That Wine’s Got Legs! What droplets tell you about your wine (and what they don’t)

No, we don’t mean it’s going to crawl away on you.

The next time you spot someone swirling their glass, then staring deeply into it, they’re doing one of three things:

1. They’re trying to look smart by going through some motions they saw in a movie
2. They’ve had too much wine and you should be a good pal and offer them a ride home
3. They actually know what they’re doing and they’re looking for “legs”

In September, we mentioned legs when we told you how to taste wine like a pro. But there’s a lot more to understanding what they are, what causes them and, probably most important, what they tell you about the wine you’re about to enjoy. There’s a lot of science behind it, so buckle up. We’re going for a ride.

What are wine legs?

In short, wine legs are the droplets that form and run down the inside of the glass after you swirl or tip for a sip. The streaks resemble legs, or maybe more like tentacles or tears. In fact, they have many different names, including tears, fingers or (if you want to really impress your friends) the Gibbs-Marangoni effect.

What causes wine legs?

Here’s why the term “legs” might be most appropriate. They form after your wine actually creeps up the walls of the glass.

The alcohol – technically ethanol – in wine evaporates faster than the water content, and as the thin layer of wine evaporates from the walls of your just-swirled glass, it increases surface tension. The higher-tension wine on the walls draws up the low-tension stuff down below.

This process can happen quickly before your eyes, and it looks kind of magical. A warmer environment – like when you hold the glass in your palms – will speed up the reaction.

Once enough wine collects on the glass walls, it forms droplets that tumble back down the walls creating streaks.

OK, OK. Maybe that’s a little too sciency. You came here for a simple explanation.

Here’s the one-liner the next time you find yourself among the uninformed:

Your wine grows legs when the alcohol evaporates and the water in your wine rushes upward to replace it, then slides back down.

Ehh. That still might cause some eyes to glaze over. But it’s not your fault for having done your research.

Do thick legs mean better wine?

There’s plenty of information, even scientific studies, out there about why this happens and what it means. But the next time you hear someone brag about discovering this “terrific wine with great legs,” you can confidently, gently correct them.

Legs don’t tell you anything about a wine’s quality.

Thicker legs, however, tell you if you have a bottle that’s higher in alcohol content. With practice, and a lot of wine, you can develop your own sense for judging whether a bottle is appropriately labeled for alcohol content.

Since higher sugar content increases wine’s viscosity, thicker, slower legs also tell you that it has more sugar.

That doesn’t necessarily mean wine will be sweeter, but for some people prone to wine headaches – which are triggered by alcohol and sugar content – thick legs could mean you’re in for a doozy.

So now you have a basic understanding of what causes to grow legs. You can read about it all day, but, in our opinion, learning comes by doing. So grab your favorite glassware, a few friends and uncork a bottle together in the name of science.