^* .-'^^fA'. \/ /^fe\ •^^.,** y^£% \.J "-^ ^'.f.^i' Y,* t°^ "o. "^^r..' .\0 ;' cfl K: %/ .^^\ \/ ^^' %^^ .*S ^ .<^ ^. lV ... -<. -•• A- „.„^ -^. 3-/ '^^ '^0' jP-n^ ^ .^' ^0^ .^'\ v^^^^^' lO* * » THE AUTHOR'S SON Reared from birth en milk pasteurized and modified in the home Milk and Milk Products in the Home A Book Intended for Students in Home Economics and for Housekeepers in General BY JOHN MICHELS, B.S.A., M.S. Professor of Dairying and Animal Husbandry in the New York State School of Agriculture Author and Publisher of "Dairy Farming," "Market Dairying and Milk Products," "Creamery Buttermaking" ILLUSTRATED FARMINGDALE, NEW YORK Published by the Author 1915 All Rights Reserved ->\.<^ COPYRIGHT, BY JOHN MICHELS 1915 AUG -9 1915 J^^^ ^ ©CI.A411055 PREFACE Tlie cow lias been properly called the foster mother of the human race. Her products, in im- portance, overshadow those from any other source. Through all the centuries, from ancient times to the present, milk and milk products have constituted an important part of the human dietary. In modern times the use of milk has become especially import- ant because thousands of babies are forced to rely upon it as their only source of food. Good milk is an economical and easily digest- ible food, and so are many of the products made from it. To impress this fact upon housekeepers and students in home economics has been one of the aims of this book. There is also need of better familiarizing consumers with the various grades of market milk and milk products and to show their uses and value in the dietary. Unfortunately a great deal of milk placed upon the market is unsafe as a food because of ignor- ance and carelessness in the methods employed in its production and handling. That milk is often a dangerous food is amply attested by the hundreds of babies which it destroys annually, and by the numerous milk-borne epidemics of contagious dis- eases such as tuberculosis, typhoid fever, diphtheria etc. — diseases which not only affect babies and children but people of all ages. Special efforts have 6 MILK AND MILK PRODUCTS IN THE HOME therefore been made in this book to outline simple, practical home methods of treating and handling milk by which it is made a safe food for babies and adults. For many years part of the author's time has been given to teaching dairy subjects to students in home economics. The experience thus gained has been of material value in several ways : it has im- pressed upon him the conviction that the average housekeeper knows far too little of the relation which milk bears to the welfare of the family; it has also materially assisted him in so arranging and treating the subject matter as to make the book especially adaptable as a text for students in home economics. John Michels June 1, 1915. 0~ T TiiiiiiMiiiiiiiiiiiiiiiiiiiiiiiiniiii \HE COW is the I foster mother of I the human race. ,1 From the day of the ancient Hindoo to this time have the thoughts of men turned to this kindly and beneficent creature as one of the chief sustain- ing forces of human life. W. D. HOARD Et -B TABLE OF CONTENTS Page Chapter I Composition of Milk 9 Chapter II Milk as a Food 13 Chapter III Physical Properties of Milk and Cream 16 Chapter IV Common Milk Bacteria 19 Chapter V Care of Milk in the Home. ... 23 Chapter VI Market Classes of Milk 27 Chapter VII Milk-Borne Disease Bacteria . . 33 Chapter VIII Pasteurization of Milk and Cream 37 Chapter IX Modified Milk 44 Chapter X Condensed and Evaporated Milks 53 Chapter XI Sour Milk 56 Chapter XII Whey, Skimmilk and Cottage Cheese 62 Chapter XIII Cream 66 Chapter XIV Ice Cream 71 Chapter XV Fancy Cheese 76 Chapter XVI Fancy Dairy Dishes 79 Chapter XVII Butter and Oleomargarine ... 82 Chapter XVIII Common Cheese 89 Chapter XIX Production of Clean, Whole- some Milk 92 Index 99 CHAPTER T COMPOSITION OF MILK Cow's milk has an average composition as follows: Water 87.2 per cent. Casein 2.8 per cent. Albumen 0.6 per cent. Milk sugar 4.9 per cent. Butterf at 3.8 per cent. Ash 0.7 per cent. Enzymes Trace 100.0 per cent. The term ''per cent." applied to the constituents of milk means pounds in 100 pounds. Thus, 3.0 per cent, of casein means that there are three pounds of casein in a hundred pounds of milk. In speaking of milk, the terms "four per cent, milk," ''five per cent, milk," etc., are frequently used, meaning milk containing four and five per cent, butterf at, respectively. Such terms as "whole milk" and "normal milk" are often used in place of the term "milk," but they mean exactly the same thing. MILK CONSTITUENTS Water. The water of milk is identically the same as any chemically pure water. While milk is a fluid substance, it contains less water than many common vegetables. Parsnips, string beans and as- paragus, for example, contain more water than aver- age market milk. 9 lO MILK AND MILK TRODUCTS IN THE HOME Casein and Albumen. These substances belong to the group of nutrients known as proteids. They are rich in nitrogen and, like the lean of meat and the white of egg, serve the purpose of building up muscles, hair and tendons, and may also supply heat and energy. Casein is a white, insoluble substance suspended in milk in an extremely finely divided condition. It is the most important tissue building constituent of milk and forms the basis of an almost endless variety of cheese. The curdling of milk is due to the casein, which is easily precipitated by acids. Thus, in the ordinary souring of milk enough acid is eventually produced to curdle (coagulate) it. Rennet extract also curdles the casein and, there- fore, the milk of which the casein is a part. Albumen is a soluble substance which is not affected by rennet or acids but curdles when heated to 170° F. In composition it very closely resembles casein, differing from it chiefly in being rich in sul- phur while the casein is rich phosphorous. Milk Sugar. This constituent, unlike the casein and albumen, contains no nitrogen. It belongs to the group of nutrients known as carbohydrates, whose purpose in nutrition is to supply heat and energy and to store reserve energy in the form of fat. As a source of energy, carbohydrates are equal to proteids, pound for pound. Milk sugar, which is known chemically as lactose, has the same composition as cane sugar; it differs from this, however, in being more digestible and COMPOSITION OF MILK II only faintly sweet. When milk sours part of the sugar is changed into lactic acid through the agency of bacteria, which are described on page 19. Butterfat. This substance belongs to the third great group of nutrients known as fats, which con- tain the same chemical elements as the carbohy- drates but in different proportions. As a food, one pound of fat is equal to two and one-fourth pounds of carbohydrates. Fats play the same part in nutri- tion as the carbohydrates, supplying heat and en- ergy and storing surplus energy in the form of fat. Butterfat is a compound fat, being made up of at least nine distinct fats. The most important of these fats is butyrin, which is present in no veg- etable or other animal fats. Butyrin is volatile and has a very pleasing aroma. Figure 1 shows the appearance of butterfat when viewed in milk under a high power microscope. It Figure 1— Butterfat globules in milk. Dark spots are bacteria- some in chains (Russell) 12 MILK AND MILK PRODUCTS IN THE HOME; is suspended in the form of extremely small globules numbering about 100,000,000 per drop of milk. It is this fine division of the butterfat, together with its large percentage of soluble fats, which, to a large extent, accounts for its superior digestibility. Another matter which aids in the digestion of but- terfat is its low melting point. Butterfat melts at about 90° F. while other common animal fats melt at considerably higher temperatures. Ash. This is the mineral portion of milk and exists mostly in solution. It is composed of lime, magnesia, potash, soda, prosphoric acid, chlorine, sulphuric acid and iron. Its chief purpose in nutri- tion is to build up bones, teeth and blood. Enzymes. These are chemical ferments which aid in digestion. It has been shown by experiments that ordinary foods when taken in conjunction with milk are better digested than when taken without the milk. The greater digestibility so found is credited to the digestive ferments contributed by the milk. One of the objections to boiling milk is the destruction of its enzymes by the high tempera- ture. Milk Solids. The milk solids, sometimes spoken of as "total solids," include all of the milk but the water. If a sample of milk be kept at the boiling temperature until all the water has been evaporated, the dry, solid residue constitutes the solids of milk. The solids less the fat are known as the ''solid not fat" or the "non fatty" solids. CHAPTER II MILK AS A FOOD As shown in the preceding chapter, milk is a com- plete food, containing all the elements necessary to sustain life ; moreover, it contains these elements in proper proportions and in easily digestible and as- similable form. Milk is also greatly valued for its paiatability. It is these valuable qualities which have made milk so prominent in the diet of all classes of people. For growing children, milk has no satisfactory substi- tute ; for thousands of babies deprived of their moth- er's milk, it is indispensable. Milk is rich in proteids and mineral matter, ma- terials required in building up muscles and bones. This is why milk is so essential for normal growth and body development in children. Unfortunately too many consumers look upon milk as a luxury. As a matter of fact, at prevailing prices, milk is a cheap food, especially when com- pared with eggs and meat. One quart of good milk is equal to about eight eggs or three-fourths of a pound of steak. Variations in Quality. Wide variations exist at present in the quality of market milks. Analyses of normal market milks show a variation in fat content of from 3 to 5.5 per cent. And there is a great deal of milk sold illegally containing only 2.5 per cent, butterfat. 13 14 MILK AND MILK PRODUCTS IN THE HOME Particularly wide are the variations in the quality of milk from individual cows as shown by the fol- lowing maximum and minimum composition: Per Cent. Maximum Minimmn Water 90.69 Butterf at Casein Albumen Sugar Ash Quality as Affected by Breeds. The quality of milk differs markedly with different breeds of cattle. Some breeds produce rich milk, others relatively poor milk, as shown by the following table : 0.69 80.32 6.47 1.67 4.23 1.79 1.44 .25 6.03 2.11 1.21 .35 BREED BUTTER- FAT CASEIN ALBUMEN MILK SUGAR ASH Ayrshire . Guernsey. Jersey Holstein.. Per cent. 3.8 5.4 5.7 3.4 Per cent. 2.5 2.9 3.0 2.4 Per cent. 0.55 0.60 0.60 0.50 Per cent. 4.9 5.0 5.0 4.8 Per cent. 0.70 0.75 0.75 0.65 With the wide variations existing in the quality of milk it should be paid for according to its quality. It is fair to say that, in point of food value, a quart of milk containing 5.5 per cent, butterfat is worth at least fifty per cent, more than a quart containing only 3 per cent, butterfat. In other words, when a consumer pays twelve cents a quart for 5.5 per cent, milk, he is paying no more for the actual amount of food he gets than when he pays eight cents a quart for 3 per cent. milk. MILK AS A FOOD 15 It is as much a business proposition for consumers to consider the food value of milk as it is for them to consider the quality of the cloth they buy. Value of Clean, Wholesome Milk. The real value of milk cannot be judged entirely from its composi- tion. For babies especially, cleanliness and purity should chiefly determine the price to pay for milk. With milk as with many other commodities, the best is the cheapest in the long run. It costs more to produce clean milk than just common milk and con- sumers must expect to pay for the extra expense in- volved in furnishing clean, wholesome milk. Various Uses. Milk is used in so many different ways that it is difficult to see how any family can get along without it. Its use in custards, puddings, cakes, cookies, muffins, bread, biscuits, gravies, soups, chowders and scores of other ways, makes milk well-nigh indispensable. It is not the province of this book to discuss the uses of milk in cooking because this information can be obtained from nearly all cook books. CHAPTER III PHYSICAL PROPERTIES OF MILK AND CREAM Specific Gravity. By specific gravity is meant the weight of one substance compared with that of another. Water is taken as a standard for compari- son and its specific gravity is 1. Milk has an aver- age specific gravity of 1.032, being slightly heavier than water. A vessel holding 1,000 pounds of water would hold 1,032 pounds of milk. To find the weight of a gallon of milk multiply the weight of a standard gallon of water (8.35 lbs.) by the specific gravity of milk. Thus 8.35x1.032=8.62 pounds, the weight of a gallon of milk. Cream is lighter than milk because its chief con- stituent is butterfat, which has a specific gravity of only 0.9. Hence the richer the cream the lighter it is. Cream containing 20 per cent, butterfat has a specific gravity of about 1.01. Viscosity. This refers to the adhesiveness or stickiness of milk and cream. Milk is more viscous than water, and cream is still more viscous than milk. Viscosity is an important property to consider in connection with cream. In fresh, warm cream the viscosity is considerably less than in old, cold cream of the same richness. A fresh, warm cream may therefore appear to be lacking in richness when in reality it is lacking in viscosity. For the same rea- son fresh, warm cream is difficult to whip. Age and i6 PHYSICAL PROPERTIES OF MILK AND CREAM \J low temperature are about as important as the rich- ness of the cream in getting cream to Avhip satisfac- torily. When cream is heated to high temperatures, its viscosity is lessened even when subsequently cooled to a low temperature. This is due, in part at least, to the fact that the heating destroys the soluble lime, because the viscosity can be restored by adding lime in a soluble form. Lime will increase the viscosity of any cream, whether heated or not, and hence w411 make it appear richer than it actually is. For this reason a great deal of commercial cream has lime added to it. The quantity required is so small, how- ever, that it will escape detection, even by experts. Acidity. Fresh milk when tested by the usual alkaline methods, shows an acidity of about 0.14 per cent. When it reaches the consumer the acidity, as a rule, is close to 0.2 per cent. This is important to remember when cow's milk is substituted for breast milk in infant feeding. Breast milk shows no acidity, and for this reason when babies are fed on cow's milk the acidity is first neutralized by the addition of lime water. Absorbing Powers. Milk is peculiarly susceptible to odors, absorbing them as readily as a sponge ab- sorbs water. The same is true of cream. These products must, therefore, never be exposed to strong odors, not even those of vegetables, fruits, cakes, cheese and the like. Color. The color of milk varies with the breed of cattle and with the character of the feed. Holstein- Friesian milk has a white color, while that of Jer- seys is a light yellow. Guernsey milk has the rich- l8 MII.K AND MILK PRODUCTS IN THE HOME est color of any breed, being a deep yellow. When cattle feed on pasture or other green feed the color of the milk becomes more yellow. For these rea- sons the color of milk is not a reliable indication of richness. Carotin is the substance which gives milk its natural color. CHAPTER IV COMMON MILK BACTERIA What Bacteria Are. The term bacteria is applied to the smallest of living plants, which can be seen only under the highest powers of the microscope. Each of these plants is made up of a single cell. They are so small that 30,000 of them laid side by side will measure only about an inch. Their pres- ence is almost universal, being found in the air, water, soil, milk, decaying matter, etc. In everyday language bacteria are usually spoken of as germs. Figure 2 — Different shapes of bacteria (Lehmann & Neumann) Rapidity of Growth. Under favorable conditions bacteria grow with marvelous rapidity, some repro- ducing themselves a million times in twenty-four hours. The majority of bacteria require for best growth a warm, moist and nutritious medium such as milk, in which an exceedingly varied and active life is possible. 