no AGRICULTURE 



twenty-four hours, and in winter from two to 

 three days. The results by this method are 

 uncertain. The best temperature, where 

 cream is ripened after this fashion, is from 

 58 to 60 F. 



2. The cream may be raised to 95 (the 

 temperature at which bacteria work best), and 

 is then allowed to fall to the temperature of 

 the air, after which ripening is very much 

 hastened. 



3. By adding a "starter" to the cream. 

 A starter may be any liquid in which a con- 

 siderable quantity of acidity has been already 

 developed, such as sour milk, cream, or 

 butter-milk, or it may be a liquid inoculated 

 with a pure culture of the lactic acid bacillus. 

 Ripening is brought about by certain kinds of 

 micro-organisms, which in their growth pro- 

 duce lactic acid. By obtaining the desired kind 

 of micro-organism and growing it alone, a 

 " pure culture" is the result. This u pure 

 culture " is next put into milk, which then 

 becomes "a starter." 



