beer fermented at 63F for a few days then free rose to 70F over a couple of days and stayed there for a couple of weeks. I currently have the beer in an ice bath but it is not getting below 55F and is usually closer to 60F.
What temp should enter for residual CO2 calculations? I don’t bottle very often and in the past, I tried to keep my temps pretty constant.
I would think it depends on how active co2 production was at those various temps. If fermentation was basically done at 70° and you then lowered the temp, I’d go with that. The difference in the amount of priming sugar needed isn’t so much that I would worry about bottle bombs.
Thanks. Normally, I wouldn’t worry but this is a smaller batch with less room for error. You are correct in the difference in priming sugar isn’t huge so hopefully it won’t matter too much.
I guess it also depends on style. Maybe hedge your bet in the middle.
Its a high ABV baltic porter that finished pretty low. I may carb it a bit less than normal to reduce a bit of the bite that I am afraid it will have.
I found out via a under carbonated batch of porter that you need to use the highest temp the beer reaches after fermentation is complete. The reason is this, The temperature is used to adjust your priming sugar amount to compensate for the amount of Co2 retained in the beer. Again, this compensation is temperature based.
When beer gets warm Co2 comes out of solution. If fermentation is complete then there is no more Co2 being produced, so even if the beer gets cooler again it will maintain the same Vol of Co2 as when it was at the warmer temperature. So going with the lower temp will result in low/inaccurate Vol’s of Co2.
See also this recent topic: https://www.homebrewersassociation.org/forum/index.php?topic=24237.msg308981#msg308981