BACTERIA IN MILK. 83 



directly into a sterilized bottle which is then quickly 

 stoppered with a sterilized cork. Examination of cultures put 

 up in this way and held for periods of six months to one year, 

 fail to reveal any but the original organisms introduced, which 

 is in distinct contrast to cultures put up in the powder form 

 where they must necessarily be exposed to the air sooner or 

 later and thus become contaminated with foreign and some- 

 times harmful micro-organisms. 



SUMMARY. 



i. Milk in its natural state is free from bacteria and conse- 

 quently will keep indefinitely. 



Fore-milk contains a few bacteria and should be rejected. 



Milk is seeded with bacteria from dust, contact with im- 

 properly cleaned utensils, water, etc. 



Bacterial analyses of milk may be depended upon to indi- 

 cate the care with which it has been previously handled. 



A large part of the milk analyzeds hows it to have had 

 proper care. 



Cooling milk does not entirely prevent growth of bacteria, 

 but prevents souring. 



The cans of the local dealers into which milk is put add a 

 considerable number of bacteria to the milk. 



A bacterial examination of dairies is a valuable assistance 

 in improving the condition of a milk supply. 



Question — Does pasteurization improve milk and cream for 

 butter-making ? 



Answer — In many ways butter made from pasteurized 

 cream is preferable to that made from raw cream. This is espe- 

 cially true for butter intended for storage or shipment to dis- 

 tant points, as the keeping qualities derived from pasteuriza- 

 tion are such that the butter undergoes but little change for some 

 time. The flavor of the butter made in this way is usually not 

 so pronounced and fragrant as with the raw cream product and 

 for that reason does not perhaps suit the home market demand 

 as well, yet in the long run a much more uniform and higher 

 grade article is produced. 



It has been alleged by some that the grain or texture of 

 the butter is somewhat injured by pasteurization. Whether this 

 is so or not I am not in a position to say, but the chief draw- 

 back to its more general adoption seems to be that what is 

 gained by the process does not compensate for the extra ex- 

 pense and trouble incurred. 



