DAIRY LABORATORY GUIDE 



95 



Not all butter analyzes the same. The proportions of the 

 several constituents vary, depending upon the condition of 

 the fat, the efficiency of the apparatus used, and the skill of 

 the maker. The water, of course, varies the most. Water 

 in butter, however, must not exceed 16%. 



/ Pound 



gutter 



Fig. 14. A graphic explanation of overrun. 



A hundred pounds of 30% cream contains 30 Ibs. of 

 butter-fat. In churning not all the fat can be recovered, but 

 the loss with proper methods and appliances is very small. 

 One should make from the 30 Ibs. of fat about 36 Ibs. of but- 

 ter of the composition as given. To calculate the per- 

 centage of overrun, subtract the weight of butter-fat from the 

 weight of the butter and then divide the difference by the 

 weight of butter-fat and multiply by 100. 



Formula : 



Wt. of butter wt. of B.F. 



x 100 = percentage of O. R. 



weight of B.F. 



