HEATING GRAIN IN STORE 293 



Heating of Grain in Store. The duties of an elevator superin- 

 tendent extend beyond the receipt, storage, and final transmission of a 

 certain amount of grain. In order to be able to keep the grain received 

 in good condition during storage, and to be able further to send it out 

 in even better condition, if possible, he should recognize as the grain 

 comes in just what kind of treatment it will require. In locating heated 

 grains, a "tryer" is used or the bin is "drawn." Usually large accumu- 

 lations of dust should be watched for closely. In moving or changing 

 grain in bins, the weather should preferably be dry and cool. Warm, 

 moist air, when allowed to come in contact with moving grain, may 

 spoil it even if previously dry. 



Corn which dried on the cob in the crib on the farm or at the local 

 elevator, shows little tendency to heat, except during the germinating 

 time in June, when care should be taken to withhold moisture from 

 it. "Winter shelled" corn keeps as long as cold weather lasts, but 

 when spring opens up it should be sent to the consumer at once, as 

 it is almost certain to heat. 



Grain in a heated condition loses rapidly in weight. The Shippers' 

 Manual of the Chicago Board of Trade for 1907 reports a single car- 

 load of hot corn shrinking 3,600 pounds. The Chicago Board of Trade 

 Weighing Department has frequently weighed cars of hot corn on 

 railroad track scales, day after day, the loss of weight being from 50 

 to 100 pounds per day per carload. 



Professor L. G. Michael, Chemist of the Iowa Agricultural Experi- 

 ment Station, says that "the heating occurs when grain originally in 

 a moist condition is put in bulk, thereby preventing it from drying 

 out and consequently subjecting it to attacks of fermentative bac- 

 teria, or cells similar to yeast cells. All chemical changes of this kind 

 generate heat which, in time, will raise the temperature to such a 

 height that oxidation by the air sets in. The oxidation may be so 

 rapid as to cause spontaneous combustion. The heating is due almost 

 entirely to fermentation which attacks the starch, changing it first 

 to alcohol and later to acetic acid. If heating is continued for any 

 length of time a decided loss of starchy matter results from the con- 

 version of the starch to alcohol with, of course, more or less impair- 

 ment of the unconverted starch. The matter of damage through 

 heating is one of degree, from almost no harm, through slight rises 

 in temperature, to almost complete ruin when fermentative changes 

 are allowed to reach any advanced stage." 



