188 



BUTTER-MAKING. 



It seems that during cream-ripening the development of 

 acid, aroma, and flavor go hand in hand. This does not neces- 

 sarily indicate that they are produced by the same cause. It 

 is possible that the fla-s'or and aroma substances are chemically 

 produced from the various by-products of the germs. 



Bacteriologists do not agree as to what species of bacteria 

 is responsible for the high quahty of flavor and aroma of butter. 

 Conn * claims that the germs which act upon the nitrogenous 



Fig. 122. — The McAreav-y cream- 

 ripening vat. 



Pig. 123. — The Miller cream-ripening 

 vat. 



matter of milk are associated with the lactic-acid-producing 

 bacteria in the production of desirable butter flavors. Weig- 

 man asserts that the best results are obtained when a variety 

 of species work together in the cream. He has isolated a single 

 species of germ which produced alcohol and lactic acid as 

 by-products, and which, according to experimental evidence 

 deduced by him, is capable of producing the delicate butter 

 flavors. Freudenrich has also studied a species of germ which 

 produced alcohol and lactic acid as by-products, and was able 

 to produce the characteristic butter flavors. Eckles has studied 

 this question of flavor production during cream-ripening. He 

 comes to the conclusion that the flavor and aroma substances 



* Storr Station, Conn. 



