CHAPTER XI 
CHURNING 
THE process of causing the particles of butter fat 
to unite into masses, so that they may readily be 
separated from the milk serum, is called churning. 
Such union of the particles of fat is ordinarily 
brought about by agitation of the cream in a suit- 
able vessel, called a churn. If milk or cream be 
agitated at a temperature somewhat below the melt- 
ing point “of butter fat, the particles of fat, as they 
pass by one another, agglutinate themselves into 
masses, and, the process being continued, the first 
formed masses continue uniting, until finally the 
whole body of fat may be brought together in a prac- 
tically solid mass. The conditions influencing the 
separation of fat in this way are, first, the viscosity 
of the milk; second, the ripeness of the cream; 
third, the temperature; fourth, the nature of the 
agitation; fifth, the quality of the globules of fat. 
The viscosity of the milk.— The viscosity of the 
milk affects the churning, in that it tends to keep 
the particles of fat from moving freely upon one 
another, and in that the viscous portions of the 
milk, notably some of the albuminous matter, form a 
more or less dense layer about the fat globules. 
" (210) 
