Appearance Related Faults
A wine which looks cloudy when carefully poured from a bottle which has been allowed to stand for a few hours is probably faulty, though it may taste fine. Carelessly decanted wines and ones which have been shaken up before serving may also look cloudy of course.
Do not worry about the fine, dark film which is sometimes found within bottles of Australian red – it is simply the deposit – nor about the white crystals encountered at the bottom of some whites. Known as “Wine diamonds” in Germany, these are a natural tartrate deposit which would be far more commonplace if producers did not generally chill their white wines to precipitate them before bottling.
Any wine which looks brown, unless you know it to be of an advanced age, is probably past its sell-by date or has been oxidized by poor handling.
Smell Related Faults
If the stuff in your glass smells like sherry and does not describe itself as sherry or one of the rare sherry-like wines described on P. 43, it is oxidized. This could be caused by age, a leaky cork or storage in a warm place. Unless you suspect age to be the culprit, ask for a replacement. If it smells vinegary, this again could be a case of a poor bottle, though there’s a significant chance that careless wine-making could be responsible. Mustiness is another frequent problem. But before complaining, give the wine a chance to breathe; sometimes what older wine buffs used to call “bottle stink” will disappear after a few minutes’ exposure to the air. If the symptoms persist, you may have a wine which was matured in dirty wooden casks or one which is “corked”.
This last condition, often wrongly diagnosed on the basis of a few harmless crumbs of cork floating on the surface of the wine – the result of the cork breaking apart as it is pulled from the bottle – is caused by generally invisible, but sadly quite prevalent, types of mould. Corked bottles are recognizable from a smell which resembles a combination of state dried mushrooms and damp cellars which tends to intensify the longer the bottle is open. Cork wholesalers themselves admit that between one in 20 and as many as one in 12 corks may be more or less affected by this mould. Buying a pricey wine does little to lengthen the odds against getting a bad bottle – though there is little question that “agglomerate” corks, made from tiny chips glued together and used almost exclusively for cheap wines, seem particularly subject to mouldy smells and flavours. Ironically, research has shown that the most efficient way to seal a wine bottle would be with a screwcap, but since few wine buffs are ready to unscrew a bottle of Mouton Rothschild, go-ahead producers in California and Chile and supermarkets in Britain have instead switched to recently developed polypropylene corks.
Another fault you may encounter is the presence of some from of sulphur. Cough-inducing sulphur dioxide is common in recently bottled wines and most particularly sweet ones form the traditional areas of Europe (New-World wine-makers are less tolerant of it), while a gluey or a manure-like smell reveals unwelcome sulphur compounds in the wine. One way to check your diagnosis of these is to drop a copper coin into the glass and leave it in contact with the wine for a few minutes. Often, the copper will clean up the problem. Unfortunately, a bottle with one of these sulphur-related conditions is probably typical of a whole batch.
Thanks to modern technology, faults are becoming increasingly rare. Most are easy to detect by sight or smell.
So-called because excess contact with oxygen has spoiled their taste.
White Wines have a dull appearance, with a darker colour than normal for age/type: lacklustre straw to brown. Flat, stale smell; dull, sharp taste. Also called maderized.
Red Wines too have a dull appearance, browner than normal for age/type. Flat, stale nose with a "sweet and sour" or caramelly smell and taste.
Have a noticeable sour vinegar smell from the "volatile" acid: acetic acid, ie vinegar. Thin, sharp, sour taste.
Sulphur Related Faults
Sulphur di oxide
Pungent, acrid, suffocating smell, like a safety match on being lit; sharp, dry prickling sensation in throat on tasting.
Smell of bad eggs, rubber, garlic, rotting vegetation, with tastes to match. Also called reduced.
Smell of damp and mould completely dominates the bouquet and flavour of the wine. Nothing to do with fragments of cork in the glass, which are harmless.