NEW-METHOD CHEESE-MAKING. 275 



experiments have already shown that the case is not hope- 

 less. 



Instead of following the method of controlling the fer- 

 mentation processes in the cheese through a " mass-infec- 

 tion," another may be practised which leads to a more 

 successful result, viz., the introduction of pure cultures, 

 the milk being pasteurized and strict cleanliness being ob- 

 served throughout the manufacture. The main points in 

 this method of manufacture, which we may call new- 

 method cheese-making, are considered in the following. 



1. Pure, Clean Milk. Such milk is obtained through 

 a careful observation of the directions given in the early 

 part of this work as to cleanliness in the stable and in the 

 hauling of the milk, and by pasteurization of the same. 

 If the milk has not become highly infected with bacteria 

 in the stable, even a slight heating may be of service for 

 the annihilation of the bacteria. Freudenreich has by prac- 

 tical experiments shown the great benefit of pasteurization 

 in the manufacture of cheese. The cheese made from 

 pasteurized milk did not cure on account of the small 

 number of bacteria contained in it; not until the milk 

 was inoculated with certain bacteria could the curing take 

 place. The pasteurized milk demands special methods for 

 the making of cheese, as cooling after the heating, use of 

 larger quantity of rennet extract, etc. 



2. Exclusion of Injurious Infection from the Surround- 

 ings. The main condition for the exclusion of harmful 

 infection from the surroundings is cleanliness in the 

 factory and in the factory men. If the objects sur- 

 rounding the milk are kept sufficiently clean, there will 

 be no danger in this direction. There is no need of entire 

 exclusion of all infection, as any small number of harmful 



