198 PRACTICAL DAIRY BACTERIOLOGY 



THE NEED OF CONTROLLING THE RIPENING 



The butter-maker needs bacteria, but he wants the right 

 kind. The character of the butter obtained from the cream 

 is closely dependent upon the kind of bacteria which develop 

 in it. Many experiments have been performed of making 

 butter from cream ripened with different species of bacteria, 

 which have shown that very different results come from the 

 use of different bacteria. 1 Some species produce unpleasant 

 taints, bad tastes, bitter tastes and other undesirable results; 

 many species have been found to be quite negative in their 

 action on the cream and resulting butter. Other species, again, 

 develop pleasant tastes and odors, and are advantageous and 

 useful in the cream ripening. It chances, fortunately, that the 

 latter is true of most of the lactic acid bacteria. Since in 

 the ordinary bacterial growth in cream the lactic bacteria in 

 the end finally get the upper hand and grow at the expense 

 of all of the others, it commonly happens that the ripening 

 produces a good flavor, and a satisfactory butter is obtained. 

 If this were not true, butter-makers would never have adopted 

 this process of cream ripening, for, of course, ripening has 

 been adopted because it has been found to be commonly suc- 

 cessful in giving a desirable product. Unfortunately, how- 

 ever, the favorable species of lactic bacteria do not always get 

 the upper hand in the cream ripening. It sometimes happens 

 that there are present in cream large numbers of vigorous 

 bacteria just as capable of rapid growth as are the desirable 

 lactic acid germs. In these cases the unusual bacteria may 

 develop abundantly and produce a variety of uncommon changes 

 in the cream, with the result of giving an undesirable flavor 

 to the butter. Such a phenomenon explains the occasional ap- 

 pearance of bad tasting butter. 



1 Conn. Ann. Rep. Storrs Exper. Sta., 1894. 

 Eckles. Cent. f. Bact., II., iv., p. 730, 1898. 



