[Richard]

No, I'm not talking about extremely weak beer, I am talking about brewing in outer space. Budweiser has announced that they want to be the first beer on Mars, and they are sending some barley to the International Space Station as the next step (http://www.anheuser-busch.com/newsroom/2017/11/budweiser-takes-next-step-to-be-the-first-beer-on-mars.html )

The articles I have seen have focused on the problems of growing barley and hops, but not on the challenges of brewing beer. Mars itself has a gravity about 1/3 that of Earth, so brewing there might be similar to the way we do it, but on a space station or ship with essentially zero gravity, there would be a number of issues. Here are a few I thought of. What else?

You wouldn't be able to lauter in any normal way because you have no gravity to help separate wort from grains.

Boiling would be odd, with bubbles just sitting in the middle of the liquid without anything to make them rise.


Break material and hops would not settle out in the kettle.


You would not have krausen rising or CO2 venting off the surface during fermentation


Yeast would clump together but would not fall to the bottom of the fermenter on their own.


Pouring a glass and drinking it would be a different experience because the bubbles would not rise and create foam on the surface. You would just get a glass with all the carbonation still in the liquid. Astronaut's sinus passages tend to clog in the absence of gravity, so the  carbonation would behave differently and would not carry flavors up into your nose. The beer would be lacking in taste (but it's Budweiser anyway, so you might not be able to tell).

Most of these challenges could probably be met with some combination of centrifugal force, liquid and gas pumps and filters, but it would be pretty complicated. How do you take a sample from a spinning fermenter?

Any other issues or challenges? Any brilliant ideas on how to conquer these?

[dbeechum]

Mentioned this on facebook last week when this first was announced, but Sapporo already did a barley exposure test about a decade ago and made a space beer out of it, so... whatever.

[Richard]

Sapporo flew a few seeds into space, then grew barley on Earth from them and brewed beer on Earth from the barley. That is completely different than brewing beer in space.

[Stevie]

Most everything would be under pressure.  It would need to be mechanical pressure like a bladder squeezing.

[Philbrew]

Arthur C. Clarke, 2001 A Space Odyssey.  Do everything in a centrifugal artificial gravity.

I'm sorry, I can't do that Dave.

[Wilbur]

Diacetyl won't vaporize off per normal brewing practices, it costs $10k/lb to ship something to space so it'll all be session ales anyway. There's not an atmosphere to vent heat off, so even though it's super cold, it'll be hard to lager. Computers will attempt to murder you....

[kramerog]

Might need to improve carbon dioxide scrubbers so as not to kill astronauts during fermentation.

[Robert]

Back in the 70s brewers experimented with "continuous fermentation" as a way of maximizing plant productivity.   The idea was to have a continuous flow of wort passing through a "reactor" containing a mass of very active yeast held between porous barriers.  It never caught on, but I can imagine it might just be the way to go in zero g.

[Stevie]

Back in the 70s brewers experimented with "continuous fermentation" as a way of maximizing plant productivity.   The idea was to have a continuous flow of wort passing through a "reactor" containing a mass of very active yeast held between porous barriers.  It never caught on, but I can imagine it might just be the way to go in zero g.

Used today in yeast production.

[Richard]

I can see Homer Simpson lying down at the end of the line with his mouth open and a steady stream of beer pouring in...

[santoch]

Milling would be a big problem, if there's no gravity to force grain down into the rollers.

Grist collection and grain dust in general would be a big problem and pose a sanitation issue.