CONDENSED BUTTERMILK 185 



whey into a kettle or large open pan over a fire. ^Thc albumi- 

 nous material that precipitates and rises to the surface is skim- 

 med off." 1 The whey is evaporated as rapidly as possible with 

 constant and thorough stirring. When it has reached about one- 

 fourth of its original volume the albumin previously skimmed 

 off is returned and stirred thoroughly to break up all possible 

 lumps. When the whey has attained the consistency of thick- 

 ened milk it is poured quickly into a wooden trough and stirred 

 with a paddle until cool, to prevent the formation of large sugar 

 crystals. Tt can then be molded into the desired form for 

 market. 



A more rapid method of making primost is to evaporate the 

 whey in the vacuum pan. When the syrup has reached the 

 desired density it is drawn off, allowed to cool and pressed into 

 bricks. The product has a yellowish-brown color, gritty texture 

 and sweetish taste. The evaporation of whey in vacuo is as yet 

 a rare practice and the demand for the finished product is very 

 limited. 



Experiments with the "Continuous Concentrator" have 

 demonstrated that condensed whey of good quality can readily 

 be prepared with this machine. The concentration can be car- 

 ried as far as 15 to 1 ; whey so condensed escapes from the con- 

 centrator still in liquid form, but changes to a solid upon cool- 

 ing, the milk sugar in this supersaturated solution crystallizing 

 completely. If made of sour whey, the product thus obtained 

 has a splendid clean and sharp acid flavor. This product prom- 

 ises to have excellent dietetic properties, and also to lend itself 

 admirably for cooking purposes. 



1 United States Department of Agriculture, Bureau of Animal Industry, 

 Bulletin No. 105. 



