For the uninitiated, a Moscow Mule has vodka, ginger beer, and lime, and thus is acidic, explains Live Science. "High concentrations of copper are poisonous and have caused foodborne illness". Although the copper mugs may look stunning, they aren't necessarily healthy when used to house drinks that have an acidity of a pH below 6.0.
The Moscow Mule cocktail is getting lots of buzz lately, but it's not all good news. Public health officials warned that using those mugs could have unwanted health consequences. Foods that are acidic (pH lower than 6.0) can corrode the copper and cause the metal alloys to mix in the food or liquids.
An advisory bulletin from Iowa's alcoholic beverages division notes that, in keeping with food and drug administration guidelines, copper should not come into contact with acidic foods with a PH below 6.
Symptoms of copper poisoning include abdominal pain, vomiting, diarrhea and jaundice, according to the U.S. Copper pots, for instance, can alter the flavor of the recipe. That means drinks like wine, vinegar, and fruit juices also should not be served in copper mugs either. A different interior should line the inside of the cup, such as stainless steel and nickel.
Copper poisoning, similarly to lead or other metal poisoning, occurs after a period of exposure.
"You're at more risk for alcohol consumption", Marler said.