atcr rate of speed, 
 the motion of the particles upon ca<'h other will be 
 lessened. A maximum motion of the particles upon 
 each other is obtained when the speed of the chui'n 
 stops just short of setting up centrifugal force in 
 
Size and Character of Fat Globul 
 
 145 
 
 the churn. This will be found to correspond to a 
 motion of the particles of cream of about 700 feet per 
 minute . 
 
 The (pmlity of the glotmles of f(it.—llh.fi quality of 
 the globules of fat, both as to their size and char- 
 
 Fig. 17. Square hox power eliiirn. 
 
 aeter, bears an important part in the phenomena 
 of churning'. 8o far as the hardness or softness of 
 the fats are concerned, this has already been treated 
 of under the effect of temperature; Init temperature 
 is not the only influence which causes variation 'va, 
 J 
 
146 
 
 Milk and Its Products. 
 
 Fig. 18. "Simplex" combined 
 cliiirn and butter worker. 
 
 the hardness or softness of the fat. The relative 
 proportions of hard and soft fats vary consider 
 ably. When the soft fats 
 predominate, the churning is 
 easier than when they are in 
 less proportion, while an un- 
 due proportion of hard fats 
 often renders churning ex- 
 tremely dif&cult. The size of 
 the fat globules also bears an 
 important part in the ease 
 and time requii-ed for churn- 
 ing. In passing through a 
 mass of liquid two large globules are more likely 
 to hit each other than are two small ones, the rela- 
 tive probability of their meeting and hitting being 
 in proportion to the squares of their diameters. 
 
 The end of churning. — When the particles of fat 
 have united to such an extent that they begin to be 
 visible in the cream, the butter is said to "break," 
 and from this time on the process of churning is rap- 
 idly finished. Two things are to be observed in bring- 
 ing the operation of churning to a close. In the 
 first place, the churning should be continued until 
 the separation of fat is as complete as possible. 
 In the second place, the larger the masses of but- 
 ter in the churning the more difficult is the re- 
 moval of the buttermilk. If the cream is thor- 
 oughly and uniformly ripened, the separation will be 
 more uniform and the churning more complete 
 than when creams of different degrees of ripeness 
 
Conditions of Difficult Churning. 147 
 
 are churned together ; but under various conditions, 
 and from time to time, the completeness of separation 
 varies with the size of the granules of butter; that 
 is to say, if the granules have reached a certain size, 
 it does not always follow that the fat has been re- 
 moved from the buttermilk to the same degree, so 
 that the size of the granules of butter is not a certain 
 indication of the completeness of churning. When the 
 churning process is complete, the buttermilk takes on 
 a thin, bluish, watery appearance, quite distinct from 
 the thicker creamy appearance of the unchurned cream, 
 and the churning should be continued until this con- 
 dition of the buttermilk is reached, even though the 
 granules are increased in size beyond the point favor- 
 able to their best separation from the buttermilk. 
 The higher the temperature at which the cream is 
 churned, the greater the percentage of fat left in 
 the buttermilk and the more casein will be incorpo- 
 rated with the butter. 
 
 Difficult churning. — Conditions often arise under 
 which it is very difficult or impossible to cause the 
 butter to unite in granules and separate from the but- 
 termilk. One of the chief difficulties accompanies 
 a small and hard condition- of the butter granules 
 with a high viscosity in the cream. These con- 
 ditions usually occur in the late fall and early win- 
 ter months, when the cows are far advanced in lac- 
 tation, and when they are often fed on dry food 
 of a character to make hard butter fat. An im- 
 proper ripening of the cream often accompanies 
 these conditions, so that complaints of difficulty in 
 
' 148 Milk and Its Products. 
 
 churning are usually numerous at this period of 
 the year. These complaints readily yield to the 
 proper treatment, which is indicated under the con- 
 ditions affecting churning, and so far as is known 
 there never occurs a condition under which it is 
 absolutely impossible to churn the butter from any 
 given sample of cream. The course to be followed in 
 cases of this nature is, first, to add to the food of 
 the cows something of a succulent nature, that will 
 cause the secretion of milk to be greater in amount 
 and not so viscous. Second, to further lessen the 
 viscosity by bringing about a vigorous lactic acid 
 fermentation in the milk, and in extreme instances, 
 perhaps, diluting the cream with warm water or 
 weak brine. Care must be taken that this dilution 
 does not go too far, or difficulty in churning from 
 the thinness of the cream will result. The produc- 
 tion of lactic acid in good amounts and within a 
 reasonable time seems to be an injportant means of 
 overcoming these cases of difficult churning. It is 
 not unlikely that some of the lower fermentations, 
 which take place at temperatures below which the 
 lactic acid germs are active, may in themselves have 
 a retarding effect upon the churning. These cases 
 of difficult churning are frequently accompanied by 
 the production of an acrid or bitter putrefactive 
 fermentation product in the cream. 
 
 If the attempt is made to churn at an extremely 
 low temperature, the agitation of the cream serves 
 to incorporate with it bubbles of air, and the 
 cream froths or swells. When this takes place, 
 
Helping Butter to '^ Break." 149 
 
 little can be done except to allow the cream to 
 stand for several hours and then warm it up 
 gradually four or five degrees before -again starting 
 the churn. There is very much less danger of swel- 
 ling in the revolving churns than in dash churns. 
 
 Frequently also, in eases when the attempt is 
 made to churn at the extreme lowest point possible, 
 the formation of butter stops just short of the 
 breaking point, and further agitation does not resuit 
 in an increase of butter. This may be overcome by 
 slightly raising the temperature, or by the addition 
 of a little water at a temperature of 85° or 90° F.; 
 or, what is better, it can usually be brought about 
 by the addition of a little dry salt to the churn. 
 The solution of salt in the water of the cream 
 seems to affect the viscosity in such a way that 
 the formation of butter granules is greatly facilitated. 
 
 When ripened cream is churned, there is usually 
 an evolution of gas immediately after the agitation 
 commences. This is gas which has been formed by 
 some of the fermentations going on in the cream, and 
 the gas is liberated within the first five or ten min- 
 utes. The temperature also rises two or three degrees 
 during the operation, from the effect of the friction 
 of the particles upon one another. 
 
CHAPTER IX. 
 
 FINISHING AND MARKETING BUTTER. 
 
 When the churning process is complete, it still 
 remains to separate the buttermilk from the granules 
 of butter, and to bring the whole into a solid, uni- 
 form mass, suitable for consumption and properly 
 flavored with salt. These operations may be per- 
 formed in a variety of ways. Formerly it was the 
 custom to continue the churning until the butter 
 was in a measurably solid mass, when it was re- 
 moved from the churn and the buttermilk expelled 
 by pressure, at the same time that the salt was 
 incorporated with the butter. Now the buttermilk 
 is uniformly removed from the butter by washing 
 with water in the churn, and in many instances 
 the salt is incorporated with it during the whole 
 or part of this operation ; but the more common 
 practice is to wash the butter in the churn and to 
 work out the surplus moisture and incorporate the 
 salt upon a separate instrument, called a butter 
 worker. 
 
 Washing the butter. — The churning should be 
 stopped as soon as the buttermilk is clear and wa- 
 tery. If the churning has been done at the right 
 temperature and the cream properly ripened, this con- 
 
 (150) 
 
Washing Butter. 151 
 
 dition will occur when the butter granules are not 
 larger than kernels of wheat. As soon as the churn 
 is stopped, the addition of a little cold water to the 
 contents of the churn will facilitate the rising of 
 the smaller globules of butter through the butter- 
 milk. The buttermilk should then be drawn off 
 from the bottom of the churn, and the butter al- 
 lowed to drain thoroughly. After the butter is thor- 
 oughly drained, water at a temperature of 45° to 
 55° F. should be added in amounts equal to two- 
 thirds the amount of buttermilk withdrawn. The 
 contents of the churn should then be gently agitated, 
 so that the water may come in contact with each par- 
 ticle of butter, but not to such an extent that the 
 particles will compact themselves into larger masses. 
 In about ten or fifteen minutes, this water should be 
 withdrawn and the butter allowed to drain as Before, 
 after which the butter should be washed the second 
 time in the same manner. This second water should 
 run away clear, or with a very slight milkiness. 
 If it is at all milky, the butter should be washed 
 again, and the washing continued until the water does 
 run av/ay clear. It is desirable that as little wash- 
 ing be done as possible, and if care is taken in 
 stopping the churning at the right moment, and in 
 draining and washing the butter, two waters will be 
 sufficient. The addition of a small amount of salt 
 to the first washing water will facilitate the removal 
 of the buttermilk, but will not add any perceptible 
 saltiness to the butter. The way in which the wash- 
 ing is done perceptibly affects the quality of the 
 
152 Milk and Its Products 
 
 finished butter, particularly so far as regards its tex- 
 ture and percentage of water. The smaller the 
 granules of butter when the churn is stopped, and 
 the colder the water used, the more water will re- 
 main in the butter without appearing in the form 
 of drops. If the churning has progressed until the 
 butter has formed masses the size of a hickory nut 
 or larger, particularly if the butter is soft, it will 
 be impossible to completely wash the buttermilk from 
 the butter, and the buttermilk must necessarily be 
 removed in working. Such butter will always re- 
 tain in its flavor traces of the buttermilk so incor- 
 porated with it. 
 
 The texture of the butter is also affected by the 
 temperature of the wash water. If the butter eomes 
 soft, the attempt is usually made to cool it down 
 rapidly by the addition of large amounts of very cold 
 water. The butter can be hardened up in this way, 
 but it will show the effect of sudden changes of 
 temperature afterward much more strongly than if it 
 were cooled down more slowlJ^ Butter fat does 
 not conduct heat rapidly, and to become thoroughly 
 warm or thoroughly cool requires some little time. 
 If, then, butter has been churned too warm, and 
 comes in a soft condition, the washing process should 
 be much prolonged. Use the ordinary amount of 
 water and at the ordinary temperature, but allow the 
 butter to remain in it until it has had sufiicient time 
 to thoroughly adjust itself to the changed condition. 
 It can then be taken out and worked without dan- 
 ger of quickly becoming soft again. There is also 
 
Working Butter. 
 
 153 
 
 danger of removing some of the more delicate flavor- 
 ing oils of the butter by the use of too large an 
 amount of very cold water. These flavoring oils are 
 
 Fig, 19. "Eureka" hand butter-worker. 
 
 slightly soluble, and more soluble at a low tempera- 
 ture, so that the drenching with large amounts of 
 very cold water has a tendency toward the produc- 
 tion of a flavorless oi- tallowy butter. 
 
 Working. — Working butter is an integral part of 
 the process of manufacture, only in so far as it re- 
 lates to the incorporation of the salt and bringing 
 the butter into the compact form necessary for con- 
 sumption, so that all working beyond that which 
 is necessary to bring about these two things is super- 
 
]E4 
 
 Milk and Its ProdurAs 
 
 fluous, and, because of the danger of injuring the 
 grain of the butter, is objectionable. The grain 
 of the butter is least affected by working when this 
 is done by pressure and at a temperature of from 
 45° to 55° F. The amount of water that remains 
 
 Fig. 20. "Mason" table butter-worker. 
 
 in the butter depends, as before stated, upon the 
 temperature and fineness of the granules. The finer 
 and colder the butter, the more water will it retain. 
 Salting. — Salt is added to butter solely for the 
 sake of the flavor which it imparts. While salt has 
 undoubted antiseptic properties, these play very little 
 part in the preservation of butter, and need not be 
 taken into consideration. The amount of salt, then, 
 that should be added to butter depends entirely 
 
Salting Butter. 
 
 155 
 
 upon the taste of the consumer for whom it is in- 
 tended, and may vary from a mere trifle to as 
 nnieh as 2/2 oiinces for each pound of butter. 
 The great majority of consumers, however, prefer 
 an amount ranging between % of an ounce and 1 
 ounce to the pound. The addition of a uniform 
 
 ' Centrifugal 
 
 amount of salt from day to day is a matter of 
 considerable importance in securing a uniform qual- 
 ity of butter, and the amount of salt should, there- 
 fore, be based upon the least vai-iable factor possi- 
 ble. It will be found that from day to day the 
 size of the granules of butter when washed, and the 
 
156 Milh and Its Products. 
 
 amount of water adhering to them, will vary consid- 
 erably, so that the weight of washed and drained but- 
 ter will not bear any definite relation to the amount 
 of finished butter, and if the attempt is made to gauge 
 the salt by the weight of drained butter, it will be 
 found that the ■ degree of saltness will vary considera- 
 bly, because when more watM- is contained in the 
 butter much more of the ■ salt will pass out with 
 the brine. When a separator is used in creaming, 
 the weight of cream will be found to bear a closer 
 proportion to the weight of finished butter than 
 either the original weight of the whole milk or th« 
 weight of the washed and drained butter, and the 
 more uniform salting will be obtained if the salt 
 is added in the ratio of a certain percentage of 
 the weight of the cream. The salt should be added 
 so that it can be readily and uniformly incorporated 
 with the whole amount of butter. This is con- 
 veniently done while the water is being expressed 
 from the butter in the worker, and the working 
 should continue until the salt has completely dis- 
 solved, because the salt has a deepening effect upon 
 the color of the butter, and if some undissolved 
 portions remain, these; afterwards dissolving in the 
 water • contained in the butter, will make a strong 
 brine at that particular point, and consequently a 
 deeper color, and mottled or streaked butter is the 
 result. 
 
 The salt should be dry, of uniform grain, and 
 should readily and completely dissolve to a clear 
 solution. Those brands of salt which are made from 
 
Packing Butter. 157 
 
 the natural crystal give the best results so far as re- 
 maining dry and freedom from caking are concerned. 
 
 Brine salting. — With many who prefer a butter 
 slightly salted, it is sometimes convenient to add 
 the salt through the medium of brine, rather than 
 to mix it with the butter in a dry condition. The 
 advantages of brine salting are that a light amount 
 of salt may be uniformly incorporated with the 
 butter. It is not possible to incorporate with the 
 butter a large amount of salt in this way. Where 
 well -drained butter is salted at the rate of one 
 ounce to the pound, there will remain in the but- 
 ter about 3 per cent of salt. Where butter is 
 washed twice with a saturated brine, there will re- 
 main in the butter when worked about 2 per cent 
 of salt. In salting butter in this manner, it is nec- 
 essary that the brine should be prepared before- 
 hand. This is best done by dissolving the salt in 
 warm water, as much as the water will hold, and 
 then cooling it to the proper temperature to add to 
 the butter. The brine in this instance may take the 
 place of the second wash water. After the brine 
 has remained upon the butter five or ten minutes, 
 it should be withdrawn and additional salt added to 
 it, or a second portion of saturated brine added and 
 left upon the butter for a similar length of time, 
 after which the brine may be withdrawn and the 
 butter worked in the ordinary manner. 
 
 Packing and marketing. — After the butter has 
 been worked until the salt is completely dissolved 
 and a sufficient amount of water removed, it is 
 
158 Milk and Its Products. 
 
 ready for packing. Butter that is to be packed 
 and held for any considerable length of time should 
 be worked drier than when it is intended for im- 
 mediate consumption. Fresh butter is most highly 
 esteemed in most mai-kets when it contains about all 
 the water that it will hold, but if such butter is 
 held for any length of time the evaporation of water 
 from the surface will lead to a deposition of salt, 
 which detracts much from its appearance and sala- 
 bleness. An ideal package for butter is one that is 
 light, strong and tight. None of the packages 
 in ordinary use are perfect in all of these respects. 
 Wooden packages, though light and strong, always 
 leak more or less and let in air. Tin packages 
 are more or less objectionable because of the action 
 of the salt upon the tin, and iron, and glass, and 
 crockery packages, although tight and clean, are 
 heavy and subject to breakage. Packages made of 
 paper or wood pulp have been used to some extent, as 
 have also packages of these materials covered with 
 paraffine, but they do not make a very attractive 
 package. All things considered, tight, smooth, well- 
 made tubs of ash, spruce or oak make the most 
 available package. All wooden packages possess the 
 characteristic flavor of the wood, which may be im- 
 parted to the butter to a greater or less extent if 
 it is allowed to remain in them very long. In 
 order to obviate this, the odor of the wood should be 
 removed as much as possible before the butter is 
 packed. The package should be thoroughly steamed, 
 and then filled with hot water in which some salt 
 
Composition of Butter. 159 
 
 has been dissolved, and allowed to stand at least 
 twenty -four hours, after which it should be scalded 
 a second time and then cooled with cold water. 
 Butter may also be packed in prints or moulds, 
 especially for immediate consumption. The demand 
 for butter in this form is increasing, and for nearby 
 markets it is one of the most desirable forms of 
 packing. In cool weather and with proper precau- 
 tions, prints may also be shipped considerable dis- 
 tances with success. Prints are usually made in 
 pound and half-pound sizes, intended to go directly 
 upon the table in the shape in which they leave 
 the manufacturer. Various shapes and sizes of prints 
 have been made, but since the great increase in the 
 demand for butter in this shape, a standard size for 
 pound prints has been settled upon that makes a 
 rectangular print, 4% x 2% x 2% inches. These 
 prints are wrapped in parchment paper and packed 
 in specially made carrying boxes. 
 
 Composition and quality of butter. — The average 
 composition of butter is about as follows: 
 
 Fat . ... ■ . 85 per cent. 
 
 Casein . . 1 per cent. 
 
 Salt .... 3 per cent. 
 
 Water . . . 11 per cent. 
 
 The percentage of fat should not fall below 80 per 
 cent nor the water rise above 15 per cent. The per- 
 centage of casein should not exceed 4 per cent. The 
 percentage of fat in butter of good quality often rises 
 to 86 or 88 per cent. The quality of butter is 
 Judged upon its flavor, texture, color, amount of salt, 
 
160 Milk and Its Products. 
 
 and its general style and appearance. Butter of good 
 flavor should have the characteristic flavors well pro- 
 nounced. It should be free from any rancidity, and 
 clean and pure so far as any extraneous flavor is con- 
 cerned. The determination of the flavor of any sam- 
 ple of butter is entirely one of individual judgment. 
 To some a high flavor is one in which the flavoring 
 oils are developed almost to the verge of rancidity; 
 in others, high flavor means a certain amount of the 
 flavor of sour milk or buttermilk ; with still others, 
 that butter is esteemed of the best flavor that is 
 cleanest and purest. The true bouquet of high -class 
 butter is a mild, distinct, volatile flavor or combina- 
 tion of flavors extremely difflcult to describe, and only 
 met with in perfection under the best conditions. 
 
 The texture of butter depends upon the state of 
 the granular condition of the fats. When the butter 
 is flrst formed in the churn it makes its appearance 
 in the shape of minute irregular granules. In the sub- 
 sequent process of manufacture these granules never 
 completely lose their individuality, and constitute the 
 so-called grain of the butter. The more distinctly 
 the individuality of the granules is marked in the 
 mass, of butter, the better the texture. The texture 
 of the butter is shown by an appearance like broken 
 cast iron when a mass of butter is broken in two 
 transversely, and when a metal is passed through the 
 butter, as a knife or trier, if the butter be of the 
 best texture, no particles of fat adhere to it. The 
 texture of the butter is deteriorated if the particles 
 of butter are churned iu too large masses, and if 
 
Judging Butter. 161 
 
 in the process of working the individual particles 
 are made to move upon one another at too high a 
 temperature. The mere warming of the butter to a 
 point approaching the melting point destroys the 
 grain upon subsequent cooling, even though the mass 
 of butter may have been undisturbed. 
 
 The color of the butter should be a clear, bright, 
 golden yellow, such as is naturally yielded by the 
 cow when feeding upon fresh pasture grasses. The 
 natural color of the butter is affected very largely by 
 the race of the cow, by the character of the food, 
 and by the period of lactation. Scarcely any breed 
 of cows will yield a butter of ideal color upon dry 
 food late in their period of lactation." On the other 
 hand, one or two races upon fresh pasture will 
 yield a butter of too high a color to suit the most 
 critical trade. The great mass of butter made is 
 artificially colored. For this purpose a large va- 
 riety .of substances has been used, but the color- 
 ing matter most commonly employed is a prep- 
 aration of annatto (a coloring matter in the seed 
 pulp of Bixa orellann) in some neutral oil. This 
 coloring matter is prepared of such strength that only 
 minute quantities are necessary to be added to the 
 cream to produce butter of the proper shade. Ani- 
 line colors are also quite largely used in the prep- 
 aration of butter colors. They are cheaper and do 
 not so easily fade as annatto, and some of them 
 are harmless ; but because of the liability of their 
 containing injurious or poisonous substances their 
 use is not to be recommended. Butter artificially 
 
162 Milk and Its Products. 
 
 colored should be uniform, of a bright golden 
 yellow color, free from any reddish tinge. The 
 demand of different markets varies considerably in 
 regard to the shade of color desired. 
 
 In regard to salt, the quality of the butter is 
 not necessarily affected by the amount of salt, that 
 being established by the demand of the trade for 
 which it is intended, but the salt, in whatever de- 
 gree added, should be completely dissolved, and 
 should be uniform throughout the whole mass of 
 butter. The finish of the butter, in whatever form 
 packed, should be such that it will present a neat, 
 clean, attractive appearance. The different qualities 
 of butter are ranked in importance in accordance 
 with the following scales : 
 
 Flavor 40 to 45. 
 
 Texture 25 to .30. 
 
 Color 10 to 15. 
 
 Salt .10 
 
 Finish 5 
 
CHAPTER X. 
 
 MILK FOR CHEESE MAKING. 
 
 Cheese is a product manufactured from milk, into 
 which a large part of the solids are gathered together 
 in such form that their nourishing qualities are re- 
 tained, at the same time that they are brought into 
 a condition capable of preservation and convenient 
 for transportation. The solids which are concerned 
 in the manufacture of cheese are the casein, the fats, 
 and a considerable portion of the ash. The albumin, 
 nearly all of the sugar, about one -third of the ash, 
 and a small part of the fat, escape during the course 
 of manufacture. The elimination of a large part of 
 the water is the chief step in the process of cheese 
 making. In general terms, cheese consists of about 
 equal proportions of water, fat and casein, with a 
 certain amount of salt and minute quantities of milk 
 sugar and ash. In milk, the casein exists in a state 
 of minute suspension or semi-solution. The essential 
 step in securing the separation of the water is in 
 rendering the casein insoluble. Casein, like most 
 albuminous organic substances, exists in two forms, 
 known respectively as the soluble and the insoluble 
 or coagulated form, and the change from solution to 
 insolubility is termed coagulation. In the case of 
 
 (163) 
 
164 Milk and Its Products. 
 
 casein, coagtilation may be brought about by several 
 reagents, but the one universally employed in cheese 
 making is a soluble ferment found in the stomachs 
 of young mammalia and in certain other animals, 
 known as rennet. By the addition of rennet to 
 milk, the casein takes on the form of a homogene- 
 ous gelatinous solid, and in changing its form en- 
 closes in its mass the globules of fat. In bringing 
 about the change in the casein in this way, the ren- 
 net acts by contact ; that is, its own constitution is 
 in no way disturbed, and a minute amount of rennet 
 is capable of causing the coagulation of a large 
 amount of milk. 
 
 Quality of milk for cheese making. — While it is 
 scarcely necessary to demonstrate that milk is val- 
 uable for butter making in proportion to the amount 
 of fat it contains, the proposition that its percent- 
 age of fat is also a measure of the value of nearly 
 all milk for cheese making has not been so readily 
 accepted. Indeed, until within a very short time, the 
 prevailing opinion among dairymen and cheese -makers 
 has been that a milk poor in fat was likely to be 
 rich in casein, and hence more valuable for cheese 
 making purposes. But both fat and casein are con- 
 stituents of cheese, and both are of nearly equal im- 
 portance ; hence, the richer a milk is in fat, the 
 more cheese it will make, and recent research has 
 shown that for milks containing a normal amount of 
 fat the yield of cheese will be nearly proportional to 
 the percentage of fat in the milk. 
 
Relation of Fat to (jasein. 
 
 165 
 
 Van Slyke,*.in a series of investigations extend- 
 ing over several years, and including the milk of not 
 less than fifteen hundred different cows, found that as 
 the percentage of fat increased the percentage of 
 casein increased in a nearly constant ratio ; or, to 
 quote his own words : "While we have noticed con- 
 siderable variation when we considered individual 
 herds, We have found that, as a rule, there were two- 
 thirds of one pound of casein for each pound of 
 fat in the milk, whether the milk contained 3 or 4 
 per cent of fat ; though this normal relation was con- 
 siderably affected in the season of 1893 by the effects 
 of drought upon the pastures. * * * * When 
 the amount of fat in the milk increased beyond 4% 
 per cent, there was a gradual but slight diminution 
 of casein for each pound of fat." 
 
 The accompanying tables give the data upon which 
 Dr. Van Slyke's opinions were based : 
 
 Table shoioing 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. 
 
 I. 
 
 3 to 3.5 
 
 22 
 
 3.35 
 
 ■2.20 
 
 0.66 
 
 II. . 
 
 3.5 to 4 
 
 112 
 
 3.72 
 
 2.46 
 
 0.66 
 
 III. 
 
 4 to 4.5 
 
 78 
 
 4.15 
 
 2.70 
 
 0.65 
 
 IV. 
 
 4.5 to 5 
 
 16 
 
 4.74 
 
 3.05 
 
 0.64 
 
 V. 
 
 5 to 5.25 
 
 7 
 
 5.13 
 
 3.12 
 
 0.61 
 
 *New York Agricultural Experiment Station, Bulletin, No. 68, New Series. 
 
166 
 
 Milk and Its Products. 
 
 Table showing relation 
 
 of fat in milk to yield of cheese. 
 
 Group. 
 
 Per cent of fat in 
 milk. 
 
 Pounds of green 
 
 cheese made from 100 
 
 lbs. of milk. 
 
 Pounds of green 
 cheese made for one 
 pound of fat in milk. 
 
 I. 
 II. 
 III. 
 
 IV. 
 V. 
 
 3 to 3.5 
 3.5 to 4 
 
 4 to 4.5 
 4.5 to 5 
 
 5 to 5 25 
 
 9.14 
 10.04 
 11.34 
 12,85 
 13.62 
 
 2.73 
 2.70 
 2.73 
 2.71 
 2.66 
 
 Babcock* tabulated the results of a large num- 
 ber of observations in factories in Wisconsin in the 
 accompanying tables, and while agreeing in the main 
 with Van Slyke, was forced to conclude that, " at the 
 same season of the year, rich milks do not yield as 
 much cheese in proportion to the fat they contain as 
 do poor milks, but that a rich milk toward the end of 
 the season may do as well as a much poorer milk 
 earlier in the season." 
 
 Table showing yield of cheese in Wisconsin factories according to 
 per cent of fat in milk. 
 
 No. of 
 groups. 
 
 No. of 
 reports. 
 
 Range of fat 
 per cent. 
 
 Average per 
 cent of fat. 
 
 Average 
 
 yield of 
 
 cheese per 
 
 100 lbs. milk. 
 
 Lbs. of cured 
 cheese for 
 1 lb. fat. 
 
 1 
 2 
 3 
 4 
 5 
 6 
 
 24 
 90 
 134 
 43 
 46 
 '20 
 
 under 3.25 
 3.25—3.50 
 3.50—3.75 
 3.75-4.00 
 4.00-4.25 
 over 4.25 
 
 3.126 
 3.382 
 3.600 
 3.839 
 4.090 
 4.447 
 
 9.194 
 9.285 
 9.407 
 9.806 
 10.300 
 10.707 
 
 2.941 
 2.730 
 2.613 
 2.562 
 2.512 
 2.407 
 
 All groups. . 
 
 347 
 
 
 3.64 
 
 9.666 
 
 2.628 
 
 •Wisconsin Aericultural Experiment Station, 11th Annual Report, p. 137. 
 
Relation of Fat to Casein. 167 
 
 Table showing yield of cheese in Wisconsin factories hy months. 
 
 Month. 
 
 No. of 
 reports. 
 
 Avei'age per 
 cent of fat. 
 
 Average 
 
 yield of 
 
 cheese per 
 
 100 lbs. milk. 
 
 Lbs. of cured 
 cheese for 
 1 lb. of fat. 
 
 April . . 
 May . . ... 
 
 June 
 
 July . 
 August 
 
 September 
 
 October 
 November 
 
 22 
 68 
 66 
 63 
 49 
 36 
 28 
 15 
 
 3.480 
 3.493 
 3.497 
 3.554 
 3.634 
 3.836 
 4.076 
 4.264 
 
 9.154 
 9.447 
 9.367 
 9.231 
 9.335 
 9.955 
 10.502 
 10.947 
 
 2.630 
 2.704 
 2.679 
 2.593 
 2.568 
 2.594 
 2.591 
 2.573 
 
 Whole season 
 
 347 
 
 3.64 
 
 9.560 
 
 2.628 
 
 Table showing yield of cheese for one pound of fat for each month. 
 
 Percent of fat. 
 
 April and 
 May. 
 
 June 
 
 July. 
 
 August. 
 
 Sept. 
 
 October 
 and 
 
 Novemb'r 
 
 
 No. 
 
 No. 
 
 No. 
 
 No. 
 
 No. 
 
 No. 
 
 Under 3.25 . 
 
 12-2.96 
 
 6—2.99 
 
 3—2.89 
 
 3—2.88 
 
 
 
 3.25—3.50 . . 
 
 33-2.73 
 
 23—2.74 
 
 20—2.70 
 
 11—2.73 
 
 3—2.85 
 
 
 3.50-3.75 
 
 34 -2.62 
 
 32—2.63 
 
 20—2.53 
 
 24—2.54 
 
 10—2.67 
 
 5— 2.S1 
 
 3,75—4.00 
 
 7—2.53 
 
 3—2.47 
 
 7—2.46 
 
 7—2.53 
 
 13— 2.C1 
 
 6—2.62 
 
 4.00—4.25 
 
 3—2.56 
 
 2—2.30 
 
 4—2.33 
 
 3—2.35 
 
 9—2.47 
 
 15-2.64 
 
 Over 4.25 
 
 1—2.15 
 
 
 
 1—1.95 
 
 ^ 1—2.13 
 
 17—2.46 
 
 On the other hand, Dean* has found that uni- 
 
 * Ontario Agricultural College, 21st Annual Report, p. 44. 
 
168 
 
 Milk and Its Products. 
 
 formly a rich milk yields less cheese in proportion 
 to the fat contained in it than a poor milk. His 
 experiments covered a whole season's work in a 
 single factory, the average results of which are shown 
 in the following table: 
 
 
 Yield 
 
 of cheese from rich and poor 
 
 milk. 
 
 
 
 Num- 
 ber of 
 experi- 
 ments. 
 
 Per cent of fat in 
 milk. 
 
 Pounds of green cheese 
 for one pound of fat 
 in milk. 
 
 
 Richer 
 milk. 
 
 Poorer 
 milk. 
 
 Richer 
 milk. 
 
 Poorer 
 milk. 
 
 April 
 
 May. . . . 
 June . 
 July . 
 
 August . . . 
 
 September . 
 
 
 
 6 
 C 
 
 15 
 15 
 
 12 
 12 
 
 14 
 U 
 
 13 
 13 
 
 12 
 12 
 
 13 
 13 
 
 4.21 
 4.09 
 3.94 
 3.78 
 3.82 
 4.01 
 3.99 
 
 3.39 
 3.30 
 3.16 
 
 3.00 
 
 ■ 
 2.91 
 
 3.06 
 
 3.26 
 
 2.66 
 2.68 
 2.68 
 2.73 
 2.74 
 2.68 
 2.82 
 
 2.86 
 2 84 
 2.94 
 3.06 
 3.14 
 3.06 
 
 October . . . 
 
 
 
 3.05 
 
 Average . . 
 
 
 
 
 3.98 
 
 3.15 
 
 2.71 
 
 2.99 
 
 The practical bearing of the relation of the fat 
 to the casein arises in the question as to whether, 
 where milk is bought for cheese making, it should 
 be paid for by weight or according to its percent- 
 age of fat. It does not require proof, that to pay 
 an equal price per pound or hundred weight for 
 milk of all qualities is a gross injustice to those 
 
Relation of Fat to Casein. 169 
 
 who produce the richer milks. If there were a 
 quick, accurate method of determining casein, the 
 logical practice would be to pay for the milk upon 
 the basis of its known content of both fat and 
 casein; but failing in that, it is well to examine 
 in how far we may fall back upon the percentage 
 of fat, the determination of which is both quick 
 and accurate, as a measure for determining the 
 value of milk for cheese making. While there is 
 some disagreement, it seems to be pretty well settled 
 that a milk rich in fat is also richer in casein, 
 and with milk of ordinary quality, including prob- 
 ably nine -tenths of all the milk produced, nearly in 
 proportion to the percentage of fat. So that, even 
 if the richer milk does yield a little less cheese 
 for each pound of fat, the percentage of fat is a 
 much more nearly just measure of its cheese -pro- 
 ducing power than is the weight of the milk, the 
 measure now commonly employed. Further, when 
 the milk is so rich in fat that the casein falls 
 considerably below its normal ratio to the fat, the 
 resulting cheese will be so much richer in fat 
 that it will be of considerably better quality, and 
 subh milk, when pooled with milk poor in fat, will 
 so bring up the quality of the whole product, that it 
 should be paid for at a correspondingly higher rate. 
 The conclusion, therefore, is that the percentage of 
 fat is by far the most accurate measure at present 
 available for the determination of the cheese -produ- 
 cing value of milk, and that milk is practically valu- 
 able for cheese making in proportion to the amount 
 
170 
 
 MilTc and Its Products. 
 
 of fat that it contains, and should be paid for ac- 
 cordingly. 
 
 Loss of fat in cheese making. — It has been a gen- 
 erally accepted idea by cheese -makers, that the neces- 
 sary loss of fat in the whey is much greater 
 when the milk contains a high percentage of fat. 
 Indeed, the statement has been frequently made 
 that all the fat in the milk above 4 per cent is 
 lost in the whey. This idea has had much to do 
 with the disinclination to value milk for cheese 
 making according to its percentage of fat, and, in 
 fact, has been a chief argument in favor of the 
 manufacture of skimmed or partly skimmed cheese. 
 
 The following table by Van Slyke* shows that 
 this idea is erroneous, and that the loss of fat in 
 the whey need be proportionately no greater when 
 the milk is rich than when it is poor in fat. 
 Table showing amount of fat lost and recovered in malting cheese. 
 
 Number of 
 experi- 
 ment. 
 
 Pounds 
 of fat 
 in 100 
 lbs. 
 
 of milk. 
 
 Pounds of 
 fat lost in 
 
 100 lbs. 
 
 of milk. 
 
 Pounds of fat 
 
 recovered in 
 
 100 lbs. of 
 
 milk. 
 
 Pounds of (at 
 
 lost in wbey 
 
 from 100 lbs. 
 
 of fat in 
 
 milk. 
 
 Pounds of fat 
 recovered in 
 green cheese 
 from 100 lbs. 
 
 of fat in milk. 
 
 1 
 
 2.35 
 
 0.154 
 
 2.196 
 
 6.55 
 
 93.45 
 
 2 . 
 
 
 3.01 
 
 0.193 
 
 2.817 
 
 6.42 
 
 93.58 
 
 ■i 
 
 
 3.88 
 
 0.277 
 
 3.603 
 
 7.15 
 
 92.85 
 
 4 
 
 
 3.96 
 
 0.283 
 
 3.677 
 
 7.14 
 
 92.86 
 
 5 
 
 
 4.70 
 
 0.359 
 
 4.341 
 
 7.64 
 
 92.36 
 
 6 . 
 
 
 4.73 
 
 0.331 
 
 4.399 
 
 6.99 
 
 93.01 
 
 7 
 
 
 4.80 
 
 0.373 
 
 4.427 
 
 7.77 
 
 92.23 
 
 8 
 
 6.49 
 
 0.715 
 
 5.775 
 
 11.01 
 
 88.99 
 
 9 
 
 3,70 
 
 0.269 
 
 3.431 
 
 7.26 
 
 92.74 
 
 Other investigators have abundantly confirmed 
 these results. 
 
 *New York Agricultural Experiment Station, Bulletin No. 37, p. 681. 
 
