I love kimchi and I love space exploration, so I was doing some research about whether and how fermented foods such as kimchi might have been consumed in space. For those who haven't tried it, kimchi is a fermented vegetable dish very popular in Korea and elsewhere, usually made from cabbage but sometimes radishes, with various additional spices added. Press reporting indicates that in 2008, a Korean astronaut did take kimchi to the ISS, but that kimchi was specially treated (irradiated) to kill the normally-live bacteria in it to avoid the danger of radiation-induced mutations(!) and to avoid problems associated with gas production. To quote one of the scientists involved, "Imagine if a bag of kimchi starts fermenting and bubbling out of control and bursts all over the sensitive equipment of the spaceship" (second linked press report above).
That got me thinking. Setting aside the issue of theoretically harmful mutations and smell, spacecraft are hardly strangers to dealing with pressurization. And here we have a self-pressurizing substance that is also edible and highly nutritious.
So, the question. Has anyone ever tried to make a sort of cold-gas thruster that derives at least some of its pressurization from fermentation or other biological activity? I haven't been able to find anything online.
I know the pressures involved would be small, but you also get to eat the reaction mass afterwards.
For what it's worth, I'm putting together a benchtop experiment and will revert with results. But has this ever been tried?
Please forgive any technical misstatements here. I'm in the industry, but not on the technical side!