CREAMERY BUTTER MAKING 155 



determine the effect of sudden heating of cold milk on the 

 loss of fat in the skim-milk. It is well known that the 

 exhaustiveness of skimming with any separator is greatly 

 influenced by the manner in which the milk is heated. In 

 general very sudden heating has the effect of diminishing 

 the difference in the specific gravity between the fat and 

 milk serum, consequently rendering the separation of the 

 fat from the milk more difficult. 



In our experiments we found that in many instances 

 where the milk was received in a partly frozen condition 

 and suddenly heated to a separating temperature of 80 

 to 85 F., the loss of fat in the skim-milk was from .08% 

 to .12%. When, however, such milk was suddenly heated 

 to a temperature of 160 F. or above the loss of fat in the 

 skim-milk was from .02% to .03%. 



b. Eliminating Weedy Flavors. In our experience 

 nothing has been found so effective in eliminating bad 

 odors from milk as the separation of same at high tem- 

 peratures. High temperatures in themselves have a tend- 

 ency to evolve from milk undesirable odors so frequently 

 present, especially during the weedy season. When the 

 high temperature is assisted by the whirling motion to 

 which milk is subjected in a cream separator, the power 

 of eliminating odors is increased. This can readily be 

 proved by carefully examining the air or gases that issue 

 from the cream and skim-milk spouts. 



c. Destroys Bacteria. Pasteurizers are placed upon 

 the market as bacteria destroyers. In our experiments 

 with the Reid machine no bacteriological tests were 

 made. Repeated scoring of the butter showed, however, 

 that when ordinary milk was used the quality was im- 

 proved from two to four points by pasteurizing. 



Bacteriological tests with the Reid pasteurizer are re- 



