HEATING MILK PREVIOUS TO SKIMMING. 119 



this country, and perhaps at the present time, is about 90° F. 

 This comparatively low temperature was fixed owing to the 

 supposedly bad effect high skimming temperature had upon 

 the body of the finished butter. Exposing milk, at high tem- 

 peratures, to the centrifugal force in a separator was said 

 to producea greasy body in butter. According to some ex- 

 periments conducted at the Iowa Experiment Station by the 

 authors during the year 1902, milk can be skimmed at 175° F. 

 without any injury to the quality of the butter, providing the 

 cream is cooled to ripening temperature, or below, as soon 

 as it has been skimmed. After the ripening has been com- 

 pleted the cream should be exposed at least three hours to a 

 low temperature (50° F.) previous to churning. 



If the milk is heated in any of the best modern heaters, 

 no injurious results to the quality of the butter will be obtained. 

 Prof. Dean, at the Ontario Agricultural College, has also found 

 it practical to heat to pasteurization temperature previous to 

 skimming. In many creameries in Denmark this method of 

 heating milk is also followed. The Danes, as a rule, however, 

 have the heated milk pass over a cooler before it goes into 

 the separator. 



The chief difficulty encountered by the authors in heating 

 milk to such a high temperature previous to skimming, was 

 that the upper bearing in the separator got so hot that it was 

 deemed injurious to the separator, although the bearing did 

 not heat to such an extent as to cause the running of the 

 machine to be abnormal in any way. 



Advantages of Warming Milk to High Heat Previous ta 

 Skimming. — The advantages of heating milk to a high tem- 

 perature (175° F.) previous to skimming, may be summarized 

 as follows: 



(1) Undesirable taints are eliminated from the milk to a 

 greater extent than can be accomplished in any other way, 

 without applying chemicals. 



(2) The heating of whole milk destroys the germs in the 

 resultant skimmed milk and cream practically as efficiently 



