Do I need to smell the cork?
Clients sometimes ask me if it's really necessary to smell the cork when the sommelier presents it to them in a restaurant. The answer is no! Wine with a cork that smells a bit "off" could still be fine, and vice versa. When the sommelier hands the cork to you, just give it a quick look--if you see wine on the bottem of it, then it means the bottle has been stored on its side--a good sign, since oxidation can change a wine's aroma, flavors and color. If the wine is a bit older, you may see some cork damage (it might be drier, or cracked). This might not necessarily mean anything, so give the wine a taste to be sure.
Incidentally, about 5% of wines produced suffer from what is referred to as "cork taint." This is caused by the presence of TCA (2,4,6-trichloroanisole) in the cork, and it can give wine a musty, wet basement aroma and taste. If you encounter this in a bottle of wine, have the sommelier replace it, or take it back to the store.
Cork taint is one of the major reasons that winemakers are now using synthetic corks and screw caps. Synthetic corks do not provide as good a seal as real corks, but the technology is improving all the time. Many New Zealand and South African producers are embracing screw caps--inert gas is inserted into the top of the bottle to prevent oxidation, before the screw cap is applied. It's fine for wines that are meant to be consumed relatively young. It's also very convenient to take a bottle of screw-capped wine on a picnic--no corkscrew to worry about!