8 
BULLETIN 1013, U. S. DEPARTMENT OE 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 
s 
I 
34 35 
and to 
lower 39 
15.0 
14.0 
13.0 
12.0 
1 1.0 
10.0 
Number of Tests 
Fig. 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 shown 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 
3 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. 
