Has Your Stored Wheat or Barley Finished Cooling?

Fan hours are a starting point

Your wheat or barley bin’s fan has run for hours, but has the grain finished cooling? Temperature readings give you a better answer than the clock alone. Following grain temperature or the temperature of air leaving the grain helps you track cooling progress and decide whether another cooling cycle is needed.

Cooling takes time to move through the grain

Aeration cools stored grain as a cooling zone moves through the bin. Starting the fan begins that process; completing it means the cooling zone has moved through the grain mass.

The time required depends on how much airflow the fan supplies per bushel of grain. University of Minnesota Extension gives a rule of thumb: divide 15 by the airflow rate in cubic feet per minute per bushel. At 0.1 cfm per bushel, the estimated cooling time is 150 hours.

That estimate helps with planning, but it does not confirm the job is finished. Extension says to measure the grain temperature or the temperature of air exhausting from the grain to know whether cooling is complete.

Use readings to follow progress

Start with temperature information you can already obtain safely, without entering the bin. That may be readings from installed temperature cables or an existing, safely accessible exhaust-air measurement point. This advice does not require buying a new monitoring system.

For routine grain checks, Extension recommends measuring and recording temperatures at several locations. Permanently installed temperature cables make that work easier. Keeping readings together lets you follow changes instead of relying on memory or a single number.

Two questions help keep the decision clear:

– Has the cooling zone finished moving through the grain?
– After that cycle, is the grain cool enough for the storage conditions ahead?

A completed cycle and a suitable storage temperature are related, but they are not the same decision. A bin can finish one cooling cycle and still need another when colder weather arrives.

Why cooler grain matters

Keeping wheat and barley cool reduces mold and insect activity. Extension reports that activity slows below 60°F and almost ceases below 40°F. Cooling slows these problems; it does not establish that grain is free of mold or insects.

Cooling also helps limit moisture migration. When warm grain remains in storage during cold weather, moisture can move from warmer grain toward colder areas, rewetting grain near the top of the bin and leading to spoilage.

These are reasons to follow the grain’s temperature as the season changes, rather than treating fall aeration as a one-time task.

Make the next decision from temperature

If the grain remains too warm after the cooling zone has passed through the bin, Extension recommends repeating aeration when colder weather arrives. Use a storage-temperature goal suited to your climate; its specific winter recommendation for northern Minnesota is regional, not a nationwide target.

For your next cooling check, review the safely accessible temperature readings you already have and note how they change through the cycle. Continue routine monitoring after cooling: Extension recommends checking stored grain monthly in cold weather and every two weeks in warm weather.

For the full explanation, read University of Minnesota Extension’s wheat and barley storage guidance, reviewed in 2018.

Discuss a grain sample test

Prepare grain for better storage

Good storage starts before grain goes into the bin. Processing grain with Metra equipment, including VDSC+ARC, helps prepare it for storage and supports better aeration. Tell Metra what grain you store and what problems you are having. We can help choose the equipment and settings for your material.