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MANUAL OF MILK PRODUCTS 



and its flavors are usually bad. About one-third to one pint of 

 milk is sufficient for most cultures. Glass jars, enameled ware, 

 china, earthenware, and tin are the best utensils for this pur- 

 pose. 



"The lactic acid bacteria grow the most rapidly at 95° to 108° 

 F. But in impure cultures, like a starter or milk, there are 



Fig. 48. — Power starter can with water jacket and mechanical stirrer. 



bacteria that can compete more successfully with the lactic acid 

 fermentation at high or low temperatures than at mean temper- 

 atures. Thus at high temperatures stale flavors and gassy fer- 

 mentations are frequent, and it is difficult to avoid over-ripening. 

 Bitter and other undesirable flavors are common at low temper- 

 atures. It is possible to ripen successfully at 55° to 90°, but the 

 best flavor is developed at 60° to 75° F. It is better to ripen a 



