PASTEURIZATION 



207 



fat globules against mutilation during the churning process and 

 tends to give the butter a poor body, susceptible to the develop- 

 ment of serious butter defects. 



Temperature Control in Vat Pasteurization. Vat pasteuri- 

 zation offers greater facilities for temperature control, because 

 of the larger volume of cream simultaneously heated than is 

 the case with flash pasteurization. Nevertheless the process, if 

 it is to be dependable and successful, requires the constant -at- 

 tention of the operator. The installation and use of a tem- 

 perature recorder in this process, too, is a great help in order 

 to insure accurate work. 



Flash and Holding Pasteurization Combined. In some in- 

 stances the two systems of pasteurization are combined, the 

 cream being heated in the flash pasteurizer and held in the vat. 

 For this purpose anyone of the flash pasteurizers above referred 

 to may be used. The cream is run through the flash pasteurizer 

 at 150 degrees to 170 degrees F. From the flash machine it is 

 allowed to flow into the vat or retainer where it is held for from 

 10 to 30 minutes at the desired temperature and then cooled. 

 This method is more generally used in milk plants. Very few 

 creameries have adopted it. 



rig. 35. Progress internal tube pasteurizer, holder and cooler 

 Courtesy Davis- Watkins Dairymen's Mfg. Co. 