Cooling and Aeration. 171 
 
 Cooling. — All that was said in Chapter V. on 
 "market milk," in regard to cleanliness in drawing 
 the milk, applies equally well to milk that is in- 
 tended for cheese making, but where milk is made 
 into cheese it is not necessary, nor, indeed, is 
 it desirable, that the lactic acid fermentations be 
 checked further than is necessary to allow the milk 
 to come into the cheese maker's hands in the best 
 condition. In cheese making, the fermentations of 
 the milk play a most important part, and while it 
 is not at present known just what fermentations are 
 necessary or most desirable, sufficient is known to as- 
 sure us that a certain amount of lactic acid is not 
 only desirable but necessary for the cheese making 
 process, and enough further is known that those fer- 
 mentations which attack the protein substances, and 
 result in the formation of strong flavors, taints and 
 gases, are all undesirable in cheese making. For 
 the purpose of cheese making, it is desirable that the 
 fat should separate from the other constituents of 
 the milk as little as possible, and to that end the 
 previous treatment of the milk should be such that 
 the separation of » cream will be held back as much 
 as possible. One of the best means of doing this 
 is to cool the milk to the temperature of the air 
 while it is kept constantly in motion. This, be- 
 side helping to keep the cream mixed with the milk, 
 will also favor the escape of any volatile animal 
 products that may be present in the milk, known 
 under the collective name of animal odor, and 
 which would otherwise impart objectionable flavors 
 to the cheese. 
 
172 
 
 Milk and Its Products. 
 
 Aeration. — Passing the milk through an elevated 
 strainer in such a manner that it may fall in 
 finely divided di'ops or streams through the air be- 
 fore it reaches the can, is one of the best means 
 of bringing about this end. This is known as 
 aeration. It cannot be depended 
 upon to destroy or even check the 
 germs of fermentations which may be 
 present in the milk, beyond that 
 due to the reduction of temperature. 
 It is not desirable that milk in- 
 tended for cheese making should 
 be cooled much below the tempera- 
 ture of the air, and one of the best 
 preparations of milk intended for 
 ^cheese making is to allow it to 
 p remain where it will be freely ex- 
 posed to a pure and moderately cool 
 ,, atmosphere. Under ordinary condi- 
 tions, the milks of the evening and 
 the succeeding morning are manufactured together, 
 and the treatment indicated is naturally that of the 
 night's milk. It is highly desirable, however, that 
 the milk of the morning should be cooled to the 
 temperature of the atmosphere before it is taken to 
 the factory, and under ordinary conditions the milk 
 of the night and morning should be taken to the 
 factory in separate cans. 
 
 Ripening. — The lactic acid fermentation is prob- 
 ably one of the most important factors in all the 
 steps of cheese making, and to know to what ex- 
 
 Fig 22 Hodgkin 
 elevated strainer. 
 
Rennet Tests. 
 
 173 
 
 tent it has progressed before the process begins, is 
 exceedingly important to the cheese maker. To this 
 end, several convenient tests may be applied. The 
 veteran, who has attained skill through long manip- 
 ulation, can tell, with a fair degree of accuracy 
 - through the sense of smell and taste the amount 
 of lactic acid present in his milk, but this is not 
 a safe enough guide for those who are inexpe- 
 rienced, or those who expect to make a uniform 
 product in a uniform 
 way from day to day. 
 Rennet tests. — The 
 percentage of lactic 
 acid present in the 
 milk can readily be 
 determined directly by 
 titration with a stand- 
 ard alkali, but the 
 amount of lactic acid 
 present is also quite 
 readily dete r m i n e d 
 by the length of 
 time required for ren- 
 net coagulation, since 
 rennet acts more 
 quickly upon milk 
 the riper it is, and 
 upon this fact two 
 or three simple tests « c u 
 
 have been devised, rig. 23. Monrad rennet test, a, 5 c. c. pipette; 
 m-i • 1 i_ _p A_i &, 50 c. c. graduated flask; c, cup in which 
 
 The simplest 01 these test is made. 
 
174 
 
 Milk and Its Products. 
 
 is to add a spoonful of rennet of known strength 
 to a teacupful of milk and, after stirring the two 
 together thoroughly, to note carefully the time re- 
 quired for coagulation. Another and more exact 
 method, known as the Monrad test, is made as fol- 
 lows : To a measured quantity of milk at a given 
 temperature a measured quantity of rennet of known 
 strength is added; ordinarily the commercial rennet i& 
 diluted nine times for this purpose. The rennet is 
 thoroughly stirred with the milk, and the time re- 
 quired for coagulation is carefully noted. This is 
 simply a development of the cup test, and is better 
 because of its greater delicacy and accuracy; the 
 milk and rennet being more carefully measured, and, 
 diluted rennet being used, a wider range of delicacy 
 
 is reached. Still 
 another form of ren- 
 net test, known as 
 the Marschall test, 
 has been devised. 
 In this test the milk 
 is measured into a 
 vessel, one of whose 
 sides is graduated 
 and in the bottom 
 of which there is a 
 minute oi-ifice. The 
 rennet is added to 
 the milk, and the 
 vessel so placed that the milk can escape from the 
 hole in the bottom. So long as the milk remains 
 
 Pig. 24. Marschall rennet test. 
 
Ripening the Milk. 175 
 
 fluid the stream is continuous, but as soon as the ren- 
 net takes effect and a clot is formed, the stream stops, 
 and no more escapes. The number of spaces of milk 
 which escape is taken as the measure of the ripeness 
 of the milk. When the percentage of lactic acid is 
 great the stream stops sooner than where little acid 
 has been formed, so that in the ripe milk a less 
 number of spaces shows upon the side of the vessel 
 than in the unripe milk. 
 
 Degree of ripeness necessary. — By ripeness of milk 
 for cheese making is meant, as in the case of but- 
 ter making, the degree of lactic acid development that 
 has taken place. For cheese making, the develop- 
 ment of lactic acid should not have proceeded so 
 far that the milk is distinctly sour to the taste, and 
 it should have proceeded far enough so that the 
 whole process of cheddar cheese making, from the 
 time of adding the rennet to putting the cheese in 
 press, will take not more than six hours. This will 
 be indicated by a rennet test of 2% spaces on the 
 Marschall apparatus, or a rennet test of one minute 
 on the Monrad test, when 5 c. c. of diluted com- 
 mercial rennet extract (1 part rennet to 9 of water) 
 are added to 200 c. c. of milk. 
 
 Starters. — In very many cases the milk, when 
 brought to the factory, will not be sufftciently ripe 
 to give the tests indicated above. In that case it 
 should be allowed to ripen before the cheese making < 
 process begins. This may be brought about by 
 heating the, milk up to 85° F., when the germs 
 already present become- more active; but the time 
 
176 Milk and Its Products. 
 
 required for the ripening will be shortened, and more 
 uniform results be obtained if, in addition to the 
 warming, an artificial starter is used. This may be 
 any material containing the germs of lactic fermen- 
 tation in active condition. The whey saved from 
 the previous day, or milk naturally or artificially 
 soured, may be used. An extremely convenient 
 form of starter is made by preparing an artificial 
 ferment in the following way: Ten pounds of 
 whole milk are sterilized at 180° F., then cooled to 
 90°, and sufficient commercial dry lactic ferment 
 added to secure coagulation in twenty -four hours. 
 When coagulated this is added to the extent of 10 
 per cent to enough whole milk to make sufficient 
 starter for one day's use. The amount of starter 
 to be added for the purpose of ripening the milk 
 should be from. 2 to 5 per cent, varying with the 
 temperature of the air and the amount of ripeness 
 that it is necessary to develop after the milk reaches 
 the factory. Enough of the ferment should be re- 
 served each day to prepare ferment for the following 
 day from whole milk; and with care that the ves- 
 sels in which the ferment is made are kept clean 
 and sweet, a single ferment may be propagated for 
 from ten days to two weeks. Such a ferment will 
 give more uniform results, and is less liable to in- 
 troduce taints and bad flavors, than a ferment made 
 from sour whey, and with a little care and atten- 
 tion, the fermentation will go on regularly from day 
 to day. 
 
 Rennet. — The ordinary source of rennet is the 
 
Preparation of Rennet. Ill 
 
 fourth or digestive stomach of a calf that has not 
 yet ceased to live upon milk, though rennet is also 
 found in the stomachs of puppies and pigs, and the 
 latter have occasionally been used as a source of 
 rennet. The active principle of the rennet is found 
 in the folds of the lining membrane of the stomach 
 of the animal, and is greatest in amount when a full 
 meal is just digested. 
 
 Rennet causes coagulation of the casein by con- 
 tact, and is not itself affected by the change. Its 
 action, however, is greatly modified by various con- 
 ditions of the milk, the most important of which 
 are the temperature and the condition of certain of 
 the ash constituents. Rennet is most active at tem- 
 peratures near the body heat, 98° F. At temper- 
 atures below 80° F., the action of rennet is corre- 
 spondingly slow. On the other hand as the temper- 
 ature is raised above 100° P., the activity of the 
 rennet is at first increased, but after about 130° F. 
 is reached the active principle is rapidly weakened 
 and finally destroyed at about 140° F. 
 
 The activity of rennet is also intimately connected 
 with the lime salts in the ash of the milk, and par- 
 ticularly with their condition as to solubility. The 
 presence of soluble salts of lime renders rennet much 
 more active, .while the insoluble salts of lime have 
 a correspondingly retarding effect. Thus, the develop- 
 ment of lactic acid by rendering the lime salts more 
 soluble hastens the action of rennet on the milk. On 
 'the other hand, when milk is heated to a tempera- 
 ture above 150° F. a part of the lime salts are made 
 
178 MilJc and Its Products. 
 
 insoluble, and the action of the rennet correspond- 
 ingly retarded, even though the milk be again cooled 
 to a temperature at which rennet is active. The 
 coagulability of milk is similarly affected by the addi- 
 tion of any lime salt not normally present in milk. 
 Thus, if calcium oxalate or other insoluble salt of 
 lime is added to milk, the action of rennet is 
 retarded. On the other hand, the addition of cal- 
 cium chloride or other soluble salt is followed by a 
 quicker action of the rennet. 
 
 The rennet skin should be obtained from an 
 animal of some age. Still-born calves, or calves less 
 than three days old, furnish a rennet of very inferior 
 quality. The calf should be slaughtered three or 
 four hours after it has had a full meal, and the 
 fourth stomach carefully taken out. This should be 
 emptied by turning inside out and any particles 
 of foreign matter carefully picked off ; it should 
 not be washed with water. It should then be 
 sprinkled with salt and stretched in such a manner 
 that it will readily dry. 
 
 At the present time the preparation of the rennet 
 extract from the skins is entirely a commercial one, 
 and rennet so much superior, on account of its 
 uniform strength and freedom from taints, is fur- 
 nished in this way that it is not advisable to prepare 
 the rennet for use from the skins. In the prepara- 
 tion of the extract, the skins are soaked in warm 
 water to which a little salt has been added until the 
 active principle has been completely removed from 
 them. The resulting extract is filtered, and preserv- 
 
Separation of Whey. 179 
 
 atives, in the shape of salt and a little saltpetre, 
 are added. Rennet so prepared will retain its 
 strength and purity for a considerable length of 
 time, if kept in a cool, dark place. 
 
 Removal of whey. — After the coagulation of the 
 milk is complete its constitution is as follows : 92.5 
 parts soluble, 7.5 parts insoluble. The soluble por- 
 tions are made up of water 87, sugar 4.5, albumin 
 .75, ash .25. The insoluble are made up of casein 
 3.25, fat 3.75, ash .5. The separation of these two 
 is the chief task of the cheese maker, and is brought 
 about partly by mechanical and partly by chemical or 
 physical agents. The chief mechanical agents in 
 the separation are cutting the curd, stirring, and the 
 application of pressure. The chemical and phys- 
 ical agents in effecting the separation are : First, 
 application of heat ; second, development of lactic 
 acid; third, addition of salt; fourth, curing fermenta- 
 tion. These various agents may be applied in va- 
 rious degrees and in various ways, all of which have 
 a greater or less effect upon the character of the 
 resulting cheese, producing an almost endless variety 
 of product. The process that we shall describe is 
 one in common use in America, although first prac- 
 ticed in England. It it known as the American 
 Cheddar process, and is a modification in minor de- 
 tails of the process first employed at least 250 years 
 ago, in the district about the village of Cheddar in 
 Somerset, England, from which it takes its name, 
 and from which it has spread more or less over 
 the whole world. Cheddar cheese is still made in 
 
180 Milk and Its Products. 
 
 Somerset, as well as in other parts of Great Britain, 
 notably Ayrshire. It is with minor variations the 
 process most commonly employed in the United States, 
 Canada and Australia, and one of its distinctive fea- 
 tures, namely the matting of the curd after the whey 
 is drawn, is used in making many other varieties 
 of cheese, as the Cheshire, Leicestershire and Derby- 
 shire in England, the Edam and Gouda in Holland, 
 and perhaps others. 
 
CHAPTER XI. 
 CHEDDAR CHEESE MAKING. 
 
 The successive steps in the manufacture of Ched- 
 dar cheese may be conveniently grouped into seven 
 stages or periods, as follows : Period first, setting ; 
 period second, cutting ; period third, heating ; period 
 fourth, cheddaring ; period fifth, grinding ; period 
 sixth, salting and pressing ; period seventh, curing. 
 
 Period I., setting. — The rennet is most active at 
 temperatures from near that of the body, 98° to 
 100° F., up to about 130° F., and if added to the 
 milk at these temperatures will most quickly cause 
 coagulation (p. 177), but at high temperatures there 
 is more tendency of the fat to separate, and for this 
 reason the milk is warmed to a degree sufi&cient to 
 cause fairly rapid coagulation, and at the same time 
 not injure the fat. This , will vary from 82° to 86° F., 
 according to conditions. The milk, when brought to 
 the factory, is collected in the vats and the whole 
 mass gradually warmed up to the proper tempera- 
 ture, with frequent gentle stirring to prevent any 
 separation of the fat in the form of cream. When 
 the whole mass is warmed up to 82° the milk is 
 tested for ripeness, and if sufficiently ripe the ren- 
 net is added at once, but if the milk is insuffi- 
 
 (181) 
 
182 Milk and Its Products. 
 
 ciently ripe a starter is then added, and the milk 
 allowed to stand at this temperature until a suffi- 
 cient amount of acid has developed, care being 
 taken that it is frequently stirred and no cream 
 allowed to rise. 
 
 The rennet should be added in sufficient quan- 
 tity to cause the milk to coagulate in from ten to 
 fifteen minutes, and to be ready for the knife in 
 from thirty to thirty -five minutes. It was formerly 
 supposed that the amount of rennet added had an 
 efiEect upon the whole process of manufacture, and 
 particularly upon the curing fermentation, but while 
 the matter is still unsettled, later researches go to 
 show that the influence of the rennet upon the 
 curing is probably very slight. The amount of ren- 
 net to be used will also vary with the strength of the 
 extract ; two to three fluid ounces of rennet, of or- 
 dinary strength, per thousand pounds of milk is 
 sufficient. The rennet should be added to the milk 
 in such a way that the coagulation will be uniform 
 throughout the whole mass. If the rennet is added 
 in full strength and at a high temperature, the 
 milk will be immediately curdled as soon as the 
 particles of rennet come in contact with it, and 
 coagulation will begin in part of the mass before 
 the rennet can be thoroughly united with the whole 
 body of milk. The rennet should be diluted with 
 twenty to fifty times its own bulk of cold water. 
 The dilution renders the uniform mingling of the 
 rennet with the milk easier, and the cold water 
 keeps it inactive untU it has been warmed up to the 
 
Setting and Cutting. 183 
 
 temperature of the milk. So soon as the rennet is 
 added, the milk should be quickly and carefully 
 stirred, so that the rennet may be uniformly mingled 
 with every part of it. This stirring should continue 
 until the mixture of rennet and milk is complete, 
 but should stop before any appearance of coagula- 
 tion. The milk in the vat is then allowed to be- 
 come quiet, and remains undisturbed while the pro- 
 cess of coagulation is going on, the object being to 
 secure a uniformly solid clot or eoagulum through 
 the mass. The action of the rennet is not instanta- 
 neous ; the first appearance of coagulation is noticed 
 by a slight thickening of the milk. This gradually 
 increases until the whole mass is solid, and if left 
 undisturbed the action of the rennet continues to 
 contract the coagulated casein and cause a partial 
 separation of the whey. As soon as the coagulation 
 is strong enough, so that the casein will maintain 
 its shape when broken, the contents of the vat are 
 ready for the next step in the process. 
 
 Period II., cutting. — The curd, as the coagulated 
 casein is called, is ready for cutting when under 
 strain it will break with a clean fracture. This is 
 conveniently tested by gently inserting the finger in 
 the curd in an oblique position and slightly raising 
 it, when if the curd breaks clean across the finger 
 it is sufficiently firm for cutting. Cutting is per- 
 formed in order to facilitate the further contraction 
 of the casein and the expulsion of the whey. For- 
 merly the solid mass of curd was broken up into 
 small pieces by any sort of an instrument that 
 
184 Milk and Its Products. 
 
 might be at hand, or simply with the hngers, no 
 care being taken that the pieces of curd should be 
 of uniform shape or size, but now gangs of steel 
 knives, in one of which the blades are arranged 
 horizontally and the other perpendicularly, are used 
 to cut the mass of curd into cubes of about % of 
 an mch in diameter. The fat is retained in the 
 cheese by being enclosed in the meshes of the casein, 
 and in breaking up the mass of casein, a certain 
 number of fat globules is always set free. The 
 care with which the cutting and subsequent hand- 
 ling of the curd is done controls the loss of fat 
 through this source. Formerly, the mass of curd 
 was allowed to become very firm before cutting, but 
 the more recent practice has shown that the best 
 results in expelling the whey from the curd are 
 reached when the curd is cut, so soon as it has 
 sufiiciently coagulated to maintain its form. The 
 curd is cut by passing the horizontal knife through 
 the vat, usually in a longitudinal direction, and then 
 by passing the perpendicular knife both longitudi- 
 nally and crosswise of the vat. It is immaterial 
 whether the horizontal or perpendicular knives are 
 used first. Some skilled cheese -makers prefer the 
 one practice and some the other. The object to be 
 attained is to break up the curd into as uniform 
 a mass of kernels as possible, or, in the language 
 of the cheese -maker, to secure an "even cut." After 
 the curd is cut, the whey begins to escape, and the 
 curd sinks to the bottom of the vat. If allowed to 
 remain undisturbed, the cut surfaces of the particles 
 
Heating or Cooking. 1S5 
 
 of curd readily unite, and in breaking them apart 
 again more fat is lost. Hence as soon as the curd 
 is cut, gentle agitation of the whole mass should 
 begin. This agitation should be suflBcient to cause 
 the particles to move upon one another, but not 
 violent enough to break them up. The curd rapidly 
 shrinks and hardens ; more rapidly upon the outside 
 than the inside. This soon results in the formation 
 of a so-called "membrane," which not only tends 
 to prevent the particles from sticking together, but 
 affords some resistance to further breaking up. This 
 "membrane" is pervious to water, but retains the 
 globules of fat ; so as soon as the contraction has 
 reached this point, or when the curd is well "healed 
 over," the further expulsion of the water should be 
 aided by heat, and this point begins the third step. 
 Period III., heating or cooking. — The term "cook- 
 ing," as applied to the manufacture of cheese, is a 
 misnomer so far as it relates to any change in the 
 composition or condition of the material through 
 the effect of heat. By cooking any ordinarj' sub- 
 stance is meant the application of a degree of heat 
 sufftcient to cause a coagulation of albuminous sub- 
 stances or a breaking down of starchy ones. The 
 degree of heat used in cheese making during this 
 stage never reaches anywhere near this point, and 
 never, except in rare instances, is a temperature of 
 blood heat exceeded. The change to be brought about 
 in this process is wholly the contraction of the curd 
 and the consequent expulsion of water from within 
 the particles. To this end the heat serves a two- 
 
186 Milk and Its Products. 
 
 fold and important part. The curd is contracted to 
 some extent by the action of the rennet still con- 
 tinuing ; also to some extent by the direct applica- 
 tion of the heat, but to a greater extent by the 
 effect of lactic acid upon the curd, the production 
 of lactic acid being greatly favored by the increased 
 temperature. It is desirable that this contraction of 
 the curd in the cooking stage go on uniformly through- 
 out the whole mass. The heat is therefore applied 
 gradually and with constant stirring. As the parti- 
 cles of curd shrink in size, the tendency for them 
 to unite in masses constantly diminishes, and they 
 are broken with greater difficulty, so that while at 
 first extreme care is necessary to prevent the par- 
 ticles of curd from becoming broken, as the temper- 
 ature rises, the stirring may become more rapid and 
 vigorous. The heat should be raised slowly from 
 the setting point of the milk up to 98° F., and it 
 should not be more rapid than 2° in five minutes; 
 and unless the lactic acid develops very rapidly it 
 is better to take even more time than this. When 
 the temperature of 98° F. is reached, the stirring 
 may cease and the particles of curd be allowed to 
 settle upon the bottom of the vat until the curd is 
 thoroughly shrunken and a sufficient amount of 
 lactic acid has been developed. At the end of the 
 cooking stage the particles of curd should have 
 shrunken to less than one -half of their former size, 
 and should have become so hard that when pressed 
 together between the hands, and the pressure sud- 
 denly relaxed, they will fall apart, and show no 
 
Gheddaring or Matting. 187 
 
 tendency to stick together. By this time there should 
 have developed a sufficient amount of lactic acid so 
 that the curd will draw out in fine threads a 
 quarter of an inch long when applied to the hot 
 iron. 
 
 When the curd has reached the highest temper- 
 ature, it may be allowed to settle, and a part of the 
 whey may be drawn off the top of the vat. This 
 is of advantage particularly when the development 
 of lactic acid is likely to be rapid, and it is de- 
 sirable to separate the whey from the curd in a very 
 short time, but sufficient whey should be left to 
 cover all of the curd two or three inches deep 
 until sufficient acid has been developed for the 
 cheddaring process. 
 
 Period IV., cheddaring, or matting. — When suffi- 
 cient acid has developed in the whey, it is drawn 
 off from the vat through the gate or by means 
 of a syphon. The curd is then allowed to mat 
 together into a mass, which is the distinctive fea- 
 ture of the Cheddar process. This matting together 
 may be done either in the vat or in a special 
 vessel, called a curd sink. In the former case, 
 when all the whey is run off the particles of curd 
 are brought together upon the two sides of the vat 
 and a channel opened between them, so that any 
 whey held by the particles of curd may be al- 
 lowed to escape. When the particles of curd are 
 sufficiently matted together to maintain themselves in- 
 tact, the mass is cut up into blocks about 8x8x12 
 inches, and these blocks are turned over so that 
 
188 Milk and Its Products. 
 
 the part that was uppermost comes in contact with 
 the bottom of the vat. A further draining of the 
 whey takes place, and the blocks of curd are next 
 piled upon one another two deep, care being taken 
 in forming these piles that the parts that were ex- 
 posed to the air are turned in. Later on the curd 
 is piled again in still deeper piles, and as the pro- 
 cess continues the mass is piled over and over 
 again, care being taken that the exposed parts of one 
 pile are put into the interior of the succeeding, so 
 that the heat may be uniform throughout the whole 
 mass. In the curd sink the manipulation is not 
 essentially different. The curd sink is a square 
 wooden receptacle fitted with a false slatted bottom 
 and covered with coarse cotton or linen cloth, 
 through which the whey can easily escape. When 
 the time comes for separating the whey, so much 
 as will run off readily is drawn off, and the re- 
 maining whey, mixed with particles of curd, is 
 dipped into the sink, the whey runs off freely 
 through the strainer and slatted bottom, and the 
 curd, being spread over the whole surface of 
 the sink, soon mats into a solid mass, and the 
 piling process goes on the same way as is done 
 in the vat. During this process various changes 
 take place. The pressure of the particles of curd 
 upon one another serves to expel a large part of 
 the whey that still remains ; at the same time the 
 temperature is kept sufficiently high so that the 
 production of lactic acid is not checked. The effect 
 of the acid is to cause a series of marked changes 
 
Grinding. 189 
 
 in the physical condition of the curd. From the 
 condition of a tough, spongy mass when first ched- 
 dared, the curd changes into a smooth, elastic, 
 fibrous condition, not unlike the physical appearance 
 of well cooked, lean meat. When the curd reaches 
 the condition above described it is ready for the 
 next step in the process, and by this time sufficient 
 lactic acid will have developed so that fine threads 
 may be drawn out two to three inches on a hot 
 iron. 
 
 Period V., grinding. — When the curd is ready for 
 grinding, the whey has been removed to so great 
 
 an extent that the pro- 
 duction of lactic acid 
 measurably stops. The 
 curd is ground in or- 
 der to reduce it to 
 particles of convenient 
 size for receiving the 
 salt and for pressing 
 into a solid mass in 
 the cheese. The grind- 
 ing, or more properly 
 the cutting, is done in 
 special machines known 
 
 Fig. 25. "Harris" curd mill. j 'n /^o .-i 
 
 as curd mills. Of the 
 various styles of mills, those are best which cut 
 the curd into pieces of uniform size, without tearing 
 it apart, for the reason that when so treated less fat 
 escapes and the uniformity of size of the pieces aids 
 in the proper and even absorption of the salt by the 
 
190 
 
 Milk and Its Products. 
 
 curd. After the curd is ground, it is kept sufficiently 
 stirred to keep the particles from matting together 
 
 Fig. 26. " MacPherson" curd mill. 
 
 again. A further maturing of the curd takes place, 
 during which it takes on a peculiar nutty flavor, 
 and the particles of casein begin to break down 
 so that the fat may be re- 
 moved by pressure. When 
 this stage is reached the curd 
 is ready for the next step, 
 which is salting. 
 
 Period VI., salting. — Salt is 
 added to the curd primarily for 
 the sake of the flavor it im- 
 parts to the cheese, just as 
 salt is added to butter : but the . 
 addition of the salt to the curd 
 has a further effect in the pro- 
 cess of manufacture. The salt 
 makes the curd drier by reason of extracting the 
 water for its own solution, and at the same time 
 
 Pig. 27. Section of 
 curd mill. 
 
 ' Pohl" 
 
Salting and Pressing. 191 
 
 hardens the curd. It also checks the further devel- 
 opment of lactic acid. The salt should be uniformly 
 mixed through the curd, and the curd kept stirred 
 until it is fully dissolved. A salt of rather coarse 
 grain is preferable for cheese. It requires a some- 
 what longer time for solution, and the particles of 
 the salt are carried to the centre of the pieces of 
 curd more effectually. When the salt is thoroughly 
 dissolved the curd is ready to put in the press. 
 
 During the cheddaring and grinding stage va- 
 rious means, as covering with cloths, etc., have 
 been taken to keep up the temperature of the curd, 
 and at the time when the cheese is ready to salt 
 it should not be below 90° F. When the salt is 
 added the curd should be spread out thin, so that 
 it will cool oif, and when it is put into the press 
 should be at a temperature of from 78° to 82° F. 
 If the curd is put in the press too warm, the fat 
 is more easily pressed out and lost. On the other 
 hand, if the curd is at too low a temperature when 
 put in the press, it is more difficult to make the 
 particles adhere together into a solid mass. The 
 object of pressing the cheese is to bring it into a 
 form suitable for transportation and convenient for 
 consumption. The pressure also removes any surplus 
 moisture that is in the. curd ; but the primary object 
 of pressing is not to remove moisture. In fact, all 
 of the moisture that is removed from the cheese by 
 the press is that held by capillarity between the par- 
 ticles of curd, and practically none can be expressed 
 from the particles themselves. If the curd is too 
 
192 
 
 Milk and Its Products. 
 
 wet at this stage, it is because care was not taken 
 to expel the moisture from the particles of the 
 curd in the cooking process, and it cannot be re- 
 moved by extra pressure. An ideal condition of 
 
 Fig. 28. " Praser" continuous i)ressure gang cheese press. 
 
 the cheese is to so press it that the particles will 
 unite together in as nearly as may be a solid 
 mass. This will depend upon the temperature and 
 maturity of the curd. If the curd is put in press 
 at the stage of maturity corresponding to the 
 beginning of the cheddaring period, it will be 
 very difficult to cause it to unite in a firm mass ; 
 but if it is allowed to mature until the casein 
 shows signs of ))reaking down, and then is not 
 
Curing. 193 
 
 lower than 78° F., a slight amount of pressure 
 will cause the particles to unite in a smooth and 
 solid mass. The pressure should be uniform and 
 continuous for at least twenty hours. Where a 
 screw press is used, care must be taken to tighten 
 the screws as rapidly as they become loose, partic- 
 ularly for the first hour 'after the cheese is put in 
 the press. Those presses that are fitted with ap- 
 pliances for taking up the slack and making the 
 pressure continuous show excellent results in the 
 texture of the cheese. After the cheese has been 
 in the press for three -fourths of an hour it should 
 be taken out, turned, the bandage straightened, and 
 the whole cheese wiped with a cloth wrung out of 
 water as hot as can be borne by the hand. This 
 warming of the surface aids in the formation of a 
 firm, transparent rind, and it improves the appear- 
 ance of the cured cheese. Seamless bandage is 
 practically the only kind now used, and it should 
 be cut of such a length that it will extend over 
 each end of the cheese for an inch and a half or 
 two inches ; when the cheese is put in the press, 
 circular cap cloths should be put between the ends 
 of the cheese and the follower. These cap cloths are 
 allowed to remain upon the cheese after it is taken 
 from the press and while it is curing, and are re- 
 moved just before the cheese is boxed .for market. 
 
 Period VII., curing. — The green cheese, when 
 taken from the press, if exposed to a temperature 
 of about 70° in a pure atmosphere, undergoes a 
 series of fermentations which result in breaking 
 
194 Milh and Its Products. 
 
 down or rendering soluble the casein and in the 
 development of the characteristic flavors peculiar to 
 good cheese. These flavors are almost entirely de- 
 veloped during the ripening process. The ripening 
 is brought about by a series of fermentations that 
 goes on in the cheese. It is not well understood 
 just what these fermentations are ; but it seems 
 evident that at least in the early stages of the 
 curing, lactic acid germs are active, although the 
 greater majority of these disappear after a short 
 time. During the ripening process, oxygen is taken 
 up and carbonic acid given off. The quality of 
 the cheese is best when the ripening process goes 
 on gradually and continually. The higher the tem- 
 perature the faster the ripening will go on ; an 
 extreme temperature of 65° or 70° giving the best 
 results. At the end of from four to six weeks the 
 casein will be so broken down that the cheese is 
 fairly digestible and fit for consumption, though if 
 kept longer under good conditions the cheese will 
 improve for three or four months, and then if kept 
 moderately cool, and in not too moist nor too dry 
 an atmosphere, it may be kept one or two years. 
 During the early part of the curing process the 
 cheeses should be turned upon the shelves every day 
 until a sufficient amount of water has evaporated, 
 so that they no longer tend to lose their shape. 
 Difficulties likely to occur in cheddar cheese mak- 
 ing. — The chief difficulty in cheddar cheese making 
 comes from the presence in the milk of germs 
 which produce fermentations that are undesirable. 
 
Gassy ' ' Curds . 195 
 
 These fermentations usually begin during the cook- 
 ing process, and continue through cheddaring. Or- 
 dinarily they evolve a considerable amount of gas, 
 causing what are known as floating or gassy curds, 
 and are usually accompanied by disagreeable odors 
 and flavors. The formation of the gas in the curd 
 gives it a sponge -like texture, and when the par- 
 ticles of curd are cut across they are seen to be 
 full of minute holes, the condition usually denom- 
 inated pin-holes. The best means of treating this 
 trouble is, of course, prevention; but even with the 
 utmost care by makers of experience, milk contain- 
 ing the germs of these fermentations will find its 
 way into the vat. 
 
 In many cases the trouble from gassy and tainted 
 milk is caused by the milk of one or two dairies, 
 and in exceptional cases the milk of a single cow 
 may infect a whole vat. The particular dairies or 
 even cows that are causing the trouble may usually be 
 detected by employing one of the fermentation tests 
 described in Appendix A. Ordinarily these fermenta- 
 tions do not work with the lactic fermentation ; each 
 hinders the action of the other so that the chief 
 means of overcoming the difiiculty of gas or pin-hole 
 curds is to favor in every way possible the pro- 
 duction of lactic acid. To this end the milk is 
 well ripened before the rennet is added, and the 
 heat is raised as rapidly as possible to a higher 
 temperature of cooking than ordinarily is used. In 
 extreme cases the curds may be heated as high 
 as 104° F. After the whey has been drawn great 
 
196 Milk and Its Products. 
 
 care is taken to keep the temperature of the curd 
 from falling, and at the same time the escape of 
 the gas is favored by frequent turning and piling: 
 of the curd. Where the curds are gassy the ehed- 
 daring process must be continued until the formation 
 of gas has ceased and the holes in the curd have 
 collapsed. In extreme cases, where the gassy curds 
 have produced very strong, undesirable flavors, these 
 may be removed by drenching with hot water. The 
 means used to prevent the development of gas, and 
 to get rid of the gas already formed, ordinarily favor 
 the escape of fat from the cheese, so that while the 
 bad effects of the gassy curd may be largely elimi- 
 nated from the finished cheese, still it is always done 
 at the expense of a certain loss of fat. 
 
 Another difficulty that often confronts the cheese- 
 maker is that coming from the milk arriving in too 
 ripe a condition, not necessarily accompanied by un- 
 desirable fermentations. In the case of such milk, 
 the development of lactic acid is very rapid and the 
 curds, technically described, "work fast." When this 
 occurs, the production of lactic acid is more rapid 
 than the shrinking of the curd, and the whey is 
 sufficiently acid to be drawn off before the curd has 
 shrunken down. In this case, the curd should be 
 thoroughly and continually stirred after the whey 
 is drawn until the whey has been well worked out 
 before the curd is allowed to cheddar ; but where 
 it is known at the beginning of the process that 
 the milk is over -ripe, care should be taken through- 
 out the whole process to use every means to re- 
 
Flavor and Texture. 197 
 
 tard the formation of lactic acid, and at the same 
 time to cause as rapid a shrinking of the curd as 
 possible. To this end, the milk may be set at a 
 lower temperature and a larger amount of rennet 
 used, and when the curd is cut it should be stirred 
 until the whey has well separated before the heat- 
 ing process begins. With care in these particulars, 
 there is slight danger of the formation of acid be- 
 fore the curd has shrunken down. 
 
 Qualities of cheese. — A well cured cheddar cheese 
 of good quality should have about the following 
 composition : 
 
 Per cent. 
 
 Water 34. 
 
 Pat . 36.8 
 
 Casein and albumin ■ . ■ . 25.7 
 
 Sugar, ash, etc. (largely salt) .... 3.5 
 
 100. 
 
 The characteristic flavors should be well pro- 
 nounced but not strong, depending somewhat upon 
 the age of the cheese. The flavor should also be 
 clean ; that is, free from any flavors due to the 
 influence of undesirable fermentations or to foreign 
 matters that may have gained access to the milk 
 through the food or otherwise. The texture should 
 be solid, smooth and firm. When bored with the 
 trier, the plug should come out solid, or nearly so, 
 and smooth. There should be no moisture visible 
 in any part, and no appearance of any separation 
 of the fat from the casein. When crushed, the cheese 
 should readily break down into a smooth, unctuous 
 mass, without indication of the presence of undue 
 
198 Milk and Us Products. 
 
 moisture, and should emit a pleasant, nutty flavor. 
 When broken across, the flaky texture should be 
 manifest, the so-called "flinty break." The color 
 should be uniform, not mottled, and with more or 
 less of a tendency to translucence, especially in new 
 uncolored cheese. The rind should be smooth, with- 
 out cracks, hard and transparent. The bandage 
 should extend evenly over the ends of the cheese for 
 about two inches and should be straight and smooth. 
 The ends of the cheese should be parallel and the 
 sides straight. These various qualities are usually 
 ranked according to the following scale : 
 
 Per cent. 
 
 Flavor . , . . .45 
 
 Texture . . . .... ... 35 
 
 Color . . . . .15 
 
 Finish 5 
 
 100 
 
CHAPTER XII. 
 
 OTHER VARIETIES OF CHEESE. 
 
