—By the term “milk,” unless qualified in some way, is meant a lacteal secretion of the healthy cow, free of colostrum and of standard quality. If the milk of other mammals is meant the name of the class of animal is used in connection with the term, such as ewe’s milk, goat’s milk, etc. Milk is one of the most important articles of commerce and, by reason of its composition, high nutritive character, and easy digestibility, it is not only the natural food of infants but a most important food for children and adults. It is also an indispensable food in many, if not most, cases of disease where nutrition is impaired. In some cases life may often be sustained over a critical period by the use of milk as a food where other forms of food would fail of digestion and prove injurious instead of beneficial.
The United States standard for milk is found in Appendix A.
—Perhaps there is no food substance which has been subjected to so many and such severe analytical tests as milk. Hundreds of thousands of analyses have been made in all civilized countries, not only of the milk of the individual cow but of herds of greater or less size.
There is a great variation in the composition of milk in different breeds of cattle and also in different individuals of the same breed. For instance, the Holstein breed of cattle affords a milk with a very low content of fat, sometimes as low as 3.25 percent, and in individual cases lower. On the other hand the Jersey breed of cattle affords a milk of a very high content of fat, sometimes reaching as high as 6 percent, and in individual cases very much higher. The content of the nitrogenous element in milk is more stable than that of fat and the common content of casein in milk ranges from 21⁄2 to 31⁄4 percent. The sugar in the milk is usually the complementary substance with the fat, diminishing in relative proportions as the fat increases and vice versa. The average content of sugar in cow’s milk is approximately 4 percent. The content of mineral substances in milk is also quite constant, being about 0.70. The ash contains the phosphoric acid which is one of the essential food components of milk. A milk of fair average quality contains 12 percent of solids and 88 percent of water. This is an expression for milk during the various seasons of the year and from all breeds and kinds of cows. The influence of season has much to do with the quantity of milk produced. It is always greater in the spring and summer months, when the cows are turned out to pasture and the growth on which they feed is unusually succulent. The increase in volume is not attended with a proportionate increase of solids, and thus the percentage of solids in spring and summer milk is less than that in the winter milk unless the cows are particularly well fed during the winter on a generous diet, including large quantities of roots.
Fig. 13.—Cow Stables, Mapletown Farm, Sumner, Washington.
The character of the milk is greatly influenced by the environment in which the cow lives. The stable in which the cow is kept should be clean, well ventilated, and protected against extreme changes in temperature, thus being cooler in the summer than the hot air on the outside and much warmer in the winter. An excellent arrangement of the stables to secure cleanliness and good ventilation is shown in Fig. 13. Cows should be supplied with an abundant quantity of pure water and should not be allowed access to stagnant pools when pasturing in the summer. Every animal giving milk should be examined from time to time by a competent veterinarian to determine, by the injection of serum or otherwise, whether or not the animal is afflicted with tuberculosis. Every animal infected with tuberculosis should be separated from the herd and destroyed. Tuberculosis is an infectious disease and may spread from a single cow to every one in the herd. It is still by some authorities claimed that there is no authentic case of transmission of bovine tuberculosis to the human system. Other authorities hold that such transmission is possible, even if it has not been proven in a particular case. Since experts disagree on this point the same rule is applicable here as in other cases of the same kind, namely, where experts disagree on a point relating to the public health the benefit of the doubt, if any, should be given to the public, and the advice of those experts followed which is the most radical respecting the protection of health from infection of any kind. It would be difficult to prove, for example, in any case of tuberculosis in man that it had been contracted from the sputa of tuberculosed patients, yet because it is possible, in the opinion of many experts, that such infection and transmission of disease can take place, it is the part of wisdom to guard against it.
It is, I think, a statement which will be accepted by all that it is possible in this country to secure and keep a sufficient number of healthy cows to give the milk supply of the nation. Therefore, it is the duty of the state, either by municipal, state, or federal inspection, to eliminate, as far as possible, and, if necessary, at the expense of the state, every diseased animal from the dairy herd. The farmer whose herd becomes infected through no fault of his can justly claim a compensation for the destruction of his animals for the common good. There is, perhaps, no more important point connected with the keeping of sanitary conditions than the proper inspection of the dairy, not only furnishing milk for family use, but especially for sale. It is the plain duty of every municipality and state to prohibit the sale of milk to its citizens from dairies which are not periodically and frequently subjected to the most rigid expert inspection. Such inspection would not only secure the health of the animals but tend directly toward the cleanliness of the dairy. Only by the exercise of unusual care is it possible to keep milk from becoming contaminated.
—Every part of the animal, especially the udders, should be kept scrupulously clean by proper currying and washing. The milk should be collected in vessels with as small an orifice as possible. As soon as drawn the milk should be strained and artificially cooled to a temperature of at least 50 degrees F., if not lower. A convenient apparatus for cooling the milk is shown in Fig. 14. In this condition, without being exposed to infection and being protected from every point by closed vessels, stoppered when necessary by sterilized cotton, the milk is conducted into sterilized bottles and again stoppered with a sterilized cork of some description. The milk is kept cold until delivered to the consumer and by the consumer should be kept cold until used. By following these precautions it is possible to deliver a pure, wholesome, unpasteurized milk in a condition which keeps practically unchanged for even a longer period than twenty-four hours.
Fig. 14.—Apparatus for Cooling Milk.
—Dairies which are inspected either by operation of the law or, voluntarily, by a competent body of medical and scientific experts duly authorized to make such inspection furnish to the market what is known as certified milk. Each bottle of this milk bears the stamp of certification and this stamp may be used from the time of one inspection until a certain date specified on the stamp when the next inspection takes place. The duty of the inspectors is to see that diseased animals are at once removed from the dairy, that the sanitary conditions of the stable are perfect, that the food is abundant and wholesome, that the milking process is conducted according to the principles above outlined, and that the proper precautions are taken to prevent infection during the preparation of the milk for the market. The milk should be examined chemically and bacteriologically at each inspection, or oftener, to see that it is of a standard quality, both in respect of the number and character of the organisms which it contains and of its chemical constituents. Certified milk is, of course, more expensive than non-certified, inasmuch as the dairy is necessarily called upon to bear the expense of inspection. However, the superior quality of such milk and its certain freedom from infection more than offsets the increased price, and makes certified milk the ideal food of a milk character, not only in the family, but especially in the hospitals, orphan asylums and other public institutions. It seems quite certain that in the near future practically all the milk that is sold upon the market of the country will be of a certified quality.
