Stuck Fermentation on Imperial Stout?

[Bamsdealer]

After 3.5 weeks in the primary, my imperial stout went from 1.110 down to 1.032. Aerated by shaking for several minutes and pitched about 12oz of fresh slurry from a 5% oatmeal stout. Yeast was White Labs 004, Irish Ale. Grain bill was 18lb MO with about 3.5 oz of specialty grain and .5 oz of flaked barley. Also added a pound and a half of light DME and 12 oz corn sugar with 10 min left in the boil. Mash temp was 151.

Is this brew done? Airlock activity stopped completely at 2.5 weeks and everything had dropped out by the time I transferred. I have several packs of dry yeast on hand... Notty, US05 and Champagne yeast. Should I do a starter and pitch more yeast to see if it picks up again? This is by far by biggest beer and I don't have much experience with high gravity brews. I was hoping this would get down to the mid 1.02s anyway...

The oatmeal stout finished a couple points higher than I anticipated, so maybe the irish ale yeast isn't a big attenuater?

 

[beerbeer95648]

Irish is a decent attenuator. It sounds like it is probably done. I am sure a fresh starter could drop it a couple more points as I would expect this to get down to the high 20's. But it is hard to tell at this point. I make it a point to always do a forced fermentation alongside my primary fermentation in order to determine how fermentable my wort is. I cant comment from a place of experience per say as I have never done it. But, I cant think of any potential harm in pitching a healthy starter providing you dont aerate the bulk beer.

 

[MattHollingsworth]

1.032 is probably going to taste very nice for a RIS. It's probably done. If it were my beer, I'd leave it alone. I like my Imperial Stouts with some body. When they ferment too far, all of that roast in combination with a drier beer can make it a bit harsh, IMHO.

I had a RIS a couple of years ago that went from 1.105 down to 1.022, and it was too dry. I added 250 grams of lactose at bottling and now it's perfect.

Anyway, for me, I wouldn't fear that finishing gravity. You should let it sit a bit and then taste it to see if it's got a nice balance. Not every beer should finish dry, IMHO.

As a side note, if you look at Brewing Classic Styles, Jamil's recipe book, he has a RIS recipe by a guy named Mike Riddle. His goes from 1.100 to 1.037 and he states in the book that the beer needs that higher finishing gravity for balance. He's balancing HIS recipe, though, not yours, with his IBUs (77), his hopping schedule, his amount of roast, etc. Your recipe might be better drier than his, I don't know, but I point out this example so you don't needlessly worry and automatically seek out the lowest possible finishing gravity for a beer style that often benefits from NOT finishing dry.

And, I'm brewing another RIS tomorrow, for 12-12-12, a 12% iteration. Cheers!

 

[Bamsdealer]

Thanks for the responses. Good luck on the 12/12/12 RIS.

What scared me was a Belgian Strong Dark Ale I have going. SG was 1085 and I bottled 2 that didn't fit in the secondary. 2 months later and they hadn't carbed using fresh slurry from a second generation yeast. I bottled it today after 3 months in secondary and added a little champagne yeast. I'll be force carbing the RIS, so no concern there... just wanted to be sure the yeast didn't crap out prematurely.

Didn't have a taste of the RIS when I transferred, but I will after it ages a couple months just to make sure it's where I want it. I hopped it pretty aggressively. Considering a little coffee or vanilla if it needs something to help round out the flavors.

 

[MattHollingsworth]

I sample every time I rack. It's a good general practice to see how your beer is progressing.

If you age this RIS, you should make a starter and add that at bottling. Works great. Kai has a spreadsheet for it on this site somewhere.

Thanks on the 12.12.12. Getting started on it now.