 Slight variations in any of the minor details of 
 the cheese making processes have a distinct influence 
 on the character of the finished product. A natural 
 result of this is that the varieties of cheese are 
 almost innumerable. Von Klenze* in his Hand Book 
 of Cheese Technology describes no less than 156 dif- 
 ferent kinds, whose manufacture is distributed through 
 Europe and America. Not only is the number of dis- 
 tinct kinds very large, but the same kind or variety 
 varies greatly in character and quality, according to 
 the conditions under which it is made. Without at- 
 tempting to accurately classify the various kinds of 
 cheese, it may be said that they fall roughly into 
 about three natural groups or classes. First, those 
 whose chief characteristics depend upon the amount 
 of water that has been removed in the process of 
 manufacture. These we may call hard or soft cheeses. 
 Second, those whose distinctive qualities depend upon 
 the amount of fat which the cheese contains, whether 
 it is the normal amount of the milk, whether a part 
 of the fat has been removed, as in the case of 
 
 *Von Klenze, Handbueh der Kaserei-Technik, Bremen, 1884. 
 (199) 
 
200 Milk and lU Products. 
 
 skimmed or partially skimmed cheeses, or whether fat 
 has been added to the milk as in the case of the so- 
 called cream cheeses. And third, those whose dis- 
 tinctive characteristics depend upon the sort of fer- 
 mentation to which they have been subjected. In 
 the case of many of these, special ferments are in- 
 troduced into the cheese during the curing process, to 
 bring about the desired characteristics and flavors. 
 The details of manufacture upon which the peculiar 
 characters depend are, in many cases, so intricate 
 and minute that it is practically impossible to so 
 describe them that a novice might successfully fol- 
 low out the directions. The actual practice must in 
 most cases be learned at the hands of an expe- 
 rienced teacher. Even as careful a description as 
 possible is more than could be attempted here, and 
 we shall, therefore, limit our discussion to a few of 
 the better known and most largely manufactured 
 varieties. The introduction of the so-called fancy 
 varieties in America is in its infancy, but is rapidly 
 developing, and bids fair to become a most impor- 
 tant diversification of the dairy industry. 
 
 American home-trade, or stirred-curd cheese. — The 
 popular consumptive demand of most American mar- 
 kets requires a softer and milder flavored cheese 
 than the cheddar or export type. This is brought 
 about by incorporating a larger amount of water with 
 the curd, and by hastening the curing process, and 
 not curing it so far as is ordinarily done with a well- 
 ripened Cheddar. . The details of the manufacture of 
 the American home- trade and the American cheddar 
 
''Home -Trade,'' or ''Stirred- Curd." 201 
 
 or export are in the main similar. In fact, the two 
 processes merge into one another in such a way that 
 we find a regular gradation in the cheese from the 
 softest, mildest, short-keeping stirred-eurd cheese on 
 the one hand to the most solid, long-keeping Ched- 
 dar on the other. The distinctive differences in the 
 two processes of manufacture are that in the home- 
 trade cheese, after the whey is drawn from the curd, 
 the curd is not allowed to mat into a mass or Ched- 
 dar, but is kept stirred in such a way that the whfey 
 will drain off until it is dry enough so that the par- 
 ticles of curd will not unite. It is then salted and, 
 with more or less further maturing of the curd, is 
 pressed and cured. The character of the resulting 
 cheese, however, depends quite as much upon the 
 amount and character of the changes that go on in 
 the curd after the whey is drawn, and before it is 
 put into press, as upon the mere fact of allowing it 
 to pack in a mass (cheddar) or keeping it apart by 
 stirring. If the cheddar variety is ground shortly after 
 matting, and immediately salted and put to press, 
 the resulting cheese will resemble the stirred -curd 
 type. On the other hand, if the stirred -curd is kept 
 warm and frequently stirred, many of the same 
 changes will go on as in the cheddared curd, and 
 the cheese when cured will resemble the cheddar 
 type. 
 
 Another distinction between the two processes is 
 that in the case of the cheddar cheese the aim is to 
 get rid of all the water consistent with a compact 
 union of the particles of casein. In the manufae- 
 
202 Milk and Its Products. 
 
 ture of the stirred -curd cheese, on the other hand, 
 the aim is to retain as much water as possible 
 without having it appear in the form of free water in 
 the cheese. To this end, in the stirred-curd process 
 those influences which tend to contract the curd, 
 namely, the application of heat and the development 
 of lactic acid, are not carried so far as in the Ched- 
 dar process. In fact, in many cases they are not car- 
 ried far enough to remove all of the water necessary, 
 and some remains in the cheese, making a "wet," 
 "sloppy" or "leaky" cheese. 
 
 Because of the larger amount of water it contains, 
 this kind of cheese is profitable to the producer of 
 the milk and to the manufacturer, and when properly 
 made and carefully cured, it may be of excellent 
 quality, being mild, creamy and soft ; but largely, 
 too, because of the large amount of water contained 
 in it, it is easily subject to decomposition changes, 
 goes off flavor rapidly, and does not bear transporta- 
 tion well. 
 
 Sage cheese. — In many parts of the United States 
 this cheese is very popular for local consumption. 
 Its manufacture is not different from the ordinary 
 type of cheese, either cheddar or stirred-curd, but 
 an infusion of sage leaves, or sage extract (in which 
 latter case the green color is secured by an in- 
 fusion of fresh leaves of any inert plant, as clover, 
 green corn, etc.), is added to the milk before the 
 rennet coagulation, and imparts a light greenish 
 color and characteristic flavor to the curd. Ordi- 
 narily, where sage cheese is made, the sage is added 
 
Toung America and Ife.ufchatel. 203 
 
 to only a part of the milk, and two separate curds 
 are manufactured simultaneousl}% and mixed together 
 as they are put in the press, resulting in cheese of 
 a mottled green color. 
 
 Toung America, picnics, pineapple, and truckle 
 cheese. — These are names applied to various forms 
 of small cheeses. The truckle and Young America 
 cheeses in particular are small cheeses of the Ched- 
 dar or other common type, pressed in sizes of six 
 to ten pounds weight. Picnics are somewhat larger 
 and are usually pressed in 10 -inch hoops and weigh 
 from 20 to 25 pounds. They are usually soft and 
 mild -flavored. The pineapple cheeses are pressed in 
 shapes suggested by their name, and are generally 
 made as firm and solid as possible. 
 
 Neufchatel is a soft uncured cheese, made by coagu- 
 lating milk with rennet, allowing the resulting curd 
 to become mildly acid and then removing the sur- 
 plus moisture by drainage and pressure, after which 
 the curd is ground, salted, molded in small cylin- 
 ders 1% inches in diameter by 2% inches long and 
 wrapped first in thin parchment paper and then in 
 tin foil. Good Neufchatel should be soft, smooth 
 and melting in the mouth without "mushiness," due 
 to the retention of too much moisture. When properly 
 made it can be subjected to very heavy pressure with- 
 out losing its melting texture. Its flavor when 
 fresh is simply the flavor of clean, mildly acid coagu- 
 lated milk. The successful manufacture of Neuf- 
 chatel depends upon securing both fine texture and 
 good flavor, for while, as a rule, these two qualities 
 
204 Milk and Its Products. 
 
 are closely connected, it is quite possible to have 
 good texture with objectionable flavor. It is prob- 
 able that the same conditions of temperature and 
 germ growth that are most favorable to ripening 
 cream for churning are also most favorable for the 
 manufacture of Neufchatel cheese. At any rate, the 
 milk should have some degree of ripeness before the 
 rennet is added. It is essential that the milk be 
 clean and pure, that the acidity is developed to the 
 proper point in the curd, and that sufficient pressure 
 is applied. When experience in these last two points 
 is gained, the remainder of the process is compara- 
 tively simple, and in fact, many of the details may 
 be varied to a greater or less extent. Good clean 
 milk is not less important than in cheddar cheese 
 making, as gassy ferments often make trouble. A 
 good pure -culture starter, giving a mild develop- 
 ment of acid, will prove of great assistance in hand- 
 ling gassy milk. The rennet is added to the milk 
 at a low temperature (70° to 80° F.) at the rate of 
 1% to 2% ounces per 1,000 pounds. Too little ren- 
 net will give trouble by making a curd that is very 
 difficult to drain, and that tends to pass through 
 the press cloths when pressed. An excess of rennet 
 results in a curd of hard texture. It is better to 
 add the rennet to the whole mass of milk in a vat, 
 and then as soon as the rennet is thoroughly mixed 
 with the milk, to draw it off into "shot-gun" cans 
 (8 inches in diameter and 20 inches deep) for coagu- 
 lation. The milk should be warm enough and also 
 ripe enough, so that coagulation will take place 
 
Neufchatel. 205 
 
 before much cream rises to the surface. The tem- 
 perature of the room may vary within rather wide 
 limits, though if it is above 80° F. the curd is likely 
 to be hard and tough, while if it is 60° F. or below, 
 the curd is not injured, though the process is greatly 
 retarded. Probably the same rule holds here as in 
 cream -ripening, namely, that it is not possible to 
 name a single temperature arbitrarily as the cor- 
 rect one. The most important point in the whole 
 process is to determine wlien the curd should be 
 dumped from the coagulating cans upon the drain- 
 ing cloths. It should stand until the whey is 
 markedly acid to the taste, as much so as mildly 
 ripened cream, and until the hand passed down 
 between the sides of the can and the curd notes 
 that the latter is firm, with a peculiar elastic cush- 
 iony feel. The amount of whey that gathers on the 
 top of the curd is not a safe indication of the time 
 to dump, for at high temperatures a large amount 
 of whey often separates while it is still sweet, and 
 in case of gassy fermentations the curd floats and 
 the whey is found at the bottom. If the cans are 
 dumped before sufficient acid has developed, it will 
 be very difficult to drain the curds, the flavor will 
 be very bad, the texture pasty and slimy, and later,, 
 as the acid develops, an additional amount of whey 
 will separate, making a leaky cheese. When ready, 
 the cans of coagulated milk should be dumped on 
 draining racks 15x24 inches, with slatted bottoms 
 covered with heavy, closely -woven cotton sheeting. 
 The dumping should be carefully and skilfully done, 
 
206 Milk and Its Products. 
 
 so that the curd slides out of the can with as little 
 breaking as possible. The conditions are best when 
 the mass of curd, on being dumped, retains its form 
 and breaks with a clean vitreous fracture. The 
 time required for drainage may range from two to 
 twenty-four hours, varying with the temperature, 
 amount of rennet used, amount of acidity developed, 
 and other unknown factors. When dry enough to 
 handle easily, the cloths are folded up in such a 
 manner as to enclose the curd, and the whole is 
 pressed under rather heavy pressure till the proper 
 consistency is secured. When taken from the press 
 the cakes of curd are brought to a uniform con- 
 sistency by kneading or working, or they may be 
 passed through an ordinary meat chopper. About 
 1% per cent of salt is then thoroughly incorporated 
 and the cheese molded into the desired shape. 
 The molding is a matter of some difBculty, as the 
 particles of cheese move easily on themselves, while 
 they tend to adhere to metal or wooden surfaces. 
 Large factories have specially constructed machines 
 for molding the cheese. On a small scale, the most 
 satisfactory implement is a smooth tin tube of the 
 proper diameter and long enough to hold two or 
 three cheeses. The tube is filled full of the curd 
 and then forced out of one end with a smoothly 
 fitting piston, after which the cheeses are cut apart 
 with a thread and neatly wrapped first in thin parch- 
 ment paper and then in tin foil. According to the 
 quality of milk, from 60 to 80 standard cheeses should 
 be made from 100 pounds of milk. 
 
Philadelphia or Square Creams. 207 
 
 Philadelphia or square cream cheese. — This is a 
 soft cheese growing in popularity in proximity to 
 many of our larger markets. It resembles the Neuf- 
 chatel, but is made of cream of varying degrees of 
 richness and is put up in a different form. It is 
 molded in flat, thin cakes 3x4 inches, in a flat tin 
 mold, wrapped in parchment paper, and packed for 
 shipment. Its manufacture is practically the same 
 as Neufchatel, and, in fact, there is more or less 
 confusion of nomenclature between the two, as well 
 as a good deal of variation in fat content, some 
 brands of Neufchatel having a higher fat content 
 than some brands of square cream, and vice versa. 
 
 Some of the older writers describe a cream cheese 
 made by simply draining and lightly pressing in 
 square blocks a thick cream obtained by setting milk 
 in shallow pans, heating over water till the cream 
 "crinkles," and setting in a cool place for twelve to 
 twenty -four hours. 
 
 Limburger. — The Limburger is one of the varieties 
 of cheese whose characteristics are due to specific 
 fermentations brought into the cheese during the 
 ripening process. These fermentations result in a 
 well known putrefactive odor and pungent flavor. 
 According to Monrad,* the manufacture of Limburger 
 in America and Europe is not greatly different. Or- 
 dinarily the cheese is made from whole milk, but 
 frequently skimmed or partly skimmed milk is used. 
 In Europe the copper kettle is commonly employed ; 
 in America both the kettle and the ordinary rectan- 
 
 * Cheese-making in Switzerland. Winnetka, 111., 1896. 
 
208 Milk and Its Products. 
 
 gular cheese vat are used. In the latter case the 
 curd is made iu much the same way as for ordinary 
 cheese up to the point when the whey is drawn off. 
 The milk is set at a rather high temperature (92° to 
 100° i\). The curd is broken into pieces the size 
 of a hen's egg, and allowed to settle to the bottom 
 of the kettle. It is then scooped out and put in 
 rectangular molds arranged on tables, so that the 
 whey may drain off. The molds are carefully turned 
 till the whey has measurably ceased running, and the 
 cheeses will maintain their form. They are then 
 placed in rows on a flat table with thin pieces of 
 board between them, and subjected to light pressure 
 from the sides. The cheeses are turned frequently at 
 first, and then at longer intervals, till at the end of 
 thirty -six to forty -eight hours they may be taken 
 from the press. They are then salted by rubbing 
 salt on the ends and flat sides for three or four 
 days. After the first salting they are laid on the 
 table in single layers, afterward they are piled, at 
 first two deep, then three or four deep, so that the 
 , absorption of the salt may be promoted. During 
 salting and pressing they are kept at a uniform tem- 
 perature of from 59° to 63° F. They are then cured 
 in a cool (60° F.), well -ventilated cellar nearly satur- 
 ated with moisture, with careful watching and much 
 manipulation and turning. With the ripening they 
 begin to soften. The curd, at first hard, takes on 
 the characteristic glassy, greasy appearance, at the 
 same time that the rind becomes at first yellow, then 
 reddish yellow. The softening begins on the outside 
 
Prepared Cheese. 209 
 
 and proceeds toward the center, and the cheeses are 
 considered to be marketable when one -quarter of the 
 cheese has taken on its characteristic texture. 
 
 Imitation Swiss cheese. — A considerable amount of 
 cheese closely resembling the true Eramenthaler is 
 made in America. Its main distinctive characteristic 
 lies in its peculiar flavor, and in the appearance of 
 the peculiar, so-called Swiss holes in its texture. 
 Both of these are due to specific fermentations, 
 which take place in the cheese during the curing 
 process. (See Emmenthaler cheese, page 219.) 
 
 These are the principal varieties of cheese that 
 are manufactured to any large extent in America. 
 There are, however, a number of brands of cheese 
 upon the market that may properlj' be classed under 
 the general name of 
 
 Prepared cheese. — These fancy brands are in gen- 
 eral made from an ordinary cheese of good quality, 
 by removing the rind and reducing the remainder 
 to a homogeneous, more or less pulpy, mass. To this 
 is added a certain amount of additional fat, either in 
 the shape of butter or other fat, and some flavoring 
 matter in the form of cayenne pepper, brandy, or 
 something of like nature. The cheese is then packed 
 closely in fancy glass or earthenware packages, sealed 
 tightly, and marketed. The names under which it is 
 sold vary with the manufacturer and with the recipe 
 under which it is made. Many of them are sold 
 under registered trade -marks. Some of the better 
 known are Club House, Meadow Sweet, Canadian 
 Club, etc. 
 
 N 
 
210 Milk and Its Products. 
 
 Among the varieties of cheese of foreign manu- 
 facture, the following are worthy of mention: 
 
 English cheeses. — The various dairy localities in 
 England produce cheeses bearing their distinctive 
 geographical names. In the main, they are of the 
 'cheddar type, and differ from the true cheddar only 
 in details of manufacture and in slight differences 
 in texture and flavor, in much the same way that 
 the American home -trade cheese differs from the 
 American cheddar. Of the English cheeses, the best 
 known are the English Cheddar, Cheshire and Stilton; 
 others worthy of mention are Leicestershire, Lanca- 
 shire, Derbyshire, single and double Gloucester, Wens- 
 leydale and Wiltshire. 
 
 Stilton. — The manufacture of Stilton cheese is con- 
 fined almost entirely to Leicestershire, England. Its 
 manufacture is quite different from that of the com- 
 mon type of English and American cheeses, and in 
 many respects more nearly resembles many of the 
 Continental varieties, and is almost exclusively eon- 
 fined to private dairies. It is made from sweet 
 milk, and more commonly separate curds are made 
 from both night's and morning's milk, the two being 
 brought together when ready for the hoops. Stilton 
 cheese is also made from a single curd, and in this 
 case the night's milk is held till morning and 
 mixed with the morning's milk. It is commonly sup- 
 posed that Stilton cheese is made from milk which 
 has been reinforced with more or less cream, but 
 this is not the case at the present time ; in fact, 
 Stilton cheese of good quality can be made from 
 
Stilton. 
 
 211 
 
 Pig. 29. Straining-eloths containing curd. 
 (Redrawn from Jour. Royal Agr. Soc, 
 3rd Series, vol. x.) 
 
 milk not particularly rich in fat. In making Stilton 
 cheese the fresh milk is put into a circular tin vat of 
 sufficient size to hold the milk of the whole dairy. 
 The milk is allowed 
 
 to cool to about 85° 
 P., and enough ren- 
 net is added to cause 
 a firm coagulation in 
 an hour or an hour 
 and a quarter. While 
 the milk is coagu- 
 lating the strainers 
 are arranged in 
 sinks, as follows: The sinks must be large 
 enough to hold all the milk that is made at one 
 time. Many makers prefer earthenware, though on 
 account 'of the less cost, sinks of heavy tin are 
 frequently used. They are about six inches deep, two 
 to two and a half feet wide, and of any convenient 
 length, and are simply fitted with outlets and plugs. 
 For straining the curds stout linen cloths are used. 
 These are a yard square and are arranged in the 
 sinks as shown in Fig. 29, and are supported by 
 sticks laid across the sink in such a way that the 
 ends of each cloth may be gathered up without dis- 
 turbing those next to it. When the milk is firmly 
 coagulated, so that the curd is somewhat harder 
 than for ordinary cheddar cheese making, the plugs 
 are put into the sink and the curd dipped into 
 the strainer with the curd ladle or scoop shown in 
 Fig. 30. , This is done with a peculiar deft motion 
 
212 
 
 Milk and Its Products. 
 
 Stilton curd scoop. 
 
 in such a way that the scoop takes up a thin slab 
 
 of curd, breaking it as little as possible. The curd 
 
 is carefully laid in the strainer, each strainer receiv- 
 ing a slice in turn 
 until all the contents 
 of the vat are col- 
 lected in the strainers. 
 The strainers when full 
 should contain about 
 three to four gal- 
 lons. After dipping, 
 
 the whey begins to separate and is allowed to stand 
 
 until the curds are well covered, when the plugs are 
 
 withdrawn and the whey allowed to run off. The 
 
 ends of the strainers are then gathered up, brought 
 
 closely about the curd, three corners being held in 
 
 one hand and the 
 
 whole tightened with 
 
 the fourth, as shown 
 
 in Fig. 31 ; care "being 
 
 taken in doing this 
 
 that the curd is not 
 
 broken. The pressure 
 
 of the cloth causes the 
 
 whey to separate more 
 
 freely, and at intervals 
 
 of an hour the cloths 
 
 are tightened about the 
 
 curd until eight or ten 
 
 hours have passed, when the curd should be firm 
 
 and solid, and the whey entirely separated. The 
 
 Pig. 31. Metliod of tightening strainer 
 clotiis. (Redrawn from .Jour. Royal 
 Agr. Soc, 3rd Series, vol. x.) 
 
Stilton. 
 
 213 
 
 cloths are now removed from the curd and the curd 
 
 is cut into pieces about four inches square, and 
 
 spread in the bottom of the sink and allowed to 
 
 remain till morning or until it 
 
 has taken on a good degree of 
 
 acidity, so that it is distinctly 
 
 sour to the taste. If the room 
 
 has been held at a temperature 
 
 between 60° and 65° F., this will 
 
 occur when the night's curd is 
 
 36 and the morning's curd 24 
 
 hours old. The two curds are 
 
 then coarselj^ broken up 
 
 with the fingers, mixed 
 
 together, salted (about 
 
 one ounce to three and 
 
 a half pounds of curd), 
 
 and put in the hoop 
 
 shown in Pig. 32. The 
 
 hoops are made of tin, 7 inches in diameter and 
 
 15 inches high, open at both ends and perforated 
 
 with numerous holes. The empty hoop is set upon 
 
 a thin piece of board 9 inches square, covered with a 
 
 piece of muslin. The curd is put in the hoop 
 
 loosely, care being taken that the larger pieces fall 
 
 in the center, and the smaller ones go to the outside. 
 
 The hoops when full are set aside to drain. Each 
 
 day the curd is turned in the hoop, a fresh board 
 
 and piece of cloth being used each time. After six 
 
 to eight days the curd next the hoop begins to take 
 
 on a fermentation, which gives it a moist appearance 
 
 Fig. 32. Hoop for Stilton cheese. 
 
214 Milk and Its Products 
 
 and an aromatic odor. The curd also shrinks slightly 
 so that the hoop slips from it easily. The cheeses 
 are then ready for the coating process. The hoops 
 are removed entirely and the cheese taken into 
 another room, . where the temperature is maintained 
 at from 55° to 60° F., and the air is kept nearly 
 saturated with moisture. The cheeses are scraped 
 with a dull knife, the cracks being filled up with 
 the material scraped from the more prominent places. 
 After the scraping, a bandage is pinned firmly to 
 the cheese. The scraping is continued from day 
 to day for two or three days, clean bandages being 
 put on each time until the coat begins to appear. 
 This is seen in the formation of a white mold, and 
 also in the appearance of dry patchbs upon the ban- 
 dage. The bandages are now removed from the 
 cheese, and it remains in the coating-room for about 
 two weeks, being turned every day, and resting on 
 a board covered with cloth. When the coat has 
 fully formed, the surface of the cheese is a light 
 drab, of a wrinkled appearance, and is then ready 
 for the curing -room. The curing -room is kept at 
 the same or a little higher temperature than the 
 coating-room, and the atmosphere may be somewhat 
 drier, though care must be taken that it is not too 
 dry. Curing goes on slowly for two or three 
 months, after which the cheese maj' be removed to 
 a cool cellar and will continue to improve for some 
 time longer. During the curing process the mold 
 begins to grow in the interior of the cheese, and 
 when fully ripe the cheese should be evenly mottled 
 
Stilto7i. 215 
 
 and veined with blue mold tlirougli its . whole sub- 
 stance. A well-made and well-cured Stilton cheese 
 has a rough, wrinkled, drab exterior. The cheese 
 
 Big. 33. Stilton cheese, from '" Stilton Cheese Making," by J. Marshall Dugdale. 
 Jour. Royal Agr, Soc, 3rd Series, vol. x., through the courtesy of the Sec- 
 retary of the Royal Agricultural Society of England. 
 
 itself is of a soft, uniform texture, pale-colored, and 
 evenly streaked with mold. The flavor is mild and 
 largely characteristic of the mold. The appearance 
 of the cheese is well shown in the cut, Fig. 33. 
 
216 Milk and Its Products. 
 
 Cheshire. — Cheshire is a cheese of the ordinary 
 type, soft in texture and rather high in flavor. It 
 takes its name from the county in England where 
 it is most largely made, and is one of the most 
 important of English cheeses. Cheshire cheese is 
 made from whole milk, night's and morning's milk 
 mixed together and of some degree of ripeness. In 
 many dairies the night's milk is skimmed in the 
 morning before the morning's milk is added to it, 
 and the cream so obtained reserved to be added to 
 the cream of the following day at the same time 
 that the cream removed the day before is added to 
 the milk from which the cream is taken. This is 
 done in order to secure a certain degree of ripe- 
 ness. The milk is set at about 85° F., with enough 
 rennet to cause a rather firm coagulation in about 
 an hour. It is then cut with a perpendicular knife 
 lengthwise of the vat, and allowed to stand ten 
 minutes or until a considerable amount of whey is 
 separated, and is then cut crosswise and a second 
 time lengthwise. It is not ordinarily cut with the 
 horizontal knife at all. After cutting, it is care- 
 fully stirred with the hand for about an hour, dur- 
 ing the latter part of which time heat is applied 
 to bring the contents of the vat back again to 
 85° F. When the curd is firm enough so that a 
 piece thrown 15 to 18 inches in the air and caught 
 in the hand does not break it is allowed to settle, 
 usually for about half an hour, but before any acid 
 develops in the whey the curd is carefully pushed 
 to one end of the vat and the whey drawn off. 
 
Cheshire. 217 
 
 The curd then mats and is cut and piled much as 
 in the Cheddar system, except that the pieces are 
 cut smaller and the cutting is renewed each time 
 the curd is turned, and the piling is done in such 
 a way that the curd does not flatten out. The 
 acidity and moisture of the curd is regulated dur- 
 ing this cutting and piling process. If the curd 
 is too wet, it is turned and piled frequently. If it 
 is too acid and dry it is allowed to lie louger and 
 not turned so often. When some acid is developed, 
 so that the curd takes on a glistening appearance 
 and begins to grow slightly fibrous, it is finely 
 ground in a peg mill, salted and put in the hoops 
 with strainer cloth about it but not under pressure. 
 At night it is turned and returned to the hoops. 
 The next morning it is again turned and then put 
 in the press with very slight pressure. Each suc- 
 ceeding day the turning is continued and the pres- 
 sure slightly increased until it has been pressed for 
 five days in all. It is then taken from the press 
 and allowed to stand one day in the hoops with- 
 out pressure, after which it is taken out and a 
 bandage pasted on with flour paste. It is allowed 
 to stand three days in the press-room, and then 
 put in the curing -room at a temperature not above 
 65°, and cured for three or four weeks. The 
 cheese should all be of the same height, and to 
 bring this about hoops of varying diameter are used 
 so that the variation in milk from day to day will 
 make no difference in the height of the cheese. If 
 a cheese is too high after the first or second day 
 
218 Milk and Its Products. 
 
 in the press it is put in a hoop of larger diameter 
 and vice versa When the cheese is put in the cur- 
 ing-room, the growth of a white mold on the ends is 
 encouraged by laying on the upper end of the cheese 
 a plate or round piece of slate. The cheeses are 
 kept on straw in the curing-room, and when ready 
 for market the ends of the cheese, except where the 
 plate has lain, are cleaned and polished, and the 
 marks of the straw show in the white mold in the 
 center. Cheshire cheese is usually colored. When 
 of good quality it is of a soft and somewhat gran- 
 ular texture, dissolving readily on the tongue, and 
 with a pronounced and rather sharp cheese flavor. 
 
 Lancashire.— luancsishire cheese is very similar to 
 Cheshire, though it is made somewhat softer and the 
 flavor is more pronounced. No heat is used to aid 
 in the separation of the whey, and ordinarily, when 
 ready for the press, the curd is divided into two 
 portions, one of which is mixed with the curd 
 retained from the preceding day and pressed, and 
 the other kept to be mixed with the curd made on 
 the following day. 
 
 Derbyshire and Leicestershire. — These cheeses are 
 made by modiflcations of the Cheddar process. They 
 are intended to produce a somewhat softer cheese to 
 ripen in a shorter time. Both are pressed in flat 
 shapes, not over six inches in height and about six- 
 teen inches in diameter. The Derbyshire is white, 
 the Leicestershire highly colored. Both should be 
 covered with dark mold when ready for the market. 
 They bear the same relation to English Cheddar 
 
Wensleydale and Gorgonzola. 219 
 
 cheese that the soft varieties of of home -trade cheese 
 do to American export Cheddars. 
 
 Wensleydale. — Wensleydale cheese is made in cer- 
 tain districts in Yorkshire, England. It occupies an 
 intermediate position between the Stilton on the one 
 hand and the ordinary hard cheese on the other. In 
 texture and flavor, and in the characteristic veins 
 of blue mold it quite closely resembles the Stilton, 
 but it is made after a process somewhat resembling 
 the ordinar3' Derby or Leicestershire or American 
 home- trade processes, and is pressed in a bandage 
 in an ordinary press. It is cured at a temperature 
 of about 60° F , care being taken that the growth of 
 the mold is facilitated even to the extent of burrow- 
 ing the cheese with skewers if the mold does not 
 grow with suilRcient rapidity. 
 
 Gorgonzola. — Gorgonzola is an Italian blue-molded 
 cheese closely resembling Stilton in texture, though 
 it is usually of inferior flavor. Considerable quan- 
 tities of Gorgonzola are imported into this countrj', 
 but their quality is not at all uniform and the pro- 
 cess of manufacture, resembling that given for Stil- 
 ton in the main, is not systematically carried out 
 by the peasants in the north of Italy, where it is 
 made. 
 
 Emmenthaler , Qruyere, Swiss or Schweitzer. — The 
 cheese made in the mountains of Switzerland has a 
 history reaching back to the seventeenth century,* 
 and many of the old customs are still used ; but, as 
 
 *Monrad, Cheese making in Switeerland. Winnetka, 111., 1896. 
 
220 Milk and Its Products. 
 
 might be expected, the various localities have devel- 
 oped many varieties of this general type, in the same 
 way that the different forms of eheddar and allierl 
 cheese have come to differ from one another. It is 
 generally considered that the cheese known as Em- 
 menthaler is typical of the whole group of Swiss 
 cheeses. The Emmenthaler cheese is made in a 
 large copper kettle instead of a vat, and ordinarily the 
 curd made in one vessel is pressed as a single 
 cheese. After the curd has been coagulated with ren- 
 net, it is broken up in various ways into small pieces 
 as nearly uniform in size as possible, and then heated; 
 with careful stirring and attention, up to 135° or 
 140° F. After heating, the curd is allowed to sink 
 to the bottom of the vessel in a solid mass, and 
 while in this condition the bandage is slipped around 
 it and the whole mass of curd conveyed to the 
 hoops, where it is pressed. In the subsequent curing 
 the curd is usually salted from the outside of the 
 cheese as it is curing, and during the curing pro- 
 cess certain fermentations go on which produce large 
 holes in the cheese. These holes in perfect cheese 
 should be uniform in size and at equal distances from 
 one another. The casein itself breaks down into a 
 cheese of solid, uniform texture and characteristic fla- 
 vor. It has been asserted that the characteristic fla- 
 vors of the Swiss cheese are due to the character of 
 the Alpine pastures upon which the cows feed, Ijut it 
 is altogether likely that the curing fermentations have 
 as much or more to do with developing these flavors, 
 Edam. — The round Dutch cheeses, colored red, 
 
Edam. 221 
 
 that are common in all. markets take their name 
 from Edam, a small town in North Holland, though 
 the cheeses made in the whole of North Holland are 
 practically of this variety. The cheeses are made 
 almost wholly in private dairies, though there are a 
 few factories in which the milk of several farmers is 
 pooled together. The cheeses are made from partly 
 skimmed milk ; ordinarily the milk of the evening 
 is put at once into the cheese making tub, and in 
 the morning the cream that has risen is removed 
 from it for making butter. The fresh morning's 
 milk is added and the whole set immediately at a 
 temperature of 85° P., with enough rennet to coagu- 
 late it in about 40 minutes somewhat softer than for*" 
 ordinary cheese making. When the coagulation is 
 sufficiently advanced the curd is broken with a wire 
 curd breaker, the bars of which are about three- 
 fourths of an inch apart. The breaking is done at 
 first gently into large pieces and afterward more 
 vigorously, a constant agitation being kept up by the 
 breaker which results in breaking the curd into finer 
 and finer pieces. After the whey begins to separate 
 a portion is drawn off and heated upon a stove, the 
 agitation meanwhile of the curd and the remaining 
 whey being constantly kept up. When the whey is 
 sufficiently warm so that when added to the whole 
 mass it will bring the contents of the tub up to 85° P., 
 the heated whey is added and the stirring with the 
 breaker kept up for a full hour, at the end of which 
 time the particles of curd should be about the size of 
 kernels of wheat, and firm and hard, but still entirely 
 
222 
 
 Milk and Its Products. 
 
 sweet. The curd is then allowed to settle on the 
 bottom of the tub. When it is sufficiently matted so 
 that it will hang together it is carefully turned over 
 and doubled up at one side of the tub, which is 
 slightly elevated for the purpose. The whey is then 
 dipped off and the curd made as firm as possible in 
 the tub by pressure with a piece of board and an iron 
 weight. When all the whey has been removed that 
 will run off readily, the curd is broken up with the 
 
 hands and packed in the 
 molds shown in Fig. 34. 
 It is made as firm as 
 
 ^ possible in the mold by 
 
 pressure with the hand 
 
 Fig. 34. Mold for Edam cheese. 
 
 until it will maintain its 
 shape. It is then removed 
 from the mold, neatly 
 wrapped in cotton cloths 
 and replaced. The covers 
 are put on and the molds put in the press for three 
 hours. When removed from the press the cheese 
 should be round or nearly round in shape. They are 
 put on cup -shaped supports and salted by thoroughly 
 rubbing the outside with salt. They are then set 
 aside, covered with salt, turned and rubbed frequently 
 for three or four days. (Sometimes the salt is added 
 by immersion in saturated brine.) They are kept in 
 the salt as long as any whey is drawn out and are 
 then put on shelves in the curing- rooms still in the 
 cup-shaped support to help maintain their form. The 
 curing-rooms are kept at ordinary temperatures. In 
 
Edam. 
 
 223 
 
 many places they are the cow stables that are vacant 
 for the summer. The temperature will seldom rise 
 higher than 65° F. After about three or four weeks 
 they became hard and firm aud covered with a white 
 mold. They are then taken down, thoroughl.y washed 
 
 Fig. 35. The Market Sqii.ire, Alkmaar, Holland. From a pliotograph 
 by the author, Jlay 21, 1837. 
 
 in whey, all the mold scrubbed off, dried and greased 
 with linseed oil, when they are ready for the market. 
 The merchants purchase them in large numbers at the 
 weekly markets in the different villages. A typical 
 market scene is shown in the cut (Fig. 35). When 
 taken to the warehouses they are colored red, wrapped 
 in tin foil and packed for transportation. The curing 
 
224 Milk and Its Products. 
 
 process is not completed at the time the cheese is 
 ( marketed. An Edam cheese at three or four weeks 
 old is of a tough, elastic texture and scarce any 
 flavor. Six or eight months or more are required to 
 break down the casein and develop the flavor as it is 
 found in the perfect Edam cheese, and this ordinarily 
 takes place while the cheeses are in the warehouse or 
 in course of exportation. 
 
 Gouda. — Gouda cheeses are made in South Holland 
 by a process very similar to the manufacture of 
 Edam. The whey is not so completely separated, 
 and the resulting cheese is therefore softer. It is 
 pressed in molds of a flat, oval shape and about 
 ten or twelve pounds weight, and is cured faster 
 than Edam, so that at six weeks to two months 
 old it is a cheese similar in flavor and texture to 
 a well made Cheddar, although somewhat drier. 
 
 Roquefort. — This is a soft or semi-soft cheese, 
 made in France. In some respects it is the most fa- 
 mous of all varieties of cheese. It is sometimes made 
 from goats' as well as -cows' milk, and it has peculiar 
 characteristics imparted by specific fermentations that 
 are brought about in the curing process. The curing 
 is done in caves in limestone rock, where the air is 
 uniform in temperature, and in order to bring about 
 the desired fermentations the germs are added to the 
 curd in the process of manufacture. These germs 
 are often cultivated upon bread or similar substance, 
 and this, crumbled up, is mingled with the curd 
 in order to insure the proper fermentation in the 
 cheese. Roquefort cheese, when well made and 
 
Brie and Camembert. 225 
 
 cured, is of a rather soft texture, and the whole 
 mass is permeated with the molds, imparting a 
 characteristic flavor to the cheese. 
 
 Brie. — Another soft French cheese. The milk is 
 put into small, circular vessels and the rennet added. 
 The curd is allowed to remain until it has become 
 sufficiently firm to be removed from the whey in one 
 piece. It is then carefully taken up and put in 
 such a position that the whey may drain from it. 
 It is turned frequently and carefully until sufficient 
 whey has drained away so that the cheeses will 
 maintain their form. They are then lightly salted 
 and put away to cure. During the curing process 
 molds develop on the outside, but the fermenta- 
 tions that go on upon the inside of the cheese 
 result in the breaking down of the casein into a 
 creamy mass of a strong, piquant flavor. The molds 
 upon the outside give to the cheese a strong odor 
 of decomposition. 
 
