CHAPTER XXI. 



PASTEURIZATION 0^ MILK AND CREAM. 



The process known as pasteurization derives its name 

 from the eminent French scientist Pasteur. It consists 

 in heating and cooUng milk and cream in a manner which 

 will destroy the bulk of bacteria in them, but which will 

 leave their chemical and physical properties unchanged 

 as far as possible. 



Advantages of Pasteurization. The advantages to 

 be derived from pasteurization vary with the conditions' 

 under which the milk is produced and the efficiency with 

 which the work is conducted. If the milk comes from 

 dairies where disease and uncleanliness prevail, pasteur- 

 ization will prolong the keeping quality of the milk and 

 also materially lessen the danger from disease germs. 

 If, on the other hand, healthfulness and cleahliness re- 

 ceive the exacting attention which prevails on certified 

 dairy farms, nothing can be gained by subjecting milk 

 to the pasteurizating process. 



Disadvantages of Pasteurization. The principal dis- 

 advantages are as follows: (i) the cost of pasteurizing 

 apparatus; (2) the cost of pasteurizing; (3) the tendency 

 to promote uncleanliness on the part of the producer; (4) 

 the tendency to reduce the cream line on the milk; 

 (5) lessening of the whipping property of the cream; 

 and (6) the tendency to impart a "cooked" flavor to the 

 milk and cream. 



Methods of Pasteurization. Two general methods 



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