19 20 MILK AND MILK PRODUCTS IN THE HOME Most bacteria grow rapidly at temperatures be- tween 60° and 100° F. ; some are capable of multiply- ing at freezing temperatures, while others grow best at temperatures approximating 120° F. Beneficial and Injurious Bacteria. A great many species of bacteria are entirely harmless and some are decidedly beneficial. Other kinds produce unde- sirable flavors. Most dangerous and harmful of all are those bacteria which cause diseases like typhoid fever, diphtheria, scarlet fever, etc. Lactic Acid Bacteria — Beneficial. These are by far the most common of all the bacteria found in Figure 3 — Varieties of lactic acid bacteria (Conn) milk. The souring of milk and cream is due to these bacteria. They act upon the milk sugar, changing part of it into lactic acid, which gives milk its sour taste. When the acidity of milk reaches about 0.9 per cent., the lactic acid bacteria are either checked or killed by the acid they have produced, and the formation of acid ceases. In ordinary sour milk, about half of the milk sugar is left unchanged. Under cleanly conditions, the lactic acid type of bacteria always predominates in milk. "When, how- ever, milk is drawn under uncleanly conditions, the lactic acid organisms are often outnumbered by COMMON MILK BACTERIA 21 other kinds resulting in the production of tainted milk. The fine flavor of butter and that of many varie- ties of cheese, is due to the lactic acid bacteria. The tonic value of good sour milk is also due to these bacteria. In the famous experiments of Dr. Metch- inkoff, it was established that the lactic acid organ- isms exert favorable effects in the large intestine by destroying and combatting obnoxious kinds which are always present there. Because of their antag- onistic properties, the lactic acid bacteria act as a real safe-guard to milk, suppressing undesirable kinds capable of producing bad flavors, toxins, etc. Undesirable Bacteria. To this class belong the butyric acid bacteria, which are the chief cause of rancid butter; putrefactive bacteria, which decom- pose milk and cream ; bitter, slimy, gassy, toxic, and many other kinds of bacteria which need not be dis- cussed here. Most of the undesirable bacteria find their way into milk through particles of dust, manure, hair, flies, bits of hay, chaff, straw, etc. A single fly or hair may carry half a million bacteria; and while flies and hair may be strained out of milk, the bac- teria cannot, because of their extreme smallness. Occasionally milk becomes infected with disease producing bacteria. This class of bacteria will be discussed in another chapter. Spores. These are inactive bacteria which can re- sist high temperatures to a remarkable extent, some being able to endure a boiling temperature for many 22 MILK AND MILK PRODUCTS IN THK HOME minutes. Under favorable conditions, spores soon develop into active bacteria, in which condition they are readily destroyed by heat. Lactic acid bacteria do not produce spores, but putrefactive and other undesirable bacteria do. In heating milk, therefore, the lactic acid bacteria are destroyed first, and the spores left undestroyed will later grow and develop undesirable flavors in the milk. This is the reason why pasteurized milk (see page 37) will usually develop putrid odors with age, rather than sour as is the case with unheated milk. Numbers of Bacteria in Milk. Ordinary market milk literally teems with bacterial life, averaging about half a million bacteria per teaspoonful of milk. Such large numbers are not necessarily harmful to adults but they may seriously affect babies and young children. It is known that the prevalence of bowel trouble among children under two years of age is largely due to the consumption of milk con- taining large numbers of putrefactive and allied species of bacteria. CHAPTER V CARE OF MILK IN THE HOME No matter liow good the conditiou of the milk when delivered, if carelessly handled in the home it will keep sweet but a very short time. To keep milk and cream sweet and pure, they must be kept cold and clean. As soon as the milk is delivered, it should be put in a cool place — a clean refrigerator if possible. The vessels in which the milk and cream are kept must be sterile and covered. Vessels are not sterile unless they have been kept in boiling water for five minutes and then inverted upon a clean shelf with- out wiping. Importance of Low Temperature. Milk always contains bacteria no matter how cleanly the condi- tions under which it is produced. At ordinary tem- peratures these bacteria increase with marvelous ra- piditj^ ; at low temperatures their growth practically ceases. The effect of temperature on bacterial de- velopment is graphically shown in Figure 4 : 24 MILK AND MILK PRODUCTS IN THE) HOME At a temperature of 50° F. the bacteria multiplied five times; at 70° F. they multiplied seven hundred and fifty times. Roughly speaking, at 98° F. bacteria multiply at least one hundred times faster than at 70° F. At 32° F. bacterial development practically ceases. Milk or cream may be kept sweet a long time at 40° to 45° F. because the lactic acid bacteria prac- tically stop growing at these temperatures. But there are other classes of bacteria that can grow at these temperatures as evidenced by the production of undesirable flavors. Such flavors usually become noticeable after thirty-six hours. Air and Water Cooling. Milk should always be cooled to as low a temperature as possible by placing the receptacle containing it in cold water. Air cooling, such as would take place in a refrigerator, is very much slower than water cooling and for this reason milk and cream should always be cooled as much as possible with cold water before placing them in the refrigerator. The reason why air cools so much more slowly than water at the same temperature is the fact that air is a much poorer conductor of heat and cold than is water. Importance of Cleanliness. Nowhere does cleanli- ness count for so much as in the handling of milk. If a refrigerator is used, it should have a thorough cleaning at least once a week. Always see to it that the milk is put into clean, sterile vessels. Milk dishes may look perfectly clean but, unless they have been scalded or boiled, they may contain thousands of bacteria. carl: or ]\riLK in the home: 25 Especially important is it to give close attention to the baby's bottles. As soon as the baby has fin- ished his meal, the bottle and nipple should be rinsed with warm water (not hot), then washed in hot water containing some washing powder, like sal soda, and then scalded. Under no conditions should nip- ples be used which are joined to the feeding bottle by means of a rubber tube. Such tubes cannot be thoroughly cleaned. General Handling of Milk. All milk and cream should be pasteurized (see page 41) in the home, even if they have been previously pasteurized by the dealer. Modification of milk for baby feeding is also important. Both of these subjects are fully treated in separate chapters. The mistake is sometimes made in warming the entire tw^enty-four hours' allowance of milk for the baby and then using from this the amount required for a single feeding. Repeatedly w^arming and cool- ing milk will quickly spoil it. Only the amount re- quired for immediate use should be taken from the main supply and the latter should be kept cold until ready to use. Always take milk into the house as soon as de- livered, especially in hot weather. If this cannot be done, provide an insulated box into which the milk- man may put the bottle. On account of their great absorbent properties, milk and cream must be kept in covered vessels, especially w^hen. placed in the kitchen or cellar, or possibly in the refrigerator with fruits and vege- 26 MILK AND MILK PRODUCTS IN THE HOME tables. Aside from absorbing odors when exposed in these places, they will also take up bacteria which will shorten their keeping quality. Pour milk from one vessel to another as little as possible to avoid contamination ; and do not add new milk to old milk ; neither add warm milk to cold. The tops of the bottles should always be washed before removing any milk. They are more or less contaminated with dust during transportation and also become soiled from the hands. Always clean the bottles before returning them. CHAPTER VI MARKET CLASSES OF MILK In most country towns and villages only one grade of milk is sold. This is ordinary, raw milk contain- ing from 3 to 5 per cent, butterfat. In the larger cities, in addition to ordinary milk, other classes are sold such as certified, modified, evaporated, condensed, guaranteed, sanitary, pas- teurized, inspected, grades A, B and C, and dip or bulk milk. Certified Milk. Certified milk is the highest grade of market milk and is produced under conditions im- Figure 5 — Sanitary Dairy Barn 2^ 28 MILK AND MILK PRODUCTS IN THE HOME posed by medical milk commissions, which usually employ a veterinarian, a bacteriologist and a chemist to look after the production of the milk. It must come from healthy cows, be free from disease germs and preservatives, must have a known chemical com- position, and must be so produced and handled as to insure a minimum number of bacteria. If the pro- ducer has complied with all the requirements, he is furnished a certificate by the commission which per- mits him to use the ''certified" label on his products. The cows, milkers and premises are regularly in- spected, and the milk is regularly subjected to chem- ical and bacteriological tests. The number of bac- teria permitted by different commissions varies from 10,000 to 30,000 per cubic centimeter* of milk ; and the butterfat content ranges from about 3.5 to 4.5 per cent. The milk bottles are sealed and bear the date of bottling and the name of the commission. Delivery should be made within twenty-four hours after the milk is drawn and its temperature during this time should not exceed 45° F. The term ''certified milk" is registered in the United States patent office and its use is legally per- mitted only on milk approved by medical milk com- missions. Certified milk is now largely used for infants and invalids. There is, however, also a rapidly increas- ing use made of this milk by the better informed people who are not satisfied with the condition of average market milk. *A cubic centimeter (C. C.) is equal to about 25 drops. MARKET CLASSES OE MILK 29 Modified Milk. See page 44. Evaporated Milk. See page 54. Condensed Milk. See page 53. Guaranteed Milk. This is milk which is guaran- teed by the retailer to come up to certain require- ments, which vary in different localities. As a rule it contains a certain minimum of butterfat such as 4 per cent, or 5 per cent. To this may be added a guarantee that the milk is from non-tubercular cows. Sanitary Milk. Milk of this class is guaranteed as to certain high class sanitary conditions under which it is produced and handled. Pasteurized Milk. See page 37. Inspected Milk. This class of milk as a rule is produced under conditions requiring a high degree of cleanliness and cows which the tuberculin test has shown to be free from tuberculosis. These condi- tions are certified to by responsible inspectors. Grades A, B and C Milk. In New York state milk is graded according to its sanitary condition, the score card used being that shown on pages 97 and 98. Grade A requires a minimum score of 75, grade B 60, and grade C 40. Bulk or Dip Milk. The old method of hauling milk to the city in five, eight or ten gallon cans and removing each customer's allowance by means of a dipper or faucet, has been found so objectionable that the practice has been largely abandoned. The principal objections to this method are: (1) The ad- mission of dust and bacteria to the milk while meas- uring it; (2) the. use of unsterilized milk vessels by consumers; (3) exposure of the vessels to dust while ^o MII.K AND MILK PRODUCTS IN THi; HOME on the steps of the consumer; (4) the use of unclean vessels by milkmen in measuring each customer's share ; (5) lack of uniformity in the milk, especially if removed from the cans by means of a faucet, in which case the first drawn milk is likely to be low- est in fat content; and (6) the possibility of drivers tampering with the milk. JUDGING MILK AND CREAM In judging milk and cream a score card like the following is generally used : Item Bacteria Flavor and odor Visible