8 BULLETIN 1013, U. S. DEPARTMENT OF AGRICULTURE. 



added to the samples, although not definitely stated in the diagrams, 

 may be ascertained by subtracting from 15 per cent the percentage 

 of moisture contained in the wheat before tempering. 



INFLUENCE OF RELATIVE HUMIDITY ON MOISTURE CONTENT 



OF FLOUR. 



Concerning the influence of atmospheric humidity on the moisture 

 content of flour, Bailey 3 in his investigations on that subject con- 

 cludes that "flour responds readily to changes in the humidity of 



RELATIVE HUMIDITY- PER CENT 



34 

 and 

 lower 

 15.0 



Number of Tests 



l^ IG . 4. Showing that as the -relative humidity of the atmosphere within the mill in- 

 creases there is a corresponding increase in the. moisture differential of the flour and 

 of the wheat from which it is milled. 



surrounding air, the rate at which equilibrium in moisture is ap- 

 proached depending apparently upon conditions of exposure." 



An indication of the effect of relative humidity on the moisture 

 content of the flour produced in connection with the experimental 

 milling tests herein described is showji in figure 4. The results in- 

 dicate a decided tendency for the moisture content of the flour 

 product to be highest for the higher relative humidities. At 

 relative humidities ranging from 35 to 39 per cent, the average 



" Bailey C H The Hygroscopic Moisture of Flour Exposed to Atmospheres of Differ- 

 ent Relative Humidity, Journal of Industrial and Engineering Chemistry, vol. 12, No. 11, 

 p. 1102. Nov., 1920. 



