WOMAN'S INSTITUTE LIBRARY OF COOKERY. VOLUME 2: MILK, BUTTER AND CHEESE; EGGS; VEGETABLES TEXT

as they may well be called, consists in adding to sweet milk tablets containing lactic acid or a certain culture of bacteria that induce fermentation, very much as yeast does, and then keeping it at about body temperature for a number of hours in order to allow the milk to thicken and sour. Such milks exert a beneficial action in the digestive tract, and their food value, provided they are made from whole milk, is just as high as that of the original sweet milk. Artificial buttermilks therefore prove a valuable source of food supply for persons who find them palatable and who do not care for sweet milk. Their food value may be increased by adding cream to them. 18. SOUR MILK.--Ordinary milk contains large numbers of bacteria that produce fermentation. When it is allowed to stand for some time, these bacteria act upon the sugar, or lactose, contained in the milk and change it into lactic acid. This acid gives to the milk a sour taste and at the same time causes the casein of the milk to become a mass known as _curd_, or _clabber_. This mass continues to grow sour and tough until all the milk sugar is converted into lactic acid, so that the longer the milk stands, the more acid it becomes. Sour milk, however, is useful in the preparation of various dishes, such as hot breads and griddle cakes. [Illustration: FIG. 1] 19. WHEY.--When the curd is completely removed from milk, as in making cheese, a clear, light, yellowish liquid known as whey remains. Whey is composed of water, minerals, and milk sugar or lactic acid, and is the least valuable part of the milk. The ingenious housewife will never be at a loss to make use of this product, for, while its food value is slight, the minerals it contains are important ones. Whey is sometimes used to furnish the liquid for bread making and, in addition, it may be used as a beverage for persons who cannot digest food as heavy as milk itself. 20. COMPARISON OF FOOD VALUES OF MILK PRODUCTS.--So that the housewife may become familiar with the food values of milk products, there is here given, in Fig. 1, a graphic table for the comparison of such products. Each glass is represented as containing approximately 1 pint or 1 pound of the milk product, and the figures underneath each indicate the number of calories found in the quantity represented. The triangle at the side of each indicates the proportion of ash, protein, fat, carbohydrate, and water, the percentage composition being given at the side. Housewives as a rule fully appreciate the food value that is to be found in whole milk and cream, but such products as skim milk, buttermilk, and whey are likely to be ignored. CHARACTERISTICS OF WHOLESOME MILK 21. So far as the housewife is concerned, the qualities that characterize wholesome milk are without doubt of great interest. She may know of what use milk is in the diet and the food substances of which it is composed, but unless she understands just what constitutes milk of good quality, as well as the nature of inferior milk, she cannot very well provide her family with the kind it should have. Therefore, to assist her in this matter, the characteristics of wholesome milk are here discussed. Such milk, it will be well to note, must be of the right composition, must not be adulterated, must be fresh--that is, not older when delivered than is permitted by law--and must be as clean as possible. 22. STANDARD OF MILK COMPOSITION.--The housewife usually judges the quality of milk by the amount of cream that rises to the top when milk in a bottle is allowed to remain undisturbed for some time. This is really an excellent test, because milk that contains only a small amount of cream is of poorer quality than that which contains a larger amount; in other words, the more cream milk contains, the higher will be its food value and the greater its energy-producing ability. Then, too, milk that is rich in cream usually contains proportionately large amounts of protein and sugar. While the composition of milk has much to do with the quality of this food, it varies, as should be noted, in different breeds and even in individual cows, depending on both the food and the care given to them. For this reason, milk that is mixed is preferable to the milk of a single cow, as the mixing of the milk of a number of cows insures a better average composition. 23. ADULTERATION OF MILK.