RECEIVING. SAMPLING, AND GRADING. 89 
thoroughly. The remedy is to use more acid, or to warm milk 
- and acid before mixing, or to shake the mixture thoroughly 
before whirling. (3) Occasionally there is a layer of impure 
foam at the top of the fat column. This is gencrally due 
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Fic, “athe cit churn, 
to the use of hard and impure water. The remedy is to use 
pure distilled hot water. For more detailed information on 
this subject see ‘Testing Milk and its Products,” by Farrington 
and Woll. 
Necessity of Good Milk.—All authorities agree that the best 
grade of butter and cheese cannot be made from sour or tainted 
milk. The two countries renowned for the excellence of their 
