Stuck ferment GOSH!

8 days in and my AG stout is stuck at 1.025. It started at 1.55 and I mashed at an average of 153F so I was expecting to get to 1.015 minimum.

7lb 2-row
1lb Flaked Barley
1lb Flaked Oats
1lb Crystal 80
.75 Black Barley
.5 Crystal 120

It tastes pretty good but a little too sweet.

This was the batch that made me think rehydrating dry yeast(Nottingham) is definitely better than dry pitching. I moved the carboy to warmer areas, about 70 ambient and I'm not getting anything.

Repitch? Is this stuff too sweet for even a sweet stout?

dude, stuck even with the aeration system? WTF? Personally a sweet stout is definitely tasty, especially if you have a girl around


Dan

I had this happen to me on a porter. Swirl your carboy around a bit to resuspend the yeast and wait a couple more weeks. It took mine about 6 weeks to finally ferment down to 1.010. This might help.

AleHole said:

I had this happen to me on a porter. Swirl your carboy around a bit to resuspend the yeast and wait a couple more weeks. It took mine about 6 weeks to finally ferment down to 1.010. This might help.

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Yes, I second this recommendation. But do it SLOWLY or your airlock will bubble like mad and almost pop off as CO2 is released from the fermenting wort.

Yeah, it's even more frustrating since I do inject pure O2 and my previous tests have shown it to be effective for more complete fermentations. I knew something was up when it hadn't gotten really going in 12 hours. It was my 11th batch ever but my first where I did not hydrate the dry yeast before pitching. It's easy to blame that one variable but that would be faulty logic. I've got half a pouch of Safale 04 that I'm thinking about rehydrating. I'll drop a cup or so of the wort in to see if there are any more fermentables (can't imagine there isn't). If so, I'll dump that yeast in. I don't think there's that big of a diff between Nottingham and S-04.

This is inspiring me to do another aeration experiment with a few more variables like much lower cell count pitching, short burst of 02, extremely long O2 session (to see if too much is too much), etc.

So I'm 18 days in and the SG is now only down to 1.023. I tried repitching with some S-04 and got nothing out of it. Raised the temps to an even 70F. Nothing. I finally racked to secondary last night and it's not showing any signs of additional fermentation. I'm gonna let it sit for another two weeks to see what happens, but I'm not sure this one is even going to make the keg. Uggh. I mean, I'm not a fan of Stouts in the first place but was hoping to give it some fatherly love and get turned on to them over the course of a 5 gallon batch. If anyone likes sweet stouts, you're welcome to come take a gallon or two off my hands.

Bobby, I think in part your high percentage of Crystal malts contributed to the high FG.

You can add some alpha amylase to it...that'll finish it up. Or beano, essentially the same thing.

Thanks for the tip Dude, I'll give Beano a shot.

zoe... I agree that could be a factor but beersmith put the estimated FG at 1.014 and I'd assume it accounts for the fermentability of all ingredients. I'd be happy with this if it would just get down to the high teens.

2.25 pounds of mainly unfermentable sugars are probably 10-11 points of the sticky. I don't use beersmith, but it seems like many people have been getting odd results with it.

Be warned: Beano can keep the ferment going for a long time.

Those programs do not take into account the lack of fermentabilitiy of crystal malts nor the mash temp when calcualting FG.

You might actually like the taste once it's bottled/kegged.

Just a thought... I'm lookin' at that grain bill and thinkin' theres an awful lot of unfermentable in there. That, with the possibility of a mash temperature discrepancy of two or three degrees...... I dunno, Maybe 25 is as low as it's gonna go.

Not to be depressing or anything....

Hey, ya know, I'm just going to chalk it up to getting frickin creative and trying to craft my own recipe without knowing what the hell I'm doing. I'm kinda disappointed that beersmith wouldn't factor in fermentability of certain malts and mash temps. My trail ran out so I can't test this for sure.

What I'm thinking of doing is making a quick highly fermentable 1 gallon batch by mashing 2-3 pounds of two-row in the high 140's and then bittering it a little more than a pale ale. If I find the stout to be too sweet even after force carbing, I could ditch a gallon and mix in the 1 gallon batch to bump the alcohol and bitterness to balance.

