fermenting in a vacuum?

[Descender]

Was thinking of trying an experiment. One 2 liter bottle fitted with an airlock, and one 2 liter bottle that is 2/3 full with the air squeezed out and the regular cap on, creating a small vacuum. Any thoughts from the scientists?

 

[D0ug]

you'll probably pop the cap or rupture the sealed soda bottle, the yeast will produce many times the volume of Co2 over the course of the fermentation than is available in the dead space of the sealed bottle.

 

[cluckk]

The CO2 produced in fermentation will fill the empty space, expand the squeezed bottle, and most likely blow something out from pressure.

 

[gratus fermentatio]

You'd need to remove the CO2 generated by the yeast, basically as it's generated to maintain a vacuum. You'd also have to wait until the aerobic stage of the yeast is done & they've switched to the anaerobic stage. Yeast requires O2 at the beginning of fermentation. Not sure how the yeast would react (if at all) to the absence of pressure though. Contact Lallemand or Red Star, they'd likely know.
Regards, GF.

 

[Descender]

Was planning on letting the accumulated gas out and then squeezing out the remainder of headspace constantly to maintain a slight vacuum

 

[pickles]

Was planning on letting the accumulated gas out and then squeezing out the remainder of headspace constantly to maintain a slight vacuum

You have to have a vacuum pump and vacuum switch to maintain a constant vacuum. The slightest bit of co2 generated will create positive pressure, so there may be a vacuum the moment after you burp the bottle but it won't last but a few minutes.

 

[WilliamSlayer]

you'd need to remove the co2 generated by the yeast, basically as it's generated to maintain a vacuum. You'd also have to wait until the aerobic stage of the yeast is done & they've switched to the anaerobic stage. Yeast requires o2 at the beginning of fermentation. Not sure how the yeast would react (if at all) to the absence of pressure though. Contact lallemand or red star, they'd likely know.
Regards, gf.

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