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Stuck Fermentation with Extract Brew Help-

Hello, I’m pretty new to brewing and just brewed my 4th extract brew a few weeks ago. I brewed a porter using some pieced-together ingredients from some recipes I’ve seen on NB. I added an extra 3lbs of LME to boost the ABV but maintaining some body to it–so its more of an imperial porter, I suppose. I had an OG of 1.074. I used wyeast 1450 - Denny’s Favorite Yeast - pitched it at 70 degrees and shook bucket for several minutes to aerate. It was then placed in basement with ambient temp of 64. I realize in hindsight that I should have used a starter or pitched multiple packets of yeast.
After a little over 2 weeks, i took a reading with hydrometer and gravity was at 1.026. I swirled the fermenter bucket around and was careful not to slosh it and brought it upstairs to second floor with a 70 ambient temp. Checked gravity again 4 days later and still at 1.026. Let it sit another week and no change.
My original plan was to move this over to a secondary and add some toasted coconut and then eventually transfer to a keg. Now I’m stuck and not sure what to do at this point. Should I use some nutrients and/or some dry yeast to see if I can some yeast to finish the job? I just worry about too much exposure to oxygen and also any negative effect on taste. Should I just proceed with my original plan and move to secondary and add the coconut and be done? Any help is appreciated. Hoping to be able to salvage this. Thanks!

It could be done depending upon the ingredients. Did your recipe contain a high percentage of low or
or other unfermentables?

I used Briess Dark LME; Briess Amber LME; and 1lb of Golden Light DME; My steeping grains were 1.25lbs Chocolate; and .75lbs Muntons Caramel 60L.

Under pitching yeast could cause an higher than expected FG. Also, at an ambient temperature of 64 degrees your fermentation temperature probably reached 68-69 degrees. That’s still in the optimum range for that yeast but, warmer fermentation temperature will result in a slightly sweeter, less fermented beer. 1.026 is a little higher than I’d expect but not too much. I’d say move forward with the secondary and the coconut.

I would plan to keep the beer in the primary until you are sure it will not ferment further. Take another large hydrometer sample. Check the SG. Try a force ferment of the sample with proofed active dry bread yeast. If the sample shows signs of an active fermentation pitch US-05 into the primary. Rehydrate a pack of US-05 with a very well aerated 1.040 starter wort with yeast nutrient added. Pitch the US-05 at high krausen. Recheck the SG in another 5 days. Keep the beer at 70°F to 72°F.

Warmer fermentation usually results in higher attenuation.

OP, if the bulk of your fermentable were the Dark and Amber LME then it’s likely done. But as @flars said a quick forced fermentation test will show.

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You said it well… imperial porter… Don’t expect something to close in on a standard brew… But, you didn’t tell us all that you used… Sneezles61

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Briess Dark LME; Briess Amber LME; and .75lbs Muntons Caramel 60L

All of the above contain large amounts of unfermentable sugars. Your fermentation is done. Next time, use more light extract, and less of the above. Also consider adding just plain cane sugar which is 100% fermentable, instead of so much extract that is only about 60% fermentable.

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Thanks everyone for the feedback and the advice. I think it sounds like I need to try a forced fermentation to make sure it’s actually done. Sounds like I’ve got some reading to do tonight to figure out what that entails and what I need to do.
I was curious though about the several comments about fermentation temps. For future reference, for similar beers, should I put it in location with higher temps? I thought I remembered reading about actual inside temps being ~ +4or5 degrees higher than ambient temperature. Should I try to shoot for the higher end of the yeast’s recommended temp? Are those temps listed actual internal temps or ambient?
Sorry for the rookie questions. As soon as I think I figure out one aspect of the process, I find a whole new area that I’m screwing up. At least its fun trying. Thanks again for all the feedback and advice.

I disagree that fermentation temperature has any effect on attenuation. It will attenuate faster at higher temperatures, and slower at lower temperatures, but given enough time at either temperature will still end up at the same point either way. At 64 F ambient, that’s just about perfect, not too hot and not too cold. Don’t mess with it. You did good. It’s just done, that’s all. See my previous comments. Ferm temp affecting attenuation would not be consistent with my experience at all, not with most yeasts anyway – very very few exceptions – maybe Belgians are more fussy, but they are the extreme exception. With 1450, this shouldn’t be an issue at all.

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I agree with @dmtaylo2 that your temps were perfect. Too warm and you’ll start seeing esters and fusel alcohols. You are correct that your fermentation temps will rise 4-5° above ambient so you did good. There is usually a correlation between OG and the levels the temps will climb. I say usually because there are other factors including yeast health, pitch amount, environmental conditions.

Regarding my statement above. I went back to the Brewing Bible (aka John Palmer’s ‘How To Brew’) and found that I was thinking of mash (not fermentation) temperatures affecting fermentability.

@loopie_beer, thanks for making me check! Really.

No worries. Your right about the severe under pitch and could have been a contributing problem.

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