238 MODERN DAIRY PRACTICE. 



worked early in the morning before it is perfectly light. 

 This custom ought not to be followed, for it is impossible 

 to observe the necessary cleanliness in semi-darkness, and 

 to make the necessary and accurate observations without 

 which a good churning and working cannot be accom- 

 plished. The work should take place in full daylight from 

 beginning to end; if the creamery-work thereby extend 

 somewhat later it cannot be helped. 



The butter can lose its keeping quality already in the 

 churn above all by the application of a wrong churning 

 temperature, so that it cannot be properly freed from the 

 buttermilk. The butter granules should remain separate 

 and clear at the end of the churning, and the buttermilk 

 easily drain from the butter. 



When the butter has come all operations aim at the 

 complete removal of the buttermilk particles from the 

 butter. As shown by Duclaux, pure butter fat is not a 

 nutritive medium for the bacteria; but besides fat, butter 

 contains both air and water, as well as buttermilk, with its 

 ash materials and albuminoid substance. It is from the 

 albuminoids (casein, albumen, etc.) that danger of spoiling 

 threatens, for they are especially readily attacked by bac- 

 teria and furnish them with the necessary nutrients. The 

 importance of diminishing the quantity of buttermilk 

 present in the butter is therefore evident; it would doubt- 

 less increase the keeping quality of the butter if the butter- 

 milk could be entirely removed, but the butter would then 

 lose its peculiar flavor and become fat pure and simple. 



The importance of a small bacteria content of the 

 buttermilk also follows from what has been said. It is 

 intimately mixed with the butter, and forms a favorable 

 breeding-place for the fermentation bacteria dangerous to 



