CAUSES OF RIPENING CHANGES 



359 



appear to be associated with the continued forma- 

 tion of lactic acid, resulting in larger amounts of 

 calcium lactate and acid phosphate. To what ex- 

 tent temperature and action of rennet-enzym share 

 in producing these changes cannot be definitely 

 stated now. It has been pretty satisfactorily estab- 

 lished that in cheddar cheese-making there is, con- 

 trary to what was believed at one time, no 

 combination of any kind between the lactic acid and 

 the protein of the cheese-curd, but that the acid 

 formed is practically all used by the lime salts of 

 the curd in the formation of the calcium compounds 

 mentioned. 



During the cheese-making process, the cheese-curd 

 or paracasein undergoes some very marked changes, 

 as we have just noticed above. We have a simple 

 means of measuring the extent of these changes, 

 depending on the behavior of the curd when treated 

 with warm (123 to 132 F.), dilute brine (a 5 per 

 cent solution of common salt in water) (p. 330). 

 The changes taking place and thus measured can be 

 illustrated as follows, using the results of a special 

 experiment, taken from the records of the New York 

 experiment station: 



It is seen that the increase of the brine-soluble 

 protein is very rapid between the time when the whey 



