Calculation of Butter- and Cheese Yield. 191 



The example gives an extreme case, and one not likely 

 to be met with in practice. The range of the richness of 

 the milk delivered by different patrons at the factory is 

 usually within one-half or one per cent, of fat. In such 

 cases the proportion cf fat lost in skimming does not 

 vary much, e. g., in case of milk containing 3.5 and 4.0 

 per cent, of fat, and variations in the overrun occurring 

 when the proper care in skimming, ripening and churn- 

 ing is taken, are due, therefore, primarily to differences 

 in the water and salt contents of the butter made (204). 



216. The losses from poor, rich and average milk, as 

 received at creameries and cheese factories, can be traced 

 from the following statement ; this gives the quantities 

 of fat lost in' handling milk of four grades, viz. : 2.5, 

 3.5, 4.0 and 6.0 per cent., in case of each grade calcu- 

 lated to a standard of 100 Ibs. of fat in the milk. 



To supply 100 Ibs. of fat would require the following 

 amounts cf the different grades of milk: 



4000 Ibs. of milk testing 2.5 per cent, will contain 100 Ibs. of fat. 



2857 " " " 3.5 " . " " 100 <4 " " 



2500 " " " 4.0 " " " 100 " " " 



1666 " " il 6.0 " " " 100 " " " 



Assuming that the skim milk contains .1 per cent, of 

 fat and makes up 85 per cent, of the whole milk, and 

 that the butter milk tests .3 per cent., and forms 10 

 per cent, of the whole milk, the butter-fat record of 

 the quantities of different grades of milk containing 100 

 Ibs. of fat will be as given in the following table. Cer- 

 tain mechanical losses are unavoidable in the cream- 

 ery, as in all other factory operations, viz., milk and 

 cream remaining in vats and separators, butter sticking 



