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 which butter should be 

 stored is an open one. It is at its best, however, when freshly made, 

 and its tine 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, which 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 



