Equilibrium Moisture Contents for Grain

Sam McNeill, Extension Engineer, University of Kentucky

Implications for drying:

• Grain will eventually reach the moisture levels shown in the tables when exposed to the corresponding temperature and humidity levels for long periods of time. This can occur in the field or in the top layers of a low-temperature bin dryer.
• Drying time will depend on the airflow rate through grain, which in turn depends on the depth of grain in a bin. The minimum drying rate for natural air drying is 1 cfm/bu, but this can take up to a month to dry the top layer depending on the grain and air conditions--during which time spoilage can occur.

Implications for storage:

Moisture Content Charts

Chad Lee, Extension Agronomist, University of Kentucky

A grain moisture chart was just updated for producers this fall. Dr. Sam McNeill calculated the Equilibrium Moisture Content (EMC) for corn, soybean and wheat. The charts identify the moisture that each seed will approach at a certain air temperature and relative humidity. For example, corn will approach 11.3% moisture content at 70 degrees Fahrenheit (21.1 degrees Celsius) and 50% relative humidity. Soybeans will approach 8.8% moisture content at 70 degrees Fahrenheit and 50% relative humidity.

Click here for the EMC chart.