A hot, dry harvest often means grain comes off the combine at a safe moisture content. That’s great news, but it doesn’t necessarily mean it’s ready for storage.
Even dry grain can carry a lot of field heat. If it goes into store at 25°C or 30°C and isn’t cooled quickly, it creates the ideal conditions for insect activity, moisture movement and a gradual decline in crop quality.
In other words, dry grain still needs cooling.
Why does grain temperature matter?
Insects love warm grain.
Grain weevils, beetles and other storage pests become far more active as temperatures rise. Above 15°C, insects can reproduce quickly. At 25°C or more, a small infestation can become a much bigger problem in a matter of weeks.
Cooling grain as soon as possible slows insect activity and can reduce the need for remedial treatments later in the season. Heat reduces grain quality
Grain doesn’t stop respiring once it’s in store. The warmer it is, the faster that process continues, potentially leading to:
- Weight loss
- Reduced germination
- Lower crop quality
- Further heat build-up within the grain bulk
The longer grain stays warm, the greater the risk.
Dry grain can still develop moisture problems
It’s a common misconception that dry grain is problem-free.
As warm air rises through the grain bulk, it can condense when it reaches cooler areas near the surface. That creates damp patches where mould, caking and hot spots can develop.
That’s why regular temperature monitoring is just as important after harvest as it is during it.
What temperature should grain be?
For safe storage, grain should be cooled to below 15°C as soon as conditions allow.
For longer-term storage, aim for below 10°C.
Don’t wait until the store is full before switching on the fans. As soon as each ventilation pedestal is covered, begin cooling to start removing field heat straight away.
Six tips for more effective grain cooling
- Start ventilating as soon as each pedestal is covered.
- Run fans when the outside air is at least 4°C cooler than the grain.
- If you have fewer fans than pedestals, move them around the store regularly.
- Check beneath pedestal top caps for condensation. If you find any, move a fan to that pedestal immediately.
- Keep airflow consistent. Choose either blowing or suction and avoid switching between the two.
- Monitor temperatures throughout the store to identify areas that are cooling more slowly.
Is it worth investing in more fans?
In many cases, yes.
Adding more fan capacity can reduce cooling times and make harvest much easier to manage, especially during busy periods.
With additional ventilation costing from around £2 per ventilated tonne, it can be a relatively small investment compared with the potential cost of insect damage, mould, reduced quality or rejected loads.
Once installed, that extra capacity is there to protect future harvests year after year.
Try our simple crop cooling calculator today – Simply enter your requirements below, and we’ll calculate the best crop cooling solution for your needs and storage space, including any limitations that you have.
Keep your grain cool. Protect its value.
Evans & Pearce supplies a complete range of grain cooling and monitoring equipment, including:
- Grain temperature probes
- Pedestal ventilation systems
- High-performance cooling fans
- Differential temperature controllers
- Ventilation upgrades for existing stores
Don’t assume dry grain is safe grain.
Remove field heat early, monitor temperatures regularly and protect the quality and value of your crop from the moment it enters the store.
