Wine Gone Bad

Despite wine making having improved over the years, and with advanced storage and shipping methods, approximately 5% of all wines still arrive bad (to some extent) at the dinner table. How do you spot wine that's gone bad?

1. Corking

Even if high-tech plastics are available today, many wine bottles still come with a cork. Corks come from Mediterranean trees. They're lightweight, resistant to airflow and disease, and they're flexible and look nice.

However, corks are subject to microorganism attacks. There are certain fungi that can get into the wine even if it's tightly corked. These fungi can produce TCA (1,2,4-trichloroanisole), a compound that causes the wine to taste or smell bad. The odor is very similar to mushrooms, unwashed socks, or wet cardboard. The taste may be better or lacking in fruitiness.

2. Cooking

Wine can literally travel hundreds, if not thousands, of miles -- from the vineyard to restaurant or homes. About 5% of wine is spoiled because of excessive temperatures. When liquids are subjected to high temperatures, they expand, so when wine is heated, it can push the cork up. When the wine cools down, air seeps in. And if the temperature is high enough, the wine gets cooked -- literally. Cooked wine that's supposed to have a fruity flavor will taste like stewed prune. A quick way to tell if your wine has been cooked (without tasting it) is to look at the cork and the wine inside. If the cork sits above the bottle's lip and the liquid inside is too close to the base of the bottle's neck, don't count on your wine to taste good.

3. Oxidation

Corks can shrink or crack when wine is improperly stored. Too much heat or cold and the wrong humidity levels can cause a good wine to go bad. All these will cause the air to infiltrate the bottle, causing oxidation. While air is necessary in aging wine, air can spoil a perfectly good wine if there is too much of it interacting with the wine at any given time. Wine has gone bad if it has a fruitless taste and bears resemblance with old Madeira.

4.  Sulphur

Wine makers use sulphur to stabilize wine. However, in excess concentrations, it can cause an undesirable flavor and aroma in wines. You can tell if your wine had way too much sulphur if it has a mothball smell or the odor of burned matches.

5. Refermentation

In some rare cases, dormant yeast can remain in the wine, causing additional fermentation to occur while the wine is in storage or in transport. For instance, champagne undergoes deliberate refermentation in the bottle. For non-sparkling wines, though, refermentation is a no-no.