dirt Buttertat Solids not fat.... Acidity Bottle and cap.. Total Perfect Score 35 25 10 10 10 5 5 100 Score Allowed Remarks Bacteria found per I cubic centimeter ) Flavor Odor Per cent, found. Per cent, found. Per cent, found. J Cap 1 Bottle EXPLANATION OF SCORE CARD Bacteria. The maximum number of bacteria per- missible per cubic centimeter for a perfect score on bacteria as a rule is 400. Numbers beyond this point will detract from the score until 200,000 is reached when the score is zero. Deductions from the perfect score are made uniform, being proportional to the bacteria count between 400 and 200,000. MARKET CU\SSES OF MILK 3I A bacteria count as low as 400 per c.c. is possible, ihough difficult to attain. By exercising proper cleanliness and thoroughly cooling milk, the major- ity of dairymen can keep the bacteria count beloAv lOjOOO per c.c. A low bacteria count is largely a matter of cleanliness and low temperature. Flavor and Odor. Flavor refers to taste and odor to the aroma detectable by the nose. It is impossible to describe a perfect flavor and odor. Anything in the least objectionable to the taste or smell will detract from the score. Under this head, weedy, stable, manure, bitter, rancid and unclean flavors or odors are most common. To obtain a perfect score for flavor and odor, perfect cleanliness must prevail, the milk must be kept free from odoriferous sur- roundings, and feeding must be done after milking, especially when silage or other odoriferous feeds are fed. Visible Dirt. Any sediment, however slight, in the bottom of the bottle will detract from the score. Most milk will show visible dirt if produced under un- cleanly conditions. Dust, particles of dirt, hair or particles of litter, and sometimes all of these, are noticeable in the bottom of bottled milk. The greatest factor in reducing dirt to a minimum is washing the cow's flanks and udder just previous to milking. The moist condition prevents the dis- lodgement of dirt. Another great aid in obtaining clean milk is the covered milk pail. Butterfat. To obtain a perfect score on butterfat, milk as a rule must contain not less than 4.0 per 32 MILK AND MILK PRODUCTS IN THE HOME cent. For each tenth below 4.0 per cent., 0.2 point is deducted from the perfect score till 3.5 per cent, is reached. A whole point is deducted for every tenth below 3.5 per cent. Milk with a butterfat content less than 2.7 per cent, or less than the legal local limit, is scored zero for butterfat. Cream is usually scored perfect for butterfat when its fat content is 20 per cent, or above. Solids Not Fat. Usually 8.7 per cent, or more is required for a perfect score on solids not fat. For each tenth per cent, below 8.7 one point is deducted. Milk containing less than 7.8 per cent, or less than the legal limit, is scored zero for solids not fat. Solids not fat are not considered in cream. Acidity. The limit of acidity for a perfect score is 0.2 per cent. When milk is thoroughly cooled there is little difficulty in keeping the acidity below this limit. Bottle and Cap. The following defects detract from the perfect score for bottle and cap : Partially filled bottle, tinted glass, leaky caps, improperly paraffined caps, unprotected caps and anything that in any way detracts from the appearance of the package. CHAPTER VII MILK-BORNE DISEASE BACTERIA Every consumer of milk should know that milk is frequently a carrier of bacteria which belong to the strictly disease-producing kind. Records show that numerous epidemics of typhoid fever, diph- theria, septic sore throat trouble and scarlet fever, have been caused by infected milk supplies. Per- haps one of the most menacing of all milk-borne disease bacteria is the tubercle bacillus. Fortunately in recent years great efforts have been made to safeguard milk supplies against these destructive disease-producing bacteria, and much has been accomplished in this direction. It is com- forting to know also that every consumer can make his milk supply absolutely safe against any disease bacteria by treating the milk as recommended in the next chapter on Pasteurization of Milk and Cream. Figure 6 — Tuberculosis bacilli (Lehmann & Neumann) 33 34 MILK AND MILK PRODUCTS IN THE HOME Tuberculosis. It is well known that one of the most common disease bacteria found in raw milk is the bovine (cow) tubercle bacillus. Examination of milk supplies throughout the country reveal the presence of this bacillus in milk to an alarming ex- tent. Frequently as many as 10 to 15 per cent, of the samples of milk examined show the presence of the tubercle organism. Indeed the prevalence of tuberculosis among cattle makes it positively unsafe to assume that the milk of any herd of cows is free from tubercle bacilli, unless the cows have been actually shown to be free from this disease by the tuberculin test. The question naturally arises: To what extent can tubercle bacilli from cows cause tuberculosis in man? The answer is graphically set forth in the fol- lowing table which presents the results of an ex- TABLE SHOWING PROPORTION OF TUBERCULOSIS OF HUMAN AND BOVINE ORIGIN IN PATIENTS EXAMINED Adults 16 Years Children 5 to 16 Children Under Diagnosis and Over Years. 5 Years. Human Bovine Human Bovine Human Bovine Pulmonary tuberculosis 778 3 14 - 35 1 Tuberculous adenitis. Sfi 1 33 7> 15 24 Abdominal tuberculosis 16 4 8 10 14 Generalized tuberculo- sis, alimentary origin 6 1 3 4 17 15 Generalized tuberculosis 23 — 5 1 74 7 Generalized tuberculosis including meninges alimentary origin — 1 _ 5 10 Generalized tuberculosis including meninges... 5 _ 10 _ 76 1 Tuberbular meningitis. . 1 — 3 — 28 4 Tuberculosis of bones and joints- 3? I 41 3 27 Tuberculosis of skin — 10 3 4 6 2 - MILK-BORNE DISEASE BACTERIA 35 haustive study of the subject by Park and Krum- weide and numerous foreign investigators. The table was prepared by Park and Krumweide of New York City. It not only shows different forms of tuberculosis in man, but also compares the number of cases due to human and bovine tubercle bacilli. The table shows that children are especially liable to infection with bovine tubercle bacilli. It is re- ported that of the total number of deaths of young children from tuberculosis, about 10 per cent, are from bovine infection. Epidemics Caused by Infected Milk. Over five hundred epidemics of common diseases caused by infected milk supplies are on record. The milk sup- Figure 7— Typhoid bacilli (Lehmann & Neumann) ply becomes infected with the disease germs of some person suffering from the disease. The infection may take place in many different ways which it is not necessary to discuss here. Typhoid infection is sometimes caused by persons known as '' typhoid carriers," who are not actually sick but heavily in- fected with the disease bacteria. In the following 36 MILK AND MILK PRODUCTS IN THE HOME) list of epidemics all infection is of human origin excepting septic sore throat trouble, which is now believed to be caused not only by milk infected with bacteria from human beings but also by cows suffer- ing from diseased udders. Septic Sore Throat. Dr. C. E. North reports the following epidemics: Boston, 1,043 cases caused by one raw milk supply Boston, 227 ' Chicago, 10,000 ' ' Baltimore, 602 Cortland- Homer, 669 Typhoid Fever. Trask reports 317 outbreaks of m hich the fol- lowing are typical cases : Glasgow, 500 cases caused by one raw milk supply Cologne, 270 " PortJervis, 59 Springfield, 182 Oakland, 262 '" Montclair, 107 Stamford, 307 Scarlet Fever. Trask reports 125 epidemics of which a few are given below: Buffalo, 57 cases caused by one raw milk supply Washington, 33 London, 284 Beverly, 6 Liverpool, 59 Mt. Vernon, 45 Boston, 195 Diphtheria. Trask reports 51 outbreaks, a few of which are as follows: aused by one raw milk supply Brookline, 12 cases c Los Angeles, 35 " VVellsville, 84 " Clifton, 36 •' Hyde Park, 69 " Warwick, 64 '• The difficulty of keeping disease-producing bac- teria out of milk is so great that occasionally even certified milk becomes infected with these organisms. CHAPTER VIII PASTEURIZATION OF MILK AND CREAM Ideal pasteurization consists in heating milk to 145° F. and keeping it at this temperature for 30 minutes, after which it is quickly cooled to 50° F. or below. This treatment w^ill kill all of the strictly disease producing bacteria as well as most of the common bacteria usually found in milk; in other words, pasteurization means killing bacteria. Necessity for Pasteurizing Milk. On an average every drop of ordinary milk contains about 20,000 bacteria. Some of these bacteria belong to the kind that irritate the intestines of babies and children, causing various forms of bowel trouble. No milk is entirely free from this class of bacteria, but the more cleanly the conditions under which the milk has been produced and handled the smaller the number of bad bacteria it will contain. In New York City during 1912, 3,392 babies under one year of age died from bowel trouble ; nine out of every ten of these were bottle fed. Other cities show similar records. It is the putrefactive and other filth bacteria contained in milk that are re- sponsible for the prevalence of bowel trouble and the high mortality among bottle fed babies and young children. It is estimated that in the large cities about one- lialf of the deaths of infants under one year of age result from bowel troubles and that four-fifths of these have been bottle-fed. 37 38 MILK AND MII.K PRODUCTS IN THE HOME It is a matter of common knowledge that the sum- mer following the weaning of breast-fed babies, is usually one of more or less danger to the child. Many mothers expect ''summer complaint" at this time as a perfectly natural thing, little realizing that bowel trouble is commonly due to the irritating effect of bacteria contained in the child's milk. The frequent presence in milk of infectious dis- ease bacteria as discussed in the preceding chapter, furnishes additional reasons for pasteurizing milk. These bacteria are especially to be feared because they not only affect babies and children but are equally dangerous to grown people. So difficult is it to safeguard milk completely against these deadly organisms that even certified milk, in several in- stances, has been known to contain them. Since all serious danger from bacteria is removed by the pasteurizing process, it certainly seems noth- ing less than folly not to pasteurize milk, especially that produced and handled under prevailing condi- tions. What has been said here in reference to the need of pasteurizing milk applies with equal force to cream. Pasteurization by Milk Dealers. To eliminate as far as possible the danger of disease resulting from the consumption of raw milk, great efforts have been made in recent years by public health officials to have milk pasteurized before it is delivered to the consumer. In a number of large cities pasteurization of the ordinary grades of milk has been made com- PASTEURIZATION OF MILK AND CRE;AM 39 pulsory. Very notable improvement has followed this practice. In New York City, for example, where an average of 17,000 babies were fed daily on pas- tenrized milk during a period of three years, the death rate per 1,000 births decreased from 125 to 94. Similar results have been secured in many other places. Perhaps the most significant results follow- ing the pasteurization of milk are those secured at the Infant Asylum at Randall's Island, New York City. The death rate among the babies in this insti- tution during 1895 to 1897 inclusive averaged from 39 to 44 per cent. At this time Mr. Straus secured the establishment of a complete pasteurizing i^lant on the island and the first year following the pas- teurization of the milk the death rate dropped to less than 20 per cent., or less than half what it was before the milk was pasteurized. Advantages of Pasteurizing in the Home. Unfor- tunately much milk has been poorly pasteurized in the past, and there is undoubtedly much inefficiently pasteurized milk sold at the present time. It occa- sionally happens, too, that efficiently pasteurized milk is put into unsterilized bottles, which destroys the value of the pasteurizing process. Milk may also become infected in the interval between pasteurizing and bottling. An instance is cited by Dr. C. E. North in which 85 cases of typhoid fever were traced to milk which had become infected through a "typhoid carrier" whose business it was to cap the bottles. Another instance is on record where a driver, convalescing from scarlet fever, left a trail of the disease along his route. The driver had a running 40 MII,K AND MILK PRODUCTS IN THi; HOME: sore on his finger and in taking hold of the tops of the bottles infected them with the disease germs. It is largely for these reasons that the author for years has recommended pasteurizing the milk in the home. Moreover, when the milk is pasteurized in the home, there are advantages in buying raw rather than pasteurized milk. Under ordinary conditions, for example, raw milk will not keep long, and for this reason must be sold shortly after it is produced. Pasteurized milk, on the other hand, is often sold when several days old. In this connection it is to be remembered that old pasteurized milk, especially when kept at rather high temperatures, may be dan- gerous to babies and young children. Under such conditions the bacterial spores, which are not de- stroyed by the pasteurizing process, develop into enormous numbers and may cause very serious bowel disturbances. For this reason when j^asteurized milk is purchased, it is desirable to repasteurize it in the home. Another advantage in buying raw milk is the fact that the conditions under which milk has been Figure 8— Double boiler (Cooker) PASTKURIZATIOX OF :MILK AND CREAM 4 1 produced can ahvays be told better in raw than in pasteurized milk. Home Process of Pasteurization. A common two-quart double boiler, like that shown in Figure 8, furnishes the best means of pasteurizing milk and cream in the home. Put a few inches of water in the outer vessel ; then rinse the inner one with boil- ing water and pour the quart of milk into it. Now heat the milk to 145° F. and keep it at this tempera- Figure 9 — Dairy thermcineter ture for thirty minutes using a dairy thermometer to note the temperature. The thermometer should not be removed from the milk until the heating is completed. It is also neces- sary to stir the milk