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Moving this from the Beginners Forum, but wasn't sure where to put it. It could go to Fermantation and Yeast or even the Bottling Forums, but in any case I thought it deserved its own thread.
There have been two schools of thought on how CO2 gets into our beer during natural carbonation. There was a thread here on HBT a while back and a BYO article that promote the idea that the CO2 goes into the head space and then is absorbed into the beer until it reaches equilibrium for that temperature. The other is best represented by this quote from Bobby_M.
Both make sense to me, but are contradictory, so I wanted to try to repeat the experiment with some better controls in place. For now I have a temperature probe attached to the side of the steel container. I don’t think that there is too much heat being produced by this level of fermentation, and from experience, I don’t think the liquid temperature will be significantly different from the reading at the surface of the container. Still, depending on how this goes, I may repeat it with a temperature controlled bath.
My biggest drawback is that I don’t have a way to monitor the experiment other than visual observations. Still, what I’m looking for is a peak in pressure and then a leveling. If I get this, I’ll know that further trials are needed.
Any comments or suggestions are welcome.
Edit to say:
It's been one week since starting this experiment. The pressure went up to about 20 psi over a few day and (accounting for temperature) has stay there. That combined with the logic and science of Bobby, ajdelange and others has me convinced that there is no build up of CO2 in the headspace prior to absorbsion.
The setup
There have been two schools of thought on how CO2 gets into our beer during natural carbonation. There was a thread here on HBT a while back and a BYO article that promote the idea that the CO2 goes into the head space and then is absorbed into the beer until it reaches equilibrium for that temperature. The other is best represented by this quote from Bobby_M.
As yeast are releasing CO2, it's one molecule at a time. A single CO2 molecule in liquid is already considered dissolved. Because the source of CO2 in bottle conditioning is in the liquid already the liquid will always have the higher concentration of CO2 compared to the headspace until no more CO2 is being produced. At that point equilibrium is reached and the concentration will be equal.
Both make sense to me, but are contradictory, so I wanted to try to repeat the experiment with some better controls in place. For now I have a temperature probe attached to the side of the steel container. I don’t think that there is too much heat being produced by this level of fermentation, and from experience, I don’t think the liquid temperature will be significantly different from the reading at the surface of the container. Still, depending on how this goes, I may repeat it with a temperature controlled bath.
My biggest drawback is that I don’t have a way to monitor the experiment other than visual observations. Still, what I’m looking for is a peak in pressure and then a leveling. If I get this, I’ll know that further trials are needed.
Any comments or suggestions are welcome.
Edit to say:
It's been one week since starting this experiment. The pressure went up to about 20 psi over a few day and (accounting for temperature) has stay there. That combined with the logic and science of Bobby, ajdelange and others has me convinced that there is no build up of CO2 in the headspace prior to absorbsion.
The setup