616 ANNUAL, REPORT OF THE Off. Doc. 



curd. ■ How can we ascertain this? The behavior of the eiiid will 

 give us this ueeded information. In the first place, the curd particles 

 should be contracted to less than one-half their original size, and, 

 in the second place, they should be so firm and rubber-like that 

 when a mass of curd is pressed together between the hands and 

 then suddenly freed from pressure, they should fall apart at once, 

 and show no tendency to stick together. During the heating, the 

 particles of curd should be examioed occasionally to ascertain 

 whether they are changing on the inside as well as outside. The third 

 sign given by the curd is probably the most useful to go by in de- 

 ciding when the curd has been heated long enough and when the 

 whey should be removed, and that is what is known as the ''hot- 

 iron test." When a small mass of curd, which has been squeezed 

 in the ha«d to remove whey, is pressed against a bar of iron, heated 

 a little short of redness, and then carefully drawn away, fine, silky 

 threads are formed, adhering to the iron. These strings are caused 

 by the compound of lactic acid and paracasein and the more of this 

 compound there is, the more the curd will striog in length. So the 

 hot-iron test is really a measure of the amount of acid that has 

 been formed. Now, when the curd shows, by the hot-iroo test, 

 strings one-eighth of an inch long, the whey is drawn from the curd. 

 The removal of the whey is sometimes called "dipping," or ''draw- 

 ing," the whe3\ When the development of lactic acid has been 

 rapid or promises to be, it may be well, when the curd has reached 

 98 degrees F., to let it settle and draw off part of the whey; leaving 

 enough to cover the curd two or three inches deep. Then the rest 

 of the curd can be removed when the curd strings one-eighth of 

 an inch. Too much acid at this point must be guarded against, and 

 the whey must be promptly removed when the right point is reached. 



56. Cheddaring the Curd. 



This operation is the distinguishing feature of the cheddar method. 

 It consists essentially in allowing the curd to mat or pack together 

 in solid chunks after the removal of the whey. The matting pro- 

 cess may take place in the vat directly on the bottom or on curd- 

 racks placed in the bottom of the vat or it may be removed to a 

 special apparatus called a curd-sink. 



(1.) Matting Curd on Vat-Bottom. — When the bottom of the vat 

 is used, the curd, after the removal of whey, is piled up along the 

 two sides of the vat with an open channel between the two piles 

 of curd to facilitate the running off of the whey that drains from the 

 curd. When the particles of curd have matted together, forming 

 one solid mass, it is cut into chunks or blocks ateout 8 by 8 by 12 

 ioches; these blocks are then turned over so that the part at first 



