[thedoc]

Can you brew beer in zero gravity?

In 0G, terms like top fermented and bottom fermented cannot exist. What happens instead? Core/surface fermentation? Or will the yeast be heterogenously distributed throughout the brew? If the latter, is that likely to be similar to bottom fermentation in that most of the yeast would not be in contact with air?

Curiously yours,

Björn
Asked by Björn Fahller


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[thedoc]

We answered this question on the show...



We put this question to Professor Charlie Boone, from Toronto University...

Charlie -   I have, in fact, sent yeast into space.  Our group collaborated with NASA and we sent yeast up in the last shuttle mission.  I can guarantee that they grow perfectly well in space.
We never tried to make beer in space, but I would wager that you could make beautiful beer in space.  If you take yeast and you mix it up in a broth with glucose, they're going to love eating that glucose, and they're going to turn it into ethanol, just like they would down here on Earth.  There would be a little bit of an issue where they wouldn’t settle out of the beer.  The gas would be mixing around and you would have to vent off the gas as the yeast grew, and in the end, you'd have a very cloudy beer.  That's what I would wager.

We also put this to Dr Barbara Dunn from Stanford University...

Barbara -   As a yeast researcher and also as an amateur beer maker, I would say that if everything was done at the correct temperature, the yeast would grow fine and in zero gravity, produce a beer.  They would make the usual alcohol content and most of the usual flavours.  If you're making a really big batch of beer, you'd actually have to worry about all the carbon dioxide that the yeast make during fermentation and make sure that it doesn’t asphyxiate the astronauts. 
Finally, after the fermentation is over, I think it would be nearly impossible to bottle the beer.  I think everything would go everywhere.  So overall, I’d say that it probably wouldn’t be the best tasting beer or the best looking beer, but it would be out of this world beer.

[Geezer]

I don't think Homer will sign up to become an astronaut.