CHAPTER XIX. 



DETECTION OF TAINTED OR IMPURE MILK. 



In well regulated creameries the head butter maker 

 will usually be found at the intake every morning care- 

 fully examining the milk as it arrives at the factory. It 

 requires skill and training to detect and properly locate 

 the numerous taints to which milk is heir. It also requires 

 considerable tact to reform patrons who have been care- 

 less in the handling of their milk. The best skill available 

 in the creamery should therefore be placed in the intake. 



In the daily examination of milk, defects can usually be 

 detected by smelling of it as soon as the cover is re- 

 moved from the cans. When, however, milk arrives at 

 the creamery at a temperature of 50 F. or below, it 

 becomes more difficult to detect taints ; indeed during the 

 winter when milk is often received in a partly frozen 

 condition, experts may be unable to detect faults which 

 become quite prominent when the milk is heated to a 

 temperature of 100 F. or above. 



Frequently milk is seeded with undesirable kinds of 

 bacteria which have not had time to develop sufficiently 

 to manifest themselves at the time the milk is delivered 

 to the creamery, but which later in the course of cream 

 ripening produce undesirable flavors. It is necessary, 

 therefore, in making a thorough examination of milk to 

 heat it to a temperature of from 95 to 100 F. and to 

 keep it there for some time to permit a vigorous bacterial 

 development. Such bacterial development is best carried 

 on in what is known as the Wisconsin Curd Test, a full 

 description of which is given below. 



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