COMMERCIAL STARTERS IN BUTTER MAKING. 65 



ditions and minor contaminations, a pure lactic fer- 

 ment culture has been found indispensable in the 

 controlling of undesirable fermentations in cream. 



H. W. Conn, in Practical Dairy Bacteriology, 

 says: "The use of starters has frequently been 

 found valuable in avoiding undesirable taints and 

 tastes in butter. These unpleasant flavors which 

 in even the best creameries occur occasionally, can 

 frequently be checked or remedied by the use of a_ 

 considerable quantity of a proper starter." He also 

 says: "The acid which they (lactic acid bacteria) 

 develop seems to be injurious to other species and 

 these rapidly disappear as the lactic organisms in- 

 crease in numbers. As a rule, therefore, milk which 

 sours at about 70° F. will be found to contain nearly 

 a pure culture of a common lactic acid type, the 

 other organisms, that were so abundant at the out- 

 set having disappeared." 



86. Raw or pasteurized cream. Starters should 

 be used in both raw and pasteurized cream, but it 

 is only in pasteurized cream that the full benefit of 

 a starter is realized, because in this cream lactic 

 acid can develop without the interferance of other 

 fermentations. In raw cream, as a rule, a great 

 variety of other fermentations thrive and therefore 

 the full benefit of the starter is not always realized. 

 Lactic acid develops faster in pasteurized than in 

 unpasteurized cream. The poorer the cream is in 

 quality the larger should be the quantity of starter 

 added to it. 



