THE STORY OF MILK TEXT

The amount of heat required to raise the temperature of one kilogram of water 1° C., or one pound 4° F., is called a calorie. By extensive feeding experiments the caloric value of the various nutrient groups has been estimated as follows: Protein at 1820 calories per pound[9] Fats at 4040 calories per pound Carbohydrates at 1820 calories per pound Measured by this rule the fuel value of: Whole milk is 310 calories per pound Skim milk is 160 calories per pound Full cream 1885 calories per cheese is pound Butter is 3410 calories per pound Compared with other food, milk, although not suited to act as the sole food of adults, is one of the best and cheapest articles of diet, and should be much more extensively used. The following table, compiled by specialists of the U. S. Department of Agriculture, shows the quantities of various foods needed to supply as much protein or energy as 1 quart of milk: ┌────────────────────────────┬────────────────────────────┐ │ Protein │ Energy │ ├────────────────────────────┼────────────────────────────┤ │1 quart of milk is equal to—│1 quart of milk is equal to—│ │ 7 ounces of sirloin steak │ 11.3 ounces of sirloin │ │ 6 ounces of round steak │ steak │ │ 4.3 eggs │ 14.9 ounces of round steak│ │ 8.6 ounces of fowl │ 9 eggs │ │ │ 14.5 ounces of fowl │ └────────────────────────────┴────────────────────────────┘ Another method of comparison is shown by the table below, in which the relative value of certain foods as economical sources of protein is given: ┌────────────────┬──────────────────┬──────────────────┐ │ │ Is as cheap as │ │ │ Milk at— │sirloin steak at— │ Or eggs at— │ ├────────────────┼──────────────────┼──────────────────┤ │7 cents a quart │16.3 cents a pound│17.6 cents a dozen│ │8 cents a quart │18.6 cents a pound│20.1 cents a dozen│ │9 cents a quart │21.0 cents a pound│22.6 cents a dozen│ │10 cents a quart│23.3 cents a pound│25.1 cents a dozen│ │12 cents a quart│27.9 cents a pound│30.2 cents a dozen│ │15 cents a quart│34.9 cents a pound│37.7 cents a dozen│ └────────────────┴──────────────────┴──────────────────┘ According to this table, if milk is selling at 10 cents a quart, sirloin steak must sell as low as 23.3 cents a pound, and eggs at 25.1 cents a dozen to supply protein at equal cost. _To Supply Energy at Equal Cost_ ┌────────────────┬──────────────────┬──────────────────┐ │ │ Sirloin steak │ │ │When milk is— │ must not │ And eggs not │ │ │ be more than— │ more than— │ ├────────────────┼──────────────────┼──────────────────┤ │7 cents a quart │9.9 cents a pound │ 9.3 cents a dozen│ │8 cents a quart │11.3 cents a pound│10.6 cents a dozen│ │9 cents a quart │12.8 cents a pound│11.9 cents a dozen│ │10 cents a quart│14.2 cents a pound│13.2 cents a dozen│ │12 cents a quart│17.0 cents a pound│15.9 cents a dozen│ │15 cents a quart│21.3 cents a pound│19.8 cents a dozen│ └────────────────┴──────────────────┴──────────────────┘ =Fallacy of Theoretical Valuation.=—While the contents of protein and the ratio between digestible protein and fats and carbohydrates on one hand, and the fuel or energy value on the other, have long been the only recognized measures for food values, they are admittedly quite inadequate and insufficient and although they are a great help when used with discrimination in making up food rations, they are often abused by persons who do not take their fallacies into consideration. [Illustration: Dr. E. V. McCollum ] “=Something Unknown.=”—Recent investigations by Dr. F. G. Hopkins, of Cambridge, England, and Dr. E. V. McCollum, formerly of Wisconsin, now of the Johns Hopkins University, have proven conclusively that one food ingredient cannot always be substituted for another with impunity even though the most searching chemical analysis shows them both alike in contents and digestibility. There is “Something Unknown” in certain foods—“Vitamines” some call it—essential especially in promoting the growth of the young, which our present knowledge of chemistry cannot explain. In Bulletin No. 17 of the Wisconsin Experiment Station experiments with the feeding of rats are described which show how butter-fat could not be replaced in the ration by vegetable fats of apparently the same composition and digestibility without disastrous results, and similar conditions have been found in regard to other foodstuffs, proteins as well as fats. The yolk of eggs and butter-fat contain this unknown something which is absolutely essential for the growth of the child and which is missing in most substitutes, especially in lard and vegetable