130 Testing Milk and Its Products. 



quantity of milk given, the readings obtained represent 

 per cent, of acidity direct. 



147. Rapid estimation of the acidity of apparently 

 sweet milk or cream, a, Milk. The alkaline tablet 

 method offers a ready means of estimating the acidity 

 of milk or cream that 

 is still sweet to the 

 taste. The selection of 

 the best kinds of milk 

 is especially important 

 in pasteurizing milk 

 or cream. As pre- 

 viously noted, milk 

 which gives the high- 

 est acid test contains, 

 as a rule, a larger 

 number of bacteria 

 and spores not de- 

 stroyed by pasteuriza- 

 tion than does milk 

 giving a low acid test 

 (129) ; the acidity test 

 may therefore be used 



to advantage for the FIG " 44 ' T^ Mamchaii add test, 

 purpose of selecting milk best adapted for pasteuriza- 

 tion, as well as such as is to be retailed or used in the 

 manufacture of high-grade butter and cheese. 



In distinguishing milk fit for pasteurization purposes 

 from that which is doubtful, an arbitrary standard of 

 two-tenths of one per cent, of acid may be taken as the 



