256 Elementary Principles of Agriculture 



animal odor should be removed by thoroughly airing 

 and cooling the milk. 



365. Churning. The size, consistency and number 

 of the butter-fat globules is not always the same. The 

 object of churning is to cause these many, minute fat 

 globules to unite to form larger ones. This is brought 

 about by agitating the milk in such a way that the 

 globules will rub against each other and unite. As 

 temperature greatly affects the consistency of the 

 globules it also affects the nature of the result in churn- 

 ing. If the temperature is very low, the globules are 

 hard and are less likely to adhere in the operation of 

 churning. If the temperature is very high, it renders 

 the globules quite soft and churning has a tendency to 

 cause them to break up into even smaller particles. 

 There are many other conditions besides the tempera- 

 ture that affect the "gathering," or "breaking," of the 

 butter-fat globules and the character or quality of 

 the butter, such as the condition and breed of the cows, 

 the feed of the cows, the temperature maintained dur- 

 ing the ripening of the cream, the acidity of the cream 

 and even the nature of the agitation given the cream 

 in churning. As these conditions vary, so will the churn- 

 ing temperature. Practical dairymen usually try to main- 

 tain a temperature near 59 to 65 degrees in churning. 

 The preference is usually for the lower temperatures be- 

 cause of the better quality of the butter, although it will 

 require a longer time to churn. There are many styles of 

 churns on the market, but expert butter-makers usually 

 prefer some form of revolving box or barrel churn, claim- 

 ing that it gives a butter with better quality. Where the 

 agitation is produced by paddles the grain of the butter 

 is not so desirable as in the open-centered churns. 



