586 ANNUAL, REPORT OF THE Off. Doc. 



come from the use of these pure culture starters is uniformity in 

 character of the butter produced and better keeping quality. Full 

 directions for methods of use always accompany these special start- 

 ers and we do not need to consider them here. 



28. Amount of Acid Needed for Cream Ripening. 



The ripening of cream was, for a long time, the most ditlicult 

 step of butter-making to control, and the specially difificult point 

 in this operation was to determine the amount of acid that should 

 be present before churning. The appearance, odor and taste of the 

 cream are guides, to some extent, as to the amount of acid formed, 

 but they are far from reliable for accurate, uniform work. It is 

 very important that the same amount of acid shall be developed from 

 day to day in order to secure butter of uniform quality'. When 

 cream is ripened so as to show a test of five-tenths to six-tenths of 

 one per cent, of lactic acid, it produces a higher flavored butter 

 than that produced by cream ripened to four-tenths of one per cent, 

 of acid. When cream contains more than sixty-five hundredths of 

 one per cent, of acid, the flavor of the butter is too strong. More- 

 over, in such cases, the particles of coa'gulated casein become very 

 hard and form white specks in the butter. Such butter acquires 

 bad flavors quickly. The whey should never separate from the curd 

 in cream ripening. We now have an inexpensive, simple method for 

 determining the amount of acid in cream, and, while the method is 

 not strictly accurate, it is sufficiently close for all practical purposes 

 in cream ripening. For careful work in butter-making, this method 

 of determining the amount of acid in cream should always be used. 

 The method is fully described in section 90, p. 653, Chapter XI. 



29. Effects Produced by Cream Kipening. 



The effects of cream ripening are seen in several different ways, 

 among which we will notice the more important. 



(1.) Improved Flavor of Butter. — In order to secure butter with the 

 kind of flavor required by the average consumer, it appears to be 

 necessary to ripen cream. This is probably the most important and 

 far-reaching effect of ripening cream. The importance of flavor in 

 butter is easilv obvious, when we consider that flavor more than 

 any other factor determines the market price of butter. Poor cream 

 ripening means poor flavor and low price for butter. 



(2.) Ease of Churning. — It has been found true, especially in cream 

 raised by the gravity system, that cream churns more readily when 

 ripened. This is probably due to the influence of acid upon casein. 