 In very many cases. Brie cneese is put upon the 
 market in a very much more immature form, so that 
 it has a firm, though somewhat soft texture. If 
 allowed to become fully ripe, though, it breaks down 
 into a semi-liquid mass similar to Camembert. 
 
 Camembert. — Camembert cheese is a soft cheese 
 of French manufacture 3 to 4 inches in diameter 
 and X to % inches thick. When fully ripe, the 
 cheese is coated with a heavy growth of red or 
 reddish brown mold, and the interior breaks down 
 into a soft, plastic semi-liquid mass, of pungent odor 
 and piquant flavor. In the manufacture of Camem- 
 o 
 
226 
 
 and Its Products. 
 
 bert cheese the rennet is added at a rather low tem- 
 perature and in small quantity, so that eight to ten 
 hours are required before the curd is firm enough 
 for the further treatment. In some cases a culture 
 of the mold from an old cheese is added to the milk 
 before the rennet, in order to facilitate the growth 
 of the mold during the ripening process. When the 
 milk is coagulated into rather a firm curd, 
 the curd and whey is ladled into the mold 
 shown in the cut, Fig. 36, which is placed 
 upon a straw mat arranged on a table so 
 that the whey may drain off. In 
 ladling the curd into the mold 
 care is taken that each ladleful 
 is deposited with as little break- 
 age of the curd as possible, and 
 particularly that the 
 mold, when full, is 
 covered at the top 
 with but a single slice 
 of the curd. The curds 
 are allowed to remain 
 in the molds until enough whey has escaped so that 
 the cheeses may be turned without breaking the curd. 
 They are then carefully turned and put upon fresh 
 mats, at intervals of twelve hours, when in the 
 course of three or four days the cheese will be 
 sufficiently firm so that the molds may be removed. 
 After the molds are removed, turning is continued 
 until the mold begins to appear on the surface. 
 The cheeses are then put in a damp curing -room, at a 
 
 Fig. 36. Ladle and mold for Camembert 
 cheese. 
 
D'Isigny and Pont L'Uvique. 
 
 227 
 
 low temperature — 55° to 60° — for the remainder of the 
 ripening process, which requires from four to six weeks. 
 
 D'Isigny. — D'Isigny cheese is similar to Camem- 
 bert and Brie, and intermediate in size between 
 them ; in fact, D'Isigny so closely resembles Brie 
 that they are often indistinguishable, and, as a 
 matter of fact, D'Isigny is little more than a trade 
 name for a smaller form of Brie. 
 
 Pont L'Uvique. — Pont L'EvSque is a soft French 
 cheese of rather firmer consistency than Camembert. 
 The milk is set at the usual temperature, and when 
 the curd is firm enough to handle, it is gently cut 
 into rather large cubes, which are carefully placed 
 upon a straw mat. As the whey begins to separate 
 and run off and the curd becomes firmer, the ends of 
 the mat are brought together in such a way that a 
 slight nressure is brought upon the curd. This is 
 continued until the curd is firm enough so that it 
 can be placed in tin molds like 
 that shown in the cut. Fig. 37. 
 The molds are filled and placed 
 upon a straw mat. The molds 
 are turned once or twice a day 
 until the cheese is firm enough 
 so that the mold may be re- 
 moved. Mold begins to appear 
 upon the cheese, which is kept 
 at a temperature a little above 
 60°. When the cheeses are well molded they are 
 removed to a damp room of a 
 55° to 58°. When the curing 
 
 li-ig. '37. Mold for 
 Pont L'EvSque cheese. 
 
 temperature from 
 process is com- 
 
228 
 
 Milk and Its Products. 
 
 plete, the cheeses are of a soft consistency similar to 
 that of an unripe Brie, but with a characteristic, well 
 ripened flavor fully developed. 
 
 Port du Salut is one of the firmest French 
 cheeses, and when well made is of a texture similar 
 to the best type of American home -trade cheese, 
 with a pleasant, nutty flavor. The milk is set at 
 a rather high temperature and enough rennet added 
 to bring firm coagulation in thirty minutes. The 
 curd is then cut and heated to 104° and allowed 
 
 to remain in the whey 
 until it takes on a pe- 
 culiar rubber -like con- 
 sistency. It is then put 
 in the hoop shown in 
 the cut, Fig. 38, which 
 is lined with a strainer 
 cloth and subjected to 
 slight pressure. When taken from the press it is 
 slowly ripened at a low temperature. 
 
 Parmesan . — A very hard Italian cheese made 
 from milk with very little fat, and from which a 
 large part of the water has been expelled. In curing 
 it takes on a rather sharp flavor, and naturally it 
 can be kept in almost any climate for almost any 
 length of time. It is so hard that it is ordinarily 
 grated before being used, and is almost wholly 
 used to add piquancy to soups, sauces, and the 
 like. 
 
 Fig. 38. Hoop for Port du Salut cheese. 
 
CHAPTER Xm. 
 BT-PBODUCTS OF THE DAIRY. 
 
 The by-products of the dairy are skimmed milk, 
 buttermilk and whey, and a variety of products 
 that may be manufactured from them. The utiliza- 
 tion of these by-products to the best advantage is 
 an important part of the economy of dairy manu- 
 facture. 
 
 Skimmed milk, buttermilk and whey. — By far the 
 larger part of the dairy by-products must of neces- 
 sity be utilized as food for animals, either because 
 of the cost of transportation or for lack of facility 
 in marketing many of the rather perishable products 
 that can be made from them. All of these products 
 make a valuable food for animals, of course in pro- 
 portion to the amount of the normal constituents of 
 the milk which they contain. Whey is less valuable 
 than skimmed milk or buttermilk, because it has lost 
 the greater part of its casein as well as fat, but 
 it still is of sufBcient value to render its utilization 
 of importance. Naturally, we expect that young ani- 
 mals (calves and pigs) will thrive the best upon 
 these products, though skimmed milk has frequently 
 "been fed to cows with good results. All three are, 
 however, so bulky that some more concentrated food 
 
 C229)_ 
 
230 Milh and Its Products. 
 
 should be fed in connection with them, if they are 
 used to the best advantage. When economically 
 fed to young pigs and calves, skimmed milk and 
 buttermilk may be made to return about fifteen cents 
 per hundred weight, and whey about one-third less. 
 These products are of value for food in proportion 
 as the milk sugar has not been changed to lactic 
 acid. They may be fed in unlimited quantities with- 
 out ill results upon the health of the animal, ex- 
 cept that occasionally when the milk is very sour, 
 or when fermentations other than lactic have set 
 in, derangements of the digestive organs, diarrhoea, 
 etc., sometimes occur. It is, therefore, advisable that 
 all of these products should be fed in as fresh a con- 
 dition as possible, and it has been found in many 
 instances that the custom of sterilizing or partially 
 sterilizing the skimmed milk or whey at the factory, 
 by injecting a jet of steam into it until the whole 
 is heated up to about 180° F., is practical, and is fol- 
 lowed by beneficial results. 
 
 Dried casein, paper sizing. — The casein of milk 
 in a dry form is useful in certain manufacturing 
 process, and has been found to be particularly val- 
 uable for the preparation of sizing for paper. The 
 manufacture of dry casein for this purpose has 
 come to be an important means of utilizing 
 skimmed milk in many creameries, and its prepara- 
 tion is comparatively simple. The skimmed milk is 
 collected in a vat and the curd precipitated with a 
 mineral acid. A mixture of acetic and sulphuric 
 acids is commonly used, and from X to 1 per cent 
 
Milh Sugar. 231 
 
 is sufficient. When the curd has formed, which 
 will be as soon as the acid is thoroughly mixed 
 with the milk, the whey is drawn off and the 
 curd washed two or three times with warm water. 
 It is then taken out and pressed as dry as possible, 
 after which it is ground rather fine in a peg mill 
 and then dried in an oven till perfectly dry. The 
 amount usually realised from the skimmed milk in 
 this way is not more than may be realized when 
 it is skilfully fed to animals. 
 
 Milk sugar. — Milk contains between 4 and 5 per 
 cent of milk sugar, and the manufacture of this sugar 
 has come to be an important industry. In the manu- 
 facture, whey is preferably used, or if skimmed milk 
 the casein is first coagulated and removed. The 
 water is then removed by evaporation until the crys- 
 tals of sugar are formed. Various methods are used 
 to rid the sugar of albumin and other materials con- 
 tained in the whey. Formerly this was a somewhat 
 difficult operation, and added considerably to the ex- 
 pense of the manufacture, but recently improvements 
 have been made in this respect, so that the cost of 
 the manufacture of the sugar is much lessened. The 
 growth of the industry has been very rapid, result- 
 ing in a much lower price for the product and a very 
 much increased consumption. Formerly, almost the 
 only use of milk sugar was medicinal. Now, be- 
 cause of its digestibility, it forms an important in- 
 gredient of many of the so-called infants' and inva- 
 lids' foods. It is usually prepared in the form of a 
 white crystalline powder, only mildly sweet to the 
 taste. 
 
232 Milk and Its Produrfs. 
 
 Dutch cheese (cottage cheese, schmierhase, pot cheese, 
 etc.). — A toothsome and nutritious article of food is 
 made from sour skimmed milk or buttermilk by al- 
 lowing the casein to coagulate by the action of lactic 
 acid already formed, and then expelling the water by 
 the aid of heat. A considerable number of products 
 locally distinct, and differing in the degree of dryness 
 of the casein, are made in this way, the general pro- 
 cess of manufacture being to take sour buttermilk, or 
 skimmed milk which has coagulated, heating gently to 
 from 85° to 125° F., according to circumstances, drain- 
 ing off the whey through a cloth strainer, and then 
 reducing the texture of the resulting curd by knead- 
 ing with the hands or a pestle ; salt is added, and 
 the product is improved by the addition of a small 
 amount of cream or butter, and occasionally by the 
 use of some of the more common spices, as nutmeg, 
 caraway, etc. It is commonly made only for domestic 
 consumption, but in most cities and villages, es- 
 pecially during the summer months, there is a con- 
 siderable demand for fresh cheese of this , sort, and 
 its manufacture is often a source of revenue to fac- 
 tories suitably located. It is usually sold and eaten 
 in a fresh state, but it may be subjected to cer- 
 tain curing processes, which quite materially change 
 its character, and which vary widely in different 
 localities. 
 
 Whey cheese (primost and myseost) . — These are pro- 
 ducts manufactured from whey in some of the north 
 European countries and among the Scandinavians in 
 our own. They are really forms of evaporated whey: 
 
Primost, Cheese Food. 233 
 
 and, according to Monrad,* are made somewhat as 
 follows : The whey, not too sour, is boiled in a 
 suitable vessel under a slow fire, care being taken 
 that it is not scorched or burnt ; when the albumi- 
 nous matters are coagulated they are removed to facil- 
 itate evaporation, and the evaporation is carried on 
 until the whole mass assumes a syrupy condition; 
 the albuminous matters are then returned to the 
 condensed whey, the whole is removed from the flre 
 and mixed rapidly until in the form of a thick 
 mush ; some cream is then added and the material 
 pressed in brick shaped moulds, and after a day or 
 two is ready for market. It is practically unknown 
 except in those districts where the Scandinavian 
 population is large. 
 
 Cheese food. — Within the last few years an en- 
 terprising cheese-maker, Mr. J. J. Angus, of Wiscon- 
 sin, has perfected a system of manufacturing what 
 he calls a complete cheese food. It is simply a pro- 
 duct containing all the constituents of the milk in 
 a condensed form. An ordinary cheddar cheese is 
 first made and cured ; the whey is evaporated to a 
 syrupy consistency, and the cheese from a corre- 
 sponding amount of milk is ground down to a pasty 
 consistency and mixed with the evaporated whey. 
 The resulting mass is pressed into cakes of conve- 
 nient size, and under ordinary conditions will keep 
 a long time. The cheese food is a soft, homoge- 
 neous substance of a mildly cheese -like, sweetish 
 flavor. 
 
 •A B C of Cheese-making. Winnetka, ni. 1689. 
 
234 Milh and Its Products. 
 
 Koumiss is a beverage made from milk that has 
 undergone alcoholic fermentation. It resembles but- 
 termilk in taste, but has a frothy appearance and 
 the casein of the milk is coagulated into a fine curd. 
 It was originally made from mares' milk by various 
 wandering tribes in Russia and Asia. It has been 
 found to possess certain dietic properties, and is 
 now prepared from cows' milk by various formulas. 
 According to Fleischman, one of the best formu- 
 las is as follows : 
 
 One hundred pounds of separator skim milk is 
 mixed with 42 pounds of water, 1.75 pounds of 
 granulated sugar, .75 pounds of milk-sugar and 
 5/2 to 6 ounces of good yeast, and is allowed to 
 stand for 32 hours at a temperature of 100° F. 
 During this time the mixture is stirred about six 
 times at equal intervals. It is then decanted into 
 patent -stoppered bottles, the stoppers secured and 
 the bottles , put into a cellar at a temperature of 
 55° P. It should be used within six days. 
 
 Kephir is a similar beverage to Koumiss. In its 
 preparation the fermentation is brought about by 
 certain bodies, the so-called Kephir grains, of which 
 very little is known. Kephit is but little known 
 in this country. 
 
 Wheyn. — Quite recently there has been patented 
 in this country by Alexander Bernstein, of Berlin, 
 Germany, a nourishing, mildly stimulating drink with 
 the above name. It is, according to the specifications 
 of the letters patent, a sour, sterilized whey, from 
 which the albuminous matter and fat have been re- 
 
Wheyn. 235 
 
 moved. It is put up without further treatment, or it 
 may be flavored with hops or other material, which 
 may also be carbonated, or subjected to a mild alco- 
 holic fermentation 
 
CHAPTER XIV. 
 
 BUTTER AND CBEESE FACTORIES. 
 
 Location of creameries. — In the location of a 
 creamery no one thing is more important than to 
 secure a well drained site, and yet this is in many 
 cases evidently the last thing thought of. Cream- 
 eries are located in any out of the way corner or 
 bit of waste land that happens to be at hand. 
 The drainage is no less an important matter to be 
 considered in selecting a creamery site than in se- 
 lecting a house site. The foundation of cleanliness 
 in a creamery begins with the sewer, and unless 
 the waste materials can be completely and quickly 
 drawn away the labor of keeping the whole prem- 
 ises clean is very much enhanced. 
 
 Other things being equal, then, elevated ground 
 should be selected as a proper site for a creamery, 
 and if the advantage of the elevation can be made 
 use of in the arrangement of the working rooms, 
 so much the better. Another matter that may prove 
 of considerable value in many cases is a regard for 
 the natural or artificial shelter that may be given the 
 creamery building. A difference of six or eight de- 
 grees in the work-room temperature may be easily 
 secured by having a due regard to the advantages of 
 
 (236) 
 
Arrangement of Creameries. 
 
 237 
 
 shade from groves or the channels of natural air 
 drainage. On the other hand, it is not well to lo- 
 cate the building on a too bleak or exposed site, and 
 yet the great majority of creameries are either ex- 
 posed to the 
 full rays of 
 the August 
 sun or to the 
 bleak winds of 
 winter. 
 
 Arrang e- 
 ment of build- 
 in g. — Two 
 general princi- 
 ples govern 
 the arrange- 
 ment of cream- 
 ery buildings. In the one, the milk is taken in at such 
 an elevation that it may flow by gravity from the 
 weighing can to the receiving vat, thence to the tem- 
 pering vat, thence to the separator, and finally to the 
 skimmed milk and cream vats. In the other, the milk 
 is taken in on a level with the work-room floor, and 
 is elevated by pumps. Both plans have their advan- 
 tages and disadvantages. The main advantage of 
 what may be called the "gravity" system is, that 
 the milk flows by its own weight during the whole 
 course of manufacture, and no pumps, troublesome 
 to keep clean, are necessary. As an offset to this 
 advantage, it entails a considerable amount of ex- 
 tra labor in ascending and descending the neces- 
 
 Pig. 39. Diagram of creamery arranged upon tlie 
 "gravity" plan. 
 
238 
 
 Milk and Its Products. 
 
 sary stairs or 
 the other hand, 
 
 steps. The pumping system, on 
 is economical of labor, but intro- 
 duces one or 
 more pumps, 
 through which 
 the milk must 
 be passed, and 
 which are al- 
 ways, even 
 when of the 
 simplest pat- 
 tern, more or 
 less difficult to 
 keep clean, 
 and exceeding- 
 ly liable to be 
 neglected. In 
 the outline diagrams is a creamery arranged ac- 
 cording to either system. By reference to the ground 
 plan (Fig. 41, page 239), it may be seen that in 
 either case the amount of floor space required is the 
 same. In Fig. 39 is shown the elevation under 
 the "gravity" arrangement, with the exception that 
 the skimmed milk vat is shown elevated. Here the 
 milk is taken in at A, passes to B the receiving 
 vat, thence to C the tempering vat, thence to D the 
 separator, thence to E the cream vat, and through 
 the pump H to F the skimmed milk vat. In the 
 pumping system. Fig. 40, the same letters indicate 
 corresponding parts. It will be seen here that the 
 milk is pumped through G from B to C. Referring 
 
 Fi^. 40. Diagram of creamery arranged upon the 
 pumping" plan. 
 
Arrangement of Creameries. 
 
 239 
 
 again, then, to the floor plan, if the arrangement be 
 according to the pumping system, the operator, stand- 
 
 Fig. 41. Ground plan of creamery in Figs, 39 and io. A, weighing can; JB, 
 receiving vat ; C, tempering vat ; i), separator ; E, cream vat ; J, churn : 
 K, butter worker; i, cold storage room ; M, ofBce ; i?, boiler room ; O, fuel. 
 
 ing near his scales and receiving vat A, is but a step 
 from the separator D and the boiler N, and can easily 
 give attention to all parts of his factory. Whereas, 
 if the creamery is arranged upon the " gravity " 
 plan, he must be constantly ascending and descend- 
 ing a series of steps between A and D. It would 
 seem, therefore, that when the factory is to be a 
 
240 Milk and Its Products. 
 
 large one, requiring the services of more than one 
 man, that the "gravity" system is preferable, be- 
 cause of doing away with the objectionable pumps. 
 Whereas, if the factory is to be a small one, and 
 one man is to do all the work, the amount of 
 labor saved by the more compact pumping system 
 will more than overbalance the objection arising 
 from pumps. In a factory of the size indicated, 
 handling from three to five thousand pounds of 
 milk per day, a floor space of about 18 x 24 feet 
 will be required. In larger factories, it wUl be 
 found of advantage, in controlling the temperature, 
 to introduce partitions, so that the receiving and 
 separating room may be separated from the churn- 
 ing and working room, and if much butter is to 
 be made up into prints, a third, colder i-oom, for 
 printing the butter, will be found of great advan- 
 tage during the warm part of the year. Here, too, 
 the question of labor again comes into play. When 
 the creamery is so small that all the work is done 
 by one man, labor is economized by having all the 
 operations conducted in one room, but where two or 
 three, or even more men are employed, it will be 
 found of advantage to have separate rooms for the 
 different operations. 
 
 Construction. — The building should be laid upon 
 solid foundation walls rather than upon piers. 
 Besides adding decidedly to the appearance of the 
 building, it aids materially in keeping the build- 
 ing warm in winter and cool in summer. In regard 
 to the floors, cement floors are the most expensive 
 
Construction and Superstructure. 241 
 
 and the most durable, and if well laid and com- 
 posed of the best materials, are entirely satisfactory. 
 But wooden floors, tightly laid upon a well -drained 
 foundation, are fairly durable, and when out of re- 
 pair may be easily replaced at comparatively small 
 cost. Whatever the floors, they must be thor- 
 oughly sewered. The floor should slant rapidly 
 to the gutter, so that all water will quickly run 
 off through a thoroughly trapped iron pipe until the 
 outside of the building is reached, after which 
 well -glazed sewer pipe may be used. An abundant 
 supply of pure water is indispensable. This, under 
 ordinary conditions, will be obtained from a well. 
 A bored or driven well is less liable to contami- 
 nation than an open dug well, but in any event 
 the site of the well should be chosen with due 
 regard to possible sources of contamination. If 
 the water is very abundant and at a temperature 
 below 48°, a supply of ice is not indispensable, 
 except for cold storage purposes, but it will be 
 found in most cases to be of great advantage. 
 In any event, the means of readily securing and 
 maintaining in the cream a temperature of 50° P. 
 or below is indispensable. Water and steam pipes 
 should be carried to all parts of the building where 
 ^heir presence may be of advantage for cleaning 
 purposes. 
 
 The superstructure may be as elaborate or as 
 
 simple as desired. At the least, it should offer as 
 
 good protection from the elements as a well-built 
 
 house does. In fact, the construction need not 
 
 p 
 
242 
 
 Milk and Its Products. 
 
 differ from that of ordinary house construction, 
 except that ceiling on the inside take the place of 
 plaster. 
 
 The inside finish should be of matched and 
 planed lumber, thoroughly protected with hard oil. 
 
 F 
 
 
 
 
 
 
 
 
 
 
 
 
 C 
 
 B 
 
 
 -0- 
 
 - 
 
 
 C 
 
 
 
 for 
 
 » 1 
 
 c 
 
 
 j= 
 
 
 
 B 
 
 . 
 
 
 
 
 
 
 
 
 
 T ., , _. 
 
 Fig. 42. Plan of cheese factory properly arranged. 
 
 It should be needless to say that the outside should 
 be neatly and tastefully painted, yet well -painted 
 creameries are the exception and not the rule. 
 
 Cheese factories. — All that was said in regard to 
 the location of creameries applies with equal force 
 to cheese factories. Heretofore, perhaps, even less 
 attention has been paid to the drainage of cheese 
 factories than to creameries, but it is quite as neces- 
 sary. The arrangement of the cheese factory is con- 
 siderably simpler than that of the creamery, and mis- 
 
Arrangement of Cheese Factories. 
 
 243 
 
 takes in arrangement are less liable to be made. 
 The governing principle should be that the milk, in 
 its transformation from milk to cheese, should pass 
 in one direction from the weighing can toward the 
 curing room. The outlines given, Figs. 42 and 
 
 F 
 1 1 
 
 
 
 
 
 
 
 
 
 
 
 
 C 
 
 .jjj . 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 B 
 
 
 B 
 
 
 B 
 
 
 
 
 
 E 
 
 
 
 -B- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ( 
 
 ^ 
 
 
 ^ 
 
 
 
 
 
 
 
 
 "iT~ 
 
 
 
 
 
 
 Fig. 43. Plan of cheese factory improperly arranged. 
 
 43, show factories properly and improperly arranged. 
 In Fig. 42, the milk taken in at A passes into the 
 vats at B, from thence to the curd sink C, and the 
 press D, and finally to the curing room E, con- 
 stantly in one direction and with a minimum of hand 
 labor. Whereas, in Fig. 43, following the same let- 
 ters, the milk or curd travels from one end of the 
 room to the other and back again. While cheese 
 factories, as a rule, are used only during the warm 
 months of the year, and perhaps for that reason 
 
244 Milk and Its Products. 
 
 may be less warmly built, still it is not sufiacient 
 that the superstructure be merely of siding nailed 
 to the joists, leaving the inside bare. While, per- 
 haps, it is not necessary that the outer siding be 
 double, or that building paper be used upon the 
 joists, still the joists should always be ceiled upon 
 the inside and the ceiling neatly finished in oil. 
 The construction of the curing room is the most 
 important part of the cheese factory. Here the 
 construction should be of such a nature that a 
 fairly constant temperature may be maintained. This 
 can hardly be secured unless the building is covered 
 on the outside with two thicknesses of boards, with 
 paper between and tightly ceiled upon the inside. 
 This part of the factory, at least, should always be 
 upon a solid wall foundation. Constructed in this 
 way, if care is taken to ventilate the building thor- 
 oughly at night, and to close it tight during the 
 day time, a fairly cool curing room can be secured 
 even during the hottest weather ; but the temperature 
 can be much more satisfactorily regulated if the ven- 
 tilation comes through a sub -earth duct for a con- 
 siderable distance. This may be arranged by laying 
 a three or four -inch glazed sewer pipe at least four 
 feet deep, from a point on the surface fifteen or 
 twenty rods from the building, and opening into 
 the center of the curing room through the floor. 
 If the mouth of this sub-earth duct can be placed 
 in such a position that the prevailing winds will 
 blow toward it, a circulation of cool air can more 
 easily and certainly be secured. 
 
Farm Dairy Buildings. 245 
 
 Combined butter and cheese factories. — The connec- 
 tion between the butter and cheese markets is such 
 that it is coming to be of considerable advantage 
 for a factory to be able to make either butter or 
 cheese. In many eases but little additional room or 
 expense is necessary. If in the creamery the receiv- 
 ing vat is of the same construction as an ordinary 
 cheese vat, that is, piped so that hot water or steam 
 can be introduced around it, all that is necessary in 
 order to make cheese is to add a cheese press and 
 the necessary curing room. In a cheese factory the 
 addition of a separator, churn and worker serves to 
 transform it into a creamery. It is true that the 
 presence of the necessary equipment is always a 
 temptation toward the making of skimmed milk cheese 
 during a part of the year, but a due regard for the 
 reputation of the products of the factory will always 
 result in making either full cream cheese or butter 
 alone. Naturally the manufacture of cheese is most 
 advantageous during the summer months, and the 
 manufacture of butter most profitable during the 
 winter months. It is not at all unlikely that dairy 
 manufacture will tend in this direction in the future, 
 instead of certain localities being devoted almost ex- 
 clusively to butter manufacture and others to cheese 
 manufacture, as in the past. 
 
 Farm dairy buildings. — Heretofore the farm dairy 
 work has shared with the other farm industries and 
 the domestic life the room necessary to its prosecu- 
 tion, and this has been and still is a main reason 
 for the general inferiority of farm dairy products. In 
 
246 Milk and Its Products. 
 
 order that the farm dairy be successful, it is neces- 
 sary that some certain place be set aside rigorously 
 for its prosecution. The dairy cannot be associated 
 with the kitchen, the vegetable cellar, or any other 
 part of the farm buildings except to its own detri- 
 ment. The room or building devoted to the farm 
 dairy need not be large nor elaborate. It should 
 simply secure a room of convenient size, shut off 
 from ahy other occupation, well lighted, well venti- 
 lated, well drained, and reasonably cool in tempera- 
 ture. It is entirely possible that this room be a 
 part of the house cellar, but if so it should have 
 its own individual exit, and be completely shut off 
 from the cellar at large. In the same way it may 
 be a part of any of the farm out -buildings, or it 
 may be a building by itself. As to whether in a 
 moderate sized dairy, where say twenty to forty cows 
 are kept, the dairy should have a building separate 
 from others or not, depends largely upon the way 
 in which the dairy work is carried on. If the dairy 
 is so large that power is required for the churning, 
 or if the cream is raised by a gravity process, it 
 will undoubtedly be of advantage that the dairy 
 should occupy a separate building ; but if the cream 
 is separated by centrifugal process, and power is not 
 required for churning, then the milk may be sepa- 
 rated in the barn adjoining the stable, and only the 
 cream carried to the dairy room proper. There are 
 many advantages in this latter plan. In the first 
 place, the labor of carrying the milk to the dairy, 
 and the skimmed milk and buttermilk away, is done 
 
Farm Dairy Buildings. 247 
 
 away with. In the second place, the room required 
 for ripening the cream and churning the butter is 
 very small, even for a dairy of considerable size, and 
 may easily be fitted up in a cool corner of the 
 cellar. The only disadvantage is that steam for 
 cleaning the utensils is not conveniently at hand, 
 but the advantages in most cases will outweigh this 
 single disadvantage. If this requisite of the farm 
 dairy building or apartment is secured, namely, a 
 room devoted to nothing but butter or cheese manu- 
 facture — light, airy and well drained — there is no 
 reason why the very highest quality of products 
 should not be made under such conditions, and 
 there are several reasons why a better product can 
 be made than under the ordinary factory conditions, 
 where the production and care of the milk is in the 
 hands of a large number of persons, over whom the 
 butter -maker or cheese -maker can at best exercise 
 only partial control. 
 
CHAPTER XV. 
 
 STATISTICS AND ECONOMICS OF THE DAIRY 
 INDUSTRY. 
 
 The dairy industry in its development has fully 
 kept pace with other industries and with the pop- 
 ulation. The total number of milch cows has in- 
 creased between two and three fold since 1850, 
 though in 1890 there were slightly fewer cows in 
 proportion to the population than in 1850. But while 
 the number of cows has not increased faster than the 
 population, their product has materially done so. 
 This is seen in the average yield per cow and in 
 the increase in the production of butter and cheese. 
 In 1850 the average yield per cow was 166% gallons. 
 This had increased in 1890 to 315.4 gallons, or 
 nearly 100 per cent. The total production of butter 
 was nearly four times as ranch in 1890 as it was in 
 1850, and the production of cheese slightly less than 
 2% times as much. 
 
 The various details of this development are well 
 shown in the following tables, compiled from the 
 United States Census reports by the Dairy Division 
 of the United States Department of Agriculture :* 
 
 *U. S. Dept. Agr., Bureau of Animal Industry, Bulletin No. 11 (Dairy 
 No. 1). 
 
statistics of Production. 
 
 249 
 
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 5oo n 
 
 
 o mo Oi o ^ 
 
 « ■* t^CO Ov 
 
 as" 
 
 «g 
 
 
 S.S- 
 
 
 1:? 
 
 1 
 
 in-wfo 
 
 
 oo M 
 
 i o< -o- 1/100 00 moo >o <o o c 
 
 Tiinoi FOOT 
 
 « ino. NCQ mo ir>o m fo 
 
 M 01 0) -^co oo u-icoco H 
 
 J m i>- ui m n >o < 
 >o o H In c 
 
 fj^ 1^ -s ij's soft's" ■"s.s; 
 
 „ -it 
 
 u > (0 rt 
 
 J|s2 
 
 G£'o „ « 
 
 U O ^ rt rt " 
 
 5 nJ 
 
 .H-S|^ 
 
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 3 -bO 
 
 „'S^ ."'COB 
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 ^ E 3" .5 SI O wo 
 
 es 
 
 •Si 
 
 •ei 
 
 B rt 
 
 SasSaS °-S 
 
 o- » a u S.S » B a 
 
 &-a i^ u - <o ^ ■) » 
 
 = 3 = 
 
 BttuS-tssSu^ 
 
 as' 
 
 § 3-S « Sfi f 
 
 ,SgBV,t 
 u o «J ~iS 
 
 5. -S 
 
 £•0*3 
 
 rt M u 
 
 u r u 
 
 a^i^ 
 
 o p 
 
 oop>u:n>i 10 —"0 
 "a's^SsBisgi--- 
 
 *j5B«J;B'«.tia>> 
 
 s o sis ■■°" I •-"■■- 
 
 <i- " 9 u ■? B - ^ 
 
 = =-c 
 
 S^S 
 
 'ar*'! 
 
 "■aili^ 
 
 
 5B-S?-! 
 
 •S o 
 
 s|SS"„.E-g 
 
 S-oR,n * £ > <j-d 
 
 B-S u a5.iiTj „ w ** ^ 
 °'".S6aB.Sga«S 
 
 jSi^"" K « I " 0'°*' 
 ■g-S °gB^aa's^'i!«g 
 »=■ aa"°~.S°.S2"5 
 £m 3 u rt s bov B bO E b 
 
 3? .5K»ognB.2"«° 
 "> ft t? .0 o ^rS £ K rtS -2 
 
 uooo.u: S'3-3 S„SgoS 
 
 5 9 = eJ= £ S* K B 3 " 
 
250 
 
 Milk and Its Products. 
 
 Value of principal farm products of the United States. 
 
 
 1859. 
 
 1879. 
 
 1889. 
 
 Products. 
 
 Per 
 cent. 
 
 Total value. 
 
 Per 
 cent. 
 
 Total value. 
 
 Per 
 
 cent. 
 
 Total value. 
 
 Meats 
 
 Corn 
 
 Hay 
 
 Dairy products . . 
 
 Wheat 
 
 Cotton 
 
 Poultry 
 
 Other products (a) 
 
 17.9 
 21.6 
 
 9.1 
 14.4 
 
 7.5 
 12.6 
 
 4.6 
 12.4 
 
 $300,000,000 
 360,680,878 
 152,671,168 
 240,400,580 
 124,635,545 
 211,516,625 
 75,000,000 
 206,639,527 
 
 22.1 
 19.2 
 11.3 
 10.8 
 12 
 
 7.5 
 
 5 
 12.1 
 
 $800,000,000 
 694,818,304 
 409,505,783 
 391,131,618 
 436,968,463 
 271,636,121 
 180,000,000 
 440,438,353 
 
 23.9 
 
 15,9 
 
 14 
 
 11 
 9.1 
 8.2 
 5 3 
 
 12.6 
 
 $900,000,000 
 597,918,829 
 526,682,062 
 411,976,522 
 342,491,707 
 807,008,114 
 200,000,000 
 472,492,249 
 
 Grand total . . 
 
 100 
 
 $1,671,544,323 
 
 100 
 
 $3,624,498,642 
 
 100 
 
 $3,758,519,483 
 
 a "Other products" include barley, buckwheat, iiax fiber, flaxseed, hemp, 
 hops, Irish potatoes, leaf tobacco, maple sirup, maple sugar, oats, rice, i-ye, 
 sorghum molasses, sweet potatoes, and wool. 
 
 But it is not so much in the amount of dairy 
 product manufactured as in the way the business is 
 done that the dairy industry shows its most remarka- 
 ble advances. Up to 1850 the whole dairy output 
 was produced, manufactured, and marketed from in- 
 dividual farms. Since then the introduction and 
 wonderful growth of associated dairying, or the fac- 
 tory system, has taken place, and this period has 
 also witnessed the introduction of so many and so 
 varied machines and utensils that the dairy practice 
 of forty or even twenty years ago is entirely rev- 
 olutionized in the methods of to-day. But while 
 associated dairying has made rapid strides, both in 
 butter and cheese making, it is only in cheese 
 making that the factory system can be said to have 
 at all supplanted private dairying. In 1890 only 
 a little more than 7 per cent of all the cheese 
 produced was made outside of factories; while in the 
 
Butter and Cheese Factories. 251 
 
 same year, of the 1,205,508,384 pounds of butter 
 made in the country, only 181,284,916 pounds, or 
 about 15 per cent, was made in factories. 
 
 Development of the factory system. — Associated 
 dairying, or the manufacture of the milk of several 
 patrons at one place, under the eye of a single 
 person, was at first limited wholly to cheese making. 
 The system may be said to have been inaugurated 
 by Jesse Williams, in Oneida county, N. Y., when 
 in 1851 he began the manufacture of milk, produced 
 by himself and several sons located on farms near 
 by, into cheese under his immediate supervision. 
 From this beginning the number of cheese factories 
 increased, slowly at first but afterward more rapidly, 
 until in 1870 there were in operation 1,313 cheese 
 factories. Up to this time butter factories were un- 
 known, but within a few years began to be rapidly 
 established, and in 1890 there were of both butter 
 and cheese factories 4,712. Ten states — New York, 
 Wisconsin, Iowa, Ohio, Pennsylvania, Illinois, Ver- 
 mont, Minnesota, Michigan and Kansas, in the order 
 named — contained nearly 90 per cent of all the fac- 
 tories. Of these there were in New York 1,387, 
 in Wisconsin 966, and in Iowa 500, or nearly 60 
 per cent of the whole. 
 
 When the first butter factories or creameries, as 
 they are more generally called, were established, the 
 milk of the several patrons was drawn to the fac- 
 tory, set in deep cans, usually surrounded by running 
 water, and afterward skimmed and churned. After 
 a time the gathered -cream system was introduced. 
 
