CHAPTER X. 
CREAMING. 
Cause. Creaming is due to the difference in the speci- 
fic gravity of the fat and the milk serum. The fat being 
light and insoluble rises, carrying with it some of the 
other constituents of the milk. The result is a layer of 
cream at the surface. 
Processes of Creaming. The processes by which milk 
is creamed may be divided into two general classes: (1) 
That in which milk is placed in shallow pans or long 
narrow cans and allowed to set for about twenty-four 
hours, a process known as natural or gravity creaming; 
(2) that in which gravity is aided by subjecting the milk 
to centrifugal force, a process known as centrifugal 
creaming. The centrifugal force has the effect of increas- 
ing the force of gravity many thousands of times, thus 
causing an almost instantaneous creaming. This force 
is generated in the cream separator. 
Shallow-Pan Method. ‘The best results with this 
method are secured by straining the milk directly after 
milking into tin pans about twelve inches in diameter 
and two to four inches deep. It is then allowed to remain 
undisturbed at room temperature (60° to 65° F.) for 
twenty-four to thirty-six hours, after which the cream is 
removed either with a nearly flat, perforated skimmer, or 
by allowing it to glide over the edge of the pan after it 
has been carefully loosened along the sides. The aver- 
age loss of fat in the skim milk by this method is 0.7%. 
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