PRACTICAL PAPERS—BUTTER FACTORIES. 
249 
“ Setting and Cooling the Milk .—From time immemorial the practice of 
setting the milk in very shallow pans has prevailed, and the opinion was 
formerly believed established, that only through a shallow mass of milk 
could the cream rise to the surface. This practice had its origin in the ne¬ 
cessity for cooling the milk soon after it is drawn from the cow, to prevent 
its souring before the cream could rise, and not, as has been very erroneously 
inferred, from any difficulty about the rising of the cream. Hundreds or 
even thousands of experiments have been conducted with the view to per¬ 
manently settle this question, and we have yet to learn of the first one 
which has not resulted in sustaining the principle that with proper appara¬ 
tus for cooling, it is of no possible consequence how deep the milk is set for 
the purpose of raising the cream. 
“ The cooling of the milk is of the first importance. It contains within 
itself the elements of decay, and when left to itself fermentation and putre¬ 
faction speedily ensue. But by reducing the temperature to about 58° or 
60°, the process is retarded, not prevented, and time is afforded the cream 
to rise before the other parts of the milk become so changed in their struc¬ 
ture as to entangle and hold the oily portion of the cream. But precisely 
the same effect may be produced by the application of heat, and we not un- 
frequently hear it recommended. In this case, however, the very important 
circumstance, that the oils which flavor the butter become volatilized and 
escape, is quite overlooked. 
“ It is believed, then, to be practically settled, that the best results are at¬ 
tained by reducing the temperature of the milk as soon as practicable, after it 
is drawn, to about 58° F. The milk should be placed in the vessels where it 
is to remain before the cooling is commenced, that the rising of the cream 
may not be retarded by subsequent agitation. The only really practicable 
method of cooling the milk, without agitating it, is to place it in compara¬ 
tively narrow vessels, and surround them with cold water, as high or higher 
than the surface of the milk within. It is idle to attempt to cool milk or 
any other fluid by the application of any cooling substance to the bottom. 
If the vessel itself be of a material which is a good conductor, it is a little 
help, but the process is at best slow and unsatisfactory. . 
“ We make the rule that milk should be set in vessels placed in water, 
and the temperature reduced as soon as may be, to about 58° F., but that 
the temperature of the room should be about 65° or 70° F. 
“ The form of the vessels is not material, if only they be so narrow that 
the cooling is effected in season to prevent the souring of the milk before 
the cream has risen. 
“ The most economical arrangement of which we have any knowledge, 
consists of a long, narrow tank, with a jacket of tin for the cold water. The 
most approved form is 8 inches broad, 11 inches deep, and 6 feet long, 
which is made from a single large sheet of tin, without seam or solder, ex¬ 
cept where the end and jacket are attached. If more than one is required to 
hold the milk at each milking, they should be placed side by side in the 
