CHAPTER XXV. 



WHEY BUTTER. 



IN the manufacture of all kinds of cheese whey is a by- 

 product. It is commonly returned to the farmers and fed 

 to hogs, but in some cases valuable products are recovered 

 from it. The composition of whey is fairly constant, 

 except that the fat content varies between wide limits. 

 The average composition of whey is about as follows: 



Per cent. 



Water 93.0 



Sugar 5.0 



Albumen 0.7 



Fat 0.3 



Casein 0.3 



Ash 0.7 



The largest percentage of solid matter in whey is milk 

 sugar, the recovery of which will be described in a subse- 

 quent chapter. 



The solids remaining in whey are sometimes recovered 

 by heating or evaporating the water, the residue being 

 made into a kind of cheese (mysost). The main constit- 

 uent of this cheese is milk sugar, which is in marked con- 

 trast to all our common varieties of cheese, the principal 

 constituents of which latter are casein and fat. 



The milk solid in the whey that may be most easily re- 

 covered is the fat. In cheddar-cheese making the quantity 

 of fat left in the whey seldom exceeds 0.3 per cent, and may 

 be only one-third this much. In the manufacture of Swiss 

 cheese the whey contains from 0.7 to i per cent of fat. 