—When milk is heated to a temperature of about 140 to 160 degrees the greater part of the living organisms contained therein are destroyed. At the same time the temperature is not high enough to give to the milk that peculiar taste which it acquires when boiled. Such pasteurized milk, placed in sterilized bottles, stoppered with sterilized stoppers and kept in a cool place, will keep many days and even weeks without apparent deterioration. Physicians and hygienists are quite agreed that pasteurized milk is not so wholesome, especially for children, as certified milk which has not been subjected to a heat sufficiently high to kill the organisms contained therein. The natural ferments of the milk, namely, the enzymes which produce the lactic fermentations, promote rather than interfere with the digestion of the product. The killing of the beneficial organisms of the milk is only justified when there is danger of pathological germs being present. Hence the pasteurization of milk must in this sense be regarded as a substitute for inspection and certification.
There may arise cases where pasteurizing even of certified milk may be desirable, namely, when from necessity it must be kept for a considerable period before use, as on shipboard, and other places inaccessible to a daily supply of fresh milk. Pasteurizing is also justifiable in miscellaneous milk supplies, the origin of which is unknown. It is safer, by far in this case, to pasteurize than take the chance of consuming pathological germs.
—A convenient method of pasteurizing milk is recommended by the Dairy Division of the Department of Agriculture, which is as follows:
[20]—The pasteurization of milk for children, now quite extensively practiced in order to destroy the injurious germs which it may contain, can be satisfactorily accomplished with very simple apparatus. The vessel containing the milk, which may be the bottle from which it is to be used or any other suitable vessel, is placed inside of a larger vessel of metal, which contains water. If a bottle, it is plugged with absorbent cotton, if this is at hand, or in its absence other clean cotton will answer. A small fruit jar loosely covered may be used instead of a bottle. The requirements are simply that the interior vessel shall be raised about half an inch above the bottom of the other, and that the water shall reach nearly or quite as high as the milk. The apparatus is then heated on a range or stove until the water reaches a temperature of 155 degrees Fahrenheit, when it is removed from the heat and kept tightly covered for half an hour. The milk is rapidly cooled without removing it from its containers and kept in a cool place. It may be used any time within twenty-four hours. A temperature of 150 degrees maintained for half an hour is sufficient to destroy any germs likely to be present in the milk, in cold weather, or when it is known that the milk reaches the consumer soon after milking, and it is generally safe to adopt this limit. It is found in practice that raising the temperature to 155 degrees and then allowing the milk to stand in the heated water for half an hour insures the proper temperature for the required time. If the temperature is raised above 155 degrees the taste and quality of the milk will be affected.
[20] By Dr. De Schweinitz.
Inasmuch as the milk furnished to consumers in large cities in summer contains at the time of delivery an immense number of miscellaneous bacteria, this procedure may not fully meet the requirements during hot weather, not only because such milk will not remain sweet for twenty-four hours unless kept in a good refrigerator, but also because the bacteria not destroyed by the heating may at times produce digestive disturbances in the very young. Under such circumstances it is best to keep the bottles in the water until it boils or to use one of the many steamers now on the market. After the bottles have been kept at the boiling point for three to five minutes (or longer if they are large) they should be cooled as promptly as possible and kept in a refrigerator until used.
The simplest plan is to take a tin pail and invert a perforated tin pie-plate in the bottom, or have made for it a removable false bottom perforated with holes and having legs half an inch high to allow circulation of the water. The milk-bottle is set on this false bottom, and sufficient water is put into the pail to reach the level of the surface of the milk in the bottle. A hole may be punched in the cover of the pail, a cork inserted, and a chemical thermometer put through the cork, so that the bulb dips into the water. The temperature can thus be watched without removing the cover. If preferred, an ordinary dairy thermometer[21] may be used and the temperature read from time to time by removing the lid. This is very easily arranged, and is just as satisfactory as the patented apparatus sold for the same purpose. Any other simple method of procedure will give the same result.
[21] Before using the dairy thermometer it is best to have it tested, as it may be unreliable in the upper parts of the scale.
—From the thousands of analyses of American milks that have been made it appears that the average content of fat therein is about 3.90 percent. Of the different breeds of cows the Holsteins produce milk with the least content of fat and the Jerseys with the greatest. It is not unusual to find in the milk of a Jersey cow a content of 6 or 7 percent of fat.
—Human milk differs from milk chiefly in having a much lower content of casein and a higher content of milk sugar. Goat’s milk has a higher content of casein than milk, somewhat higher content of fat, and slightly less sugar. Ewe’s milk is very rich both in protein and fat. Mare’s has a low casein and fat content and is exceptionally rich in sugar. Ass’s milk has less casein and protein than milk but more sugar.
—When milk is allowed to stand for some hours in a cool place or when it is mechanically treated in a separator the fat particles, being of a less specific gravity, are separated, and when they reach a certain degree of consistence they form a product known as cream. The quantity of fat in cream varies according to the method of separation. On standing for a period of about twelve hours in a cool place the separated cream may be removed by skimming and should contain at least 18 percent of milk fat. Under the action of the separator, cream of a much greater content of fat is usually produced, often reaching as much as 30 percent or more. The separation of cream mechanically in a separator is preferable to the method of time separation by gravity alone. The cream secured by the separator is very much fresher, as it can be removed as soon as the milk is drawn and cooled. Its content of butter fat can also be regulated to the desired amount and, in the third place, a more complete separation is secured than by gravity. By the proper manipulation of the separator almost all of the fat in milk is readily removed. Cream should be kept under the same conditions as has been described for sanitary milk. When placed in sterilized containers, properly stoppered and kept cool, fresh cream will keep sweet as long as milk under similar circumstances.
