Wine Steward Etiquette
After you've ordered, your server will bring your bottle to the table and show you the label to ensure that it is the wine you ordered. Pay attention: it's easy for wines to get mixed up because they're often retrieved by bin number, not by name. Also, note if the wine label is more than an inch or so below the cork. If so, it's likely that the cork is defective, in which case you should mention the "low fill" to the wine steward.
Once you've approved the selection, your server will open it for you and offer you the cork to examine. Don't sniff it: just make sure it doesn't look horribly dried out or moldy.
Next, the server will pour a small amount of the wine into your glass. Holding it by the stem, and keeping the glass in a contact with the table, swirl the wine a little bit. Take a sip, hold the wine in your mouth for a moment, purse your lips, and inhale gently. You should experience an intense – and hopefully pleasant – aroma. Slosh the wine around in your mouth and explore its flavors (this is called "chewing") before swallowing.
After the wine has passed your inspection, the server will pour it into the glasses until they are about half-full. This process should be repeated with every bottle you order, even if you order the same wine.
When to Send Wine Back
Two bad things happen to wines as they lay innocently in the cellar:
Air can seep through the cork, which will make the wine taste like either sherry or vinegar. You'll know this has happened if the wine seems like it should be poured on a salad, or if it tastes too strong, or, in the case of red wines, if it has turned slightly amber in color.
The cork can become infested with bacteria, causing the wine to take on an intensely moldy flavor. If you suspect that either of these phenomena have occurred, but aren't quite sure, as your server to take a sip. Be assured that it's not bad for to return a bottle that's around the bend. After all, that's why wines are tasted in the first place.