--The composition of milk, and hence its quality, is seriously affected by its adulteration. By this is meant the extraction of any of the food substances from whole milk; the addition of anything that tends to weaken or lower its quality or strength; the use of coloring matter to make it appear of greater value than it actually is; or the use of preservatives to prevent it from souring as soon as it ordinarily would. It is, of course, illegal to adulterate milk, yet it is sometimes done. The most convenient and possibly the most common materials used to adulterate milk are water and skim milk. The addition of water to milk decreases the quantity of all its food substances, but the addition of skim milk reduces the quantity of fat only. The color of the milk is often affected by the use of these adulterants, but when this happens, yellow coloring is usually added to restore the original appearance. Sometimes the milk that a dairyman markets contains more fat than the law requires; but even such milk cannot legally be skimmed nor diluted with skim milk. The only thing that may be done to it is to mix it with milk that is low in butter fat and thus obtain a milk that will average the legal percentage. For instance, if milk from a dairy averages 5 per cent, of butter fat, it may be diluted with milk that contains only 3 per cent, of butter fat, because the result of such mixing, which will be milk averaging 4 per cent, of this food substance, will be the legal standard. 24. To prevent milk from souring, dishonest milk dealers often put into it such preservatives as soda, borax, and formaldehyde. There is no definite way of telling whether or not one of these has been used, except by a chemical analysis. However, if milk does not sour within a reasonable time when no precautions have been taken to keep it sweet, it should be looked on with suspicion, for it undoubtedly contains a preservative. 25. FRESHNESS OF MILK.--To be most satisfactory for all purposes, milk should be absolutely fresh. However, it is almost impossible to obtain milk in this condition, because it is generally sold at a distance from the source of supply. Milk that is sold in small towns and cities is usually 12 and often 18 to 21 hours old when it is delivered; whereas, in large cities, where the demand is so great that milk must be shipped from great distances, it is often 24 to 36 or even 48 hours old when it reaches the consumer. In order that milk may remain sweet long enough to permit it to be delivered at places so far removed from the source of supply, it must be handled and cared for in the cleanest possible way by the dealers. Likewise, if the housewife desires to get the best results from it, she must follow the same plan, cooling it immediately on delivery and keeping it cool until it is consumed. The freshness of milk can be determined only by the length of time it will remain sweet when proper care is given to it. 26. CLEANLINESS OF MILK.--Milk may be of the right composition, free from all adulteration, and as fresh as it is possible to obtain it, but unless it is clean, it is an injurious food. Milk is rendered unclean or impure by dirt. In reality, there are two kinds of dirt that may be present in milk, and it is important to know just what these are and what effect they have on milk. 27. The less harmful of the two kinds of dirt is the visible dirt that gets into the milk from the cow, the stable, the milker, the milking utensils, and similar sources when these are not scrupulously clean. If milk containing such dirt is allowed to stand long enough in pans or bottles for the heavier particles to settle, it will be found as sediment in the bottom of the receptacle. To say the least, the presence of such dirt is always disagreeable and frequently produces foreign flavors. Straining the milk through clean absorbent cotton will reveal the presence of such dirt and another kind of dirt that does not show through the opaque fluid. This second kind of dirt is generally found in milk when the first kind is present in any quantity. It is more liable to be harmful than the other, because it enters the milk from the water used in cleaning the receptacles or from some contaminated source. [Illustration: FIG. 2] 28. Whenever dirt is present in milk, bacteria are sure to be there; and the greater the quantity of dirt the greater will be the number of bacteria. Should the housewife desire to compare the cleanliness of several lots of milk, she may filter a like quantity from each lot, say a quart or a pint, through small disks of absorbent cotton. If, after the milk has passed through the cotton disk, very little dirt remains on it, as in Fig. 2 (_a_), the milk may be considered as comparatively clean; if the cotton disk appears as in (_b_), the milk may be said to be only slightly dirty; if it appears as in (_c_), the milk is dirty; and if it appears as in (_d_), the milk is very dirty. Milk that leaves a stain like that in (_d_) contains more bacteria than milk that leaves a stain like that in (_c_), and so on through all the lots of milk. Filtering milk in this manner, however, does not indicate whether the bacteria are disease producing. Such information can be secured only by microscopic examination, and only then by persons who have a knowledge of such matters. 