Beer started bubbling months later?

[aorloski]

So i have had this imperial stout sitting in primary for about a month, transfered it about 2 weeks ago to secondary ontop of some carraway seed and cocoa nibs, just today the airlock started bubbling again and it looks like the top of the beer has a dark brown layer of krausen on it? i took numerous readings on this thing and came to the conclusion the fermentation stopped a long time ago, now i am just letting it sit to get some more flavor. Anyone know why it is bubbling again? could it be a possible infection?

 

[solbes]

It could be eating some addtional sugar that was left behind in primary. What was your OG and FG in primary? I doubt you have an infection, esecially given the usual high alcohol and added hops present in RIS recipes. Did you sanitize your nibs or seeds in any way?

Mine dropped some more in secondary, but I added a hopped starter at high krausen with the intent of dropping it lower. Turned out great!

 

[aorloski]

OG 1095 FG 1030, a bit on the sweeter side but tasting it out of primary i actually really liked the taste, no cloying sweetness just a lot of mollasses on the tongue which i want since im trying to make a pumpernickel stout. the nibs were not "sanitized" but i did roast them which should have killed any bacteria. This thing hasnt bubbled in months so i am just kind of weirded out!

 

[sweetcell]

could be an infection. is there a lot of headspace in your secondary?

something similar happened to me: transferred a pretty big stout to secondary and it started bubbling about 1.5 months later. i had a lot of empty headspace in my secondary, that allowed either a wild yeast or bacteria to take hold. made the stout... interesting. it's still drinkable, and sour beer aficionados quite like it. not my fav, tho.

but that's my experience. yours could be entirely different.

 

[aorloski]

its in a 5 gallon carboy with pretty minimal headspace! maybe about an inch past the headspout.

 

[solbes]

At 1.030, there are still some sugars left there. But its a difficult environment for the yeast to work in. I doubt an infection has taken hold. It might even drop a few points, 1.025 would be great for an RIS.

 

[WoodlandBrew]

I bet it is just CO2 coming out of solution. Especially because of the small head space. The krausen is curious. Could it just be yeast rafts? You might get a couple more gravity points out of it by the agitation that occurred during racking.

This talks about the number of days needed between specific gravity measurements to ensure completion:
http://woodlandbrew.blogspot.com/2012/11/when-has-my-beer-finished-fermenting.html

 

[kcross13]

I usually get a little refermentation when I transfer to secondary. Rousing the yeast a little in the transfer I guess, as well as off gassing. If it doesn't taste nor look nasty, I bet it isn't.