DAIRYING 213 



Care of Milk. — As milk is so extensively used as a 

 human food, the proper care of it needs to be emphasized. 

 Attention should be given to 



The Stable. — This must be well lighted and ventilated 

 to assist in keeping it free from bacteria and odors. Dust 

 also should be prevented as much as possible, and coverings 

 should be provided for the pails while in the stable. 



The Cow. — She should be kept scrupulously clean, and 

 her udder and teats should be washed before milking. All 

 milch cows should be curried. 



The Milker. — The person who milks should wear clean 

 clothes and have clean dry hands. The hands should never 

 be put in the milk. 



The Utensils. — Porcelain or smooth tin pails without 

 open seams are best. These should be scalded after every 

 milking and allowed to stand in the sun and air. The 

 churn should be scalded also, as well as the parts of a sep- 

 arator, and all bottles. 



Keeping. — Milk should be removed from the stable as 

 soon as possible and chilled. Low temperatures are un- 

 favorable to bacteria. The milk should be kept where it 

 will not be possible for it to absorb any unpleasant odors, 

 as it is inclined to do. 



Souring. — Very minute plants, called bacteria, find in 

 milk a fertile field for development. In their growth they 

 change the milk sugar to lactic acid, which "sours" the 

 milk and curdles it. This may be prevented by extreme 

 cleanliness and low temperature which does not favor 

 the growth of bacteria. 



Pasteurization. — Milk may be kept longer by heating 

 it for twenty minutes at a temperature of 160° F. and 

 then cooling it rapidly. This process is called Pasteuriza- 

 tion. It destroys any bacteria that may be present. In 

 many cities there is a law that milk must be so treated. 

 When milk is heated above 180° F., as at that temperature 

 there is extra certainty that the bacteria will all be killed, 

 it is said to be ''sterilized." 



Sanitary plants, to produce absolutely pure milk, take 

 all these precautions. 