252 Milk and Its Products. 
 
 Under this system the cream was raised upon the farm, 
 usually by a cold deep -setting process, and the repre- 
 sentative of the creamery, visiting the different farms, 
 skimmed the cream, and left the skimmed milk upon 
 the farm. Later on, during the decade beginning in 
 1880, the centrifugal separator was introduced, and at 
 the present time by far the larger number of but- 
 ter factories are operated upon this system. As be- 
 tween the factory system or the private dairy in the 
 manufacture of dairy products, both have their ad- 
 vantages and disadvantages. The advantages of the 
 factory system are so great that practically all of the 
 cheese is made in this way, the small amount made 
 upon farms and in private dairies being almost 
 wholly made for domestic or strictly local consump- 
 tion. These advantages in the main are the saving 
 of labor and the greater uniformity of product. It 
 requires no more time and but slightly more labor 
 to make six thousand pounds of milk into cheese 
 than six hundred. Few private dairies produce more 
 than the latter amount, so that the combination of 
 ten men in a factory will result in saving the labor 
 of at least five men in the manufacture of the pro- 
 duct. Then the cost of building the proper curing 
 room is much less under the factory system than in 
 the private dairy. Conditions of temperature and 
 moisture can readily be secured for a large amount 
 of cheese cured together, that would practically be im- 
 possible if the same amount of cheese was distrib- 
 uted in ten or a dozen parcels and cured separately. 
 In associated butter making, while the same ad- 
 
Condensed Milk. 253 
 
 vantages hold true as in cheese making, they do not 
 manifest themselves to the same degree. There is un- 
 doubtedly a considerable saving of labor and a vastlj" 
 more uniform product where the milk of many patrons 
 is manufactured into butter in a well equipped 
 creamery under skilful supervision, but it is scarcely' 
 possible for a creamery handling the milk of many 
 cows, scattered over a wide area and under the care 
 of many persons, to make butter of so uniformly fine 
 quality as is possible where not only the milk, from 
 the time it is drawn until the finished product is 
 sent to market, but the care and food of the cows 
 as well, are under the same skilful supervision. 
 One of the chief advantages of both the cheese and 
 butter factory system is that it removes from the 
 farm, and particularly from the farm home, a large 
 amount of drudgery that in far too many cases fell 
 upon those least able to bear it, the women of the 
 household ; so that while the butter of the very high- 
 est quality will probably for many years to come be 
 made in relatively small individual or private dairies 
 upon farms, still the factory system is increasing 
 very rapidly, and will continue to do so until pro- 
 portionately as much butter as cheese is made in 
 factories. 
 
 Condensed milk. — In 1856 a patent was granted 
 to Gail Borden, Jr., on a process for "concentrating 
 sweet milk by evaporation in vacuo, having no sugar 
 or other foreign matter mixed with it." From small 
 beginnings the business has grown to enormous pro- 
 portions, and is still largely in the hands of the 
 
254 Milk and Tfs Prodnrtn. 
 
 descendants of the original patentee. At the present 
 time the condensed product is made both with 
 or without the addition of sugar, and is sold in 
 bulk or in hermetically sealed cans, in which latter 
 form it may be preserved for an indefinite time. 
 By far the larger portion of the product is made 
 with the addition of sugar, and is put up in cans. 
 
 According to Dr. Babcock, in the plain condensed 
 milk the water is reduced to about 59 per cent, the 
 other constituents being increased in proportion, while 
 the sugared product contains about 25 per cent of 
 water and 36 per cent of cane sugar. 
 
 The successful condensation of milk requires that 
 the milk be produced under the best hygienic condi- 
 tions and from the purest and most wholesome foods. 
 Consequently we find among the patrons of condens- 
 ing factories a highly developed state of dairy hus- 
 bandry. 
 
 Dairy legislation. — Dairy legislation in the United 
 States has had two main objects. First, to secure 
 to consumers of milk an unadulterated product. This 
 has resulted in the establishment in many states of 
 arbitrary legal standards for the quality of milk, and 
 in others the passage of general laws prohibiting the 
 adulteration of milk in any way ( See appendix C ) . 
 Still, nearly one -third the states have no laws what- 
 ever in regard to the sale of milk, though most of 
 the large cities in these states have adopted municipal 
 regulations of the same general nature as the state 
 laws. 
 
 The second object of dairy legislation has been to 
 
Dairy Legislation. 255 
 
 guarantee the quality of a dairy product or to pre- 
 vent the sale of a spurious product for a genuine one. 
 The introduction of the manufacture of artificial but- 
 ter or oleomargarine has led to both national and state 
 regulation. The manufacture of oleomargarine, and 
 particularly its sale as genuine butter, caused a great 
 injury to the manufacturers of the genuine product, 
 both in the sale of their goods and the prices re- 
 ceived for the same. .The state of New York was 
 one of the first, if not the very first, to enact regu- 
 lations controlling the sale of the imitation product, 
 and in 1884 passed a law prohibiting the manufac- 
 ture and sale of imitation butter within the limits of 
 the state. This law was the subject of much litiga- 
 tion, but has been upheld by the state and national 
 courts. It has been pretty thoroughly enforced, and 
 is still in operatiqn. In 1886 the National Govern; 
 ment passed a law imposing an income tax of two 
 cents per pound upon all imitation butter made in 
 the country, and levying special license taxes upon 
 those engaged in its manufacture and sale. This has 
 resulted in a measurable control of the product, and 
 with the supplemental laws that have been passed in 
 a large number of the states the matter is now under 
 careful and strict regulation. These laws have not 
 resulted, as was fondly hoped by many dairymen, in 
 absolutely stopping the manufacture of imitation but- 
 ter, but have resulted in a great improvement in the 
 quality of the imitation goods and in securing inno- 
 cent purchasers against fraud in palming oif upon 
 them a spurious for a genuine article. At the same 
 
256 Milk and Its Products. 
 
 time, the cheaper imitation butter has crowded out of 
 the market the poorer grades of genuine butter, and 
 so improved the general average quality of genuine 
 butter. 
 
 More recently the manufacture of so-called filled 
 cheese has been regulated in the same way, by the 
 passage by the National Congress, in 1896, of a 
 law similar to the oleomargarine act, placing a rev- 
 enue tax upon all filled cheese manufactured, and a 
 license tax upon the manufacturers and dealers. 
 This filled cheese is made from skimmed milk, to 
 which has been added a certain amount of neutral 
 animal fat. 
 
 Within the past twenty years the practice of mak- 
 ing cheese from skimmed or partially skimmed milk 
 has spread widely throughout the United States. The 
 result has been that the reputation of American cheese 
 has greatly fallen in the market, both abroad and at 
 home. A remedy has been sought by the passage in 
 several states, notably New York and Wisconsin, of 
 laws authorizing the use, on cheese made from whole 
 milk, of "State Brands" guaranteeing the quality of 
 cheese so branded. While cheese -makers were at 
 first not inclined to take advantage of these laws, 
 the " State Brands ' ' are now extensively used with 
 very gratifying results as to the reputation of cheese 
 so branded in the general markets. 
 
 Eecently legislative control has been sought con- 
 corning still another product. A large business 
 has grown up in gathering together, usually from 
 country merchants who have taken the goods in 
 
"Process" Butter. 257 
 
 trade, large amounts of poorly made butter and 
 butter that has been spoiled or partially spoiled. 
 The butter so collected is all melted up together, 
 the solid impurities filtered out and the fat clarified 
 by various processes that are kept more or less 
 secret. The clarified fat is then churned with fresh 
 skimmed milk and the resulting butter colored, 
 salted and worked in the usual way. In some cases 
 the better grades of butter collected from country 
 stores are merely reworked and uniformly colored. 
 All such butter, whatever the treatment it has 
 received, is known as renovated or process butter, 
 and is sold under the names "factory" and "imita- 
 tion creamery." It is very much improved over the 
 original butter from which it was prepared, which 
 is often entirely unsalable as butter, but it is dis- 
 tinctly inferior to the better grades of fresh butter 
 and injures their sale to a greater or less extent. 
 For this reason several states have passed laws 
 requiring that all butter that has been treated as 
 described shall be distinctly branded "Renovated" 
 butter. 
 
 Dairy markets. — In no one particular has the dairy 
 industry developed in recent years more than in the 
 line of production throughout the year. Formerly 
 almost the whole product was made during the warm 
 months. This is measurably so still in the case of 
 cheese, but the demand has been constantly increas- 
 ing for fresh butter the year round, and at the pres- 
 ent time a fairly large proportion of the whole output 
 is made during the winter months, the fresh butter 
 
 Q 
 
258 Milk and Its Products. 
 
 commanding anywhere from two to ten cents per 
 pound more than equally good butter that has been 
 held in storage for several months. Very recently, 
 with improvements in the methods of refrigeration 
 and cold storage, the price of stored butter of the 
 highest quality is reaching nearer to that of the 
 fresh made goods, but the best consumers still con- 
 tinue to call for a fresh article. 
 
APPENDIX. 
 
 A. USEFUL RULES AND TESTS. 
 
 Comparison of Thermometer Scales. 
 
 Centigrade Scale — Freezing point of water = 
 Boiling point of water = 100 
 
 Difference 100 degrees. 
 Fahrenheit Scale — Freezing point of water = 32 
 Boiling point of water = 212 
 
 Difference 180 degrees. 
 100 degrees C. = 180 degrees F. 
 5 " = 9 " 
 
 To Change Degrees Centigrade to Equivalent Degrees 
 Fahrenheit. 
 
 Multiply by f and add. 32; e. g.: 65° C. X f = 117 + 32 = 
 9° F. 
 
 To Change Degrees Fahrenheit to Equivalent Degrees 
 Centigrade. 
 
 Subtract 32 and multiply by f ; «. g. . 98° F. — 32 = 66 X 5 
 = 37°— C. 
 
 To Find the Specific Gravity by the "Board of Health" 
 Lactometer. 
 
 Multiply the reading by .29, divide by 1,000, and add 1.; e. g.. Ob- 
 served reading, 94 X -29 = 27.26-7- 1,000 = . 02726 + 1. = 1.027+ specific 
 gravity. 
 
260 Milk and Its Products. 
 
 To Change "Board of Health" Lactometer Degrees to 
 Equivalent Qubvenne Degrees. 
 
 Multiply the "Board of Health" reading by .29; e. g.: "Board 
 of Health " reading, 105 X .29 = 30.45 = 30+ Quevenne reading. 
 
 To Change Qubvenne Lactometer Degrees to Equivalent 
 "Board of Health" Degrees. 
 
 Divide the observed Quevenne reading by .29; e. g.: Quevenne 
 reading, 34 -=- .29 = 117.+ ordinary or "Board of Health" reading. 
 
 Temperature Correction for Lactometer. 
 
 For Quevenne lactometer, .1 lactometer degree for each degree of 
 temperature F. 
 
 For ordinary or "Board of Health" lactometer, 1 lactometer degree 
 for each 3 degrees of temperature F. 
 
 To be added If the temperature is higher, or subtracted if it is lower 
 than the standard of the lactometer. 
 
 To be used only when the temperature variation is less than 10 
 degrees from the standard of the lactometer. 
 
 To Estimate Solids Not Fat, and Total Solids, from the 
 Specific Gravity and Per Cent op Fat. 
 
 The following formulas may be used : 
 
 Babcock (1) S = Il+jU 
 ' 3.8 
 
 Babcock (2) S = ^ + .2 f 
 
 4 ^ 
 
 Richmond (3) T = Ji + ®-J- + .14 
 4 5 
 
 In the above L = corrected Quevenne lactometer reading, f = per 
 cent of fat, S = solids not fat ; T = total solids ; solids not fat + 
 fat = total solids. 
 
 To apply the above formulse, if the percentage of fat is 4.2 and 
 the liMStometer reading at 60° F. is 32, then 
 
 (11 S = ^+ •'^ ^ S = 32 + .7 (4.2) 
 3.8 ' 3.8 
 
 .7 of 4.2 = 2.94 + 32 = 34.94 -~ 3.8 = 9.19 = solids not fat. 
 9.19 + 4.2 = 13.39 = total solids. 
 
Useful Bules and Tests. 261 
 
 (2) S = 4^ + .2 f, S = -§?- + .2 (4.2) 
 
 i 4 
 
 32 -;- 4 = 8, .2 (4.2) = .84, 8 + .84 = 8.84 = solids not fat. 
 8.84 4- 4.2 = 13.04 = total solids. 
 
 (3) T = Jl + £1 + .14, T = 3^- + " '*-^> + .14 
 
 4^5^ 4^5 
 
 32 -=- 4 = 8, 6 X 4.2 = 25.2 -^ 5 = 5.04. 
 8 + 5.04 + .14 = 13.18 = total solids. 
 
 Litmus Test. 
 A method of determining whether a liquid Is acid or alkaline. 
 In acid solutions, blue litmus turns red. 
 In alkaline solutions, red litmus turns blue. 
 
 Phenolphthalein Test. 
 
 A method of determining whether a liquid is acid or alkaline. 
 
 In acid solutions, if phenolphthalein is added no change in color 
 is produced. 
 
 In alkaline solutions, if phenolphthalein is added the liquid turns 
 pink. 
 
 To Detekmine the Percentage of Lactic Acid in Milk by the 
 Use op Decinormal Alkali, or Parrington's Alkaline Tablets. 
 
 Each c. c. decinormal alkali neutralizes .009 grams lactic acid. 
 Therefore, multiply the number of u. u. decinormal alkali used by 
 .009 and divide the product by the number of grams of milk taken. 
 (Grams = c. c. X 1.032); e. g.. 20 e. c. of milk require 9 c. c. deci- 
 normal alkali to neutralize the acid. The per cent of acid is — 
 
 .009 X 9 = .081 grams lactic acid. 
 
 .081 -f- 20.64 = .0039, or .39 %. 
 
 Each alkaline tablet = 3.8 c. c. decinormal alkali. Each tablet 
 is dissolved in 10 c. c. water. Each c. c. tablet solution = .38 
 c. c. decinormal alkali. Therefore, each c. c. tablet solution will 
 neutralize .009 X .38 = .0034 grams lactic acid. Therefore, mul- 
 tiply the number of c. c. of tablet solution used by .0034 and 
 divide by the number of grams of milk taken (grams = i.-. u. X 
 1.032); ». ST..- 
 
 20 c. c. of cream require 35 c. c. of tablet solution to neutralize 
 the acid. The per cent of acid is — 
 
 .0034 X 35 = .119 grams lactic acid. 
 
 119 -^- 20.64 = .0058, or .58%. 
 
262 Milk and Its Products. 
 
 To Determine Lactic Acid, Using 17.6 u. u. of Milk or Cream. 
 
 Instead of determining lactic acid as described above, it is often 
 more convenient to make the tablet solution of such a strength that 
 1 c. c. of the solution will neutralize .01 per cent of lactic acid in the 
 amount of milk or cream taken. Since a 17.6 e. c. pipette is always 
 found where there is i» Babcock testing outfit, 17.6 c. c. is a very 
 convenient assay, as it does not necessitate procuring an additional 
 pipette. If 5 Farrington tablets are dissolved in 97 c. c. of water the 
 solution will be of such a. strength that each c. c. of solution will 
 neutralize .01 per cent of lactic acid in 17.0 r. t. of milk, and the total 
 number of c. c. used will indicate the amount of lactic acid present 
 in hundredths of one per cent ; e. g.: 
 
 5 tablets are dissolved in 97 c. c. water, and 35 c. u. of the solution 
 are required to neutralize the lactic acid in 17.6 c. c. of cream; the 
 percentage of lactic acid present is therefore .35 per cent. 
 
 To Select Milk for Pasteurization. 
 
 Dissolve any convenient number of Farrington alkaline tablets in 
 an equal number of ounces of water. Provide any convenient small 
 measure, and to one measure of milk add two measures of the pre- 
 pared tablet solution. If the milk remains uncolored, it contains 
 more than .2 of 1 per cent of acid, and is too sour to be safely 
 used. If it is colored pink, it contains less than .2 of 1 per cent 
 of acid, and may safely be used for pasteurizing or sterilizing. 
 Or, the tablet solution will be of very nearly the same strength, 
 and may be used in the same way, if 3 tablets are dissolved in 90 
 c. c. of water. 
 
 To Prepare Viscooen for Restoring the Consistency of 
 Pasteurized Cream. 
 
 Two and one-half parts by weight of a good quality of granulated 
 sugar are dissolved in five parts of water, and one part of quick 
 lime gradually slaked in three parts of water. The resulting milk 
 of lime is strained and added to the sugar solution. The mixture 
 should be agitated at frequent intervals, and after two or three 
 hours allowed to settle until the clear liquid can be decanted off. 
 This clear liquid (viscogen) is the part used and should be kept in 
 well - stoppered bottles, as it loses strength and becomes dark-col- 
 ored when exposed to the air. The darkening in color, however 
 does not impair its usefulness. 
 
Useful Rules and Tests. 263 
 
 To Pkepake Artificial '" Starter" or Ferment for Bipenino 
 Milk or Cream. 
 
 Sterilize ten pounds of fresh, sweet skimmed or whole milk at 
 180° F. Cool to 90° F., and add sufficient dry lactic ferment to 
 secure coagulation in twenty-four hours. When coagulated, add this 
 to the extent of, 10 per cent to enough sterilized whole or skimmed 
 milk to make sufficient "starter" for one day's use. Reserve each 
 day enough of this starter to prepare the starter for the next day, 
 and use the remainder for ripening the milk or cream, using for 
 this from 2 to 5 per cent, according to circumstances. Keep the 
 starter as nearly as possible at a uniform temperature of 80° F. The 
 utmost care must be taken that no germs from outside gain access 
 to the starter in any way or at any time. If this is not done, the 
 starter will rapidly deteriorate or become foul ; but with care in 
 sterilizing the milk and utensils it is not difficult to propagate a 
 starter in this way continuously for months without having it con- 
 taminated " with germs of undesirable fermentations. 
 
 To Detect Ordinary Fermentations or "Taints" in Milk. 
 
 Procure as many test tubes one inch in diameter by five inches long 
 as there are samples of milk to be tested, and » suitable rack to hold 
 them in an upright position. Wash and rinse the tubes thoroughly and 
 sterilize them by boiling in water for thirty minutes or by exposure to 
 live steam in a sterilizing oven for fifteen minutes. After sterilizing 
 they may be allowed to drain dry and then should be kept covered till 
 wanted. When wanted for use the tubes should be filled one-half to 
 two-thirds full with the suspected milk, closed with a piece of glass or 
 plug of cotton and placed in the rack in water kept as nearly constant as 
 possible at 100° F. In from three to four hours the samples may be 
 inspected without shaking or stirring. 6aseous fermentations will be 
 manifested by the appearance of bubbles of gas upon the surface or 
 throughout the mass, souring fermentations by coagulation of the milk 
 and putrefactive fermentations or " taints "by various odors manifest to 
 the nose when the covers are removed. The samples should be kept 
 for at least twenty-four hours and examinations made at frequent 
 intervals. 
 
 The Wisconsin Curd Test. 
 
 This test is used for the same purpose as the fermentation test 
 described above, and is made as follows : Procure as many covered 
 
264 Milk and Its Products. 
 
 pint glass jars as there are samples of milk to be tested and clean 
 and sterilize them as described above. Pill each jar two-thirds lull of 
 the milk to be tested, label them plainly and put them up to the neck 
 in a tub or vat of water heated to 98° F. When the milk has reached 
 the temperature of the water add ten drops of rennet extract to each 
 jar, and mix it with the milk by shaking the jar. Allow the jars to 
 stand until the curd is firm and then cut the curd finely with » case 
 knife. When the curd has settled pour off the whey and allow the 
 curd to settle again till a second portion of whey can be removed, 
 The best tests are made when the removal of whey is as complete as 
 possible. The jars containing the curd are then covered and again 
 placed in the tub and the temperature maintained as nearly as pos- 
 sible at 98° P. for six to 12 hours, when they may be examined. A 
 solid, firm curd, without disagreeable odor or flavor, shows that the 
 milk is pure and clean and has been properly handled. Impurities 
 in the different samples are indicated by the presence of small 
 round holes (gas cells) seen in the curd when it is out across with 
 a knife, or by various disagreeable odors that may he detected when 
 the covers to the jars are removed. The apparatus for this test in 
 an improved form is now furnished by most of the dairy supply 
 houses. 
 
 MoNKAD Rennet Test. 
 
 This test is figured and described on page 173. It is used as fol- 
 lows: To determine the ripeness of milk for cheese making, put 
 5 c. c. commercial rennet in a 50 c. c. flask and fill with water to 
 the mark. Put 200 e. c. of milk at 86° P. in a suitable tin cup, and 
 allow it to float in the vat. Add 5 c. c. of the diluted rennet, and 
 note carefully the time required for the first appearance of coagu- 
 lation. The time required will depend upon the amount of milk 
 and rennet used, the strength of the rennet, the temperature and 
 the ripeness of the milk. All except the last remaining constant 
 from day to day, the degree of ripeness is measured by the time 
 required for coagulation. The riper the milk the shorter the time; 
 ordinarily from one and one-half to two minutes will be required. 
 The diluted rennet must be made fresh every day. 
 
 Makschall Rennet Test. 
 
 Por a description and cut of this test, see page 174. Directions for 
 its use: To determine the ripeness of milk for cheese making, fill 
 the vessel to the o mark with milk, add a pipette full of commercial 
 
Useful Rules and Tests. 2fi^ 
 
 rennet, stir quickly, and place in such a position that tBe milk maJH 
 flow freely from the orifice. When the milk ceases to flow, note the 
 number of graduations exposed. The riper the milk the less the 
 number of exposed graduations. 
 
 Hot Ikon Test. 
 
 A test used to indicate the maturity of curd in cheese making. 
 The maturity is usually coincident with the amount of lactic acid 
 present, so that the test is commonly called the hot iron test for 
 acid. 
 
 The test is made by heating a bar of iron just short of redness, 
 or so that it will hiss readily. A mass of curd is squeezed in the 
 hand till all the whey possible is pressed out. The curd is then 
 applied to the iron ; the surface of the curd, melted by the heat, 
 sticks to the iron, and the remainder is carefully and gently pulled 
 away. If the curd is very immature, the melted part readily sep- 
 arates from that not affected by the heat, but when more mature, 
 numerous fine threads of casein are drawn out when the two parts 
 are separated, the length of these threads depending upon the ma- 
 turity of the curd, and commonly measured in terms of acid, thus, 
 K-ineh acid, 2-inch acid, etc. 
 
 To Calibrate or Test the Accuracy of Graduation of 
 Glassware Used in the Babcock Test. 
 
 Observe that the graduations are at equal distances apart. Fill 
 the bottle carefully to the o point with clean rain water, wipe out 
 the neck carefully, and add from a pipette or burette 2 c. c. water. 
 It should fill the bottle exactly to the 10 point. Or, weigh the 
 bottle filled with clean rain water to the o point with delicate bal- 
 ances, fill to the 10 point and weigh again. The difference in weight 
 should be 2 grams. Or, into a dry, empty bottle put 2 c. c. or 
 27.18 grams mercury, insert a tight-fitting plug carefully to the 10 
 point, and invert the bottle ; the mercury should just reach to the 
 o point. The pipette should hold 17.6 grams of water, or 239 
 grams of mercury. Any piece showing a discrepancy of 2 per cent 
 should be discarded. 
 
 To Test Butter or Cheese With the Babcock Test. 
 
 Weigh out on a balance sensitive to .1 gram, from 4 to 8 grams 
 of the substance to be tested. Divide into small pieces and put 
 into an ordinary test bottle, or bottle with detachable neck, with 
 
^6 Milk and Its Products. 
 
 Rbout 10 c. e. of warm water. Add the acid, and complete the test 
 in the ordinary way. The percentage of fat will be found by the 
 following proportion : 
 
 Weight of sample . 18 : : observed reading : per cent of fat ; or 
 
 18_ X observed reading _ ^^^ ^^^^ ^^ j^^. 
 weight of sample 
 e. g. : 4.8 grams of cheese tested, showed a reading of 9.2 per cent 
 fat in the test bottle. The cheese contained : 
 
 ^^ ^ ^-^ = 34.5 per cent fat. 
 4.8 
 
Metric System. 
 
 267 
 
 S. METRIC SYSTEM. 
 
 The meter is the primary unit of length. It is equal to 
 TinjTs'Sffzristh part of the distance measured on a meridian of 
 the earth from the equator to the pole, and equals about 39.37 
 inches. 
 
 
 Measures of Length. 
 
 
 Equivalents. 
 
 Myriamete^ 
 
 
 10,000 meters 
 
 
 6.2187 miles 
 
 Kilometer 
 
 
 1,000 
 
 
 U. 62187 mile, or 
 8280 ft. 10 in. 
 
 Hectometer 
 
 
 100 
 
 
 828 ft. 1 in. 
 
 Dekameter 
 
 
 10 
 
 
 893.7 in. 
 
 Meter 
 
 
 1 meter 
 
 
 39.87 In. 
 
 Decimeter 
 
 
 .1 
 
 
 8.987 in. 
 
 Centimeter 
 
 
 .01 " 
 
 
 .8987 in. 
 
 Millimeter 
 
 
 .001 " 
 
 
 .08987 in. 
 
 Measures of Surface. 
 
 Equivalents. 
 
 Hectare 
 
 Are 
 
 CeDtare 
 
 10,000 sq. meters 
 100 " " 
 1 " meter 
 
 2.471 acres 
 
 119.6 sq. yards 
 
 1550. sq. inches. 
 
 Measueeb Of Capaoixt. 
 
 Equivalents. 
 
 
 Wo. OF 
 LiTEEB. 
 
 CuBio Measure. 
 
 Det Measure. 
 
 Liquid or Wine 
 
 Measukk. 
 
 KUoliter, or Stere 
 
 Hectoliter 
 
 Dekaliter 
 
 Liter 
 
 Deciliter 
 
 Centiliter 
 
 Milliliter 
 
 1000 
 
 100 
 10 
 
 1 
 .1 
 
 .01 
 .001 
 
 1 en. meter 
 
 .1" 
 10 cu. decimeters 
 1 cu. decimeter 
 .1" " 
 10 cu. centimeters 
 .1 cu. centimeter 
 
 1.308 cu. yards 
 
 2 bu. 8.85 pks. 
 
 9.08 quarts 
 .909 quart 
 
 6.1022 cu. inches 
 .6102 cu. incli 
 .061 " " 
 
 264.17 gal. 
 26.417 gal. 
 2.6417 gal. 
 1.0567 qts. 
 .845 gill 
 ,338 fl, oz. 
 .27 fl. dram 
 
268 
 
 Milk and Its Products. 
 
 System op Weights. 
 
 Equivalents. 
 
 
 No. OF Gbams. 
 
 Weight of Water 
 
 AvOIEDUPOIS 
 
 
 Maximum Densitt. 
 
 Weight. 
 
 Millier, or Tonneau 
 
 1,000,000 
 
 1 cu. meter 
 
 2204.6 pounds 
 
 Quintal 
 
 100,000 
 
 1 hectoUter 
 
 220.46 
 
 Myriagram 
 
 10,000 
 
 1 dekaliter 
 
 22.046 " 
 
 Kilogram, or Kilo 
 
 1,000 
 
 1 liter 
 
 2.2046 " 
 
 Hectogram 
 
 100 
 
 1 deciliter 
 
 8.5274 oz. 
 
 Dekagram 
 
 10 
 
 10 cu. centimeters 
 
 .8527 " 
 
 Gram 
 
 1 
 
 1 cu. centimeter 
 
 15.432 grains 
 
 Decigram 
 
 .1 
 
 .1 " 
 
 1.5482 " 
 
 Centigram 
 
 .01 
 
 10 cu. millimeters 
 
 .1548 grain 
 
 Milligram 
 
 .001 
 
 1 *' millimeter 
 
 .0154 " 
 
 Common 
 Measure. 
 
 Equivalents. 
 
 Common 
 Measure. 
 
 Equivalents. 
 
 An inch 
 
 2.54 centimeters 
 
 A cu. yard 
 
 .7646 cu. meter 
 
 A foot 
 
 .3048 meter 
 
 A cord 
 
 3.624 steres 
 
 A yard 
 
 .9144 " 
 
 A liquid qt. 
 
 .9465 liter 
 
 A rod 
 
 5.029 meters 
 
 A gallon 
 
 8.786 Uters 
 
 A mile 
 
 1.6093 kilometers 
 
 A dry qt. 
 
 1.101 " 
 
 A sq. inch 
 
 G.452 sq. centimeters 
 
 A peck 
 
 8.811 " 
 
 A " foot • 
 
 .0929 sq. meter 
 
 A bushel 
 
 35.24 " 
 
 A *' yard. 
 
 .8361 " " 
 
 An oz. avoirdupois 
 
 28.35 grams 
 
 A " rod 
 
 25.29 sq. meters 
 
 A pound " 
 
 .4536 kilogram 
 
 An acre 
 
 .4047 hectare 
 
 A ton 
 
 .9072 tonneau 
 
 A sq. mile 
 
 259 hectares. 
 
 A grain troy 
 
 .0648 gram 
 
 A QU. inch 
 
 16.39 cu. centimeters 
 
 An oz. " 
 
 81.104 grams 
 
 A " foot 
 
 .02832 cu. meter 
 
 A pound *' 
 
 .3732 kilogram 
 
standards for Milk — Dairy Laws. 269 
 
 C. LEGAL STANDARDS FOB MILK—DAIBT LAWS. 
 
 The following states and territories ; viz., Alabama, Arizona, 
 Arkansas, California, Colorado, Delaware, Florida, Louisiana, Missis- 
 sippi, Missouri, Montana, North Dakota, Texas and Wyoming, have 
 established no legal standard. 
 
 The Dominion of Canada, Connecticut, Idaho, Illinois, Indiana, 
 Kansas, Kentucky, Maryland, Nebraska, Nevada, New Mexico, North 
 Carolina, Oklahoma, South Dakota, Tennessee, Utah, Virginia and 
 West Virginia have general laws prohibiting dilution, skimming or 
 other adulteration. 
 
 In the other states the percentage standards are as follows : 
 
 Specific Total 
 
 gravity, solids, 96. Fats, % 
 
 District of Columbia 12.5 3.5 
 
 Georgia 12 3.5 
 
 Iowa 12,5 3 
 
 Maine 12 3 
 
 Massachusetts (Apr. to Aug., inclusive) 12 3 
 
 " (Sept. to Mar. inclusive) 13 3.7 
 
 Michigan 1.029-1.033 12.5 3 
 
 Minnesota 13 3.5 
 
 New Hampshire 13 — 
 
 New Jersey 12 
 
 New York 12 3 
 
 Ohio (May and June) 11.5 
 
 " (July to April, inclusive) 12 3 
 
 Oregon 12 3 
 
 Pennsylvania*...' 1.029-1.033 12.5 3 
 
 Rhode Lsland 12 2.5 
 
 South Carolina 11.5 3 
 
 Vermont (May and June) 12 
 
 (July to April, inclusive).- 12.5 — 
 
 Washington 11 3 
 
 Wisconsin 3 
 
 ft 
 
 The full texts of the national oleomargarine and filled cheese laws 
 are as follows : 
 
 *Applies only to cities of the second and third classes. 
 
270 Milk and Its Products. 
 
 THE OLEOMARGARINE LAW. 
 
 AN ACT defining butter, also imposing a tax upon and regulating the manu- 
 facture, sale, importation and exportation of oleomargarine. 
 
 Be it enacted hy the Senate and Souse of Representatives of the 
 United States of America in Congress assembled. That for the pur- 
 pose of this act the word "butter" shall be understood to mean 
 the food product usually known as butter, and which is made exclu- 
 sively from milk or cream, or both, with or without common salt, 
 and with or without additional coloring matter. 
 
 Section 2. That for the purposes of this act certain manufac- 
 tured substances, certain extracts, and certain mixtures and com- 
 pounds, including such mixtures and compounds with butter, shall 
 be known and designated as " oleomargarine ; " namely : All sub- 
 stances heretofore known as oleomargarine, oleo, oleomargarine oil, 
 butterine, lardine, suine and neutral ; all mixtures and compounds 
 of oleomargarine, oleo, oleomargarine-oil, butterine, lardine, suine, 
 and neutral ; all lard extracts and tallow extracts ; and all mix- 
 tures and compounds of tallow, beef-fat, suet, lard, lard-oil, veg- 
 etable-oil, annatto and other coloring matter, intestinal fat, and offal 
 fat made in imitation or semblance of butter, or when so made 
 calculated or intended to be sold as butter, or for butter. 
 
 Sec. 3. That special taxes are imposed as follows : 
 
 Manufacturers of oleomargarine shall pay six hundred dollars. 
 Every person who manufactures oleomargarine for sale shall be 
 deemed a manufacturer of oleomargarine. 
 
 Wholesale dealers in oleomargarine shall pay four hundred and 
 eighty dollars. Every person who sells or offers for sale oleomar- 
 garine in the original manufacturer's packages shall be deemed a 
 wholesale dealer in oleomargarine. But any manufacturer of oleo- 
 margarine who has given the required bond and paid the required 
 special tax, and who sells only oleomargarine of his own produc- 
 tion, at the place of manufacture, in the original packages to which 
 the tax-paid stamps are afSxed, shall not be required to pay the 
 special tax of a wholesale dealer in oleomargarine on account of 
 such sales. 
 
 Retail dealers in oleomargarine shall pay forty-eight dollars. 
 Every person who sells oleomargarine in less quantities than ten 
 pounds at one time shall be regarded »s a retail dealer in oleo- 
 margarine. And sections thirty-two hundred and thirty two, thirty- 
 two hundred and thirty-three, thirty-two hundred and thirty-four, 
 
Dairy Laws. 271 
 
 thirty-two hundred and thirty-five, thirty-two hundred and thirty- 
 six, thirty-two hundred and thirty-seven, thirty-two hundred and 
 thirty-eight, thirty-two hundred and thirty-nine, thirty-two hundred 
 and forty, thirty-two hundred and forty-one, and thirty-two hundred 
 and forty-three of the Revised Statutes of the United States are, so 
 far as applicable, made to extend to and include and apply to the 
 special taxes imposed by this section, and to the persons upon 
 whom they are imposed. 
 
 Sec. 4. That every person who carries on the business of a 
 manufacturer of oleomargarine without having paid the special tax 
 therefore, as required by law, shall, besides being liable to the 
 payment of the tax, be fined not less than one thousand and not 
 more than five thousand dollars ; and every person who carries on 
 the business of » wholesale dealer in oleomargarine without having 
 paid the special tax therefor, as required by law, shall, besides 
 being liable to the payment of the tax, be fined not less than five 
 hundred nor more than two thousand dollars ; and every person 
 who carries on the business of a retail dealer in oleomargarine 
 without having paid the special tax therefor, as required by law, 
 shall, besides being liable to the payment of the tax, be fined not 
 less than fifty nor more than five hundred dollars for each and 
 every offense. 
 
 Sec. 5. That every manufacturer of oleomargarine shall file with 
 the collector of internal revenue of the district in which his man- 
 ufactory is located such notices, inventories and bonds, shall keep 
 such books and render such returns of material and products, 
 shall put up such signs and affix such number to his factory, 
 and conduct his business under such surveillance of officers and 
 agents, as the Commissioner of Internal Revenue, with the appro- 
 val of the Secretary of the Treasury, may, by regulation, require. 
 But the bond required of such manufacturer shall be with sureties 
 satisfactory to the collector of internal revenue, and in a penal 
 sum of not less than five thousand dollars ; and the sum of said 
 bond may be increased from time to time and additional sureties re- 
 quired at the discretion of the collector, or under instructions of 
 the Commissioner of Internal Revenue. 
 
 Sec. 6. That all oleomargarine shall be packed by the manu- 
 facturer thereof in firkins, tubs or other wooden packages, not be- 
 fore used for that purpose, each containing not less than ten 
 pounds, and marked, stamped and branded as the Commissioner of 
 Internal Revenue, with the approval of the Secretary of the Tr'eas- 
 
272 Milk and Its Products. 
 
 ury, shall prescribe ; and all sales made by manufacturers of oleo- 
 margarine and wholesale dealers in oleomargarine shall be in 
 original stamped packages. Retail dealers in oleomargarine must 
 sell only from original stamped packages, in quantities not 
 exceeding ten pounds, and shall pack the oleomargarine sold by 
 them in suitable wooden or paper packages, which shall be marked 
 and branded as the Commissioner of Internal Revenue, with the 
 approval of the Secretary of the Treasury, shall prescribe. Every 
 person who knowingly sells or offers for sale, or delivers or offers 
 to deliver, any oleomargarine in any other form than in new wooden 
 or paper packages as above described, or who packs in any pack- 
 age any oleomargarine in any manner contrary to law, or who 
 falsely brands any package or affixes a stamp on any package 
 denoting a less amount of tax than that required by law, shall 
 be fined for each offense not more than one thousand dollars and 
 be imprisoned not more than two years. 
 
