New YorK AGRICULTURAL EXPERIMENT STATION. 285 
amount. In one case, the granules were fine and produced but- 
ter without mottles, while in-another case the granules were 
overchurned into lumps and mottled butter resulted. 
The matter of white specks of curd in butter, as the result of 
Over-ripened cream, we have not touched at all in our work, 
since all the facts in connection with this trouble have been well 
known for some years. 
RELATION OF TEMPERATURE OF CHURNING TO MOTTLED BUTTER. 
The temperature of churning was usually kept! between 50° 
and 55° F. but variations were made in special experiments, rang- 
ing from 43° to 61° F. Churning at higher temperatures favors 
the production of mottles to some extent, since overchurning 
takes place more readily at! higher temperatures and the butter- 
granules aggregate into larger masses more easily. 
RELATION OF SIZE OF BUTTER-GRANULES TO MOTTLED BUTTER. 
We controlled the operation of churning so as to produce but- 
’ ter-granules and aggregations of these varying in size. In our 
work we have designated the size of the granules as follows: 
Rice-grain size, pea-size (about a quarter inch in diameter), pea- 
nut size (about half an inch in diameter), hickory-nut size 
(about three-fourths inch in diameter) and walnut size (an inch _ 
or more in diameter). 
In general, when the butter-granules were the size of rice 
grains at the close of churning, it was easy to make butter free 
from mottiles by washing the granules twice with water at a tem- 
perature below 50 F°., preferably at 40 F°. But in several trials 
when the churning was made at 55° to 60° F. and the granules 
(rice-fine) were washed with water at 60° F., the butter was 
badly mottled since the granules adhered and formed lumps at 
that temperature before the washing could be completed. In 
several cases, we obtained very slight mottles when the tempera- 
ture of the wash-water was 50° tio 52° F., the granules being rice- 
fine. «4 
When the granules of butter were about the size of peas, there 
was no difficulty in making unmottled butter, provided the tem- 
perature of the wash-water was kept down to 40° F. When the 
wash-water was at 52° F., we had traces of mottles. When the 