29. Since, as has been pointed out, bacteria cling to all dirt, the dirt that milk contains is one of the causes of souring and putrefaction of milk, and may be a cause of disease. Indeed, it is definitely known that dirty milk sours much more quickly than does clean milk. Actual tests in which clean milk was put in a cool place have proved that it will keep for weeks, whereas dirty milk will sour in a day or two, especially in warm weather. This information should point out clearly to the housewife that it is not merely heat that changes milk or causes it to sour. She should understand in addition, that bacteria grow and multiply very rapidly when conditions for their growth are provided. These conditions are moisture, warmth, and the right kind of food, and as all of these are found in milk, this product is really ideal for bacterial development. The only way in which to protect milk is to make sure that no bacteria enter it, or, if they do, to make it impossible for them to grow. This may be done by keeping the milk so cold that they cannot thrive, or by destroying them in various ways, which are taken up later. 30. In former times, there was not much danger of wide-spread disease from the milk supply, for it was cared for almost entirely by those who kept a few cows and distributed milk to a small number of customers. In fact, it has been only within the past 50 years that large quantities of milk are handled by separate dairies and shipped great distances from the source of supply and that the distribution of milk has become a great industry. When so much milk is handled in one place, it is more or less unsafe unless the dairy is kept extremely clean and is conducted in the most sanitary manner. Experience has shown that too much attention cannot be given to the care of milk, for the lives of great numbers of children have been sacrificed through the carelessness of dairymen and persons selling and distributing milk, as well as through the negligence of those who handle the milk after it has entered the home. To overcome much of this carelessness, both the Federal Government and the various states of this country have set standards for safe milk production, and in order to make their laws effective have established inspection service. Independently of these state and national laws, many of the cities, particularly the large ones, have made their own standards, which, as a rule, are very rigid. One of the usual requirements is to compel each person who wishes to sell milk in the city to buy a license, so that the city authorities may keep in touch with those handling milk and so that conditions may be investigated at any time. In view of the care required of dealers in handling milk, the housewife owes it to herself and the members of her family to keep the milk in the home in the best possible manner. GRADES OF CLEAN MILK 31. Ever since milk has come to be a commercial product, authorities have been devising ways in which it may be brought to the consumer in a condition that will permit it to be used without causing ill results. Their efforts have been rewarded to such an extent that nowadays consumers have little to fear from the milk they purchase, provided they get it from dealers who live up to the laws. Chief among the different grades of clean milk is _certified milk,_ and next in order comes _pasteurized milk,_ followed by _sterilized milk_. 32. CERTIFIED MILK.--The grade of clean milk sold under the name of certified milk is simply natural, raw milk that is produced and marketed under conditions that permit it to be guaranteed as pure, wholesome, and of definite composition. Such milk is necessarily higher in price than milk that is less wholesome and sanitary, because of the extra cost to the dairyman in meeting the requirements that make it possible for him to produce clean milk under sanitary conditions. These requirements pertain to the health and cleanliness of those who handle the milk, to the health, housing condition, and care of the herd and the dairy cows, and to the handling and care of milk in the dairy and during transportation and delivery. They are usually established and enforced by an inspection commission appointed by the city, county, or state in which the milk is produced. 33. If a little careful thought is given to the milk situation, it will be admitted that such precautions are necessary if clean milk is to be the result. Such milk cannot be produced if the surroundings are dirty, because dust and flies, which are two sources of contamination, are practically always present in such places. A stable with poor ventilation, without screens to keep out flies, and with floors that will not permit of cleaning, but cause filth and refuse to accumulate, is sure to contaminate milk that is handled in it. In addition, cows that are not well fed, comfortably housed, or carefully groomed cannot be expected to give milk of as good quality as cows that are properly cared for. Likewise, if the persons who do the milking are not clean, the milk is subject to contamination from this source. 