Legs are the trails of liquid that form on the sides of a glass after swirling the contents.
It is caused by alcohol having a lower surface tension than water. Having legs can be a surprisingly controversial and widely misunderstood topic for oenophiles, whisky enthusiasts and rum drinkers – it shouldn’t be.
Legs are not an indication of quality of a spirit. As it can tell you key information about the alcohol level however (higher ABV have more legs), it is a handy visual aid for those tasting something blind and trying to decipher what’s in their glass.