Why Are Moscow Mules Served in Copper Mugs?

If you've ever enjoyed a Moscow mule or scrolled through Instagram, you've likely seen this popular cocktail served in a classic copper mug. But have you ever wondered why this drink is so closely tied to that specific vessel? We've done the digging so you don't have to.

What Exactly Is a Moscow Mule?

A Moscow mule is a well-loved cocktail made with vodka, ginger beer, lime juice, and sometimes garnished with fresh mint. Despite its strong Russian ties, this drink is actually American in origin. Variations of the classic recipe include the Kentucky mule (using bourbon) and the Mexican mule (with tequila).

Recipe: Moscow Mule

The Origins of the Moscow Mule

Legend has it that the Moscow mule was born from a serendipitous meeting between three or four (depending on the storyteller) struggling entrepreneurs. While the details are a bit hazy, key elements of the tale remain consistent across all versions we found:

By 1941, their gamble was no longer paying off.

Around the same time, Martin's friend found himself facing a similar predicament. Jack Morgan, the owner of the Cock 'n' Bull bar in Los Angeles, had taken a gamble by launching his own brand of ginger beer. Unfortunately, he and his bartender, Wes Price, were struggling to sell the product.

One day, as the three men were commiserating over drinks, Sophie Berezinski entered the Cock 'n' Bull with her own tale of hardship: As the daughter of a copper manufacturer in Russia, she had recently immigrated to the United States with 2,000 solid copper mugs. She hoped to sell them once settled, but success was elusive.

The group swapped their stories of misfortune, and, as if by magic, an idea struck them. The rest, as they say, is history.

There are other versions of the story, of course. In one, Sophie Berezinski is replaced by Osalene Schmitt, Morgan's girlfriend, who had inherited a business that produced copper goods.

One thing remains clear: The copper mug is crucial to the traditional Moscow mule experience.

Why Is the Moscow Mule Served in a Copper Mug?

Moscow mule enthusiasts know that tradition isn’t the only reason the drink is served in a copper mug: The metal helps maintain the cool temperature of the ginger beer, keeping the cocktail chilled and crisp.

Some experts believe the copper mug enhances the flavors of the ginger beer, vodka, and lime. When the vodka comes into contact with the copper, they claim it begins to oxidize, which subtly intensifies the aroma and elevates the vodka’s flavor.

Are Copper Mugs Safe to Use?

In 2017, Iowa's Alcoholic Beverages Division issued a warning that, in accordance with Food and Drug Administration guidelines, copper should not be used with acidic foods that have a pH below 6—this includes substances like vinegar, fruit juice, and wine.

The pH level of a Moscow mule is "well below 6.0," according to the IABD.

The notice states, "When copper or copper alloy surfaces come into contact with acidic foods, copper may leach into the food."

Copper poisoning symptoms include abdominal pain, diarrhea, vomiting, and jaundice, according to the National Institutes of Health. While acute copper poisoning is rare, NIH warns that long-term exposure to high levels of copper can lead to serious health issues, including liver failure and death.

Should you discard all your copper mugs just to be on the safe side? Probably not.

Although the 2017 press release sparked some concern, most experts agree that there’s likely no real cause for alarm.

"I consider the press release to be a case of chemophobic fear-mongering," said Trisha Andrew, assistant professor of chemistry and chemical engineering at UMass Amherst, in an interview with HuffPost.

Andrew explained to HuffPost, "Whenever liquid contacts a surface, there’s always a chance that the container will dissolve slightly into the liquid. With glass, the rate is so slow you’ll never notice it in a lifetime."

So, while it's not advisable to exclusively eat or drink from copper vessels, enjoying an occasional Moscow mule is unlikely to cause harm.

How to Prepare a Moscow Mule

Making a classic Moscow mule is simple — just mix vodka, ginger beer, and lime juice in a mug (or a glass, if you're concerned about copper exposure).