fermonster
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Hey all, this is one for the slightly sciencey brewers....
Just interested if anyone knows the different gases released during stages of fermentation. I use a chronicle fermenter and don't do secondary fermentations to minimize oxygen exposure, but do sometimes dump yeast and leave it in the fermentater for a short secondary.
What happened what I fermentated the same lager recipe for 5th time, so pretty much understood what was happening. This time I never opened the fermenter or took off the air lock to not expose the beer at all. Usually I'll take of the lid and take a peek a couple of times to see krausen dropping.
When bottling, I noticed really rapid rising of bubbles, almost like a slightly flat carbonated beer. What I expect is that the air lock pressurizing the beer a little and not all gas had been released yet and some was in solution, so the beer seems to be carbonated. I've stopped bottling and giving it some time with just tin foil of air lock to let it gas off.
My thinking is that this gas is just Co2 at the end of fermentation held in the beer and being released when out of the pressure environment of an unopenned fermenter.
These paper abstract talk about hydrogen sulfide production dropping off at end of fermentation, but I'm not clear what gases happen at different stages.
https://www.khanacademy.org/science...tion/a/fermentation-and-anaerobic-respiration
https://www.ncbi.nlm.nih.gov/pubmed/18930001
Obviously best to let beer sit in fermenter until no gas and let bottle / keg process carbonate. Just wondering the science of it, and if the few bottles I did package will just be slightly more carbonated with Co2 or if the gas is a nasty diacetyl pre-curor or something equally nasty.
Beer is super clear and finished at 1.012 so I'm pretty confident fermentation is complete. I did a good diacetyl rest.
Thoughts on the science of this welcome.
Just interested if anyone knows the different gases released during stages of fermentation. I use a chronicle fermenter and don't do secondary fermentations to minimize oxygen exposure, but do sometimes dump yeast and leave it in the fermentater for a short secondary.
What happened what I fermentated the same lager recipe for 5th time, so pretty much understood what was happening. This time I never opened the fermenter or took off the air lock to not expose the beer at all. Usually I'll take of the lid and take a peek a couple of times to see krausen dropping.
When bottling, I noticed really rapid rising of bubbles, almost like a slightly flat carbonated beer. What I expect is that the air lock pressurizing the beer a little and not all gas had been released yet and some was in solution, so the beer seems to be carbonated. I've stopped bottling and giving it some time with just tin foil of air lock to let it gas off.
My thinking is that this gas is just Co2 at the end of fermentation held in the beer and being released when out of the pressure environment of an unopenned fermenter.
These paper abstract talk about hydrogen sulfide production dropping off at end of fermentation, but I'm not clear what gases happen at different stages.
https://www.khanacademy.org/science...tion/a/fermentation-and-anaerobic-respiration
https://www.ncbi.nlm.nih.gov/pubmed/18930001
Obviously best to let beer sit in fermenter until no gas and let bottle / keg process carbonate. Just wondering the science of it, and if the few bottles I did package will just be slightly more carbonated with Co2 or if the gas is a nasty diacetyl pre-curor or something equally nasty.
Beer is super clear and finished at 1.012 so I'm pretty confident fermentation is complete. I did a good diacetyl rest.
Thoughts on the science of this welcome.
