(KMSP) - Public health officials are warning that the copper mugs used to serve the popular Moscow mule cocktail could be poisoning you.
An advisory bulletin issued by the Iowa Alcoholic Beverages Division says copper should not come in in direct contact with food or drinks that have a pH below 6. The pH of a traditional Moscow mule, made with lime juice, ginger beer and vodka, is well below 6.
According to the United States Food and Drug Administration, high concentrations of copper are poisonous and can cause foodborne illness if the copper it comes into contact with acidic foods.
In Iowa and other states that have adopted the FDA's food code, copper mugs that have a copper interior are not allowed to be used to serve Moscow mules. Copper mugs lined with another metal, such as nickel or stainless steel, however, are fine to use.