It's a trend widely noted in the last half-decade at craft cocktail bars and otherwise regular bars that have tried to spruce themselves up with cocktail menus and bourbon flights and the like: the proliferation of copper mugs for Moscow Mules. But now a state health agency is calling into question whether they might be poisoning people, based on FDA guidelines on the use of copper vessels for serving food.
Once mostly just an old-timey gesture at Southern California bars like the now long-gone Cock 'n' Bull on LA's Sunset Strip where legend has it the cocktail was invented and Starlite in San Diego, copper mugs are now found all over the country as vessels for mules (both the Moscow and Kentucky varieties, and some others). But the Iowa state Alcoholic Beverages Division issued an advisory last week noting that the FDA's Model Food Code specifically prohibits copper or copper alloys from coming into contact with foods with a pH below 6.0, i.e. anything with fruit juice in it like the lime juice found in a Moscow Mule. Acidic liquids like vinegar, wine, or cocktails with fruit juice can cause copper in unlined mugs to leach into a drink, potentially leading to copper poisoning.
While there have not been widespread reports of such poisoning which San Francisco's CBS 5 reports can cause stomach pains, diarrhea, vomiting, and yellowing of the skin the advisory calls to question how many bars around the country have been serving the drinks in mugs made only of copper or copper alloy, without a lining made of something like stainless steel or nickel, which are harmless. Also, how has no one noted this part of the FDA code before with all the copper mugs everywhere?
The story goes that the Moscow Mule was dreamed up by a liquor distributor and a bar owner at the Cock 'n' Bull in the 1940's the former, John Martin, owned Smirnoff Vodka and was having trouble selling it to American consumers, and the latter, Jack Morgan, had been making his own ginger beer as a side project and was having trouble selling it. Copper.org includes part of the legend that there was a third person involved, a woman with a stash of copper mugs she couldn't sell, and the drink came together with lime juice and their inspiration, made all the better because copper vessels help keep drinks cold.
The drink gave birth to a whole ad campaign by Smirnoff in the 1950s and 60s, including this ad featuring Woody Allen, helping popularize Russian vodka to gin-drinking Americans by way of the Moscow Mule.
Fast-forward to the late 2000s, when the craft cocktail craze began reviving all things vintage, and the explosion in popularity of ginger beer in bars over the last six or seven years with Eater calling this "the golden age of American ginger beer" in 2015. Now copper mugs are available for cheap in every hipster housewares store.
I should note that the more expensive varieties of the mugs, like this $40 set on Amazon, tout the fact that they're made of "pure copper" and are "unlined."
The more you know...