HANDLING WHEAT FROM FIELD TO MILL, 7 



for circulation of air, and any heat generated by biological action is 

 retained in the grain until finally the temperature becomes so high as 

 to cause other chemical changes within the kernels; the result is what 

 is commonly known to the grain trade as heat-damaged or "bin- 

 burnt" wheat. This injm-y may extend simply into the branny 

 coats and produce slightly heat-damaged or " bran-burnt " wheat, or 

 it may extend throughout the endosperm and produce badly heat- 

 damao-ed or "bin-burnt*' kernels. AVheat in this last condition is 

 practically unfit for flour-making purposes. 



There is little evidence as to whether or not this change or sweat 

 Avhich takes place in the bin is identical with that which takes place 

 in the stack. It at least appears to have much the same effect on the 

 milling and baking qualities, provided the wheat is not allowed to 

 heat enough to become injured or "bin-burnt." 



EFFECT OF SWEATING IN STACK ON APPEARANCE AND TEST 



WEIGHT. 



In order to make a preliminary test regarding the validity of the 

 practically unanimous opinion among farmers and millers that wheat 

 which had been bleached in the shock was improved in color and 

 test weight per bushel upon being stacked and allowed to go through 

 the sweat in the stack, and also to discover what effect this sweating 

 process in the stack would have upon the market grade and the 

 milling and baking value of the wheat, arrangements were made 

 during the harvest of 1909 to secure from a 12-acre field of Fife wheat 

 near Fargo, X. Dak., a load of bundles taken from the shock after 

 they had been exposed to at least two heavy rains. This load was 

 thrashed and the wheat stored in a small elevator bin. The remain- 

 der of the field was stacked and after standing in the stack six weeks 

 was thrashed. Fifty bushels of the stacked wheat, taken from the 

 same portion of the field as the before-mentioned load of shocked 

 bundles, was placed in another small bin in the same elevator for 

 comparison with the shock-thrashed wheat. 



The shock-thrashed sample as it came direct from the thrashing 

 machine contained 14.8 per cent of moisture, and the test weight 

 per bushel was 55.5 pounds. The grain felt damp and tough and 

 would scarcely have been considered in safe condition for shipment 

 to market. 



MILLING TESTS OF SHOCK-THRASHED AND STACK-THRASHED 



WHEATS. 



Table I shows in detail the results of the experimental milling tests 

 with the shock-thrashed and stack-thrashed wheats. Four days after 

 thrashing, on August 31, a sample of about 2 bushels of the shock- 

 thrashed wheat (lot No. 398) was milled in the experimental mill at 



[Cir. 68] 



