Moscow mules are essentially defined by the cute copper mugs they're served in, but a new advisory bulletin from Iowa's Alcoholic Beverages Division sheds a new light on the famous cups. The state has actually advised against serving the cocktails in these cops due to a risk of copper poisoning.
"High concentrations of copper are poisonous and have caused foodborne illness," reads the bulletin. "When copper and copper alloy surfaces contact acidic foods, copper may be leached into the food." The state follows the Food and Drug Administration's code that prohibits copper from being in direct contact with acidic foods with a pH below 6.0 (which includes Moscow Mules, wine, and vinegar).
Copper poisoning may cause liver and kidney damage over time, and if consumed directly, will cause nausea, vomiting, abdominal pain, and liver failure. But as food poisoning attorney Bill Marler told Business Insider, "it would take years to ingest a dangerous amount of copper by drink drinking Moscow Mules alone." More specifically, "If you're only drinking Moscow Mules occasionally—or even less than every day—you're probably not going to be poisoned."
In short, avoid the cups if you want to err on the side of caution, but if you're a very casual Moscow Mule drinker, serving them the way they were intended will not hurt your health.
Read the full break down over on Business Insider, and share your thoughts on the advisory below.