52 SCIENCE AND PRACTICE OF CHEESE-MAKING 



shrinking of curd. The knowledge of the relation 

 of acidity and temperature to contraction of curd 

 enables the cheese-maker to heat the curd in the 

 whey more rapidly, since, in the case of excessive 

 acidity at the start, he can increase with comparative 

 rapidity the temperature, without danger of harden- 

 ing the external film of the small pieces of curd and 

 so preventing further expulsion of whey. 



Acidity and expulsion of whey. The contrac- 

 tion of curd is closely associated with expulsion of 

 whey and the relation of acidity to the two actions 

 is practically the same. 



Acidity and color of cheese. Formation of too 

 great a degree of acidity bleaches the color in the 

 curd, making it pale when the action is even, and 

 mottled when the acidity is different in different 

 portions. This condition is generally caused by the 

 retention of too much milk-sugar (whey) in curd 

 and cheese. 



Acidity and body of cheese. Excessive acidity 

 produces imperfect body in cheese, making it 

 harsh, corky and mealy. A certain degree of acidity 

 is an essential condition, if not one of the causes, 

 of the formation of a smooth, firm, silky body. 

 Insufficient acidity may cause cheese to be weak- 

 bodied. 



Acidity and texture. Cheese made from curd 

 containing a small amount of acidity is often faulty 

 in texture. Among such defects are holes, usually 

 called "sweet holes." Excessive acidity and cracks in 

 cheese are often associated. 



Acidity and flavor. The characteristic flavor of 

 cheddar cheese is not developed without a certain 