fats. [Illustration: The rat on the left got five per cent of cottonseed oil and the one on the right got instead one and a half per cent of butter-fat, otherwise their rations were alike. These results are typical for any ration made up of purified foodstuffs with butter-fat in them as compared with any fat of plant origin. The plant fats lack an unknown something without which growth cannot proceed. ] The above illustration is from the work of McCollum and Davis at the Wisconsin Experiment Station. Realizing the fallacy of the old rules for making up rations for the feeding of farm animals, Professor Evvard of Iowa is trying the _reliability_ of the _instincts_ of animals as a guide to the proper selection of the most favorable combinations and proportions of food ingredients.[10] We mention these experiments as a warning against placing too great reliance on the caloric theory or the relation of nutrients in making up food rations. We have yet much to learn and the good housewife trying to cook according to scientific rules will do well not to neglect the palatability of the food, but to watch the “instinct” which causes the child or the adult to reject or approve of, and enjoy, the food, which in most cases is a better guide than calories or protein contents, or the ration between the various groups of nutrients. CARE OF MILK IN THE HOME If received fresh and warm from the cow, milk should at once be strained through absorbent cotton or several thicknesses of cheese-cloth into wide-mouthed bottles or glass jars and placed in running water or ice water to cool as quickly as possible. If obtained from the milkman it may be left in the bottle in which it is received. The practice of delivering milk “loose,” dipping it from the wagon, should not be permitted, and is fast being abolished. Public safety demands that it should be bottled on the farm or in the creamery or milk station under sanitary conditions. =Keep the Milk Cool.=—If the milk when delivered at the house is not cold enough to keep sweet as long as desired, it should, we repeat, be placed in ice water or cold running water until thoroughly cooled. Even if the air is cold, in the ice box, for instance, the milk cannot be cooled quickly enough without water. After it has been cooled in water it may be put in the ice box. In most ice boxes the temperature is allowed to rise higher than is generally supposed, and it is better to keep the milk bottle next to the ice than in the food compartments. [Illustration: A clean ice box ] Milk and cream easily absorb flavors from the air and should not be kept in open vessels next to other food. Any housekeeper knows how quickly milk or cream will be tainted by standing in the same compartment with onions or muskmelons; if the bottle is not covered, milk may also be contaminated by other less noticeable but more harmful vapors from nearby products. Let the milkman furnish you with some extra milk bottle caps, or cover your milk bottle with an inverted tumbler. As has been shown in previous chapters, milk is a favorable soil for all sorts of germs and bacteria to grow in. It must therefore be kept from contamination with the utmost care, and everything that comes in contact with it must be scrupulously clean. =Top-Milk.=—When the milk has been standing at rest three or four hours, the top-milk will be considerably richer than the rest. If such rich milk is wanted for any particular purpose it may be poured off, to be eaten with cereals, berries, etc. In twelve hours most of the cream will rise and may be skimmed off, although thirty-six or even forty-eight hours may be required to get all that can be obtained by setting. The half-skimmed milk left when the top-milk has been removed after 3 to 6 hours’ setting will still contain 2% or more of butter-fat and is very good for drinking; even the skim milk from which the cream has been taken after 12 hours’ setting is still an excellent beverage, provided it is sweet. Perfectly skimmed, almost entirely fatless, milk may be used in various ways in cooking, to make up for lack of protein in many other food products. But care must be taken that it is pure and sweet, or rather, its condition, sweet or sour, must be under the perfect control of the housekeeper. If a sample of milk will stand scalding or even boiling without curdling, it is usually fresh and in good condition for any use. On the other hand, if it curdles by scalding, it is beyond control and it may or may not make good sour milk, depending on the bacteria working in it. MILK FOR INFANTS [Illustration] Comparing