If you’re traveling to Mars, you’re going to have to bring a lot of essentials along — water, air, fuel, food. And, let’s be honest, you probably wouldn’t mind packing some beer too. A two-year journey — the minimum length of a Mars mission — is an awfully long time to go without one of our home planet’s signature pleasures.
Now, Anheuser-Busch InBev, the manufacturer of Budweiser, has announced that it wants to bring cosmic bar service a little closer to reality: On Dec. 4, the company plans to launch 20 barley seeds to space, aboard a SpaceX rocket making a cargo run to the International Space Station (ISS). Studying how barley — one of the basic ingredients in beer — germinates in microgravity will, the company hopes, teach scientists a lot about the practicality of building an extraterrestrial brewery.
“We want to be part of the collective dream to get to Mars,” said Budweiser vice president Ricardo Marques in an email to TIME. “While this may not be in the near future, we are starting that journey now so that when the dream of colonizing Mars becomes a reality, Budweiser will be there.”
Nice idea. But apart from inevitable issues concerning Mars rovers with designated drivers and who exactly is going to check your ID when you’re 100 million miles from home, Budweiser faces an even bigger question: Is beer brewing even possible in space? The answer: Maybe, but it wouldn’t be easy.
Start with that first step Budweiser is investigating: the business of growing the barley. In the U.S. alone, farmers harvest about 2.5 million acres of barley per year. The majority of that is used for animal feed, but about 45% of it is converted to malt, most of which is used in beer. Even the thirstiest American astronauts don’t need quite so much on tap, so start with something modest — say a 20-liter batch. That’s about 42 pints, which should get a crew of five through at least two or three Friday nights. But even that won’t be easy to make in space.
“If you want to make 20-liters of beer on Earth you’re going to need 100 to 200 square feet of land to grow the barley,” wrote Tristan Stephenson, author of The Curious Bartender series, in an email to TIME. “No doubt they would use hydroponics and probably be a bit more efficient in terms of rate of growth, but that’s a fair bit of valuable space on a space station…just for some beer.”
Still, let’s assume you’re on the station, you’ve grown the crops, and now it’s time to brew your first batch. To start with, the barley grains will have to go through the malting process, which means soaking them in water for two or three days, allowing them to germinate partway and then effectively killing them with heat. For that you need specialized equipment, which has to be carried to space and stored onboard. Every pound of orbital cargo can currently cost about $10,000, according to NASA, though competition from private industry is driving the price down. Still, shipping costs to space are never going to be cheap and it’s hard to justify any beer that winds up costing a couple hundred bucks a swallow.
The brewing process itself would present an entirely different set of problems — most involving gravity. On Earth, Stephenson says, “Brewers measure fermentation progress by assessing the ‘gravity’ (density) of the beer. The measurement is taken using a floating hydrometer. You’re not going to be doing that in space.”
The carbonation in the beer would be all wrong too, making the overall drink both unsightly and too frothy. “The bubbles won’t rise in zero-g,” says Stephenson. “Instead they’ll flocculate together into frogspawn style clumps.”
Dispersed or froggy, once the bubbles go down your gullet, they do your body no favors in space. The burp you emit after a beer on Earth seems like a bad thing, but only compared to the alternative — which happens a lot in zero-g, as gasses don’t rise, but instead find their way deeper into your digestive tract.
The type of beer you could make in space is limited and pretty much excludes Lagers — or cold-fermented beer. “Lager takes longer to make compared to most beers, because the yeast works at a lower temperature,” says Stephenson. “This is also the reason for the notable clarity of lager: longer fermentation means more yeast falls out of the solution, resulting in a clearer, cleaner looking beer. Emphasis on ‘falls’ — and stuff doesn’t fall in space.”
Finally, if Budweiser’s stated goal is to grow beer crops on Mars, they’re going about the experiment all wrong. Germinating your seeds in what is effectively the zero-g environment of the ISS is very different from germinating them on Mars, where the gravity is 40% that of Earth’s — weak by our standards, but still considerable for a growing plant. Budweiser and its partners acknowledge this possibility and argue that the very purpose of the experiment is to try to address the problem.
“Gravity as a continuum is an active area of research,” says Michael Roberts, deputy chief scientist of the Center for the Advancement of Science in Space (CASIS), which is collaborating with Budweiser on the space station study. “We do not yet know if plants or any living organisms experience a threshold effect where fractions of 1-g have the same effects as microgravity.”
That’s just one of a whole lot of known unknowns, and there’s no certainty they’ll ever be sorted out. Still, there’s no denying that an extraterrestrial brewery has appeal. Budweiser may be in the business of making and marketing beer, but it’s hard to argue with company vice president Marques when he asks, “How good will life on Mars be if you can’t enjoy a cold beer?” The answer: less good than it ought to be. If we have the wherewithal to get ourselves to Mars one day, here’s hoping we’ll also figure out a way to toast our own arrival.