Copper Mug
12-16 ozSolid copper or copper-plated mug that stays ice-cold to the touch, iconic for mules.
History
Origin
The copper mug became iconic through the Moscow Mule cocktail, which was invented in 1941 at the Chatham Hotel bar in New York City. The story involves three businessmen with unsold inventory: John G. Martin had recently bought the Smirnoff vodka brand (then unknown in America), Jack Morgan owned the Cock 'n' Bull pub and had excess ginger beer, and Sophie Berezinski had inherited 2,000 copper mugs from her father's copper factory. They combined all three — vodka, ginger beer, and copper mugs — into a marketing campaign.
Evolution
The Moscow Mule and its copper mug helped introduce vodka to American drinkers — before 1941, vodka was virtually unknown in the US. The mug became specifically associated with mule variations (Kentucky Mule with bourbon, Mexican Mule with tequila, etc.). In 2017, Iowa's Alcoholic Beverages Division warned that unlined copper mugs could leach copper into acidic drinks, briefly causing a health scare. Most modern copper mugs are now lined with stainless steel or nickel.
Why This Shape
Copper is the most thermally conductive common metal (401 W/m-K, versus 16 for stainless steel). When filled with ice, the copper instantly conducts the cold to the exterior, creating a frost layer on the outside that is both visually striking and functional — the mug feels ice-cold to the touch, enhancing the sensory experience. The handle prevents the hand from warming the mug. For ginger beer's fizzy, spicy character, the cold metal amplifies the sharp bite.
Fun Fact
Martin, Morgan, and Berezinski promoted the Moscow Mule by traveling to bars across America with a Polaroid camera (then a brand-new technology). They'd photograph each bartender holding two copper mugs, give one photo to the bartender and keep one for the next bar: "Look, this bar is already serving Moscow Mules." It was one of the first viral marketing campaigns in cocktail history.
Best For
Substitutes
Bartender's Tip
The copper conducts cold from the ice to the exterior — that frost on the outside is the whole point. Lined copper (tin or stainless) is food-safe; unlined is technically not, but most bars use it anyway.