2nd batch. Will be in fermenter for 3 weeks tomorrow. I checked the gravity on Tuesday and then again today, no change. However, I can see it is still bubbling in the airlock. It is only 1 bubble maybe once every 15 minutes or so, but still bubbling. I was planning on bottling tomorrow. Would you wait or would you go ahead and bottle tomorrow?
If those identical readings were in the neighborhood of where you expected to end up, you can be pretty sure attenuation is finished. That little bit of bubbling you're seeing is probably due to off-gassing of CO2 as it seeks equilibrium with the atmosphere, and not due to new CO2 being produced by yeast.
That is beer is ready for bottling; no need to wait. And while each batch is unique, 3 weeks is plenty of time for primary fermentation to complete. Cheers!
