ICE-CREAM FACTORIES 



177 



receiving vat. From here it runs through a pasteurizer, 

 then over a cooler which brings it to a temperature of 

 34 to 38 F., thence to huge holding vats in a refriger- 

 ated room, where it is held until needed. 



In another cold room is found sweet, unsalted butter, 

 stored at a temperature of about 10 below zero Fahren- 

 heit. This is usually secured by contract from whole milk 



FIG. 44. Sweet cream receivers in Collins Bros.' factory. 



creameries, and is of very good quality being " June extras" 

 and " Fall extras." 



To prepare the materials for the freezer, butter and 

 milk are placed in proper proportions in a mixing vat, 

 heated to about 140 F., and agitated to form an emulsion, 

 then passed through the homogenizer. The emulsion issues 

 from this machine as a homogeneous cream, thoroughly 

 pasteurized and with the fat thoroughly and permanently 



