128 Dairy Bacteriology. 



case, the fermentative changes are well under way when 

 it reaclies the central station, and as the cream is secured 

 from a number of different persons in a partially ripened 

 condition, it is far from being uniform in character. 

 Where centrifugal cream separators are used, the cream 

 is secured sweet, thereby permitting a supervision of the 

 ripening process at the central station where the butter 

 is made. 



This control of the ripening process exerts a profound 

 influence on the character of the fermentation that takes 

 place, and naturally modifies the product. The uni- 

 formity of methods employed necessarily has a tendency 

 to render the product more uniform. 



A. BENEFICENT ACTION OF BACTERIA IN BUTTER. 



126. Ripening- of cream. The ripening changes that 

 occur in cream are exceedingly complex, and our knowl- 

 edge concerning the same is as yet far from satisfactory. 

 The present belief is that these fermentations are largely 

 the result of bacterial action, as germ growth is very 

 abundant. Conn 1 found in fresh cream 4,060,000 bac- 

 teria, while the ripened cream contained 346,000,000. 



In the ripening of cream at least three different fac- 

 tors are to be taken into consideration, the development 

 of acid, flavor and aroma. Much confusion in the past 

 has arisen from a failure to discriminate between these 

 factors. While all three of these qualities are produced 

 simultaneously in ordinary ripening, it does not neces- 

 sarily follow that any single organism is able to develop 

 all three qualities. If this ripening is allowed to go too 

 far, undesirable rather than beneficial decomposition 

 products are produced. These greatly impair the value 

 of butter, so that in a sense the commercial value of this 



1 Conn, Storr's Agric. Expt. Stat., 7: 72, 1894. 