frequently during the heating to prevent a "skin" forming at the surface. If a spoon is used to stir the milk, this should also be kept in the milk until the pasteurizing is completed. As soon as the heating is finished, the milk should be promptly cooled to as near 45° F. as possible. The lower the temperature the better the milk will keep. During the cooling the milk is kept in the same vessel in Avhich it was heated. By changing the water several times in the outer vessel the tem- perature of the milk is quickly reduced. After cool- ing, the milk may be put into sterilized bottles or it may be kept in the boiler, care being taken to keep the receptacles well covered. The reason why milk should be kept near 145° F. during pasteurization is the fact that, at tempera- 42 MILK AND MILK PRODUCTS IN THE HOME tiires somewhat lower than this, the bacteria will not be destroyed, while at higher temperatures undesir- able changes take place in the milk. An exposure of a few minutes at 165° F. will affect the taste of milk, begin to curdle the albumen, and will also affect the enzymes present in milk. It is important, therefore, that milk intended for baby feeding be kept at 145° F. as closely as possible during the pasteurizing process. Milk intended for adults need not be watched so carefully, and no particular harm will result from heating such milk to 165° F. The changes taking place at this temperature, however, would impair its digestibility too much for baby feeding. In pasteurizing milk, the higher the temperature the shorter the time required to kill the bacteria. Thus, a temperature of 160° F. maintained for ten minutes will prove quite as effective in destroying bacteria as 145° maintained for thirty minutes. There are other methods employed in pasteurizing milk in the home such as pasteurizing in the original bottle or transferring the milk to smaller bottles for baby feeding ; and good results may be obtained with these methods. However, the author's experi- ence in pasteurizing milk in the home during the last fifteen years has convinced him that for the average family the double boiler will give the best results. Inefficient Pasteurization. Milk that has been un- derheated is more dangerous than that which has not been heated at all. The reason for this is that PASTEURIZATION OF MILK AND CRE:AM 43 inadequate heat in pasteurizing may destroy the lactic acid bacteria (Avhich are easily killed) and by so doing actually better the conditions for the growth of the more resistant and obnoxious kinds. Lactic acid organisms are antagonistic to other classes of bacteria and are therefore a real safe- guard to milk. This makes it plain that unless milk is pasteurized at a temperature which will destroy the pathogenic and non-acid bacteria as well as the acid bacteria, it is far better not to heat it at all. Digestibility of Pasteurized Milk. The success which has attended the feeding of pasteurized milk to thousands of babies is convincing proof that the digestibility of milk is not impaired by the pasteur- izing process. The remarkable results obtained by Straus in his charitable dispensations of pasteurized milk to thousands of babies in New York City early proved the high value of this class of milk. Later in the City of New York where, during three years, an average of 17,000 babies were daily fed on pasteur- ized milk, the digestibility and food value were found equal to those of raw milk. In all this work no trouble from rickets or scurvy was encountered. It is more than probable that the earlier objec- tions to pasteurized milk for baby feeding were due to faulty methods of pasteurization. It is gen- erally admitted, however, that for some babies pas- teurized milk is slightly more constipating than raw milk. This objection is insignificant when compared with the advantages gained by the pasteurizing process. CHAPTER IX MODIFIED MILK Modified milk is cow's milk whose composition has been changed to approximate that of breast milk. It is used as a substitute for breast milk in feeding infants and babies who, for one reason or another, have been deprived of their mother's milk. That there is need of modifying cow's milk for baby feeding will be conceded when the differences between it and breast milk are fully understood. Breast and Cow's Milk Compared. The average composition of breast and cow's milk is shown in the following table : Water Butter- fat Casein Albu- men Milk Sugar Ash Cow's milk. . Breast milk . 87.2 88.2 3.8 3.4 % 2.8 0.6 0.6 0.5 4.9 7.1 0.7 0.2 The chief difference between the two milks, it will be noted, is in the casein content, which is nearly five times as great in cow's milk as in breast milk. Furthermore, the casein of cow's milk has an acid reaction while that of breast milk is practically neutral. The acid condition of the casein, together with the lactic acid present in cow's milk, causes the latter to clot when taken into the stomach. The clotting of milk has little significance with adults or children with strong digestion, but there are 44 MODIFIED MILK 45 thousands of babies who cannot digest these clots and hence suffer from colic and other discomforts. To adapt cow's milk to baby feeding, therefore, requires that it be changed, not only to prevent the formation of clots in the stomach but also to rid it of the excess of casein wiiich causes an unneces- sary tax upon the digestive system. This is accom- plished by diluting milk with water. Figure 10 — Apparatus and materials used in modifying milk. Left to right is quart of milk, cream dipper, pint of milk, viscogen, milk sugar, oat water, thermometer and double boiler Amount of Water to Add. The amount of water to be added to milk must be gauged largely by the total proteids in milk, which are about three times greater in cow's than in breast milk. It must also partly be determined by the age of the child. Infants and children, like young animals, require changed rations with advancing age. Thus in some of the laboratories where milk is modified on a large scale, the percentages vary as follows : 46 MILK AND MILK PRODUCTS IN THE HOME Age of Child Butterfat Sugar Protein One week Per Cent. 2.00 3.00 Per Cent. 4.50 6.00 Per Cent. 0.75 Four weeks 1.00 Seven weeks 3.50 6.50 1.25 Fourteen weeks 3.50 6.50 1.25 Twenty weeks Thirty weeks 3.75 4.00 6.50 6.50 1.50 L75 Where naturally rich milk is used or milk that has been enriched by the addition of cream, one part of milk to two and a half to three parts of water is about right for infants under one week old. After this the water is gradually reduced so that at the end of the sixth week water and milk are used in practically equal proportions. Beginning with the twentieth week, one part of water to two of milk will be about right. At the age of one year the child may be given plain, unchanged cow's milk. Adding Milk Sugar. Cow's milk is naturally de- ficient in milk sugar when used for baby feeding. This deficiency is materially increased by the water added to reduce the proteids. Hence the necessity of adding commercial milk sugar (lactose). Under normal conditions about an ounce must be added daily to the child's ration. Milk sugar is preferable to ordinary (cane) sugar because it is more digestible. In case of severe con- stipation, maltose (malt sugar) may be used to ad- vantage in place of milk sugar because it is more laxative. MODIFIED MILK 47 Reducing- Acidity. Fresh cow's milk shoAvs an acidity of about 0.14 per cent. ; this amount is us- ually increased to almost 0.2 per cent, by the time it reaches the consumer. Breast milk is practically neutral, that is, shows no acidity. To reduce the acidity of cow's milk, lime water is added. This is best used in the form of viscogen, Avhich is sucrate of lime (see page 67). One table- spoonful of viscogen to a quart of modified milk is usually sufficient. This amount is equivalent to about ten tablespoonfuls of ordinary (U. S. P.) lime water such as is commonly bought in drug stores. Viscogen is recommended here because of its cheapness. Its cost is less than one-twentieth that of commercial lime water. Viscogen cannot be bought but must be prepared in the home as directed on page 67. Oatmeal Water. After the child is a month old it will be found advantageous to use oatmeal water in place of plain water for diluting the milk. The oat- meal water is prepared by adding a tablespoonful of rolled oats to a pint of water and boiling the mixture for at least thirty minutes. Then strain through several thicknesses of cheese cloth. The use of oatmeal water in place of plain water in diluting milk is especially recommended for babies troubled with constipation. It is laxative and also contributes valuable food material. The strength of the oatmeal water may be doubled after the child is four or five months old. Barley flour and similar materials are often used in place of rolled oats, but these are too expensive 48 MILK AND MILK PRODUCTS IN THE HOME for the average home and have, in most cases, no particular advantage over oatmeal water for nor- mal babies. Adding Cream. Where average market milk is used, a small amount of cream is necessary in modi- fying milk. An extra pint of milk is generally pur- chased from which to obtain this cream. The milk is allowed to stand undisturbed for at least an hour and then about two ounces of cream are removed by means of a conical dipper like that shown in Figure 10. This amount of cream supplies the deficiency in butterfat. Summary. The following table presents a sum- mary of approximate proportions of materials used in modifying milk for babies at different ages : Table showing daily allowance of Feed at Different Ages Age or Baby Average Market Milk Cream from Top of Extra Pint of Milk Water Oatmeal Water Viscogen (Home- made L i m e- water) Milk Sugar Ounces Ounces Ounces Ounces Ounces Ounces First Week 4 1 12 i Second Week... 5 1* 10 I Third Week . . . 7 H 10 Fourth Week . . . S 2 10 J Second Month . . 10 2 12 1 Third Month ... 12 2 12 I Fourth Month .. 16 2 12 i Fifth Month . . . 18 2 12 Sixth Month . . . 20 2 10 J Seventh Month. . 22 2 10 J Eighth Month .. 24 2 8 Ninth Month .... 26 1 8 I Tenth Month.... 28 1 5 i Eleventh Month 30 1 5 h Twelfth Month.. 32 MODIFIED MILK 49 In case common drug store lime water is used in place of viscogen, the amount must be about ten times as great. In other words, one-fifth ounce of viscogen contains as much lime, and therefore has the same effect, as two ounces of common lime water. Requirements Vary. All babies cannot use the same ration. Some require more food and some less than that given in the preceding table. The propor- tion of materials used also varies. Some babies re- quire more butterfat, others may be benefited by more milk sugar. Others again may require less of these materials. The extent of dilution with water may be advantageously decreased in some cases and increased in others. Lime has a constipating tend- ency and may have to be reduced in some cases. The baby must be closely watched to learn its re- quirements. How to Feed. During the first five months, babies should be fed about every three hours during the day and once during the night. After the fifth month, the interval between feedings may be in- creased to three and one-half and four hours and the night feeding omitted. The allowance at a feeding averages about two ounces the first week, three ounces the second and third weeks, three and one-half to four ounces from the third to tenth week. After this time the allow- ance is gradually increased so that at the ninth month about eight ounces are used at a feeding. The manner of feeding discussed here may have to be modified somewhat according as the child is weak or strong. 50 MILK AND MILK PRODUCTS IN THE HOME The Value of Whey. In ordinary baby feeding when the first signs of digestive disturbances appear 4mf 1 Figure 11 — From right to left is quart of milk, rennet tablets, whey from quart of milk, curd from quart of milk it is important to reduce the quantity or the quality of the milk, or both, to relieve the strain on the digestive system. In cases, however, where babies are suffering from severe attacks of indigestion or other sickness, they are usually materially benefited by temporarily substituting whey for the modified milk. Whey is largely composed of milk sugar and albumen, the two soluble constituents of milk. It is a light food, very easily digested. For method of preparing whey see page 63. Herd Milk Preferred. Herd milk on account of its greater uniformity, is always preferred to milk from single cows. Not only does the quality of milk from individual cows fluctuate greatly from day to MODIFIED MILK 5 1 day, but it also increases in richness with the ad- vance of the period of lactation. In herd milk these daily variations are less the larger the herd. More- over, dairymen retailing milk from herds, have cows freshen at different periods so as to maintain a uni- form supply of milk throughout the year, thus minimizing the effects from the advancing period of lactation. Goat's Milk. Milk from single goats has the same objections as that from single cows. Such milk must be modified the same as cow's milk. Indeed, in spite of the claims made for goat's milk, there is no better substitute for breast milk than cow's milk. Other Substitutes. AVhere cow's milk cannot be obtained, sweetened condensed and evaporated milk j may be used. But there are various objections to this class of milk for which the reader is referred to chapter X. Various proprietary foods are in extensive use, but according to the eminent baby feeding specialist, Dr. L. E. Holt, these are less satisfactory than any of the other substitutes for breast milk that have been considered. How to Keep Modified MUk. As soon as the milk is pasteurized, it should be put into sterile bottles. Some prefer to put the milk directly into the nurs- ing bottles, each holding enough milk for one feed. But the simplest method is to put the milk into two pint bottles and then pour the milk from these into the nursing bottle as required. Small nursing bot- tles are difficult to clean and for this reason the fewer in use the better. 