OSaee STORRS AGRICULTURAL EXPERIMENT STATION. 
of the species isolated from ripening cream, showed this peculiar- 
ity. The few acid-producing species isolated did not produce so 
good effects on the butter as the alkaline producing species. 
Further experiments with acid-producing species are needed, 
however. 
SUMMARY. 
The most important points taught by these experiments may be 
summarized as follows : 
I. Different species of bacteria grown in the cream while ripening 
have different effects upon the butter flavor. The differences tn the 
resulting butter aroma are not very prominént in most cases, but are 
decided enough to make the difference between a first-class grade of 
butter and a second class. 
2. Pasteurizing cream at 70° C. will so largely destroy the bacteria 
in it, that a pure culture of bacteria subsequently tnoculated will pro- 
duce tts proper effects, not materially affected by the few OF gee 
left in the cream after pasteurization. 
3. Most species of bacteria found in cream of a good creamery 
produce good butter. The number which tnjure the flavor of the 
butter ts small. 
4. LVo one species of those experimented with, when used alone 
Sor ripening cream, produces a typically flavored butter, though many 
of them produce butter which ts excellent in flavor and which was 
preferred to that of the normal ripening. 

