Ever Wonder About the 'Legs' You See in a Wine Glass?

It’s something that you see wine drinkers do - swirl their wine glass and then look at the ‘legs’ that run down the inside of the glass. And, often they’ll equate the quality of the wine with the legs by saying things like “Oh!…this wine has really great legs.”

It’s a real phenomenon, that involves some chemistry and physics, but I won’t bore you with the details.

The simple explanation of the ‘legs’ in a wine glass is that it’s all about the alcohol.

The droplets that form and move down the sides of the glass after the wine is swirled are a product of the fact that alcohol (ethanol) in wine, evaporates more quickly than water. The alcohol crawls up the glass as it evaporates, but since there is a film of water on top, it is pushed up in an arch. Eventually gravity causes the water's surface tension to be broken, allowing the water to run down, in ‘tears’ that form ‘legs.’

If you really want the technical details on this effect, look up the Marangoni effect.

So, yes, a great wine can exhibit great legs inside a wine glass. But the truth is that any wine can do that. Cheers!

Why Do People Swirl Their Wine Glass?

Ever wonder why people swirl their glass of wine?  Is this just something that wine snobs do? Or is it a kind of nervous habit?  Are they doing it so they can examine the 'legs' of the wine?  Or, are they doing it just to look cool? What's the point?

Well, there are two basic reasons to swirl a glass of wine; aeration and aromas.

First, aeration.  This is simply adding air to the wine.  This seem odd at first. Why does wine need air? After all, it's been intentionally stored in an air-tight bottle for some time. Well, with most red wines (typically the younger wines), adding air helps improve the flavor of the wine. Some of the improvement is due to the fact that evaporation occurs when you swirl which releases some of the stronger, less appealing compounds in the wine. But, overall, swirling allows the wine to get exposure to air which helps improve the flavor.  The act of swirling the wine in the glass allows the wine to coat the inside of the glass, giving the wine more surface area and hence, more exposure to air.

Second, while you are swirling the wine and coating the inside of the glass, you are filling your glass with the wine's aromas - all those wonderful scents associated with the particular wine.  This allows you to sniff the wine and to fully enjoy the wine experience on your tongue and in your nose.  Both of which are very important to enjoying any flavorful food or drink.

But you don't want to swirl all wines.  Sparkling wines (or 'Champagne') should not be swirled. This will quickly release all those wonderful bubbles and lead to a less-sparkling experience.  

As to swirling a glass of wine to examine its legs (those tear drops that slide down the inside of a wine glass), it may be fun to watch, but it really doesn't tell you anything about the quality of the wine, just that it has alcohol in it.

So, go ahead and carefully swirl your wine.  Yes, it may look cool, but it is actually helping the wine and improving your experience of the wine.  Cheers!