You pull out the bung, lower in your wine thief, take a sniff... and something's off. Sharp, chemical, almost like nail polish remover or acetone. It's not the rich, warming aroma you were hoping for. Don't panic. This is a known fault with a name, a cause, and in most cases, a fix.
What is that nail polish smell?
The culprit is volatile acidity, or VA. Specifically, a compound called ethyl acetate (the same solvent found in nail polish remover) which forms when acetic acid in your wine reacts with alcohol. At low levels, VA can add a subtle lift to a wine. At higher levels, it becomes that sharp, solvent-like smell that tells you something has gone wrong.
A small amount of VA is present in almost every wine and barrel. The question is whether it's crept past the threshold where it becomes a problem and why it got there.
What causes VA to develop in a home barrel?
VA builds up when bacteria get access to oxygen in the presence of residual sugar or alcohol. In a home barrel, the most common causes are:
- Ullage left unchecked. When your barrel level drops and you don't top it up, the air gap above the wine exposes it to oxygen and creates conditions where acetic acid bacteria thrive. If your barrel has been sitting low for a while, here's exactly what to do.
- Irregular topping up. Going months or years without topping up is one of the most common reasons VA develops in home barrels.
- Low sulphur dioxide (SO2) levels. SO2 is your barrel's protection against spoilage organisms. When levels drop, bacteria have free rein. Our guide to SO2 and your home barrel explains how it works and how to stay on top of it.
- Contaminated equipment. A dirty wine thief, bung, or funnel can introduce the bacteria directly into your barrel.
How bad is it? Can it be fixed?
This depends entirely on the level. VA exists on a spectrum. At low to moderate levels, where you can smell it, but the wine doesn't taste unpleasantly sharp, you have options. At high levels, where the wine tastes sharp and vinegary as well as smelling like nail polish, recovery is much harder.
The most reliable way to know where you stand is to send a sample to us for analysis. Our winemaking team will measure your VA level precisely and tell you whether it's within a salvageable range or whether intervention is needed.
What to do right now
If you've detected a nail polish smell, here's what to do immediately:
- Stop drawing off wine from the barrel. Don't add more wine either until you know where things stand.
- Check your SO2. If you haven't added sulphur recently, a measured addition can slow or halt VA development.
- Send a sample for analysis. This gives you a precise VA reading and a personalised plan for what to do next.
Can you reverse VA once it's developed?
Unfortunately, you can't remove VA from wine once it's there. No home remedy will neutralise it. What you can do is stop it progressing further with proper SO2 management and topping up, and in some cases blend it down with a fresh topping wine that masks the VA character. This is something our winemaker can advise on specifically once we've seen your sample results.
The good news is that fortified wine, with its higher alcohol and sugar content, is more resistant to VA development than table wine. If you've caught it early, the damage is often manageable.
How to prevent it happening again
- Top up before your barrel drops below three-quarter full. Don't wait.
- Check your SO2 levels at least once a year, more often if your wine is ageing in a warm environment.
- Keep all equipment scrupulously clean. Rinse your wine thief with a sulphite solution before use.
- Send a sample for analysis every 12 to 18 months so you have a clear picture of where your barrel stands.
If your wine has come back flat or dull alongside the VA smell, read our post on why barrel wine tastes flat and what to do about it — the two issues often develop together and the fix for one usually addresses the other.
Frequently asked questions
Is it safe to drink wine with a nail polish smell?
Low levels of VA are harmless. Many wines have trace amounts and are perfectly safe to drink. However, if the nail polish smell is strong, the wine will taste unpleasant and isn't worth drinking. It won't make you sick, but it won't be enjoyable either.
How quickly can VA develop?
VA can develop in weeks if conditions are right, particularly when there's significant ullage, low SO2, and warm temperatures. In cooler, well-maintained barrels it can take months or years before it becomes noticeable.
Can I just pour it out and start again?
If VA levels are very high and the wine is unpleasant to drink, starting fresh is an option. Before doing that, get a sample analysed. Sometimes what smells alarming is still within a recoverable range. We'd rather help you salvage it than see a good barrel go to waste.
What does moderate VA actually smell like?
At low levels it's a faint sharpness or 'lift' at the top of the aroma. As it increases it becomes more recognisably vinegary or solvent-like, that nail polish or acetone character. At high levels it will also taste sharp and acidic on the palate. If you're not sure whether what you're smelling is VA or just the normal development of your barrel, get in touch with us. We're happy to talk it through.
