232 AGRICULTURAL BACTERIOLOGY. 



producing a good flavor had been determined by experiment. 

 This method is, of course, logically, perfectly satisfactory ; for, 

 since pasteurization destroys most of the bacteria present in the 

 cream, it follows that the ripening will be produced by the 

 species of bacteria of which a pure culture has been added. 

 Professor Storch was soon followed, in north Germany, by 

 Professor Weigmann and others, and the method adopted in 

 Copenhagen was soon extended more or less widely in north 

 Germany and Denmark. In Denmark it is now used almost 

 universally, and in north Germany quite widely, in general 

 dairying. Although it has occasionally been adopted else- 

 where, it can hardly be said to be used in any other countries, 

 except, incidentally, in scattered creameries. It is rarely used 

 elsewhere in ordinary dairying, although resorted to occasion- 

 ally for the purpose of remedying butter " faults." 



In the United States the use of pure cultures for cream- 

 ripening has had a somewhat different history. It was intro- 

 duced to dairymen shortly after its development in Copen- 

 hagen ; but for some time little attention was paid to it, so 

 that it was hardly brought to the notice of the ordinary butter- 

 maker. Our butter-makers have not been in condition to 

 pasteurize their cream. For pasteurization there is needed 

 special apparatus^ and the process involves considerable ex- 

 pense. For this reason the method as suggested in Copen- 

 hagen was not very feasible in this country. About five years 

 ago a slight change was made in the process. In order to 

 bring the subject more widely to the attention of dairymen, 

 our butter-makers were advised to use the cultures without 

 previously pasteurizing the cream. This, of course, is an illog- 

 ical method, since the cream is already filled with bacteria, and 

 the addition of a new culture could hardly be supposed to give 

 entirely satisfactory results. With this change in the method 

 of the use of pure cultures, our butter-makers were willing to 

 try them, and in a short time American butter-makers learned 