We're learning here.

Bobby_M said:

Hey, ya know, I'm just going to chalk it up to getting frickin creative and trying to craft my own recipe without knowing what the hell I'm doing. I'm kinda disappointed that beersmith wouldn't factor in fermentability of certain malts and mash temps. My trail ran out so I can't test this for sure.

We're learning here.

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That's what I say and was just trying to point that out...hopefully without being critical? Being creative is important, and we learn by doing. I don't think there are exact ways to gauge mash fermentability via software. Two factors. One is that you are dealing with approximate numbers to begin with for pppg, diastatic power, etc. Two the effect of temperature on the mash is tied to diastatic power and some other factors....so it doesn't surprise me that the software isn't spot on. The only really true way you could hope to hit exact consistency is to have an automated mash process and to actually test the dp of all your malts in a batch (or have an analysis sheet from the batch which I have yet to see from my supplier(s)).

Perhaps next time you can bump down the Crytal malts (don't go crazy though, just tweak) and see what happens. Fwiw, my Oatmeal Stout finishes out at 1.020 and it is really nice imo. So, like was mentioned before you should give it some time and see how it pans out after conditioning. Personally I wouldn't mess with it.

None of the programs take it into account (that I'm aware). You can make a recipe with 100% crystal malts and it will estimate that it will ferment just as well as a 100% base malt mash. I think they only take yeast attenuation into account for estimated FG.

Yeah, man, I've never used a program to formulate recipes. And after twenty years of brewing, I'm still tweaking the old favorites and playing around with the basics... This site has so much good info, and so many knowledgeable folks, a guy almost learn to brew just by reading the posts here--- almost. Trial and erro... no, trial and trial. Experience as teacher. OK, I'll quit before I get too weird.

Cheers, everyone -p

What did you have for hops? times? Curious to your ibu's. And is that roast barley or black patent in there? If it's not roast or chocolate malt, then you don't really have a stout.

It will be "sweet" but not as sweet as you think. Not like a lactose stout for sure. Wait till it's carbed. You'll probably be pleasantly surprised. Depending on your bitterness it might balance out ok.

2 tabs of Beano should bring it to about 1.015

Dennys Fine Consumptibles said:

What did you have for hops? times? Curious to your ibu's. And is that roast barley or black patent in there? If it's not roast or chocolate malt, then you don't really have a stout.

It will be "sweet" but not as sweet as you think. Not like a lactose stout for sure. Wait till it's carbed. You'll probably be pleasantly surprised. Depending on your bitterness it might balance out ok.

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I let this stout age a bit in secondary and I finally kegged and carbed it. I never did take a final gravity after all that but I don't suppose it got much lower than 1.022. It's actually pretty damned good! It would have been a little better if it dried out a bit. I suppose a tiny bit more bitter would have also balanced it out.

For hops, I used:
1.00 oz Northern Brewer Leaf [8.50%] (70 min) Hops 27.2 IBU
1.00 oz Tettnang [4.50%] (70 min) Hops 16.0 IBU
1.00 oz Tettnang [4.50%] (5 min) (Aroma Hop-
Steep) Hops -

So that's about 43 IBU. I've been playing around with adding small shots of my IPA to it to see if a little extra bitter would help. Either way, it's drinkable. I'll have to bring some to big brew day to let some of my brew club member weigh in. I don't really have a lot of stout experience.

Finally, from another thread we flushed out that my "black barley" is Briesse's interpretation of a roasted. From their site:

Black Barley
500 Coffee, Intense Bitter, Dry Black Barley provides the color and rich, sharp flavor which is characteristic of Stouts and some Porters.

my First all grains are getting stuck around 1.020 as well (ive been searching for oxygenation sytems this week). After reading this i was just wondering what mash temps have to do with the FG? maybe thats my problem and not the aeration issues.

The mash temps determine which enzymes are working, how long they will work, what kinds of sugar pieces are left... 'tis the essence of AG brewing