cow’s milk with mother’s milk, it will be seen that the latter contains less protein, about the same percentage of fat and more carbohydrates than the former. A comparison may be made from the following table of average composition in round figures: ──────────────┬───────┬───────┬───────┬───────┬───────┬───────┬─────── │ │ │ │ │ │ │ Fuel │ Water │ Total │Protein│ Fat │ Milk- │Mineral│ value │ │solids │ │ │ sugar │matters│per lb. ──────────────┼───────┼───────┼───────┼───────┼───────┼───────┼─────── │ Per │ Per │ Per │ Per │ Per │ Per │Calories │ cent │ cent │ cent │ cent │ cent │ cent │ ──────────────┼───────┼───────┼───────┼───────┼───────┼───────┼─────── Mother’s Milk │ 87 │ 13 │ 2 │ 4 │ 6.5 │ 0.5 │ 316 ──────────────┼───────┼───────┼───────┼───────┼───────┼───────┼─────── Cow’s Milk │ 87 │ 13 │ 3.25 │ 4 │ 5 │ 0.75 │ 312 ──────────────┴───────┴───────┴───────┴───────┴───────┴───────┴─────── =Modifying Milk.=—Undiluted cow’s milk is too rich in protein and in salts for infants and, when fed without modification, must be diluted with an equal amount of water during the first two or three months. Such dilution, however, also reduces the percentage of fat, which should remain the same, and of carbohydrates, which should be increased. In order to modify or “humanize” cow’s milk so as to make its composition nearly the same as that of mother’s milk, simple dilution with water is therefore not sufficient. There are, however, various other methods which may be used to advantage. For instance, top-milk from a bottle of fresh milk which has stood 4 or 6 hours in ice water will contain 6 to 8% of fat. By diluting this with an equal part of water, the percentage of protein, fat and mineral matter will be about right, and sugar, either cane-sugar or milk-sugar, may be added to supply the carbohydrates. Or carefully prepared sweet whey containing milk-sugar, or barley water, may be added to the thin cream in place of some of the pure water. The following recipes have been used with good results: Mrs. Pospyhala’s Recipe =Infant Food.=—Warm 1½ quarts of milk to blood heat. Remove from fire and add one Junket Tablet dissolved in a spoonful of cold water. Let the milk set until it forms a solid mass, then stir it up in order to break the curd. Place it back on the fire and stir until quite smooth, not allowing it to get any warmer than blood heat. It is then ready to strain through two thicknesses of cheese-cloth and care must be taken to squeeze well so as to obtain as much of the whey as possible, which is very important. Add one tablespoonful of sugar to sweeten. Pour into nursing bottles, the amount being according to the age of the baby. A sufficient number of bottles are prepared for 24 hours’ feeding. Care should be taken to keep the milk in a cool place as it will sour the same as fresh milk. Every time the baby is fed the milk must be warmed by placing the bottle in a pan of water and heating to the right temperature. _Mrs. Rorer’s Recipe_ Where cow’s milk, even when diluted, or partly modified as in the home fashion, disagrees with the infant, this mixture may be used with good results: heat two quarts of milk to 100° F. Add two Junket Tablets dissolved in a tablespoonful of cold water. When the milk is congealed and perfectly solid draw through it backward and forward an ordinary four-tined silver fork; this will separate the curd. Strain through two thicknesses of cheese-cloth, saving the whey as this is the part you are to use; add a pint of water, a half ounce of sugar of milk, three ounces of cream and four ounces of the white of egg. The whites may be dropped into a quart fruit jar, a pint of the whey added, the top screwed on and the jar thoroughly shaken until the whites are well mixed with the whey; then add them to the remaining quantity and stand at once in a very cold place. This will be given in quantities from two to three ounces in an ordinary nursing bottle. _RECIPES_ _of the Nathan Straus Laboratories_ Formula by Dr. A. R. Green for 1st to 4th week:— ¾ ounces of 16% Cream 3 ounces of Full Milk 19 ounces of Water 1½ ounces Milk Sugar This mixture fills 8 bottles—each to contain 3 ounces. Feed 2½ hours apart. Formula by Prof. A. Jacobi for 3d to 7th month:— 18 ounces of Full Milk 18 ounces of Barley Water 1 ounces of Cane Sugar 20 grains of Table Salt (less than ¼ teaspoonful) This mixture fills 6 bottles—each to contain 6 ounces. Feed 3 hours apart. Formula by Prof. R. G. Freeman for 1st to 3d month:— 1½ ounces of 16% Cream 3 ounces of Full Milk 13 ounces of Water ½ ounce Lime Water 1 ounce