I've got an imperial stout with OG 1.118 in primary. Its a partial mash with about 40% of fermentables coming from extract/sugar. I added yeast nutrient at the end of the boil. I aerated before pitching, at pitching, and 8 hours post pitching. I pitched 3 rehydrated packets of Nottingham ale yeast, fermented at 64 degrees for the first day, 66 degrees days 2-4, then 68 degrees days 5-7. Now on day 7 I took a SG reading, which was 1.036. 67% attenuation. My goal is 1.028. Should I just let this go another 2 weeks and see what happens or should I try to unstuck it. My thought is to swirl up the yeast into suspension with a sanitized stirrer and increase temperature to 70 or 72 for 2 weeks.
Fermentation stuck? Bother with it?
- Thread starter mcleanmj
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Read you 5x5.
Definitely give that big beer more time, a second week at least...
Cheers!
Definitely give that big beer more time, a second week at least...
Cheers!
mcleanmj
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Thanks! You don't think its worth rousing the yeast? I'm planning to leave it 3 weeks in primary, but I'm trying to decide if I should rouse the yeast or not. I'm planning to raise the temperature to 70 degrees for the remainder either way.
jrgtr42
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Walk away from the fermenter. Give it time. A big beer like that will take longer than a regular pale ale.
Rousing won't hurt as long as it doesn't pull a lot of O2 into the fermenter.
And iirc that strain has a recommended run range that tops out at 70-72°F, and especially this far into fermentation I don't think that would hurt, either...
Cheers!
And iirc that strain has a recommended run range that tops out at 70-72°F, and especially this far into fermentation I don't think that would hurt, either...
Cheers!
VikeMan
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Where did the goal of 1.028 come from?
mcleanmj
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Expected FG with 75% attenuation via Brewfather
VikeMan
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I don't think Brewfather takes grain bill into consideration when predicting attenuation, which can make a big difference, especially when there are lots of dark/specialty malts. If you want to post your grain bill, mash temp, and mash length, I'd be happy to run it through BrewCipher and see what it thinks.
ETA: Beersmith also does not consider grain when predicting attenuation.
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nothing really usefull, but what are you testing the FG with?
edit: and with a OG of 1.118, i bet adding gluco wouldn't finish it dry.....but get it down lower....
edit #2: beersmith says at 1.118 OG, and a FG of 1.020 it would be 13% ABV, which would probably stop the yeast there....
edit: and with a OG of 1.118, i bet adding gluco wouldn't finish it dry.....but get it down lower....
edit #2: beersmith says at 1.118 OG, and a FG of 1.020 it would be 13% ABV, which would probably stop the yeast there....
mcleanmj
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Thanks for the suggestion! I was not previously familiar with BrewCipher but I downloaded it and put in the beer information. It also estimated FG of 1.028. BeerCipher is great, I will definitely use it in the fufure.
I will warm up the fermenter to 70 and check the gravity again in two weeks. I'm hopeful for at least low 70s attenuation.
mcleanmj
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Hi, I tested it with a regular hydrometer. Then I drank the 4 oz sample, which did show great potential and was not overly sweet.
mcleanmj
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Much needed advice! Thanks!
Craiginthecorn
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Brewfather added fermentability % in August 2018.That was unexpected...
Cheers!
schmurf
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I can't say for sure but I've been under the impression brewfather accounts for the grain bill when it calculate the attenuation.
VikeMan
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Easy way to find out. Take a recipe that's 100% pilsner malt, with an OG of exactly 1.050 (for example). See what FG it predicts. Replace the Pilsner with Roasted Barley and scale it so that OG is exactly 1.050. See if the predicted FG is now higher, or the same as with Pilsner.
9 out of 10 Beersmith users (ok, I made up that stat) swear that Beersmith takes grain bill into account, until they test it. (It doesn't.) So, if you are a Brewfather user, could you test this and report the result? If you can do that, Thanks in advance!
ETA: I just got curious enough to test it myself. BrewFather predicts the same attenuation % for any two grains you care to try.
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schmurf
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Tested... I got 1.006 vs 1.044, using US-05
VikeMan
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Are you confirming that it was the same with both grain types?
schmurf
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I attach pics instead..
VikeMan
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So, I just now did 100% Pilsner Viking, OG of 1.050, 65C for 60 for 10, US-05, and got an FG of 1.009.
Then I removed the pilsner malt, replaced it with with Briess Roasted Barley, scaled to 1.050, and got an FG of 1.009.
And, nothing else I do to the grain bill, as long as I scale it to 1.050, changes the predicted FG of 1.009.
I am using the web app. Are there different formulae for different platforms?
schmurf
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That's odd, I created two recipes but tried now, as you did, changed the grain on the same recipe. I got same result as I did previously. I'm using the paid version of the app.
VikeMan
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Perhaps it's a premium feature, which would be good (for subscribers) but not good for test drivers.
ETA: Ok, I figured it out. You have to go into settings and set Final Gravity to "Advanced." (I don't know what happens after 30 days.)
But congrats to Brewfather for incorporating this logic! This was the reason I created the first version of BrewCipher back in 2013, i.e. nobody was doing this.
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