Bubbling Air Lock is Meaningless

[Mad Chemist]

I have heard it said many times on this forum that bubbles in an airlock is meaningless. I understand that if the air lock is not bubbling the fermentation process is not necessarily complete. And maybe it is possible to have bubbling air lock without fermentation. (Although that is exactly what is supposed to cause the bubbles)

But bubbles in the airlock does mean something. Therefore it is not meaningless. I know this will frustrate some of you very much. It may even result in a response in all CAPS. So be it. I am willing to live with the consequences. Therefore my question is this:

If a 2.5 gallon batch is still bubbling after 3 weeks and the SG is stable at 1.004 and it goes in the fridge for 2 days to cold crash and I pull it out and it still pops a bubble every couple of minutes......what does it mean? If the bubbles are not from the yeast giving off co2, then why?

Signed.....perplexed.

PS.....can the SG drop to less than 1.000?

 

[The Brew Mentor]

During the fermentation, the wort/beer was saturated with co2. Even though the beer sat still and under an airlock for some time, the beer still retained some of the gas. When you chilled the beer the co2 in solution actually was more stable (co2 dissolves better in lower temperatures). When you warmed it back up, the gas was able to come out of solution some more and that's why you're seeing a bubble every now and then.

If your beer was stable for 3 days, the yeast has consumed enough of the sugars to go ahead and bottle. The yeast will continue it's clean up but the fermentable sugars are mainly gone.

I've had beers get down to 1.000 but that wasn't the target.

I hope this helps.

Brian

 

[Mad Chemist]

That makes sense. Thanks for the reply.