52 MILK AND MILK PRODUCTS IN THE HOME In all cases the milk should be covered and stored at a low temperature in a clean place. Warming the Milk. Without exception the milk should be warmed before feeding. This is best ac- complished by surrounding the nursing bottle con- taining the baby's feed with warm water. Frequently where haste is made to warm the milk quickly, the bottle is surrounded with hot water (150° F. or above). This, however, has the same bad effect as pasteurizing milk at these temperatures. The milk which comes in contact with the glass has practically the same temperature as the surrounding water and this portion may be entirely overheated when the mixture is only moderately warm. All milk should be fed at blood temperature, or 98° F. CHAPTER X CONDENSED AND EVAPORATED MILKS Sweetened condensed and evaporated milks are made as a rule from a good quality of cow's milk. The bulk of this class of milk is retailed in her- metically sealed tin cans holding six or more ounces of milk. The greatest field of usefulness for milk of this kind is in sections where it is difficult to obtain fresh milk. Sweetened Condensed Milk. In the manufacture of this class of milk, about two and one-half to two and three-fourths pounds of fresh milk are required to make one pound of condensed milk. The con- densation is accomplished in vacuo, that is, under reduced atmospheric pressure. In this way the natural boiling temperature is reduced to a point where the moisture can be driven off at a relatively low temperature. It is only at the beginning of the condensing process that the milk is exposed, for a short time, to a high temperature. This results in the destruction of most of the bacteria present in the milk. It also renders insoluble part of the min- eral matter, especially the lime. Condensed milk is not sterile, however, its preser- vation being effected by the addition of large quanti- ties of cane sugar (sucrose). About 40 per cent, of condensed milk is cane sugar. The syrupy condition produced by the sugar stops ordinary bacterial growth. 53 54 MILK AND MILK PRODUCTS IN THE HOME The addition of large quantities of sugar reduces the digestibility of the milk because cane sugar is not as easily digested as the constituents of fresh milk. The cane sugar also unbalances condensed milk as a food, making it rich in carbohydrates and relatively poor in proteids. In this connection it will be remembered that fresh cow's milk is a well balanced food. Sweetened condensed milk has an average com- position as follows: Water 26.5 per cent. Butterf at 9.0 per cent. Proteids 8.5 per cent. Milk sugar 13.3 per cent. Cane sugar 40.9 per cent. Ash 1.8 per cent. 100.0 Evaporated Milk. This is unsweetened condensed milk, preserved by sterilization under steam pres- sure. From two to two and one-half pounds of fresh milk are required to make one pound of evaporated milk. The high temperature required to render the milk sterile produces changes in the milk constituents. Part of the milk sugar is oxidized or caramelized, giving the milk a light brown color. Most of the al- bumen is rendered insoluble. Usually most of the casein is precipitated but the precipitate is again broken up by vigorous shaking in the process of manufacture. A large portion of the ash is rendered insoluble, the lime often appearing in the bottom of the can in the form of insoluble granules. The CONDENSED AND EVAPORATED MILKS 55 enzymes or digestive ferments are also destroyed by the sterilizing process. The average composition of evaporated milk is as follows : Water 73.0 per cent. Butterf at 8.3 per cent. Proteids 7.5 per cent. Milk sugar 9.7 per cent. Ash 1.5 per cent. CHAPTER XI SOUR MILK In discussing the use of sour milk, it should be remembered that the souring is due to the lactic acid bacteria which are always present in milk. These bacteria, besides souring milk, antagonize most of the common milk bacteria, especially the putrefac- tive kinds. They are also known to be antagonistic to many disease producing bacteria. Sour milk is, therefore, commonly looked upon as having anti- septic properties, and, because of this, it is exten- sively recommended as a tonic or health drink. It is now sold to the trade under various names such as buttermilk, cultured milk, Bulgara, Pokolac, Bacillac, Fermillac, Vitalac, Yoghurt, Zoulac, etc. Some of these preparations are made from partially skimmed milk. Medical Value. It was Dr. Metchnikoff of the Pasteur Institute who first proclaimed the full vir- tues of sour milk, especially that soured with the Bacillus Bulgaricus, which is the name applied to a species of lactic acid bacteria indigenous to Bul- garia where Metchnikoff found people to live to an unusually old age. Investigation proved to him that the regular indulgence in a drink, Yoghurt, con- taining this bacillus, was largely responsible for the good health and longevity of Bulgarians. Metchni- koff demonstrated that the Bulgarian and other lactic acid bacteria are antagonistic to putrefactive S6 SOUR MILK 57 and allied organisms and that, by virtue of this, when taken into the system, will check putrefaction in the intestines and thus prevent the formation of toxic substances, which give rise to a retinue of in- testinal and bodily disorders. The antiseptic value of sour milk is believed by Metchnikoff to be the means of prolonging life to a very appreciable ex- tent. Dr. North's report on the antiseptic value of lactic acid bacteria in the treatment of certain dis- eases, says that these bacteria as a w^ash or spray on inflamed surfaces or cavities often diminish the discharge upon such surfaces or cavities; that they often diminish odors caused by putrefac- tion ; and that they sometimes appear to check both acute and chronic inflammations caused by infec- tions. Undoubtedly in many cases where favorable re- sults have been obtained from the use of sour milk, the acid itself has been of much value. Indeed, it is well known that the acid of sour milk has very beneflcial effects in certain stomach disturbances. Sour milk is frequently fed to babies suffering from chronic or acute indigestion. As to the antiseptic value of sour milk, it has been shown experimentally that dangerous disease bacteria, like those causing typhoid fever, are killed as a rule in about four days when placed in sour milk. Natural Buttermilk. Most butter is made from sour cream, and the buttermilk, which is a by- 58 MILK AND MILK PRODUCTS IN THE) HOME product of butter manufacture, is therefore naturally sour. When butter is made from clean flavored sour cream, the buttermilk has practically the same tonic or medicinal value as other commercial forms of sour milk. As a rule, however, natural butter- milk is inferior to these, both in flavor and in the quantity of desirable bacteria it contains. The lactic acid bacteria die off very rapidly in sour milk, and, since natural buttermilk is usually older when sold than other commercial forms, it naturally con- tains fewer of these bacteria. Ordinary Sour Milk and Skimmilk. It is well known that good, natural buttermilk has a peculiar flavor which is highly relished by most people and which is different from that of ordinary sour milk or sour skimmilk. When, however, or- dinary sour curdled milk or skimmilk is churned or agitated the same as is cream in making butter, it will assume the characteristic flavor of natural buttermilk. The churning process incorporates air and thoroughly breaks up the curd clots, resulting in a smooth, thick liquid which cannot be distin- guished from ordinary good buttermilk. A reasonably good buttermilk or sour milk for drinking may, therefore, be made by allowing milk or skimmilk to curdle thoroughly and then breaking up the curd by vigorous agitation. The more butter- fat the milk contains, the greater the palatability and food value of the sour milk made from it. Ideal Sour Milk for Drinking. As has already been pointed out, ordinary milk contains many kinds of bacteria, — good, bad and indifferent. To get the SOUR MILK 59 best sour milk, therefore, it is necessary to destroy the bacteria in the milk by pasteurization and then to add lactic acid bacteria in pure form in which they are generally spoken of as pure cultures of lactic acid bacteria. These cultures cost about 50 cents per bottle and can be made to last about a month. Method of Using^ Cultures of Lactic Acid Bac- teria. Pasteurize a quart of milk at about 165° F. Figure 12 — Cultures of lactic acid bacteria for thirty minutes. Cool to about 80° F. Then add bottle of lactic acid bacteria, stir well and set aside at room temperature to sour. When thor- oughly curdled, which usually requires twenty-four hours, pasteurize another quart of milk, cool to 80° F. as before, and then add a few tablespoonfuls of the curdled milk and allow to sour at room tempera- ture. In fact the second bottle of sour milk is made just like the first except that, in place of the bottle of culture, a few tablespoonfuls of the curdled milk are added to sour it. A third bottle is prepared 6o MILK AND MILK PRODUCTS IN THE HOME from the second, and so on, as long as the flavor remains good. When bad flavors appear, a new bottle of culture must be purchased. It will be noted from this that the process of propagating lac- tic acid cultures is somewhat similar to propagating yeast for bread making. As soon as the newly pasteurized milk has been inoculated with the curdled milk, the balance of the curdled milk is then vigorously shaken in the bottle until the curd is sufficiently broken up to make it suitable for drinking. The best possible sour milk obtainable is prepared in this way, and the richer the milk the more palatable it will naturally be. By adding a bottle of sour milk prepared in this way to cream used for buttermaking or to skimmilk for cottage cheese making, the flavor of the butter and cheese will be greatly improved. Advantages of Milk Soured in the Home. There are several important advantages in preparing sour milk in the home in the manner described above. In the first place the sour milk can be used in prime condition, which is immediately after it has curdled. At this time it has the mildest degree of acidity and also contains the largest number of lactic acid bac- teria. In this connection it will be remembered that soon after curdling, the lactic acid bacteria die off very rapidly, and the older the sour milk the fewer of these bacteria it will contain. The highest tonic or medicinal value of sour milk is therefore obtained when used immediately after it has curdled. If kept SOUR MILK 6l at low temperatures (below 50^ F.) sonr milk may be kept in good condition for a considerable time. Preparing sour milk in the home also has all the advantages described under ''Advantages of Pas- teurizing in the Home," page 39. Value of Cleanliness. To obtain the best sour milk and to assist in propagating the lactic acid bacteria in pure form, requires that all bottles and vessels with which the milk comes in contact be thoroughly sterilized with scalding or boiling water before using. Cleanliness and thorough pasteurization are the secrets in obtaining fine flavored sour milk. Buttermilk Tablets. Various kinds of buttermilk tablets are found on the market which consist of small quantities of cultures of lactic acid bacteria in compressed form. These act much more slowly than the cultures obtained in bottles previously described. Otherwise they act in the same manner. It is in- tended that each bottle of sour milk be prepared with a new tablet. CHAPTER XII WHEY, SKIMMILK AND COTTAGE CHEESE WHEY Whey is the by-product of the manufacture of cheese. It is the liquid part of milk obtained by curdling the milk with rennet extract and then breaking up the curd and applying heat for a short time. Composition. Fresh whey made from sweet milk has the following average composition: Water 92.84 per cent. Milk sugar 5.00 per cent. Albumen 0.70 per cent. Casein 0.20 per cent. Butterf at 0.40 per cent. Lactic acid 0.16 per cent. Ash 0.70 per cent. 100.00 Food Value. From the composition it is seen that whey contains about the same percentage of milk sugar, albumen and ash as milk, but the butterfat and casein have been largely removed. Whey has approximately half the food value of milk. With most of the insoluble casein removed, whey consti- tutes a light food, extremely easy of digestion. It is, therefore, especially valuable as a substitute for milk in feeding babies suffering from indigestion and during general illness. It is equally valuable for children and adults suffering from digestive dis- turbances. 