SO.MI'. OF THK CAUSES AND THKIR PREVEXTIOX 325 



long time at high temperatures. When butter is deteriorating 

 very rapidly in quality it usually reaches the stage where it has a 

 pronounced cheesy flavor, which later on changes to what might 

 be described as a turjientine flavor. Butter of this character will 

 usually sell in the markets as " Seconds." Cheesy fla\'or is said 

 to be due to decomposition of the curdy matter in butter. 



Sour Flavor. — Sour flavor is sometimes caused by over- 

 ripening the cream at the creamer)-. The autliors ha\'e seen guod 

 cream from whole milk overripened to such an extent that it 

 produced sour-flavored butter. The churning of cream with 

 high acidit)', without reducing this acidity, will produce sour 

 butter. Butter judges sometimes describe a sour, disagree- 

 able flavor as a dish-rag flavor, because the odor accom- 

 panying it is very much like that given ofl' by an unwashed dish 

 cloth. The use of unclean cloths for cleansing dair}- utensils 

 usually means the transmission of undesirable fla\-ors to milk 

 and cream. For washing utensils a brush is much preferable to a 

 cloth. 



Some creameries that are producing the best butter from 

 shipped cream have a set rule that all cream cans must be thor- 

 oughly cleansed and sterilized before being returned to patrons. 



Harding and Ayers both report that they were able to produce 

 good milk in stables where manure was plentiful, and C(jbwebs 

 were hanging from the ceihng, by sterilizing all dairy utensils 

 that came in contact with the milk or cream. 



Eckles, when connected with the Iowa Experiment Station, 

 isolated Bacillus coli aerogoies, added it to pasteurized skim- 

 milk and made a starter, and added the same to sweet cream 

 for the purpose of ripening or souring it to determine the injurious 

 effect it would have upon the flavor of butter. The quality of 

 the butter produced was not seriously affected by this starter. 

 One of the authors had the privilege of scoring this butter, and, in 

 his judgment, it was good commercial butter, though not as 

 pronounced in fla^'or as butter made from cream ripened by a 

 culture starter. 



Faulty Factory Conditions. — Bad flavors found in milk, cream 

 and butter are sometimes due to conditions prevaihng in the 



