What Are Wine Legs?

What wine legs can (and can't) tell you about a glass of wine

Wine swirled in glass

There's an adage that some wine drinkers adhere to. It's not uncommon to see a seasoned wine drinker swirl their glass, let it sit, and watch how slowly the droplets form and run down the inside of the glass.

Wine legs are a complex set of interactions between alcohol, water, air, and the insides of a wine glass. The liquids separate on a microscopic level inside due to different surface tension levels for each component. This separation creates an effect that looks like tears inside a glass of wine.

This interaction is formally called the Gibbs-Marangoni Effect and is most easily observed in bottles of wine with high alcohol content.


Sign up for the Club Today

Join Firstleaf to taste delicious wines from all over the world and learn more about these grapes. The club has featured amazing examples, take the quiz to get the pairings for your individual palate.

Take The Quiz Today

IN THIS ARTICLE:

The History of Wine Legs

The process has been scientifically classified for over 150 years, but it's possible that human beings have observed it for much longer. Some even claim that the Bible references the effect: "Look not thou upon the wine when it is red, when it giveth his color in the cup, when it moveth itself aright", (Proverbs 23:31). 

In the 1850s James Thompson, brother of Lord Kelvin, observed the effect, but the theory wasn't popularized until the 1870s when Italian scientist Carlo Marangoni published his own scientific paper.

The Science of Wine Legs

What is now called the Gibbs-Marangoni Effect is all about the way that liquid flows because of surface tension gradients. 

First, what is surface tension? Have you ever seen a raindrop on a leaf that stays together instead of breaking into smaller droplets? That's surface tension. Water molecules are more attracted to one another than they are to the air (or alcohol) molecules around them. This allows the water to bunch up, essentially as if a thin film surrounded the droplets. It's the same reason that droplets combine to make bigger droplets.

In wine, something a little different happens. Wine is made of mostly water and alcohol, but the alcohol has a much lower surface tension level than water. So the water and alcohol begin to separate on a microscopic level inside of a wine glass. The alcohol moves towards the sides of the glass, and, eventually, the alcohol will climb the inside of the glass and show what we know as the legs of a wine. 

This effect is essentially the alcohol molecules piling together around the water molecules. As it climbs, the alcohol starts to evaporate which increases the incidence of the effect. Alcohol will keep climbing, evaporating, and then falling back down the side of the glass until it is gone or the glass is covered. It needs exposure to evaporate. This is why you've never seen it happening on the inside of a bottle of wine. 

This effect is most easily observed when the level of alcohol in a wine is over 12%. Think about watching it when you open your next Cabernet, the alcohol levels in Cabernet are typically higher than, say, a Pinot Noir. Your best bet will be to look for high alcohol wines by studying the back wine label. Legally, consumers need to know how much alcohol is in a bottle of wine, and the alcohol concentration will always be listed by a.b.v. (alcohol by volume).

Sweetness and Wine Legs

For most wines, the sweetness will have nothing to do with the viscosity or the wine tears. Sweeter wines can be more viscous than dry wines, but the sugar content needed to be visually observed is very large. Even most "sweeter" dry wines do not have the required 30 g/L of glycerol needed to show this effect. 

Home > Resources > what are wine legs

IN THIS ARTICLE




FEATURED ARTICLES

Petit Verdot
Chianti (Sangiovese)
Sparkling Wine
Sauvignon Blanc
Sauternes
Riesling

Sign up for the Club Today

Join Firstleaf to taste delicious wines from all over the world and learn more about these grapes. The club has featured amazing examples, take the quiz to get the pairings for your individual palate.

Take The Quiz Today