Stable FG but still have airlock activity

[Ant's]

Hi,

I've made an AG Saison using 3724 and then 3711 to dry it out. OG 1.057
It's been sitting at 1.006 (20c) for about four days but there is still allot of bubbles coming out the airlock.

In the past I've always had limited or no airlock activity when the SG was the same for so long.

Is it okay to crash cool now or should I wait? It's been in the primary for 5 weeks..

Cheers
Anthony

 

[Rocker1986]

I wouldn't take any notice of the airlock. All it means is that there is gas moving through it. Trust your hydrometer readings to determine whether fermentation has finished. What FG were you expecting?

 

[JDW81]

I reckon at 1006 it is probably done. If you've got stable readings then that is your best guide. Ignore the airlock, the only thing they airlock does is lead you up the garden path.

JD

 

[Ant's]

Great, thanks guys.

I was aiming for 1.006

 

[jaypes]

Airlock = $2 piece of shitty plastic
Hydrometer = calibrated scientific test device

 

[Alex.Tas]

Isn't it a sign there is some chemical reaction taking place that is releasing gas: therefore leading to bottle bombs?
Forgive my ignorance...

 

[hsb]

It can just be CO2 being released that the beer has absorbed during fermentation, no chemical reactions other than pressures equalising. Stick to hydrometer and common sense (ie; is there a krausen, have i achieved my expected FG, is the reading stable over several days) rather than paying any heed at all to airlocks (or kittens.)

Airlock bubbles don't mean fermentation is happening, nor does their absence mean it isn't. Use the hydrometer.

 

[wbosher]

From what I understand (happy to be corrected if I'm wrong), is that temperature can also cause CO2 to escape. As the beer warms up, more CO2 will be released from it. Possibly not relevant here, but maybe worth thinking about in future.

 

[Rocker1986]

...nor does their absence mean it isn't. Use the hydrometer.

Exactly. Mine never bubbles because the gas finds the easiest path out of the FV. I would guess that either the lid or the airlock grommet, or both, aren't totally airtight and thus the CO2 escapes this way rather than through the air lock. I'm not worried about it though. It does what it's meant to and the beer always turns out fine.

Also I believe you're right wbosher, more CO2 will escape the higher the temperature. Conversely, more will be absorbed (or stay in solution) at lower temps. This doesn't apply for cold crashing because there is no seal like on a bottle, therefore no pressure to drive the CO2 back into the beer, but it is true for bottles. That's why if you open one at room temperature they generally foam out the top, because more gas is escaping than if it was refrigerated. Also noticed it when I had one of those Heiny party kegs a few years back and let it warm up a bit.. poured a heap of foam into the glass. :lol:

 

[Ant's]

Thanks for all the advice.
I've crash cooled and will bottle on the weekend.

Cheers
Anthony