2O2 BACTERIA IN BUTTER. 



threat to the very existence of the dairy industry. This 

 disease has been distributed over the country by the agency of 

 the central collecting stations. A creamery receiving milk 

 from a wide territory will return skimmed milk to the various 

 farms. No farmer, however, receives back the skimmed milk 

 of his own farm, but an equivalent amount of skimmed milk 

 from the same creamery. If there chances to be any tubercu- 

 losis in the neighborhood the infected tuberculous milk will 

 be widely distributed over the territory from the creamery. 

 It is the general belief that this has been one of the chief 

 sources of distribution of this disease. To meet this danger 

 regulations recently passed require that all milk and cream 

 which is brought to a creamery shall be pasteurized at a 

 sufficient temperature before it is returned to the farmers. 

 Thus forced to pasteurize their cream the butter-makers are 

 also forced to use starters, since the cream, after pasteurizing, 

 will not ripen normally without them. For this purpose they 

 find commercial cultures most convenient and Denmark now 

 almost universally adopts the use of pure cultures for the 

 ripening of cream. 



The Use of Starters in Unpasteurized Cream. Pasteuriz- 

 ing cream, which is the essence of the method described, has 

 not been very generally adopted by the butter-makers in 

 America, nor, indeed, has it as yet been very widely adopted 

 by butter-makers outside of northern Europe. Pasteuriza- 

 tion is a matter that requires considerable time, trouble and 

 expense. To heat several hundred gallons of cream to a 

 temperature of 160, and then to cool it rapidly, so as to 

 inoculate it subsequently with pure cultures, is a procedure 

 which involves considerable extra work, and butter-makers 

 hesitate about adopting it unless they see good reason for 

 doing so. The use of pure cultures which depends upon 

 such pasteurization has for this reason not extended widely 

 among butter-making countries. 



