112 Minnesota Plant Life. 



cial inoculation. But a cheese made in Minnesota may be in- 

 oculated with Edam germs or Brie germs, and if the control of 

 its manufacture were as perfect as that which has been attained 

 through the researches of Pasteur in the brewing industry, 

 there would be little difficulty in sending out such choice prod- 

 ucts from any dairy in the world. Indeed, in Denmark, where 

 dairy industries have reached such high perfection, pure cul- 

 tures of Edam bacteria can be everywhere obtained and Edam 

 cheeses can be manufactured at will. The flavor of the cheese 

 and its odor come largely from ethers which are the result of 

 bacterial activity. Since certain bacteria produce certain ethers, 

 it is evidently necessary to keep careful control over the growth 

 in the cheese and through failure to do this, highly offensive 

 odors are exhaled by the cheeses of careless dairymen. This re- 

 sults from putrifactive germs gaining ingress to the mass and 

 such cheeses, w'ithout straining the language, may be called dis- 

 eased. A peculiar form of diseased cheese is the blozvn cheese 

 in which gas-forming bacteria produce bubbles large enough to 

 dcstrov the i)roper texture of the mass. Cheese may also be 

 soured bv the presence of lactic-fermenting bacteria, as well as 

 by offensively-scented and undesirable but_\ric forms. 



Ripening of cheese. One is now in a ])osition to under- 

 stand the various processes described as the rii)ening of cheese. 

 After the cheese has been set away to ripen, and during this 

 process, there is o])])()rtunit\ for the growth of desirable bacteria 

 and moulds — for some kinds of cheese such as Stilton, are de- 

 ])endent for their flavors largely upon mould, ^^'hen a dairy is 

 manufacturing bad cheese it is evident that llie "sanitation" has 

 been poor, or that (|uarantine methods should have been adopted 

 against offensive germs. Hence it is easy to understand how 

 necessary is cleanliness in the dairy, for the practice of cleanli- 

 ness includes both (|uaranlinc and sanitation. 



Diseases of butter. All that has been said about cheese ap- 

 plies equally to butter, for the ilavor of this i)roduct, including 

 both its taste ruid odor, is dependent upon bacterial activity. 

 Diseases of bultcr exist — of wliicli raiicid butter mav serve as an 

 illustration. 



Diseases of eggs, bread, milk and cigars. .Many other arti- 

 cles of tood or stinnilants ni;i\ be diseased in the sense in which 