62 WHEY, SKI MM ILK AND COTTAGE CHEESE 63 Preparation of Whey. Whey is prepared as fol- lows : Heat a quart of milk to about 90° F. ; add one junket tablet, dissolved in cold water, or about five drops of rennet extract or rennin; mix vigorously for a moment and then let stand quietly to curdle. When well curdled, slice the curd into pieces about the size of a hickory nut and then pasteurize the same as milk, stirring the curd during first five minutes of heating and occasionally thereafter. Strain while hot through several thicknesses of cheese cloth, and bottle. Keep the whey cold and use it unmodified. Making Rich Whey. In making whey the chief purpose is to get rid of the casein, which is hardest to digest. But in the ordinary process described above, most of the butterfat is incidently eliminated with the casein. More of the butterfat can be retained in the whey by mixing the curdling agent (rennet extract) with the milk while cold (45° to 55° F.) and keeping the milk cold a number of hours. The rennet extract scarcely acts in cold milk and the cream is therefore free to rise and will continue rising as long as the milk is kept cold. If the milk is warmed later to the usual curdling temperature without disturbing it, practically all of the cream which has risen on it will pass into the whey. As much as one-half of the original butterfat in the milk can be worked into the whey by keeping the milk cold several hours. SKIMMILK This is milk from which the cream has been re- moved. It is essentially the milk less the butterfat 64 MILK AND MILK PRODUCTS IN THE HOME as will be seen from the following average composi tion : Water 90.50 per cent. Butterf at 0.10 per cent. Milk sugar 4.95 per cent. Casein 3.15 per cent. Albumen 0.52 per cent. Ash 0.78 per cent. 100.00 From the composition it is seen that skimmilk has essentially the same proteid and mineral content a^ milk, and therefore has practically the same muscle and bone building value. Its total food value, how- ever, is only about one-half that of milk. COTTAGE CHEESE Food Value. Cottage cheese is made from skim- milk and consists chiefly of casein and water. It is therefore a proteid food like beef steak, with which it compares favorably in food value. When moder- ately soft and moist it ranks as one of the most digestible of foods. The presence of the acid and the large number of lactic acid bacteria in fresh cottage cheese also gives it tonic value similar to that of sour milk. Its composition is as follows : Water 73.0 per cent. Proteids 19.0 per cent. Sugar and lactic acid 5.5 per cent. Ash 2.5 per cent. lOOOO" Home Manufacture. Cottage cheese is easily made as follows : Allow skimmilk to sour at room tem- WHEY, SKI MM ILK AND COTTAGE CHEESE 65 perature (about 75° F.), and when firmly curdled, heat to about 90° F. and pour the curd into a cheese cloth bag and hang this up to drain. The draining requires a number of hours and should be continued until all free moisture has escaped. When suf- ficiently drained add a little salt and cream to im- prove the flavor. The finest flavored cottage cheese is obtained by adding to the skimmilk a small amount of milk soured Avith cultures of lactic acid bacteria. See page 59. Defects in Cottage Cheese. Commercial cottage cheese often has a dry, rubbery texture, or it may be bitter and sour. The former condition is caused by employing too high a temperature in making the cheese, the latter by too much moisture and age. CHAPTER XIII CREAM "When milk remains undisturbed the butterfat globules, being light, begin to rise and soon there will be a rich layer over the milk, which is cream. The longer milk stands, within certain limits, the more cream will form at the surface. The limit of creaming is generally reached in twenty-four hours. Practically all cream sold at the present time is separated instantly from milk by centrifugal force, Avhicli is generated in a "cream separator." By means of an adjustment, cream of any richness can be produced with this method of creaming. Composition. Cream contains all the constituents found in milk, with the butterfat greatly predom- inating. The following is the composition of a fairly good quality of market cream: Water 66.41 per cent. Butterfat 25.72 per cent. Casein and albumen 3.70 per cent. Milk sugar 3.54 per cent. Ash 0.63 per cent. 100.00 Cream of course is valued for its butterfat, and the price asked for it varies almost directly in pro- portion to its richness in this constituent. Thus cream containing 40 per cent, butterfat sells for practically double the price of 20 per cent, cream. Market cream varies in richness from 18 to 50 per cent., the great bulk of it containing about 20 per cent, butterfat. 66 CREAM 67 Food Value. Cream is rarely purchased for its food value except when prescribed by a physician for patients requiring a rich and very digestible diet. Being rich in butterfat, it is naturally a very nutritious, but one sided, food. It is rich in heat and energy-forming material and relatively poor in muscle forming elements. Cream is chiefly used as a relish and in this re- spect undoubtedly stands without a rival. Pasteurizing Cream. Cream is pasteurized in pre- cisely the same manner as milk. Moreover, there exists the same necessity for this treatment because cream contains the same kinds of bacteria as the milk from which it has been obtained and in even larger numbers. One effect of pasteurizing cream is to reduce its body or viscosity; this, however, is largely re- stored by holding the cream at a low temperature a number of hours after pasteurization. A quick method of restoring the viscosity of pasteurized cream is to treat it with a small quantity of soluble lime. This not only restores the original body or thickness of the cream, but increases it to such an extent that a great deal of cream, both pasteurized and unpasteurized, is fraudulently so treated. It leads the consumer to believe that his cream is richer than it actually is. Viscogen. The soluble lime which is added to cream is known as viscogen. It consists of lime dis- solved in a strong solution of sugar. The method of preparation is as follows : Slake one part of good 68 MILK AND MILK PRODUCTS IN THE HOME; quick lime in three parts of water; add this to two and one-half parts of sugar dissolved in five parts Figure 13 — Materials for viscog:en. At the left is sugar and water in which it is to be dissolved; at the right is lime and water in which it is to be dissolved of water. Shake the mixture at intervals for about an hour and then allow to stand quietly for twenty- four hours. The clear liquid which has formed is viscogen. This should be carefully bottled, either with the sediment or without. The sediment con- sists of undissolved lime. Viscogen will keep for weeks if kept well stoppered in a dark, cold place. Figure 14 — From left to right is sugar solution, slaked lime, viscogen. Note sediment of undissolved lime in bottle of viscogen at right CREAM 69 The purpose of the sugar is to increase the solubil- ity of the lime. Viscogen is about ten times as strong as ordinary lime water prepared without sugar. Aside from its use in thickening thin cream and in assisting in the whipping of either pasteurized or unpasteurized cream, viscogen is very useful also in modifying milk. See page 47. Visco-Cream. The amount of viscogen required to restore the original consistency of pasteurized cream is about one part to one hundred and fifty parts of cream, which is equivalent to two-thirds teaspoon- ful of viscogen to one pint of cream. Cream that has been so treated and sold to the public must be labeled visco-cream. But owing to the difficulty of detecting the small quantity of lime added, a great deal of treated cream is sold as untreated cream. Homogenized Cream. As previously stated, the addition of lime water (viscogen) to cream materially increases its body, making it look much richer than it actually is. Another method of increasing the body of cream is to force it under high pressure through a special machine which breaks up the fat globules into very minute particles. This process is known as homogenizing. A naturally poor qual- ity of cream can be made to look fairly rich by sub- jecting it to the homogenizing process. A great deal of market cream is homogenized at the pres- ent time. Whipping Cream. To get cream to whip satis- factorily several important conditions are necessary : 70 MILK AND MILK PRODUCTS IN THE HOME The cream must be fairly rich and slightly acid; it must have been kept cold at least two hours previous to whipping and must have a temperature not ex- ceeding 60° F. during whipping. The richer the cream and the lower the temperature the better it will whip. To secure the necessary acidity, cream should be at least twelve hours old before it is whipped. Cream containing about 30 per cent, but- terfat and having a temperature of 50° F. or below, will whip very easily. The addition of one part of viscogen to about one hundred and fifty parts of cream will materially as- sist in whipping it, especially if it is poor in butter- fat. Cream which has been treated with viscogen will also keep sweet considerably longer than un- treated cream. To avoid too high a temperature during whipping, the cream dish and whipper should be thoroughly cooled before whipping and the whipping should be done in a cool room. CHAPTER XIV ICE CREAM As a Food and Delicacy. Ice cream is one of the most popular of all delicacies and its consumption, in recent years, has reached enormous proportions. When properly made and handled, ice cream is very wholesome and digestible. It also has considerable food value, in which respect it compares favorably with ordinary commercial cream. It furnishes, how- ever, a one-sided diet, being rich in fat and carbo- hydrates (sugar) and very poor in proteids. Value of Home Made Ice Cream. A great deal of ice cream sold on the market consists of cheap, in- ferior material. Much of it is made from old, stale cream and with large amounts of fillers and thick- eners like gelatin, corn starch, tapioca, arrow root, gum tragacanth, etc. Frequently ice cream is stored weeks before it is marketed. There is particular danger in old ice cream be- cause of the possible presence of ptomaine poisons. These poisons are the result of certain bacteria which are capable of growing at freezing tempera- tures. It is well known that every year many per- sons are poisoned by eating ice cream and such poisoning is attributable to the use of unsanitary cream and to holding ice cream too long at low temperatures. It is evident from what has been said that the safest ice cream is that which is made in the home from sweet, pasteurized cream and in which nothing but good cream, sugar and flavoring is used. 71 y2 MILK AND MILK PRODUCTS IN THE HOME Kind of Cream for Ice Cream. Use the best fla- vored sweet cream containing about 20 per cent, but- terfat and pasteurize it. To secure a good bodied ice cream, the cream must be kept cold at least six hours before freezing. This is especially important when cream is pasteurized. Freezing Process. In making ice cream the object is not only to freeze the material (mix) but to incor- porate a certain amount of air. Too much or too little air impairs the body of the finished product. Starting with cream at a temperature of about 35° F., the time required to freeze ice cream should average about twelve minutes, and to get the best consistency the temperature at the close of the freezing process should be approximately 28° F. Too quick freezing causes the water to separate from the cream, which results in a granular ice cream. Freezing too slowly reduces the overrun and tends to make the ice cream smeary. To reduce the temperature of a mass of cream be- low the freezing point, requires a freezing mixture of a low temperature. Such a mixture is secured by mixing salt and crushed ice in the proportion of one part of salt to about three of ice. The purpose of the salt is to lower the freezing point of the melting ice and to hasten the melting. To melt one pound of ice at 32° F. into water at the same temperature requires 142 heat units. Rap- idly melting ice, therefore, absorbs a large quantity of heat which, in the freezing of cream, is largely- extracted from the cream. ICE CREAM 73 The temperature of the ice cream mix when start- ing the freezer should be as near freezing as possible to prevent churning the cream. The tendency to churn is also lessened by revolving the freezer slowly the first few minutes in freezing. In packing the freezing mixture around the cream container, fill the freezer about one-third full of finely crushed ice and finish the filling by using salt and ice in the proportion of about one to three. As the ice mixture works down during the freezing process, continue adding more salt and ice as needed. The freezer should be stopped before the cream becomes too thick, else it will lose some of the air that has been incorporated as well as show a tend- ency to coarseness in texture. Yield and quality therefore demand that the freezer be stopped while the cream is still a trifle soft. Vanilla Ice Cream. To make a gallon of finished ice cream, requires about two-thirds of a gallon of cream to which should be added about one pound of sugar, which should be well mixed with the cream and allowed to dissolve before starting the freezer. Next add at the rate of about two-thirds ounce of vanilla extract and freeze. Chocolate Ice Cream. This can be made by add ing chocolate flavor to finished vanilla ice cream. 'Where a regular batch of chocolate ice cream is made, the chocolate is added before starting to freeze. Lemon Ice Cream. In making lemon flavored ice cream, use the best paper-wrapped lemons, free from 74 MILK AND MILK PRODUCTS IN THE HOME any signs of decay. Wash the lemons lightly in cold water and grate off the outer, yellowish portion of the rind, being careful not to grate off any of the white portion, which is very bitter. Mix the grated rind with sugar, using one ounce of sugar for each lemon rind. Next cut the lemons in two and squeeze out the juice, removing any seeds that may have dropped in from the squeezer. Mix the juice with the sugared rind and add orange juice to the mix- ture, using one orange to every three or four lemons. Allow the mixture to stand for about one hour, stir- ring it occasionally, and then strain. Use at the rate of one-half pint per gallon of cream. The flavor is not added to the cream until it is nearly frozen to prevent curdling it. Use two pounds of sugar per gallon of cream. Walnut Ice Cream. Use one gallon of cream, one and one-half pounds of sugar, two-thirds ounce vanilla extract and two-thirds pound of ground wal- nut meats. Freeze the same as vanilla ice cream. Other Nut Ice Creams. Chestnut, filbert, hazelnut, pecan, peanut and almond ice creams may be pre- pared essentially the same as walnut ice cream. Strawberry Ice Cream. Use one gallon of cream, one and one-half pounds of sugar and one-third quart of crushed strawberries. The fruit should be added to the cream after it is partially frozen so as not to curdle it or to have the fruit settle to the bottom. Other Fruit Ice Creams. Cherry, raspberry, pine- apple, peach, apricot, currant, grape and cranberry ICE CREAM 75 ice creams are made the same as strawberry, except that the amount of sugar is varied according to the acidity of the fruit. Packing Ice Cream. Remove the ice cream from the freezer while still in rather soft condition and put the same in packing cans which have been thor- oughly chilled by having the ice and salt packed around them about ten minutes before receiving the ice cream. Remove the brine and repack often enough to prevent melting. In the melting process the water separates and forms undesirable crystals when the cream is refrozen. The Overrun or Swell. This refers to the excess of ice cream over cream. Anything that tends to incorporate and hold air in cream conduces to a large overrun. Thus excessive beating of the cream during freezing mixes a great deal of air with it, and hence increases the overrun. A high viscosity of the cream holds the air incorporated during freez- ing. Fresh separator cream has a low viscosity, that is, does not whip well, hence will not swell so much in freezing as cream that has been kept cold for twenty-four hours. Pasteurized cream also has a low viscosity, but this will improve by keeping the cream at a low temperature