270 CHURNING 



volving churn, the increased power of adhesion enables the 

 partly or wholly solidified fat globules to unite, forming butter 

 granules. 



Increase in Size of Butter Granules. This union of fat 

 globules and formation of butter granules proceeds in geometric 

 progression. While it commences as soon as the churn starts 

 revolving, the process of uniting at first is slow and the change 

 is imperceptible. The minute size of the fat globules retards 

 their opportunity for collision with and adhesion to one-another 

 and the butter granules resulting from these early adhesions 

 are microscopic in size. The average fat globule measures about 

 3/1000 of one millimeter or about 1/10,000 of one inch in diam- 

 eter. The sum of two fat globules forming one butter granule, 

 therefore, also is extremely small. But, as the churning process 

 progresses, the butter granules form more rapidly and grow 

 in size more rapidly. The larger they grow the more rapidly 

 they increase in size with each successive adhesion. 



Why Cream Thickens in the Churn. As the churning 

 process proceeds, the cream begins to thicken and continues to 

 thicken, until it assumes marked rigidity, practically assuming 

 maintenance of form. This thickening is due in part to the 

 increased size of the still microscopic or semi-microscopic but- 

 ter granules. These larger granules offer more internal friction 

 and hold the serum in a mash-like emulsion. Up to a certain 

 point, the larger these microscopic granules the thicker and 

 more rigid the cream. 



The thickening of the cream during the early part of the 

 churning process is also due, in a large measure, to the profuse 

 incorporation of air in this viscous, cold cream. The cream 

 whips. The air so incorporated and the rigid character of the 

 cream which the minutely divided air helps to bring about, 

 have a very marked retarding effect on the churning process, 

 greatly minimizing the concussion to which the fat globules are 

 subjected, and making it difficult for them to find each other 

 and to strike each other with sufficient force to coalesce to one 



