DEFECTS IN BODY AND TEXTURE 1 27 



Acidity usually appears in the milk quite slowly, even 

 after the curd has been first cut. When the formation 

 of acid once starts, it increases very rapidly. This is 

 usually during the interval when the whey is removed. 

 The acid increases rapidly and the curd tends to 

 become soft or mushy. In the cheddaring process the 

 curd may become more or less filled with large, shining 

 openings, resembling gas-holes. After milling, the 

 curd is usually very slow to contract and, in severe 

 cases, may soften and lose its body. Frequently yeasts 

 are accompanied by gas-producing bacteria and, when 

 this combination is encountered in cheese-making, it 

 is very difficult to make cheese of passable quality. 

 Whey from such cheese, when whey tanks are not 

 frequently cleaned, may appear to boil, as though over 

 a fire. 



Cause : 



Yeasts which gain entrance to milk. They have been found 

 on hay-dust, leaves of trees, in unclean cellars, and in whey- 

 tanks. 



(1) In cheese-factory work, the whey tank is the great 



source of germ contamination. 



(2) Allowing milk to be exposed to the dust of stables 



after milking (p. 6). 



(3) Keeping milk too warm after placing it in the cans. 



Prevention : 



(1) After milk is drawn, it should immediately be taken 



into a clean atmosphere and cooled to 60 F., and 

 better to 50 F. 



(2) Whey-tanks should be cleaned and scalded twice 



a week, at least, and, better still, every day. 



(3) All the whey should be pasteurized. 



(4) All cans and utensils used in carrying milk should be 



thoroughly cleaned and scalded. 



Remedy : 



When it is known that yeast -infected milVt has been re- 

 ceived, it should be treated in the following way: 