In large dairy industries the separator is practically the only method now employed for securing cream while for farm use the gravity method of standing in a cool place for twelve or twenty-four hours is the commonly practiced method.
Cream is used on the table with fruit and cereal foods and especially in beverages such as tea and coffee. It is also prescribed by physicians for certain diseases and derangement of the digestive organs where the nitrogen content of milk produces irritation and fails of digestion. Cream is not a complete food in the sense that milk is inasmuch as the other constituents of milk are less in proportion as the percentage of fat is increased, yet cream contains at least a part of all the food elements in milk, as, for example, nitrogenous constituent, principally, casein, milk, sugar, and mineral matters.
It must be remembered in this case that the fat is the variable element and as that is increased the proportion of other ingredients, necessarily, is diminished.
The most important use of cream is in the manufacture of butter.
—The composition of cream varies with almost every sample. The standards for cream vary in different states and cities. The national standard requires 18 percent of fat.
—The residue which is left from the removal of cream is known as skimmed milk. Skimmed milk contains the principle part of the nitrogenous constituents of milk, the greater quantity of its sugar and a very large quantity of its mineral matter. It is still a very valuable food product, lacking only the element of fat. When eaten with nuts or other oily food skimmed milk would complete the ration and make a well balanced food. The chief prejudice against skimmed milk is that it has been so often sold for whole milk. When sold and consumed under its own name it is not a fraudulent body and is deserving of a higher place in the dietary than has been ascribed to it. In the large creameries of the country the skimmed milk is usually fed to animals. It is one of the most highly esteemed foods for pigs and poultry, and is largely used for those purposes.
—Naturally the composition of skimmed milk would be that of milk corrected for the abstraction of fat. It contains some little fat when prepared by the gravity method and only a very small portion when separated mechanically. The abstraction of the fat increases the relative proportions of sugar and casein.
—The Wisconsin curd test is conducted as follows: 1. Sterilize milk containers so as to destroy all bacteria in vessels. This step is very important, and can be done by heating cans in boiling water or steam for not less than one-half hour.
2. Place about one pint of milk in covered jar and heat to about 98 degrees F. (Figs. 15 and 16).
3. Add ten drops of standard rennet extract and mix thoroughly with the milk to quickly coagulate.
4. After coagulation, cut curd fine with case knife to facilitate separation of whey; leave curd in whey one-half hour to an hour; then drain off whey at frequent intervals until curd is well matted.
5. Incubate curd mass at 98 to 102 degrees F. by immersing jar in warm water. Keep jars covered to retain odors.
6. After 6 to 9 hours incubation, open jar and observe odor; examine curds by cutting the same with sharp knife and observe texture as to presence of pin holes or gas holes. Observe odor.
7. Very bad milks will betray presence of gas-producing bacteria by the spongy texture of the curd and will have an off flavor.
8. If more than one sample is tested at the same time, dip knife and thermometer in hot water before each time used.
“Normal milk contains practically no organisms but the straight lactic acid bacteria. These germs produce no gas and no bad odors, but purely lactic acid and the curd formed therefrom is such as is represented in Fig. 17.
Fig. 15.—Improvised Wisconsin Curd Test.
C, Can used to hold sample; P, pipette for measuring rennet; K, knife for breaking curd.
Fig. 16.—A, Milk; B, Broken Curd in Whey; C, Matted Curd.
Fig. 17.—Curd from a Good Milk. Large, Irregular Holes Mechanical.
Fig. 18.—Curd from a Tainted Milk. Large, Irregular Holes Mechanical; Small Pinholes Due to Gas.
Fig. 19.—Curd from Foul Milk.
“Milk contaminated by the introduction of dust, dirt, fecal matter, or kept in imperfectly cleaned cans becomes fouled with gas-producing bacteria that break down the milk sugar and so produce gases and usually undesirable odors.... Therefore milks showing the presence of gas or bad odors in any considerable degree are milks that have been more or less polluted with extraneous organisms or carelessly handled, and as a consequence such milks show a type of curd revealed in Figs. 17, 18, and 19.
—The residue left from milk in the process of the making of cheese is known as whey. Whey consists of that portion of milk which is not precipitated by the rennet and which separates when the casein of milk is coagulated and sets in the process of cheese making. The whey contains the principal portion of the water in milk, the most of the milk sugar therein, and small quantities of butter and soluble nitrogenous portions (albumin) and solid particles which remain suspended in the solution. It may, therefore, be properly considered as milk from which the greater part of the nitrogenous portions and fat particles has been separated. The value of whey as a food product consists chiefly in the milk sugar which it contains. It is not very largely used for human food but is valued as a food for young domesticated animals, especially pigs and poultry.
—The whey resulting from the manufacture of cheese contains nearly all the foods of the whole milk with the exception of the casein and fat. It is composed of from 6 to 8 percent of solids consisting chiefly of milk sugar, some albumin, a little fat, and about 0.6 percent of mineral matter.
—Koumiss originated in Asia Minor in the production of a fermented drink from mare’s milk, which is richer in milk sugar than the lactic secretions of most other mammals. By the fermentation of the milk sugar mare’s milk is converted into a fermented beverage containing a small percentage of alcohol. In this country koumiss is made almost exclusively from cow’s milk and by special fermentation at a low temperature. It is a beverage valued especially by convalescents and invalids and frequently is capable of nourishing the body in diseases which affect the digestive organs when other foods fail of assimilation. It is also a cooling and delicious beverage for those in health when properly prepared and stored.
