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 hefore 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, even though at times good 
results may he 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 raw 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 
