From cloudy wine to brown wine that should take a white, Les Kincaid explores what can go wrong with your wine at a restaurant, at home, or just about anywhere.
While it is a general truth that you get what you pay for, there are the odd occasions when the best vintage Bordeaux can be as disappointing as a rancid screw cap bottle of wine from a cheap and cheerful French supermarket. Luckily, this is a rare occurrence, but it still might help to know what is wrong with your wine, and what you can do about it.
Wine should be bright and clear, not cloudy (but opaque is okay). If your white has turned brown it isn't a good sign.
If wine comes into contact with air (in the glass or bottle) it starts to oxidize. A little oxidation is not a bad thing; it's what wine people call 'letting the wine breathe'. But too much oxidization and the wine will start to lose its aroma, especially any fruitiness. You'll also find that white wine will darken.
If the yeast is not completely removed it can react with any sugar that's left and the fermentation process can start again, making the wine cloudy and fizzy. Fine in the controlled conditions that create champagne, but not in anything else. What's more, the bottle may even explode!
This time it's bacteria rather than yeast, which is the culprit, making the wine taste like vinegar.
This isn't where you get bits of pieces of cork floating in the wine but rather where the cork - perhaps through a mold infection or a chemical reaction - tastes and smells moldy and dank. This aroma and taste is transferred to the wine.
Tartaric acid gives freshness to the wine but occasionally it can precipitate forming white tartrate crystals. These are unsightly but not dangerous and can be removed by decanting.
Sulphur is a preservative used to protect against oxidation and kill unwanted bacteria but now and again too much sulphur can be added producing a rotten-egg or burnt-match smell. If it smells disgusting you obviously won't want to drink it but what if there is just vague tang of something? Open the bottle and leave it for five to 10 minutes. This may clear it up. You may like to know that twice as much sulphur is used in a boxed wine as in bottled. This is because boxes are more porous and sulphur is used to counteract the effects of oxygen.
This is really a matter of taste. One man's delicious 'oaked' Chardonnay is another man's over 'oaked' rubbish. If you want to avoid the risk always look for 'unoaked' on the label.
And finally, never use an off wine, or wine that you wouldn't drink, for cooking - it will merely spoil the food!