CREAM-RIPENING. 199 



may not, produce good results. It has been termed by some 

 "chance ripening." At certain seasons of the year conditions 

 are favorable for natural ripening, while at other seasons con- 

 ditions are very unfavorable. It was stated before that putre- 

 factive organisms, or those germs causing ordinary decay, are 

 undesirable species of bacteria to have present in the cream. 

 During the late spring and early summer months, when the 

 cows are first put on pasture, the conditions are favorable for 

 the preponderance of the desirable germs; during the winter, 

 when necessarily the cows and the milk are subject to stable 

 conditions to a greater extent, the conditions are favorable for 

 the ascendency of the undesirable germs. Eckles has found 

 that during the winter about three-fourths of the bacteria in 

 milk consists of these undesirable germs. If these are present 

 in the milk, a proportionate part will be transferred to the 

 cream. When such cream is allowed to ripen or ferment in a 

 natural way, the undesirable germs are likely to gain the ascen- 

 dency. As the conditions which govern the degree of con- 

 tamination of the milk and cream vary during the different 

 days of the different months and different seasons of the year, 

 this natural ripening is not to be depended on for obtaining 

 a good uniform quality of butter, Q\ei\ though at times good 

 results may be obtained from natural ripening. A maker who 

 wishes to make a high, uniform grade of butter should not 

 depend upon natural cream-ripening. 



Artificial Ripening. — By artificial ripening we mean (1) 

 ripening of ra\^' cream to which sufficient starter has been 

 added to control the kind of fermentation; (2) ripening of cream 

 in which the germs have been destroyed by pasteurization, 

 and to which a starter has been added in order to introduce 

 the desirable ferments. 



(1) Either of these methods is preferable to natural cream- 

 ripening. The first method has been the most common in the 

 past, but the latter method promises to give results which 

 will warrant every butter-maker in adopting it as a permanent 

 method in butter-making. If cream has been handled under 



