MOISTURE IlSr WHEAT AHSTD MILL PEODUCTS. 11 



at the time the samples were obtained. The duration of the test 

 run was 12 hours for mills Nos. 1 and 2, and 2 hours for mill No. 3. 

 The wide range among the mills shown here in the yields of the differ- 

 ent flours has little general significance, because each of these mills, 

 within certain limits, varied the quality of its flour product to meet 

 the requirements of its trade. 



It is interesting to note that the moisture content of the patent 

 flour of each mill was lower than that of the untempered wheat. 

 This is even true in the case of mill No. 1, where the increase in 

 moisture content during tempering was as great as 3.60 per cent. 

 This fact further substantiates the conclusion already expressed that 

 very little of the water added to the wheat during tempering pene- 

 trated deeper than the pericarp, or branny portion of the kernel. 



The moisture content of the clear flour of miUs Nos. 1 and 2 is 

 shown to be slightly higher than that of the patent flour. For mill No . 3 

 the clear and low grade flours were combined ; consequently, the moist- 

 ure content given is not representative of each separately, but is, no 

 doubt, too low for the former and too high for the latter. 



Another interesting observation is that the low grade flour, red 

 dog, and white shorts had a lower moisture content than the brown 

 shorts or bran. This further indicates that little of the moisture 

 added during tempering penetrated beyond the pericarp. 



GAINS AND LOSSES IN WEIGHT EFFECTED BY CHANGE IN MOISTURE CONTENT INCIDENT 

 TO TEMPERING AND MILLING. 



In part 5 of Table II are shown the percentages of weight gained or 

 lost by the addition or evaporation of moisture incident to the 

 tempering and milling processes. The calculation of the relative 

 amounts gained or lost is based on differences in moisture content 

 of the untempered wheat, the tempered wheat, and the mill products. 

 The average moisture content given here of the mill products is cal- 

 culated from the moisture content and milling yield of the products 

 referred to in part 4. 



The change in weight resulting from the change in moisture content 

 of the wheat during cleaning and tempering shows for mill No. 1 a 

 gain of 4.29 per cent, for mill No. 2 a loss of 0.12 per cent, and for 

 mill No. 3 a gain of 0.74 per cent. 



The loss in weight of the cleaned and tempered wheat through 

 evaporation of moisture during the process of milling, is shown to 

 have been 3.84 per cent for mill No. 1, 0.91 per cent for mill No. 2, 

 and 1.63 per cent for mill No. 3. These losses show a correspondence 

 to the gams resulting from tempering in that the mill showing the 

 greatest gain during tempering had the greatest loss during milling, 

 and the mill showing the least gain during tempering had the least 

 loss during milling. 



