CATTLE PRODUCTS 353 



milk is evaporated to dryness without burning. Before being 

 used it is mixed with water. 



Modified milk is prepared for use of infants and invalids, 

 by increasing or decreasing one or more of the parts of the 

 milk, to suit special cases. 



Fermented milk and ripened milk are made from skim 

 milk or from whole milk. The proper bacteria are added to 

 cause the souring and thickening of the milk, as cream is 

 ripened for churning. When ready for use it is somewhat 

 similar to buttermilk. 



Creaming. There are three common methods of obtain- 

 ing the cream from milk. (1) The shallow pan method is 

 the oldest and most common. (2) The deep can method is 

 sometimes used when much milk is to be handled. The 

 large cans of milk are kept in cold water until the cream 

 rises. The skim milk is drawn off through a faucet at the 

 bottom. (3) The modern centrifugal bowl separator is the 

 only quick way of removing the cream from milk (Figs. 

 220, 221). In all types of these machines the milk flows into 

 a rapidly whirling metal bowl. The speed is very great, 

 and the skim milk, being heavier, is thrown to the outer edge 

 and runs out. The cream overflows near the centre of the 

 bowl. 



Ripening Cream for Churning. As soon as cream is 

 separated from the milk it must be cooled and kept cold 

 until about twelve hours before it is to be churned into 

 butter. It is then warmed to a temperature at which the 

 bacteria will grow to make it sour. This may be 60 to 

 75 F. It will sour faster when warmer, but will not make so 

 good butter. At churning time the temperature should be 

 about 58 in the summer and 60 or 62 in the winter. 

 Ripened cream should be slightly sour to the taste and pour 

 as a thick, smooth, glossy liquid, free from lumps or curds. 

 When ready to churn, it should be poured through a strainer 

 to remove any curds that might be present. 



