57 



butter ot the very highest quality. In the light of the present experi- 

 ments, therefore, it appears that ali grades of butter may be somewhat 

 improved by the use of artificial cultures. 



Another matter of some interest is the fact that Bacillus No. 41 is 

 not a milk souring organism. The " ripening " of cream is in many 

 places called the " souring " of cream, and it has been supposed by all 

 experimenters hitherto that the souring was identical with the ripening. 

 For this reason all of the species of bacteria which have hitherto been 

 used in ripening cream have been acid producing organisms. Experi- 

 menters have not thought it worth while to investigate whether or not 

 the aroma of butter might not be due to species of organisms that do 

 not normally sour the cream. Bacillus No. 41, while it produces a very 

 slight acid reaction, does not sour cream, and it belongs therefore, to 

 an entirely different class of organism Irom those hitherto used. This 

 is especially interesting as indicating that probably the aroma of the 

 butter is entirely distinct from the souring of the cream and mav be 

 produced either by acid organisms or by organisms that do not produce 

 acid. 



In one other respect Bacillus No. 41 appears to show itself as de- 

 cidedly more advantageous in practical use than the organisms hitherto 

 used. As will be seen above no previous treatment of the cream is 

 needed in order that Bacillus No. 41 may produce its appropriate re- 

 sults. This of course, greatly simplifies the use of the organism and 

 makes it much more probable that artificial inoculation of cream for 

 ripening may in the future become a somewhat universal pro- 

 cess. So long as butter-makers are obliged to heat their cream 

 before artificial inoculation, in order to destroy bacteria already 

 present in it, so long will they hesitate about adopting any form of artifi- 

 ca! inoculation. When however, the butter can be improved from 

 three to eighteen points by the simple addition of the culture of the 

 proper species, the use of the organism becomes decidedly easier. When 

 first undertaking these experiments, 1 was extremely incredulous as to 

 the likelihood that artificial ripening of cream would ever be very com- 

 mon anions butter-makers. Having, however, seen what good results can 

 accrue to all grades of butter by the simple addition of a culture to the 

 cream, 1 am now prepared to believe that the artificial ripening of 

 cream will have a growing popularity among the butter-makers of this 

 country. 



