A copper mug is a mug made from, you guessed it, copper. It's most commonly associated with Moscow Mules - a refreshing cocktail made with vodka, ginger beer, and lime. While the copper mug is not necessary for making a Moscow Mule (any old cup will do), it does add a touch of class - not to mention keeping your drink cold longer.
Cocktails often served in a copper mug are:
- Moscow Mule
- London Mule
- Dark & Stormy
- Cuba Libre
- Many other Moscow Mule variants