206 PASTEURIZATION 



the hot cream to "oil off," causing the fat to become granular 

 during subsequent cooling and giving the butter a mealy body 

 similar to that of renovated butter. 



In order to avoid appreciable lowering of the temperature 

 of the cream, with the coil revolving during the holding process, 

 the covers should be down. It is customary to empty the coil 

 as soon as the temperature has risen to 145 degrees F. in order 

 to avoid overheating and mealiness. When conditions are prone 

 to produce mealiness, a rise of a very few degrees above 145 

 degrees F. may cause this defect. Under such conditions it may 

 even be advisable to turn the steam off when a temperature of 

 140 degrees F. has been reached, then pull the cover down and 

 hold for 32 minutes, leaving the hot water in the revolving 

 coil. Experience has shown that with the hot water in *the coil at 

 the usual temperature at this stage of the process, there is suffi- 

 cient heat present to raise the temperature of the cream to 145 

 degrees F. in one or two minutes, but not enough heat to cause 

 the temperature to rise above 145 degrees F. during the holding 

 process. 



Cooling the Cream in the Vat Pasteurizer. After the cream 

 has been held at 145 degrees F. for 20 to 30 minutes, it should 

 be cooled as promptly as facilities permit. In order to economize 

 cold, the cream is best cooled with water to about 70 degrees F. 

 and then with brine or ice water to the churning temperature. 

 If starter is used it may be added when the temperature has 

 reached about 70 degrees F. For butter that is not consumed 

 promptly it is recommended to not add the starter until about 

 five minutes before churning. If it is not intended to ripen the 

 cream, it should at once be cooled to the churning temperature 

 and held there for not less than two to three hours. During 

 the cooling process the cover of the vat should be down. When 

 emptying the vat it should be rinsed down to reclaim the butter- 

 fat contained in the cream that does not automatically run out. 

 This rinsing should be done with the minimum amount of water 

 that will do the work, or preferably with skim milk. The ex- 

 cessive dilution of the cream with water is very objectionable 

 because it diminishes the power of the milk solids to protect the 



