46 Dairy Bacteriology. 



The absorption of flavors by old milk is sometimes 

 puzzling to distinguish from a bacterial trouble, but if 

 the surroundings are closely noted, the cause can usually 

 be traced to delayed absorption of bad odors from the 

 room where milk is stored. 



If the trouble is of bacterial origin, it can frequently 

 be detected by transferring a small quantity of the sus- 

 pected milk to a fresh lot, preferably that which has first 

 been boiled. If due to a living organism, the abnormal 

 fermentation will be propagated and so reproduce the 

 difficulty in the infected milk. 



B. INFECTION OF MILK IN THE FACTORIES. 



50. Treatment of milk in factories. Where milk 

 is taken to a creamery or cheese factory, the method of 

 treatment often modifies the bacterial life of the milk to 

 -a marked degree. 



Butter and cheese-making both require the presence of 

 bacteria, but the germ life must be of the right sort to 

 be beneficial in its action. For this reason the maker 

 wishes the milk to be as free as possible from all contam- 

 inating influences. If the foregoing suggestions are in- 

 telligently followed, the raw material will be turned over 

 to the factory in prime condition ; but the rational treat- 

 ment must be continued here if the best of products is to 

 be expected. Numerous influences are at work in the 

 factory that add their mite to the milk in different stages 

 of its manufacture, and ultimately affect in a serious 

 way the final product. Of course, very much depends 

 upon the proper observance of physical conditions, but 

 -a brief outline of some of the possible dangers will also 

 be pertinent. 



The cardinal precept in the factory as well as on the 

 farm should be cleanliness. Cleanliness here must not 



