Attempted Imperial Stout - Stuck Fermentation?

[Someguybrewing]

So I attempted an Imperial Stout. Shot for the low side of the style. Some notes: I BIAB. Generally get 60% BH Efficiency (its low but consistent give or take 1%, so for now due to limitations I'm ok with it).
Recipe:
1 Gallon Batch
2.75# - 2-Row
5 oz. - Pale Chocolate
5 oz. - Coffee Malt
3 oz. - Crystal 75L
2 oz. - Carafa II
2 oz. - Roasted Barley
2 oz. - Carapils (probably didn't need this but trying to use it up)

7 grams - Warrior (15AA) - FWH
6 gram - East Kent Goldings (5AA) - 20 Min
6 gram - EKG (5AA) - 7 Min

Safale 05 - 3/4 of Packet ( I did not rehydrate. I know I should and will in the future but did not for this batch)

Mash Temp: 155-156 degrees

Fermented @ 62 degrees

OG - 1.083

?FG? - @ 2 1/2 weeks = 1.036

At this point I thought "What the Hell?". Did a little reading online about stuck fermentation. Under-pitching seemed to be most thought of reason. Don't think that was my problem, if anything I over-pitched. Some people suggested gently rocking the carboy a few times and raising the fermentation temperature up a couple degrees each day. I tried this. I rocked the carboy and raised temp by 2 degrees each day until I got to 68 degrees. I let it sit at 68 for 4 days now. Its been 1 week since first FG reading and it is still 1.036 as of last night.

So my questions are as follows:
Did I screw this up somehow? What did I do wrong?
Is it Stuck? Is it done?
If I bottle it will I have potential bottle bombs on my hands?
Is there a way to fix it?

The hydrometer sample actually taste really good! Nice chocolate and coffee flavors, a little roastyness, slightly bitter at the end, and the slightest alcohol taste...YUM.

 

[freisste]

That is a relatively high mash temp, so it will result in less-fermentable wort. Plus you had a decent amount of crystal/roast, so that will add some unfermentables. I'm not sure your fermentation is stuck - it may just be done.

Have you checked your thermometer to make sure it is accurate? At 155-156, single degrees can have a big impact.

 

[Natdavis777]

I agree with freisste. You are most likely @ FG. Next time I would aim for a 150F mash temp. Maybe try it without the coffee malt and add that 5oz to the 2 row. Roasted barley lends a good coffee aroma/flavor. That way the 2 row will give you more fermentables.

Are you a fan of sour beers? If so, you could always pitch a packet of Roselare Blend and let it ride out for 6-8 months. That is plenty of sugar for the bacteria. I am going to do a tart of darkness clone and mash high, use a sacc yeast, hopefully hit arount 1030, and let bacteria eat the rest to sour. Just a thought though.

 

[Someguybrewing]

freisste & Natdavis777: Thanks for taking the time to respond. I guess my grain bill was a little high on the specialty malts and I mashed too high. Live and learn right! After a little reading most people seem to mash a beer like this between 150 - 152 so I'll go that route next time. I guess I'll have to settle for a regular old Stout and bottle it up.

freisste: Thermometer is pretty accurate. The temperature fluctuation is from me trying to maintain 155. Sometimes adding a tiny bit of heat would jump it to 156 (never above though). Not sure how much actual mash time was spent in 155 and how much at 156. Got to tighten up my control there.

Natdavis: I actually really like sours but I have a small fermentation chamber that only fits either 2 one gallon carboys or 2 two and half gallon fermentors (no interchanging the combo) and I don't want to tie up my fridge that long. Definitely something I've looked into doing in the future though.

Thanks again guys for your help, It's much appreciated!

 

[GuldTuborg]

If you want to sour this, there's no need for a fridge. Just let it ride at room temps. Jolly Pumpkin dregs work great for this kind of thing.

But, if it tastes good, why mess with it?

 

[thegreatmaibockaddict]

You throw in a souring agent be prepared to throw out the equipment that you had used as the sourness may be impossible to completely remove.

The beer is actually likely done. The test will be: will it carbonate in the bottle. If so, it is done.

 

[GuldTuborg]

The beer is actually likely done. The test will be: will it carbonate in the bottle. If so, it is done.

Why is that a good test? I can think of two as to why it's bad. If it is stuck, it could still carbonate in the bottle, and OP won't get any indication of what the problem was until it's too late.

I'd at least try to rouse the yeast some and up the temps. Yes, it's a high gravity, 30% specialty malt beer that was mashed high, but I'd still expect more than 55% AA. Or rather, I'd want to play it safe and take a few basic steps to make sure.

 

[Natdavis777]

You throw in a souring agent be prepared to throw out the equipment that you had used as the sourness may be impossible to completely remove.

The beer is actually likely done. The test will be: will it carbonate in the bottle. If so, it is done.

You do not have to completely disregard the equipment used to sour the beer, just keep it and dedicate it to sour styles. I have 3 fermenters that I used for sours, and that is all.

Also, as stated above, if you did so the sour route, there is no need to temp control it. Room temp is fine. Its the bacteria, not yeast, that will consume the remaining sugar, and they arent picky like sacc yeast.

 

[Someguybrewing]

Well I tried to get the yeast working again with some more gentle rocking and raising the temps a bit...no movement in hydrometer. I am assuming it's done, and I'll lower the specialty malts and mash temps next time.

Good to know that I don't need to maintain temp control if I ever go the sour route (which I probably will)! Thanks for the info guys!

Just as a precaution I lined my storage box with trash bags in case by chance ferm was stuck and bottling kicks things into gear creating bottle bombs. And as an extra precaution when I finally do open one (probably sometime in October), I'll make sure to do it over the sink

Again thanks everyone for the help and info!!!

 

[Inkleg]

Good to see you here SGB.

Like the others said, room temp for aging a sour is fine. Try to find a room with stable temperature. I have mine in a upstairs bedroom with the window blacked out. Cause it's all about the beer.