BUTTER FAULTS. 145 



only undergoes a marked change in color, but usu- 

 ally a decided burnt flavor is produced when milk is 

 so treated. The milk sugar undergoes a change and 

 whenever the quality of the milk sugar is affected, 

 the quality of the lactic acid produced is likewise 

 affected. 



This defect can be prevented by not heating the 

 starter milk to such high temperature as to affect 

 the character of the milk sugar. Heat the milk to 

 be used for a starter, once to a temperature of 180° 

 F. to 190° F. and hold at this temperature for forty 

 minutes. The finer qualities of milk for the pro- 

 duction of a fine, clean, acid starter are partially if 

 not wholly destroyed by overheating. 



188. Acid flavor. This flavor is due to too high 

 ripening of the cream, and to holding the ripened 

 cream at too high a temperature before churning. 

 It is also produced by holding ripened cream too 

 long before churning. When cream is held over from 

 one day to another there is danger of its developing 

 a sour, acid flavor even though the acidity in the 

 cream is low. Using an over-ripe starter may have 

 the same effect on the cream as over-ripening it. 

 Such acid flavors may be prevented by handling the 

 cream in such a way as to prevent the development 

 of lactic acid above .65 per cent. "When cream has 

 developed the desired degree of acidity it should 

 not be held at ripening temperature because such 

 temperature favors the development of other acids 

 not favorable for the production of fine flavored 

 butter. When lactic acid in cream has developed to 

 about .50 or .55 per cent acidity, it should be cooled 



