Cold crash airlock?

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kjm13

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This may be a stupid question, but this is the first time I have cold crashed... Is it normal for the airlock to start bubbling again during the cold crash?

Thanks.
 
Seems kind of strange..Unless it got hot making your yeast go dormant and then when you cold crashed it, the yeast 'woke up'
 
Is this at the beginning of the cold crash? It could be that when you moved the fermenter the beer moved around and CO2 in suspension started bubbling up. It takes a good day or two before the beer gets cold. It should start doing the opposite when the beer gets cold and try to suck air in.
 
It will bubble backwards when cooling as the gas in the headspace contracts. This is why its important not to leave your blowoff tube connected!
 
It is as more then 24h into the cold crash when the bubbling started! And it's bubbling forward, not back. Max temp during the ferment was 67 and that was only for the first day. It was 64 when I put it in the fridge...
 
It will bubble backwards when cooling as the gas in the headspace contracts. This is why its important not to leave your blowoff tube connected!


Yeah. That's what I've read, and why I changed the blow off to a standard airlock with vodka in it before I put it in the fridge. Why on god's green earth is it bubbling forward?! Planning on bottling tomorrow. FG was a little high at 1.017 (although there is a ton of rye in it) but it's at ~ 35 F° now. Can't be any way it's actively fermenting is there? Of course I smashed my hydrometer on Sunday so I can't even check gravity...
 
The high FG is one clue. The yeast used must have a low temp for the temp it can get down to & still ferment? It must've stalled & woke up again!?:mug:
 
The high FG is one clue. The yeast used must have a low temp for the temp it can get down to & still ferment? It must've stalled & woke up again!?:mug:


I used wyeast American ale II. Was 3 weeks in at time of cold crash...
 
It says the temp range is 60-72F, so you're in the low range for that yeast. It also says low end gives a light citrus character. Medium-high flocculation as well, so it should drop clear.
 
"...it's at ~ 35 F° now."

Is that ambient or beer temp? I suspect, as someone else inferred, you may have sloshed the beer when putting it in the fridge enough to wake up the yeast, esp. at the slightly high FG. Although it would take a day or so for the entire batch to get down to 35F, the re-awakening had already started and it would continue for a short time past the actual 35F of the beer itself.

Sounds like you're in a hurry to bottle, but if it were me, I would take it out of the fridge, give it another gentle slosh and leave it at room temp for a few days. Meanwhile, get yourself another hydro and re-check it. I think you might find your FG has dropped a couple points, which would be a good thing. Then C-C again. If you have unfinished ferm @ C-C, then warming it back up for bottling and adding priming solution, you could end up with bottle bombs. Gotta make sure that baby is DONE before you bottle.
 
"...it's at ~ 35 F° now."



Is that ambient or beer temp? I suspect, as someone else inferred, you may have sloshed the beer when putting it in the fridge enough to wake up the yeast, esp. at the slightly high FG. Although it would take a day or so for the entire batch to get down to 35F, the re-awakening had already started and it would continue for a short time past the actual 35F of the beer itself.



Sounds like you're in a hurry to bottle, but if it were me, I would take it out of the fridge, give it another gentle slosh and leave it at room temp for a few days. Meanwhile, get yourself another hydro and re-check it. I think you might find your FG has dropped a couple points, which would be a good thing. Then C-C again. If you have unfinished ferm @ C-C, then warming it back up for bottling and adding priming solution, you could end up with bottle bombs. Gotta make sure that baby is DONE before you bottle.


I'm in a bit of a hurry to bottle... Really want this to be ready to drink by Christmas, and I was trying to do this 5 week grain to glass thing everyone seems to be talking about. I've always left my beers much longer, (like 2 months), but wanted to try this route. Also only wanted dry hops in for 7 days total.

The gravity was 1.018 at 2 weeks, and then I left it alone at room (cellar) temp of about 64F° for another week, and was at 1.017 when I put it in the fridge. Am I incorrect that beers with a large percent of rye in the grain bill will usually have a higher final gravity?

I don't want bottle bombs for sure... I'll go get another hydrometer. If it is still 1.017, think I'm safe to bottle?
Thanks!
 
Your beer's done

No need for any more gravity readings.

It's had ample time.

Cold crash away and take the pointless airlock off. Cap it with sanitized foil and rubberband or a carboy cap. Simple. No more bubbling to worry about.

Cold Crashed Beer.jpg

You move a carboy and you will kick CO2 out of suspension. That's what happened. It's not possible for Wyeast 1272 to be active at 35F.

