MISCELLANEOUS SUBJECTS 67 



of cheese for 100 pounds of milk. The theoretical 

 yield is reduced by the losses in the cheese-making 

 operations, due (i) to evaporation of water and 

 (2) to mechanical losses. The yield of whey varies 

 with the composition of the milk and, therefore, 

 with the time of season and other conditions that 

 affect the composition of milk (p. 204). In gen- 

 eral, it is safe to say that the yield of whey is about 

 88 pounds for 100 pounds of milk, taking the sea- 

 son as a whole; but this yield is considerably 

 reduced by losses in handling. In allowing each 

 patron to take the portion of whey coming to him, 

 the usual amount is 80 to 85 pounds for 100 pounds 

 of milk delivered. Where the whey is valued by 

 every patron, it is essential that each one be as- 

 signed his just portion ; otherwise some will always 

 take more than belongs to them. There are various 

 satisfactory devices for controlling the amount of 

 whey each patron can take. 



The chief value of whey to patrons is as material 

 for feeding pigs and calves in connection with 

 other foods. The feeding value of sweet whey 

 may be conservatively placed at 8 to 10 cents for 

 100 pounds. For the composition of whey, see 

 p. 197. Whey sours rapidly and loses a consider- 

 able amount of its milk-sugar under ordinary con- 

 ditions. In order that its highest food value >may 

 be realized, it is essential that it should be pasteur- 

 ized promptly at 155 to 158 F. and the whey- vat 

 always kept in clean condition (p. 127). It is not prac- 

 ticable to sterilize whey, because the heat needed for 

 sterilization coagulates the albumin. Whey that is de- 

 cidedly sour often has an injurious effect on the animals 



