82 BULLETIN 98, U. S. DEPARTMENT OF AGRICULTURE. 
The cooling of wash water is done in tanks which should be located 
at an elevation sufficiently great to command the butter worker and 
churn. The cooling is done either by direct expansion or brine 
coils submerged in the tank. The capacity of the tank necessary will 
vary with the size of creamery, but tanks holding from 100 to 500 
gallons are of sufficient capacity for the majority of creameries. 
In the medium and smaller sized creameries a cold storage is pro- 
vided of sufficient capacity to hold at least a week's output of butter, 
as it is not always convenient to make shipment as soon as made. 
The question of the proper temperature at winch butter should be 
stored is an open one. It is at its best, however, when freshly made, 
and its fine quality will last only a few days if kept at the ordinary 
summer temperatures. Experiments show that the changes which 
take place in butter and cause rancidity and other disagreeable flavors 
diminish as its temperature is reduced. Consequently its quality is 
determined by the temperature at which it is held rather than the 
time. The quality and flavor of butter will eventually deteriorate 
under any storage temperature that has so far been tried. There- 
fore, the effect of storing at different temperatures is only a matter 
of degree and not of absolute stoppage of all changes. 
It is believed that in the individual creamery where not over a 
week's output is in storage at one time, that a temperature of 32° 
F. is satisfactory where mechanical refrigeration is available. Where 
refrigeration is accomplished by using ice, it is impracticable to get so 
low a temperature, 50° to 45° F. being about the temperature main- 
tained in the best ice refrigerators. 
LOCAL CREAMERIES. 
Local creameries are either cooperative or privately owned, and 
receive milk or cream, or both, from the immediate vicinity or from 
their auxiliary creameries located near by. Their equipment usually 
consists of pasteurizers, coolers, churns, etc., with the necessary 
motive power apparatus, and often separators for handling the whole 
milk, winch may be delivered direct to_the creamery instead of to the 
auxiliary creamery. Often the local creamery is not supplied by 
auxiliary creameries but depends on the farmers of the immediate 
vicinity who deliver the whole milk directly to the creamery, in 
which case the local creamery does all the separating. Probably 
the majority of local creameries are supplied with cream separated 
on the farm and delivered by the patrons to the creamery, or col- 
lected by cream haulers. 
In a local creamery making, say, 2,000 pounds of butter daily 
the method of operation is as follows : 
In the morning the cream which has been allowed to stand and 
ripen overnight in the ripening vats is emptied into the churns 
and the churns started. About three-quarters of an hour is required 
