CRKAM RIPENING 243 



bacterial flora of winter cream, tend to delay the souring, while 

 in summer they are favorable to rapid souring. 



Cream rich in fat will take care of a relatively large amount 

 of starter to good advantage, while the addition of large quan- 

 tities of starter to thin cream would be a distinct disadvantage, 

 the resulting dilution reducing the readiness and exhaustive- 

 ness of the churning and decreasing the churn yield. 



Finally, the amount of starter used is controlled in a great 

 many creameries by the availability and expense of milk and 

 skim milk and other materials for starter making. Especially 

 in the smaller gathered cream creameries the scarcity of a goo4 

 quality of skim milk and the high price of other starter media, 

 such as condensed milk and milk powder are a serious obstacle 

 in the way of the use of a large amount of starter. 



Time Required for Ripening. The time required for the 

 ripening of cream depends on a variety of factors, some of 

 which are ever changing. Generally speaking, quick ripening, 

 if not done at too high temperatures, insures a purer lactic acid 

 fermentation, greater freedom from the development of injurious 

 fermentations and undesirable flavors than slow ripening. Unusu- 

 ally quick ripening is the result of the use of a large percent of 

 active starter while slow ripening, other conditions being the 

 same, is caused by the use of a small amount of starter, or 

 starter that has lost some of its vitality and has become slug- 

 gish. The longer the ripening period, the greater is the danger 

 of the development of undesirable fermentations and flavors 

 at the expense of the pure lactic acid fermentations. Slow 

 ripening further jeopardizes the quality and especially the keep- 

 ing quality of butter due to excessive exposure of the fat and 

 curd to the acid, inviting partial decomposition of one or both 

 of these ingredients. 



Sweet cream will generally require a longer ripening period 

 than sour cream, in order to secure the desired degree of acidity 

 and it will stand the longer ripening without danger of injury 

 to the keeping quality of the butter better than sour cream. 

 In the case of cream that is sweet and of good quality and 

 relatively rich in butter fat, such as cream testing 35 per cent 

 fat or over, the addition of a heavy starter, cooling immediately 