 Sec. 7. That every manufacturer of oleomargarine shall securely 
 affix, by pasting on each package containing oleomargarine manufac- 
 tured by him, a label on which shall be printed, besides the number 
 of the manufactory, and the district and state in which it is situ- 
 ated, these words "Notice. — The manufacturer of the oleomargarine 
 herein contained has complied with all the requirements of law. 
 Every person is cautioned not to use either this package again or 
 the stamp thereon again, nor to remove the contents of this pack- 
 age without destroying said stamp, under the penalty provided by 
 law in such cases." Every manufacturer of oleomargarine who 
 neglects to affix such label to any package containing oleomarga- 
 rine made by him, or sold or offered for sale by or for him, and 
 every person who removes any such label so affixed from any such 
 package, shall be fined fifty dollars for each package in respect to 
 which such offense is committed. 
 
 Sec. 8. That upon oleomargarine which shall be manufactured 
 and sold, or removed for consumption or use, there shall be assessed 
 and collected a tax of two cents per pound, to be paid by the 
 manufacturer thereof ; and any fractional part of a pound in a 
 package shall be taxed as a pound. The tax levied by this sec- 
 tion shall be represented by coupon stamps ; and the provisions of 
 existing laws governing the engraving, issue, sale, accountability, 
 effacement, and destruction of stamps relating to tobacco and snuff, 
 as far as applicable, are hereby made to apply to stamps provided 
 for by this section. 
 
Dairy Laws. 273 
 
 Sec. 9. That whenever any manufacturer of oleomargarine sells, 
 or removes for sale or consumption, any oleomargarine upon which 
 the tax Is required to be paid by stamps, without the' use of the 
 proper stamps, it shall be the duty of the Commissioner of Internal 
 Revenue, within a period of not more than two years after such 
 sale or removal, upon satisfactory proof, to estimate the amount 
 of tax which has been omitted to be paid, and to make an assess- 
 ment therefor and certify the same to the collector. The tax so 
 assessed shall be in addition to the penalties imposed by law for 
 such sale or removal. 
 
 Sec. 10. That all oleomargarine imported from foreign countries 
 shall, in addition to any import duty imposed on the same, pay an 
 internal revenue tax of fifteen cents per pound, such tax to be 
 represented by coupon stamps as in the case of oleomargarine 
 manufactured in the United States. The stamps shall be affixed 
 and canceled by the owner or importer of the oleomargarine while 
 it is in the custody of the proper custom-house officers ; and the 
 oleomargarine shall not pass out of the custody of said officers 
 until the stamps have been soi affixed and canceled, but shall be put 
 up in wooden packages, each containing not less than ten pounds, 
 as prescribed in this act for oleomargarine manufactured in the 
 United States, before the stamps are affixed ; and the owner or 
 importer of such oleomargarine shall be liable to all the penal 
 provisions of this act prescribed for manufacturers of oleomargarine 
 manufactured in the United States. Whenever it is necessary to 
 take any oleomargarine so imported to any place other than the 
 public stores of the United States for the purpose of affixing and can- 
 celing such stamps, the collector of customs of the port where such 
 oleomargarine is entered shall designate a bonded warehouse to which 
 it shall be taken, under the control of such customs officer as such 
 collector may direct ; and every officer of customs who permits 
 any such oleomargarine to pass out of his custody or control with- 
 out compliance by the owner or importer thereof with the provi- 
 sions of this section relating thereto, shall be guilty of a misde- 
 meanor, and shall be fined not less than one thousand dollars nor 
 more than five thousand dollars, and imprisoned not less than six 
 months nor more than three years. Every person who sells or 
 offers for sale any imported oleomargarine, or oleomargarine pur- 
 porting or claimed to have been imported, not put up in pack- 
 ages and stamped as provided by this act, shall be fined not less 
 than five hundred dollars nor more than five thousand dollars. 
 
274 Milk and Its Products. 
 
 and be imprisoned not less than six months nor more than two 
 years. 
 
 Sec. 11. That every person who knowingly purchases or receives 
 for sale any oleomargarine which has not been branded or stamped 
 according to law shall be liable to a penalty of fifty dollars for 
 each such ofEense. 
 
 Sec. 12. That every person who knowingly purchases or receives 
 for sale any oleomargarine from any manufacturer who has not 
 paid the special tax shall be liable for each offense to a penalty 
 of one hundred dollars, and to a forfeiture of all articles so pur- 
 chased or received, or of the full value thereof. 
 
 Sec. 13. That whenever any stamped package containing oleomar- 
 garine is emptied, it shall be the duty of the person in whose hands 
 the same is, to destroy utterly the stamps thereon ; and any per- 
 son who willfully neglects or refuses so to do shall for each such 
 ofEense be fined not exceeding fifty dollars, and imprisoned not less 
 than ten days nor more than six months. And any person who 
 fraudulently gives away or accepts from another, or who sells, buys, 
 or uses for packing oleomargarine, any such stamped package, shall 
 for each such offense be fined not exceeding one hundred dollars, 
 and be imprisoned not more than one year. Any revenue officer 
 may destroy any emptied oleomargarine package upon which the tax- 
 paid stamp is found. 
 
 Sec. 14. That there shall be in the ofiice of the Commissioner 
 of Internal Revenue an analytical chemist and a microscopist, who 
 shall each be appointed by the Secretary of the Treasury, and shall 
 each receive a salary of two thousand five hundred dollars per an- 
 num ; and the Commissioner of Internal Revenue may, whenever in 
 his judgment the necessities of the service so require, employ chem- 
 ists and microscopists, to be paid such compensation as he may 
 deem proper, not exceeding in the aggregate any appropriation made 
 for that purpose. And such Commissioner is authorized to decide 
 what substances, extracts, mixtures or compounds which may be sub- 
 mitted for his inspection in contested cases are to be taxed under 
 this act ; and his decision in matters of taxation under this act 
 shall be final. The Commissioner may also decide whether any 
 substance made in imitation or semblance of butter, and intended 
 for human consumption, contains ingredients deleterious to the pub- 
 lic health ; but in case of doubt or contest his decisions in this 
 class of cases may be appealed from to a board hereby constituted 
 for the purpose, > and composed of the Surgeon-General of the Army, 
 
Dairy Laws. 275 
 
 the Surgeon-General of the Navy, and the Secretary of Agricul- 
 ture ; and the decisions of this board shall be final in the prem- 
 ises. 
 
 Sec. 15. That all packages of oleomargarine subject to tax under 
 this act that shall be found without stamps or marks as herein pro- 
 vided, and all oleomargarine intended for human consumption which 
 contains ingredients adjudged, as hereinbefore provided, to be del- 
 eterious to the public health, shall be forfeited to the United States. 
 Any person who shall willfully remove or deface the stamps, marks, 
 or brands on package containing oleomargarine taxed as provided 
 herein shall be guilty of a misdemeanor, and shall be punished by 
 a fine of not less than one hundred dollars nor more than two thou- 
 sand dollars, and by imprisonment for not less than thirty days nor 
 more than six months. 
 
 Seo. 16. That oleomargarine may be removed from the place of 
 manufacture for export to a foreign country without payment of 
 tax or afiixing stamps thereto, under such regulations and the fil- 
 ing of such bonds and other security as the Commissioner of In- 
 ternal Revenue, with the approval of the Secretary of the Treas- 
 ury, may prescribe. Every person who shall export oleomargarine 
 shall brand upon every tub, firkin, or other package containing such 
 article the word " oleomargarine," in plain Roman letters not less 
 than one-half inch square. 
 
 Sec. 17. That whenever any person engaged in carrying on the 
 business of manufacturing oleomargarine defrauds, or attempts to 
 defraud, the United States of the tax on the oleomargarine pro- 
 duced by him, or any part thereof, he shall forfeit the factory and 
 manufacturing apparatus used by him, and all oleomargarine and 
 all raw material for the production of oleomargarine found in the 
 factory and on the factory premises, and shall be fined not less than 
 five hundred dollars, nor more than five thousand dollars, and be 
 imprisoned not less than six months nor more than three years. 
 
 Sec. 18. That if any manufacturer of oleomargarine, any dealer 
 therein, or any importer or exporter thereof shall knowingly or 
 willfully omit, neglect or refuse to' do, or cause to be done, any of 
 the things required by law in the carrying on or conducting of his 
 business, or shall do anything by this act prohibited, if there be 
 no specific penalty or punishment Imposed by any other section of 
 this act for the neglecting, omitting, or refusing to do, or for the 
 doing or causing to be done, the thing required or prohibited, he 
 shall pay a penalty of one thousand dollars ; and if the person so 
 
276 Milk and Its Products. 
 
 offending be the manufacturer of or a wholesale dealer in oleomar- 
 garine, all the oleomargarine owned by him, or in which he has 
 any interest as owner, shall be forfeited to the United States. 
 
 Sec. 19. That all fines, penalties, and forfeitures imposed by 
 this act may be recovered in any court of competent jurisdiction. 
 
 Sec. 20. That the Commissioner of Internal Revenue, with the 
 approval of the Secretary of the Treasury, may make all needful reg- 
 ulations for the carrying into effect of this act. 
 
 Sec. 21. That this act shall go into effect on the ninetieth day 
 after its passage ; and all wooden packages containing ten or more 
 pounds of oleomargarine found on the premises of any dealer on 
 or after the ninetieth day succeeding the date of the passage of 
 this act shall be deemed to be taxable under section eight of this 
 act, and shall be taxed, and shall have af&xed thereto the stamps, 
 marks, and brands required by this act or by regulations made 
 pursuant to this act ; and for the purposes of securing the af&xing 
 of the stamps, marks, and brands required by this act, the oleomar- 
 garine shall be regarded as having been manufactured and sold, or 
 removed from the manufactory for consumption or use, on or after 
 the day this act takes effect ; and such stock on hand at the time 
 of the taking effect of this act may be stamped, marked, and 
 branded under special regulations of the Commissioner of Internal 
 Revenue, approved by the Secretary of the Treasury ; and the Com- 
 missioner of Internal Revenue may authorize the holder of such 
 packages to mark and brand the same and to afiix thereto the pro- 
 per tax-paid stamps. 
 
 Approved August 2, 1886. 
 
 THE FILLED CHEESE LAW. 
 
 AN ACT defining cheese, and also imposing a tax upon ^and regulating the 
 manufacture, sale, importation and exportation of "filled cheese." 
 
 Be it enacted by the Senate and Mouse of Representatives of the 
 United States of America in Congress assembled. That for the pur- 
 poses of this act, the word " cheese " shall be understood to mean 
 the food product known as cheese, and which is made from milk 
 or cream, and without the addition of butter, or any animal, vege- 
 table, or other oils or fats foreign to such milk or cream, with or 
 without additional coloring matter. 
 
Dairy Laws. " 277 
 
 Section 2. That for the purposes of this act certain substances 
 and compounds shall be known and designated as " filled cheese," 
 namely: All substances made of milk or skimmed milk, with the 
 admixture of butter, animal oils or fats, vegetable or any other oils, 
 or compounds foreign to such milk, and made in imitation or sem- 
 blance of cheese. 
 
 Sec. 3. That special taxes are imposed as follows; 
 
 Manufacturers of filled cheese shall pay four hundred dollars for 
 each and every factory per annum. Every person, firm, or corpora- 
 tion who manufactures filled cheese for sale shall be deemed a man- 
 ufacturer of filled cheese. Wholesale dealers in filled cheese shall pay 
 two hundred and fifty dollars per annum. Every person, firm, or cor- 
 poration who sells, or offers for sale filled cheese in the original man- 
 ufacturer's packages for resale, or to retail dealers as hereinafter de- 
 fined, shall be deemed a wholesale dealer in filled cheese. But any 
 manufacturer of filled cheese who has given the required bond and 
 paid the required special tax, and who sells only filled cheese of his 
 own production, at the place of manufacture, in the original pack- 
 ages, to which the tax-paid stamps are affixed, shall not be required 
 to pay the special tax of a wholesale dealer in filled cheese on ac- 
 count of such sales. 
 
 Retail dealers in filled cheese shall pay twelve dollars per annum. 
 Every person who sells filled cheese at retail, not for resale, and 
 for actual consumption, shall be regarded as a retail dealer in filled 
 cheese, and sections thirty-two hundred and thirty-two, thirty-two 
 hundred and thirty-three, thirty-two hundred and thirty-four, thirty- 
 two hundred and thirty-five, thirty-two hundred and thirty-six, thirty- 
 two hundred and thirty-seven, thirty-two hundred and thirty-eight, 
 thirty-two hundred and thirty-nine, thirty-two hundred and forty, thir- 
 ty-two hundred and forty-one, thirty-two hundred and forty-three of 
 the Revised Statutes of the United States are, so far as applicable, 
 made to extend to and include and apply to the special taxes im- 
 posed by this section and to the persons, firms, or corporations upon 
 whom they are imposed: Provided, That all special taxes under this 
 act shall become due on the first day of July in every year, or on 
 commencing any manufacture, trade, or business on which said tax 
 is imposed. In the latter case the tax shall be reckoned propor- 
 tionately from the first day of the month in which the liability to 
 the special tax commences to the first day of July following. 
 
 Sec. 4 That every person, firm or corporation who carries on the 
 business of a manufacturer of filled cheese without having paid the 
 
278 Milh and Its Products. 
 
 special tax therefor, as required by law, shall, besides being liable 
 to ihe payment of the tax, be fined not less than four hundred dol- 
 lars and not more than three thousand dollars; and every person, 
 firm, or corporation who carries on the business of a wholesale dealer 
 in filled cheese without having paid the special tax therefor, as re- 
 quired by law, shall, besides being liable to the payment of the tax, 
 be fined not less than two hundred and fifty dollars, nor more than 
 one thousand dollars ; and every person, firm, or corporation, who car- 
 ries on the business of a retail dealer in filled cheese without having 
 paid the special tax therefor, as required by law, shall, besides being 
 liable for the payment of the tax, be fined not less than forty nor 
 more than five hundred dollars for each and every offense. 
 
 Sec. 5. That every manufacturer of filled cheese shall file with 
 the collector of internal revenue of the district in which his man- 
 ufactory is located, such notices, inventories, and bonds, shall keep 
 such boolis and render such returns of materials and products, shall 
 put up such signs and affix such number to his factory, and con- 
 duct his business under such surveillance of officers and agents as 
 the Commissioner of Internal Revenue, with the approval of the 
 Secretary of the Treasury, may by regulation require. But the bond 
 required of such manufacturer shall be with sureties satisfactory to 
 the collector of internal revenue, and in a penal sum of not less than 
 five thousand dollars; and the amount of said bond may be in- 
 creased from time to time, and additional sureties required, at the 
 discretion of the collector or under instructions of the Commissioner 
 of Internal Revenue. Any manufacturer of filled cheese who fails 
 to comply with the provisions of this section, or with the regula- 
 tions herein authorized, shall be deemed guilty of a misdemeanor, 
 and upon conviction thereof shall be fined not less than five hun- 
 dred nor more than one thousand dollars. 
 
 Seo. 6. That filled cheese shall be packed by the manufacturers 
 in wooden packages only, not before used for that purpose, and 
 marked, stamped, and branded with the words " filled cheese," in 
 black-faced letters not less than two inches in length, in a circle 
 in the center of the top and bottom of the cheese; and in black- 
 faced letters of not less than two inches in length in line from 
 the top to the bottom of the cheese, on the side in four places 
 equidistant from each other ; and the package containing such cheese 
 shall be marked in the same manner, and in the same number of 
 places, and in the same description of letters as above provided for 
 the marking of the cheese; and all sales or consignments made by 
 
Dairy Laws. 279 
 
 manufacturers of filled cheese to wholesale dealers in filled cheese 
 or to exporters of filled cheese shall be in original stamped pack- 
 ages. Retail dealers in filled cheese shall sell only from original 
 stamped packages, and shall pack the filled cheese, when sold, in 
 suitable wooden or paper packages which shall be marked and branded 
 in accordance with the rules and regulations to be prescribed by the 
 Commissioner of Internal Revenue, with the approval of the Secre- 
 tary of the Treasury. Every person who knowingly sells or offers 
 to sell, or delivers or offers to deliver, filled cheese in any other 
 form than in new wooden or paper packages, marked and branded 
 as hereinbefore provided and as above described, or who packs in any 
 package or packages filled cheese in any manner contrary to law, 
 or who falsely brands any package or affixes a stamp on any pack- 
 age denoting » less amount of tax than that required by law, shall 
 upon conviction thereof be fined for each and every offense not 
 less than fifty dollars and not more than five hundred dollars, 
 or be imprisoned not less than thirty days nor more than one 
 year. 
 
 Sec. 7. That all retail and wholesale dealers in filled cheese 
 shall display in a conspicuous place in his or their salesroom a sign 
 bearing the words, " Pilled cheese sold here " in black-faced letters not 
 less than six inches in length, upon a white ground, with the name 
 and number of the revenue district in which his or their business 
 is conducted; and any wholesale or retail dealer in filled cheese 
 who fails or neglects to comply with the provisions of this section 
 shall be deemed guilty of a, misdemeanor, and shall on conviction 
 thereof be fined for each and every offense not less than fifty dol- 
 lars and not more than two hundred dollars. 
 
 Sec. 8. That every manufacturer of filled cheese shall securely 
 affix, by pasting on each package containing filled cheese manufac- 
 tured by him, a label on which shall be printed, besides the num- 
 ber of the manufactory and the district and state in which it is 
 situated, these words: " Notice. — The manufacturer of the filled cheese 
 herein contained has complied with all the requirements of the 
 law. Every person is cautioned not to use either this package 
 again or the stamp thereon again, nor to remove the contents of 
 this package without destroying said stamp, under the penalty pro- 
 vided by law in such cases." Every manufacturer of filled cheese 
 who neglects to affix such label to any package containing filled 
 cheese made by him or sold or offered for sale by or for him, 
 and every person who removes any such label so affixed from any 
 
280 Milk and Its Products. 
 
 fsuch package, shall be fined fifty dollars for each package in re- 
 spect to which such offense is committed. 
 
 Sec. 9. That upon all filled cheese which shall be manufactured 
 there shall be assessed and collected a tax of one cent per pound, 
 to be paid by the manufacturer thereof; and any fractional part of 
 a pound in a package shall be taxed as a pound. The tax levied 
 by this section shall be represented by coupon stamps; and the 
 provisions of existing laws governing the engraving, issue, sale, 
 accountability, effacement, and destruction of stamps relating to 
 tobacco and snuff, as far as applicable, are hereby made to apply 
 to stamps provided for by this section. 
 
 Sec. 10. That whenever any manufacturer of filled cheeese sells 
 or removes for sale or consumption any filled cheese upon which 
 the tax is required to be paid by stamps, without paying such tax, 
 it shall be the duty of the Commissioner of Internal Revenue, 
 within a period of not more than two years after such sale or re- 
 moval, upon satisfactory proof, to estimate the amount of tax which 
 has been omitted to be paid and to make an assessment therefor 
 and certify the same to the collector. The tax so assessed shall be 
 in addition to the penalties imposed by law for such sale or removal. 
 
 Sec. H. That all filled cheese, as herein defined, imported from 
 foreign countries shall, in addition to any import duty imposed on 
 the same, pay an internal revenue tax of eight cents per pound, 
 such tax to be represented by coupon stamps; and such imported 
 filled cheese and the packages containing the same shall be stamped, 
 marked, and branded, as in the case of filled cheese manufactured 
 in the United States. 
 
 Sec. 12. That any person who knowingly purchases or receives 
 for sale any filled cheese which has not been branded or stamped 
 according to law, or which is contained in packages not branded 
 or marked according to law, shall be liable to a penalty of fifty 
 dollars for each such offense. 
 
 Sec. 13. That every person who knowingly purchases or receives 
 for sale any filled cheese from any manufacturer or importer who 
 has not paid the special tax herein provided for shall be liable, 
 for each offense, to a penalty of one hundred dollars, and to a for- 
 feiture of all articles so purchased or received, or of the full value 
 thereof. „ 
 
 Sec. 14. That whenever any stamped package containing filled 
 cheese is emptied it shall be the duty of the person in whose 
 
Dairy Laws. 281 
 
 hands the same is to destroy the stamps thereon; and any person 
 who willfully neglects or refuses so to do shall, for each such 
 offense, be fined not exceeding fifty dollars or imprisoned not less 
 than ten days nor more than six months. 
 
 Seo. 15. That the Commissioner of Internal Revenue is author- 
 ized to have applied scientific tests, and to decide whether any 
 substances used in the manufacture of filled cheese contain ingre- 
 dients deleterious to health. But in case of doubt or contest, his 
 decision in this class of cases may be appealed from to a board 
 hereby constituted for the purpose, and composed of the Surgeon- 
 General of the Army, the Surgeon-General of the Navy, and the 
 Secretary of Agriculture, and the decision of this board shall be 
 final in the premises. 
 
 Sec. 16. That all packages of filled cheese subject to tax under 
 this act that shall be found without stamps or marks as herein 
 provided, and all filled cheese intended for human consumption 
 which contains ingredients adjudged as hereinbefore provided to be 
 deleterious to the public health, shall be forfeited to the United 
 States. 
 
 Sec. 17. That all fines, penalties and forfeitures imposed by this 
 act may be recovered in any court of competent jurisdiction. 
 
 Sec. 18. That the Commissioner of Internal Revenue, with the 
 approval of the Secretary of the Treasury, shall make all need- 
 ful regulations for the carrying into effect the provisions of this 
 act. 
 
 Sec. 19. That this act shall go into effect on the ninetieth day 
 after its passage, and all wooden packages containing ten or more 
 pounds of filled cheese found on the premises of any dealer on 
 and after the ninetieth day succeeding the date of the passage of 
 this act, shall be deemed to be taxable under section nine of this 
 act, and shall be taxed, and shall have affixed thereto the stamps, 
 marks, and brands required by this act or by regulations made 
 pursuant to this act; and for the purpose of securing the af&xing 
 of the stamps, marks, and brands required by this act, the filled 
 cheese shall be regarded as having been manufactured and sold or 
 removed from the manufactory for consumption or use on or after 
 the day this act takes effect; and such stock on hand at the time 
 of the taking effect of this act may be stamped, marked, and branded 
 under special regulations of the Commissioner of Internal Revenue, 
 approved by the Secretary of the Treasury; and the Commissioner 
 
282 Milk and Its Products. 
 
 of Internal Revenue may authorize the holder of such packages to 
 mark and hrand the same and to afftx thereto the proper tax-paid 
 stamps. 
 
 Approved June 6, 1896. 
 
 THE NEW YORK LAW. 
 
 The law of the state of New York is typical of the state laws 
 governing the manufacture, sale, and adulteration of dairy products. 
 It forms Article II. of Chapter XXXIII. of the General Laws; the 
 latter being Chapter 338 of the Laws of 1893, passed April 10th, 
 J893, and is as follows: 
 
 ARTICLE II. 
 
 Dairy Products, 
 
 Sec. 20. Definitions, — The terms butter and cheese, when used 
 in this article, mean the products of the dairy, usually known by 
 those terms, which are manufactured exclusively from pure, una- 
 dulterated milk or cream or both, with or without salt or rennet, 
 and with or without coloring matter or sage. The terms oleomar- 
 garine, butterine, imitation butter or imitation cheese, shall be 
 construed to mean any article or substance in the semblance of 
 butter or cheese not the usual product of the dairy, and not made 
 exclusively of pure and unadulterated milk or cream, or any such 
 article or substance into which any oil, lard or fat not produced 
 from milk or cream enters as a component part, or into which 
 melted butter or butter in any condition or state, or any oil 
 thereof, has been introduced to take the place of cream. The term 
 adulterated milk, when so used, means: 
 
 1. Milk containing more than 88 per centum of water or fluids. 
 
 2. Milk containing less than 12 per centum of milk solids. 
 
 3. Milk containing less than 3 per centum of fats. 
 
 4. Milk drawn from cows within fifteen days before and five 
 days after parturition. 
 
 5. Milk drawn from animals fed on distillery waste, or any sub- 
 stance in a state of fermentation or putrefaction, or on any un- 
 healthy food. 
 
 6. Milk drawn from cows kept in a crowded or unhealthy con- 
 dition. 
 
Dairy Laws. 283 
 
 7. Milk from which any part of the cream has been remoyed. 
 
 8. Milk which has been diluted with water or any other fluid, 
 or to which has been added or into which has been introduced 
 any foreign substance whatever. 
 
 All adulterated milk shall be deemed unclean, unhealthy, impure 
 and unwholesome. The terms pure milk or unadulterated milk, 
 when used singly or together, mean sweet milk not adulterated, and 
 the terms pure cream or unadulterated cream, when used singly 
 or together, mean cream taken from pure and unadulterated milk. 
 
 Seo. 21. Care and feed of cows. — No person shall keep cows, 
 for the production of milk for market or for sale or exchange, 
 or for manufacturing the milk or cream from th^ same into any 
 article of food, in a crowded or unhealthy condition, or feed any 
 such cows on distillery waste or on any substance in a state of 
 putrefaction or fermentation, or upon any food that is unhealthy, 
 or that produces impure, unhealthy, diseased or unwholsome milk. 
 But this section shall not be construed to prohibit the feeding of 
 ensilage. 
 
 Sec. 22. Prohibition of the sale of adulterated milk. — No person 
 shall sell or exchange, or offer or expose for sale or exchange, 
 any unclean, impure, unhealthy, adulterated or unwholesome milk 
 or any cream from the same, or sell or exchange, or offer or expose 
 for sale or exchange, any article of food made from such milk, or 
 of or from cream from the same, or manufacture from any such 
 milk or cream from the same, any article of food. 
 
 Sec. 23. Regulations in regard to butter and cheese factories. — ■ 
 No person shall sell, supply or bring to be manufactured to any 
 butter or cheese factory any milk diluted with water, or any un- 
 clean, impure, unhealthy, adulterated or unwholesome milk, or milk 
 from which any of the cream has been taken, except pure skim 
 milk to skim-cheese factories. No person shall sell, supply or 
 bring to be manufactured to any butter or cheese factory any milk 
 from which there has been kept back any part of the milk com- 
 monly known as strippings, or any milk that is sour, except pure 
 skim milk to skim-cheese factories. The owner or proprietor, or the 
 persons having charge of any butter or cheese factory, not buying 
 all the milk used by him, shall not use for his own benefit, or 
 allow any of his employes or any other person to use for his own 
 benefit, any milk, cream, butter or cheese or any other product 
 thereof, brought to such factory, without the consent of the own- 
 ers of such milk or the products thereof. Every butter or cheese 
 
284 Milk and Its Products. 
 
 manufacturer not buying all the milk he uses, shall keep a cor- 
 rect account of all the milk daily received, of the number of 
 packages of butter and cheese made each day, and the number of 
 packages and aggregate weight of cheese and butter disposed of 
 each day ; which account shall be open to inspection to any per- 
 son who delivers milk to such factory. 
 
 Sec. 24. Cans to be branded with the name of county. — No 
 person shall sell or offer or expose for sale or exchange any milk, 
 except in the county where produced, unless each can, vessel or 
 package containing such milk shall be distinctly and durably branded 
 with letters not less than one inch in length and of a suitable 
 width to correspond with such length, and with suitable spaces be- 
 tween the letters, on the outside, above the center, on every can, 
 vessel or package containing such milk, the iname of the county 
 from which the same is produced ; and the same letters shall be 
 branded or painted in a conspicuous place on the carriage or 
 vehicle in which the milk is drawn to be sold ; and such milk 
 shall not be sold by the producer outside of the county in which 
 it is produced, except in or out of a can, vessel, package or car- 
 riage or vehicle so marked. The foregoing prohibitions and provi- 
 sions of this section shall not apply when milk is sold or delivered 
 in glass bottles. No milk shall be sold or delivered in glass bot- 
 tles, except in the county where produced, unless such bottles 
 shall have legibly blown, stamped, engraved, etched, impressed or 
 moulded in the glass, or otherwise produced upon such bottles, the 
 name of the vendor, or the same is on a label or cover afBxed 
 thereto, or there is some mark or device on or af&xed to such 
 bottles by which the vendor may be ascertained. 
 
 Seo. 25. Regulations in regard to condensed milk. — No condensed 
 milk shall be made or offered or exposed for sale or exchange un- 
 less manufactured from pure, clean, healthy, fresh, unadulterated 
 and wholesome milk from which the cream has not been removed 
 either wholly or in part, or unless the proportion of milk solids 
 shall be in quantity the equivalent of 12 per centum of milk 
 solids in crude milk, and of which solids 25 per centum shall be 
 fats. No person shall manufacture, sell or offer for sale or ex- 
 change in hermetically sealed cans, any condensed milk unless put 
 up in packages upon which shall be distinctly labeled or stamped 
 the name of the person or corporation by whom made, and the 
 brand by which or under which it is made. When condensed milk 
 shall be sold from cans or packages not hermetically sealed, the 
 
Dairy Laws. 285 
 
 vendor shall brand or label such cans or packages with the name 
 of the manufacturer of the milk contained therein. 
 
 Sec. 26. Manufacture and sale of imitation butter prohibited. — 
 No person, by himself, his agents or employes, shall produce or 
 manufacture out of or from any animal fats or animal or vegetable 
 oils not produced from unadulterated milk, or cream from the same, 
 any article or product in imitation or semblance of natural butter 
 produced from pure, unadulterated milk or cream of the same ; nor 
 shall any person solicit or take orders for the same, or offer the 
 same for sale, or mix, compound with or add to milk, cream or 
 butter any acids or other deleterious substance, or any animal fats 
 or animal or vegetable oils not produced from milk or cream, so 
 as to produce any article or substance, or any human food in imi- 
 tation or in semblance of natural butter, nor sell, keep for sale or 
 offer for sale any article, substance or compound made, manufac- 
 tured or produced in violation of the provisions of this section, 
 whether such article, substance or compound shall be made or pro- 
 duced in this state or elsewhere. 
 
 Sec. 27. Manufacture of* mixing of animal fats with milk, 
 cream or butter prohibited. — No person shall manufacture, mix, or 
 compound with or add to natural milk, cream or butter any ani- 
 mal fats or animal or vegetable oils, nor make or manufacture any 
 oleaginous substance not produced from milk or cream, with intent 
 to sell the same as butter or cheese made from unadulterated milk 
 or cream or have the same in his possession with such intent ; nor 
 shall any person solicit or take orders for the same or offer the 
 same for sale, nor shall any such article or substance or compound, 
 so made or produced, be sold as and for butter or cheese, the pro- 
 duct of the dairy. No person shall coat, powder or color with 
 annatto or any coloring matter whatever, butterine or oleomargarine 
 or any compound of the same, or any product or manufacture 
 made in whole or in part from animal fats or animal or vege- 
 table oils not produced from unadulterated milk or cream by means 
 of which such product, manufacture or compound shall resemble 
 butter or cheese, the product of the dairy ; nor shall he have the 
 same In his possession with intent to sell the same, nor shall he 
 sell or offer to sell the same. 
 
 Seo. 28. Prohibited articles not to be furnished. — Nor keeper or 
 proprietor of any bakery, hotel, boarding-house, restaurant, saloon- 
 
 ^Bo in tne oneinai. 
 
286 Milh and Its Products. 
 
 lunch-counter or place of public entertainment, or any person hav- 
 ing charge thereof or employed thereat, or any person furnishing 
 board for any others than members of his own family, or for any 
 employes where such board is furnished for a compensation or as 
 part of the compensation of any such employe, shall keep, use or 
 serve therein, either as food for his guests, boarders, patrons, cus- 
 tomers or employes, or for. cooking purposes, any article or sub- 
 stance made in violation of the provisions of this article. 
 
 Sec. 29. Use of coloring matter prohibited. — No person manu- 
 facturing with intent to sell any substance or article in Imitation 
 or semblance of butter or cheese not made exclusively from un- 
 adulterated milk or cream, or both, with salt or rennet, or both, and 
 with or without coloring matter or sage, but into which any animal, 
 intestinal or offal fats, or any oils or fats or oleaginous substance 
 of any kind not produced from from* pure, unadulterated milk or 
 cream, or Into which melted butter, or butter in any condition or 
 state or any modification of the same, or lard or tallow shall be 
 introduced, shall add thereto or combine therewith any annatto or 
 compounds of the same, or any other substance or substances what- 
 ever, for the purpose or with the effect of imparting thereto a, 
 color resembling yellow, or any shade of yellow butter or cheese, 
 nor introduce any such coloring matter or other substance into any 
 of the articles of which the same is composed. 
 
 Sec. 30. Manufacture and sale of imitation cheese prohibited. — No 
 person shall manufacture, deal in, sell, offer or expose for sale or 
 exchange any article or substance, in the semblance of or in imi- 
 tation of cheese made exclusively of unadulterated milk or cream, 
 or both, into which any animal, intestinal or offal fats or oils, or 
 melted butter or butter in any condition or state or modification of 
 the same, or oleaginous substances of any kind not produced from 
 unadulterated milk or cream, shall be introduced. 
 
 Seo. 31. When prohibitions do not apply to skim milk or skim, 
 cheese. — Except in the counties of New York and Kings, the pro- 
 hibitions contained in this article against the sale of adulterated 
 milk shall not apply to skim milk which is clean, pure, healthy, 
 wholesome and unadulterated, except by skimming, sold for use in 
 the county in which it is produced or an adjoining county, if it 
 is sold for and as skimmed milk. The prohibitions in this article 
 against the sale of cheese made from unadulterated milk or cream 
 
 *So in the original. 
 
Dairy Laws. 287 
 
 shall not apply to pure skim cheese made from milk which is 
 clean, pure, healthy, wholesome and unadulterated, except by skim- 
 ming. 
 
 Sec. 32. Packages to be branded with name of maker. — No man- 
 ufacturer of receptacles for the package of butter shall sell or dis- 
 pose of any such receptacle without branding his name and the 
 true weight of the receptacle upon the same with legible letters or 
 figures not less than one-quarter of an inch in length. No person 
 shall sell, or offer for sale, any package containing butter or lard 
 packed by him unless the true weight thereof, with the initial let- 
 ters of the name of the person packing such butter or lard, be 
 marked or stamped in «. legible manner on the side or head of such 
 package. 
 
 Sec. 33. Manufacturer's brand of cheese. — Every manufacturer 
 of full milk cheese may put a brand upon each cheese indicating 
 "full milk cheese," and the date of the month and year when 
 made, and no person shall use such a brand upon any cheese made 
 from milk from which any of the cream has been taken. The 
 Commissioner of Agriculture shall procure and issue to the cheese 
 manufacturers of the state, on proper application therefor, and under 
 such regulations as to the custody and use thereof as he may pre- 
 scribe, a, uniform stencil brand, bearing a, suitable device or motto, 
 and the words, "New York state full cream cheese." Every such 
 brand shall be used upon the outside of the cheese and upon the 
 package containing the same, and shall bear a different number for 
 each separate factory. The Commissioner shall keep a book, in 
 which shall be registered the name, location and number of each 
 manufactory using the brand, and the name or names of the per- 
 sons at each manufactory authorized to use the same. No such 
 brand shall be used upon any other than full-cream cheese or pack- 
 ages containing the same. 
 
 Sec. 34. Use of false brand prohibited. — No person shall offer, 
 sell, or expose for sale, in any package, butter or cheese which is 
 falsely branded or labeled. 
 
 Sec. 35. County trade-marks. — At a regular or. special meeting 
 of a county dairyman's association in any county of the state there 
 may be adopted a county trade-mark, by a majority of the mem- 
 bers present and voting, to be used as a trade-mark by am* 
 
 *So in the oriffinal. 
 
288 Milk and Its Products. 
 
 person manufacturing pure unadulterated butter or full-cream cheese 
 in such county. The secretary of the association shall forthwith 
 send to the Commissioner of Agriculture a copy of such trade-mark, 
 which copy he shall place on file in his office, noting thereupon the 
 day and hour he received the same. But one county trade-mark 
 for butter and for cheese shall be placed on file for the same 
 county. No association shall adopt any trade-mark of any county 
 already on file, or use that of any other county in the formation 
 of a trade-mark. 
 
 Sec. 36. Object and intent of this article. — This article and each 
 section thereof are declared to be enacted to prevent deception in 
 the sale of dairy products, and to preserve the public health, which 
 is endangered by the manufacture, sale and use of the articles or 
 substances herein regulated or prohibited. 
 
