NOT WINEMAKING FAULTS
TCA or Cork Taint
This was once the most common fault with wines from around the globe. As you can probably guess, this fault is purely due to the quality of the cork used to seal the bottle. Now of course this only applies to wines with corks – you simply cannot find wines under screw-cap with TCA. Not all corks will have the components in them which affect the wines but about 1/10 will. Most wineries will spend a lot of money on getting top-grade corks to eliminate this problem – so really it is cheap wine stoppered with a cork that you should be worried about.
What does it smell/taste like?
TCA will give the wines a musty aroma of wet cardboard or old cereal-like aromas. Not only will it have these ‘off’ aromas but it will also reduce the bright fruit flavours of the wine.
Oxidation
Any wine that has spent some time in oak will be put through oxidation in a controlled setting – this gives pleasant aromas to the resulting wines, like nuts or caramel. Though excessive oxidation that comes about from a faulty seal on the wine bottle is a fault.
What does it smell/taste like?
Oxidation you can quite clearly see, the wines will be both dull in colour plus a tawny-brown colour (both reds and white are effected in this way). It will lack all primary fruit flavours and freshness, as well as sometimes effecting the acidity or structure of the wine. It should be noted that some wines will benefit from oxidation at lower levels as caramel, coffee and chocolate flavours can be beneficial and pleasing to wines. Though at high levels it will just be flat and unpleasant to drink.
Bad Condition
Wines that have been stored in areas of bright light or above room temperature for medium-long periods of time will most likely be in bad condition, or at least not showing at their best. The best conditions for wines are in a cool, slightly damp place in the dark. The absolute worst thing for wines is fluctuations in heat or light!
What does it taste/smell like?
Wines that are in bad condition will have lost its freshness and fruitiness. They will most likely also be slightly oxidised as well which would result in a change in colour.
TASTE