CRBAMERY BUTTER MAKING 103 



time. It is better, however, to avoid an excessive richness 

 when an exhaustive churning is to be expected. 



5. Amount of Cream in Churn. The best and quick- 

 est churning is secured when the cliurn is one-third full. 

 With more or less cream than this the amount of concus- 

 sion is reduced and the length of time in churning cor- 

 respondingly increased. 



6. Speed of Churn. The speed of the churn should 

 be such as to produce the greatest possible agitation or 

 concussion of the cream. Too high or too low a speed 

 reduces the amount of concussion. The proper speed for 

 each particular churn must be determined by experiment. 



7. Abnormal Fermentations. The slimy or ropy fer- 

 mentation sometimes causes trouble in churning by ren- 

 dering the cream excessively viscous. Cream from single 

 herds may become so viscous as to render churning im- 

 possible. At creameries where milk is received from many 

 herds very little trouble is experienced from these fer- 

 mentations. 



CHURNS. 



A churn is a machine in which the cream is made 

 to slide or drop, or is in some way agitated to bring about 

 the union of the fat globules, which changes the liquid fat 

 into a solid. For many years the factory churns had 

 assumed the form of a box or barrel free from any inside 

 fixtures. Such churns were revolved by power and did 

 very satisfactory work. But it was necessary to transfer 

 the butter, after it was churned, to a worker upon which 

 it was worked. 



This transfer from one piece of apparatus to another 

 was obviated bv the invention of "combined" churns and 



