Or you could just … not? Instead of messing around with fruit substrates and yeast, Sheehan and Constantine realized, all they really needed was a CO2 source—that could be hydrogen refining, the production of the antifreeze ingredient ethylene glycol, the production of plastic. Or even (and this was pretty slick) the waste CO2 from other alcohol producers. “Why try to fight thermodynamics and pull it out of the air at 400 parts per million?” Sheehan says.
Run that CO2 and some tap water through a new version of the electrolyzer and you get booze. Well, a solution of water and 20 to 25 percent ethanol, to be precise. To get it up to spirit-potency, that goes into a still. “We distill it all the way to 96 percent,” Sheehan says. That’s called the azeotropic limit, the highest percentage of alcohol-in-water a still can manage. Sheehan adds tasty water from upstate back in, to dilute it back to a typical 80 proof.
The US government defines vodka by regulation as “neutral spirits so distilled, or so treated after distillation with charcoal or other materials, as to be without distinctive character, aroma, taste, or color.” But that, of course, is nonsense. Ethanol itself has a taste, both bitter and sweet. But all the vodka you’ve ever tasted started by fermenting a sugar source—potatoes, goes the cliche, but usually these days some kind of grain.
So is Sheehan’s juice vodka? Shyeah. But not as we know it. It’s literally made from thin air.
“We have a power purchase agreement where we’re powered by renewable energy, and we have solar panels on top of the distillery, too,” Sheehan says. That’s what runs the electric boilers that heat the bottom of the still. Air has partnered with a gas provider to deliver CO2, and according to that company’s life cycle analysis it only takes 200 kg of CO2 to deliver a metric ton of same. The company factored in a ten-year lifespan for the mostly steel still, and even bought offsets for the label printing. By Air’s math, the process of making a kilogram of ethanol actually removes 1.47 kg of CO2 from the atmosphere. Since the 750 ml bottle you might buy (for $65) has 0.236 kg of ethanol in it, that’s about ¾ of a pound.
Me, a booze nerd: Carbon-negative vodka!
You, a sophisticated connoisseur: Earth shmurth! How does it taste?
I ran a small, informal tasting in the WIRED office and found Air’s vodka to be sweet and slightly viscous, even at room temperature, with a sharp, almost isopropyl-like aroma. My colleagues used words like “medicinal” and “syrupy” to describe it. One also said that if it had botanicals in it and was a gin, she would like it.
Sheehan isn’t sure why folks taste sweetness, but he does a lot of analysis on his vodka before it gets into a bottle, and he has a hypothesis. “When you’re building ethanol from CO2, you’re sticking two carbon dioxides together rather than breaking down a six-carbon sugar,” Sheehan says. That leads to a couple of unusual (safe! Perfectly safe! He hastens to say) carbon-based compounds that might account for the mouthfeel.
At least a few professionals are more psyched than my deskmates. An Air spokesperson says it’ll be available at a half dozen high end New York restaurants and bars, and a couple of retail outlets. “I had the same feeling with this that I had when I first tried St. Germain [a popular elderflower liqueur], where I was like, I just think it’s going to work.” says Eddy Buckingham, co-owner of the Manhattan restaurant Chinese Tuxedo. “It’s a great product, and the backstory legitimizes the price point.” (Gramercy Tavern is still in the evaluation stage, a spokesperson tells me.)