l8 DAIRY TECHNOLOGY 



through fermentation. About one per cent of sugar is 

 required to produce the amount of lactic acid mentioned 

 above. In this change of milk sugar to lactic acid, other 

 by-products are simultaneously produced. The complete- 

 ness with which the milk sugar is transformed into lactic 

 acid depends upon the species of germs present. Butter- 

 milk then contains more acid and less sugar than skim 

 milk. 



It is also claimed that the casein in buttermilk is easier 

 to digest, because it exists in a more soluble form, being 

 partly combined with lactic acid in the form of casein 

 lactate. 



Buttermilk is used extensively as a beverage. When 

 the cream has been properly ripened, the buttermilk is 

 not only nutritious but it is healthful. Some physicians 

 prescribe it for their patients. It is widely believed that 

 it may be used successfully as a remedy for kidney trouble. 



Buttermilk is used extensively as a food for hogs and 

 chickens. 

 ( The average composition of buttermilk is : ^ 



— ■ Per cent. 



Water 9° • 5° 



Fat 0.20 



Casein and albumen 3 30 



Milk sugar 5-3° 



Ash 0.70 



Cream. — Cream is the portion of milk containing 

 most of the fat. It may be separated either by gravity 

 or by a centrifugal separator, and to be legal, cream may 

 contain from 18 to 50 per cent fat, and even more. Market 

 cream normally contains 18 to 25 per cent fat. The fuel 

 value of a pint of cream is about 1425 calories, more than 

 four quarts of milk. However, cream is lacking in pro- 



' Snyder — Dairy Chemistry. 



