BUTTER 



Butter is milk-fat from which the greater part of the milk 

 plasma has been removed by a process of agitation known as 

 churning. The clumps of fat globules in butter retain their gen- 

 eral physical condition, although this is true only of butter of normal 

 quality. The texture of butter may vary, but is especially depend- 

 ent upon the temperature at which churning is carried on. If a high 

 temperature is employed the fat softens or even melts, and a greasy 

 product is churned. On the other hand, if a low temperature is 

 used a butter of firm consistency is churned. Milk-fat contain- 

 ing relatively large amounts of olein produces a soft butter. It is 

 beheved that the food a cow consimaes greatly influences the con- 

 sistency of butter-fat. While food rich in vegetable oils produces 

 a milk-fat rich in olein, dry fodder and that containing much starch 

 produces a hard fat. The size of the fat globules is also said to 

 influence the condition of butter, inasmuch as large globules are 

 supposed to furnish a butter of soft texture, while small globules 

 have the opposite effect. 



While a high temperature facilitates the separation of butter 

 from cream, due largely to the reduced viscosity, a good butter 

 maker always keeps the temperature of churning below the melt- 

 ing-point of butter-fat. As this point is not the same in all butter- 

 fats, the most suitable temperature for churning varies somewhat. 

 It is usually stated that it should not be below 50° F. nor above 

 65° F. 



The rapidity and completeness of separation of butter-fat 

 from the cream depends upon several factors. Temperature is 

 of importance in this respect, as a high temperature permits 

 easier and more complete separation of fat than does a low one. 

 The cause of this difference is probably ascribable to the effect of / 

 temperature on the viscosity. A second factor of importance is 

 the size of the fat globules. The larger they are, the more readily 

 can they be separated. Jersey milk, with its large globules, churns 

 easier than does Holstein milk; milk derived from a cow in the 

 early stages of lactation is more churnable than that from later 

 stages; homogenized milk is always difficult to churn and the fat 

 is removed incompletely. 



Rich cream churns more easily than lean cream because in 

 the former the fat globules are close together. In sour cream 

 the viscosity is greatly reduced, and consequently the fat sep- 

 arates more easily than from sweet cream, and the yield is greater. 



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