I have a question for those who are more chemistry-aware than I. When bottle conditioning, I understand the reasoning behind calculating the priming sugar based upon the warmest temperature the beer had been at, namely that warmer liquids hold less CO2 than colder liquids. I was wondering about the setup I have, which is a small chest freezer. I have an ale that has been fermenting in the low 60's, and I let it warm up to the upper 60's for a few days. If I cool it back down, for all intents and purposes my chest freezer is filled with CO2. When the beer cools back down, does it take up the CO2 again in any significant amount, or do I still use the higher temperature in my carbonation calculation? For the ale it is largely an academic question because the difference isn't that great, but I will be getting into lagering for the first time soon and there it can have a larger difference.
I can convince myself that the beer wouldn't take up additional CO2 because when it was colder it was in a supersaturated state and I wouldn't think the CO2 would diffuse back into solution such that it returns to a supersaturated state; however, at this point I'm arguing from the gut because I don't have much of a chemistry leg to stand on.