Thankfully, most wine faults will only be rarely encountered, the exception to that rule being a corked bottle of wine. Before we go any further, I must stress that a corked wine does not mean that is has pieces of floating cork in it. I used to believe that when I was younger and I would quickly flush down the sink any bottle of wine that had just the tinniest bit of cork bobbing around the bottle. Pieces of cork in the wine are harmless; just pick them out with fingers or a teaspoon!
A corked bottle of wine will occasionally turn up at restaurants and from retailers, there is nothing harmful about drinking it mind you, but it won't smell and taste too pleasant. Usually, it is easy to spot if a bottle is corked, the wine will have a damp, mouldy cellar smell and the fruit will be masked on the palate. To use the technical term, corked wine smells and tastes bloody awful! If your wine is corked then promptly request a refund, any reputable restaurant or shop should happily refund you or replace the bottle.
This enemy of wine enjoyment is caused by a compound called trichloranisole (TCA) which occurs after chlorine solutions used to sterilise corks and oak barrels come into contact with moulds in these items. This reaction creates TCA and voila, a corked bottle of wine. Corkiness is the most prevalent wine fault and can be eliminated to a certain degree by using screw-cap closures. However, a screw-cap bottle of wine can still be corked, as the TCA can occur in the barrel.
Another fault that crops up occasionally relates to oxygen, pure and simple. All of us will have encountered at least one oxidised wine in our lifetime, although it is more common with certain wine styles and regions (White burgundy anyone?) Oxidised is a generic description for wine faults resulting from absorbing too much oxygen usually because the cork is knackered of the wine has been stored without care. A boiling hot room is a sure-fire way of destroying your wine collection!
An oxidised white will usually have a dark, browned colour and smell flat or stale (sometimes bruised-apple smell), red wines will appear very faded and have bitter-sweet, caramel odours. Not completely unappealing but hardly what you paid for. They will taste tired and flat, if there was any fruit here, it left a long time ago!
So what else you must be wondering, could spoil my bottle? Although it is very rare today I probably should mention S0 2 (Sulphur Dioxide) overkill. This substance protects wine from oxygen and it's a normal part of the winemaking process. However, when there is too much present it can be sensed as a pricking sensation or burning at the back of the throat.
And then there is Hydrogen Sulphide, a true enemy of wine. Reduced Sulphur combined with exposure to the air produces that rotten egg smell or burning rubber. In its extreme form it produces mercaptans, an effected wine will smell of garlic, onion and sewage. Just send it back!
I hope this won't put you off your bottle tonight, as most of these faults hardly ever conspire to ruin a perfectly good bottle. Just make sure you exercise your rights as a consumer and send the bottle back immediately if you suspect any of the above. Don't do what my friend does, and suffer in silence.