Bubbles on top after 3 weeks

[elgrindio]

Hey everybody. Just wanted your opinion about this:

This is a heavy porter that has been in the fermenter for almost 3 weeks now. Initial fermentation seemed to go fairly normal. OG 1.078, now settled at around 1.020. Hydrometer readings 2 days apart were the same. Tastes good, so I’m not super concerned, more curious. These bubbles never go away. I swirl the beer around, it produces a light foam which goes away fairly quickly, but these bubbles stay. Any thoughts? Thanks ahead of time!

 

[Funky Frank]

Did you add any adjuncts? Maybe something oily? What yeast did you use?

 

[elgrindio]

Nope... I did add a pound of boiled brown sugar water after 3 days. That’s as crazy as it gets.

 

[IslandLizard]

Probably from some outgassing. There could still be some slow fermentation going on too, not uncommon with larger beers when you didn't ramp the temps up toward the end of the more active event.
Beer clarifying (yeast dropping) is another sign it's about done. Dark beer becomes darker, less looking like chocolate milk.

I'd give it a few more days, take another reading and when the same, package away.

 

[jdauria]

CO2 escaping from the beer most likely.