How to Tell If a Wine Has Gone Bad

There’s nothing worse than opening a bottle of wine, anticipating a great pour, only to find it smells—or tastes—off. Whether you’re a casual drinker or a budding wine enthusiast, knowing how to identify a spoiled wine can save your taste buds (and your dinner plans). Wine is a living product that evolves over time, but sometimes it goes beyond its peak and becomes undrinkable. Here’s how to tell if your wine has gone bad and what causes it.

Common Signs of Spoiled Wine

1. Strange Odors

   • Cork taint (TCA): This gives wine a musty, damp basement or wet cardboard smell. Caused by a compound called TCA, it can taint even the best wines.

   • Oxidation: If your wine smells like cooked fruit, nuts, or even vinegar, it’s likely oxidized. Oxygen exposure leads to dull, flat aromas and an overall lifeless profile.

   • Volatile acidity: This fault can make wine smell like nail polish remover or vinegar due to high levels of acetic acid and ethyl acetate.

2. Off Colors

   • Red wine: If your red wine has turned a brownish brick color, it may be past its prime. While some aging can cause slight browning, significant color change signals oxidation.

   • White wine: Whites that have turned deep gold, brown, or cloudy (unless it’s a natural wine designed that way) may be spoiled.

3. Unpleasant Taste

   • If the wine tastes sour, sharp, or unusually flat, it may be off. A sharp, biting acidity without balance or a cooked, stale flavor are red flags.

   • In sparkling wine, if the fizz has disappeared (and it wasn’t meant to be still), that’s a sign the wine is over the hill.

4. Fizz in Still Wine

   • If a still wine suddenly has bubbles and wasn’t meant to, it may have undergone unintended secondary fermentation in the bottle. This can make it fizzy, cloudy, and sometimes sour.

Causes of Spoiled Wine

1. Cork Taint (TCA Contamination)

   Cork taint affects about 1–3% of wines sealed with natural cork. Even a tiny amount of TCA can ruin a wine’s aroma and flavor, making it undrinkable despite being safe from a health standpoint.

2. Oxidation

   Oxygen is wine’s friend in small doses but its enemy over time. Once exposed—either due to a faulty cork or after opening—the wine begins to oxidize, losing its freshness and vibrancy.

3. Heat Damage (Cooked Wine)

   If wine is exposed to high temperatures (like being left in a hot car), it can “cook,” altering the wine’s flavor and balance. Signs include a sticky cork, seepage around the neck, and stewed or jammy flavors.

4. Light Damage (Lightstrike)

   Prolonged exposure to light, especially UV rays, can degrade wine. This is why many wines come in dark glass bottles. Lightstrike causes wine to smell and taste off, often like wet wool or cabbage.

5. Microbial Spoilage

   Sometimes bacteria or unwanted yeasts sneak in, especially in low-intervention wines. This can lead to off smells like barnyard, sweaty socks, or rubber. While some wine lovers appreciate certain funky notes (like in natural wines), there’s a line between “interesting” and “spoiled.”

How Long Does Wine Last After Opening?

• Sparkling wine: 1–3 days (best if re-corked tightly or with a sparkling wine stopper).

• Light white/rosé: 3–5 days in the fridge with a cork.

• Full-bodied whites: 3–5 days, sealed and refrigerated.

• Red wine: 3–5 days, sealed; you can leave it at room temp if cool, or refrigerate for longer life.

• Fortified wine (Port, Sherry): 1–3 weeks after opening, as higher alcohol extends shelf life.

Storage Tips to Prevent Spoilage

• Store wine bottles on their sides (if cork-sealed) to keep the cork moist.

• Keep wine at a consistent, cool temperature—ideally around 55°F (13°C).

• Avoid exposing wine to direct sunlight.

• Use a vacuum pump or inert gas spray after opening to extend freshness.

What About Sediment or Crystals?

Good news: Not everything floating in your wine means spoilage. Sediment in red wine or tartrate crystals (like tiny glass shards) in white wines are natural byproducts of winemaking and harmless. Simply decant the wine to separate them if you prefer.

Trust Your Senses

The best tools you have for detecting a bad wine are your nose and palate. If something smells or tastes unpleasant and not as you expect, trust your instincts. While faults like cork taint or oxidation are easy to spot, subtle spoilage might take a bit of experience to identify.

Can You Drink Spoiled Wine?

Most spoiled wines aren’t harmful—just unpleasant. If it smells like vinegar or wet cardboard, it’s probably safe to sip, but you’ll likely want to pour it down the drain. However, if wine has mold or looks unusually cloudy with floating material (beyond harmless sediment), it’s best avoided.

Repurposing Bad Wine

Before tossing that off-tasting wine, consider using it for:

• Cooking: Slightly oxidized wine can still add flavor to stews, sauces, or marinades.

• Vinegar: If a wine has already turned vinegary, you can let it finish the process and make your own wine vinegar.

Final Thoughts

No one enjoys discovering a bad bottle, but knowing how to spot the signs can help you quickly decide whether to salvage or scrap it. By storing wine properly and being mindful of its lifespan, you can keep your wine experiences enjoyable and flavorful.