“Wine legs” is a term used to describe the droplets that are formed on the side of the glass when you are swirling the wine. Many people think how the appearance of these droplets reflects the quality of the wine. Despite what you may have heard, wine legs are actually a scientific phenomenon that can be used as an indicator about the alcohol or sugar content in wine.
Wine legs or droplets are formed due to fluid surface tension force caused by the evaporation of the alcohol in the wine. Ethanol in wine evaporates along the sides of a glass because it has a smaller surface tension than water. This means that a higher level of alcohol in the wine will result in slower and thicker droplets.
Besides alcohol, sugar can also impact the speed of the droplets. Sweeter wines are more viscous, so the droplets tend to flow slowly.
So, the more “legs” wine has- the more alcohol and sugar it contains. But, alcohol and humidity in a room can greatly affect the rate which droplets form. This means that they aren’t a straightforward indicator of alcohol and sugar content. After all, you don’t need the wine legs to tell you about the alcohol content in your wine.
