CHAPTER XIII. 

 BACTERIA IN BUTTER AND OLEOMARGARINE. 



BACTERIA IN BUTTER-MAKING. 



In the making of butter, bacteria are the dairyman's allies. The 

 butter-maker always, even though unconsciously, makes direct use 

 of bacteria when he subjects his cream to a process almost univer- 

 sally adopted in butter-making, called ripening, or, in Europe, 

 more commonly called souring. In butter-making, the cream is 

 not usually churned immediately after it is separated from the milk, 

 but it is allowed to lie in a moderately warm vat for a period of twelve 

 to twenty-four hours or even longer, that it may ripen. In some 

 places there is a demand for what is known as sweet cream butter, 

 which is simply butter made from fresh cream without ripening; 

 but such a demand is very limited, and most butter is made from 

 ripened cream. 



CREAM-RIPENING. 



The custom of ripening cream is an old one, doubtless as old 

 as the process of butter-making. Upon a farm where the amount 

 of cream is small, it is always necessary to allow it to accumulate 

 for some days till there is sufficient for a proper churning. During 

 this period it is sure to undergo ripening without any intention on 

 the part of the farmer. On ordinary farms, the cream is left to take 

 care of itself, and is thus sure to be ripened by the time there is 

 enough to churn. But the centralization of butter-making into 

 creameries, where large quantities of cream are handled daily, has 

 put a new aspect upon the problem. The ripening will no longer 

 care for itself, but must be carefully attended to by the butter-maker. 

 The necessity for some accurate means of controlling the ripening 



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