Imperial Stout Stuck at 1.035!

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maltoftheearth

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I brewed an Imperial Stout two weeks ago, it started at around 1.080 and my Wyeast 1084 Irish Ale took it down to 1.035 and then stopped. Fermented at the low end of the temperature tolerance for the yeast.

Bit of an unusual situation, I brewed about 5.75 gallons and had to distribute the wort into a 6 gallon and a 3 gallon carboy before ferment.

Last night (2 weeks into fermentation) I found out the ferment was stuck (I have seen zero activity in the last few days so I combined the two beers into one vessel and shook the carboy vigorously in the hope of rousing a second fermentation. Left it at room temperature overnight. No such luck.

A friend has some Safale-04, I was thinking of proofing this and then adding to the carboy to try and get this at least down to 1.020. I also have champagne yeast but have tried that in the past with zero success. Any other suggestions? The beer tastes great, just too sweet and unbalanced at 1.035.
 
I'm going to say that shaking vigorously after fermentation has been occurring for 2 plus weeks is a good way to get oxidation....especially since this beer would likely need extended aging.

We also need additional information such as recipe (extract vs all grain) mash temps, did you build a starter for the yeast and how did you originally aerate the wort.
 
Since you have 2 possible issues right now (under-attenuation and oxidation), I'd solve both problems by making a 2 liter starter with a Brett culture, pitch it and forget about it for a few months.

Best of luck.
 
Secondary fermentation on a stout with Brettanomyces can produce some really fantastic sours, but it would need a great deal of time to condition. That said: I don't know that it's terribly necessary. If you're using glass carboys and siphoned from one to the other then the headspace in the carboy likely remained to be CO2, curbing oxidation. What oxygen you did shake into suspension should be cleared out pretty easily with a second fermentation if started soon.

A champagne yeast would likely dry the beer out; I think I'd pitch the US-04 you mentioned.
 
Secondary fermentation on a stout with Brettanomyces can produce some really fantastic sours, but it would need a great deal of time to condition. That said: I don't know that it's terribly necessary. If you're using glass carboys and siphoned from one to the other then the headspace in the carboy likely remained to be CO2, curbing oxidation. What oxygen you did shake into suspension should be cleared out pretty easily with a second fermentation if started soon.

A champagne yeast would likely dry the beer out; I think I'd pitch the US-04 you mentioned.

There are two misconceptions here:

1) Brett doesn't produce "sour" flavors. A tiny bit tart maybe, especially in a big roasty, toasty, chocolatey, hoppy beer like an Imperial Stout but the sour flavors are developed by bacteria (lacto, pedio, acetobacter).

2) Champagne yeast will not do much in the way of attenuating the beer unless there are many simple sugars (fructose, glucose, sucrose) left in the beer which is highly unlikely. Champagne yeast will not metabolize maltose, maltotriose etc. You can try, it may lower it by a few points but, eventually, more attenuation will be needed.
 
The mash temp was around 154F but I have never had this high volume of unfermentables ... I am hoping that is the case, though, and I might try a tiny bit-o-beano. I fail to believe it is alcohol limit as ABV is somewhere around 5% at the moment.
 
The mash temp was around 154F but I have never had this high volume of unfermentables ... I am hoping that is the case, though, and I might try a tiny bit-o-beano. I fail to believe it is alcohol limit as ABV is somewhere around 5% at the moment.

Was FG measured with a hydrometer?

I would go for amylase enzyme over Beano. I'm not sure I would ever be desperate enough to chance Beano.
 
Yes, with a hydrometer. And a taste test confirms it is sweeter than it should be.

I have found several threads from the Northern Brewer forum where brewers have used beano with good results. Its just another tool in the toolbox.
 
Yes, with a hydrometer. And a taste test confirms it is sweeter than it should be.

I have found several threads from the Northern Brewer forum where brewers have used beano with good results. Its just another tool in the toolbox.

Your beer, your call, Beano seems to unpredictable for my taste. Amylase enzyme worked well when I used it.
 
My russian stopped at about 1.032 but was coming down from 1.114 so i still got a good ABV... I started with Nottingham and then pitched in some s-05 after it had crapped out at about 1.048-50.

What is your recipe you used? My estimate was a FG of 1.029 so i was more than happy w .032.
 
To make a big beer attenuate really well, it's almost always a good idea to mash low - like 149 and for more than 60 mins - to give the yeast an easier time chewing through it.

If it hasn't been oxidized, a great thing to do is brew a modest gravity beer in the same kind of style, in this case, maybe a 1.050 OG oatmeal stout, ferment it, rack off its cake, then put the stuck beer on the 1.050 beer's cake. I just sis that with an all Maris Otter barleywine stuck at 1.040. Brewed a simple 1.040 Maris Otter lawnmower beer, put the BW on the cake, and fermentation started right back up. Give it a try.
 
How much yeast did you pitch or how big of a starter??

Might sound silly but I know from experience and many others under pitching leaves the FG higher than you want.

And to add to that once my mistake was done it was done, no getting the FG lower than it was, throw in the towel and drink a good beer just not a high gravity great beer.
 
I just checked my breakfast stout, which started at 1.086 been going for 13 days and it's at 1.026 which is not low enough. Airlock is pretty non active but giving it 2 more weeks before I rack it to secondary, hope it keeps dropping but not holding my breath. DAMIT

I pitched 1.5 packs of rehydrated yeast then 3 days later tossed in the rest of the half pack.
 
So my stout should be around 9.1% it currently sits at 8.1% 3 weeks later.

Is it safe to say it is what it is and leter ride and be happy with what I got or is there any way in hell to get more out of it??

It tastes good and i still have to rack to secondary to add vanilla beans, coffee and chocolate.
 
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