—Koumiss made from cow’s milk with the previous addition of milk or cane sugar to increase the alcoholic content cannot be regarded as a natural product but rather one to which the term “modified” may be applied. The greater part of koumiss made in the United States from cow’s milk is of this modified variety. Cow’s milk contains on an average about 4 or 5 percent of sugar and does not yield a fermented beverage of a sufficient alcoholic content without reducing the actual sugar content of the beverage below the point of palatability. Cane sugar is usually employed as the modifying agent. While modified koumiss cannot be regarded as of equal value with the natural article made from mare’s milk it is a palatable and wholesome beverage when produced and stored under proper conditions. The quantity of alcohol produced in any case is not very great and the change in composition which renders koumiss so easily assimilable in many cases cannot be due alone to the alcohol formed but to the fermentative changes produced by enzymic action which takes place in the other constituents of koumiss, especially casein during the process of fermentation.
Koumiss or kephir, which is the name applied to koumiss made from cow’s milk, is also prepared with the addition of honey, in the place of sugar, and small quantities of wheat flour, not exceeding 20 parts to 1500 parts of other constituents. Koumiss is sometimes artificially fortified by the addition of small quantities of alcohol, but this practice must be regarded as extremely reprehensible. The alcohol of koumiss is incident to its fermentation and should not be increased beyond the normal amount. One of the important points in the making of koumiss is the control of the temperature which, during fermentation, ought not to rise above 50 degrees in order to get the best results. Koumiss may be made in the bottle in which it is kept, in fact, it is best made so, and its fermentation then resembles that of champagne. During the process of fermentation the bottle should be shaken at least once a day in order that the part which coagulates cannot be unevenly distributed throughout the mass. The bottle should be strong enough to resist the pressure produced by the carbon dioxid which is formed and the cork should be securely tied in. As in the case of champagne it is best to place the bottle with the cork down. Before using, the bottle containing the koumiss should be well shaken in order to thoroughly mix the contents which form a creamy, foamy mass extremely palatable, highly nutritious, and valuable not only as a beverage but in many cases of disease and disordered digestion as a food. In fact the value of koumiss for medicinal purposes, that is for medicinal food, is not thoroughly appreciated by the medical profession. This may be due to the fact that the art of making koumiss is not generally known, and while the general principles upon which its manufacture is based have been set forth it requires an expert to make a palatable and useful article (“British Dairy Farming” by Jas. Long). It is worthy of suggestion now that the use of horses for draft purposes has practically been superseded by the automobile and the trolley that the production of real koumiss from mare’s milk might become a very useful field of industry in the United States. It is perfectly certain that the genuine article must possess properties which are not wholly found in the imitations of koumiss which are so common in this country. It is well understood by physicians that a natural product produced from natural material is always superior in character both as a food and medicine to the synthetic or artificial product. Whenever, therefore, a fermented beverage produced from natural sources is contaminated by artificial products the resulting compound is not so useful nor digestible. For instance, wine which is made partially from sugar and beer made partially from dextrose, although they may be healthful and wholesome beverages, are inferior in quality and character to the real product made from grape juice or barley malt.
—The residue left in the churn in the manufacture of butter is termed buttermilk. There are two distinct varieties of buttermilk, namely, that resulting from the churning of unsoured cream and that remaining from the churning of soured and ripened cream. The first kind of buttermilk does not differ in its characteristic essentials from skimmed milk and therefore is not considered here. The second class of buttermilk is far more common and is a beverage of pleasing acid taste. When made from properly ripened cream it is wholesome and delicious, especially in summer time. Its composition is that of cream subjected to enzymic action during the ripening process by which an agreeable degree of acidity is produced due to lactic acid, together with the incidental changes which take place in the composition of other parts of the liquid due to enzymic action. Buttermilk also usually contains small particles of butter itself which escape aggregation during the final process of churning. In well prepared buttermilk, however, these particles of butter are not very numerous and they add nothing to the palatability, although they do add something to the nutritive properties of the beverage. The buttermilk represents that portion of milk which is one of the chief constituents of cream as far as bulk is concerned, freed practically from its butter fat. It does not differ greatly, therefore, in its chemical properties from skimmed milk, although there is a slight difference in the relative percentages of the milk solids in cream as compared with the same constituents in whole milk. The composition of buttermilk is shown in the following table:
COMPOSITION OF BUTTERMILK.
| From Sweet Cream. |
From Sour Cream. |
|
|---|---|---|
| Percent. | Percent. | |
| Water, | 89.74 | 90.93 |
| Fat, | 1.21 | 0.31 |
| Milk sugar, | 4.98 | 4.58 |
| Protein, | 3.28 | 3.37 |
| Ash, | 0.79 | 0.81 |
| Acidity, | ... | 0.80 |
—Bonnyclabber is a term applied to milk which has become soured by lactic fermentation, producing a gelatinous coagulation of casein which is sufficiently firm at times to prevent the liquid from being poured. Clabber may be regarded as a natural cheese curd except that the fat is chiefly on top. It is a beverage or food of a very agreeable taste to most persons and is often eaten with sugar. In the summer it is often formed during hot murky weather, especially of that character which produces thunder storms. For this reason it is a common supposition that thunder or lightning sours milk. The thunder and lightning, however, have nothing to do with this process. The condition of the atmosphere which produces an environment favorable to electrical disturbances of this kind also favors in the highest degree the growth of the organisms which produce the lactic ferments. Hence thunder storms and the rapid souring of milk are frequently coincident leading to the popular impression as above mentioned. Inasmuch as the souring of milk usually takes place after the cream has risen the composition of clabber is practically that of skimmed milk modified by the lactic fermentation which has taken place.
When cream, especially cream in which incipient lactic fermentation has been set up, is subjected to agitation in a churn under proper conditions of temperature the particles of butter therein contained are collected into masses so that the butter can be separated from the residual liquid. This process is technically called churning. The domestic churn in its simplest form is perhaps well known to almost everyone, especially those who have lived in the country. In the domestic manufacture of butter the cream is collected and set aside until sour, that is, until lactic fermentation has set up. When this is sufficiently advanced the cream is placed in a churn, the simplest form of which is a wooden, cylindrical vessel of appropriate size, being much longer than its horizontal diameter. The churn is provided with a dasher, namely a perforated wooden disk with a handle which passes through a hole in the cover. When the churn is charged the butter is produced by agitation with the dasher. In winter time warm water is added to the mixture in order to raise the temperature to the proper gathering point of butter, namely 65 to 70 degrees F. For the same reason cold water is added in the summer time. The art of the dairy maid is shown in the proper regulation of the temperature to secure the best results. When the cream is properly ripened and the temperature is suitable the gathering of butter will be accomplished in from twelve to thirty minutes. In unfavorable conditions the duration of churning may be for a much longer period.
