It’s deep into August. The heat waves have been persistent for a couple months now. It’s been a long summer. And there’s a pretty good chance that over this sweltering summer you’ve had Moscow Mule or two. It’s hard to beat that ice-cold copper mug full of vodka, lime, and fizzy ginger beer.
You know you shouldn’t really be drinking that mule out of actual copper lined mug, right? Right??? Well, the Advisory Beverages Division of the State of Iowa is here to remind us of some salient facts.
They recently released a paper — using FDA stipulations — that notes that copper is a reactive metal (like iron, aluminum, and steel). Copper metals can leach into the contents of what they’re in contact with if those contents have a “pH below 6,” according to the FDA’s guidelines. Basically, any heavily acidic food or fluid has a pH below 6. This is why chefs don’t cook tomato sauces or anything with lemon or vinegar in copper pans or iron skillets. Generally, stainless steel is used because it’s non-reactive.
Anyway, a Moscow Mule is lime juice with ginger beer and very acidic. So, copper metals are going to leach into your cocktail. A build up of copper in your system can lead to copper metal poisoning — which causes severe diarrhea, vomiting, and all sorts of unwanted ailments. However, only trace amounts will leach into you Moscow Mule from a copper mug. Whereas the FDA and studies of copper poisoning make it clear that you need to ingest “large amounts” of copper for it to manifest as metal poisoning.