 

[brussum]

I don't mean to hijack, but I have a related issue with an oatmeal stout. My 5.5 gal AG recipe included 14.25lb of pale, 2.2lb of roasted, 1lb of chocolate, 1lb of flaked oats, and 2.2lb of malted wheat. The SG was 1.080 and I pitched double dose of White Lab's Dry English Ale yeast (WLP0007). My gravity on Dec 1st was 1.038 and it was the same when I measured it this evening. The room temp is a steady 65F (a little high, I know). It appears to be done, but the final gravity is higher than I had hoped even with the potential nonfermentables in the grain bill. The beer tastes fine and doesn't have any off smells or flavors. Any thoughts or past experience with that particular yeast?

 

[MattHollingsworth]

Double pitched meaning no starter? In my experience, a starter should be made. It's not *just* about increasing the yeast, it's also about waking it up, feeding it and getting it going. NOT making a starter never results in a better beer, IMHO. For me, a lot of times those White Labs yeasts aren't fresh. The date marked is 4 months after packaging. I usually have yeast that's already 2 months old, so for me it's really necessary to make a starter.

That yeast should go much lower than that. Hell, no yeast should stop that high with that OG. You're just past 50% attenuation, which ain't good.

I think you should take steps to pitch more yeast, personally.

And 65 is certainly not on the high side of fermentation for that yeast. You could easily add 4 degrees to that.

 

[RIC0]

I don't mean to hijack, but I have a related issue with an oatmeal stout. My 5.5 gal AG recipe included 14.25lb of pale, 2.2lb of roasted, 1lb of chocolate, 1lb of flaked oats, and 2.2lb of malted wheat. The SG was 1.080 and I pitched double dose of White Lab's Dry English Ale yeast (WLP0007). My gravity on Dec 1st was 1.038 and it was the same when I measured it this evening. The room temp is a steady 65F (a little high, I know). It appears to be done, but the final gravity is higher than I had hoped even with the potential nonfermentables in the grain bill. The beer tastes fine and doesn't have any off smells or flavors. Any thoughts or past experience with that particular yeast?

just bottled my coconut imperial stout with OG 1.086 and FG 1.038 and it was in primary for 2 weeks, repitched the same wyeast in secondary which it sat for 3 weeks. FG was much higher than I wanted but I think it might have all been because of my lack of experience and not using a starter. Will do the SAME exact batch in a few months and use a starter and see what happens.

 

[JonM]

I don't mean to hijack, but I have a related issue with an oatmeal stout. My 5.5 gal AG recipe included 14.25lb of pale, 2.2lb of roasted, 1lb of chocolate, 1lb of flaked oats, and 2.2lb of malted wheat. The SG was 1.080 and I pitched double dose of White Lab's Dry English Ale yeast (WLP0007). My gravity on Dec 1st was 1.038 and it was the same when I measured it this evening. The room temp is a steady 65F (a little high, I know). It appears to be done, but the final gravity is higher than I had hoped even with the potential nonfermentables in the grain bill. The beer tastes fine and doesn't have any off smells or flavors. Any thoughts or past experience with that particular yeast?

If you really want it to go lower, make an average gravity stout and then rack this onto that stout's cake. I've used that to finish up stuck fermentations with great success. (Credit goes to Evan! on HBT for the trick)

 

[brussum]

Coconut imperial stout, huh? Sounds interesting. Can't wait to hear how it turns out.

Thanks for the tip on the starter (that's me being lazy and just pitching). I purchased a couple more vials of the same yeast and will do a starter this time before pitching into the carboy. I'd like to at least get down to the 1.020 range.

 

[RIC0]

Coconut imperial stout, huh? Sounds interesting. Can't wait to hear how it turns out.

Thanks for the tip on the starter (that's me being lazy and just pitching). I purchased a couple more vials of the same yeast and will do a starter this time before pitching into the carboy. I'd like to at least get down to the 1.020 range.

The smell of it was mind blowing good. Deeeeelicious smelling to be honest.

I did taste it and there's no doubt it's an imperial stout but way to early in it's life to be judged on whether it's worth a crap or not. I'm thinking it will be here in a few months.