1. If The Wine Smells Bad, It Probably *is* Bad
Spoiled wine can smell like a lot of things. Unsurprisingly, none of them are good, so it’s actually an easy way to check for freshness. Sniff that bottle. Does it smell acidic? Or does its scent remind you of cabbage? Maybe it smells like a wet dog, old cardboard or rotten eggs. Or maybe it’s nuttier than you remembered, kind of like burnt sugar or stewed apples—that’s a sign of oxidization (more on that below).
If you’ve left a bottle of wine open for too long, it will probably also smell sharp, like vinegar. That’s because it’s basically been turned into vinegar by bacteria and air exposure. It probably won’t hurt you to taste it (the alcohol technically acts as a preservative), but we wouldn’t recommend drinking a glass. Don’t worry, you won’t want to.
2. Look For Changes In Texture And Clarity
Some wines are cloudy to begin with, especially unfiltered and natural varieties. But if you started out with a clear liquid and it’s suddenly cloudy, it’s likely a sign of microbial activity—gross. Likewise, if your once-still wine now has bubbles in it, it’s starting to ferment again. Nope, it’s not homemade Champagne. It’s sour, spoiled wine.
3. Watch Out For Oxidization Or Changes In Color
The minute you open a bottle of wine, you expose its contents to oxygen, and just like a slice of avocado or apple, it will start to brown (i.e., oxidize). If your pinot grigio is now more of a pinot brown-io, it’s still safe to drink, but it won’t taste as lively or as fresh as it was on day one. Red wines can oxidize too, turning from vibrant red to a muted orange-brown. Again, it won’t kill you to drink these wines, but you probably won’t like how they taste.