BACTERIA AND WTTKR-M AKING 195 



of America. Some people are very fond of such mild butter. 

 A demand for sweet cream butter has developed in America; 

 but at the present time this demand is small and forms only a 

 very small part of our butter product. There has been a change 

 in public taste concerning butter during the last 25 years. At 

 present the demand is for a milder flavored butter than a gen- 

 eration or so ago, and a strong, high flavored butter will not 

 find, to-day, as ready a sale as it formerly would. Butter that 

 would formerly have sold readily as first grade would now be 

 regarded as too strong and ranked as second or third quality. 

 Xo doubt there has been, even in the United States, a general 

 tendency for a milder type of butter. Whether this tendency 

 will develop further until our markets demand a large amount 

 of sweet cream butter cannot, of course, be predicted. 



The Cause of Cream Ripening. The ripening of cream is a 

 phenomenon of bacteria growth. The bacteria which are in the 

 cream find it an excellent medium for food, and if kept at a 

 fairly warm temperature during the ripening period, their devel- 

 opment is quite rapid. For the 12 to 24 hours of ripening the 

 bacteria multiply, and by the time the cream is ripened and 

 ready to be churned they are present in prodigious numbers. 

 Many analyses of ripened cream have been made, disclosing 

 the fact that whereas in the sweet cream bacteria may be 2,- 

 000,000 to 3,000,000 per c.c., in the same cream when ready to 

 churn there may be about 500,000,000 per c.c. The numbers at 

 the time of ripening, however, vary widely, being sometimes 

 as low as 200,000,000, or even lower, and sometimes as high as 

 2,000,000,000 per c.c. There does not seem to be any especially 

 close connection between the completeness of the ripening and 

 the number of bacteria. In some thoroughly ripened cream 

 samples there may be two or three times as many bacteria as 

 in others, and yet no difference in the completeness of the 

 ripening can be seen. 



The growth of bacteria in the cream produces critical 



