Stuck Fermentation?

[tld6008]

I just kegged a Hopslam clone which I had successfully brewed twice before. Prior fgs were 012 and 017 at 12 days. This batch was at 022 at 20 days (sg had been stable for 3 days) and I needed to make room in my ferm chamber for a new batch so I kegged it. After carbing up the beer it just tastes too sweet. Yeast was 1056 harvested from a blonde ale and frozen w/glygerin. A starter was made and stepped up twice. This was the only difference in the recipe from what I had done previously. I was thinking of letting the keg go flat by offgassing and introducing some new yeast to see if it will ferment any further. Mash temp was 150f and og was 082, everything else besides the yeast was as the previous batches.
I am assuming there are unfermented sugars remaining so my question is does this make sense and if so what yeast would do a good job?

 

[RM-MN]

My first thought is why did you leave it in the fermentation chamber so long? It only needs temperature control during the initial fast part of the fermentation, say 3 or 4 days. After that let it warm to room temp. That warmer temp encourages the yeast to complete the job before they settle out. That also frees up your fermentation chamber so you can brew the next weekend.

You're going to have trouble getting another yeast to do much. All the easy sugars are gone, there is alcohol in there (nearly 8%), and the atmosphere above the beer is mostly CO2, not the O2 the yeast need to multiply. Probably the best course now it to let the keg warm to room temp or a little warmer and swirl it to get as much of the settled yeast back in suspension and give it time to work.

 

[JohnSand]

I've had beers finish a little high and sweet from kettle caramelization.
You could try to balance it with dry hopping, or hop tea.

 

[tld6008]

My first thought is why did you leave it in the fermentation chamber so long? It only needs temperature control during the initial fast part of the fermentation, say 3 or 4 days. After that let it warm to room temp. That warmer temp encourages the yeast to complete the job before they settle out. That also frees up your fermentation chamber so you can brew the next weekend.

You're going to have trouble getting another yeast to do much. All the easy sugars are gone, there is alcohol in there (nearly 8%), and the atmosphere above the beer is mostly CO2, not the O2 the yeast need to multiply. Probably the best course now it to let the keg warm to room temp or a little warmer and swirl it to get as much of the settled yeast back in suspension and give it time to work.

I do let the fermentation temp rise to 72f for a day or so but in this case it was about 5 days and primarily to finish fermentation rather than the usual cleanup rest. My typical room (garage) temp is 80-90f other than in winter so fermentation is always done in a controlled chamber and only removed when time to keg.
Thanks

 

[tld6008]

I've had beers finish a little high and sweet from kettle caramelization.
You could try to balance it with dry hopping, or hop tea.

That is an interesting thought, how can you tell if there has been carmelization? There are no visible signs in the kettle and beer color is about what it should be. I do have a tendency to boil very aggressively due to the volume of water I end up using during the sparge. My DIY burner would likely burn a hole in the kettle bottom if I opened it up. That's another problem I feel I have as I need to use 10 gal of water to get my runoff gravity down to .020

 

[JohnSand]

I think I generally judged it by taste, and by high final gravity. I think I've had the problem mostly when using liquid extract, which I've stopped using. The other time it occurred I was doing a decoction to raise mash temps. While mixing in some of the decocted mash, I let the rest of it come to a hard boil. That darkened and sweetened noticeably, with an effect on the finished beer.

 

[Gameface]

My first thought is why did you leave it in the fermentation chamber so long? It only needs temperature control during the initial fast part of the fermentation, say 3 or 4 days. After that let it warm to room temp. That warmer temp encourages the yeast to complete the job before they settle out. That also frees up your fermentation chamber so you can brew the next weekend.

You're going to have trouble getting another yeast to do much. All the easy sugars are gone, there is alcohol in there (nearly 8%), and the atmosphere above the beer is mostly CO2, not the O2 the yeast need to multiply. Probably the best course now it to let the keg warm to room temp or a little warmer and swirl it to get as much of the settled yeast back in suspension and give it time to work.

I leave my fermenter in the temp chamber until I keg it. First, because I don't want to slosh it all around when I don't have to. Second, because I'm eventually going to cold crash it. I currently make 10G batches, so hauling 80lbs in and out of the fermentation chamber is not something I want to do extra times.

 

[tld6008]

What about using that CBC-1 yeast?