34. All such unfavorable conditions can be remedied, and must be in the production of certified milk; but the good accomplished in this direction will be lost if the milk is carelessly handled after milking. Therefore, in producing certified milk, only the cleanest water available is allowed to be used in the dairy. Impure water is a common source of the contamination of milk in such places. On some farms, the water supply comes from a well that is too near the barn or that is too shallow to avoid being made impure by the germs that filter into it from the barnyard or a cesspool. If vessels in which milk is placed are washed in such water, it is necessary to sterilize them by boiling or steaming before milk is put into them, in order to kill the germs that come from the water. If such a precaution as this is not observed, the germs will multiply rapidly in the milk and, provided they are disease-producing, will make the milk extremely dangerous. Besides observing the precautions mentioned, it is necessary that all utensils used in a dairy, such as pails for milking, strainers, containers, etc., be kept scrupulously clean. Likewise, they must be sterilized by boiling each time they are used, for, while disease germs may be absent, those which cause the milk to sour are always present and must be destroyed. Finally, to prevent any germs that enter milk from multiplying, even when it is properly cared for, the milk has to be cooled to a temperature of 45 degrees Fahrenheit or lower immediately after milking and then bottled in sterilized bottles, sealed, and packed in ice, within 20 minutes after milking. 35. It is by giving attention to all such matters that certified milk is possible. Such milk, as will be understood from what has been said, is neither a cooked milk nor a dirty milk that is processed, but a natural, raw milk that is clean at all stages of its production and marketing. Because of this fact, it is the best and cleanest milk to be had and may be used without hesitation, not only by grown persons in good health, but for infants and invalids. The sanitary condition of certified milk and the consequent length of time it will remain sweet was demonstrated conclusively as far back as 1900 at the Paris Exposition. At this time, two model dairies in the United States--one located at the University of Illinois and the other at Briarcliff Manor, Westchester County, New York--delivered to their booths at the Exposition milk that was bottled under the most sanitary conditions at their dairies. During its transit across the ocean the milk was kept at a temperature of 40 to 42 degrees Fahrenheit, and on its arrival, 2 weeks after leaving the dairies, it was found to be in a perfectly sweet condition. Similar experiments made at later dates, such as shipping certified milk from the East to California, serve to bear out the test made in 1900, and prove what can be done with milk so produced as to be as free as possible from bacteria or the conditions that permit their growth. 36. PASTEURIZED MILK.--While certified milk is undoubtedly the safest kind of milk to use and is constantly growing in favor, much of the milk received in the home is pasteurized. By pasteurized milk is meant milk that has been heated to a temperature of 140 to 155 degrees Fahrenheit, kept at this temperature for 15 to 20 minutes, and then cooled rapidly. The result of such a treatment is that any disease-producing germs that are present in the milk, as well as those which are likely to cause intestinal disturbances, are destroyed, and that the milk is rendered safe as food for a time. Pasteurizing does not materially change the taste of milk, nor does it seriously affect the digestive properties of this food. It is true, of course, that pasteurized milk is not so good as clean raw milk. Still it is better to use such milk than to run the risk of using milk that might be contaminated with the germs of tuberculosis, typhoid fever, scarlet fever, diphtheria, or any other of the numerous diseases that have been known to be carried to whole families and communities through the milk supply. 37. Although pasteurizing is done on a large scale in dairies, there is no reason why the housewife cannot pasteurize the milk she buys, provided it is raw milk and she feels that it is not safe to use. If pasteurizing is to be done frequently and large quantities of milk are to be treated, it would be advisable to purchase the convenient apparatus that is to be had. However, if only a small quantity of milk is to be pasteurized at a time, a simple improvised outfit will prove satisfactory, because milk pasteurized in the home may be heated in the bottles in which it is received. Such an outfit consists of a dairy thermometer, a deep vessel, and a perforated pie tin or a wire rack of suitable size. 38. To pasteurize milk in the home, proceed in the manner illustrated in Fig. 3. Place the rack or invert the perforated pie tin in the bottom of the vessel, and on it place the bottles of milk from which the caps have not been removed. Make a hole through the cap of one bottle, and