284 REPoRT OF THE CHEMIST OF THE 
of time before working, from a few minutes to one or two hours, 
according to convenience. 
RELATION OF RICHNESS OF CREAM TO MOTTLED BUTTER. 
Cream was separated so as to contain 40 per ct. of fat, and 
from a portion of this we made cream containing 20 per ct. of fat 
by adding skim-milk The creams were handled under the same 
uniform conditions. The churning temperature was 50° to 52° 
F.; the granules were treated twice with wash-water at 45° F.; 
salt was added at the rate of one ounce to a pound of butter. 
When the butter-granules were about the size of grains of rice, 
there were no mottles in either case, but when the butter was 
over-churned and gathered in chunks, mottling took place. In 
the case of the rich cream, when over-churned, the butter was 
pasty and the mottles occurred in large patches, the whole mass 
of butter being rather light-colored from the presence from an 
excess of buttermilk. The richness of cream does not appear 
to have any influence in causing mottles in*butter provided it is 
handled in a normal manner during the process of butter-making. 
More care needs to be exercised in churning rich cream to prevent 
over-churning than in case of cream poorer in fat. : 
RELATION OF RIPENESS OF CREAM TO MOTTLED BUTTER. 
We churned creams having acidity of .22 and .25 per ct. and 
also some of the same creams ripened to acidity of .4 and .65 
per ct. These were all churned at 55° F. and the granules 
washed twice with water at 40° F. The sweet cream, was 
churned so as to come in fine granules and in lumps as large 
as hickory nuts or larger. The ripened cream was similarly 
treated. The butters were salted in the usual way. In each 
case, mottles were obtained in the butter in the case of the over- 
churned cream and no mottles in the butter made from granules 
of the usual size. In numerous other experiments, we have 
varied the acidity of the ripened cream from .88 to .78 per ct. and 
obtained butter without mottles except as the result of some 
condition other than-that of the acidity of the cream used. 
In one case, we added a starter to some sweet cream and 
churned at once, churning at 52° F. and washing the but'ter- 
granules twice with water at 45° F. Salt was added in the usual 
