Beck's Blog

From Our Family Farm to Yours

Agronomy Talk: Storing Damaged Grain

Published on Wednesday, November 14, 2018

Click here for a downloadable version of this Agronomy Talk update

One of the unfortunate realities of farming is that sometimes we face a growing season that presents the right conditions for molds, rots, and diseases to move into our crops and severely damage grain quality.  To make things worse, some of these have the potential to produce mycotoxins, which can be toxic to livestock and significantly reduce the value of the crop. When a farmer ends up with damaged grain at harvest, the best thing to do is sell it as quickly as possible. However, sometimes due to the obligation to fulfill contracts or the ability to utilize bin space to capture carry in the market, it becomes necessary to store damaged grain. 

The following are some best management practices to maintain storage quality and reduce the risk of further deterioration once the grain is in the bin. Many of these are ideal practices for storing good quality grain as well, but they are especially important when storing damaged grain.


It is important to know what you are up against, and the best way to identify molds, rots, and diseases is to see them in the field before harvesting the grain. Proper identification is also important for knowing which toxins could potentially be present in the grain. Click here for more from Beck’s.

Identify ear molds in the field so you can harvest potentially problematic fields first.
Identify specific diseases so you can manage risk of damage and toxins.


Use the information you collected while scouting to determine which fields should be a priority to harvest. Poor grain quality will never improve. Since the best that can be done is to maintain the quality where it is, harvesting damaged fields earlier allows the possibility of stopping the progression of the disease. While it can be costly to artificially dry grain from higher moistures, often the cost is worthwhile. Increasing fan speed can blow lighter, diseased kernels out the back of the combine to minimize the amount of damaged grain that ends up in storage. 


Increase fan speed to keep damaged kernels out of your bin.

As soon as possible after harvesting, dry the grain to stop progression of the diseases, molds, or rots.  When working with damaged grain, it is important to dry the grain to a lower moisture than normal because lower moistures prevent fungi from growing and spreading disease or molds throughout a bin.  When storing damaged grain, it should be dried to 1% below normal storage moistures.


Timeframe for Removing Grain From Storage Ideal Moisture  Ideal Moisture
  Corn Soybeans
Mid to Late WInter (Before Spring Warm-Up) 14.5% 13%
Spring or Summer (After Spring Warm-Up) 13% 11%


Dry grain quickly and to lower moisture content than high-quality grain.
Moisture can allow molds to spread in the bin.


  1. Cleaning the grain and feeding out the cleanings is one of the best practices to improve storage conditions.  A cleaner will remove cracked kernels and other fine material that reduce airflow in a bin and are more susceptible to getting moldy in storage.  A cleaner may even be able to remove some damaged kernels.
  2. Store your damaged grain in your best bin with the best aeration and least potential for leaks.  If you don’t have any bins with full aeration floors, put some clean grain in the bottom of the bin first so that all of the damaged grain can be adequately aerated.
  3. It may be tempting to blend off damaged grain with good grain.  However, if the disease or mold spreads in the bin, it could damage the good grain that would have otherwise been just fine if not blended, resulting in more bushels of damaged grain.  Keep the damaged grain together to limit potential problems to the fewest number of bushels.  If you want to blend grain, do it as you are emptying the bins, not as you are filling them.
  4. Using a spreader to fill the bin improves distribution of fines and damaged kernels, which allows for consistent airflow throughout the bin.
  5. After filling the bin, be sure that the top of the grain is level because a peak can restrict airflow.  This can be done by using a spreader to fill the bin, or by removing some grain after the bin is filled to draw down the peak.

Avoid blending good grain with damaged grain — you’ll risk lowering the overall quality.
Use a spreader to fill the bin evenly- good airflow is essential to storing damaged grain


Moisture migration is a process by which some grain in a bin gives off moisture and it moves to other areas where it is absorbed by other grain.  This process is driven by inconsistent temperatures throughout the bin and results in wet pockets of grain where molds can grow and spread.  To prevent moisture migration from occurring, keep temperatures consistent throughout the bin through proper aeration.

  1. Start fans when average monthly temperature is 10-15 degrees below the grain temperature.
  2. Run fans long enough to move a cooling front fully through the grain, but no longer than necessary.  Bin and fan manufacturers may have specifications on how long the process should take based on the size of the bin and capacity of fans.
  3. If fans are blowing air upward into the bin, check the grain temperature 6-12 inches from the top of the grain.  When there is a significant drop in temperature, the cooling front has moved through and the grain is cooled.  If fans are pulling air downward through the bin, check the air temperature at the exhaust of the fan.
  4. Repeat this process for every 10-15 degree drop in temperature.  It usually takes two to three cooling cycles to cool the grain to 35-45 degrees, which is the ideal storage temperature for winter.
  5. When not using fans, cover them to reduce the chance of moisture entering bins and further cooling occurring during cold winter days.

Keep temperatures consistent throughout the bin.
Take your time when lowering bin temperatures after harvest and again in spring warm-up.


Check bins every two weeks for changes in grain quality.  Use a probe to pull samples from down in the grain to check moisture and temperature.  Look for condensation, crusting, wet areas, molds, insects, and hot spots.  Run fans briefly to check for odors.  If there are any signs of hot spots, run fans continuously until they are gone.  If you detect signs of grain quality further deteriorating, consider selling the grain.  It may be better to sell grain early for a lower market price than to allow grain quality to decrease to the point of being undeliverable or subject to severe quality discounts.

Check bins every two weeks. Sell damaged grain first.
No matter how well you manage the grain, quality is not getting any better.


As soon as you begin emptying bins to haul grain to its final destination, empty bins containing damaged grain first.  If possible, avoid storing it into spring to reduce complications caused by warming spring temperatures.

Repeat Aeration Process for Spring Warming:

As outside air temperatures rise, the grain will need to be warmed as well to avoid moisture migrations.  Follow the same process as cooling in the fall, only in reverse.  When the average monthly temperature is 10-15 degrees warmer than the grain, start fans and run them until the warming front has moved fully through the grain.  Check temperature to detect when the warming front has passed and shut down fans.  If hot spots are detected in the spring or summer and fans are needed to cool them, do not run fans if the outside temperatures are more than 10 degrees warmer than the average grain temperature.  Wait for cooler temperatures, such as at night or in the early morning, to run the fans.

Click here for a downloadable version of this Agronomy Talk update




Buschermohle, M. J., Pordesimo, L. O., & Wilhelm, L. R. (2005, June). Maintaining Quality in On-Farm Stored Grain. Retrieved from University of Tennessee Extension, PB1724:
McKenzie, B. A., & Van Fossen, L. (1995, June). Managing Dry Grain in Storage. Retrieved from Purdue University Cooperative Extension Service, AED-20:

Comments (0)Number of views (10245)
Mike Hannewald

Mike Hannewald

Other posts by Mike Hannewald
Contact author

Leave a comment

Add comment