Every wine drinker eventually faces the suspicious bottle: the white that has been open a week, the red from the back of the cupboard, the gift that spent a summer in a hot car. Is it still fine? The good news is that wine tells on itself quickly, and you need nothing but your senses to catch it.
First, the Reassuring Part
Bad wine is not dangerous wine. Alcohol and acidity make wine hostile territory for harmful bacteria, so a spoiled bottle will insult your palate, never your health. The worst outcome of a sip of vinegary Merlot is a grimace. That should make you braver about the sniff test, which is where every check begins.
The Five Signs
1. It smells of vinegar or nail polish remover. Acetic acid bacteria have been at work, usually because oxygen got in. This is the classic fate of a bottle left open too long; our guide to how long wine lasts after opening sets the timelines.
2. It smells of damp cardboard or a musty cellar. That is cork taint, the fault behind the term “corked”, and it can strike a brand-new bottle. The wine smells muted and papery, and it will not improve. Blame the cork, not the wine.
3. It has gone brown or hazy. Some browning is natural in aged wine, but a young white the colour of straw turned deep gold-brown, or a red gone brick and murky, points to oxidation. The flat, sherry-like smell will usually confirm it.
4. It tastes cooked or jammy in a tired way. Heat damage, sometimes called maderisation, comes from hot cars and sunny windowsills. The fruit tastes stewed and the wine feels flat. Storage is the culprit; our wine storage tips stop it happening twice.
5. It fizzes when it should not. Gentle prickle in a still wine means a second fermentation started in the bottle. A few styles, like Vinho Verde, carry a deliberate spritz, but in a supermarket red it is a fault.
A full tour of these and rarer problems lives in our wine faults guide.
What Is Not a Fault
Do not pour away a good bottle by mistake. Crystals on the cork or in the glass are harmless tartrates, wine diamonds, not glass. Sediment in older reds is natural; decant and carry on. A just-opened funk in some wines blows off after ten minutes of air. And a screw cap, as we have said before, tells you nothing bad at all.
Keeping Wine from Going Bad
Most spoilage is self-inflicted: recork promptly, refrigerate opened bottles (yes, even red), keep unopened wine cool, dark and lying down. Our guides to keeping wine fresh after opening and recorking a bottle cover the technique. And for the bottle you are saving for someday, remember wine has a lifespan even when perfectly stored: the drinking window checker tells you when someday is.
Frequently Asked Questions
How can you tell if wine has gone bad?
Trust your nose first: vinegar, damp cardboard, nail polish remover or a flat, cooked smell all signal a problem. Then look, browning in a young white or a hazy, murky colour is a warning, and unexpected fizz in a still wine means trouble. If it smells wrong, it will taste wrong.
Can bad wine make you sick?
Spoiled wine is unpleasant, not dangerous. The alcohol and acidity prevent harmful bacteria from surviving, so a corked or oxidised wine will offend your palate rather than your stomach. Sniff it, wince, and pour it away with a clear conscience.
How long does an open bottle of wine last?
Roughly three to five days for most wines if recorked and refrigerated, less for delicate old reds, longer for fortified wines. Sparkling wine fades fastest, usually within a day or two even with a stopper. When in doubt, smell it before you pour.
Explore with Sommo
The best defence against mystery bottles is a memory that never fades. Log every bottle in Sommo’s cellar and the app tracks when each one should be opened, so nothing lingers past its best. Scan a suspect label with the AI scanner to see how long its style is built to last before you commit to pouring.
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