38 



Milk fresh and warm from the cow is in the best possible condition 

 for a perfect separation. The difference in specific gravity between the 

 fat and other portions of the milk is then greatest, and it is also more 

 fluid, as there is no development of lactic acid, nor chemical changes due 

 to its exposure to the air. At t;he creamery, it is not met with in this 

 favorable condition ; consequently it is necessary to produce artificially as 

 many of the favorable conditions as possible to get the best results. When 

 milk is received at a temperature below 85 degrees, it should be heated to 

 from 90 to 100 degrees. 



A tempering vat should be elevated at a suitable heignt, to allow the 

 milk to flow into the separator ; and it should contain enough milk to em- 



UJ— C 



Skim-milk pasteurizer using 

 exhaust steam. 



A Milk inlet l}i" pipe. B. Exhaust steam inlet 2" pipe. C. Overflow^". D. Small valve on 



exhaust steam pipe to prevent suction of skim-milk back into steam pipe. E. ^ alye to drain heater. 



F. Plug which may be removed in order to see if heater is filling with mateiial from skim-milk. 



G. Heater 6" diameter. 18" long with caps screwed on each end. 



ploy the separator for at least four minutes. If large bodies of milk are 

 heated to the desired temperature in a vat before separating, acid develops 

 too rapidly and clogging of the separator bowl is likely to follow. Should 

 any accident happen whereby the separator is stopped, the milk would 

 likely develop acid enough to thicken, when it could not be separated. 

 While it is doubtless true that better butter can be made by pas- 

 teurizing the whole milk before separating, still the improvement is not 



