216 Milk and Its Products 
the hardness or softness of the fat. The relative 
proportions of hard and soft fats vary consider- 
ably. When the soft fats 
predomirate, the churning is 
easier than when they are in 
less proportion, while an uwun- 
due proportion of hard fats 
often renders churning ex- 
tremely difficult. The size of 
the fat globules also bears an 
important part in the ease 
and time required for churn- 
ing. In passing through a 
mass of liquid two large globules are more likely 
to hit each other than are two small ones, the rela- 
tive probability of their meeting and hitting being 
in proportion to the squares of their diameters. , 
The end of churning.—When the particles of fat 
have united to such an extent that they begin to be 
visible in the cream, the butter is said to “break,” 
and from this time on the process of churning is rap- 
idly finished. Two things are to be observed in bring- 
ing the operation of churning to a close. In_ the 
first place, the churning should be continued until 
the separation of fat is as complete as_ possible. 
In the second place, the larger the masses of but- 
ter in the churning the more difficult is the re- 
moval of the buttermilk. If the cream is thor- 
oughly and uniformly ripened, the separation will be 
more uniform and the churning more complete 
than when creams of different degrees of ripeness 
Fig. 35. “Simplex” combined 
churn and butter worker. 
