When does CO2 production stop?

[BAOKBrewer]

I've had my first brew fermenting for two weeks now (planning to go at least three if the yeast decide to be finished by then) but wondered if CO2 production ever ramps completely down, even when the yeast are performing "clean up duties".

I'm not deciding the fermentation is complete when the airlock stops bubbling (which it still is) but this is more just a curiosity on my part.

 

[BeerJorge]

CO2 stops when fermentation stops...

If your beer is still bubbling after 2 weeks it's likely that you have wild yeast... have you taken any gravity readings?

Watch this video on yeast attenuation and fermentation problems...

 

[BAOKBrewer]

It will be two weeks tomorrow. The bubbling is extremely slow (like once every few minutes) and I've been testing for gas production by pressing on the lid of my bucket to drop the airlock down. I've opened it once for a gravity reading and it was just a couple points above the specified FG, and that was this last Thursday. I figured I would let it go to till this weekend (a little shy of three weeks) and bottle. It's an English Brown Ale with an OG of 1.064.

Would I be better off going ahead and bottling if my FG is where it should be? Everything looked and smelled fine when I took the gravity reading.

 

[jonmohno]

Most advice is to bottle if your hydro doesnt drop any between 3 days,if its at the fg-even better,but mine has went beyond the specified fg before. Thats weird that your airlock still bubbles that long, to me. Then again most of my airlocks dont even bubble. And i would say once every few minutes is probably not extremely slow.

 

[Smokeater233]

A still bubbling air lock can simply be off-gassing of the beer contained within and is NOT a sign of fermentation. Use your hydrometer and wait until you hit your FG or you get consistent readings over several days - and then leave it a bit longer to allow the yeast to clean-up after themselves.