120 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 o 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 

 been 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- 



