CHEDDAR CHEESE-MAKING 



203 



the whey is drawn down to the surface of the curd and 

 the acid has developed sufficiently, the curd should be 

 firmed up in the whey by stirring it vigorously by hand 

 before the remainder of the whey is removed. This is 

 commonly called "hand stirring." This difficulty results 

 either from the use of too much 

 starter or from holding the milk 

 until too much acid develop- 

 ment has taken place before 

 adding the rennet. Hand stir- 

 ring accomplishes what natural 

 forces would accomplish if 

 given sufficient time. If the 

 curd does not firm naturally 

 in the whey, there is a large 

 loss of fat and other solids, be- 

 cause the pieces of curd will 

 have to be broken up to allow 

 the water to escape from the 

 soft centers of these masses. 

 This loss can usually be re- 

 duced by firming the curd in 

 the whey or adding water 

 rather than by stirring without 

 either water or whey. If the 

 curd is not properly firmed, it 

 carries extra whey into the 

 cheese. With the increase in whey, the amount of milk- 

 sugar carried into the cheese increases. This extra milk- 

 sugar attacked by bacteria produces an excess of lactic acid, 

 which results in " sour " cheeses. This explains why the 

 curd is placed beyond the danger of over-development 

 of acid by removing so large a portion of the whey. 



FIG. 37. Whey strainer with 

 spout to fit into the gate in 

 the vat. 



