226 CREAM RIPENING 



regularly observed, resulting in butter of poor flavor and of 

 inferior keeping quality. But this butter made from sour cream 

 showed a high aroma and flavor which sweet cream butter did 

 not possess. The consumer became accustomed to this high 

 flavor, learned to like it and gradually demanded it. 



In order to satisfy this demand the souring or ripening of 

 cream was gradually adopted even in dairies and later in cream- 

 eries where the cream was available in sweet condition and 

 where it was churned daily. As the fundamental principles of 

 cream ripening became better understood, and with the help- 

 ing hand of science, the process of cream ripening was gradu- 

 ally perfected, eliminating as far as possible some of the agen- 

 cies detrimental to good butter, and intensifying those agencies 

 which became known to produce the best results. In this evo- 

 lution the most prominent factors that assisted in the improve- 

 ment of the process of cream ripening and of the quality of 

 the resulting butter were, the advent of the centrifugal sepa- 

 rator, which gradually replaced the gravity can; the introduc- 

 tion of pasteurization of milk or cream, which removed the 

 great majority of undesirable bacteria and other forms of germ 

 life, and the adoption of pure culture starters which made pos- 

 sible the almost exclusive development of ferments produc- 

 ing the desired flavor and aroma. 



Purpose. The principal objects of cream ripening as now 

 practiced are: 1. To give the butter the desired flavor, aroma 

 and texture; 2. to produce uniformity of quality and 3. to 

 increase the exhaustiveness of churning. 



1. To Produce Flavor and Aroma. The exact and specific 

 agents which are responsible for the characteristic and desired 

 butter flavor and aroma during the ripening process, have not 

 as yet been conclusively determined. The fact that milk and 

 cream, when souring in the natural way, contain very greatly 

 predominating numbers of lactic acid bacteria, especially Strep- 

 tococcus lacticus and Bacterium lactis acidi, has led to the 

 assumption that these species of lactic acid bacteria play an 

 essential part in the production of the characteristic flavor and 

 aroma in butter. This has been further borne out by the fact 

 that when inoculated into sweet cream these micro-organisms 



