It’s (allegedly) Oprah’s Winfrey’s favorite cocktail and it’s also extremely popular to post on social media due to its signature copper mug. But now the Moscow Mule comes with a pretty strong warning from public health officials.
“High concentrations of copper are poisonous and have caused foodborne illness,” Iowa’s Alcoholic Beverages Division said in a statement. “When copper and copper alloy surfaces contact acidic foods, copper may be leached into the food.”
Iowa’s new regulation, which prohibits copper from coming in contact with foods and beverages with a pH below 6.0, is aligned with the U.S. Food and Drug Administration’s (FDA) most recent Model Food Code. The FDA’s recommendation says fruit juice, vinegar, and wine should not be served in purely copper containers.
The Moscow Mule contains vodka, lime juice, ginger beer, and a lime slice for garnish. The drink turned 75 last year and it’s the perfect combination of light, crisp taste and trendy presentation. A mere search for the cocktail on Instagram garners close to a half a million results.
“Spirit, ginger, lime, bubbles, those are all great things,” said mixologist Colin Shearn. “The template is foolproof.”
The copper mug, it seems, is a matter of both aesthetic and functionality. Copper helps keep the drink cold due to its thermal conductivity.
So what will happen to what may be the world’s most insta-worthy drink? Not much, it seems. Iowa’s new regulation only applies to wholly copper mugs, but many mugs used to serve Moscow Mules are lined with nickel or steel, which are perfectly fine for consumption of food and beverages with a pH below 6.0.
That’s right. Everything’s fine. Your Moscow Mule is still intact. Just check to make sure your mule mug is lined with steel and drink up.