 Sec. 37. Penalties. — Every person violating any of the provisions 
 of this article shall forfeit to the people of the state of New York 
 the sum of one hundred dollars for every such violation. When 
 such violation consists of the manufacture or production of any 
 prohibited article, each day during which or any part of which such 
 manufacture or production is carried on or continued shall be 
 deemed a separate violation of the provisions of this article. When 
 the violation consists of the sale, or the offering or exposing for 
 sale or exchange of any prohibited article or substance, the sale of 
 each one of several packages shall constitute a separate violation, 
 and each day on which any such article or substance is offered or 
 exposed for sale or exchange shall constitute a separate violation of 
 this article. When the use of any such article or substance is 
 prohibited, each day during which or any part of which said article 
 or substance is so used or furnished for use shall constitute a 
 separate violation, and the furnishing of the same for use to each 
 person to whom the same may be furnished shall constitute a 
 separate violation. 
 
References. 289 
 
 D. REFERENCES TO AGRICULTURAL EXPERIMENT 
 STATION REPORTS AND BULLETINS. 
 
 The following references will aid the student who desires to make 
 a more thorough study of the subjects discussed. They are taken 
 wholly from the literature of American agricultural investigations, 
 and include only some of the more important articles. The Experi- 
 ment Station Record and the Handbook of Experiment Station Work, 
 both issued by the U. S. Department of Agriculture, contain many 
 condensed results of dairy investigation. 
 
 Chapter I. 
 
 Studies in Milk Secretion. Indiana Bull. No. 24, pp. 13-16. 
 How is Milk Formed? Nevada Bull. No. 16, pp. 4-5. 
 Elaboration of Milk. Ontario Rept. for 1893, pp. 165-166. 
 Dividing Milkings. Indiana Bull. No. 24, pp. 10-13. 
 Milking Two and Three Times per Day. Vermont Rept. for 
 1890, pp. 90-96. 
 
 Chapter II. 
 
 The Composition of Milk. Ontario Bull. No. XXXIX. 
 
 The Mineral Ingredients of Milk. Maine Rept. for 1890, part 
 II., pp. 52-57. 
 
 The Constitution of Milk, and Some of the Conditions which 
 Affect the Separation of Cream. Wisconsin Bull. No. 18. 
 
 Conditions Affecting the Consistency of Milk. Wisconsin Rept. 
 for 1896, pp. 73-80. 
 
 Chemistry of Dairy Products. Ontario Rept. for 1890, pp. 237-241. 
 
 Milk Analysis. Connecticut Rept. for 1886, pp. 119-130. 
 
 Investigations Relating to the Composition of Milk. Wisconsin 
 Rept. for 1890, pp. 114-119. 
 
 Fibrin in Milk. Wisconsin Rept. for 1893, pp. 143-145. 
 
 Relation of Pat and Casein in Milk. Vermont Rept. for 1890, pp. 
 97-100. 
 
 The Composition, Creaming and Churning of Colostrum. Vermont 
 Rept. for 1891, pp. 104-108. 
 
 The Pat Globules of Milk. New York Rept. for. 1885, pp. 266- 
 275; Wisconsin Rept. for 1894, pp. 223-239; Ontario Rept. for 1885, 
 pp. 127-130. 
 
290 Millc and Its Products. 
 
 The Effects of Feed Upon the Quality of Milk. Iowa Bull. No. 14, 
 pp. 123-142 ; New Hampshire Bept. for 1893, pp. 138-155, and Bull. 
 No. 9 ; Bull. No. 16 ; Bull. No. 18 ; Bull. No. 20. 
 
 Tests of Several Breeds of Dairy Cows. A Study of Dairy Pro- 
 ducts. Maine Kept, for 1889, pp. 106-134. The test is continued in 
 Rept. for 1890, Part II., pp. 17^2. 
 
 Corn Silage for Milch Cows. New York (State) Bull. No. 97, 
 New Series. 
 
 Investigations of the Several Breeds of Dairy Cattle. New York 
 (State) Reports for 1891, 1892, 1893, 1894. 
 
 On the Effects of Feeding Fat to Cows. New York (Cornell) 
 Bull. No. 92. 
 
 Variations in Milk. Illinois Bull. No. 17, pp. 9-16, and Bull. No. 24. 
 
 The Influence of Advancing Lactation upon the Production of But- 
 ter and Cheese. New York (State) Rept. for 1891, pp. 369-389. 
 
 Effects of Drouth upon Milk Production. New York (State) Bull. 
 No. 105. New Series. 
 
 Variations in Milk. Vermont Rept. for 1891, pp. 61-74. 
 
 Variations in Quantity and Quality of Milk. Vermont Rept. for 
 1892, pp. 90-119, and Bull. No. 38. 
 
 The Composition of Milk as Affected by Methods of Milking. 
 Wisconsin Rept. for 1889, pp. 44, 51, 61. 
 
 Chapter III. 
 
 Milk Tests. (Short, Lactoscope.) Illinois Bull. No. 9, pp. 293-302. 
 
 Investigation of Milk Tests. (Short, Parsons, Failyer and Willard, 
 Cochran, Patrick,) Illinois Bull. No. 10. 
 
 Milk Tests : Methods of Testing Milk. (Patrick; Babcock, Beim- 
 ling, Gravimetric.) Illinois Bull. No. 14, pp. 462-467. 
 
 Methods of Testing Milk. (Short, Patrick, Cochran, Babcock, 
 Beimling.) West Virginia Bull. No. 13, pp. 41-63. 
 
 Testing Milk. (Short, Patrick, Cochran, Babcock, Soxhlet, Beim- 
 ling. ) West Virginia Report for 1890, pp. 68-88. 
 
 A New Volumetric Method for the Estimation of Fat in Milk, 
 Skimmed Milk, Buttermilk and Cream. (Parsons.) New Hampshire 
 Report for 1888, pp. 66-83. 
 
 Babcock and Beimling Tests. Ontario Report for 1891, pp. 183- 
 184. 
 
 Simple Methods of Determining Milk Fat. (Short, Cochran, Gravi- 
 metric.) Pennsylvania Bull. No. 12. 
 
References. 291 
 
 Comparative Test of Machines and Methods for the Determination 
 of Fat in Milk. (Short, Beimling, Patrick, Babcock, Gravimetric.) 
 Mis.sissippi Bull. No. 15, pp. 5-16. 
 
 A Description of Cochran's Method for the Determination of Fat 
 in Milk, for the Use of Dairymen. New York (Cornell) Bull. No. 
 XVII. 
 
 Iowa Station Milk Test. (Patrick). Iowa Bull. No. 8, pp. 295- 
 316; No. 9, p. 355; No. 11, pp. 484-487. 
 
 A New Method for Determining the Amount of Butter Pat in 
 Milk. Mississippi Bull. No. 21, pp. 17-19. 
 
 A New Milk Test. (Beimling). Vermont Bull. No. 21. 
 
 The Lactanalyt, A New Milk Tester. Vermont Report for 1894, 
 pp. 161-162. 
 
 A New Method of Milk Analysis (Short) for the Use of Dairy- 
 men, and a. Comparison of Its Results with those Obtained by the 
 Churn. Kansas Report for 1888, pp. 149-164. 
 
 A Method for the Determination of Fat in Milk and Cream. 
 (Parsons.) New York (State) Bull. No. 19. New Series. 
 
 Feser's Lactoscope and Fjord's Centrifugal Controller, described 
 in Ontario Report for 1885, pp. 207-208. 
 
 Testing Milk at Creameries. (Short.) Vermont Bull. No. 16. 
 
 The Sehoch and Bolender Test Churn. Wisconsin Report for 
 1884, pp. 23-25. 
 
 Description of the Test Churn. Ontario Report for 1885, p. 201. 
 
 The Oil Test for Cream. Wisconsin Bull. No. 12. 
 
 A New Method for Determining Fat in Milk. (Short.) Wiscon- 
 sin Bull. No. 16 and Report for 1888, pp. 124-136. 
 
 The Babcock Milk Test was first described in Wisconsin Bull. 
 No. 24 and Report for 1890, pp. 98-113. Improvements and modifi- 
 cations are discussed in Bull. No. 31, pp. 3-16 ; Bull No. 36, pp. 
 3-20 ; Bull No. 52, Report for 1892, pp. 219-244 ; Report for 1893, 
 pp. 116-121. Compared with the Gravimetric Method in Report for 
 1890, pp. 138-143. 
 
 Elsewhere, the method has been described in Pennsylvania Bull. 
 No. 33 ; Washington Bull. No. 18 ; New York (Cornell) Bull. No. 29, 
 pp. 77-80 ; Colorado Bull. No. 20, pp. 3-10 ; North Carolina Bull. No. 
 113, pp. 101-111; West Virginia Bull. No. 13, pp. 52-57; Ontario Bull. 
 No. LXI. ; Bull. No. XCIII., pp. 5-6 ; Connecticut Bull. No. 106, pp. 
 2-9 ; Bull No. 108, pp. 5-11 ; Bull No. 117, Report for 1894, pp. 209- 
 244 ; Maine Bull. No. 3, Second Series ; Bull No. 4, Report for 1891, 
 Part II., pp. 71-80; Michigan Bull. No. 127; Illinois Bull. No. 27; 
 North Dakota Bull. No. 22 ; Pennsylvania Report for 1895, Part II., 
 
292 
 
 Milk and Its Products. 
 
 pp. 90-100 ; Nevada Bull. No. 16, pp. 41-51 ; Mississippi Bull. No. 15, 
 pp. 7-14. 
 
 Milli Sampling. Delaware Bull. No. XXXI. 
 
 Composite Milk Samples Tested for Butter Fat. Illinois Bull. 
 No. 16, pp. 504-515. Continued in Bull. No. 18, pp. 27-28. 
 
 The Composite Sample. Preservatives for Keeping Milk — Samples 
 for Testing. Iowa Bull. No. 11, pp. 482-484. 
 
 Composite Samples at the Creamery — Chromate Preservatives. 
 Iowa Bull. No. 22, pp. 836-844. 
 
 Detection of Adulterations in Milk. Wisconsin Bull. No. 31, pp. 
 17-27; Bull. No. 36, pp. 21-31, and Report for 1892, pp. 245-257. 
 Ontario Bull. No. XCIII., pp. 3-5; Vermont Newspaper Bull. No. 4. 
 
 Lactometer and Milk Test for Examining Milk. Minnesota Bull 
 No. 27, pp. 55-56. 
 
 The Relation between Specific Gravity and Solids of Milk. Wis- 
 consin Report for 1895, pp. 120-126. 
 
 The Estimation of the Total Solids in Milk from the Per Cent 
 of Fat, and the Specific Gravity of the Milk. Wisconsin Report for 
 1891, pp. 292-307, and Report for 1893, p. 142. 
 
 The Lactometer and Fat Test for Cheese and Condensed Milk 
 Factories Maine Bull. No. 4, New Series, pp. 6-10. 
 
 Chapter IV. 
 
 Dairy Bacteriology. U. S. Dept. Agr. Office of Expt. Stations. 
 Bull. No. 25. 
 
 The Fermentations of Milk. U. S. Dept. Agr. Expt. Stations. 
 Bull. No. 9. 
 
 Souring of Milk. U. S. Dept. Agr. Farmers' Bull. No. 29. 
 
 Milk Fermentations and Their Relations to Dairying. U. S. Dept. 
 Agr. Farmers' Bull. No. 9. 
 
 The Isolation of Rennet from Bacteria Cultures. Connecticut 
 (Storrs) Report for 1892, pp. 106-126. 
 
 The Sources of Bacterial Infection, and the Relation of the Same 
 to the Keeping Quality of Milk. Wisconsin Report for 1894, pp. 
 150-165. 
 
 Cleanliness in Handling Milk ; Bacteriological Considerations. 
 North Dakota Bull. No. 21. 
 
 A Mioroccus of Bitter Milk. Connecticut (Storrs) Report for 
 1891, pp. 158-162. 
 
 Pasteurization of Milk and Cream for Direct Consumption. Wis- 
 consin Bull. No. 44. 
 
Befennces. 293 
 
 Notes on Pasteurization of Milk and Cream. Wisconsin Report 
 for 1895, pp. 158-173. 
 
 On the Bestoration of the Consistency of Pasteurized Milk aud 
 Cream. Wisconsin Report for 1896, pp. 81-94, and Bull. No. 54. 
 
 A Preliminary Bulletin, on Pasteurization of Milk. Michigan Bull. 
 No. 134. 
 
 Preservation of Cream for Market. Maine Bull. No. 23, New 
 Series. 
 
 Chapter V. 
 
 Aeration and ASrators. New York (Cornell) Bull. No. 39, pp. 
 90-94. 
 
 Aeration of Milk. Vermont Report for 1892, pp. 123-128. 
 
 Concerning the Aeration of Milk. Indiana Bull. No. 44, pp. 37-39. 
 
 Town and City Milk Supply. U. S. Dept. Agr. Farmers' Bull. 
 No. 42, pp. 23-28. 
 
 Variations in Pat of Milk Served to Customers in Dipping from 
 Cans. New York (Cornell) Bull. No. XX., pp. 08-71. 
 
 Variations in the Fat of Milk. Ontario Bull. No. LXVI. 
 
 Chapter VI. 
 
 Cream Raising by Dilution. New York ( Cornell ) Bull. No. 20, 
 pp. 61-67 ; Bull. No. 29, pp. 65-71 ; Bull. No. 39, pp. 77-85 ; Illinois 
 Bull. No. 12, pp. 376-377 ; Bull. No. 18, pp. 30-32 ; Vermont Rept. for 
 1890, pp. 100-107. 
 
 Other Methods of Setting Milk. Minnesota Bull. No. 19, pp. 11- 
 19; Iowa Bull. No. 25, pp. 39-40; Indiana Bull. No. 44, pp. 23-37; Wis- 
 consin Rept. for 1884, pp. 17-22 ; Rept. for 1893, pp. 147-150 ; Bull. 
 No. 7, pp. 9-13 ; Bull. No. 29 ; Canada, Central Experimental Farm 
 Rept. for 1891, pp. 89-104 ; Rept. for 1892, pp. 71-74 ; Ontario Rept. 
 for 1894, pp. 142-144 ; Vermont Rept. for 1891, pp. 100-101 ; Maine 
 Bull. No. 5, Second Series ; Utah Bull. No. 42. 
 
 The Viscosity of Milk. New York (State) Rept. for 1886, pp. 323-330. 
 
 The Constitution of Milk, and Some of the Conditions Which Affect 
 the Separation of Cream. Wisconsin Bull. No. 18. 
 
 The Centrifugal Separation of Casein and Insoluble Phosphates from 
 Milk. Wisconsin Rept. for 1895, pp. 93-99. 
 
 Tests of Cream Separators. Delaware Bull. No. 17, and Rept. for 
 1892, pp. 110-122 ; Iowa Bull. No. 25, pp. 32-38 ; New Hampshire Rept. 
 for 1893, pp. 36-45 and Bull. No. 7; New York (Cornell) Bull. No. 66 
 and 105; North Carolina Bull. No. 114; Pennsylvania Rept. for 1892 
 
294 Milk and Its Products. 
 
 part II., pp. 51-79, and Bull. No. 20; Bull. No. 27, Rept. for 1894, 
 pp. 13-35; South Dakota Bull. No. 39; Vermont Bull. No. 27, and 
 Kept, for 1892, pp. 136-143; Eept. for 1893, pp. 92-100; Kept, for 
 1894, pp. 151-160; Wisconsin Rept. for 1895, pp. 151-157, and Bull. 
 No. 46 
 
 Chapters VII., VIII., IX. 
 
 Experiments with Boyd's Vat and Starter. Ontario Rept. for 1891, 
 pp. 178-179. 
 
 Bacteria in the Dairy. Connecticut (Storrs) Rept. for 1895, pp. 
 14-41. 
 
 The Use of Bacterial Culture Starters in Butter Making, With 
 Especial Reference to the Conn Culture { B. 41). Wisconsin Rept. for 
 1895, pp. 174-231; published, in part, in Bull. No. 48. 
 
 An Acid Test of Cream. Illinois Bull. No. 32, and Bull. No. 33, 
 pp. 399-400. 
 
 The Alkaline Tablet Test of Acidity in Milk or Cream. Wisconsin 
 Bull. No. 52, pp. 8-16. 
 
 Sweet Versus Sour Cream Butter. Iowa Bull. No. 8, pp. 317-320: 
 Bull. No. 11, pp. 481-482 ; Bull. No. 18, pp. 478-487 ; Bull. No. 21, pp. 
 788-791; Illinois Bull. No. 9, pp. 301-302; Texas Bull. No. 11, pp. 
 15-10 ; Ontario Rept. for 1891, pp. 179-181 ; West Virginia Rept. for 
 1890, pp. 48-66. 
 
 Creamery Studies of Methods and Machinery. A comparison 
 of the Sour Cream, Sweet Cream and Butter Extractor Processes. 
 Delaware Rept. for 1890, pp. 17-23, and pp. 129-149; also Bull. 
 No. IX. 
 
 Our Experience with Extractor Butter. Ontario Rept. for 1893, 
 pp. 170-171. 
 
 A Study in Churning. Iowa Bull. No. 22, pp. 819-832. 
 
 Churning Experiments. Vermont Rept. for 1893, pp. 100-106. 
 
 Butter Tests. New York (State) Rept. for. 1884, pp. 334-347, and 
 Rept. for 1885, pp. 275-292. 
 
 The Effect of Succulent Pood Upon the Churnability of the Fat in 
 Milk. Vermont Rept. for 1890, pp. 70-74. 
 
 Butter Making. Ontario Rept. for 1889, pp. 161-163; Bull. No. 
 XLVIII. 
 
 Canada Central Experimental Farm Dairy. Bull. No. 3. 
 
 Washing and Salting Butter. Minnesota Bull. No. 7, pp. 34-42. 
 
References. 295 
 
 Chaptbrs X., XI. 
 
 For references to aeration, see Chapter V. 
 
 Points of Attention for the Patrons of Cheese Factories and Cream- 
 eries. Ontario Bull. No. II. 
 
 Milk for Cheese Making. Ontario Bull. No. XLI.; Bull. No. 
 XXVIII.; Bull. XCIV.; Canada Central Experimental Farm Dairy. 
 Bull. No. 1. 
 
 Pure Lactic Culture of Bacteria in Cheese Making. Wisconsin Rept. 
 for 1896, pp. 112-126. 
 
 Rennet Extracts of Commerce. Iowa Bull. No. 22, pp. 845-851. 
 
 Losses in Cheese Making. Vermont Rept. for 1891, pp. 95-100. 
 
 The Effect of Salt Upon Cheese. Wisconsin Rept. for 1894, pp. 
 220-222. 
 
 The Effect of Aeration on the Flavor of Tainted Curds in Cheese 
 Making. The Influence of Acid on the Texture of Cheese. The Hot 
 Iron Test. Experiments in Ripening the Milk before Setting. Wis- 
 consin Rept. for 1895, pp. 127-138. 
 
 Experiments in the Manufacture of Cheese. New York ( State ) 
 Eepts. for 1891, p. 216; 1892, p. 295; 1893, p. 239; 1894, p. 263. 
 
 Hints to Cheese Makers. Iowa Bull. No. 19, pp. 627-631. 
 
 Investigations in Cheese Making. Iowa. Bull. No. 21, pp. 735-767. 
 
 Experiments in Cheese Making. Minnesota Bull. No. 19, pp. 
 20-25. 
 
 Experiments in the Manufacture of Cheese. Wisconsin Rept. for 
 1894, pp. 131-149. 
 
 The Relation Between Milk Solids and the Yield of Cheese. Wis- 
 consin Rept. for 1895, pp. 100-119. 
 
 Notes for Cheese Makers for May. Ontario Bull. No. XL. ; for July, 
 Bull. No. XLIII.; for August, Bull. No. XLIV.; for October, Bull. 
 No. XLVII. Rept. for 1889, pp. 163-179. 
 
 Notes for Cheese Makers for May. Canada Central Experimental 
 Farm, Dairy Bull. No. 2; Special Dairy Bulletins for July, August, 
 October and June. 
 
 Articles on Spring, Summer and Pall Cheese in Ontario Rept. for 
 1893, pp. 167-170. 
 
 Gas Producing Bacteria, and the Relation of the Same to Cheese. 
 Wisconsin Rept. for 1895. 
 
 The Rise and Pall of Bacteria in Cheddar Cheese. Wisconsin Rept. 
 for 1896, pp. 95-111. 
 
 An Aromatic Bacillus of Cheese. Iowa Bull. No. 21, pp. 792-796. 
 
 Changes During Cheese Ripening. Iowa Bull. No. 24, pp. 969-984. 
 
296 Milh and Its Products. 
 
 Moisture Supply in Cheese Curing Rooms. Wisconsin Rept. for 
 1896, pp. 156-163. 
 
 Experiments Upon the Curing of Cheese. Cornell University Agr. 
 Exp. Sta. Rept. for 1880, pp. 9-27. 
 
 Chapter XII. 
 
 The Manufacture of Sweet Curd Cheese (Edam and Gouda). Min- 
 nesota Rept. for 1894, pp. 104-128, and Bull. No. 35. 
 
 Experiment Relating to the Manufacture of Edam and Gouda Cheese. 
 New York (State) Rept. for 1893, pp. 244-269, and Bull. No. 56. 
 
 Albumin Cheese. Wisconsin Rept. for 1895, pp. 134-136. 
 
 Chapter XIII. 
 
 The Manufacture of Milk Sugar (Report of Chemist). Delaware 
 Report for 1891, pp. 104-108. 
 
 The Hog as an Adjunct to the Dairy. Ontario Report for 1889, 
 pp. 184-189. 
 
 Whey Butter. New York (Cornell) Bull. No. 85. 
 
 Sweet Skim Milk ; Its Value as Food for Pigs and Calves. 
 Wisconsin Bull. No. 1. 
 
 The Feeding Value of Whey. Wisconsin Bull. No. 27, Report 
 for 1891, pp. 38-48. 
 
 Feeding Waste Products of the Dairy. Wisconsin Report for 
 1886, pp. 21-25. 
 
 The Value of Creamery Separator Skim Milk for Swine Feeding. 
 Wisconsin Report for 1895, pp. 7-23. 
 
 Chapter XIV. 
 
 Building Creameries and Organization of Cooperative Creamery 
 Companies. South Dakota Bull. No. 46. 
 
 Creameries for Texas ; Plans and Specifications in Full for Cream- 
 ery Outfit. Texas Bull. No. 5. 
 
 Cooperative Creameries. Minnesota Report for 1894, pp. 93-103, 
 and Bull. No. 35. 
 
 The Establishment of Cheese Factories and Creameries. Special 
 Bull, of the Central Canada Experimental Farm, Ottawa. 
 
 By-Laws, Rules and Regulations for Cheese Factories. Canada 
 Central Experimental Farm Dairy Bull. No. 9. 
 
References. 297 
 
 By-Laws, Rules and Regulations for Creameries on the Cream- 
 Gathering Plan. Central Experimental Farm, Dairy Bull. No. 10. 
 
 Chapter XV. 
 
 Statistics of the Dairy. U S. Dept. Agr., Bureau of Animal In- 
 dustry. Bull. No. 11. 
 
 Returns from the Ninth, Tenth and Eleventh Censuses, Relating 
 to the Production of Milk, Butter and Cheese on the Farm. U. S. 
 Dept. Agr., Report of the Statistician, No. 113, pp. 115-118. 
 
 General. 
 
 Facts About Milk. U. S. Dept. Agr., Farmers' Bull. No. 42. 
 
 The Dairy Industry in Denmark. U. S. Dept. Agr., Bureau of 
 Animal Industry, Bull. No. 5. 
 
 The Creamery Industry. Nevada Bull. No. 16. 
 
 Dairying. South Carolina Bull. No. 19. 
 
 Dairying in California. U. S. Dept. Agr., Bureau of Animal In- 
 dustry, Bull. No. 14. 
 
 Dairy Farming in Washington. Washington Bull. No. 2, pp. 23-27. 
 
 The Dairy Industry in Nebraska, South Dakota and North Dakota. 
 U. S. Dept. Agr., Bureau of Animal Industry, Bull. No. 16. 
 
INDEX. 
 
 PAGE 
 
 Ahnorma) fermentations 71 
 
 Accumulator 123 
 
 Accuracy of Babcoek test glass- 
 ware 57 
 
 Acid, boracic 79 
 
 — butyric 23 
 
 — capric 23 
 
 — caproic 23 
 
 — eaprylie 23 
 
 — citric 26 
 
 — dioxystearic 23 
 
 — hydrochloric, for ripening cream . 129 
 
 — lactic 25, 74, 130 
 
 determination of 135, 2C1 
 
 — lauric 23 
 
 — myristic 22 
 
 — oleic 22 
 
 — palmitic 22 
 
 — salicylic 79 
 
 — stearic 22 
 
 — sulphuric 62 
 
 — test, Manns' 134 
 
 Acini 3 
 
 Act. Filled cheese 256, 276 
 
 — oleomargarine 255, 269 
 
 Adams' method 36 
 
 Adjustable separator 123 
 
 Aeration of milk 86, 172 
 
 Aerators, milk 87 
 
 Aerometer, Soxhlet's 45 
 
 Agricultural Experiment Station 
 
 Bulletins 289 
 
 — mentioned 46 
 
 Air drainage 237 
 
 PAGE 
 
 Albumin 23 
 
 Albuminoids 23 
 
 Alcoholic fermentation 71 
 
 Alexandra Jumbo separator 124 
 
 Aliquot milk sampler 60 
 
 Alkali, decinormal 135, 261 
 
 135 
 85 
 
 ~ use of in cleaning 
 
 Alkaline tablets, Farrington's 
 
 81, 135, 261 
 Alph.a discs or plates 119 
 
 — separator 124 
 
 Alveoli 3 
 
 American cheddar cheese 179 
 
 — home-trade cheese 200 
 
 — Neufchatel cheese 203 
 
 Amphoteric reaction 66 
 
 Analysis, gravimetric 35 
 
 Angus, J. J . , mentioned 233 
 
 Aniline butter color 161 
 
 Animal excrement, relation of 
 
 bacteria to 77 
 
 — odor 86 
 
 Annatto 161 
 
 Antiseptics 78 
 
 Apparatus, Fjord's control 45 
 
 — pasteurizing 81 
 
 Arnold, L. B., quoted 104 
 
 Arnold's separator 123 
 
 Asbestos method of determination 
 
 of fat 36 
 
 Ash of milk 25 
 
 Asses' milk 16 
 
 (299) 
 
300 
 
 Index 
 
 PAGE 
 
 Associated dairying 250 
 
 AyrsMre milk 33 
 
 B41 331 
 
 Babcock, Dr. S. M., mentioned . . 47, 49 
 quoted. .,17, 95, 104,166,254 
 
 — asbestos method 36 
 
 — formula for solids not fat 260 
 
 — test 49 
 
 calibration of glassware 265 
 
 details 52 
 
 Bacillus 67 
 
 — acidi lactici 73 
 
 — No, 41 131 
 
 — prodigiosus 72 
 
 — tubercle 80 
 
 Bacteria 67 
 
 — in milk 69 
 
 — relation of animal excrement to. 77 
 
 dust to 77 
 
 to hay and dried forage 77 
 
 Bad flavors in milk 91 
 
 Barber, quoted 132 
 
 B. and W. test bottle 54 
 
 Beimling, H. F., mentioned 50 
 
 — test 50 
 
 Bernstein, A., mentioned 234 
 
 Bichromate of potash 59 
 
 Bitter milk 71 
 
 Black specks in Babcock test 63 
 
 Blood, relation of to milk secretion. 11 
 
 "Bloodybread" 72 
 
 Board of Health lactometer 38, 259 
 
 Boracic acid 79 
 
 Borden, Gail, Jr., mentioned 253 
 
 Bottle, Babcock test 52 
 
 Bottling milk 90 
 
 " Breaking " of butter 146 
 
 Breed, influence of on composition 
 
 of milk 32 
 
 Brie cheese 225 
 
 Brine-salting butter' 157 
 
 Brown separator, medium 123 
 
 Bulletins and reports_of Agr. Exp. 
 
 Stations 289 
 
 Buildings, farm dairy 245 
 
 PAQK 
 
 Burette 136 
 
 Butter accumulator 123 
 
 — and cheese factories, combined.. 244 
 
 — "breaking" of 146 
 
 — color 161 
 
 — composition of 159 
 
 — estimation of fat in, by Babcock 
 
 test 56 
 
 — factories 236 
 
 — " factory " 257 
 
 — finish 162 
 
 — flavor 160 
 
 — granules, size of 151 
 
 — imitation creamery 257 
 
 Buttermilk 229 
 
 — characteristic appearance of 147 
 
 — separation of , from butter 150 
 
 Butter, mottled and streaked 156 
 
 — packages 158 
 
 — packing and marketing 157 
 
 — prints 159 
 
 — " process " 257 
 
 — quality of 159 
 
 — rancid 20 
 
 — renovated 257 
 
 — relation of lactic acid to keep- 
 
 ing quality 137. 
 
 wash-water to flavor 153 
 
 — to texture 152 
 
 — salting 154 
 
 — scale of perfection 163 
 
 — sweet cream 128, 137 
 
 — texture of 128, 160 
 
 — washing 150 
 
 — white specks in 138 
 
 — working 153 
 
 Butyric acid 20-23 
 
 — ^fermentations 71, 76 
 
 Butyrin 20 
 
 Butyrometer 51 
 
 Oalibration of Babcock test glass- 
 ware 57.265 
 
 Gamembert cheese 225 
 
 Canadian Club cheese 209 
 
 Capric acid 23 
 
 Caprilin 20 
 
Index 
 
 301 
 
 PAGE 
 
 Caprin 2C 
 
 Caproic acid 23 
 
 Caproin.... 20 
 
 Caprylic acid '. 23 
 
 Careno, mentioned 26 
 
 Casein 23 
 
 — dried 230 
 
 — coagulation of 164 
 
 — formation of 8 
 
 Caustic potash 60 
 
 — soda 60 
 
 Cement floors 230 
 
 Centigrade thermometer 259 
 
 Centrifugal force, relation of to 
 
 complete creaming 115 
 
 — separation Ill 
 
 theory of 113 
 
 — system 98 
 
 Cheddar cheese 179 
 
 Cheddar, English 210 
 
 Cheddaring 187 
 
 Cheese 163 
 
 — American home- trade 200 
 
 Neufchatel 203 
 
 — and butter factories combined . . 244 
 
 — Brie 225 
 
 — Camembert 225 
 
 — Canadian Club 209 
 
 — Cheddar 179 
 
 — Cheshire 216 
 
 — Club-house 209 
 
 — color of 198 
 
 — composition of 197 
 
 — cottage 232 
 
 — cream 200 
 
 — curing 193 
 
 rooms, construction of 244 
 
 — D'Isiginy 227 
 
 — double Gloucester 210 
 
 — Edam 220 
 
 — English 210 
 
 Cheddar 210 
 
 — estimation of fat in, by Babcock 
 
 test 56 
 
 — Derbyshire 218 
 
 — Duteh 232 
 
 PAGE 
 
 Cheese Emmenthaler 219 
 
 — factories , 236 
 
 arrangement of 243 
 
 — filled, law 276 
 
 — flavor of 197 
 
 — ''flinty break" 198 
 
 — food 233 
 
 — formation of rind 193 
 
 — Gloucester 210 
 
 — Gouda 22i 
 
 — Gorgonzola 219 
 
 — Gniyere 219 
 
 — hard 199 
 
 — imitation Swiss 209 
 
 — Lancashire 218 
 
 — law, filled 256 
 
 — Leicestershire 218 
 
 — Limburger 207 
 
 — making, cheddaring 187 
 
 cooking 185 
 
 — — cooling milk for 171 
 
 curing 193 
 
 cutting 183 
 
 heating 185 
 
 — — grinding 189 
 
 ■ loss of fat in 170 
 
 — — matting 187 
 
 — — over-ripe milk in 196 
 
 — — pressing 191 
 
 quality of milk for 164 
 
 ripening of milk for 172 
 
 setting 181 
 
 salting 190 
 
 undesirable fermentations in . 194 
 
 use of starters 175 
 
 — ' Meadow Sweet 209 
 
 — Neufchatel 203 
 
 — Parmesan 228 
 
 — Philadelphia cream 207 
 
 — picnic 203 
 
 — pineapple 203 
 
 — poisonous 73 
 
 — Pont L'EveQue 227 
 
 — pot 232 
 
 — Port du Salut 228 
 
 — prepared 209 
 
302 
 
 Index 
 
 PAGE 
 
 Cheese press , 192 
 
 — qualities of 137 
 
 — rind 198 
 
 — Roquefort 16, 231 
 
 — sage 202 
 
 — scale of perfection for 198 
 
 -— Schweitzer 219 
 
 — single Gloucester 210 
 
 — skimmed 200, 2oG 
 
 — soft 199 
 
 — solids coneerned in making 163 
 
 — Square cream 207 
 
 — Stilton 210 
 
 — stirred curd 200 
 
 — Swiss 219 
 
 — texture of 197 
 
 — truckle 203 
 
 — Wensleydale 219 
 
 — "wet." "sloppy," or "leaky" . . ..202 
 
 — whey 232 
 
 — Wiltshire 210 
 
 — Young America 203 
 
 Cheshire cheese 216 
 
 Chloride of potash 25 
 
 — of soda 25 
 
 Chromogenie fermentations 71 
 
 Churn, oil test 42 
 
 — tests 41 
 
 Churning 140 
 
 — amount of motion necessary 145 
 
 — difficult 147 
 
 — dilution of cream 148 
 
 — kind of agitation desirable 143 
 
 — relation of fat globules to 145 
 
 — — of ripeness of cream to.. .137, 141 
 
 — — of temperature to 141 
 
 of viscosity to 140 
 
 — rise of temperature in 149 
 
 Cistern, milk , 5 
 
 Citric acid 26 
 
 Cleaning tinware 84 
 
 — utensils 13 
 
 Cleanliness 83 
 
 Club-house cheese 200 
 
 Cloth strainers 85 
 
 Coagulation , 164 
 
 PAGE 
 
 Coccus 6" 
 
