Cream may be sterilized and preserved in a pure state for some time, the same as milk.
Milk requires especial care to secure a good quality and quantity of cream. Scrupulous cleanliness, good ventilation, and an unvarying temperature are absolute essentials. The common custom of setting milk in pans is objectionable, not only because of the dust and germs always liable to fall into the milk, but also from the difficulty of keeping milk thus set at the proper temperature for cream-rising. Every family using milk in any quantity ought to have a set of creameries of large or small capacity according to circumstances, in which the milk supply can be kept in a pure, wholesome condition, and so arranged as to facilitate the full rising of the cream if desired. A very simple and satisfactory creamery, with space for ice around the milk, similar to that represented in the accompanying cut, may be constructed by any tinman.
The plan of scalding milk to facilitate the rising of the cream is excellent, as it not only secures a more speedy rising, but serves to destroy the germs found in the milk, thus lessening its tendency to sour. The best way to do this is to heat the milk in a double boiler, or a dish set inside another containing hot water, to a temperature of 150 deg. to 165 deg.F. as indicated by wrinkles upon its surface. The milk must not, however, be allowed to come to a boil. When scalded, it should be cooled at once to a temperature of about 60 deg. F. and kept thus during the rising of the cream.
Of all foods wholly composed of fat, good fresh butter is the most wholesome. It should, however, be used unmelted and taken in a finely divided state, and only in very moderate quantities. If exposed to great heat, as on hot buttered toast, meats, rich pastry, etc., it is quite indigestible. We do not recommend its use either for the table or for cooking purposes when cream can be obtained, since butter is rarely found in so pure a state that it is not undergoing more or less decomposition, depending upon its age and the amount of casein retained in the butter through the carelessness of the manufacturer.
Casein, on exposure to air in a moist state, rapidly changes into a ferment, which, acting upon the fatty matter of the butter, produces rancidity, rendering the butter more or less unwholesome. Poor, tainted, or rancid butter should not be used as food in any form.
Good butter is pale yellow, uniform throughout the whole mass, and free from rancid taste or odor. White lumps in it are due to the incorporation of sour milk with the cream from which it was produced. A watery, milk-like fluid exuding from the freshly cut surface of butter, is evidence that insufficient care was taken to wash out all the buttermilk, thus increasing its liability to spoil.
The flavor and color of butter vary considerably, according to the breed and food of the animal from which the milk was obtained. An artificial color is often given to butter by the use of a preparation of annatto.