Fig. 20.—Power Churn Ready for Use.—(Courtesy of the Bureau of Animal Industry.)
In dairies and large establishments churning is accomplished by machinery with very different mechanical appliances, but the principle which underlies the process is the same as those outlined above. The accompanying figures illustrate the process of churning by mechanical means in a modern dairy (Figs. 20 and 21).
Fig. 21.—Power Churn, Open.—(Courtesy of the Bureau of Animal Industry.)
—The crude butter secured by churning is subjected to washing and seasoning processes in order to prepare it for the market. The washing or working of butter is accomplished by means of water. The object of this “working” is to separate from the crude butter as much of the curd and other non-fatty constituents of the cream as can be conveniently accomplished. The removal of these mechanical particles not only makes a butter of a higher grade but also one of better keeping qualities. The working of butter also has much to do with its grain or texture, which is one of the characters of butter to which great attention must be paid. The best grade of butter and that which brings the highest price in the market is that which receives no treatment other than that of the washing and working process to which attention has been called. This kind of butter is known as natural or unsalted or uncolored butter, that is, a fresh, sweet product of an agreeable aroma, palatable, of fine texture and grain, and is the best product of its kind for human consumption. It also brings the highest price on the market and, by reason of its method of preparation, the consumer can usually be assured that it is fresh in character.
—In the United States, especially, consumers of butter generally require that it shall be salted. For this purpose fine grades of dairy salt are used as free as possible from impurities and consisting of fine particles or crystals which rapidly dissolve in the residual moisture of butter. This promotes a uniform distribution of the salt in the form of brine throughout the mass of butter. The existence in butter of undissolved particles of salt is highly prejudicial to its taste and character. The quantity of salt used in butter is determined by the taste of the consumer. The more salt the butter contains the less value it is as butter and hence the quantity should be limited to the smallest possible amount demanded by the consumer’s taste. Often butters are found in commerce which are so full of salt as to be wholly unpalatable and there is a tendency on the part of the greedy manufacturer to add excessive quantities of salt because it is very much cheaper than the butter itself and thus he hopes to add to the profit of the industry. On the contrary this practice usually results in loss, since such highly salted butter naturally brings the lowest price. The amount of salt which is used in butter should not exceed two percent.
It is a common supposition that salt in butter is a preservative. This is true when used in large quantities, that is, in quantities which render the butter somewhat unpalatable. The very small quantity of salt used purely for condimental purposes cannot be regarded as aiding in any material way the preservation of the product.
—Unfortunately the practice of artificially coloring butter is very prevalent in the United States. Practically all the butter found upon the market, even in the spring and summer, is more or less artificially colored, often with coal tar (anilin) dyes which, to say the least harm of them possible, are open to suspicion in respect of wholesomeness. The practice of coloring butter produced in winter may be regarded as universal, though none the less reprehensible on that account. The object of coloring butter is, undoubtedly, to make it appear in the eyes of the consumer better than it really is, and to this extent can only be regarded as an attempt to deceive. If cows are properly fed during the winter months with wholesome, nutritious food to which a small proportion of roots such as carrots or ruta bagas are added or with yellow maize and clover hay, even in winter time the butter produced will have an attractive light amber tint which appeals strongly to the æsthetic sense of the consumer. The natural tint of butter is as much more attractive than the artificial as any natural color is superior to the artificial. There is the same difference between the natural tint of butter and the artificial as there is between the natural rose of the cheek and its painted substitute. It is claimed, and perhaps justly, that the use of certain vegetable colors, such as annotto, does not introduce any unwholesome substance into the product. Admitting this, we must next ask whether it deceives the consumer. If so, it is difficult to understand upon what ethical principal any plea for the artificial coloring of butter can rest. If it is admitted that there is no valid reason why butter should be colored other than the artificial coloring of foods in general, which is a practice so reprehensible that it is almost universally denounced, its practice cannot be easily defended. The dairymen of our country are honest and honorable and evidently do not clearly see the false position in which the practice of coloring butter puts them. When the dairymen of our country understand that the naturally colored products will bring the highest price on the market and appeal more strongly to the confidence of the consumer it is believed the artificial coloring in butter will be relegated to the scrap pile of useless processes. It cannot be claimed in any sense that coloring of butter artificially ever adds anything to its value as a nutritive substance.
One of the claims for justifying the coloring of butter is that it distinguishes it from oleomargarine. This, however, is not the case since, under the law, oleomargarine may be colored upon the payment of a tax of ten cents per pound. The consumer has at his disposition a complete protection against fraud in the use of oleomargarine by the operation of state and federal laws, irrespective of the tint of the product. Oleomargarine and butter are distinguished from each other by their natural colors and also by their chemical and physical properties and, therefore, there can be no justification for the coloring of butter on the plea that it distinguishes it from oleomargarine. Thus, from every point of view it is evident that the artificial coloring of butter is undesirable. It interferes with the right of the consumer, who should know the exact character of the product he buys, and it stands in the way of the prosperity of the manufacturer by keeping upon the market a cheaper product which tends to decrease the price even of that of better quality.
—According to the standard established by Congress butter must contain more than 16 percent water and not less than 82.5 butter fat.
—The law of Congress which controls the manufacture of renovated butter is executed jointly by the Treasury and Agricultural Departments. The quantity of renovated butter produced during the year ending June 30, 1905, was 60,290,421 pounds.
