168 



Dairy Bacteriology. 



sential that the bacteria of the starter be able to form 

 not only acid, but sufficient flavor-forming substances to 

 impart to the butter a desirable flavor. In cheese mak- 

 ing it is not probable that this latter characteristic is of 

 any particular importance. 



FIG. 36. BACTERIA IN CHEESE. 



A photomicrograph of curd at the time the salt is added. 

 The lactic acid bacteria have increased materially in num- 

 bers. 



It is desirable that the process of cheese making shall 

 conform as closely as possible to that which experience 

 has shown to give the best results. The rate at which 

 acid is developed in the curd and the rapidity with 

 which the whey is expelled therefrom should bear a cer- 

 tain ratio to each other. If the milk has too high a de- 

 gree of acidity, i. e., is overripe, the acidity developed 

 in the curd will be too high before the curd is sufficiently 

 firm ; with a very sweet milk, the reverse may be true. 



