120 THE BOOK OF BUTTER 



cream and set at 58° to 60° F., for by this time there is 

 a very large army of bacteria at work. On Wednes- 

 day morning churn the forty pounds of cream and start 

 the ripening process anew with Wednesday's cream. It 

 is important to watch carefully and maintain the desired 

 temperatures, to stir the cream thoroughly after each 

 addition of fresh cream, and not to over-ripen it. 



RIPENING TEMPERATURES 



88. Proper temperature. — Ripening temperatures for 

 cream are usually between 60° and 75° F. The degree 

 of temperature that should be used depends on the time 

 that can be allowed for the ripening process, on the quan- 

 tity of the starter that has been added, and on the amount 

 of lactic acid that must be developed. When these fac- 

 tors are named, it is understood that the temperatures 

 given are actually maintained. Often it is difficult to 

 hold a certain degree of temperature because of varying 

 conditions in the creameries ; such as, the nature of the 

 apparatus and the quantity of cream that is handled, 

 and the method of heating the building. If the quan- 

 tity of cream is large, if the cream-vat is well insulated, 

 and if it is provided with a tight-fitting top, very little 

 difficulty is experienced in holding a fairly uniform 

 temperature. On the other hand, if an open vat with 

 poor insulation is Used, there can be practically no control 

 of temperatures. 



89. Temperature and inoculation. — When the inocula- 

 tion of the cream has been large, a fairly low temperature 

 may be employed, and, vice versa, when the transfer has 

 been small a higher temperature should be used. If 

 extremely quick ripening is desired, it may be accomplished 

 by a large inoculation of starter and a high ripening tern- 



