The Best Barrel Cleaning and Storage Methods

nucitrus Barrels 1 Comment

Now that you have purchased the best barrel for your wine and spirits, you may be asking: what’s next?

You might believe that having high-quality barrels is enough to enrich your beer, wine or spirit, but there’s more to it.

To ensure optimal flavor, you need to clean and maintain the barrel. Even the best oak barrels must be aged well, rinsed, and dried completely to age liquor to perfection.

Although cleaning barrels seems daunting, it can be boiled down to few easy steps.

Here are the best cleaning and storage methods for your wine, beer, and spirits barrels.

Preparing Your Barrel

Before you start aging your beer, wine or spirit, it is recommended that you soak your barrel. This may seem odd, but water ensures that the barrel swells to prevent any leaks. Any holes can lead to rapid oxidation, and ruin the flavor of your wine.

The best way to prepare your barrel is to use hot water to soak the barrel. Using cold water is another alternative, but this takes a long time for the wood to swell.

Fill the barrel to about a tenth of its volume with hot water and move it around to wet all the insides. Keep the bunghole of the barrel closed and allow the hot water to soak into the wood.

Make sure to wet the outside ends of the barrel with hot water and let them soak for half an hour.

After your hot water soak is done, fill the barrel with cold water to check for leaks. Take your time with this process. You can soak for longer to make sure all holes are closed up.

Rinse and Repeat

After you have successfully aged your beer, wine or spirit, you need to empty out your barrel. Oak barrels can be used for up to 100 years if you clean them the proper way.

Make sure you clear them of any residue of liquor. Rinsing the barrel thoroughly prevents any mold from growing. To clean it, you should repeatedly rinse the barrel with clean water right after you’ve finished aging your product in the barrel.

You may see tartrates building up on the side of the barrel, but there’s no need to worry. This is just a combination of the natural acids in your wine crystallizing. An overnight hot water soak will take these right off your barrel.

Rinse until the water runs clear. That’s when you know that the barrel is completely clean of liquor.

Getting Rid of Mold

The water rinse is the best way to go.

If your barrel has a weird stench or discoloration, try using sodium percarbonate or sodium carbonate.

You should keep in mind that using these harsh chemicals wear down the flavors of the wood. Using sodium percarbonate or sodium carbonate every time you clean your barrel will make it bland and ineffective for aging product.

You should only be using these chemicals to clean mold and microbial build-up.

Mix a tablespoon of sodium percarbonate or soda carbonate per gallon of water to make a cleaning solution. Make enough solution to fill up most of the barrel. Swirl this solution around in your barrel to get rid of the mold or smell. You can also scrub residue off with this solution using a brush tool.

If mold grows on the exterior of the barrel, make sure to get rid of it. Mold seeps through wood and could ruin your barrel’s interior and your product.

Storage Preparation

After you’ve cleaned your barrel, dry it completely. If you want to refill it within a month or two of cleaning it, you can keep the barrel empty.

You need to light a sulfur burner inside the barrel to preserve the barrel. The presence of SO2 gas ensures that there is no mold growth. Warning – do not do this step if the barrel aged spirits.

Light the sulfur disc or stick and lower it into the barrel on top of a disc holder. You must light the disc and try to close the bunghole as quickly as possible. It is incredibly toxic to breathe in sulfur dioxide.

After waiting for five to ten minutes, bring up the sulfur disc and holder and remove it from the barrel. Close the bunghole immediately to seal the sulfur dioxide inside.


After you seal the bung, place the barrel in a dry and cool place.

Sulfur dioxide tends to escape over the course of two months. Check your barrel occasionally by opening the bunghole and sniffing it lightly. If the sulfur smell is gone, you should light another sulfur disc. This ensures that the barrel will be protected against mold growth.

SO2 tends to dry out a barrel. When a barrel is dry, it can get cracks on its surface and allow mold to seep inside.

You will have to put hot water into the barrel when you want to light up a new sulfur disc. Place some hot water into the barrel and let it wet all sides of the barrel.

After letting it soak, drain the water and dry the barrel completely. Repeat the sulfur disc lighting process.

Alternative Storing Method

If the water and sulfur disc process is too involved, you can also fill the barrel with a citric solution. This way, the barrel remains protected from microbial growth, and it remains moist.

Make a citric acid solution by dissolving 1 teaspoon of citric acid and 2 teaspoons of potassium metabisulfite in one gallon of hot water. Fill the barrel completely with this solution for long-term storage.

You can keep this solution in your barrel for six months. Sometimes you can leave it in longer.

Use Your Barrel for Life

Now that you’ve learned the basics of keeping your barrel in great shape, you should visit our Barrel Care page for more tips. You’ll be able to age wine, beer, and spirits easily!

An oak barrel of high quality should last longer than a lifetime.  Make sure you follow these steps to keep your barrel forever.

If you don’t have a sturdy barrel yet, check our shop for a variety of wine and spirit barrels.

Comments 1

  1. Hi, I recently re-discovered a 10g rum barrel in my basement that I had purchased in 2015 for aging homebrewed beer. I clearly forgot about it and it was sitting in the box it was shipped in this hole time. The box was not bagged inside this box, just padded with wrapping paper. I accept the barrel is likely dried out and needs a good hot water soak to swell and have any chance of holding liquid. Assuming I am able to get it to hold liquid, is there any concern with the integrity of the barrel interior? I see you mention just a PBW soak rinse will get rid of mold, but is that really all that is needed?

    Is there any way to assess if the mold was present and has since dried out or otherwise “died”?

    I have not opened the bung to check the interior yet.


Leave a Reply

Your email address will not be published. Required fields are marked *