Stuck Fermentation on Really Big Imperial Stout

[flow415]

Well guys, looks like nothing happened even after adding that alpha amylase, waiting a couple weeks and then adding the Belle Saison yeast... not sure wtf's going on at this point. I'm assuming there's still a lot of non digestible sugars in there. Any other suggestions? It's really sweet. I may end up just following through with the rest of my recipe of adding cacao nibs, toasted marshmallow extract and then kegging it. It's definitely going to be a really sweet 8.5% stout.

 

[IslandLizard]

Any other suggestions? It's really sweet. I may end up just following through with the rest of my recipe of adding cacao nibs, toasted marshmallow extract and then kegging it. It's definitely going to be a really sweet 8.5% stout.

Yes: Enjoy it for what it is.

Add your marshmallow extract, cacao, vanilla, whatever you see fit.
Perhaps put a bottle of Bourbon next to the tap or on the drip tray. Raising the alcohol a tad that way, plus adding its flavor, can make all the difference.

 

[mac_1103]

looks like nothing happened even after adding that alpha amylase, waiting a couple weeks and then adding the Belle Saison yeast

Not surprised that the alpha amylase didn't do anything, but how did you pitch the Belle Saison? You've got a very inhospitable environment there. It's not going to be easy for any yeast to establish a foothold.

 

[mac_1103]

Add your marshmallow extract, cacao, vanilla, whatever you see fit.
Perhaps put a bottle of Bourbon next to the tap or on the drip tray. Raising the alcohol a tad that way, plus adding its flavor, can make all the difference.

Or maybe make the extracts with REALLY high proof liquor and raise the alcohol that way.

 

[dmtaylor]

Holy moly, that's really stuck. *shrug* I was sure Belle would work. I was wrong.

 

[Northern_Brewer]

I'm assuming there's still a lot of non digestible sugars in there. Any other suggestions? It's really sweet.

Cut it with another wort, give the bugs something a bit easier to digest? Or cut it with another beer that's fully fermented out.

 

[InspectorJon]

I have a imperial stout that turned out sweeter and thicker than I prefer. I have been mixing it 50/50 with another lower gravity stout I made recently. The blended beer is pretty good. Its in bottles so I end up with 22 oz or so pour using two 12 oz bottles. The first one is around 11% and the second is 6.5% so I guess that ends up close to 9% blended. One is enough for me.

It's time to brew some yellow beer but I have to work through all this dark beer I made last fall and winter.

 

[odie]

Well, I made a starter with some saved Belle Saison yeast cake.

Pitched into my RIS and also a Choc PB stout that both finished higher than expected.

The Choc PB has dropped a bit more. Not much but has moved down a couple/few points.

But the RIS will not budge.

Perhaps try some of that Vevik yeast? Or is this thing done?

 

[mac_1103]

Pull out and nuke it from orbit. It's the only way to be sure.

It doesn't look like you're going to get it to do anything else at this point.

 

[odie]

Pull out and nuke it from orbit.

elaborate...nuke it with what? Kevik? White Labs high gravity yeast? Lalvin ec-1118? Lalvin K1V-1116?

Belle didn't appear to have any affect on the RIS. Well how long should I wait on the Belle Saison? It's been almost 2 weeks.

 

[mac_1103]

elaborate...nuke it with what?

Sorry, it was just a joke. I could be wrong, but ISTM that if Belle Saison couldn't touch it in two weeks nothing else will do anything either.

 

[day_trippr]

"Gluke" it...with glucoamylase enzyme. It'll definitely move the needle, but maybe way more than desired...

Cheers!

 

[odie]

Sounds like the thermo-nuclear option. hmm...

I was looking for a tactical nuke... but that seemed to not do much.

 

[mac_1103]

"Gluke" it...with glucoamylase enzyme. It'll definitely move the needle, but maybe way more than desired...

Yeah, if that works you'll wind up with a bone dry 17% ABV beer (OG was 1.130, right?). Definitely global thermonuclear conflict territory.

 

[odie]

Yeah, if that works you'll wind up with a bone dry 17% ABV beer (OG was 1.130, right?). Definitely global thermonuclear conflict territory.

well crap...wanted around 13-14%...but not pure alcohol.

If I did try that stuff I guess I would have to check gravity constantly and cold crash it before it's too late.

 

[InspectorJon]

I think it’s done. From what I understand, a lot of those awesome, expensive aged imperial stouts are blended like wine because each ferment on theses big stouts can end up different. Let it age while you make something else to blend it with.

I have a year old imperial stout that turned out too thick and sweet. It’s pretty awesome blend with a dryer, hoppyer stout I made in February.

 

[InspectorJon]

Cold crashing will not stop Gluco. It will slow it down but won’t stop it. Only heat will stop it. It doesn’t get used up. It just keeps working until there is nothing left to convert.

 

[mac_1103]

Cold crashing will not stop Gluco. It will slow it down but won’t stop it. Only heat will stop it. It doesn’t get used up. It just keeps working until there is nothing left to convert.

Cold crashing will stop the yeast (assuming that the gluco gets the yeast to start up again). But yeah you will lose all of the dextrins so it really won't be an imperial stout anymore.

 

[odie]

well, it was started back in January. Guess it is what it is. I suppose it's time to cold crash and tap.

 

[Bluntsworth]

well crap...wanted around 13-14%...but not pure alcohol.

If I did try that stuff I guess I would have to check gravity constantly and cold crash it before it's too late.

I put some A-Amylase in a stuck Belgian Quad. It works! It took mine from overly sweet 9.8% to a-little-too-sweet 10.5%. SO there were still some unfermented sugars left by the amylase, hence, there is still body to the beer. I bottle aged last month and just cracked one to make sure it's carbonating ok, and it turned out not too sweet and actually quite good overall.

My suggestion: Add a little A-Amylase at a time, and wait. Check the gravity, if it's still too low, add some more and wait some more. I kept mine like this in the fermenter for months without any off flavors from sitting on the yeast too long. But mine is a Belgian, so the esters are kinda desirable.

 

[mac_1103]

I put some A-Amylase in a stuck Belgian Quad. It works! It took mine from overly sweet 9.8% to a-little-too-sweet 10.5%.

I'm not sure we can generalize. Odie has a RIS that's stuck at 10.5 that he's trying to get to 14.

My suggestion: Add a little A-Amylase at a time, and wait. Check the gravity, if it's still too low, add some more and wait some more.

It's an enzyme. It's pretty stable at fermentation temps. You really shouldn't need multiple additions. Usually the problem with enzymes is getting them to stop rather than getting them to keep going.

 

[Bluntsworth]

I'm not sure we can generalize. Odie has a RIS that's stuck at 10.5 that he's trying to get to 14.

It's an enzyme. It's pretty stable at fermentation temps. You really shouldn't need multiple additions. Usually the problem with enzymes is getting them to stop rather than getting them to keep going.

Yeah, mine stopped again. It went slow and steady for about a week then stopped completely again. I ultimately missed my target, but it got me close enough. I mean, I'd personally rather have a dry beer than an overly sweet one, bit that's just my personal preference.

 

[odie]

well, the LHBS had some Amalyze...is that how u spell it?

I added 1/2 teaspoon to each keg. Then I realized that I recently transferred both beers to fresh kegs so I basically moved the beer off the yeast cake from the fermenting keg into a clean keg.

But one beer did appear to move a couple/few points after I added the Belle Saison starter, which was also after the transfer so I guess there is still some yeast in suspension.

Anyway, will sit back and observe at this point. Nothing more can possible be done other than pitching fresh US-05 to replace the yeast cake that is now gone.