SECRETARY'S REPORT. 97 



and teacher of this method, says, " When the temperature of the 

 cold milk is 65° or upwards, no sour whey ought to be used, the 

 acid then being present in a sufficient degree without it. When 

 the temperature is higher, every operation of the process needs to 

 be accelerated, until the curd is taken out and salted ; for when 

 too much acid is present, it affects the curd so as to render the 

 cheese hard and give it a sour taste." 



The temperature of the milk when the rennet is added is next to 

 be attended to, and is a point of great importance. It has been 

 found by experiment that milk coagulates soonest when at a tem- 

 perature of about 115°,* but when curdled at so high a tempera- 

 ture the product is much injured. The proper temperature, as de- 

 termined by experience, is usually from 85° to 88°, and the whole 

 range admissible, under the varying conditions which sometimes 

 occur, is not more than ten degrees, — namely, from 80° to 90°. If 

 set below 80° the curd is long in coming, (unless an excess of ren- 

 net is added, which is highly objectionable,) is too tender, and the 

 separation of the whey is attended with greater labor, and, unless 

 extreme care is used, with loss also. If it be set at a temperature 

 above 90°, the curd assumes a toughness which is objectionable, 

 and the cheese made from it is hard and of inferior quality. 



How shall the proper temperature be determined ? My answer 

 is, by the use of a thermometer,! and in no other way. The an- 

 swer given by the practice of a majority of dairymen and dairy- 

 women is, by the feelings, by judgment, by the verdict of a prac- 

 ticed hand ; and doubtless they honestly believe these to be suf- 

 ficient, and may ridicule the use of a scientific instrument to de- 

 termine so simple a matter. But the truth is that feelings, though 

 very useful in their place, are not to be depended upon to determine 

 temperature. Our bodies are unconsciously affected by too many 

 disturbing causes, to afford a reliable index to slight differences. 

 Tell a man suffering from fever and ague that he is no warmer now, 

 when seeming to be on fire, than he was a little while ago, when 



* I could detect but little difference in the time required from 110 to 120 degrees, 

 but above or below this point the time required was longer ; and a degree of heat 

 equal to 160 degrees or upwards seemed entirely to destroy the coagulating power of 

 the rennet. 



t Many cheap thermometers seem like Pindar's razors, made to sell ; but of late 

 years the demand for and the manufacture of these instruments have greatly in- 

 creased, and the price correspondingly diminished. A reliable one can now be had 

 for seventy-five cents to a dollar at retail, or from five to eight dollars per dozen. 



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