CLASSIFICATION 87 



in products with 45 to 75 per cent of water. If such 

 growth is permitted, enzymic activities follow quickly 

 with resultant changes in appearance, texture, odor 

 and taste. Refrigeration is necessary to transport such 

 cheeses to the consumer, if properly ripened. Trade in 

 these forms may continue throughout the year in cool 

 climates and in places where adequate refrigeration is 

 available. Practically, however, outside the large cities 

 this trade in America is at present limited to the cold 

 months; inside the large cities much reduced quantities 

 of these cheeses continue to be handled through the year. 



In the stricter sense, the soft group of cheeses falls 

 naturally into two series: (1) the varieties eaten fresh; 

 and (2) the ripened soft cheeses. Those eaten fresh have 

 a making process which commonly involves the develop- 

 ment of a lactic acid flavor by souring, but no ripening 

 is contemplated after the product leaves the maker's 

 hands. In the ripened series, after the making process 

 is completed, the essential flavors and textures are de- 

 veloped by the activity of micro-organisms during ripen- 

 ing periods varying in length but fairly well-defined for 

 each variety. 



In contrast to the soft cheeses, the hard kinds are 

 low in water-content, ripen more slowly and may be 

 kept through much longer periods. They retain their 

 form through a wider range of climatic conditions. They 

 develop flavor slowly and correspondingly deteriorate 

 much more slowly. Such cheeses are in marketable con- 

 dition over longer periods. In their manufacture the 

 cooking of the curd takes a prominent place. 



109. Relation of heat to classes. The close relation 

 between the heat applied and the product sought forms 

 the basis of a striking series of graphs (Fig. 12, page 78). 



