76 Milk and Its Products. 
in regard to the animal, milker and utensils, milk 
may be secured with a minimum number of bacteria. 
The difference in the number of bacteria in milk so 
drawn, and in milk carelessly drawn, may easily 
amount to a difference of eighteen to twenty-four 
hours in keeping quality under like conditions. 
Holding at low temperatures. —If milk be immedi- 
ately cooled to a temperature of 40° F., or thereabouts, 
very little fermentation will go on, though it will be 
frequently found that after three or four days the 
milk or cream may have a more or less disagreeable 
flavor, due to the presence of some germs that de- 
velop slowly even at low temperatures. If low tem- 
peratures are to be depended upon as a means of 
keeping fermentations in check, it is, of course, of 
prime importance that every precaution should have 
heen taken to prevent the access of germs to the 
milk in the first place. The fewer germs the milk 
contains to begin with, the more effective will low 
temperatures be as a means of preservation. With 
care in both these respects, milk or cream may be 
kept in a fresh and merchantable condition for a 
week or ten days. 
Destruction of germs in the milk.—A large number 
of chemical agents is more or less destructive to 
germ life. Many of them are so violent in their 
action as to destroy the milk as well as the germs, 
but there are many which are destructive to germ 
life, with no effect upon the composition, odor or 
flavor of the milk; but all of these without excep- 
tion are more or less injurious to the human sys- 
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