24 SCIENCE AND PRACTICE OF CHEESE-MAKING 



of milk, some portions being too hard and others 

 too soft. Imperfect coagulation results (i) in ex- 

 cessive loss of fat and of casein from the soft curd and 

 (2) in imperfect texture and body in cheese, due to 

 the hard pieces of curd. 



The causes of imperfect coagulation may be: 



(1) For incomplete or delayed coagulation: 



(a) Jarring of milk after coagulation starts. 



(b) Weak rennet-extract or too small an amount. 



(c) Low temperature, due to inaccurate thermometer 

 (p. 309). 



(d) The presence of formalin (p. 308). 



(e) Abnormal milk, containing small percentage of 

 casein or small percentage of calcium salts (p. 164). 



f) Pasteurized milk (p. 310). 



;) Presence of abnormal bacterial ferments. 



i) Heavily watered milk (p. 307). 



i) Use of badly rusted milk-cans (p. 309). 



(2) For uneven coagulation: 



(a) Uneven temperature of milk in vat, due to lack of 

 thorough agitation. 



(b) Adding rennet to milk too soon after heating, while 

 the sides and bottom of the vat are still hot. The curd sticks 

 to the sides of the vat and makes cutting difficult. 



(c) Agitation of milk after coagulation begins. 



(d) Uneven distribution of rennet -extract. 



