Pitching Champagne Yeast to Finish My Imperial Stout

[Benighted]

Hey guys, I Brewed an imperial stout with an OG of 1.130, pitched 3 packs of US-05 and after 2.5 weeks it is down to around 1.042 and hasn't moved in the past week. I'm trying to get it down closer to 1.034. I tasted a sample of it and I am getting a flavor I believe to be acetaldehyde.

I was wondering if pitching some champagne yeast would help bring down the FG and get rid of the acetaldehyde? Thx guys!

 

[bigdawg86]

Pitch the yeast. Worst case scenario it doesn't drop but a few points. I would rehydrate the yeast before pitching though.

 

[couchsending]

Most imperial stouts have higher final gravities than that. I’ve degassed stouts with lower ABV that have higher FGs. Well regarded ones.

 

[Benighted]

Most imperial stouts have higher final gravities than that. I’ve degassed stouts with lower ABV that have higher FGs. Well regarded ones.

Fair enough. I wonder why I am getting that slight green apple thing going on? It's only been 2.5 weeks, should I just give it a lot more time?

 

[couchsending]

What temp did it ferment at

 

[couchsending]

So to the best of my knowledge champagne yeast can handle high alcohols but it can’t eat complex sugars which is most likely what’s left in your beer at this point. Maybe there’s some simple sugars but doubtful. If you do want to lower the gravity I would suggest the k1v-1116 wine yeast. It can handle super high alcohol levels and will ferment complex sugars and it’s POF-. It might also clean up any biproducts from the primary fermentation.

I’m not super familiar with other high ABV tolerant strains other than the high gravity yeast strain but that might consume everything and not sure you want that.

 

[bigdawg86]

I forgot to mention, if you wanted to go through the hassle try the yeast bay's dry belgian got my stout from 1.118 down to 1.012 over the course of several weeks.

 

[Benighted]

What temp did it ferment at

I fermented at 66 and left it free rise up to 70 after a week.

 

[minihack]

There’s an enzyme you could use in moderation called amylase that will break sugars down so you can use said wine yeast.. I have very little experience with it saying that I have used it twice on a Belgian yeast that stalled.. learned from that to just do an open ferment.. now knowing that it will thin the body down.. but I fermented to 0* you may not get that using this in moderation..

 

[z-bob]

Do not use champagne yeast. It will not ferment maltotriose, plus it will kill any beer yeast you have left (or try to add later when the champagne yeast doesn't work) It will work for bottle-conditioning (carbonating.) Like Couch said, K1V-1116 might work. I've used it in beer once and it did very well.

 

[Steveruch]

Fair enough. I wonder why I am getting that slight green apple thing going on? It's only been 2.5 weeks, should I just give it a lot more time?

I'd give it more time.