a number of hours before freezing. An overrun of from 50 to 60 per cent, is about riofht. CHAPTER XV FANCY CHEESE AMERICAN NEUFCHATEL CHEESE Method of Manufacture. American Neufchatel cheese is made essentially as follows : Put a quart of milk in a suitable dish and add one drop of ren- net extract (or rennin) or one-fourth junket tablet dissolved in cold water, thoroughly mix and allow to curdle. When thoroughly curdled, pour the curd into a cheese cloth bag and hang it up to drain. When all free moisture has drained away the cheese is salted just enough to make the salt perceptible to the taste. An ordinary room temperature (70 to 75° F.) should be maintained from the time the ren- net extract is added until the cheese is finished. Neufchatel cheese is usually sold in cylindrical packages being first wrapped in oiled or parchment paper and then in tin foil. Keeping Quality. Neufchatel cheese is best when fresh. It should always be kept cold until con- sumed. Owing to its short keeping quality, it is difficult to buy this cheese in prime condition during the summer. Composition and Food Value. Neufchatel cheese has an average composition as follows: Water 50 per cent. Butterf at 24 per cent. Proteids 18 per cent. Sugar, lactic acids, etc 5 per cent. Ash 3 per cent. 100 per cent. 76 FANCY CHEESE ^'^ It will be noted that this cheese is rich in butter- fat as well as in proteids, which makes it not only a more nutritious, but also a better balanced food, than cottage cheese. The presence of butterfat also increases its palatability and digestibility. When consumed fresh, Neuf chatel is one of the most whole- some of all foods and possesses tonic value similar to that of sour milk. Its food value is practically double that of meat. Quality Varies. A great deal of so-called Neuf- chatel cheese is made from skimmilk or partially skimmed milk. The food value and digestibility of the cheese is reduced, of course, by the removal of cream from the milk. CREAM CHEESE Cream cheese is made from milk to which enough cream has been added to bring the butterfat content to about ten per cent. The method of manufacture is the same as for Neufchatel cheese. In composi- tion, digestibility and total food value it ranks well with Neufchatel cheese, but as a food it is rather unbalanced owing to the large proportion of but- terfat as will be noted from the following composi- tion: Water 44 per cent. Butterfat 40 per cent. Proteids 12 per cent. Sugar, lactic acid, etc 3 per cent. Ash 1 per cent. 100 per cent. Cream cheese is highly prized for its palatability. It is usually wrapped the same as Neufchc.el cheese yS MILK AND MILK PRODUCTS IN THE HOME) and sold in rectangular packages holding about one- fourth of a pound, CLUB CHEESE This is an exceedingly palatable cheese and is made by the following simple process : Grind up with an ordinary meat grinder one pound of old well ripened Cheddar (American) cheese and mix with one-fifth pound of good butter. To aid in mix- ing the cheese and butter they should be run through the grinder together. A second grinding is neces- sary to give a perfect mixture free from lumps. Club cheese is ideal for making sandwiches and is always best when fresh. Many persons who can- not readily digest Cheddar cheese, can eat Club cheese with impunity. This cheese is naturally very rich and should always be eaten with bread or crackers. PIMENTO CHEESE Pimento cheese is American Neufchatel cheese treated with ground red peppers. Usually from one- half to two-thirds ounce of the pepper is used per pound of Neufchatel cheese. The peppers are ground up fine by running them through a meat mincing machine, after which they are thoroughly mixed with the cheese. Pimento cheese is very popular with those who like spicy foods. It is packed in the same manner as Neufchatel cheese. A pimento flavor can be given to Club cheese in the same manner as to Neufchatel cheese. CHAPTER XVI FANCY DAIRY DISHES Junket. This wholesome and delicious dairy dish is made as follows: To a quart of sweet milk add sugar and flavoring to taste. Then heat the milk to about 90° F. ; add one junket tablet dissolved in a tablespoonful of cold water; stir vigorously for a moment and then quickly pour into the dishes in which it is to be served. Keep warm until thor- oughly curdled; then cool to 50° F. or below. In place of the junket tablet, five drops of either rennin or rennet extract may be used. It is also desirable to pasteurize the milk, but care must be taken not to heat it above 150° F. as a higher tem- perature interferes with the subsequent curdling of the milk. Junket furnishes one of the cheapest and most wholesome of dairy dishes, and is relished by nearly all people. Many persons with whom or- dinary milk does not agree, can eat junket with impunity. The reason for this is that junket is con- sumed slowly and does not curdle in the stomach like milk. Plain Bavarian Cream. This is one of the best substitutes for ice cream and is especially valuable where no ice can be had for making ice cream. The method of making Bavarian cream is as fol- lows : Thoroughly mix two egg yolks, three-fourths cup of sugar and a dash of salt. Stir slowly into this mixture three-fourths cup of scalding hot milk ; heat in double boiler and stir until it begins to 79 8o MILK AND MILK PRODUCTS IN THE HOME thicken. Remove from heat and stir in one table- spoonful of best gelatin soaked in one-fourth cup of cold water. Next add flavoring, which may con- sist of one teaspoonful of vanilla extract or the juice of either one-half orange or one-fourth lemon ; stir until gelatin is dissolved, and strain. When cold and beginning to set, whip a few minutes with egg beater and then stir in lightly one cup of whipped cream and pour mixture into a mold to harden. Chocolate Bavarian Cream. Cook until smooth two ounces of melted chocolate, one-fourth cup of sugar and one-fourth cup of boiling water. Add this to the milk used for custard and proceed as in mak- ing plain Bavarian cream. Charlotte Russe. Soak one tablespoonful of best gelatin in one-fourth cup of cold water and add one- third cup of scalding hot cream; stir in one-third cup of powdered sugar and one teaspoonful of vanilla extract. Next fold in three cups of whipped cream. Line mold with lady-fingers and pour mix- ture into it and chill. Charlotte Russe, like the Bavarian cream, is a good substitute for ice cream, being very rich and palatable. Devonshire Cream. Pour a quart of rich, fresh milk into a small double boiler and keep cold for about twelve hours to allow most of the cream to rise. Next gradually raise the temperature to about 180° F., being careful not to disturb the cream in any way. The temperature must be raised very FANCY DAIRY DISHES 8l slowly, averaging about two degrees per minute. Keep hot for a number of hours, or until a stiff, crusty layer of cream has formed, and then cool. Remove the cream with a flat, perforated skimmer. This cream has a very delicious flavor and is often eaten with bread, either sweetened or unsweetened. Cream prepared in this way is very thoroughly pasteurized and is therefore an entirely safe and wholesome food. CHAPTER XVII BUTTER AND OLEOMARGARINE BUTTER Food Value. Butter is composed principally of butterfat as seen from the following average compo- sition : Water 14 per cent. Butterfat 83 per cent. Proteids 1 per cent. Salt 2 per cent. 100 per cent. As a rule butter is used for its palatability, that is, as a relish with other foods such as bread. Yet butter has also a very high food value. In this con- nection it should be remembered that a pound of fat has an energy or heat value equal to two and one- fourth pounds of either proteids or carbohydrates. Compared with other fats such as lard, for ex- ample, butter seems rather expensive. But in plac- ing a value upon butter it is necessary to give due consideration to its palatability and high degree of digestibility. The latter is especially important, par- ticularly with invalids and persons suffering from weak digestion. Process of Manufacture. The best butter is made by churning sour cream. The acidity adds flavor to the butter and also facilitates churning. Cream should contain about 30 per cent, butterfat and 0.5 per cent, acid when it enters the churn, and the tem- perature should be such as to bring butter in about 82 BUTTER AND OLEOMARGARINE 83 thirty-five minutes. The average churning tempera- ture is about 58° F. Churning consists in agitating the cream, which causes the microscopic fat globules to combine into masses visible in the churn as butter granules. When these granules are about the size of half a pea, the buttermilk is removed, the butter rinsed with cold water and salt added at the rate of about one ounce per pound of butter. The salt is thor- oughly worked through the butter with a butter ladle, after which it is usually molded into rectan- gular ''prints" weighing one pound. Judging Butter. Butter is briefly judged or scored according to the following score card: BUTTER SCORE CARD Perfect Actual Score Flavor 45 Texture 25 Color 15 Salt 10 Package 5 Total 100 Defect r Light Rancid I Fishy J Weedy I Stable Unclean I High acid I Bitter fPoor grain Cloudy brine Too much brine Greasy [Mottled, wavy ! White specks I Too high I Too light fToo much salt -j Undissolved salt [Lacks salt r Dirty ! Poorly packed 1 Poorly nailed [Poorly lined 84 MILK AND MILK PRODUCTS IN THE HOME Flavor. Immediately after the sample of butter is withdrawn from the package it should be held under the nose to ascertain the quality of the aroma (flavor). Strictly speaking, flavor refers to the taste. But the use of the term flavor in butter judg- ing usually includes both taste and aroma, the emphasis resting upon the latter. It is difficult to describe an ideal butter flavor. It may perhaps be likened to the flavor of clean, well ripened cream. Light flavor is generally due to churning cream too sweet. It may be due also to too much washing. Rancid flavor is due chiefly to overripened cream. The age of the milk, cream and butter is also fre- quently the cause of rancidity. Good butter exposed to light and air at ordinary temperatures turns ran- cid in a very short time. Weedy flavors are caused by cows feeding on weeds. Leeks or wild onions are frequently the cause of very serious trouble when cows have free access to them. The trouble may also be caused by exposing milk and cream to an atmosphere charged with objectionable odors. Fishy flavor, according to L. A. Rogers, is due to oxidation which is favored by a high acid cream and overworking. The latter favors oxidation by in- creasing the amount of air in butter. Stable flavor is caused by lack of cleanliness in milking, and by keeping milk too long in or near a dirty stable. Unclean flavors are caused by dirty pails, strain- ers, cans and general uncleanliness in the care and handling of milk. BUTTER AXD OLEOMARGARINE 85 High acid flavor is due to oversoured cream. Bitter flavor is caused by keeping cream too long at low temperatures. Texture. An ideal texture is indicated by a some- what granular appearance when a piece of butter is broken, an appearance quite similar to that of the broken ends of a steel rod. Brine refers to the amount and character of the water in butter. It should be as clear as water and not present in such quantities as to run off the trier. Too much brine is caused chiefly by underworking and by churning to small granules. Cloudy brine is caused by churning at too high a temperature and also by granulating too coarse. In- sufficient washing has a tendency to produce a cloudy brine. Poor grain is caused by overworking and over- churning; also by too high temperatures in churn- ing and working. Greasy butter is caused by overworking or by handling at too high temperatures. Color. The essential thing in color is to have it uniform. It should have a little deeper shade than that produced by June pasturage. Artiflcial color- ing is therefore necessary. Mottles are discolorations in butter caused by the uneven distribution of salt. White specks are due either to curd particles in cream caused by overripening and lack of stirring during ripening, or to dried and hardened cream. Salt. As with color, the essential thing with salt is to have it evenly worked through the butter and none of it should remain undissolved. 