—The quantity of adulterated butter which was produced under the authority of the Act regulating the manufacture of oleomargarine and butter and on which is laid a tax of 10 cents per pound during the fiscal year ending June 30, 1905, was 3,671 pounds. These data show that the tax of 10 cents per pound laid upon adulterated butter has practically destroyed the manufacture of that article. Normal butter has from 12 to 14 percent of water. It is sometimes rechurned with water to raise the water content to 16 percent. Such a practice results in adulteration whether the content of water exceeds 16 percent or not.
—The character of butter is very easily affected by the nature of the food consumed by the cow. Butter has the faculty of absorbing very readily odors of all kinds. Foods, therefore, which have characteristic odors impart them to the butter. A most striking instance of this is in the eating of wild garlic. In this case both the milk and the butter are affected to such a degree as to be in many cases unpalatable. Hence foods or substances in foods which are aromatic or odoriferous are likely to impart their peculiar odor to the milk, cream, and butter. Of all the constituents of milk the fat appears to have the highest faculty of absorbing these objectionable odors. Therefore, the feeding of distillery slops is also apt to impart an unpleasant odor to milk and butter, whereas if these slops be dried and their volatile aromatic principle expelled little discomfort is experienced in their use. The physical characteristics of butter are also changed in a marked degree by the character of the food. Butter fat, as has already been indicated, is distinguished from other animal fats by its content of soluble and volatile acids of which butyric is the chief. There are certain kinds of foods which decrease or tend to decrease the content of butyric acid in butter.
—The character of the food also has a marked influence upon the melting point of butter. The author showed many years ago that the use of cottonseed meal as food for cows tends to raise the melting point of butter. This was regarded as an index of some value for the southern portion of the country, where a high temperature obtains over a period of six or seven months of the year. If the melting point of butter, which when normal is about 33 degrees C. (91° F.), could be increased to 35 or 36 degrees C. (95° F.), it would be of immense advantage in these warm climates and, in fact, in all parts of the country during the months of July, August, and September. There is no apparent tendency to increase the melting point of butter by feeding other oil cakes.
—Experience has shown that when cows are fed cottonseed meal or its products the quality of cottonseed oil which responds to the color test known as the Halphen test, namely, the production of a red color with carbon disulfid and amyl alcohol, is transmitted also to the butter. In some cases this reaction is extremely faint while in others it is displayed with an intensity which is claimed by some to be equal to that of the admixture of 5 percent of cottonseed oil with the butter. The use of cottonseed meal, on the contrary, does not seem to notably affect either the content of volatile acid in the butter nor its refractometer reading. (Experimental Station Record, Volume 25, Page 716.)
Oleomargarine is the name applied to any fatty substance which is prepared to be used in the same manner as butter. Oleomargarine is defined by Act of Congress as follows:
An Act defining butter, also imposing a tax upon and regulating the manufacture, sale, importation, and exportation of oleomargarine. (Approved August 2, 1886.)
“That for the purposes of this act certain manufactured substances, certain extracts, and certain mixtures and compounds, including such mixtures and compounds with butter, shall be known and designated as “oleomargarine,” namely: All substances heretofore known as oleomargarine, oleo, oleomargarine oil, butterine, lardine, suine, and neutral; all mixtures and compounds of oleomargarine, oleo, oleomargarine oil, butterine, lardine, suine, and neutral; all lard extracts and tallow extracts; and all mixtures and compounds of tallow, beef fat, suet, lard, lard oil, vegetable oil, annotto, and other coloring matter, intestinal fat, and offal fat made in imitation or semblance of butter, or, when so made, calculated or intended to be sold as butter or for butter.”
The manufacture of oleomargarine can only take place in the United States under the supervision of officials of the Internal Revenue. All oleomargarine which is artificially colored a yellow or yellowish tint in semblance of natural butter pays an internal revenue tax of 10 cents per pound. Oleomargarine uncolored pays a revenue tax of one-fourth cent per pound. Oleomargarine when made under proper sanitary conditions from sanitary raw materials is a wholesome and nutritious article of diet and usually can be sold at a smaller price than butter. It is especially a food product which commends itself to those who are under the necessity of practising strict economy in the cost of food in the family. The principal objection, and in fact the only valid objection, to its use is found in the frauds which have been committed in its manufacture and sale. There has been a constant disposition on the part of dishonest manufacturers and dealers, since the time when oleomargarine became a commercial commodity, to sell it as butter. Although the penalties of national and state laws are very severe in this respect the practice is continued. The opportunity for gain is so great that the cupidity of the manufacturer overcomes his fear of punishment and disgrace. With a more rigid national and state inspection, it is reasonable to hope that this fraudulent use of oleomargarine can be avoided and the pure, unadulterated article under its own name be supplied to those who prefer it either on account of its properties or its price.
—Neutral Lard.—One of the principal basic components of oleomargarine is neutral lard or lard stearin, the properties of which have already been described. Beef fat stearin is another basic ingredient of oleomargarine and is the stearin derived from tallow or tallow itself. Beef fat has a higher melting point than lard and beef fat stearin a still higher melting point than the tallow. Hence it forms an ideal ingredient with which to mix the oily components which enter so largely into the manufacture of oleomargarine. The beef fat or beef fat stearin is easily distinguished by means of the microscope. It forms beautiful radiated fan-like crystals, the characteristic appearance of which is shown in Fig. 9, page 67.
—These are also important ingredients of oleomargarine affording the oily or more liquid constituents which, when mixed with the lard and stearin above mentioned, form a compound the melting point of which is slightly above that of butter and sufficient to maintain it in an unmelted state even in warm weather. The quantities in which these different ingredients are used vary greatly in different manufacturing establishments and depend largely upon the location where the oleomargarine is to be used. When manufactured for tropical or subtropical regions larger quantities of stearin are employed than when used in temperate zones or for winter consumption, in which case larger quantities of cottonseed oil and cottonseed oil stearin are employed with the mixture. After the fats are mixed it is usually the practice to churn them with milk in order to give a flavor of butter to the product. In some cases the yolk of eggs is mixed with oleomargarine, as it is claimed that they impart thereto a firmer and more homogeneous structure which renders the mass better, especially for cooking purposes. All the ingredients which are used in the manufacture of oleomargarine are made known and recorded in the books of the Commissioner of Internal Revenue and thus it is a product which it may be said is strictly under government supervision.
