I got to wondering if it’s at all possible to brew beer/wine/etc… in microgravity (i.e. “weightlessness”).
Seems to me that a number of processes involved in fermentation might not work so well without up and down, or some kind of centrifuge to simulate it.
Any thoughts?
Maybe with a gas permiable membrane. The easiest solution though is probably the centerfuge.
ETA: I don’t think it would take much of a centerfuge.
Possible? I would think so. I can’t think of any reason yeast would not convert sugar to ethanol just because they’re weightless.
Challenging? Definitely. Gravity plays a roll in removing proteins, dead yeast parts, and other impurities. It also forces the CO2 waste from fermentation up and away from the yeast. Without this, the localized build-up of CO2 and other waste products would kill the yeast off pretty quickly. Not to mention how homebrew systems use gravity when moving the various stages of beer around.
Just moving your average homebrew set-up into space would not work of course, but I’m sure with some ingenuity someone could come up with a workable apparatus.
Based on my experience – I just got my fermenting kit and I’ll be starting my first batch of mead in a few days – it seems to me that the fermenting process itself would be unaffected by a microgravity or freefall environment. More of an issue would be offgassing extra carbon dioxide; my kit relies on gravity to keep the fermenting mixture away from the airlock. Racking from one fermentation vessel to another or filling bottles would be a bit different too.
I think the OP’s question is a very important one, which requires original research. Somebody please call Space Station Alpha, we have a project for them!
You want the CO2 close to the yeast, don’t you? It keeps the Oxygen away so the yeast has to digest sugar anaerobically. Thats why Earthbound brewing kits have the airlock, to keep oxygen out using the CO2 pressure.
That’s not really true… during brewing there are 2 phases, the first being aerobic, the second being anaerobic. This is why you’re supposed to oxygenate the wort by shaking vigorously before you close the airlock. During the aerobic phase the yeast is multiplying, during the anaerobic it is actually consuming the sugar. The purpose of the airlock is not to keep out oxygen. It is to provide an opening where gas can escape, but none can come back in. The reason to keep gas out is microbial contamination, not oxygen contamination.
As to the OP… yes, I think it would be possible, but it would require the use of:
1: A selectively permeable membrane that allows CO2 and O2 exchange, but not liquid exchange
2: A centrfuge for separating the lees from the wort
3: Custom designed equipment to contain and operate the above
Close. Yeast can use oxygen, and will do so until it is used up in the solution, however, this pathway does not produce ethanol. The airlock is to prevent the atmospheric oxygen from replacing the oxygen that is used up.
CO2 is a waste product of the fermentation process. Ethanol fermentation - Wikipedia
Cosmic relief is correct re. the main reason for the airlock. However, it is also there to keep oxygen out during the anaerobic phase of brewing.
The sugars are consumed during both the aerobic and anaerobic phases, it’s just the end products that differ (ethanol is only produced during the anaerobic phase, therefore the desire to keep atmospheric O2 out.)
I really think that the air lock is to prevent microbial contamination of the wort. Lambic beers are fermented in open air containers so having the wort exposed to air does not prevent the yeast from making alcohol.
I stand corrected on that, then. An airlock would be required in microgravity either way, but the simple water-trap airlock obviously would not be appropriate.
Hey, if you can mircobrew in gravity, you should be able to brew in microgravity.
After thinking on that a bit more, you’re both correct. I think I had always assumed that second reasoning for the airlock based on my knowledge of yeast metabolism. The fact that open fermentaion works, presumably without a significant decrease in alcohol production proves me wrong.
This is such an obvious experiment. It is such a potentially useful experiment. I can’t beleive they haven’t done it yet. I can’t beleive that nobody has proposed it.
Could we get a doper designed experiment in space?
http://science.nasa.gov/headlines/y2001/ast21sep_1.htm
The first google hit from the search brewing in space.
Well, CO2 is heavier than air, so if there is enough headspace then there should be a layer of CO2 right over the wort even if it is exposed. Plus, during fermentation, the foamy head (krausen) also provides a sort of barrier of CO2 foam. So it could be that it’s important to minimize exposure to oxygen, but this isn’t really the purpose of the airlock.