By Angie Peltier
Iowa State University Extension Ag Engineering Specialist, Dr. Greg Brenneman, recently shared some information regarding cooling the grain that went into storage this year.
"In the past couple of weeks a lot of corn and soybeans went into storage with temperatures in the 60s. With grain this warm, moisture migration within the grain mass and spoilage can occur very quickly, even with fairly dry grain.
With average daily temperatures soon in the low to mid 40s, newly stored grain should be cooled down as soon as possible. While stored grain should be cooled to 30-40 degrees for winter storage, the sooner we get grain temperatures down, the better. Fans might need to be run several times during the fall to get grain down to wintertime storage temperatures.
The time required to completely cool a bin of grain depends on fan size. In general terms, a large drying fan will take 10-20 hours to cool a bin of grain. However, a small aeration fan can take a week or more to completely cool a full bin. In either case, it is best to measure the temperature of the air coming out of the grain to see if cooling is complete. It is also much better to error on the side of running the fan too long rather than turn it off too soon.
Now is also a good time to "core" each of your bins to remove fines that have accumulated in the center of the bin. When coring a bin after filling, remove about half the peak height for improved aeration. After coring, the top of the grain should be visually inspected to ensure an inverted cone has been created. If no cone is created, bridging of the grain has taken place and a very unsafe condition has been created. No one should enter the bin until situation has been safely corrected.
If grain is dried down to the proper moisture and correctly cooled, it should store very well through the winter. Even so, it is best to check stored grain at least every two weeks during the winter and once a week in warmer weather. To do a good job checking grain, inspect and probe the grain for crusting, damp grain, and warm spots. Also, run the fan for just a few minutes and smell the exhaust air for any off odors.