you're sitting across from your boss (who fancies himself a bit of a wine geek) at dinner. the sommelier presents the bottle, then asks if he'd like it decanted. your boss replies with an ardent affirmative, and the sommelier carefully pours the entire bottle into a decanter.
once transferred to its new vessel, the sommelier then pours a small bit of the newly decanted wine into your boss's enormous wineglass. he looks at it for a moment, then begins swirling it furiously in his glass. then, he sticks his schnoz in and inhales deeply.
he smiles, nods at the sommelier, and takes a taste.
what the hell is he doing!? what's with the decanting? and the swirling? is your boss just putting on airs and making a huge show out of nothing at all?
actually, no. there is a very good reason for the decanting, swirling and sniffing. and you should be doing it, as well.
there are two main reasons why one would decant a bottle of wine. the first, and most obvious, is to pour the wine in the bottle off of any sediment that might be collected at the bottom. if a wine is older, or if a wine has been made without filtering (many organic wines are unfiltered), then there may be some sediment at the bottom of the bottle that you don't want in your mouth. it won't hurt you, but it's pretty nasty. the best way to go about this is to have a light, like a candle or even a flashlight, illuminate the neck of the bottle as you slowly pour it into the decanter. you'll see the sediment creep up, and once it reaches the neck?ta da! stop pouring.
the second, and less obvious, reason for decanting a wine is if it needs to "open up." the short explanation of letting a wine "open up" is that oxygen creates a chemical reaction with wine. when exposed to oxygen, the wine begins to age faster. this may be bad, unless you are consuming a wine that is incredibly tannic. in that case you may want to speed up the aging process. this will soften the tannin, thereby making it lusher, fruitier and ultimately, more immediately drinkable.
what you are doing in your glass while you are swirling it is basically a miniature version of the decanter. you are swishing the wine to and fro (being careful to keep at least most of it in your glass), introducing oxygen into the mix and letting the wine "relax" and open up even more.
swirling it around also throws the aroma up and out of the wine. the reason expensive wine glasses enormous and cathedral-like is because all that empty space is meant to capture the aroma of the wine that is being thrown off, and to keep it right there.
we all learned in 4th grade that half of our sense of taste is smell. that's why you can't taste anything when you're stuffed up with a cold. so, it stands to reason that the better you can smell something, the better you'll be able to taste it. designing a glass that can capture that intense aroma is the optimal way to also taste the wine. if designed properly, your nose should fit perfectly inside the glass as you sip the wine, allowing both senses committed to the tasting of vino the ability to do their jobs well.
so, the next time those excel spreadsheets are late for that friday board meeting, or your power point presentation isn't ready for the conference in cleveland, distract your boss with a little vino shop talk. before you know it, he'll be pouring you a glass of something from his cellar, and you'll be staring out the window of your new corner office.