Quick, probably dumb question. I know the amount of sugar I use to bottle carb is based on the temperature of my beer. But what if I cold crashed? Colder beer can hold more CO2 in solution, but after fermentation, where would this CO2 come from? So do I plug my fermentation temp into the calculator, or the cold crash temp?
I would use the temperature at the end of fermentation, or if the temp got any higher after fermentation, use that. Not the cold crash temp.
You want to use the highest temp your beer was stabilized at during fermentation. Not all the CO2 that the yeast create leaves the beer, rather it equalizes with the CO2 in the atmosphere. This is residual CO2. So pick the highest temp where the beer had an airlock for an extended time (think many hours) for this calculation. Also, for most ales at their normal temps (65 - 70), the difference in a couple of degrees is pretty minor so I don't sweat it too much.
That's what I figured it had to be. Thanks guys. A follow up: Do you let the temp come up to a regular ale temp before adding sugar and bottling? Or just add the sugar and bottle it cold while obviously letting it carb at room temp? Probably doesn't matter...
When a calculator asks you for a temperature, it's the highest temperature the beer has been after hitting FG. If you're cold crashing from a fermentation temp of, say, 68F, use 68F as your number that you plug into the calculator for for carbing. Feel free to package at your cold crash temp. No need to let the beer warm up.
