242 MARKLT DAIRYING 
3. By the aided development of the lactic fermenta- 
tion called starter ripening. 
I. NATURAL RIPENING. 
By this is meant the natural souring of the cream. In 
this method no attempt is made to repress the abnormal 
fermentations or to assist in the development of the lactic. 
From the chapter on Milk Fermentations we have learned 
that milk normally contains a number of different kinds 
of germs, frequently as many as a dozen or more. Natur- 
ally, therefore, where this method of ripening is practiced, 
a number of fermentations must go on simultaneously and 
the flavor of the butter is impaired to the extent to which 
the abnormal fermentations have developed. If the cream 
is clean and uncontaminated the lactic fermentation 
greatly predominates and the resulting flavor is good. If, 
on the other hand, the cream happens to contain many bad 
germs the probability is that the abnormal ferments will 
predominate and the flavor of the butter will be badly 
“Otte? 
Where cream is therefore allowed to take its own course 
in ripening the quality of the butter is a great uncertainty. 
This method, though still practiced by many butter mak- 
ers, is to be condemned as obsolete and unsatisfactory. 
2. PASTEURIZED CREAM RIPENING, 
Theoretically and practically the ideal way of making 
butter is to pasteurize the cream, a process which consists 
in heating cream momentarily to a temperature of 160° 
to 185° F. and then quickly cooling to 60° F. In this 
manner most of the bacteria in the cream are destroyed. 
After this treatment the cream is heavily inoculated with 
the lactic acid bacteria, and the lactic fermentation is given 
