Identifying a Faulty Wine
The winemaking process has become much better understood over the last few years, and as a consequence, there are far fewer faulty wines in the shops than ever before. However, faulty bottles do occasionally crop up, and so it's good to be aware of the telltale signs that will indicate a poor wine.
Visual Checks
The colours of wines vary according to their grape variety and the climate in which they were made. If you have a white wine with a brownish-yellow tinge that you expected to be pale, or if a young red has a brownish tinge, then it's probably oxidised, and will taste dull and flat.
Whatever its colour, wine should be clear and bright. Bacterial spoilage is often indicated by cloudy wine, but these days this is extremely uncommon. However, try not to mistake cloudiness with shaken-up deposit. A mature red wine that has developed a dark, powdery or gritty deposit should be stood upright for a day to let this sediment settle, before decanting.
Never buy a bottle where the top of the cork doesn't sit flush with, or below the level of, the mouth of the bottle. A cork protruding from the bottle is a potential sign of a maderised (cooked) wine. You should also check that the level of wine in the neck of the bottle is not too low. Although there's always some variation, most wine levels should be well into the neck.
Aroma Checks
| Odour | Description |
|---|---|
| Sherry | If you have a wine that smells like sherry, then it has probably oxidised. Only sherry should smell like sherry. |
| Vinegar | A wine smelling like vinegar has been exposed to oxygen, and is turning into something suitable only for cooking with. |
| Burnt matches | This is due to sulphur dioxide, the winemaker's all-purpose disinfectant and antioxidant. This particular fault is mainly to be found in young cheap white supermarket type wines. If the smell on opening a bottle is overpowering, don't drink it, but leave it for 10 minutes and it will usually disperse. |
| Rotten eggs | This is the smell of hydrogen sulphide which can form during fermentation and is a sign of poor winemaking. Try leaving it to breathe for a few minutes - it MAY clear up. Unfortunately however, the wine will be irredeemable, and you'll probably have to throw it away. |
| Mouldy or musty - like damp cardboard | This indicates a corked wine, caused by a cork contaminated with TCA (2-4-6 Trichloroanisole), which has migrated into the wine, causing taint. If the wine is only partially affected it will merely dull the aroma and flavour of the wine. If the wine smells musty for any other reason, it may be cured by leaving it to breathe for a little while. However, if it is truly corked, you will have to throw it away. |
Taste Checks
| Problem | Cause |
|---|---|
| Slight almond flavour, musty or lacks freshness | The wine has maderised: the alcohol has oxidised to acetaldehyde. The wine has been allowed to get too warm and has acquired a cooked, toffee-type flavour. It will probably have also turned slightly brown. |
| Dull, stale and flat | Oxygen has been absorbed into the wine, caused by too much exposure to the air. This oxidation results in a dull wine lacking in fruit. Instead of tasting fresh and fruity the wines lose their aroma and appear stale and flat. |
| Sour | The wine has been over exposed to air and has begun to produce acetic acid. Eventually it will turn into vinegar. |
| Prickly sensation | The wine has probably undergone secondary fermentation within the bottle, caused by residual traces of sugar and yeast left in the wine after bottling. The wine develops an unpleasant 'prickly' taste that should not be confused with 'pétillant' characteristics associated with healthy, sparkling wines. |
Whenever you spot a faulty wine, don't be afraid to return it to the shop, or draw it to the attention of the wine waiter. You should be offered a replacement straight away.
However, you should only a return a wine if it's faulty - never because you simply didn't like it. The only exception to this rule is if it was recommended by your waiter, whose description of it was wildly inaccurate.
