The best way to tell if your wine has gone bad

There's not much worse than preparing to unwind at the end of a long day with a glass of wine, only to pull that bottle of Syrah off the shelf or last weekend's half-consumed bottle of Pinot Grigio out of the fridge only to be met with the sinking suspicion that something just isn't... right. 

Maybe it's the smell — or a sip that doesn't taste too promising — but you can't quite tell. After all, wine is fermented grapes, so it's hard to tell sometimes if your wine has gone bad or you just haven't really acquired the palate to tell. It's not impossible to find out, though. Here's how to tell if wine is good to drink or if you're looking at a bottle gone bad.

How to tell if wine is bad without opening the bottle

Sometimes, wine goes off without being exposed to air at all. According to Wine Folly, temperature changes during shipping or storage, the introduction of microbes or bacteria during production, and even exposure to too much UV light can cause wine to go bad. These have a name — wine faults — and you can catch them before you even pop the cork. 

To tell if an unopened bottle of wine is bad, look for corks that seem slightly pushed out, which is a sign that the wine has been exposed to too much heat (non-sommeliers refer to this as 'skunked'). This might even cause the foil seal to bulge or break, according to Wine Folly. Other signs of bad wine are a discolored cork, a cork that smells like wet dog or mold, or wine that is already seeping out. These are signs of bacterial or microbe growth.

How to tell if an open bottle of wine has gone bad

Telling if an open bottle of wine has issues is going to be much easier, as most bottles of wine go bad through a process called oxidation, according to Wine Folly. Once it's exposed to air, wine's flavor starts to degrade. Let it go long enough, and the end result is bad wine. According to Popsugar, you want to look for wine that is cloudy or discolored, wine that has bubbles (but isn't a sparkling wine), and odors that are sickly-sweet, musty, or like vinegar. If you've gotten as far as tasting it and you think it tastes spoiled, you're probably right.

You can prevent your wine from going bad by storing it properly, and in many cases, you might even be able to return a bottle. The one thing you shouldn't do is settle for bad wine.