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Cheese is the curd of milk which has been 

 separated from it, pressed, and undergone some 

 fermentation. The precipitation is produced 

 either by allowing the milk to become sour 

 — when the lactic acid is the agent — or by rennet. 

 The first-named method is mainly applied to the 

 manufacture of so-called Dutch or sour-milk 

 cheese, green Swiss cheese, and cottage cheese. 

 More commonly cheese is obtained by means of 

 rennet derived from the fourth stomach of the 

 calf. The action is due to an enzym which 

 acts directly on the proteins and does not pro- 

 duce its affect through the intervention of acids. 

 The curd (cheese) undergoes, by keeping, various 

 decompositions, some essentially putrefactive, 

 and due to the action of microbes. The de- 

 composition of the cheese is termed "ripening." 



In the sour milk cheeses, ripening is restricted 

 intentionally, since there is liability to an irregular 

 and miscellaneous bacterial growth by which the 

 fermentations may be carried too far, undesirable 

 and even harmful products being formed. Such 

 cheeses are intended for prompt use. 



Cheese contains no casein, if by this term 

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