BACTERIA IN IIl'T TKR-MAKING. 245 



butter-makers in all countries that the quality of their butter 

 depends in very large degree upon the character of the ripen- 

 ing, and that this ripening is due to the growth of bacteria in 

 the cream. It has taught them that to insure good butter 

 with uniformity a closer attention must be paid to the ripening 

 and that, during most of the year, perhaps all of the year, the 

 most satisfactory ripening may be best obtained by the use of 

 starters properly prepared. It has taught them that such a 

 starter may easily be made by the butter-maker or it may be 

 purchased. The use of pure cultures, with previous pasteur- 

 ization of the cream, has proved, in northern Europe, of such 

 distinct advantage that it has been adopted universally in Den- 

 mark, and widely in north Germany ; but this method has 

 not seemed to butter-makers in other countries of sufficient 

 value to warrant the trouble and expense. The use of pure 

 cultures has often been found most efficacious in remedying 

 dairy troubles, which produce what are called butter " faults," 

 and it will, in the future, be more widely used for seasons of 

 special trouble in the creamery than it has been in the past. 

 The use of starters of some kind in cream-ripening is almost 

 sure to increase, but, according to the present outlook, the use 

 of pure cultures does not seem likely to become adopted by 

 the butter-makers in the United States. Natural starters ap- 

 pear, on the whole, to be more practical as applied to Amer- 

 ican dairying than commercial cultures. 



BACTERIA IN BUTTER. 



It is of interest to ask what becomes of the enormous num- 

 bers of bacteria which develop in the cream during the ripen- 

 ing, and whether they are subsequently of any significance in 

 the butter. Although these bacteria continue to grow during 

 the ripening period their growth is practically stopped by the 

 churning and butter-making. Many of them are naturally re- 

 moved with the buttermilk ; others are washed away during 



