Lengthy Fermentation

“Lengthy” is a relative term…but here’s the background:

Brewed the NB Caribou Slobber last Saturday (1/7). I was working with a buddy and we also did the Bourbon Barrel Porter. We pitched both of them at 66 - 68 F wort temp. Things went merrily on their way for several days…the porter krausen rose almost into the carboy neck and has since fallen down and is all gone now…however the caribou slobber still has a good inch on it and it’s not going away…I’m not seeing the customary “action” in the beer under the krausen…totally still.

Any ideas on why this would happen? I assume it is still fermenting, But all the other 5-6 extract kits I’ve done have mostly finished visbile signs of primary fermentation within a 4-5 days like the porter has done.

Why is the slobber being such a slowpoke?!?

Just one of the interesting puzzles I have been contemplating while enjoying the fruits of previous labors!

Thanks,
Bob

I wouldn’t expect a typical fermentation to complete in less than two weeks. The presence of krausen isn’t a very good indicator either way - when it first drops there is still plenty of activity going on as the yeast work to clean up after themselves and I’ve had a thin krausen stick around long after terminal gravity was reached.

Don’t sweat it, just leave the beer alone for at least another week, preferably two.

Did you mean you would?

I was wondering that as well. Most of the kits I have made so far have essentially completed primary within a week, then I have put into secondary to make room in the primary again. I have measured gravity over a few days in all cases to be sure that things were wrapped up. Hmmmm… Am I missing something?

Did you mean you would?[/quote]No, it takes 2-3 weeks for fermentation to complete. There are always exceptions to the rule, like low-gravity ales, but in general I find that I make the best beer when I let the yeast have plenty of time.

How are you gauging that? My ales reach FG in about 2-7 days, depending on gravity. That’s pretty much in line with what I hear from others as well.

Terminal gravity isn’t the point at which fermentation is complete, it just indicates that the yeast are done chewing through the available sugars at a rate that produces a noticable change in gravity. What do you do with your beer at the 7-day mark? Rack it to a keg, carb, and drink it at 10 days post-pitch?

That’s a little more aggressive than average, but basically, yes. Unless I’m dry-hopping I have my average-gravity ales on tap by the 14 day mark.

And terminal gravity is the point at which fermentation is complete. There’s metabolism that goes on beyond that, to be sure, but that’s conditioning, not fermentation.

[quote=“a10t2”][quote=“Shadetree”]What do you do with your beer at the 7-day mark? Rack it to a keg, carb, and drink it at 10 days post-pitch?[/quote]That’s a little more aggressive than average, but basically, yes. Unless I’m dry-hopping I have my average-gravity ales on tap by the 14 day mark.[/quote]Just does to show you that different brewers use different techniques - I prefer to let my ales go about three weeks in the fermenter before racking and then another week or so before drinking.

[quote=“a10t2”]And terminal gravity is the point at which fermentation is complete. There’s metabolism that goes on beyond that, to be sure, but that’s conditioning, not fermentation.[/quote]I find that the beer will drop a point or two during the “conditioning” phase so fermentation is still happening during the 7-10 days that the beer sits in primary after the krausen drops. Almost all my beers are dry-hopping during this time, though.

I’m with Shadetree on this one - my ales typically get 2-3 weeks to ferment and condition in the primary. Conditioning does seem to work better when the beer is sitting on the yeast cake, though that will sometime add additional clearing time needed.

That used to be my process too. It was actually when I started brewing professionally that I became interested in faster turnaround times. As a result of that I started decreasing the conditioning times on my home brews as well, and found that I couldn’t really tell the difference between 2-3 days of conditioning and 2-3 weeks. For average-gravity ales, anyway.

Interesting. I haven’t seen that. If you were someone less experienced I’d suggest that it could be due to a very low-level contamination issue. I’m sure you have your ducks in a row as far as sanitation though. Just out of curiosity, do you ever do wort stability tests?

I’ve found my beers, on average, to be better tasting and smoother if I let them age out a bit. Usually my last glass is the best glass of the keg.

I will eventually do an experiment to test this first hand, side by side identical batches, minus time. I know of another pro brewer who goes 10 days boil to tap in his brew pubs and I’m pretty sure he’s making good beer. I just don’t know if it’s GREAT beer. The only way I’ll be convinced is to try it first hand.

[quote=“a10t2”]Interesting. I haven’t seen that. If you were someone less experienced I’d suggest that it could be due to a very low-level contamination issue. I’m sure you have your ducks in a row as far as sanitation though. Just out of curiosity, do you ever do wort stability tests?[/quote]No, infection isn’t the cause, the gravity remains stable once it’s finished (if it didn’t, I would do a wort stability test, but my sanitation regime is solid). I think that adding the dryhops and letting the beer sit another week just lets the yeast very slowly eek out a little more EtOH. You could call that the “terminal gravity” I guess. :wink:

Another point of difference might also be the use of the term “average gravity”: that’s 1.060 - 1.075 for me, pretty much never make anything lower than that.