PASTEURIZATION 211 



desirable ta continue its operation. In the case of vat pasteuri- 

 zation this objection is largely eliminated. The usually limited 

 knowledge of the preparation of cream for pasteurization on the 

 part of the average operator in the small, local creamery renders 

 the successful operation of the continuous machine often dif- 

 ficult. The high temperatures employed in flash pasteurization 

 intensify the usual difficulties, such as abnormal curdling, etc., 

 which are encountered with cream of varying quality, acidity and 

 richness. The vat pasteurizer with its lower temperature facili- 

 tates the handling of cream in this respect. The simplicity of the 

 vat pasteurizer and the ease of operation are in its favor under 

 the conditions of the small creamery. 



Capacity. For heavy duty and maximum capacity the flash 

 or continuous process excels. In the flash process the heating 

 and cooling is practically instantaneous and requires little time 

 additional to that needed for filling the vat with the cream, 

 while in the vat process, after the vat is filled, the heating, hold- 

 ing and cooling require from one and one-half to two hours for 

 each vat full of cream. When a small amount of cream is 

 handled this delay may not be so great a factor. But in a 

 creamery manufacturing large quantities of butter daily, the 

 speed of operation is an essential factor. In fact, the limited 

 capacity of the plant may demand this extra speed in order to 

 increase the working capacity of the plant and make possible 

 the handling of all the cream received during the flush of the 

 season. 



Durability of Equipment. Originally the vat with agitating 

 coil was intended only for control of the temperature of the 

 cream during ripening and cooling. It was not intended for 

 pasteurization of the cream. The wide range of temperature 

 between the heating and cooling medium and the operation of 

 the heating and cooling itself places an extremely heavy tax 

 on the vat pasteurizer, and the exposure of the coil and liner 

 to high acid in the cream and to the neutralizer, augment the 

 wear and corrosion of the machine. 



Especially where used for heavy duty, as is the case in 

 many creameries during the flush of the season, when the vats 

 are refilled with batch after batch of cream, practically day and 



