Regardless of whether you’re a weekly frequenter (or drunken bro-fighter) at Center City Sips, summer imbibers should take note: One of the most summery drinks of all time, the Moscow Mule, could be potentially very harmful – even poisonous – to your immune system.



The threat of poisoning lies not within the drink’s mix of vodka, ginger beer and lime, but in the container it’s traditionally served in. Since the Moscow Mule started becoming a thing at every suburban barbecue sometime in the mid-20th century, the drink’s copper mug – used for its ability to keep drinks chilled, boost the taste and add more bubbles to the carbonated beer for optimum fizziness – has been a key part of the equation.

It may be time for lovers of the Moscow Mule to part ways with the copper mug, however, as the Alcoholic Beverages Division of Iowa announced that copper should not come into contact with acidic foods with a pH below 6.0, which the pH of the traditional Moscow Mule falls well below, the advisory bulletin said.

"The recent popularity of Moscow Mules, an alcoholic cocktail typically served in a copper mug, has led to inquiries regarding the safe use of copper mugs and this beverage," the advisory notes.



"High concentrations of copper are poisonous and have caused foodborne illness. When copper and copper alloy surfaces contact acidic foods, copper may be leached into the food."



Though most restaurateurs know not to use copper when preparing food, being barred from using it for drinks is a newer discovery.



Copper poisoning can lead to abdominal pain, diarrhea and vomiting, and longer health problems – liver failure or even death – if it’s a dire case of long-term exposure. There is a way, however, to keep drinking those Mules without losing the copper cup ambiance. As long as the mug is lined with another metal, like nickel or stainless steel, you should be OK.

Right now, the use of copper mugs is only limited in a few states, including Iowa and Wisconsin.

So, while it may be tempting, don't fall into the trap of shelling out cash for mugs that brag about being 100 percent pure copper with no nickel lining. Cheers!