Milk-Sugar This mixture fills 6 bottles—each to contain 3 ounces. Feed 3 hours apart. Formula by Dr. A. F. Hess for 7th to 9th month:— 22½ ounces of Full Milk 7½ ounces of Oat or Barley Water 1½ ounces of Cane Sugar 30 grains of Table Salt (about ¼ teaspoonful) This mixture fills 5 bottles—each to contain 6 ounces. Feed 3½ hours apart. Formula by Prof. R. G. Freeman for 2d to 6th month:— 18 ounces of Full Milk 16½ ounces of Water 1½ ounces of Limewater 1½ ounces of Milk Sugar This mixture fills 6 bottles—each to contain 6 ounces. Feed 3 hours apart. After 9th month:— Full pasteurized milk, 8 ounces every 4 hours. When the modified milk can be obtained from a dairy laboratory where it is prepared with scientific care and accuracy, it is better to use it than to depend on home-made preparations, and in many cases a doctor’s prescription may be necessary. Even if the modified cow’s milk is prepared so as to contain apparently the same proportion of the various groups of nutrients as mother’s milk, there may still be some essential difference. For instance, the protein in human milk consists mainly of albumin, while that of cow’s milk is mostly casein. It is often a question whether the individual baby can digest the casein without trouble. A trifle of rennet ferment,—a fraction of a Junket Tablet,—added to the modified cow’s milk just before feeding may be beneficial to overcome that defect. A little limewater also is healthful as it neutralizes any acid that may develop in the mixture. For the particular needs of the individual baby, a competent doctor should be asked to prescribe. MILK FOR GROWING CHILDREN [Illustration] When the child is big enough to thrive on undiluted, unmodified cow’s milk, it should not only be allowed, but urged, to continue on a diet in which this, the best of all foods, is the most essential part. An excellent form in which to feed milk to the growing child is junket. Eaten slowly with a spoon as a pudding, it is exposed to the action of digestion much better than milk swallowed by the glassful in a hurry and even if it is cold there is no danger of defective rennet action in the stomach because such action has already taken place. Doctors still disagree as to the desirability of pasteurizing milk for young children (see “Pasteurization,” Chapter I), some holding that the digestibility is affected by the process. The truth is probably that strong pasteurization at a temperature above 157° and holding the heated milk unnecessarily long at such high temperature do change the properties of the milk so as to make it harder to digest, but that the main difficulty is in the change of diet from raw to pasteurized milk or vice versa. Let the child get used to the change by making it gradual, diminishing the amount of one and increasing the amount of the other from day to day in a week, until the change is completed, and there will usually be little if any trouble. The secretions of digestive ferments in the stomach soon adapt themselves to the change in the food. The same holds good in case of other changes, as, for instance, from whole milk to more or less fatless milk, with additions of cereals or other partial substitutes;—it is always advisable to make any change in the child’s diet gradual. ------------------------------------------------------------------------ CHAPTER V MILK COOKERY Milk should also be used a great deal more than it is by grown persons, not only as a drink but in the daily cookery. In some homes milk in some form is a part of every menu and the meals are more delicious, attractive and nourishing than the ordinary milkless diet, and are also less expensive, as the milk takes the place of part of the meat. Dr. Graham Tusk of Cornell University, who represented the United States on the Interallied Council of Alimentation, says: “No family of five should spend any money for meat until three quarts of milk have been purchased, and this should be done even though the price of milk should go to twenty cents a quart. Absolutely nothing in the food line will keep children so healthy as their daily supply of milk.” In cooking with milk it is well to remember: 1. That, although milk is a liquid, it contains a large amount of solid food and of exceedingly nourishing, palatable and easily digestible food, much more than many vegetables or fruits. While milk has 13% of solid matter, water-melon has only 2%, turnips 4%, beets 12%, etc. When substituting milk for water, you add _nourishment_ to the food and it is well to keep in mind the ingredients,—the amount of protein, fat, etc.,