Bottle priming, after cold crash.

Ive looked through a few threads, and seems to be a bit of differing opinions on this. I figured I better ask before making 50 bottle bombs.

I fermented at 68°, cold crashed to 36° for 2 days, and now (not by design, forgot to wash bottles) its back up around 55° and I would guess will be close to 70° when I finally get to bottle. Is it a correct assumption to prime for the current temp even after the temperature bounce?

using this calc: http://www.tastybrew.com/calculators/priming.html for oatmeal stout, @ 2.4vCo2

Yep, prime for the warmest temp the beer was at during or after fermentation.

Any CO2 dissolved into solution will come out when the beer is warmed.


EDIT - You can't "add" dissolved CO2 at any significant level to a liquid just by chilling it. There has to be a source, like fermenting beer, to supply the CO2 at partial pressures higher than room air.

Pez.

RE-EDIT - Just thought of a scenario: If you start fementation at say 70, then drop to 64, and the beer is STILL fermenting, then prime at 64 as long as the beer stayed at this temp or colder when finished untill bottled.

How/Why do you prime based off of the beer's temperature?

redking11 said:

How/Why do you prime based off of the beer's temperature?

Click to expand...

Co2 will dissolve into a water solution at a higher rate the colder the solution is. This is true for 02 or any gas. When you are trying to reach a target of dissolved O2, this "baseline" must be accounted for.

I/E A beer fermented and kept at 64 degrees already has more dissolved CO2 in it then one fermented at 72 degrees - OR one that was fermented at 64 then allowed to rise and sit at 72.
Pez.

ok, are there charts that tell you how much more or less primer to use based on temp?

Yep, tons of them. Don't have any bookmarked, but a search on this site should bring up plenty.

OK, this is an old thread but better to revive it than dupe the topic.

I don't know how true the above is. I cold crashed a saison the other week to around 30F (outdoor temperatures) from final fermentation over 70F. It was only at crash temperatures for a day or two, certainly didn't do much CO2 production at that stage.

I added the recommended priming sugar for 30F (about 1.3oz sucrose), and I'd say it's spot on for the style--a little under 2 volumes. The recommendation for 70F is between 3 and 4oz sucrose. That's a big, big difference. I'd be drinking gushers if I'd primed at that level.

Either ambient CO2 absorption isn't as small a factor as people say, or something is seriously off with these calculators. I already get a .3oz difference between this calc and these two at 33F (picked because it is as low as one of them goes), so I'm getting pretty skeptical as to how useful any of these calculators can be given possible variations in dissolved CO2 due to temperature change and other factors. It seems like cold crashing throws a big wrench in the formulas they use.