—The fat is taken from the cattle in the process of slaughtering, and after thorough washing is placed in a bath of clean, cold water, and surrounded with ice, where it is allowed to remain until all animal heat has been removed. It is then cut into small pieces by machinery and cooked at a temperature of about 150 degrees until the fat, in liquid form, has separated from the fibrine or tissue, then settled until it is perfectly clear. Then it is drawn into graining vats and allowed to stand a day, when it is ready for the presses. The pressing extracts the stearin, leaving the remaining product, which is commercially known as oleo oil, which, when churned with cream or milk or both and with or without a proportion of creamery butter, the whole being properly salted, gives the well-known food-product, oleomargarine.
—Since the coloring of oleomargarine is permitted upon the payment of a tax, oleomargarine which is colored cannot be said to be adulterated when the tax has been paid, although if coloring were not a legalized operation it would be an adulteration. Yellow oleomargarine is an imitation of natural butter and its manufacture should be prohibited unless the product is marked “imitation.” The character of the coloring materials used is not prescribed by the Commissioner of Internal Revenue but as a rule the coal tar dyes are preferred in the coloring of oleomargarine to the vegetable coloring matter such as annotto and saffron. The remarks which have been made in connection with the use of poisonous materials in other products apply to oleomargarine.
—An adulteration which has been practiced in this country is the admixture of preserved egg yolks. Usually these yolks are secured in China, broken, and placed in vessels and preserved with borax or boric acid or salt. These eggs are generally collected during the early spring and summer months and are not sent to the United States until the fall or winter. The importation of such articles is now prohibited under the food laws of the country so that the adulterations with the imported article is no longer to be feared. It is possible to preserve domestic eggs in the same way, and the use of them in this manner is regarded as an adulteration, since such preserved egg products cannot be regarded as suitable for human food.
—Fortunately preservatives are not used to any extent in the manufacture of oleomargarine when intended for domestic use. The most suitable preservative in such a case as this would be borax or boric acid. It is not believed that these preservatives are used to any extent when the product is intended for domestic consumption. Whether or not preservatives are used in the product sent abroad I am unable to say.
—According to the report of the Commissioner of Internal Revenue the quantity of oleomargarine taxed at 10 cents a pound produced in the United States for the fiscal year ending June 30, 1905, was 5,584,684 pounds, and for 1906, 4,888,968 pounds. The quantity produced in 1906 taxed at one-fourth cent a pound was 50,545,914 pounds.
COMPOSITION OF OLEOMARGARINE.
| Specific Gravity at 40°C. |
Water. | Insoluble Acid. |
Sol. Acid by Washing Out. |
Sol. Acid by Distillation. |
Salt. | Albuminoids. |
|---|---|---|---|---|---|---|
| .90490 | 9.34 | 93.59 | 0.12 | 0.25 | 3.64 | 0.35 |
From the above data it is seen that the objections to the use of oleomargarine are more on the grounds of fraud and deception than in regard to nutritive and dietetic value. The components used in the manufacture of oleomargarine, when properly made, are all wholesome and digestible materials such as are consumed in eating various food products. It does not appear, therefore, that any valid objection can be made against the use of oleomargarine from a physiological or hygienic standpoint.
—The preparation of cheese is one of the oldest of the technical processes. It appears that it was known during the time of King David, at least a thousand years before Christ, and the Greeks were acquainted with it before the writings of Homer. Aristotoles and Hypocrates describe the curdling of milk which at that time appears to have been accomplished by the use of the juice of the fig. The use of cheese was very common in Rome in the earlier historical days but the most of it was imported from the North. Cæsar speaks of the preparation of cheese among the German tribes. Cheese must, therefore, be regarded as one of the very oldest forms of prepared food used by man. It probably is almost, if not quite, as old as wine. These historical facts are interesting in showing how from the earliest times man has made use of the natural ferments to prepare food from the raw material. Attention must be called in this connection to the fact that many people claim that such foods as these are not natural foods but wholly artificial. The fallacy of such a claim is not difficult to show. An artificial food is one which is prepared out of materials which, themselves, are not edible food products or, at least, are not digestible or of a character which does not naturally occur by ordinary processes. Artificial foods, therefore, are purely synthetic, that is, made up from the elemental substances, or they are mixtures or compounds. On the contrary a food like cheese or wine is not a mixture or compound but a natural product from materials which themselves are food products. Milk is the raw material of cheese as the must of the grape is of wine. Both milk and must are rich and nutritious foods. The changes which each undergoes are in many respects the same. The must of wine undergoes an alcoholic fermentation and the milk sugar of cheese is subjected to a lactic fermentation and its casein to a proteolytic change which materially alters its character.
Cheese products are a very important part of food materials of the dairy. The term cheese is applied to the solid product produced from milk by coagulation of the casein with rennet or lactic acid and subjecting the solid product thus produced to a process of fermentation and ripening by the addition of appropriate seed material, seasoning, and storage at convenient temperature for varying periods of time. In the precipitation of the casein of milk the fat particles become mechanically entangled and form a part of the precipitate. There is a certain quantity of other milk constituents incorporated in the form of water, milk sugar, and mineral matter in the precipitated mass. The greater part of the other bodies which the milk contains, consisting of the milk sugar and a considerable portion of the soluble mineral matter, are separated in the form of whey. The composition of fresh cheese is that of that part of the milk which is precipitated and which is entangled mechanically in the precipitated matter. The ripened cheese is changed in its chemical constituents mostly as the result of fermentative action upon its nitrogenous constituents, that is, the casein, albumin, etc., contained therein. The ferments tend to change the casein into a more soluble form of protein, while at the same time they develop a flavor and aroma in a way agreeable to the nostril and palate. Various forms of moulds and other organisms grow on and in cheeses which influence their palatability and character. The final product of the ripened cheese varies not only with the nature of the original material as determined by the milk itself but with the character of the preparation and the nature of the organisms and ferments which are active during the ripening period, and also with the time and temperature of storage.
