THE RIPENING OF CREAM. 2 
THE RIPENING OF CREAM. 
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THE OBJECT OF THE EXPERIMENTS. 
Experiments upon the ripening of cream that have been 
carried out in this laboratory and elsewhere in past years have 
been confined largely to efforts to separate from milk or cream 
different species of bacteria, and then by inoculating pasteur- 
ized cream with pure species of the isolated organisms, to 
determine the influence that each species might have upon the 
cream if acting alone. ‘These experiments have resulted in 
showing that different milk bacteria vary decidedly in their 
influence upon ‘the character of butter. Hitherto, however, 
no description has been given of careful experiments showing 
the exact bacteriological condition of normal cream before it is 
ripened, or the change in bacteriological content that occurs 
during the ripening. 
The object of the experiments here described has been to 
. determine so far as possible the types of bacteria which pro- 
duce the ripening of cream under the zorma/ conditions of a | 
Connecticut dairy. Manifestly there is an advantage in de- | 
termining the actual changes that occur in cream in normal 
ripening; and for practical purposes the results of these inves- 
tigations may possibly be of more value than those of expert- 
ments with pure cultures. They may be of importance in at 
least two ways: First, they may settle the question over which 
there has been some dispute, as to whether the acid organisms 
alone are concerned in cream ripening, or whether the non- 
acid species may assist in producing good butter; and second, 
they may be of aid in determining how to handle starters, by 
pointing out a more satisfactory method of obtaining artificial 
cultures for cream ripening, which shall produce results more 
in harmony with those desired than are obtained by the use of 
any culture now employed by dairymen. 
Probably the reason that such experiments have not been 
undertaken hitherto lies in the extreme difficulty in carrying 