 Cochran, C. B. , mentioned 49 
 
 Cochran's method 49 
 
 Cold storage 258 
 
 Columbia separator 123 
 
 Color fermentations 71 
 
 — of butter 160 
 
 — of cheese 198 
 
 Colostrum 9, 18 
 
 — composition of 18 
 
 — corpuscles 18 
 
 — test for 18 
 
 Combined butter and cheese fac- 
 tories 244 
 
 Commercial lactic ferment 130 
 
 Comparison of lactometer scales 260 
 
 — of thermometer scales 259 
 
 Composite sampling 59 
 
 Composition of butter 159 
 
 — of cheese 197 
 
 — of cream 97 
 
 — of milk 17 
 
 Concussion in churning 143 
 
 Condensed milk 253 
 
 Conn culture 132 
 
 — H. W.. mentioned 129, 131 
 
 Connective tissue 3 
 
 Constituents of milk 16 
 
 Construction of creameries 240 
 
 Control apparatus. Fjord's 45 
 
 — of fermentations 76 
 
 — of milk supply 93 
 
 Cooking the curd 185 
 
 Coolers, milk 87 
 
 Cornell Univ. Agr. Expt. Station, 
 
 quoted 87, 100,109, 111, 122, 124 
 
 Cornevin, quoted 17 
 
 Correction of lactometer for tem- 
 perature 200 
 
 Cooley system 103 
 
 Cooling milk for cheese making 171 
 
 Corpuscles, colostrum 18 
 
 Corrosive sublimate 59 
 
 Cottage cheese 232 
 
 Cows' milk 16 
 
 Cows, number in United States 248 
 
Index 
 
 303 
 
 PAGE 
 
 Cows, oflficial inspection of 90 
 
 Cream 97 
 
 — cheese 200 
 
 Philadelphia 207 
 
 square 207 
 
 — composition of 97 
 
 — consistency of 95 
 
 — degree of ripeness necessary 134 
 
 — dilution in churning 148 
 
 — effect of different degrees of 
 
 ripeness on churning 137 
 
 — estimation of fat by Babcock test. 55 
 
 — for consumption 94 
 
 — frothing or swelling 148 
 
 — gathering system 41, 252 
 
 — glasses 36 
 
 — gauges 36 
 
 — over-ripened 138 
 
 — pasteurized 95 
 
 — quality of 96 
 
 — relation of ripeness to churning.. 141 
 of temperature to ripening 133 
 
 — ripening 127 
 
 — screw 118 
 
 — separation of 97 
 
 — standards for 96 
 
 — test bottles 54 
 
 — use of starter in ripening 130 
 
 — viseo 96 
 
 Creameries 236 
 
 — construction of 240 
 
 — gathered cream 252 
 
 — gravity system 237 
 
 — ground plan 239 
 
 — location of 236 
 
 — pumping system 238 
 
 — water supply of 241 
 
 Creamery butter, imitation 257 
 
 Creaming, deep setting 102 
 
 — eflSciency of centrifugal 122 
 
 — effects of delayed setting 105 
 
 of dilution on 107 
 
 — losses in deep setting 103 
 
 in shallow pan 102 
 
 — necessity for 99 
 
 — relation of centrifugal force to. - . 115 
 
 PAGE 
 
 Creaming, relation of fat globules 
 
 to 100 
 
 of inflow to complete U6 
 
 of solids not fat to 100 
 
 — — of temperature to centrifugal. 116 
 of viscosity of mUk to 101 
 
 — shallow pan loi 
 
 — systems of &8 
 
 — theory of centrifugal 113 
 
 of deep setting system 103 
 
 Creamometers 36 
 
 Curd, cutting 183 
 
 — grinding 189 
 
 — heating or cooking 185 
 
 — knives 184 
 
 — • in Babcock test 62 
 
 — matting or cheddaring 187 
 
 — mill 189 
 
 — sink 187 
 
 — salting 190 
 
 — test, Wisconsin 263 
 
 Curdling, sweet 71 
 
 Curds, fast-working 196 
 
 — floating 195 
 
 — gassy 195 
 
 Curing cheese 193 
 
 — rooms , construction of 24 4 
 
 sub-earth duct for 244 
 
 Cutting the curd 183 
 
 Dairy buildings, farm 245 
 
 — laws 269 
 
 the New York 282 
 
 — legislation 254 
 
 — markets 257 
 
 — statistics 249 
 
 Dairying, associated 250 
 
 Danish separator, large 123 
 
 small 123 
 
 — Weston separator 123 
 
 Dean, H. H., quoted 89, 167 
 
 Decinormal alkali 135, 261 
 
 Deep setting creaming 102 
 
 system 98 
 
 ■ — theory of 103 
 
 D'Isigny cheese 227 
 
304 
 
 Index 
 
 PAGE 
 
 DeLaval lactocrite 45 
 
 — separator 124 
 
 Belayed setting, effect on cream- 
 ing 105 
 
 Derbyshire cheese 218 
 
 Detachable neck test bottle 54 
 
 Determination of lactic acid 135, 261 
 
 Development of the factory system. 241 
 
 Devon milk 33 
 
 Dextrose 25 
 
 Difficult churning 147 
 
 Dilution, effect of on creaming 107 
 
 — of cream in churning 148 
 
 — separators Ill 
 
 Dioxystearic acid 23 
 
 Disease germs 71, §0 
 
 — relation of pasteurization to 90 
 
 Diseased herds, official inspection a 
 
 prevention 90 
 
 Disinfectants 78 
 
 Double Grloncester cheese 210 
 
 — necked test bottle 54 
 
 Dried casein 230 
 
 Ducts, milk 3,5 
 
 Dust, relation of bacteria to 77 
 
 Dutch cheese 232 
 
 Edam cheef^e 220 
 
 Effect of delayed setting on cream- 
 ing 105 
 
 — of dilution on creaming 107 
 
 Electricity as a germicide 79 
 
 Electrolysis 79 
 
 Emmenthaler cheese 219 
 
 Emulsion 23, 97 
 
 English Cheddar cheese 210 
 
 — cheese 210 
 
 Essential oils 20 
 
 Estimation of solids not fat 65, 260 
 
 — of total solids 65 
 
 Ewe's milk 16 
 
 Excrement, animal, relation of bac- 
 teria to 77 
 
 Experiment Station bulletins 289 
 
 — Stations, mentioned 46 
 
 Extract, rennet 178 
 
 PAQB 
 
 Factories, arrangement of cheese... 242 
 
 — butter and cheese 236 
 
 — combined butter and cheese 244 
 
 — gathered cream 252 
 
 " Factory " butter 257 
 
 Factory system, development of 251 
 
 Fahrenheit thermometer 259 
 
 Failyer and WiUard, mentioned 47 
 
 Failyer and Willard's method 47 
 
 Farm dairy buildings 245 
 
 Farrington's alkaline tablets 
 
 81. 135, 261 
 Farrington, E. H., quoted ..81, 131, 135 
 
 Fast working curds 196 
 
 Fat as a basis of value for milk in 
 cheese making 169 
 
 — globules 23 
 
 — — relation of, to churning 145 
 
 size of 23, 100 
 
 — loss of, in cheese-making 170 
 
 Pats 20 
 
 — effect of period of lactation on.. 27 
 
 — formation of 8 
 
 — gravimetric determination of 35 
 
 — non-volatile 22 
 
 — volatile 20 
 
 Ferment, preparation of artificial.. 263 
 Ferments, lactic 130 
 
 — soluble 164 
 
 Fermentations, abnormal. 71 
 
 — alcoholic 71 
 
 — butyric 71, 76 
 
 — chromogenic 71 
 
 — control of . . 1 76 
 
 — detection of 263 
 
 — germs of 67 
 
 — lactic 71, 73, 130, 171 
 
 — normal 71 
 
 — of milk 71 
 
 — peptogenic , 71, 75 
 
 — poisonous 73 
 
 — putrefactive 71, 75 
 
 — undesirable in cheese making... 194 
 
 Feser's lactoscope 44 
 
 Fibrin 23, 24 
 
 Filled cheese law 256, 276 
 
Index 
 
 305 
 
 PAGE 
 
 FiDish of 'butter 162 
 
 Fission 67 
 
 Fjord's control apparatus 45 
 
 Flavor of butter 160 
 
 relation of "wash water to . . 153 
 
 — of cheese 197 
 
 Fleischmann, quoted 17, 234 
 
 Fleshy udder 3 
 
 " Flinty break " of cheese 198 
 
 Floating curds 195 
 
 Floors, cement 240 
 
 Follicle, ultimate 3, 6 
 
 Food, influence on composition of 
 
 milk 30 
 
 Fore milk and strippings 30 
 
 Formalin 79 
 
 Formation of cheese rind 193 
 
 Formula for solids not fat, Bab- 
 cock's 260 
 
 — _ Richmond's 260 
 
 Forage, relation of bacteria to 77 
 
 Fright, effect on milk secretion 14 
 
 Frothing of cream 148 
 
 Galactose 25 
 
 Gases in milk 86 
 
 " Gassy " curds 195 
 
 Gassy ferments inNeufchatel cheese.204 
 
 Gathered cream system 252 
 
 Gerber's test 50 
 
 Germ diseases 71 
 
 Germs of disease 80 
 
 — of fermentatiou 67 
 
 Glasses, cream 36 
 
 Glassware, calibration of Babcock 
 
 test.. 265 
 
 Globules, fat 23 
 
 Gloucester cheese, single and double . 210 
 
 Glycerides 22 
 
 Goats' milk 16 
 
 Gorgonzola cheese 219 
 
 ■ Gouda cheese 224 
 
 Grain of butter 160 
 
 Gravimetric analysis 35 
 
 Gravity creaming 98, 99 
 
 — separators Ill 
 
 PAGE" 
 
 Gravity system of creamery con- 
 struction 237 
 
 Grinding the curd 189 
 
 Gruyere cheese 219- 
 
 Gauges, cream 36 
 
 Guernsey milk 33, 
 
 Gurler, H. B., quoted 132 
 
 Hansen's lactic ferment 131 
 
 Hard cheeses 199 
 
 Hay, relation of bacteria to 77 
 
 Heating the curd 185 
 
 Heeren's pioscope 4? 
 
 Herds, official inspection of diseased 90 
 
 Holding up milk & 
 
 Holstein-Priesian milk 33 
 
 Home- trade cheese 200 
 
 Horizontal separators 114 
 
 Hot iron test 265 
 
 Hydrochloric acid for ripening 
 
 cream 129 
 
 Hydrometer 37 
 
 Imitation creamery butter 257 
 
 — Swiss cheese 209 
 
 Indicator, litmus 261 
 
 — phenolphthalein 261 
 
 Infection, prevention of 7& 
 
 Inflow, relation of to complete 
 
 creaming 116 
 
 Iowa Station test 48 
 
 Ironclad tinware 83 
 
 Iron, phosphate of 25 
 
 Jersey milk 33 
 
 Jordan, Dr. W. H. , quoted 107 
 
 Jumbo separator 124 
 
 Keeping quality, relation of lactic 
 
 acid to 137 
 
 Kephir 234 
 
 Knives, curd 184 
 
 Koanig, quoted 17 
 
 Koumiss 16, 234 
 
 Lactation period, effect on composi- 
 tion of milk 27 
 
 Lactic acid 25, 74, 130 
 
306 
 
 Index 
 
 PAGE 
 
 Lactic acid, determination of... 135, 261 
 
 relation to keeping quality of 
 
 butter 137 
 
 — fermentations 71, 73, 130, 171 
 
 — ferments 130 
 
 Lactobutyrometer 43 
 
 Ijactocbrome 26 
 
 Lactometer 37 
 
 — comparison of scales 38 
 
 — corrections for temperature. .39, 260 
 
 — Board of Health 259 
 
 — Quevenne 260 
 
 — scales, comparison of 260 
 
 Lactocrite 45 
 
 Lactoprotein 26 
 
 Jjactoscope 44 
 
 Lactose 25 
 
 Lancashire cheese 218 
 
 Laxirie acid 23 
 
 Laurin 20 
 
 Law, dairy 269 
 
 — filled cheese 256, 276 
 
 — oleomargarine 255, 269 
 
 — the New York dairy 282 
 
 " Leaky" cheese 202 
 
 LeFeldt and Lentsch, mentioned... 112 
 
 Leffman and Beam, mentioned 154 
 
 Legal standards for milk ...93, 254. 269 
 
 cream 96 
 
 Legislation, dairy 254 
 
 Leicestershire cheese 218 
 
 Lentsch and LeFeldt, mentioned . . . 112 
 
 Limburger cheese 207 
 
 Lime, phosphate of 25 
 
 Litmus test 261 
 
 Loss of fat in cheese making 170 
 
 Lymphatics 3 
 
 Magnesia, phosphate of 25 
 
 Males, milk from 10 
 
 Mammae 1 
 
 Mammalia 1 
 
 Mammary gland 1 
 
 Manns, A. Q-. , mentioned 134 
 
 — acid test 134 
 
 Marchand's lactobutyrometer 43 
 
 PAGB 
 
 Mares' milk 16 
 
 Marketing butter 157 
 
 Markets, dairy 257 
 
 Marschall rennet test 174, 264 
 
 Maternity, effect on milk secretion. 9 
 
 Matting 187 
 
 Meadow Sweet cheese 209 
 
 Membrane, formation of, in cheese 
 
 making 185 
 
 Method of Pailyer and Willard 47 
 
 Metric system 267 
 
 Milch Zeitung 123 
 
 Milk, aeration of 86, 173 
 
 — aerators 87 
 
 — albuminoids of 23 
 
 — ash of , 25 
 
 — asses 16 
 
 — Ayrshire 33 
 
 — bacteria 69 
 
 — bad flavors in 91 
 
 — bitter 71 
 
 — bottles 90 
 
 — cistern 5 
 
 — composition of 17 
 
 — condensed 253 
 
 — constituents 16 
 
 — control of animal over secretion 
 
 of 14 
 
 — coolers 87 
 
 — cooling for cheese making 171 
 
 — defined 1 
 
 — jDevon 33 
 
 — difference in first and last drawn. 30 
 
 — — in night's and morning's 28 
 
 — duets 3, 5 
 
 — duration of flow 11 
 
 — effect of breed on composition.. 32 
 
 — — — age on composition 31 
 
 of period of lactation on 27 
 
 — ewe's 16 
 
 — fats 20 
 
 — fermentations of 71 
 
 — from males 10 
 
 — from organs other than tha 
 
 mammary gland W 
 
 — from virgin animals 10 
 
Index 
 
 307 
 
 PAGE 
 
 Milk, gases in 86 
 
 — goats' 16 
 
 — Guernsey 33 
 
 — holding up 5 
 
 — Holstein-Friesian 33 
 
 — influeneeof food on composition. 30 
 Milking, frequency of 13 
 
 — importance of complete 12 
 
 of regularity 13 
 
 — rapidity of 14 
 
 Milk, Jersey 33 
 
 — legal standards for 254,269 
 
 — mare's . , 16 
 
 — over-ripeness for cheese making .196 
 
 — paying for, according to percen- 
 
 tage of fat 169 
 
 — Quality of, for cheese making 164 
 
 — relation of viscosity to churn- 
 
 ing 140 
 
 — ripening for cheese making 172 
 
 — ropy 71 
 
 — sampler, ScoveU's aliquot 60 
 
 — selection for pasteurizing 82 
 
 — secretion 7 
 
 control of animal over 14 
 
 effect of fright on 14 
 
 of maternity on 9 
 
 of pregnancy on 12 
 
 of sexual excitement on , . , 14 
 
 relation of hlood to 11 
 
 of nervous organization to. 14 
 
 of parturition to 9 
 
 — Short Horn 33 
 
 — skimmed 229 
 
 — slimy 71 
 
 — solids 16 
 
 concerned in making cheese . . 163 
 
 — specific gravity of 19 
 
 — sterile 66, 70 
 
 — straining 85 
 
 — sugar 25, 231 
 
 formation of 8 
 
 — supply, control of 93 
 
 — tests, Bahcock 49 
 
 Beimling 50 
 
 butyrometer 51 
 
 Milk tests, Cochran's 49 
 
 Failyer andWillard's 47 
 
 Gerber's 50 
 
 — — history 36 
 
 Iowa Station 48 
 
 Parsons' 48 
 
 Short's 48 
 
 — thief 59, 60 
 
 — variations in quality 27 
 
 — viscosity of 101 
 
 Mill, curd 189 
 
 Molds 67 
 
 Monrad, J. H., quoted 207. 219, 233 
 
 Monrad's rennet test 174, 264 
 
 Moore, quoted 132 
 
 Mottled butter 156 
 
 Myristic acid 22 
 
 Myseost 232 
 
 ^ alkali 135 
 
 Nervous organization, relation to 
 
 milk secretion 15 
 
 Neufchatel cheese, American 203 
 
 Xeumann, mentioned 60 
 
 New York dairy law 282 
 
 Night's and morning's milk, difiEer- 
 
 ence in composition 28 
 
 Nipple 2 
 
 Nitrate of soda 60 
 
 Non-volatile fats 22 
 
 Normal fermentations 71 
 
 Odor, animal 86 
 
 Of&cial inspection of cows 90 
 
 Ohlsson's test bottle 54 
 
 Oil test chum 42 
 
 Oleic acid 22 
 
 Olein 22 
 
 Oleomargarine 255 
 
 — law 255, 269 
 
 Oliver. John 17 
 
 Optimum temperature 68 
 
 Over - ripened cream, bad effects 
 
 of 138 
 
 Over-ripe milk in cheese making . . .196 
 Oxidation in cream-ripening 129 
 
308 
 
 Index 
 
 PAGE 
 
 , butler 158 
 
 Packing butter 157 
 
 Palmitic acid 22 
 
 Palmitin 22 
 
 Paper coil method, Adams' 36 
 
 — parchment 159 
 
 Parmesan cheese 228 
 
 Parsons, C. L., mentioned 48 
 
 Parsons' method 48 
 
 Parturition, relation of to milk 
 
 secretion. 9 
 
 Pasteurization 79, 90 
 
 — apparatus 81 
 
 — selection of milk for 82, 262 
 
 Pasteurized cream 96 
 
 Patrick, Geo. E., mentioned 48 
 
 Paying for milk according to per- 
 centage of fat ; 169 
 
 Peptogenic fermentations 71, 75 
 
 Phenolphthalein 135, 261 
 
 Philadelphia cream cheese 207 
 
 Phosphate of iron 25 
 
 — of lime 25 
 
 — of magnesia 25 
 
 — of potash 25 
 
 Picnic cheese 203 
 
 Pineapple cheese 203 
 
 Pioscope 43 
 
 Poisonous fermentations 73 
 
 Pont L'Eveque cheese 227 
 
 Portdu Salut cheese 228 
 
 Potash, caustic 60 
 
 — phosphate of 25 
 
 Potassium bichromate 59 
 
 — chloride 25 
 
 Pot cheese 232 
 
 Preservaline 60 
 
 Preservatives in composite sam- 
 pling 59 
 
 Pregnancy, effect of on milk secre- 
 tion 12 
 
 Preparation of artificial starter 263 
 
 Prepared cheese 209 
 
 Press, cheese 192 
 
 Pressed tinware 84 
 
 Pressing cheese 191 
 
 PAGE 
 
 Prevention of infection 76 
 
 Primost 232 
 
 Print butter 159 
 
 Process butter -. 257 
 
 Ptomaines 73 
 
 Pumping system of creamery con- 
 struction 238 
 
 Putrefactive fermentations 71, 75 
 
 Quality of butter 159 
 
 — of cream 96 
 
 — of milk for cheese making 164 
 
 legal standards for 93 
 
 Quevenne lactometer 38, 260 
 
 Rancid butter 20 
 
 References 289 
 
 Rennet 164, 176 
 
 — extract 178 
 
 — relation of temperature to ac- 
 
 tivity of 177 
 
 — test 173,264 
 
 Marschall's 174 
 
 Monrad's 174 
 
 Renovated butter 257 
 
 Reports and bulletins of Agr. Exp. 
 
 Stations 289 
 
 Richmond, quoted 18 
 
 Richmond's formula for solids not 
 
 fat 260 
 
 Rind of cheese 198 
 
 formation of 193 
 
 Ripeness, churning cream of differ- 
 ent degrees 137 
 
 — of cream, relation to churning. . .141 
 
 Ripening cream r; ^ 127 
 
 amount necessary 134 
 
 relation of temperature to. . . .133 
 
 use of starters in 130 
 
 — of milk for cheese making 172 
 
 Ropy milk 71 
 
 Roquefort cheese 16', 224 
 
 Rules and tests, useful 259 
 
 Russell, H. L., quoted 81, 95, 131 
 
 Russian separator 125 
 
 Rusty tinware 84 
 
Index 
 
 309 
 
 PAGE 
 
 202 
 
 Salt 156 
 
 Salting butter 154 
 
 — cheese 190 
 
 Salicylic acid 79 
 
 Sampler, Scovell aliauot mUk , 60 
 
 Scale of perfection for butter 163 
 
 foroheese 198 
 
 Schmierkase 232 
 
 Schweitzer cheese 219 
 
 SooveU aliauot milk sampler 60 
 
 Secretion of milk 7 
 
 Selecting milk for pasteurizing 82 
 
 Separation, theory of centrifugal. . . 113 
 Separator, adjustable 123 
 
 — Alexander Jumbo 124 
 
 — Alpha 124 
 
 — Arnold's 123 
 
 — Columbia 123 
 
 — Danish Weston 123 
 
 — De Laval 124 
 
 — dilution Ill 
 
 — gravity Ill 
 
 — horizontal 114 
 
 — large Danish 123 
 
 — mecha'l contrivances in bowl 'Of.. 119 
 
 — medium Brown- 123 
 
 — Sharpies' Kussian 125 
 
 — slime 115 
 
 — small Danish 123 
 
 — system 98 
 
 — United States 125 
 
 ~ Victoria 123 
 
 Setting, effect of delay on creaming. 105 
 
 — milk for cheese making 181 
 
 Sewers 241 
 
 Sexual excitement, effect of, on 
 
 mUk secretion 6 
 
 Shallow pai^ creaming 101 
 
 system 98 
 
 Sharpies' Russian separator 125 
 
 Short, F. G., mentioned 47 
 
 Short-horn mUk 33 
 
 Short's method 47 
 
 Single Gloucester cheese 210 
 
 Size of fat globules 100 
 
 PAGE 
 
 Sink, curd 187 
 
 Skimmed cheese 200, 256 
 
 — milk 329 
 
 estimation of fat byBabcock 
 
 test 56 
 
 test bottle 54 
 
 Skimmer 102 
 
 Skimming 102 
 
 Slime, separator 115 
 
 Slimy milk 71 
 
 " Sloppy " cheese 202 
 
 Soda, caustic 60 
 
 Sodium chloride 25 
 
 — nitrate 60 
 
 Soft cheese 199 
 
 Solids concerned in making cheese. .163 
 
 — estimation of total 65 
 
 — not fat, estimation of 65, 260 
 
 — — — relation to creaming 100 
 
 — total, determinatiom of '. . 35 
 
 Soluble ferments 164 
 
 Soxhlet's method 45 
 
 Speoiflo gravity 19, 37 
 
 Specks, black, in Babcock test 63 
 
 Speed of bowl, relation of, to com- 
 plete creaming .- 40, 116 
 
 Sphincter muscle 4, 5 
 
 Spirillum 67 
 
 Spore 68 
 
 Square cream cheese 207 
 
 Standards for cream 96 
 
 for mUk, legal 93, 254, 269 
 
 "Standing up" quality of butter 128 
 
 Starters 130, 175 
 
 — preparation of 263 
 
 "State Brands" 256 
 
 Statistics, dairy 249 
 
 Stearic acid 22 
 
 Sterile milk 66, 70 
 
 Sterilization 79 
 
 Stilton cheese 210 
 
 Stirred-curd cheese 200 
 
 Storch, mentioned 131 
 
 Strainers 85 
 
 Straining mUk 85 
 
 Streaked butter 166 
 
310 
 
 Index 
 
 PAGE 
 
 Strippings and fore milk 30 
 
 Sub-earth duet for curing-rooms 244 
 
 Sugar of mUk 25, 231 
 
 Sulphuric acid 62 
 
 Sunlight, effect on cleanliness 84 
 
 Surface tension 23, 97 
 
 Sweet cream butter 128, 137 
 
 — curdling 71 
 
 Swelling of cream 148 
 
 Swiss cheese 219 
 
 imitation 209 
 
 System, metric 267 
 
 Tablets, Farrington's alkaline.. 135, 261 
 
 Taints, to detect 263 
 
 Teat 2 
 
 Temperature, best for churning 141 
 
 for deep setting creaming.... 103 
 
 for shallow pan creaming 101 
 
 — — for washing butter 151 
 
 — correction for lactometer 260 
 
 — effect of, on activity of rennet. . .177 
 
 — for ripening cream 133 
 
 — relation of, to centrifugal sep- 
 
 aration 116 
 
 of , to churning 141 
 
 — rise of, in churning 149 
 
 Testing Babeoek glassware 57 
 
 Tests and rules, useful 259 
 
 Test, Babcock 49 
 
 calibration of glassware , 265 
 
 — Beimling 50 
 
 — bottle, Babcock 54 
 
 B. and W 54 
 
 — — cream 54 
 
 detachable neck 54 
 
 double-necked 54 
 
 Ohlsson 54 
 
 skimmed milk 54 
 
 — butyrometer 51 
 
 — chum 41 
 
 — Cochran's 49 
 
 — Failyer and Willard's 47 
 
 — Gerber's 50 
 
 ~ history of milk 36 
 
 — hot iron 265 
 
 "- Iowa Station 48 
 
 PAGB 
 Test, litmus 261 
 
 — Manns' acid 134 
 
 — Parsons' 48 
 
 — phenolphthalein 261 
 
 — rennet 173, 264 
 
 — Short's 47 
 
 — Wisconsin curd 263 
 
 Texture of butter 128,160 
 
 relation of wash- water to.. 152 
 
 — of cheese 197 
 
 Theory of centrifugal separation... 113 
 Thermometer, Fahrenheit 259 
 
 — Centrigrade 259 
 
 — scales, comparison of 259 
 
 Tiemann, mentioned IM 
 
 Tinware, ironclad 83 
 
 — pressed 84 
 
 — rusty 84 
 
 — washing 84 
 
 Tissue, connective 3 
 
 Total solids, determination of 35 
 
 estimation of 65, 260 
 
 Truckle cheese 203 
 
 Turbine, steam, Babcock 53 
 
 Tubercle bacillus 80 
 
 Tyrotoxicon 73 
 
 Udder 2 
 
 Ultimate follicle 3,6 
 
 United States separator 125 
 
 type of separator 120 
 
 Urea 26 
 
 Useful rules and tes:s 259 
 
 Utensils, cleaning 77 
 
 Van Slyke, Dr. L. L., mentioned... 31 
 
 quoted 165, 170 
 
 Vermont Agr. Expt. Station quoted . 109 
 
 Vessels, cleaning 77. 
 
 Victoria separator 123 
 
 Virgin animals, milk from 10 
 
 Viscogen 95 
 
 — preparation of 262 
 
 Visco-cream 96 
 
 Viscosity of milk 97 
 
 relation of, to churning 140 
 
Index 
 
 311 
 
 PAGE 
 
 Viscosity of milk relation to cream- 
 ing '. 101 
 
 Volatile fats 20 
 
 source of 21 
 
 Von Klenze, mentioned 199 
 
 Washing butter 150 
 
 — tinware 84 
 
 Water supply of creameries 241 
 
 Wells 241 
 
 Wensleydale cheese 219 
 
 "Wet" cheese 202 
 
 Whey 229 
 
 PAGE 
 
 Whey cheese 232 
 
 Wheyn 234 
 
 White specks in butter 138 
 
 Williams, Jesse, mentioned 251 
 
 Wiltshire cheese 210 
 
 Wire strainers, size of 85 
 
 Wisconsin curd test 263 
 
 Woll, ¥. W., quoted 52 
 
 Working butter 153 
 
 Yeasts 67 
 
 Young America cheese 203 
 
THE RURAL SCIENCE SERIES 
 
 Includes books which state the underlying principles 
 of agriculture in plain language. They are suitable 
 for consultation alike by the amateur or professional 
 tiller of the soil, the scientist or the student, and are 
 freely illustrated and finely made. 
 
 The following volumes are now ready: 
 
 THE SOIL. By P. H. King, of the University of Wisconsin. 303 pp. 45 
 illustrations. 
 
 THE FERTILITY OF THE LAND. By I. P. Pobebts, of Cornell Univer- 
 sity. 421 pp. 45 illustrations. 
 
 THE SPRAYING OF PLANTS. By E. G. Lodeman, late of Cornell Uni- 
 versity. 399 pp. 92 illustrations. 
 
 MILK AND ITS PRODUCTS. By H. H. WiNO, of Cornell University 
 311 pp. 43 illustrations. 
 
 THE PRINCIPLES OF FRUIT-GROWING. By L. H. Bailey. 516 pp. 
 120 illustrations 
 
 BUSH-FRUITS. By F. W. Oabd, of Rhode Island College of Agricultur* 
 and Mechanic Arts. 537 pp. 113 illustrations. 
 
 FERTILIZERS. By E. B. Voorhees, of New Jersey Experiment Station. 
 332 pp. 
 
 THE PRINCIPLES OF AGRICULTURE. By L. H. Bailey. 300 pp. 92 
 illustrations. 
 
 IRRIGATION AND DRAINAGE. By F. H. Kino, University of Wisconsin. 
 502 pp. 163 illustrations. 
 
 THE FARMSTEAD. By I. P. Kobeets. 350 pp. 138 illustrations. 
 
 RURAL WEALTH AND WELFARE. By Geobqe T. Faikchild, Ex-Presi- 
 dent of the Agricultural College of Kansas. 381 pp. 14 charts. 
 
 THE PRINCIPLES OF VEGETABLE-GARDENING. By L. H. Bailey. 
 468 pp. 144 illustrations. 
 
 THE FEEDING OF ANIMALS. By W. H. Jobdan, of New York State 
 Experiment Station. 450 pp. 
 
 FARM POULTRY. By Gboege C. Watson, of Pennsylvania State College. 
 341 pp. 
 
 THE FARMER'S BUSINESS HANDBOOK. By L P. Robbbts, of Cornel] 
 University. 300 pp. 
 
 THE CARE OF ANIMALS. By Nelson S. Mayo, of Kansas State Agri- 
 cultural College. 458 pp. 
 
 THE HORSE. By I. P. Robebts, of Cornell University. 413 pp. 
 
 New volumes will be added from time to time to 
 the Rural, Science Series. The following are in 
 preparation : 
 
 PHYSIOLOGY OF PLANTS. By J. C Abthub, Purdue University. 
 
 THE PRINCIPLES OF STOCK BREEDING. By W. H. Beeweb, of YaU 
 
 University. 
 PLANT PATHOLOGY. By B. T. Galloway and assoelates, of U. S. Depart 
 
 ment of Agriculture. 
 THE POME FRUITS (Apples, Pears, Quinces). By L. H. Bailey. 
 
THE GARDEN-CRAFT SERIES 
 
 Comprises practical handbooks for the horticultur- 
 ist, explaining and illustrating in detail the various 
 important methods which experience has demon- 
 strated to be the most satisfactory. They may be 
 called manuals of practice, and though all are pre- 
 pared by Professor Bailet, of Cornell University, 
 they include the opinions and methods of success- 
 ful specialists in many lines, thus combining the 
 results of the observations and experiences of nu- 
 merous students in this and other lands. They are 
 written in the clear, strong, concise English and in 
 the entertaining style which characterize the author. 
 The volumes are compact, uniform in style, clearly 
 printed, and illustrated as the subject demands. 
 They are of convenient shape for the pocket, and 
 are substantially bound in flexible green cloth. 
 
 THE HORTICULTURIST'S RULE BOOK. By L. H. H&ILST. 112 tW. 
 
 THE NURSERY-BOOK. S7 L. E. Bailxt. 365 pp. 1S2 UluatrBtloiu. 
 
 PLANT-BREEDING. By L. H. BAiiiKT. 293 pp. 20 illu8tr»tloi«. 
 
 THE FORCING-BOOK. By L. H. Bailbt. 266 pp. 88 illustMtiom. 
 
 GARPEN-MAKING. By L. H. Bailbt. 417 pp. 256 UlnstrationB. 
 
 THE PRUNING-BOOK. By L. H. Bailet. 645 pp. 331 UlnstratioM. 
 
 THE PRACTICAL GARDEN-BOOK. By C. E. HuHH »nd L. H. BailbY. 
 260 pp. Many marginal cuU. 
 
WORKS BY PROFESSOR BAILEY 
 
 'HE EVOLUTION OF OUR NA^ 
 
 TIVE FRUITS. By L. H. BAILEY, Pro- 
 fessor of Horticulture in the Cornell University. 
 
 414 PAOCS— ISB ILLUSTRATIONS — $2.00 
 
 In this entertaining volume, the origin and de- 
 velopment of the fruits peculiar to North America 
 are inquired into, and the personality of those horti- 
 cultural pioneers whose almost forgotten labors 
 have given us our most valuable fruits is touched 
 upon. There has been careful research into the 
 history of the various fruits, including inspection 
 of the records of the great European botanists who 
 have given attention to American economic botany. 
 The conclusions reached, the information presented, 
 and the suggestions as to future developments, can- 
 not but be valuable to any thoughtful fruit-grower, 
 while the terse style of the author is at its best in 
 his treatment of the subject. 
 
 The Evolution o* our Native Pbuits discusses The Rise ot 
 the American Grape (North America a Natural Vineland, Attempts 
 to Cultivate the European Grape, The Experiments of the Dufours, 
 The Branch of Promise, John Adlum and the Catawba, Rise of 
 Commercial Viticulture, Why Did the Early Vine Experiments Fail ? 
 Synopsis of the American Grapes) ; The Strange History of th^Mul- 
 berries (The Early Silk Industry, The "Multicaulis Craze,") ; Evolu- 
 tion of American Plums and Cherries (Native Plums in General, 
 The Chickasaw, Hortulana, Marianna and Beach Plum Groups, 
 Pacific Coast Plum, Various Other Types of Plums, Natwe Cherries, 
 Dwarf Cherry Group ) ; Native Apples (Indigenous Species, Amelio- 
 ration has begun); Origin of American Raspberry-growing (Early 
 American History, Present Types, Outlying Types) ; Evolution of 
 Blackberry and Dewberry Culture (The High-bush Blackberry and 
 Its Kin, The Dewberries, Botanical Names); Various Types of 
 Berry-like Fruits (The Gooseberry, Native Currants, Juneberry, 
 Buffalo Berry, Elderberry, High-bush Cranberry, Cranberry, Straw- 
 berry); Various Types of Tree Fruits (Persimmon, Custard-Apple 
 Tribe, Thorn-Apples, Nut-Fruits) ; General Remarks on the Improve- 
 ment of our Native Fruits (What Has Been Done, What Probably 
 Should Be Done). 
 
WORKS BY PROFESSOR BAILEY 
 
 ESSONS WITH PLANTS: Sugge.- 
 tions for Seeing and Interpreting Some of 
 the Common Forms of Vegetation. By L. 
 
 H. BAILEY, Professor of Horticulture in the Cornell 
 University, with delineations from nature by W. S. 
 HOLDSWORTH, of the Agricultural College of 
 Michigan. 
 
 SECOND EOITION~48l PACES— 446 ILLUSTRATION*— I C MO— 
 CLOVH'SI.IO NET 
 
 There are two ways of looking at nature. The 
 old way, wMch you have found so unsatisfactory, 
 was to classify everything — to consider leaves, roots, 
 and whole plants as formal herbarium specimens, 
 forgetting that each had its own story of growth 
 and development, struggle and success, to tell. 
 Nothing stifles a natural love for plants more effect- 
 ually that! that old way. 
 
 The new way is to watch the life of every grow- 
 ing thing, to look upon each plant as a living 
 creatui-e, whose life is a story as fascinating as the 
 story of any favorite hero. "Lessons with Plants" 
 is a book of stories, or rather, a book of plays, for 
 we can see each chapter acted out if we take the 
 trouble to look at the actors. 
 
 " I have spent some time in most delightful examination of it, and the- 
 longer I look, the better I like it. I find it not only full of interest, but 
 eminently suggestive, I know of no book which begins to do so much to 
 open the eyes of the student— whether pupil or teacher — to the wealth of 
 meaning contained in simple plant forms. Above all else, it seems to be 
 full of suggestions that help one to learn the language of plants, so they 
 may talk to him."- Dakwin li. Babdwell, Superintendent of Schools, Bing- 
 hwtnton. 
 
 "It is an admirable book, and cannot fail both to awaken interest in 
 the subject, and lo serve as a helpful and reliable guide to young students 
 of plant life. It will, I think, fill an important place in secondary schools, 
 and comes at an opportune time, when helps of this kind are needed and 
 eafiierly sought."— Professor V. M. Spalding, University of Michigan. 
 
 FIRST LESSONS WITH PLANTS 
 
 An Abridgement of the above. 117 pages — 116 illustrs' 
 tions — 40 cents net. 
 
WORKS BY PROFESSOR BAILEY 
 
 B 
 
 OTANY : An Elementary Text for Schools. 
 
 By L. H. BAILEY. 
 
 315 PACES— aOO ILLUSTRATIONS— • I.I O NIT 
 
 "This book is made for the pupil: 'Lessons With Plants' 
 was made to supplement the work of the teacher." This is the 
 opening sentence of the preface, showing that the book is a 
 companion to "Lessons With Plants," which has now become a 
 standard teacher's book. The present book is the handsomest 
 elementary botanical tezt-book yet made. The illustrations 
 illustrate. They are artistic. The old formal and unnatural 
 Botany is being rapidly outgrown. The book disparages mere 
 laboratory work of the old kind: the pupil is taught to see things 
 as they grow and behave. The pupil who goes through this book 
 will understand the meaning of the plants which he sees day 
 by day. It is a revolt from the dry-as-dust teaching of botany. 
 It cares little for science for science' sake, but its point of view 
 is nature-study in its best sense. The book is divided into four 
 ■parts, any or all of which may be used in the school: the plant 
 Itself; the plant in its environment; histology, or the minute 
 fltructure of plants ; the kinds of plants (with a key, and de- 
 scriptions of 300 common species). The introduction contains 
 advice to teachers. The book is brand new from start t« 
 ifinish. 
 
 "An exceedingly AttrMtiTe text-book."— f durational Btvitu. 
 "It !■ a ichool book of the modem methods."— TAe Dial. 
 
 "It would be hard to find A better mannAl for schools or for Indl* 
 'ViduAl use."— TAe Outlook. 
 
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