without souring. If the milk is tainted in any way it will sour in a
few hours. Boiled milk will keep fresh half as long again as fresh
milk. Milk absorbs odors very quickly, therefore should never be left
in a refrigerator with stale cheese, ham, vegetables, etc., unless in
an air-tight jar. It should never be left exposed in a sick room or
near waste pipes. Absolute cleanliness is necessary for the
preservation of milk; vessels in which it is to be kept must be
thoroughly scalded with boiling water, not merely washed out with warm
water.


_Methods of Preserving Milk._

STERILIZED MILK.

Milk to be thoroughly sterilized and germ free must be heated to the
boiling point (212° F.). This may be done by putting the milk into
perfectly clean bottles and placing in a rack, in a kettle of boiling
water, remaining until it reaches the necessary degree of heat. The
bottle should be closely covered _immediately_ after with absorbent
cotton or cotton batting in order to prevent other germs getting into
the milk.

PASTEURIZED MILK.

The difference between pasteurizing and sterilizing is only in the
degree of heat to which the milk is subjected. In pasteurizing, the
milk is kept at a temperature of 170° F. from 10 to 20 minutes. This
is considered a better method for treating milk which is to be given
to young children, as it is more easily digested than sterilized milk.