milled grain

How Long Do Milled Grains Last And How To Store Them?

dorian touly

Lifelong beer habitue and homebrew artisan

Without considering your expertise, your beer will only be as good as the quality of your ingredients. That means you need to buy the good stuff, but also store it properly.

We’ve seen craft brewers repeatedly tossing out their grains because they were swarming with small flies or worse.

Grains are super nutritious, and that means lots of microorganisms and insects love to feed on them.

Taking care of your grains is a priority.

They often represent a considerable investment because, unlike hops, you use lots of them. The good news is that taking care of your malted barley, wheat and other grains is easy.

First and foremost, you might want to buy your grains as you go.

Unless you’re already a medium-sized brewery fermenting a few batches a week, I recommend taking it easy. Source your grain from a reputable supplier every time you need it.

Grain bulks use quite a lot of space, and they’re a pain to move around — most craft brewers start in tight spaces, perhaps their garage, and have little room to spare.

If having a few bags of grain around is justified, you want to store them properly, though.

grain in bag
I usually buy milled grains just a few days before making the beer


What Happens to Grains in Time?

All grains are astoundingly resistant, that’s basically the reason why humanity thrived, because you could harvest wheat, rye or barley, and store the grains during winter.

The grains’ mortal enemies are:

  • moisture
  • light
  • heat
  • insects and rodents

brewing beer grains ennemies


Where there’s moisture, there’s mold and bacteria.

Insects come later, especially if they find an easy way in your containers.

And rodents, well, they’ll chew on everything, even plastic! So, keep an eye on them.

More often than not, your main problem will be weevils, beetle-like insects also called flour bugs.

The tiny black insects are harmless to humans and animals, but they will feed on your grain, while pooping, breeding and laying their eggs over it.

You probably don’t want to brew that.

If the grains are noticeably humid, you’ll want to throw them away.

Mold might be more harmful than insects.

Grains and flours can absorb odors from the environment, and that’s something to consider as well because they’ll taint your beer with foul smells.

Don’t store them near your cleansing products or other chemicals.


How Long Do Unmilled Grains Last?

Unmilled grains will last at least six months at room temperature, nine months if refrigerated and up to 12 months if frozen. Some home-brewing experts say grains can last for decades, while suppliers, like Maltwerks say, ‘Whole kernel grain can be stored for up to 180 days.’


When Is the Best Time to Mill Your Grains?

If you can mill them the very same day, you’re using them, then do so, but that’s not a reality for most brewers who buy milled grains instead of milling their own.

Which leads us to the next question.


How Long Do Milled Grains Last?

Once the grains are milled, they have a shorter lifespan.

Milled barley will last three months if kept at room temperature, four months if refrigerated, and six months if frozen. The same applies to adjuncts such as rice, corn and wheat. Only oats are a bit more fragile, so you’ll want to use them a month sooner in either case.

Everyone agrees grains, both milled and unmilled last for a considerable time, but it’s easy to see why you want to use them as soon as possible.

As a hobbyist home brewer, you probably don’t have conditioned refrigeration rooms or industrial freezers, so you better use your grains sooner rather than later.

dark milled grain
Grains for a stout ready to brew!

As long as you keep your grains away from its mortal enemies, described above, they will be fine.

Now that we’ve covered the risks of storing your grains inadequately, and how long can you expect them to last in prime condition, it’s time to review the most important things when storing your grains.


How to Store Your Grains

When storing grains, temperature matter. You should keep them at temperatures between 50° and 70° F (10° – 21 ° C) with the sweet spot at 64º degrees (17° C). A dark, well ventilated basement might be ideal, but you must watch out for the humidity levels.

The way you store your grains might be more important than where you keep them.

For starters, you’ll want to transfer the grains from their bulk bags to airtight buckets or sealed trash cans.

Try to leave as little air room as possible to minimize oxygen exposure.

Keep your airtight plastic containers at least ten inches above the ground to keep rodents away; they can chew through the sturdiest plastic containers.

Specialty grains, which you use less frequently and in lesser amounts, can be stored in gallon Ziploc bags easily, and you might be able to make room for them in your freezer.

If you live in hot, humid climates, you’ll have it a bit rougher. Hot and humid is far worse than just hot or just humid, so you might have to condition a storage area depending on where you live.

If you make your beer in cold climate regions, your grains will probably be a lot safer, since both rodents and insects are scarcer.


The Bottom Line?

Keep your grains away from heat sources, light and moisture, preferably in airtight containers away from scavenging animals.

When possible, refrigerate, or even better, freeze your grains.

If that’s not possible, then buy your grains as you go and keep a minimum amount at home.

Take care of your grains, hops and yeast.

Keep your equipment clean and organized, just avoid clutter.

Brewing beer is fun, but if you want great beer, you’ll have to act like a pro and keep things organized.

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