M ilk and Its Products. 



289 



perature than this can be used, with great improvement in the 

 quality of the product. In the manufacture of Swiss cheese the 

 milk must be in a sweet condition. No acid is developed and the 

 curd is cooked at a temperature of 125 to 130 F. The curd is 

 placed in molds and the salting done by surface application. In 

 making soft cheese the curd is not cut or pressed, but simply 

 allowed to drain on a cloth or frame. 



Reckoning that the fresh cheese which goes into the cheese 

 room contains about 36 per cent of water, the products from 100 

 Ibs. of normal milk will be as follows: 



Products from 100 Lbs. of Normal Milk. 



Ripening. Cheddar cheese ripens quickest at a moderately 

 warm temperature, 50 to 60 F. being usually employed. It has 

 been shown that it will also ripen at a much lower temperature 

 even at 30 F. and the product will be of excellent quality. The 

 time of ripening is necessarily longer when conducted at the 

 'lower temperature. During this curing process many complex 

 changes occur. The sugar is converted to lactic acid, some water 

 evaporates, and the insoluble proteins are partly converted into 

 water soluble products. Ammonium compounds are also pro- 

 duced during the ripening process. Experiments have shown 

 that fresh cheddar cheese contains but from 5 to 10 per cent of 

 its protein in water soluble form, while at the end of 5 months, 

 35 to 40 per cent will be found in that form. These changes, ac- 

 cording to one view, are produced primarily by the lactic acid 

 organisms. Another theory ascribes them to enzymatic action, 

 the enzymes being galactase, which is present in all milks and 



