Many farmers put grain in the bin wetter than normal last fall and were somewhat rescued by the cold weather that allowed them to hold cold grain in storage. As spring starts to bring warmer temperatures, grain held through winter at a high moisture content should be dried or marketed as soon as possible to prevent quality loss and mold growth. 

Iowa State University Extension ag engineering specialists Kristina TeBockhorst and Shawn Shouse point out that drying high-moisture corn requires extra care, especially in spring. They offer the following recommendations. 

Monitor grain condition and act fast if hot spots, a musty or moldy smell, or elevated carbon dioxide levels (above 600 ppm and rising) are observed. Grain held during winter at a very high moisture content (above 20%) may have already used its safe allowable storage life. For this grain, it may not be advisable to attempt to store it any longer after drying it this spring. Observe the allowable storage time for grain as recommended by ISU grain quality experts in this recent blog post and be sure to account for a shorter allowable storage time with low test weight and low-quality grain. 

Don’t wait to dry wet grain 

Wet grain should be dried as soon as spring temperatures start to warm. Conditions become suitable for natural-air and low-temperature bin drying when average daily temperatures are above 40 degrees F. The air dewpoint temperature gives a good indication of whether air has much capacity to dry. A 20-degree difference between the air temperature and the air dewpoint temperature indicates good conditions for drying. See details about natural-air and low-temperature bin drying at this website. 

Do not warm grain that is already dry if you intend to keep storing it. Instead, run aeration cycles in cool weather to maintain grain hours, while an aeration fan will take close to a week to cool a bin. Estimate the time to cool a bin with your size fan. See temperature below 40 degrees. The dewpoint temperature tells you about how cool grain will get during aeration. Check this recent blog post.

for details. If grain temperature is well below freezing, such as 20 degrees, then gradually warming it to just above freezing may prevent excessive condensation and frozen chunks this spring or summer. 

“With the potential for poor-quality grain in the bin, it’s especially important to use good grain safety practices,” TeBockhorst says. “Poor-quality grain can cause problems such as surface crusting, hollow spots in the grain mass, grain that won’t flow when unloading and sidewall buildup in the bin. Do not enter a bin if any of these occur. Instead, attempt to work on the grain from above by poking and prodding it. If you have good-quality grain and you must enter a bin, have an observer with you, use a life harness, and lockout-tagout grain equipment to keep it off.”