DAIRY PRODUCTS 377 



thoroughly ; it can be made of any richness desired ; and 

 the skim milk may be fed to calves or pigs while it is fresh 

 and warm. 



492. Making butter. Cream is usually ripened, or soured, 

 before it is churned. The ripening process consists of allowing 

 cream to sour naturally or by adding sour milk or a commercial 

 starter. 1 Sour, or ripened, cream churns more readily than sweet 

 cream, and the butter keeps longer and has a better flavor. 



FIG. 191. A Babcock testing outfit 



Butter when properly finished is composed of butter fat, water, 

 salt, and a small amount of casein or curd. 



Churning is a process of agitating the cream until the fat 

 globules unite to form butter. The barrel churn (Fig. 189) 

 is the best form of churn. The old dasher churn (Fig. 190) or 

 other churns with inside -fixtures are unsatisfactory because butter 

 made with them has poor body or texture. 



After the cream has been ripened, it should be brought to a 

 temperature of 58 degrees in summer and 65 degrees in winter, 



1 A commercial starter is skim milk soured by adding a pure culture of 

 lactic-acid bacteria. 



