Continued airlock activity after 5 weeks

[porkbelly]

Brewed an old ale. OG 1.092, expected FG 1.032 with WLP002. Other than a smaller than expected krausen, fermentation seemed to go normally. After 4 weeks I took a sample, found SG at 1.028 and assumed it was done even though there is still airlock activity. It's not super active, but enough to keep foam on the starsan in the airlock. Taste seemed nice and malty, nothing unusual.

Now it's 4 days later, airlock activity hasn't seemed to change, took another sample to confirm gravity, still at 1.028. Only today, the aroma and flavor seemed to have changed and it seems a little off. Can't say for sure what's expected as this was a new recipe.

So the question: Is the airlock activity a sign of infection or normal CO2 release? Temps have been controlled between 65-68 ambient as well as the reading on the fermometer on the carboy. No pellicle has formed and nothing is growing on the side of the carboy. Opinions?

 

[Glynn]

your fg hasn't changed in 4 days, its done bottle it. it was most likely done 2 to 3 weeks ago. Don't use the airlock as a sign that its done, they are evil and like to play with your mind.

 

[porkbelly]

Yes, I agree the beer is done and ready to be bottled. The question I posed still stands.

I like to think I can tell the difference between young and off at this point. Given I *think* it's off, and in all my batches I've never had airlock activity continue like this with comparable gravity beers, is it more likely an infection, or dissolved CO2 equalizing with atmospheric pressure?

 

[Fid]

I'd assume if it was an infection you'd be seeing a change in your gravity readings. Your fg is lower than expected but fg estimates are just estimates. Also, that is a pretty large beer, I'm not surprised that it might taste "off" after only 5 weeks. Bottle it, give it another 5 weeks, and then start to critique it.