PASTEURIZATION 181 



CHAPTER VIII. 

 PASTEURIZATION. 



Definition. As applied to buttermaking, pasteurization may 

 be denned as the process of heating 1 milk or cream to a tem- 

 perature capable of destroying the great majority of bacteria 

 and other ferments contained therein and of cooling quickly to 

 the ripening or churning temperature. 



In proper pasteurization the milk or cream is heated to 

 145 degrees F. and held at that temperature for at least twenty 

 minutes or it is heated to from 176 to 185 degrees F. and cooled 

 without holding. Proper pasteurization may also embrace any 

 modification of the above relations of temperature to time of ex- 

 posure that is equivalent in germ-killing efficiency to the above 

 processes and has otherwise no injurious effect on the flavor 

 and texture of butter. If the cream is to be ripened subse- 

 quently, it is cooled after pasteurization to about 65 degrees F. 

 If the ripening process is dispensed with the cream is cooled 

 after pasteurization to the churning temperature which will gen- 

 erally vary from 45 degrees F. to 60 degrees F., according to 

 locality and season of year. 



Objects of Pasteurization. Pasteurization does not make 

 possible the manufacture of fancy butter from a poor grade of 

 cream, but it does help the creamery to minimize the injurious 

 effect of contamination of milk and cream with diverse types 

 of germ life and ferments injurious to the quality of the butter 

 and possibly dangerous to the health and life of the consumer. 

 Proper pasteurization, therefore, improves the quality, and keep- 

 ing properties of butter and makes the product safe for consump- 

 tion. Briefly, the chief objects of pasteurization of cream for but- 

 termaking are: Improvement of flavor of butter, better keeping 

 quality, more uniform flavor and quality, destruction of germs 

 of human and animal diseases, increase of economic efficiency 

 of dairy industry. 



Improvement of Flavor. Proper pasteurization improves 

 the flavor of butter, partly, because it destroys the great major- 

 ity of ferments present in the cream, some of which are prone 

 to decompose one or more of the ingredients of butter, produc- 