The beer and air in the carboy will contract when you crash cool it. A 3 piece airlock will empty into the beer or freeze (whichever comes first). An S-airlock will bubble the wrong way or freeze. Solution. No airlock

35F. You can crash lower if you want and have the ability. I do 31F and could probably go lower still.

Your absolutely safe to bottle. No worries.
 
Your beer's done

No need for any more gravity readings.

It's had ample time.

Cold crash away and take the pointless airlock off. Cap it with sanitized foil and rubberband or a carboy cap. Simple. No more bubbling to worry about.

View attachment 321530

You move a carboy and you will kick CO2 out of suspension. That's what happened. It's not possible for Wyeast 1272 to be active at 35F.

The beer and air in the carboy will contract when you crash cool it. A 3 piece airlock will empty into the beer or freeze (whichever comes first). An S-airlock will bubble the wrong way or freeze. Solution. No airlock

35F. You can crash lower if you want and have the ability. I do 31F and could probably go lower still.

Your absolutely safe to bottle. No worries.


Thanks Gavin. Just so strange the airlock was bubbling forward. 34/35F° is as low as I can go unfortunately... I got a chest freezer and a temp controller, but it wouldn't go below 53F° after 8h. That's what you get for buying a $50 freezer off Craig's list I guess. At least it woks for hold ferment temps at 64. So I'm back to the fridge on the lowest setting for the cold crash. Thermometer I have in there says 34F°

How long before I bottle should I take it out of the fridge? A couple hrs to warm up or is straight out of the fridge fine?
 
How long before I bottle should I take it out of the fridge? A couple hrs to warm up or is straight out of the fridge fine?


No worries mate.


  • Take it out and place it as needed
  • Prep priming soln. in microwave/ on stove
  • Chuck solution into bottling bucket
  • Bottle right away

No need to wait for the beer to warm up. If anything it can be counter productive to wait. In theory kicking more CO2 out of suspension and stirring up trub.


*When calculating how much priming sugar be sure to use the warmest temperature the beer got to after fermentation not the cool temperature.
 
...Just so strange the airlock was bubbling forward.

Which was my point. I've never had a finished beer bubble back through the airlock when moving it to C-C, or anywhere else for that matter. What I suggested was what I would have done, but that's just me. Hope it turns out well in time for Christmas.
 
When I cold crash I noticed the same thing that my air lock would start bubbling again. But then I realized you have all of that Co2 in the head space so really when I moved it the pressure on the carboy or bucket (plastic) would make the airlock boil, so I figured when I opened my fridge if it shakes the bucket a little it will also make the airlock bubble. I think you are fine though...don't sweat it.
 
I'm probably too concerned with keeping my beer from getting exposed to air but when I use carboys I fix a sanitized balloon filled with CO2 on them before cold crashing.

2015-08-06 19.32.42.jpg
 
No worries mate.


  • Take it out and place it as needed
  • Prep priming soln. in microwave/ on stove
  • Chuck solution into bottling bucket
  • Bottle right away

No need to wait for the beer to warm up. If anything it can be counter productive to wait. In theory kicking more CO2 out of suspension and stirring up trub.


*When calculating how much priming sugar be sure to use the warmest temperature the beer got to after fermentation not the cool temperature.


I usually just use the amount of priming sugar Beersmith tells me.... Should I do something different? BS says to use 3.6 oz of corn sugar for 2.3 vols of carbonation.
 
I usually just use the amount of priming sugar Beersmith tells me.... Should I do something different? BS says to use 3.6 oz of corn sugar for 2.3 vols of carbonation.

If that's the calculator you use with success, no need to make any changes to your usual method. Just don't enter the beer temperature as 35F. That's all I was saying. If 2.3 volumes is what you want that sounds about right for a 5 gallon batch. I'm not well versed in that area though.
 
I'm probably too concerned with keeping my beer from getting exposed to air but when I use carboys I fix a sanitized balloon filled with CO2 on them before cold crashing.

Looks like a party in there! :rockin:
 
Which was my point. I've never had a finished beer bubble back through the airlock when moving it to C-C, or anywhere else for that matter. What I suggested was what I would have done, but that's just me. Hope it turns out well in time for Christmas.

Thanks for the feedback! It's been in the fridge since Sunday. Last night the airlock was still bubbling forward... I know the yeast can'T be active at that temp for that long, so I guess it must be C02 coming out somehow. I'll bottle tonight unless I get a crazy hydrometer reading. Just so curious - I'll have to check it....
 
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