Spotting faulty wines
There are several wine faults. Most come from poor winemaking or from defective materials, especially corks. Faults vary in intensity - some merely lessening the potential pleasure from a bottle, others making it undrinkable.
Not all tasters are equally sensitive to particular faults - some notice a corked wine in seconds, while others may pick up on too much sulphur.
Corked - the wine smells and tastes musty and sour. Caused by a fault in the cork whereby a chemical called TCA destroys the wine.
Oxidised - a wine that has had too much contact with oxygen. It has a sherry-like smell. Oxidised white wine is curiously dark in colour for its age while red is abnormally brown for its age. All wines gradually oxidise as they get older. This is an essential part of the ageing process. However, some wines are prematurely old. This may be due to poor handling of the grapes after they have been picked, faults in the winemaking or because the cork has provided an imperfect seal.
Over-sulphured - a wine that smells of burnt matches
a sour taste in the back of the throat. It will often leave you
foul headache the next morning. Sulphur dioxide is widely used
as a necessary
'disinfectant' in wine-making. Many winemakers now, however, try
as little sulphur as possible. Today sulphur levels are
lower than they were twenty or thirty years ago.
Hydrogen-sulphide - bad egg smells that come from winemakers not paying sufficient attention during fermentation. Equally, they can occur if the wine has not been racked adequately while it matures.
Unclean barrels ('barrel taint') - can give wine an unpleasant musty taste which is often very similar to a corked wine. Barrels, especially any that are empty for a while, have to be kept scrupulously clean to avoid tainting the wine. Where possible winemakers prefer to keep their barrels full with wine.
Acetic acid - common to all wines. In excess it will make the wine smell and taste vinegary.