48 STORRS AGRICULTURAL EXPERIMENT STATION. 
‘as normal cream, and a longer time would therefore be required 
for bacteria growth. 2. Our cream continued a nearly pure cul- 
ture, and the changes in the cream would be less rapid than 
when several species were working together. As is well known, 
a bacteria culture increases most rapidly in the first period of its 
growth. Later the growth is greatly checked. For this reason, 
cream would more slowly be changed by a single growing species 
than by several growing together, even though at first the actual 
number of individuals was the same. In a few experiments with 
combined cultures it was found that the ripening was more rapid 
than with an equal quantity of a pure culture. ‘These facts ex- 
plain the result which may appear so strange to a butter maker, 
that cream has been ripened forty-eight hours at 20°C. (68° F.) 
and then found to be under-ripened and too mild. 
After the ripening had continued the proper length of time 
for the experiment, the cream was tested as to its acid or alkaline 
reaction. Note was made as to whether bubbles of gas had been 
produced during the ripening, as to whether the cream had 
noticeably thickened or not, and very careful note was taken of 
the odor and the taste of the ripened cream. ‘The cream was 
then cooled to a temperature of 14% degrees C. (58°F.) and was 
then churned. For churning we used an ordinary milk-shaking 
machine, such as is used by druggists for shaking liquids. The 
fruit can, about half full of cream, was placed in the shaker and 
the churning occupied only a very short time, varying from one 
to ten or twelve minutes, according to conditions, and according 
to the different species of bacteria that had been used in ripen- 
ing. After churning, the butter was washed once or twice in 
water at a temperature of 15°C. (59° F.), and was then worked 
between butter ladles so as to remove the excess of buttermilk 
and to imitate as closely as possible the ordinary method of 
butter working. In some of the experiments salt was added to 
the butter in the proportion of one to sixteen. In other experi- 
ments the butter was worked without salting. It was found that 
is was preferable not to salt the butter before testing, inasmuch | 
as the salting more or less disguised the flavor produced by the > 
ripening, and in these experiments, in some of which the aroma 
was quite delicate, it was desirable to have the flavor given to 
the butter as prominent as possible. It was found that those to 
whom the butter was submitted for tasting could very much more 
readily determine the flavor of the butter without the previous 


