Factory Cheese-making. 



35 



cloth, so that there may be no lumps of coagulated milk put 

 into the vat. The milk should be so ripened that it will take 

 from three and a-half to four hours from the time the rennet 

 is added until the curd is ready to press. The degree of 

 ripeness necessary to accomplish this result is determined by 

 experiment on the part of the maker. When cheese is to be 

 coloured, the colouring extract is put into the milk in the vat 

 and well mixed at least ten minutes before adding the 

 rennet. 



When, in the judgment of the operator, the milk is ready, 

 sufficient rennet is added to coagulate the mass in about 

 thirty minutes. The curd being set, it is ready to cut when 

 it will break clean over the finger. The curd is cut length- 

 wise and crosswise with horizontal and perpendi- 

 cular knives. These leave the curd in cubes with a side 

 of about one-third of an inch. The degree of fine- 

 ness into Avhich the curd is to be cut depends on the 

 ripeness ot the milk, and is a matter which is determined 

 by the manner in which the moisture is expelled from the 

 curd before the whey is drawn. About an hour and a half 

 usually elapses from the time heat is applied to the vat 

 until the curd is cut. After cutting, the curd is gently 

 agitated to prevent it from settling at the bottom of the vat 

 and matting together. The stirring allows the curd to 

 shrink and expel the whey or a portion of it. The kernel or 

 small cube or lump of curd forms a thin skin or film over its 

 surface, which prevents the fat globules and other cheese 

 constituents from working out into the whey. The stirring 

 of the curd after it is cut is sometimes done by a hand tooL 

 called the curd-rake, but a better factory-appliance for this 

 purpose is an automatic curd agitator, which is attached 

 to the vat and worked by steam. After stirring the curd for 

 about ten minutes heat is applied again to the vat through 

 its water jacket, slowly at first, as if heated too quickly the 

 pieces of curd would cook on the outside and thus retain 

 the whey. After a temperature of about 92 0 F. is attained 

 the curd is heated more rapidly until the required temperature 

 of 97 0 to ioo° F. is reached. This process, which is often called 

 "cooking the curd," usually occupies about one hour. 



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