So What are Wine Legs?
See those translucent “tears of wine” meandering their way down the inside of your wine glass? For me, they become more apparent the drunker I get. Wine legs actually occur because of a neat phenomena, and it has nothing to do with how “thick,” “chunky” or sediment-packed a wine is. Separately, wine legs are not an indication of quality.
What Causes Wine Legs?
The main ingredients for those sexy legs are (drumroll…) alcohol, evaporation, water and surface tension.
Tears along the inside of a wine glass are a manifestation of the Gibbs-Marangoni Effect. This effect, as it relates to wine, is the tendency for ethanol to evaporate from the wine where the surface fluid comes into contact with the inside surface of a wine glass. As the alcohol evaporates, the surface tension of the wine around the glass increases. Nature tells us that areas in liquid with a lower concentration of alcohol will yank on the surrounding fluid. The remaining fluid (primarily alcohol and water) rushes to fill the ‘void’ in an effort to lessen the tension.
This cycle will continue as long as the wine is exposed to open air. The remaining ethanol and water-wine mixture will adhere to the inside of your glass as you sip and swirl, until it collapses under its own weight. The end result of the Gibbs-Marangoni effect are those tears of wine (joy) you see around your glass.
More Alcohol in Wine = More Legs
The higher the alcohol content of a wine, the longer, fatter legs you’ll get to see. That’s because more ethanol is evaporating at any given time, causing relatively large quantities to collect, and ultimately collapse under gravity.
More Sugar in Wine = Slower Legs
While sugar content throughout fermentation determines how much alcohol a wine will ultimately have, residual sugar in wine has nothing to do with the number or size of legs you see. It does, however, slow the speed at which wine tears drop. Higher sugar content means a denser liquid, causing higher surface tension and attraction.
Watch NASA Study the Gibbs-Marangoni Effect in Space
What are your favorite wines with long legs? Let us know in the comments, we’d love to try them!