CHAPTER XVII 



THE RELATION OF MICROORGANISMS TO 

 BUTTER AND CHEESE 



The preparation of condensed milk and milk powder rep- 

 resents a method of conserving milk in a less bulky form 

 than the original product, a great advantage when it is to 

 be transported for long distances. The manufacture of 

 butter represents a method of concentrating the butter fat 

 of the milk, while in cheesemaking the fat and the casein, 

 together with a small part of the milk serum, are concen- 

 trated. 



It is essential that the butter and cheese shall possess cer- 

 tain physical and chemical properties. Most important 

 among these properties is the flavor. The flavor of foods 

 is very important, an agreeable odor and pleasant taste in 

 any food making it much more appetizing, if not influ- 

 encing its nutritive value. The use of condiments and 

 flavoring substances of all kinds in many foods is evidence 

 of the value of flavor in foods. 



If cream is separated from sweet, fresh milk, and the 

 remaining part of the milk serum is eliminated by the 

 churning process, the butter thus obtained will be devoid 

 of flavor, and, to those accustomed to butter made from 

 cream that has been allowed to sour before being churned, 

 it is not at all attractive. Sweet-cream butter is made in 

 all the countries of southern Europe, while that from fer- 

 mented cream is made in northern Europe, America, Aus- 

 tralia, Asia, and South America. Sour or acid cream but- 

 ter, therefore, represents the great mass of the butter sup- 

 ply of the world. 



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