282 REPORT OF THE CHEMIST OF THE 
from which the butter is made is thin and allowed to ripen 
without being stirred, or when it is over-ripened without being 
strained. The cream being churned under these conditions, 
lumps of coagulated cream are incorporated in the butter, and as 
the casein does not take the butter color the result is a product 
full of white specks. When the. trouble is caused in this way it 
can be obviated by washing the butter twice in a weak brine 
after the buttermilk is thoroughly drained off. After the last 
washing, instead of draining the brine from the butter, as is 
usually done, the butter should be dipped out of the brine with a 
hair or wire sieve; the specks of curd, being heavier than butter 
or water, will have sunk to the bottom of the churn. 
“ Most of the mottles found in butter, however, are caused by 
an unequal distribution of salt. When the wash-water is consid- 
erably colder than the butter-granules the exterior of the latter 
become harder than the interior; this prevents an equal absorp- 
tion of the salt when the butter is salted and worked, and! mottles 
result. Also, when thin cream is churned at a low temperature 
the butter usually comes in round, shot-like granules; on 
account of being round and quite firm it is with difficulty that 
the salt is equally distributed and, unless great care is exercised, 
the finished butter is mottled. Of course, if under the most favor- 
able conditions the butter is not worked enough to distribute the 
salt equally, mottles will be noticed in the finished product. _ 
“Mottles may be prevented, then, by avoiding high tempera- 
tures in ripening cream, by frequent stirring during ripening, by 
straining the ripened cream into the churn, by avoiding exposure 
of the butter to temperatures too low while in granular form 
(which causes a difference between the interior and exterior of 
the butter-granules) and by. working the butter sufficiently to 
cause an equal distribution of the salt.” 
It is very noticeable that in all the dairy literature which has 
come to our hand there is no suggestion that the proteids present 
in the cream have any connection with mottles in butter, except 
that single form which comes from curdled casein specks or 
particles; but this form is of so infrequent occurrence, compared 
with the other form, that many teachers do not apply the term 
mottles to the discoloration caused by curd particles. It is to 
the other form of mottles that we have given our attention, 