—It is not necessary and perhaps it would be impossible to attempt an enumeration of all the various kinds of cheese which are offered on the market. The first classification of cheese depends upon the character of the milk used. The term “cheese” in this country naturally refers to a product made from cow’s milk since that is the principal milk used in the United States for cheese making. The term is used in this manual in that sense and when there is no qualifying word employed it is always understood that the product in question is made from the cow’s milk. This implies that the milk is at least a standard milk, that is, a whole milk, unskimmed and containing not less than 3.25 percent of butter fat. According to the definition fixed by the Congress of the United States the term cheese is applied not only to this product but also to one containing a larger percentage of fat than this. The term cheese applies both to cheese made from milk and cheese made partially from milk and partially from cream. The term “full cream cheese” is also often used in the trade but is likely to be misleading and deceptive. The real significance of the term full cream cheese is that it is made of whole milk or milk unskimmed which contains its full complement of cream. The term “cream cheese” is also often used to indicate a cheese made partially of milk and cream. It is evident that the term cream cheese in this sense is misleading, since it can be properly applied only to a cheese made from cream alone. Such cheeses are made but, inasmuch as cream must have not less than 18 percent of fat in order to be called cream according to the United States standard, the cheeses made from such a source are too oily and fatty for ordinary consumption.
—Goat’s milk is also frequently used in making cheese. It is extensively employed in France and Switzerland for cheese making and also in other parts of Europe, and to a limited extent in this country. Some of the varieties of cheese which are most highly prized are made from goat’s milk, such as Roquefort.
—The most common form of adulteration or sophistication of cheese is the misbranding thereof in respect of the country where made or in respect of character. This is a form of deception which has long been established in the trade and one which cannot be condoned or excused. There are certain varieties of cheese whose names should be respected and in fact, in the case of all varieties that have an established character and reputation, their name should not be applied to other articles made in imitation thereof. In this country there is a national law which prohibits the marking of a food or dairy product falsely as to the state or territory where made. For instance, a cheese made in Ohio cannot be marked New York cheese and peaches grown in Delaware cannot be marked California peaches, maple sirup made in Indiana cannot be labeled Vermont maple sirup, etc. The ethical principle underlying this law is one which will meet the approbation of every well meaning man and therefore the extending of this principle to other forms of misbranding is an easy step. If it is a violation of the law to mark a cheese made in Ohio as made in New York it is certainly a violation of the ethical principle underlying that law to name a cheese made in Connecticut Cammerbert. Unhappily, however, there are cheeses made in the United States to which foreign names are given, the universal excuse being that they are cheeses of the same type. In many cases this excuse is not a valid one and in no case is it an accepted one. To name a cheese made from cow’s milk the same as that made from ewe’s milk is a distinct misbranding in every sense of the term. There should be no difficulty in established varieties of cheese made in this country having names which are not deceptive and not intended to mislead the consumer as to the state, territory, or country where made. In one sense all cheese may be said to be of the same type, but because the taste and odor of a cheese made in the United States imitates to some extent that of a cheese made in France is no excuse for giving the French name to the American product. A further illustration of this principle is found in the following: The term Roquefort, for instance, is not properly applied to any cheese product except that which is made at or in the vicinity of Roquefort. In no other part of France can cheese be made bearing the name of Roquefort. The use of the term Roquefort, therefore, in any way upon American cheese is a misbranding and an attempt to deceive which usually is successful. There is not so great an objection to the term Swiss cheese as to Roquefort, but there is the same kind of an objection. The cheese which bears the name of Schweitzer-Käse is very extensively manufactured in Germany and sold under that name. A similar cheese is also extensively made in this country and sold under the name of Schweitzer-Käse. In this case there is no particular location or place which originated the name and has the sole right to use the name Swiss cheese. It is the name of a whole country and not of a location, and yet it is evident that Swiss cheese properly can only be made in Switzerland and not in Germany or in the United States. Any hard, tough cheese in which a large number of holes is found and which on cutting makes a flexible, semi-leathery slice has to a certain extent the appearance and perhaps the taste and flavor of genuine Swiss cheese.
It should not be difficult to find a market for all good cheese made in this country, under appropriate American names indicating their origin. If the term Swiss cheese is at all allowable on a package it should be placed as a minor part of the label and with the statement that it is of that type. Even this transgression is perhaps difficult of excuse.
—Next to misbranding and misnaming of cheeses, perhaps the most common adulteration is that of artificial coloring. The public taste has been led in the matter of cheeses, especially of American origin, to look for a deep yellow color. This is also associated with the idea of the use of a large quantity of rich, naturally yellow-colored cream. The addition of an artificial color to a cheese never adds anything to its value, and to the really æsthetic eye detracts much from its appearance. The presence of this rich artificial tint is calculated in many instances to excite a suspicion in regard to the character of the cheese and thus interferes with its proper gustation. There is another more serious objection than the one just mentioned, namely, that it is possible from skimmed milk to make a highly colored cheese which would appear to the consumer to be made of whole milk or of milk and cream, and thus a deliberate deception is perpetrated. The consumer of cheese should demand that artificial coloring of all kinds be omitted from cheese products.
Moreover, these colors may of themselves be deleterious in character and there is no restriction, so far as I know, at this time in the United States to prevent a manufacturer, if he so desires or through his ignorance of the use of coloring materials of a poisonous character, from using any amount.[22] The coal tar dyes are cheaper and produce faster and more natural looking tints than the vegetable colors such as annotto and saffron, and hence, unless they are prohibited by law, they are almost universally employed. All of these dyes in a concentrated form are highly poisonous and injurious and several instances are on record of death, especially in the case of young children, from eating concentrated colors. The fact that a poison of this kind is diluted by the cheese is no excuse for its use. The only protection which the consumer has, which is reliable in all cases, is the prohibition of coloring matter in cheese.