Why does grain spoil in your bin?

Grain spoils in your bin because it wasn’t properly conditioned for long term storage. Adequate preparation starts with cooling your grain down after harvest and conditioning to the optimum moisture content.

What happens in the bin when the grain isn’t conditioned properly for long term storage?

Let’s assume for this scenario, your grain has come off the field damp. With the onset of fall and early winter, colder air outside will cool the grain on the sides of your bin. Much warmer grain in the middle of your bin or core, will start the movement of warmer air upwards via convection currents. The greater the temperature difference between the grain along the side walls vs the core, the stronger the convection currents will be.


  1. Cold air flows down from the surface of the grain along the side walls
  2. The cold air flow surrounds the warm grain held in the core
  3. The grain from the core generates upward movement of warm air (convection)
  4. Cold air is pulled into the core from the bottom and is warmed up as it passes through the warmer grain
  5. This now warmer air picks up moisture and condenses when it hits much colder air at the top of the bin
  6. The moisture at the top of the bin begins to rot the grain becoming a haven for both insects and pathogens

How can you prevent this from happening?
Check out two articles we have published to help you mitigate this problem.

"When speaking to your sales rep, we learned a lot about the advantages of stiffened walls as well as how temperature monitoring and fan control can keep you from losing value on your grain."

Don Chapman (farmer)