The 3 Best Ways to Tell if That Bottle of Wine You Opened Has Gone Bad

Wine is delicious and can even be a heart-healthy drink that can limit your risk for Alzheimer's disease. Whether you enjoy a glass with dinner or just keep it on hand for hosting, chances are you've wondered if it can go bad. You may assume that wine is meant to age for years, but once you uncork a bottle of wine, a couple things can make a bottle spoil.

An open bottle of wine that has been properly resealed (either with the cork or cap the bottle came with or a reusable stopper) and put in the fridge or left out on the kitchen counter can undergo oxidation or secondary fermentation processes that may leave your wine tasting, looking and smelling like it's less than drinkable.

These helpful tips and tricks can help you decide whether your bottle of wine is ready to pour into a glass or should go down the drain instead.

How Long Does Wine Last?

All wines are different, and the shelf life of an open bottle of wine will vary depending on its blend, quality and flavors. However, a general rule of thumb is that an opened bottle of wine that has been properly resealed and refrigerated will last one week after it was opened initially. This recommendation applies to both white and red wines, as refrigeration slows down the oxidation process. (Pro tip: If you want to serve red wine that's been refrigerated, let it stand at room temperature for 30 minutes or so before drinking.)

Take a Look

If you just grabbed your open bottle out of the fridge and are wondering if it's still OK to drink, take a look before pouring a glass. The first thing to look for is a film inside the bottle (sometimes a residue will stick to the glass) or a cloudy haze in the liquid that wasn't there before. If the wine bottle is made of dark glass, pour a splash into a clear wine glass. This way, you can see if there have been any changes to how the wine looks. Some wines are naturally a little cloudy, so be sure to ask yourself if it looks different from when you first opened the bottle. A cloudy wine probably has developed some bacterial activity and isn't ideal to drink.

If your wine has changed color, it likely has been exposed to too much oxygen or light and is going to taste worse for the wear. Red wines may lose their vivid and rich color when they go bad. Keep your eyes peeled for wine that looks browner or duller than when first opened.

Another red flag is if your wine has developed small, fizzy bubbles. Unless it's a bottle of sparkling wine, this is not a good sign. Those little bubbles are an indication that the bottle of wine might have further fermented since being opened, which is not something you want to drink a whole glass of for the taste will be seriously skewed.

Take a Sniff

If looking at the wine for signs of spoilage is not giving you a clear answer, take a sniff. Wine experts say that wine that has gone bad will have one of three different smells.

Sometimes, opened wine can become contaminated with bacteria that causes it to spoil. If so, it usually develops an acidic, tangy smell similar to vinegar or sauerkraut. Does it smell like apples, cooked sugar or nuts? That's a sign that your wine has been open for too long and lost its flavor because of prolonged contact with oxygen, otherwise known as oxidation.

If you're opening a new bottle and catch a whiff of garlic or cabbage, this could be a sign that your wine got contaminated during production. While this is a rare occurrence, smelling fresh bottles is a good practice.

Take a Taste

If you did not catch a smell or appearance that seemed off, take a sip of wine to confirm if it has gone bad. If a wine has oxidized, it will likely have a fruitier and sweeter taste. Or if that additional fermentation process began while your wine bottle was left in the fridge, or on the counter, it may taste sour or bitter. So if your wine doesn't taste the way you think it should, it is best not to consume a full glass.

Can You Drink Spoiled Wine?

Wine that has gone bad isn't likely to harm you if you consume it. Unlike perishable foods, wine probably won't harm you if it's oxidized or has gone through a second fermentation. However, "bad" wine is not the ideal way to enjoy a glass, so ultimately it's all about taste.

How Can You Keep Wine Fresh?

Keeping wine fresh is pretty easy, and it comes down to tightly resealing the bottle after it's been opened—either with the cork or cap it came with or a reusable stopper. Refrigerate all bottles—whether the wine is white, sparkling or red—and they should stay good for up to a week.

Wine fanatics can purchase wine refrigerators or gadgets like wine pumps to keep their opened wine bottles fresher for longer. Wine experts also recommend pouring your leftover wine into a smaller glass container to minimize the amount of oxygen your wine comes in contact with.