Sorry, But You Might Want To Rethink Those Trendy Copper Mugs

Even if you don't follow the latest hipster alcohol trends, you've probably seen copper mugs popping up in the kitchen utensils section of your local department store. That's because the Moscow Mule — a drink made with vodka, lime juice, and ginger beer and traditionally served in a copper mug — has been having a moment.

But a recent report from the Iowa Alcoholic Beverages Division has come to ruin some of the fun. The division issued a bulletin to make those selling alcoholic beverages in copper mugs aware of the Food and Drug Administration's stance on alcohol and copper and its alloys, which essentially says that they should never mix (if the liquid has a pH below 6.0).

Acidic liquids like, you know, lime juice, can cause the outer layer of copper (and alloys like brass) to seep into your drink. Too much copper can be poisonous and cause food borne illnesses, the report says.

But there's an important line in the scary-sounding report that should keep you from running to the kitchen to throw out all of your trendy copper mugs. "Copper mugs lined on the interior with another metal, such as nickel or stainless steel, are allowed to be used and are widely available."

You see, this isn't a new study or report, and the FDA has long advised against using pure copper mugs for acidic liquids like the Moscow Mule, so many of the manufacturers making these mugs in the U.S. already know that they shouldn't be 100% pure copper and line the inside of the mug with nickel, tin, or stainless steel. And even if you do drink the occasional acidic drink from a pure copper cup, it's likely not going to cause serious damage.

"It's not that if you drink a Moscow Mule from a copper cup, you're going to die," David Werning, a spokesperson for the Iowa Department of Inspections and Appeals, told NECN. "The food code only governs licensed food establishments. I know for a fact in my own family there are some copper cups. What you want to do in your home kitchen or home bar is up to you."

So there's no need to ditch the Moscow Mule or it's signature cup — after all, they are beautiful, and keep your drink extra cold thanks to the metal. But if you're really concerned, just make sure your cup literally has a silver lining.