Wednesday, August 9, 2017

Moscow mules and copper toxicity

Via the Washington Post, this interesting health advisory from the Iowa Alcoholic Beverages Division:
Iowa, as well as many other states, has adopted the federal Food and Drug Administration’s Model Food Code, which prohibits copper from coming into direct contact with foods that have a pH below 6.0.Examples of foods with a pH below 6.0 include vinegar, fruit juice, or wine. 
The pH of a traditional Moscow Mule is well below 6.0. This means that copper mugs that have a copper interior may not be used with this beverage. However, copper mugs lined on the interior with another metal, such as nickel or stainless steel, are allowed to be used and are widely available.
So it seems to me that the acidity of a Moscow Mule comes from the carbonation of the ginger beer and the lime. It's reasonable to me that it's below 6 (and somewhere in the pH 3-4) range. But the question that I have is what is the threshold for copper toxicity? Thanks to a report from the Agency for Toxic Substances and Disease Registry, we have a sense:
Slightly higher thresholds for gastrointestinal symptoms were observed in two acute-duration repeated exposure studies in which subjects used a copper-containing water as their primary source of drinking water for 1 or 2 weeks (Pizarro et al. 1999, 2001). In the 2-week study, 60 women were given copper sulfate containing water to be used for drinking and cooking purposes. No significant alterations in serum biomarkers of liver damage (alanine aminotransferase, aspartate aminotransferase, γ-glutamyl transferase) were observed in the subjects at the end of the study. An increased occurrence of nausea, vomiting, and/or abdominal pain was observed when the women were exposed to 3 ppm copper as copper sulfate (0.0731 mg Cu/kg/day) (Pizarro et al. 1999); no significant increases in the incidence of gastrointestinal symptoms were noted at 1 ppm (0.0272 mg Cu/kg/day). Nausea, vomiting, and/or abdominal pain were also reported by women ingesting water containing 5 ppm (0.096 mg Cu/kg/day) as copper sulfate or copper oxide for 1 week (Pizarro et al. 2001). 
Would I be willing to bet there was less than 3 ppm copper in a Moscow Mule that had been sitting in an all-copper mug on the counter for more than an hour? Probably not.

(Aren't we done with the Moscow Mule trend? I feel like it peaked two years ago? I dunno, I'm a beer guy myself.) 

12 comments:

  1. Though at 3 ppmw, say a 60 kg person at 0.0731 mg Cu/kg/day gives 4.4 mg, so roughly 1.5 litres of ~7% ABV Moscow mule. So, 8 or 9 shots of vodka, ~1000 calories and the copper. "An increased occurrence of nausea, vomiting, and/or abdominal pain" indeed.

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  2. "(Aren't we done with the Moscow Mule trend? I feel like it peaked two years ago? I dunno, I'm a beer guy myself.)"

    Using that logic, can't someone say, "Aren't we done with the Craft Beer trend?" Seems like that peaked several years ago as well. Why do you care if the "trend" is continuing or not - unless you drink a lot of Moscow (or Kentucky or Texas) Mules and you want the "trend" to end so the prices go down.

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    1. I think that focusing on a single drink means that bars and stores tend to deemphasize other drinks - if every new restaurant opening is a wing place, then there's probably lots of other types of restaurants that are going away. Craft beers are likely to be more diverse, so the expansion of the trend makes more types of beers available, rather than fewer. People are always going to want to be hip, and you have to live with that mostly.

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    2. Not the best analogy unless bars are opening that only sell Moscow Mules. Bars don't emphasize a drink, except to run specials. Not like bartenders forget how to make other drinks, or they stop stocking other liquors. Craft beers "may" be more diverse (although many tend to brew the same type (over-hopped IPA's), but it's still "trendy" and to re-use a Seinfeld line, "hipster doofus" to emphasize "craft beers"). What is that anyway since many of the so-called "craft breweries" are being purchased by the big breweries. How many different glasses does a bar need to stock in order to serve the beer at the optimal drinking experience? Note: I'm a beer drinker and home brewer so I am on the beer side.

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    3. My pseudo-joke about the trend was really about the relative commonality/rarity of folks drinking Moscow Mules. Around these parts, it seemed like there were a raft of news stories about the mugs being stolen, etc.

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    4. I begrudge the thought that craft beer is a "trend" that will someday pass. Before the surge of craft beer, we had a limited number of options for mass produced foamy lagers. Heineken, Budweiser, PBR... I wouldn't even stomach that nowadays. Now the bigger brewing companies are forced to innovate and actually focus on flavor and quality in order to compete with the wealth of competition independent breweries present, simply because they offer a variety of delicious options. There's nothing pretentious or hipster about desiring craft beer.

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    5. I think the mugs get stolen because good ones are ~$30 a pop; so it's not terribly surprising.

      There is nothing pretentious or hipster (although there are quite a lot of pretentious hipsters that like to wax poetic about "craft" beer) about wanting good, flavorful beer. It's the over-abundant use of "craft" or "artisanal" that is overplayed. Good quality beer doesn't need to be "crafted" - most of the original independent breweries are no longer "craft" (Sierra Nevada, etc.). Large breweries are more than capable of brewing these same beers (and will probably do it better because of potentially having stricter controls on the brewing process, and cheaper due to leverage of buying power) and that won't make the brews any less flavorful and enjoyable. But, they can sell a lot of "mass produced foamy lagers" (which have their place in my fridge as well). As a home brewer ("craft" or "artisanal") it can be quite difficult to produce the same beer as the large breweries; however, I can match the taste of almost any small batch brewery.

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    6. Same Anon as above - should have said "As a home brewer (NOT "craft" or "artisanal")... as those words have been co-opted by every hipster at the Farmers Market. And to say the big breweries don't focus on quality is flat out wrong. They produce a quality product for their market. When one says they don't focus on quality it's like they are throwing out every other batch because it's crap. Far from the truth, their quality processes are exceptional, they just don't brew the types of beer you like - that's cool.

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    7. It was my understanding people reached for big brewery beers for their low prices, rather than an actual preference for those flavors, or lack thereof, and the requisite headache they seem to deliver. Much like my disagreement of people watching The Big Bang Theory or listening to Justin Bieber, I have always had a difficult time letting people go through life with terrible tastes, and simply recognize that these are subjective matters and everyone is entitled to an opinion. However I refuse to believe that big brewers are genuinely crafting what they believe is a beer with superior quality and flavor to most small batch beer now on the market - rather, they are engineering the cheapest alcohol that people are willing to stomach. Key words being "their market", I guess.

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    8. Anon 7:02 PM here, you may apply as many beer snob stereotypes to me as you please, I deserve it.

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  3. As a huge beer loser/snob, I can say I was never aware of a moscow mule trend in the first place, thankfully.

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  4. This seems like the kind of thing a beer snob might appreciate:

    http://lewisandquark.tumblr.com/post/163753995072/craft-beer-names-invented-by-neural-network

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