Pasteurizing milk does not kill the ferments in the milk, but it kills almost all bacteria except the spore-bearing bacteria, of which the gas bacillus is the most important.
TO STERILIZE MILK.
Boil milk for five minutes and then prepare as for pasteurizing, keeping it at temperature of 147° F. for thirty minutes and cooling it by the same process as given for pasteurization.
Boiling milk kills all bacteria. It is said that heating of milk to this degree impairs its nutritive value.
Note.—Spores develop quickly in lukewarm milk, therefore the necessity of cooling it quickly and placing it in refrigerator.
MODIFIED MILK.
Add water or other substances to cow’s milk to change it to agree with the digestion of the infant. Malted foods when mixed with water are deficient, and by adding milk or cream it becomes modified milk.
All mixtures should be cold when adding milk, and water sterilized when used as a diluent.
Note.—The natural food for the infant is human milk. The breast-fed babies are healthier, more vigorous, and more resistant to disease. (See Rickets and Scurvy.)