12 BULLETIN 1013, IT. S. DEPARTMENT OF AGRICULTURE. 



tempered to the same final moisture content of 15 per cent, are as 

 follows : 



With each increase of relative humidity or, in other words, with 

 each increase in the extent to which the air within the mill became 

 saturated with moisture, there was an appreciable decrease in the in- 

 visible loss occurring during milling and a proportionate increase 

 in the total yield of mill products. 



The higher total yields of mill products were associated with the 

 higher relative humidities and with the wheats of lower moisture 

 content. These higher yields in the former case were undoubtedly 

 due to decreased evaporation during milling of the moisture con- 

 tained in the wheat and probably to the absorption of some moisture 

 from the atmosphere by some of the mill stocks; and, in the latter 

 case of lower moisture content wheats, to the greater amounts of 

 water which it was necessary to add in tempering these wheats in 

 order to bring their moisture contents to the required percentage. 

 Each 10 per cent increase in relative humidity above 35 per cent 

 increased the total weight of the products obtained about one-half 

 of 1 per cent, and each decrease of 1 per cent in the moisture content 

 of the wheat before tempering caused about six-tenths of 1 per cent 

 increase in yield. Compared with the weight of the wheat before 

 tempering, the samples containing from 9 to 9.9 per cent moisture 

 showed a net gain in weight of total mill products for all relative 

 humidities given, while the samples containing from 12 to 12.9 per 

 cent moisture before tempering showed a net loss in weight of total 

 mill products except for relative humidities higher than 60 to 69 

 per cent. 



No very pronounced relation between the moisture content of the 

 flour and that of the wheat before tempering was shown, or in 

 other words, no relation was shown of moisture content of flour to 

 the quantity of temper water added to the wheat. On the other hand, 

 a decided tendency was shown for the moisture content of the flour 

 to increase as the relative humidity increased, a difference of 10 per 

 cent in relative humidity, making an average difference of approxi- 

 mately one-half of 1 per cent in the moisture content of the flour. 



No definite relation between air temperature and total yield of 

 mill products was established. 



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