BACTERIA AND BUTTER-MAKING 199 



When butter was made upon the small farm the occasional 

 appearance of an improper ripening was a matter of no very 

 great importance. The butter is rarely so bad that it cannot 

 be eaten, and the farmer who made his own butter did not 

 particularly trouble himself if, for a few days, or even for a 

 few weeks, his butter had a stronger taste than usual. When, 

 however, butter came to be made in creameries, the necessity 

 for producing a uniform product was greater. When a cream- 

 ery is producing hundreds of pounds of butter per day, and 

 when the market price will depend upon the character of the 

 butter, it is a matter of more importance to obtain a desirable 

 flavor. A good flavored butter will yield a high price, and 

 poorly flavored butter will inevitably yield a lower price. 

 Under these circumstances, the question of financial failure or 

 success may hinge upon flavor, and this in itself depends upon 

 the ripening of the cream. Hence, in recent years all cream- 

 eries have come to recognize the vital importance of a proper 

 control over the ripening. Inasmuch as this ripening is a bac- 

 terial problem it follows that the success of a creamery is, to a 

 large extent, dependent upon the control of its bacteria. 



Flavor and Aroma. The general character of the butter is 

 determined by both flavor and aroma. The term flavor refers 

 to the taste of the butter, whereas the term aroma refers rather 

 to the smell. These two factors do not appear to be the same, 

 and in some cases, at least, they have a different origin. Some 

 bacteria give rise to a desirable flavor in butter but do not give 

 rise to an aroma; others give rise to an aroma without much 

 flavor; and different species still produce neither acid, flavor 

 nor aroma. 1 It is not understood from what materials the 

 flavors and aromas are produced. 2 That they are not caused 

 by the acid in the cream alone has already been mentioned. 

 They are not due primarily to the fat, as is shown by the fact 

 that they will appear in ripened skim milk. 3 That they are 



1 Conn. Ann. Rep. Storrs Exper. Sta. 1894. 



- Weigmann. Milchztg., p. 193, 1897. 



3 Mickels. 22d Ann. Rep. Wis. Exper. Sta., 1905. 



