Cream should represent at least 25 per cent of the fata of milk.
Skimmed Milk is the part of the milk left after the cream has been removed, and contains considerable proteid and sugar.
Butter-Milk is the part of the milk left after all the butter-fats have been removed; is not as nutritious as the above, but contains casein, lactin and salts.
Sterilized Milk is prepared by subjecting it to a tempera-ture of 212° F. for fifteen minutes or more. It is not readily digested, and should not be used.
Pasteurized Milk is prepared by subjecting it to a temperature of 160° F. for an hour. This presumably destroys all of the pathogenic bacteria it might contain. Such milk is easily digested, but should not be kept for use many hours after the bottle has been once opened.
Peptonized Milk is prepared by adding a definite amount (depending upon the maker of the preparation) of pep-Ionizing powder (pancreatin and sodium bicarbonate) to a quart of milk. The powder is generally dissolved in a little water before stirring it into the milk. The bottle should then ordinarily be placed in a warm place for an hour, then put on ice to inhibit further digestion. The peptonized milk may then be warmed and used as needed, but it should not be used after it is twenty-four hours old.
Koumyss is prepared by adding about a quarter of a fresh yeast cake, dissolved in a little water, to a quart bottle of milk, to which has been added a tablespoonful of sugar. The bottle should be tightly corked and placed upright in a cool place, but not on the ice. In two or three days it should be laid upon its side and then occasionally given a slight shake. At the end of five days fermentation is completed, and the preparation should then be pleasantly effervescent, have a sourish taste, and contain not far from two per cent, of alcohol and about twelve per cent, of solid nutriment. If the buttle is not opened at the end of the five days, it should be placed on the ice.
Junket is made by adding a tablespoonful of liquid rennet (or a dissolved tablet of rennet), to a pint of milk to which a tablespoonful of sugar dissolved in water, with a little brandy, or sherry, has been added. The covered dish or jar should then be put in a very warm place. As soon as there is solidification it should be placed in the refrigerator.