286 REPORT, OF THE CHEMIST OF THE 
butter granules were allowed to get as large as hickory nuts, 
mottled butter resulted in nearly every case, even when all other 
conditions were favorable to the production of unmottled butter. 
If, however, the buttermilk was once well removed, we found 
that aggregation of granules did not produce mottles. In several 
experiments we churned well-washed butter granules in water at 
a temperature of 60° F. and allowed them to aggregate into 
lumps the size of walnuts and no mottles were found in the 
finished butter as a result of this treatment. 
It would, therefore, appear that any condition favoring the 
production of large aggregations of granules of butter before 
removal of buttermilk, such as overchurning, churning at higher 
temperatures, using wash-water at 60° or above, will favor mot 
tling. In other words, failure to remove buttermilk from the 
butter-granules favors the production of mottles. 
In this connection, it may be well to consider the manner in 
which buttermilk is retained in. butter. We may for practical 
purposes regard buttermilk in butter as being present in two 
different relations. In the first relation the buttermilk is held 
enclosed in every individual granule of butter, and in the second 
relation it adheres mechanically to the outer surfaces of each 
granule. The buttermilk held within the minute granules can 
not' readily be removed, while that adhering to the outer surfaces 
can be practically all removed by proper treatment of the 
granules with cold water. It is the buttermilk adhering to the 
outer surface of the small granules that we must consider in rela- 
tion to mottles. 
RELATION OF TEMPERATURE OF WASH-WATER TO MOTTLED BUTTER. 
Best results were obtained by washing the butter granules with 
water at about 40° F. or even lower. Water at a temperature of 
60° EF. or above tends to make the granules adhere to one another 
and form larger masses, thus tending to prevent a sufficiently 
complete removal of buttermilk. It is important that the wash 
water be cold enough to keep the granules separate during the 
treatment with water. 
RELATION OF WORKING BUTTER TO MOTTLED BUTTER. 
When butter came in rice-fine granules and these were properly 
washed with cold water, working had no influence in producing 
