Even though drying conditions are excellent now, some producers may be faced with drying high-moisture or immature corn this fall. To minimize spoilage during drying, do not use natural air or low-temperature drying for corn with moisture contents of more than 21%, according to Ken Hellevang, North Dakota State University Extension Service grain drying expert. Natural air drying doesn't work well in late fall because the air's drying capacity is extremely poor at temperatures below about 35° F.

When outdoor temperatures average near or below freezing, Hellevang recommends cooling the corn to 20-25° F for storage this winter and finishing drying in early April. Natural air drying is the most energy- and cost-effective method of drying at that point.

Limit the corn depth to about 20-22 ft. to obtain the proper airflow rate for drying. An airflow rate of 1-1.25 cubic ft./minute (cfm)/bushel is necessary to dry the corn before deterioration occurs. Turn fans off during extended periods of rain, snow or fog to minimize the amount of moisture the fans pull into the bin.

Adding heat doesn't help dry wetter corn and increases drying speed only slightly. The primary effect of adding heat is reducing the corn's moisture content unless you use a stirring device.

If high-temperature drying, use the maximum drying temperature that won't damage the corn. That increases the dryer's capacity (bushels dried per hour) and reduces energy use. Removing a pound of water will require about 20% less energy at a drying air temperature of 200° F than at 150° F. Follow the dryer company's recommendation, but generally, drying temperatures should be 210-230° F.

"Be aware that excessively high drying temperatures may result in a lower final test weight and increased breakage susceptibility," Hellevang warns. "In addition, as the drying time increases with high-moisture corn, the corn becomes more susceptible to browning."