A friend recently confessed she doesn’t like wine with a strong aftertaste that lingers after she swallows. “I want to get on to the next sip,” she said, and asked me if that was wrong.

I explained that wines with a long “finish” (the word we use when the aftertaste is pleasant) are valued for their complexity and nuance. Most wines actually do not have a long finish — we are happy with any wine that doesn’t finish “short,” as though it vanished down our gullets without leaving a calling card. She then bragged to everyone at the dinner party that I had endorsed her cheap taste in wine.

So how do we “taste” wine? Now that I’ve encouraged you to pay more attention to the smells and flavors in the world around you, how do you recognize those flavors in your glass?

There are no rules, only guidelines. Follow these and you should gain some insight into why you like certain wines more than others. Follow them too closely, and you might offend some people.

Wine engages all our senses: Hearing, from the sound of the cork, the glug-glug of the wine leaving the bottle and the clink of glasses in a celebratory toast. Other senses are more involved.

Sight gives us several clues. A red wine that is intensely purple in color is very young; with age, it will turn to ruby, then brick red. White wines are the opposite: They usually are light colored in youth, turning golden with age. Tilt your glass and observe the “rim” where the wine touches the glass; color variation indicates age, no variation means the wine is still quite young. This is why we hold the glass by the stem rather than the bowl. Even we wine geeks, with our supposedly superior sensory powers, can’t see through our fingers.

Now swirl the glass. Thick streams of liquid flowing down the side indicate a full-bodied wine, possibly on the high end of the alcohol spectrum. These streams are called tears or legs.

You now know whether the wine is young or old, full- or light-bodied, without even tasting it.

Next, smell the wine. This is where you will find all those aromas of various fruits, spices and what-have-yous. Stick your nose in the glass and inhale deeply, engaging your sensory memory and imagination. (This is why wine glasses should be only about a third full: The aromas collect in the glass, and you really don’t want to stick your nose into the wine itself.) Fresh berries from the market, your grandfather’s leather chair, a walk in the woods after a heavy rain: They may all be here.

Take a sip. Swish the wine around your mouth, as if you’re gargling. (This is where wine tasting trips from vaguely antisocial to potentially sociopathic.) Sweetness will register on the front of your tongue, bitterness on the back. Acidity — key to wine’s structure — will tickle the sides of your tongue and leave you refreshed, yet wanting more.

Before swallowing, try to bring some air into your mouth. This “volatizes the esters” of the wine, meaning it brings out more of those unexpected aromas and flavors. It is also dangerous to do in polite company. A dear friend of mine sounds like a flushing toilet. But if you practice you can do this discreetly and appear merely contemplative.

Finally, swallow and smile, with your mouth open. As you rejoin the company of your dinner companions, notice how the wine’s flavor lingers in your mouth. This is the finish. A long finish can last for several seconds, with the flavor changing as a sign of the wine’s complexity. Savor it. Your food’s cold by now anyway.

McIntyre blogs at dmwineline.com. On Twitter: @dmwine.