CHAPTER XII. 

 CALCULATION OF BUTTER- AND CHEESE VIELD 



A. CALCULATION OF YIELD OF BUTTER. 



212. Butter-fat test and yield of butter. The Bab- 

 cock test shows the amount of pure butter fat contained 

 in a sample of milk, cream or other dairy products. 

 The butter obtained by churning cream or milk con- 

 tains, in addition to pure butter fat, a certain amount 

 of water, salt and curd. While an accurate milk test 

 gives the total quantity of butter fat found in the sam- 

 ple of milk or cream tested, the churn cannot be de- 

 pended upon either to leave the same amount of butter 

 fat in the butter milk or to include the same amount of 

 water, salt and curd in the butter at each churning. 



If a quantity of milk, say 3,000 Ibs., be thoroughly 

 mixed in a vat, and then divided into half a dozen equal 

 portions, a Babcock test of the different lots will show 

 the same percentage of butter fat in each portion. If, 

 on the other hand, each of these lots be skimmed, and 

 the cream ripened in different vats and churned sepa- 

 rately, the same weight of butter from each lot of 500 

 Ibs. of milk will not be obtained, even by the most expert 

 butter maker, or if all the operations of skimming, cream 

 ripening, churning, salting and butter-working were 

 made as nearly uniform as possible. Careful operators 

 can handle the milk and cream so that very nearly the 

 same proportion of fat contained in the milk is re- 



