Page:Food and cookery for the sick and convalescent.djvu/53

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Put milk in sterile, small-mouthed glass bottles, stop with cotton batting or absorbent cotton, place bottles in wire basket, immerse basket in kettle of cold water, and heat water gradually, to a temperature of from 158° to 167°. Keep at same temperature thirty minutes. Remove bottles, cool quickly, and put in a cold place. By this process almost all of the disease germs are killed; also those germs which produce souring; but the spores, which are not killed, will develop after a few days.

Proceed as in the pasteurization of milk, raising the temperature of the water to the boiling point (212° F.), and keeping at this temperature thirty minutes. Sterilization is an efficient method of destroying all germs, but alters the taste of milk, coagulates the albumen, destroys the fine emulsion of fat, and renders the casein less easy of digestion.

Sterilizers are on the market which simplify the process of sterilization, and their use is recommended where expense need not be considered.