A damp patch, a slow drip or a small puddle under the stand can make your stomach drop. The good news is that most barrel leaks are simple to fix once you know where they’re coming from. Different leaks need different fixes, and using the wrong one can waste time or make things worse.
This guide matches each type of leak to the right remedy. If you’d like the full step by step walkthrough, our guide on how to fix a leaking wine barrel covers the basics, and this post goes deeper on bung putty, swelling and the other fixes.
First, find where the leak is actually coming from
Wine runs along the outside of the barrel and can pool somewhere misleading. Dry the barrel completely with a clean cloth or paper towel, then watch it for a few minutes. Mark the spot where the wine reappears with a pencil or a piece of tape so you can track whether your fix has worked.
The usual suspects are the bung, the tap, the seams between staves, a loose hoop, or, less often, a crack in a stave.
Is it a leak or normal weeping?
A new barrel, or one that has been refilled after sitting low, will often weep a little as the staves swell back up. If it stops within a day or two while the barrel is kept full, that’s normal. It’s only a leak if it keeps going.
Fixing a leaking bung
The bung is the most common source and the easiest fix.
Remove it, dry the bung hole and look at the bung itself. If it’s cracked or badly worn, replace it. If it looks fine, reseat it firmly, as many bung leaks are simply a bung that isn’t fully down. If it still weeps, wrap the bung in a single layer of food safe silicone tape before putting it back in, which gives you a slightly wider seal. If a small gap remains at the join, bung putty can finish the job (see below).
How to use bung putty
Bung putty is for small gaps around the bung and the tap fitting. It is not the right fix for a crack in a stave or a leak along a seam.
Wipe the area clean and dry first, because putty will not stick to a damp surface. Work a small amount into the gap, press it in firmly and smooth it flush. Follow the instructions on the pack for setting time before you disturb it, and keep it on the outside so it never ends up in the wine. If the leak is still going after a few hours, putty isn’t the answer and it’s worth reading on.
Swelling the oak to stop a stave leak
Seam leaks are most often caused by dry staves that have shrunk and opened a small gap. The fix is to get moisture back into the wood.
If the barrel has wine in it: keep it as full as possible. The wine itself is what swells the staves, so top it up to the bung hole and leave it. Most seam leaks seal within 24 to 48 hours. If you can, position the weeping seam facing up so wine stays in contact with the gap.
If the barrel has been stored empty: fill it with luke warm water and check it regularly, topping up as the wood soaks in water. Once the leak stops, drain it fully and fill with wine. Never use water in a barrel that already holds wine, and never leave an empty barrel to dry out again.
If the seam hasn’t sealed after 48 hours of being kept completely full, contact us before trying anything else.
Fixing a leaking tap
If the leak is at the fitting around the tap rather than coming out of the tap itself, the seal has likely failed. A small gap can sometimes be sealed with bung putty on the outside. For anything more than that you’ll need to draw the level down below the tap and replace the seal, so get in touch and we’ll point you to the right fitting for your barrel.
Fixing a loose or shifted hoop
If a hoop has slipped or moves when you push it, the staves can flex and open slightly. Use a rubber mallet, never a metal hammer, and tap the hoop evenly back toward the belly of the barrel, working gradually around the circumference. If you’re not confident, ask us first, because forcing a hoop can crack a stave.
A cracked stave
A visible crack in the wood itself, rather than a gap at a seam, is not a home repair job. Contact us straight away. Continuing to use a barrel with a cracked stave risks a bigger leak and contamination of your wine.
After the fix
Once the leak has stopped, top the barrel back up to the bung hole with a suitable topping wine, as a barrel that has been leaking will have lost more than you think. Our guide to choosing the right topping wine will help you pick one. Check your SO2, particularly if the barrel has had significant ullage, using our guide to SO2 and your home barrel. And make a note of the date, the cause and the fix so you have a record if it happens again.
How to prevent leaks
Keep your barrel full, as that’s the single best protection. Keep it out of direct sun and strong draughts, particularly through the warmer months, and our summer barrel care guide has more on that. And check it regularly, since a small weep caught early is a five minute fix.
Frequently asked questions
Is the wine safe to drink if my barrel has been leaking?
Yes, provided it still smells and tastes right. A leak means you’ve lost some wine and probably increased your ullage, so top up and check your SO2 to protect what’s left.
Can I seal a leak with wax?
We’d advise against it without speaking to us first. Some products are safe on the outside of a barrel and others can taint wine. Bung putty made for barrels is the safer choice for small gaps.
Why is my barrel leaking more in summer?
Heat and dry air can shrink staves that aren’t kept swollen from the inside, and your level drops faster too. Keeping the barrel full is the best defence.
How long does it take for the oak to swell?
Usually 24 to 48 hours for a barrel that is kept completely full. A barrel that has dried out badly may take longer, so give it time and keep checking the level.
When is a barrel beyond repair?
A cracked stave, serious structural damage or a leak that persists after swelling and sealing means it’s time to talk to us. We’ll tell you whether it can be saved.
The takeaway
Most leaks come down to a bung that isn’t sealing or staves that need to swell. Find the source, match it to the right fix, and keep the barrel full. If it still won’t stop, give us a call and we’ll work it out with you.
Questions about your barrel? Our winemaking team is available Monday to Friday at wine@stantonandkilleen.com.au or (02) 6032 9457.
