Ripened Cream 405 



play an important part in the ripening process is evi- 

 denced by their presence in such truly enormous num- 

 bers. According to Conn, normally ripened cream con- 

 tains 100,000,000 to 1,500,000,000 of bacteria per cubic 

 centimeter, the average number being about 500,000,000. 

 The organisms grow rapidly at the temperature of ripen- 

 ing cream and produce the changes that subsequently 

 modify the flavor and probably also the keeping quality 

 of the butter. 



In cream, as in milk, the various kinds of bacteria 

 must compete for their food. Only those best adapted 

 to their environment finally emerge victorious from the 

 struggle. We have already seen that in milk the lactic- 

 acid bacteria, largely on account of the lactic-acid pro- 

 duced by them, usually gain the upper hand and pre- 

 vent the growth of the other species. We have seen, also, 

 that there is more or less associative action in the bac- 

 terial decomposition of milk, for the lactic-acid germs 

 are evidently stimulated in their development by the 

 changes caused by some of the other species. 



Similar conditions prevail in cream. While it is still 

 sweet, the peptonizing bacteria grow freely, decompose 

 the protein substances and prepare the ground for the 

 lactic-acid germs. These, in their turn, become more and 

 more prominent, and, finally, crowd out the other 

 species. As a result of the activities of the two groups 

 of organisms, we have an accumulation of protein de- 

 composition products on the one hand, and of lactic 

 acid on the other. These substances impart distinct 

 tastes and flavors to the cream and to the butter made 

 from the cream. 



