A good wine can be an amazing experience. A bad wine, however, is just the opposite. Telling the difference between the two is critical for your enjoyment.

Visual Clues

There are a few tell-tale signs of a wine gone bad that you can see just by looking at the bottle as well as a glass of wine.

1. The cork is pushed out of the bottle.

Photo by: Seth Anderson

A cork that is sticking out of the bottle and hasn't been tampered with is a sign that the wine has been exposed to extreme heat. The nitrogen inside the bottle has expanded and pushed the cork out.

2. The cork of an unopened bottle has wine stains around the perimeter.

This is another sign that the wine may have been exposed to excessive heat. During the exposure the wine actually went around the cork and seeped out the end of the bottle.

3. The cork is deteriorating.

If you look down at a cork in the bottle and the top of the cork has started to crumble and fall out your wine could be bad. Cork does break down after a while. When you see signs of this on the outside of the bottle you know that the same thing could be happening on the inside of the bottle.

4. Red wines that are brick-red or orange in color.

A young wine will have a reddish-purple color. As wine ages it will take on a orange-red hue. This is due to exposure to oxygen. However, if you're drinking a wine that is only two or three years old and is already  showing an orange tint you may have an over oxidized wine on your hands.

Olfactory Clues

Your olfactory system, or sense of smell, is another tool you can use to determine if your wine is bad. The best indicator:

1. Wine should smell like wine.

If you're picking up much beyond the smell of wine you could be in for a bad glass of wine. Smells such as vinegar, sulphur, or burnt rubber all point to something having gone wrong in the chemistry of the wine.

Likely if it smells this bad it will taste just as bad. This isn't always the case so before you pour the wine down the sink be sure to take a sip.

Taste Clues

When it comes to taste spotting a bad wine is a bit easier. However, you must learn to differentiate between a wine that is trully bad and one that you simply don't like. The following tastes will tip you off for certain.

1. Mold

A moldy taste is always a good indicator that somethings wrong. Some also describe a moldy taste as rot. Either way if you're getting mold on the palate, pour it out.

2. Wet Cardboard

Another unpleasant taste is wet cardboard or newspaper. This can be a result of a bad cork or a wine that has become "corked".

Know that this taste takes time to develop. If you're opening a bottle of wine and a few pieces of cork fall into it its not necessarily corked. Just fish out the pieces and enjoy. For a wine to become "corked" takes much longer than the few minutes your wine may have been in contact with pieces of cork.

3. Cooked Flavors

If you're picking up flavors that have a cooked or baked quality the wine was likely subjected to excessive heat. The wine will also be somewhat flat or seem old.

4. Chemicals

Any chemical tastes are a good tip that its time to pour your drink down the sink. Common chemical tastes are rotten eggs, burnt rubber, or rotten garlic. Unless you enjoy these flavors don't force yourself to drink any more.

5. Vinegar

The natural evolution of grape juice is from that of a pure juice to alcohol through fermentation and finally to vinegar through oxygen and further fermentations. Winemakers ferment grape juice but aim to stop this evolutionary process before vinegar is produced. Sometimes this process can continue in the wine after bottling. If you're picking up any vinegar tones don't drink it.

6. Bubbles in Non-bubbly Wine

Often this can happen with red wines that have not undergone a malolactic fermentation, also called a secondary fermentation. The details of this fermentation are not important. Some wines undergo this process and some don't.

Wines that don't undergo malolactic fermentation in the winery are at risk to do so once bottled. Because the gas produced during the process is not free to leave the bottle it is stored in the wine itself and manifests as bubbles. Drinking a fermenting wine is not a pleasant experience, pour it out.

Now you know what to look for when tasting wines. If you suspect that a wine is bad at a restaurant, have the waitor or sommelier have a taste as well. If it is bad they should replace your glass.

Photo by: Seth Anderson