Since Moscow Mules first appeared in the 1940s, copper mugs have been essential for proper presentation. There are clear indications that using copper mugs for Moscow Mules enhance the individual flavors of the ginger beer, vodka, and lime. Experts say that when vodka touches the walls of the mug, the copper begins to oxidize, slightly boosting the aroma, and enhancing the taste of the vodka. Cold copper also has a tendency to increase the amount of bubbles in the carbonated ginger beer, bringing maximum fizziness to the Moscow Mule, when compared to being served in a plastic or glass container. The lime juice is also brought to life by the extra-cold copper, heightening the tangy citrus notes and reducing the acidity to better compliment the spicy ginger beer. When these three flavors reach their maximum potential, they work together to prove that the Moscow Mule deserves its home among classic American cocktails.