Over the past few weeks there have been many media reports surrounding the safety of serving Moscow Mule drinks in Solid Copper Moscow Mule Mugs. The media frenzy was just that, a data sound byte exaggerated and spread across the internet with no regard or basis in fact.
On July 28, 2017 the Alcoholic Beverages Division of the State of Iowa issued an Advisory Bulletin1 regarding the use of copper mugs for serving Moscow Mules. It advised that, per the FDA’s Model Food Code, foods with a pH below 6.0 should not come into direct contact with copper. As a typical Moscow Mule has a pH below 6, the Iowa ABD advised that Moscow Mules should not be served in unlined copper mugs. A few things to note about the Iowa ABD Advisory:
· We disagree with the State of Iowa ABD’s reasoning and do not believe there is any hazard associated with the use of unlined solid copper mugs. To our knowledge the Iowa ADB advisory has not done any testing of copper mugs, but is simply relying upon FDA Food Code Sec. 4-101.142. The Food Code is not law nor even regulation but merely a “model”.
· The Iowa Advisory applies only to UNLINED solid copper mugs (mugs with a copper interior surface). Please check if this advisory actually applies to your mug(s). Most Old Dutch Copper Moscow Mule mugs sold are LINED with either nickel or stainless steel. If the interior of your mug(s) is silver-colored your mug(s) are nickel or stainless steel lined and this Advisory does not apply. The advisory applies only to unlined solid copper mugs (mugs with a copper interior surface).
· The advisory applies only to restaurants, bars and other commercial establishments. It does not apply to home use of copper mugs and it does not apply outside of Iowa. There are many regulations that apply to restaurants and other commercial establishments that do not apply to home use.
Internet searches resulted in a number of articles anecdotally stating that they doubted anyone could be harmed by Moscow Mules drunk from an unlined copper mug3, but were unable to find any facts to validate the claim. To settle the issue we devised a test protocol to provide actual, factual data. Based on our standard recipe, we prepared two Moscow Mules in our #429 16 Oz. Unlined Solid Copper Moscow Mule Mugs as follows:
1) 180g of commercially purchased ice cubes were placed into each mug (filling the mugs approx. halfway)
2) 2 fl. oz. (59.15 ml) of SMIRNOFF® No. 21 Vodka were added to each mug
3) 2 tablespoons (29.6ml) of fresh lime juice was added to each mug
4) 9 fl. oz. (266 ml) of Reed’s Extra Ginger Brew was added to each mug
The drinks were stirred to combine, and then let sit at room temperature (73° F); one for 30 minutes, the other for 60 minutes. We removed any residual ice from the drinks, poured the remaining liquids into glass bottles and sent the samplesoff to a certified laboratory for testing. The lab reported the results to us as Milligrams per Liter (mg/L) of copper, which we converted to find how many mg’s of copper were in each 15¾ oz. drink. The results:
-The drink left for 30 minutes contained 1.82 mg/L copper, or < 0.85mg copper per 15¾ oz. drink.A
-The drink left for 60 minutes contained 1.94 mg/L copper, or < 0.91mg of copper per 15¾ oz. drink.B
What do those levels of copper mean? Well, copper consumption is actually required for good human health and the FDA Daily Value (DV) of Copper for adults is 2mg4; many daily multivitamins contain 1.5mg – 2mg of copper. Copper toxicity is quite rare, and the Tolerable Upper Intake Level (UL) for adults is considered to be 10mg/day (10,000 µg/day)5.
In other words, if you drank TWO Moscow Mules you’d still be below the FDA adult Daily Value (DV).
You’d have to drink more than TEN Moscow Mules to exceed the Tolerable Upper Intake Level (UL) for adults of 10mg/day of copper. Ten mugs would be close to FIVE QUARTS of Moscow Mules and contain 20 oz. of vodka – that’s a lot of Mules!
In conclusion, we feel the data shows it’s perfectly safe to serve Moscow Mules in Old Dutch Unlined Solid Copper mugs- just don’t drink more than ten of them a day!
If questions still remain, please contact ODI Customer Service: CustomerService@olddutchco.com
Laboratory Reports - Conducted by EMSL Analytical, Inc. for Old Dutch International