86 MILK AND MILK PRODUCTS IN THE HOME OLEOMARGARINE Oleomargarine is a cheap substitute for butter and, on account of its cheapness, has found extensive sale in recent years. This product is also known as margarine or butterine. The principal component of oleomargarine is beef fat. The lower grades contain a high percentage of cottonseed oil, while the best grades contain some butterfat. Composition. In the twelfth report of the Govern- ment Census, the proportions of the raw materials Avhich enter into the composition of the different grades of oleomargarine are given as follows : HIGH GRADE OLEOMARGARINE Oleo oil 100 pounds Neutral lard 130 pounds Butter 95 pounds Salt 32 pounds Color 00.5 pound MEDIUM HIGH GRADE OLEOMARGARINE Oleo oil 315 pounds Neutral lard 500 pounds Cream 280 pounds Milk 280 pounds Salt 120 pounds Color 001.5 pounds CHEAP GRADE OLEOMARGARINE Oleo oil 495 pounds Neutral lard 265 pounds Cotton seed oil 315 pounds Milk 255 pounds Salt 120 pounds €^lor 001.25 pounds BUTTER AND OLEOMARGARINE 87 Digestibility. It has often been claimed that oleomargarine has all the merits possessed by gen- uine butter. This claim, however, does not seem to hold in respect to digestibility. Eminent chemists and food experts have long contended that no fat is equal to butterfat in digestibility. Both the phys- ical and chemical properties of butterfat offer good reason for such belief. It has already been learned that butterfat exists in milk in an extremely finely divided condition and that one of the distinguishing characteristics of butterfat is its relatively high con- tent of soluble fats or fatty acids. These conditions undoubtedly materially favor ease of digestion. A number of recent experiments add much positive evidence in support of this belief. It has been learned, for example, that butterfat is considerably more nutritious than such fats as lard oil and al- mond oil, and this superiority may be due to a higher degree of digestibility. Color. Oleomargarine has naturally a whitish color, which is of value in distinguishing this product from butter. That some distinguishing mark is necessary is evinced by the fact that a great deal of oleomargarine in the past has been sold as butter. Indeed, deception has been practiced to such an extent that the federal government, for a number of years, has levied a heavy tax on every pound of oleomargarine colored in imitation of gen- uine butter. The result is that comparatively little colored oleomargarine is manufactured at the pres- ent time. 88 MILK AND MILK PRODUCTS IN THE HOME RENOVATED OR PROCESS BUTTER This is old, stale, rancid butter which has been purified by forcing air currents through the melted fat and rechurning this mixed with milk or cream. To protect the consumer, the law requires that all butter which has undergone this treatment, be labeled Process or Renovated Butter. When packed in tubs, the label appears on the tub and the dealer may easily sell such butter to consumers as genuine butter. This furnishes an instance where butter put up in pound prints protects the consumer against an imitation product. CHAPTER XVIII COMMON CHEESE CHEDDAR OR AMERICAN CHEESE Formerly the term "Cheddar'' was applied ex- clusively to what is noAV commonly known as Amer- ican cheese. This cheese belongs to the so-called hard type of cheeses. Briefly Cheddar cheese is made by precipitat- ing the curd of milk by means of rennet extract. The curd is allowed to ferment until it has reached the right stage of moisture and acidity, when it is salted and then molded under heavy pressure. After pressing the cheese must undergo a long and careful curing or ripening process during Avhich most of the insoluble curd is changed to soluble products. Food Value. Cured Cheddar cheese has an aver- age composition as follows : Water 34 per cent. Butterfat 34 per cent. Proteids 26 per cent. Sugar, etc 2 per cent. Ash 4 per cent. 100 per cent. From the composition it is seen that Cheddar cheese is an extremely rich food, one pound being equal to about two pounds of meat. It is a yery economical substitute for meat. In the New York City penny lunches, cheese sandwiches furnished the largest amount of nutrients procurable for a penny. 89 90 MILK AND MILK PRODUCTS IN THE HOME Owing to its richness, this cheese is best adapted to the diet of people doing hard physical labor. While in digestibility Cheddar cheese ranks well with other staple foods, it is well known that many people with weak stomachs cannot readily digest it. Under all conditions the cheese should be con- sumed with bulky foods, such as bread and crackers. When eaten alone or in connection with other rich foods, it has a tendency to produce constipation. Important Qualities. Age is important in Ched- dar cheese, because the real cheese flavor requires about six months to develop. Of even greater im- portance is the softening of the texture which also follows with age. A green or fresh cheese has a tough, curdy or rubbery texture which means that the casein is still insoluble and that the ^cheese is hard to digest. An ideal textured cheese is solid and waxy. A soft, pasty or sticky cheese is undesirable because it carries too much moisture. Corky cheese lacks moisture, while mealy or crumbly cheese is the result of too much acid and, like corky cheese, is un- desirable. Cheese is commonly judged on the basis of 45 points for flavor, 30 points for texture, 10 points for color and 15 points for finish and appearance. BRICK AND SWISS CHEESE These cheeses have essentially the same composi- tion and food value as Cheddar cheese. But the methods of manufacture differ from the Cheddar process, which accounts for the difference in flavor and texture. COMMON CHEESE 91 The texture of these cheeses must be mellow, waxy and plastic like that of Cheddar cheese, but more or less porous. In brick cheese small, irregular open- ings are characteristic, while large, smooth round holes are typical of the best Swiss cheese. Swiss and brick cheese, like Cheddar, must under- go a thorough curing process to develop flavor and to break down the insoluble casein into soluble prod- ucts. CHAPTER XIX PRODUCTION OF CLEAN WHOLESOME MILK During the past few years a great campaign has been carried on in the interest of cleaner milk, and while great improvements have followed this, there is still a great deal of unsanitary milk placed upon Figure 15 — A sanitary cow stable the market. The essential steps in securing clean, wholesome milk are briefly discussed in the follow- ing paragraphs. Clean, Healthy Cows. The cow's health is of prime importance, and all milk from cows affected with any kind of disease should be rigidly excluded from the dairy. Under ordinary conditions the cow is the main source of dirt in milk. The rubbing of the milker against her and the shaking of the udder during milking, will dislodge numerous dust particles and hair and these are liable to get into the milk unless special precautions are taken to keep them out. 92 PRODUCTION OF CLEAN WHOLESOME MILK 93 When we consider that every dust particle and every hair that drops into the milk may add hun- dreds, thousands, or even millions of bacteria to it, we realize the importance of taking every precaution to guard against contamination from this source. To keep cows as free as possible from loose hair, dust and manure particles, they should be carded and brushed regularly. This should be done at least an hour before milking to avoid dust. Five to ten minutes before the cow is milked her udder and flanks should be gently washed with clean, tepid water, by using a clean sponge or cloth. This will allow sufficient time for any adhering drops of water to drip off, at the same time it will keep the Figure IG — Clean milkin; 94 MILK AND MILK PRODUCTS IN THE HOME udder and flanks sufficiently moist to prevent dis- lodgment of dust particles and hair during milking. Cows should be kept only in clean, light, venti- lated stables and must be turned out daily for exer- cise excepting in the most inclement weather. The Milkers. Clothes which have been worn in the field are not suitable for milking purposes. Every milker should be provided with a clean suit con- sisting of cap, jacket and trousers. Milkers should also wash and dry their hands before milking, and, above all, keep them dry during milking. Much disease transmitted through milk has had its origin in diseased milkers. The health of the milker is therefore a matter of prime importance. Milk Vessels. All tin ware used in the handling of milk should be made with as few seams as pos- Fi§:ure 17 Figure 18 Unliushed seam Flushed seam sible. Wherever seams occur, they should be flushed with solder. Unflushed seams are difficult to clean and as a rule afl'ord good breeding places for bac- teria. Figure 17 illustrates the character of the PRODUCTION OF CLEAN WHOLESOME MILK 95 unflushed seam; Figure 18 shows a flushed seam which fully illustrates its value. Figure 19 illustrates a modern sanitary milk paiL The value of a partially closed pail is evident from the reduced opening, which serves to keep out many bac- teria and much dirt that would otherwise drop into the pail during milking. All utensils used in the han- dling of milk should be as nearly sterile as possible. A very desirable method of clean- Figure 19 iug them is as follows: Covered milk pail -r-i' , • -ji First, rnise with warm or cold water. Second, scrub with moderately hot water containing some washing powder. The wash- ing should be done with a brush rather than cloth because the bristles enter into crevices which the cloth cannot possibly reach. Furthermore, it is very difficult to keep the cloth clean. Third, after rinsing, scald thoroughly with steam or hot water. After scalding, the utensils should be inverted upon shelves without wiping and allowed to remain so until ready to use. This will leave the vessels in a practically sterile condition. Fourth, if it is possible to turn the inside of the vessels to the sun in a place where there is no dust, then it is desirable to expose the utensils during the day to the strong germicidal action of the direct sun's rays. Flies. Flies not only constitute a prolific but also a dangerous source of milk contamination. These 96 MILK AND MILK PRODUCTS IN THE HOME pests visit places of the worst description and their presence in a dairy suggests a disregard for cleanli- ness. Of 414 flies examined, the average number of bacteria carried per fly was one and a quarter mil- lions. Flies should be rigidly excluded from all places where they are apt to come in contact with the milk. Other Conditions. Cows, of course, should have pure water and clean wholesome feed. Highly fer- mented brewers' grains and strong weeds are es- pecially objectionable. The water of ponds and stagnant streams is also harmful. Not only is such water injurious to the health of cows, but by wad- ing in it they become contaminated with numer- ous undesirable bacteria, some of which may later find their way into the milk. Clean stables, clean barnyards and clean bedding must be provided to keep the cows clean. The details considered in the production of clean, wholesome milk are shown in the following score card, prepared by the Official Dairy Instructor's Association and used by the federal government. In this score card 40 points are allowed for equip- ment and 60 points for methods, in producing milk. PRODUCTION OF CLEAN WHOLESOME MILK 97 SCORE CARD EQUIPMENT COWS Health Apparently in g:ood health 1 If tested with tuberculin once a year and no tuberculosis is found, or if tested once in six- months and all reacting animals removed 5 (If tested only once a year and reacting animals found and removed, 2.) Comfort Bedding 1 Temperature of stable 1 Food (clean and wholesome) Water Clean and fresh 1 Convenient and abundant 1 STABLE3 Location of stable Well drained 1 Free from contaminating surroundings 1 Construction of stable Tight, sound floor and proper gutter 2 Smooth, tight walls and ceiling ' Proper stall, tie and manger 1 L ight, four sq. ft. of glass per cow (Three sq. ft., 3; 2 sq. ft., 2; 1 sq. ft, 1. Deduct for uneven distribution.) Ventilation : Automatic system Adjustable windows 1 Cubic feet of space for cow; 500 to LOOO feet (Less than 500 ft., 2; less than 400 ft., 1; less than 300 ft, 0; over 1,000 ft., 0.) UTENSILS Construction and condition of utensils Water for cleaning . . . (Clean, convenient and abundant.) Small-top milking pail Facilities for hot water or steam (Should be in milk house, not in kitchen.) Milk cooler Clean milking suits MILK ROOM Location of milk room P'ree from contaminating surroundings 1 Convenient 1 Construction of milk room Floor, walls and ceiling ' Light, ventilation, screens 1 Tctal SCORE Perfect Allowed 98 MILK AND MILK PRODUCTS IN THE HOME SCORE CARD— Continued METHODS SCORE Perfect | Allowed COWS Cleanliness of cows STABLES Cleanliness of stables Floor 2 Walls 1 Ceiling and ledges 1 Mangers and partitions 1 Windows 1 Stable at milking time Barnyard clean and well drained Removal of manure daily to field or proper pit.. . (To 50 feet from stable, 1.) MILK ROOM Cleanliness of milk room UTENSILS AND MILKING Care and cleanliness of utensils Thoroughly washed and sterilized in live steam for 30 minutes 5 (Thoroughly washed and placed over steam jet. 4; thoroughly washed and scalded with boiling water, 3; thoroughly washed, not scalded, 2.) Inverted in pure air 3 Cleanliness of milking Clean, dry hands 3 Udders washed and dried 6 (Udders cleaned with moist cloth, 4; cleaned with dry cloth at least 15 minutes before milking, 1.) HANDLING THE MILK Cleanliness of attendants Milk removed immediately from stable Prompt cooling (cooled immediately after milking each cow) Efficient cooling; below 50° F (51° to 55°, 4; 56° to 60°, 2.) Storage below 50° F (51° to 55°, 2; 56° to 60°, 1.) Transportation ; iced in summer (For jacket or wet blanket, allow 2 ; dry blanket or covered wagon, 1.) Total Equipment.... + Methods.,.. = ....FINAL SCORE NOTE 1.— If any filthy condition is found, particularly dirty utensils, the total score shall be limited to 49. NOTE 2.— If the water is exposed to dangerous contamination cr there is evidence of the presence of a dangerous disease in animals or attendants, the score shall be 0. INDEX Page Acidity of milk 17 Albumen 10 American cheese 89 Ash of milk 10 Bacteria 19 beneficial 20 disease 33 effect of temperature on 23 lactic acid 20 numbers in milk 22 rapidity of growth 19 spores of 21 undesirable 21 Bavarian cream 79 Brick cheese 90 Butter 82 color of 85 composition of 85 digestibility of 82,87 flavor of 84 food value of 82 judging of 83 manufacture of 82 process 88 renovated 88 texture of 85 Butterfat 11 Buttermilk, natural 57 tablets 61 Charlotte Russe 80 Cheese, American 89 brick 90 club 78 common 89 cottage •. 64 Page cream 77 Neufchatel 76 pimento 78 Swiss 90 Casein 10 Certified milk 27 Club cheese 78 Condensed milk 53 Cream 66 Bavarian 79 composition of 66 Devonshire 80 food value of 67 homogenizing 69 judging of 30 pasteurization of 67 physical properties of.. 16 specific gravity of 16 visco 69 viscosity of 16 whipping of 69 Cream cheese 77 Dairy thermometer 41 Devonshire 80 Diphtheria epidemics .... 36 Enzymes 12 Evaporated milk 54 Ice cream 71 chocolate 73 fruit 74 lemon 73 manufacture of 72 nut 74 vanilla 73 99 100 INDEX Page Judging milk and cream. 30 butter 83 Junket 79 Lactic acid cultures 59 Milk 9 absorbing powers of... 17 acidity of 17 bacteria in 19 certified 27 color of 17 composition of 9 condensed, sweetened. .53 cooling of 24 digestibility of pasteur- ized 43 disease bacteria of.... 33 epidemics of 35 evaporated 54 from different breeds.. 14 from goats 51 handling of 25 judging of 30 market classes of 27 modified 44 pasteurized 37 physical properties of. 16 production of clean.... 94 score card for 30 solids 12 sour 56 specific gravity of 16 sugar 10 Page use of 15 value of clean 15 vessels 94 vessels, cleaning .of. . . .95 viscosity of 16 Neufchatel cheese 76 Oleomargarine 86 color of 87 composition 86 digestibility of 87 Pasteurization 37 necessity for 37 by milk dealers 38 advantages of, in home. 41 inefficient .42 Pimento cheese 78 Scarlet fever epidemics. .36 Septic sore throat 36 Skimmilk 63 sour 58 Specific gravity of milk.. 16 Swiss cheese 90 Tuberculosis 34 Typhoid epidemics 36 Viscogen 67 Whey, value of 50 preparation of 63 H 4 ?! %'^''\^'' \''^^'\^

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