Bottle stout with high FG (1.027)?

[Vip8888]

I am a new brewer (seven batches so far) and my latest brew is a coffee stout that is currently in the fermenter. When taking gravity readings, fermentation appears to have stopped at 1.027.

Do I still dare bottle the beer, or is this a recipe for a bottle bomb disaster?

Some more background:
I brewed the batch on 28th Nov and got an OG of 1.083, and pitched half a pack of Mangrove Jacks M15 (as I made a half batch). Fermentation was really intense the first few days, and by 1st Dec the SG was down to 1.030.

On 9th Dec it was still stuck at 1.030, so I rehydrated half a left-over pack of Safale S-04 (thinking it might handle the high alcohol volume better) and pitched that. It started fermenting again bringing SG down to 1.027, but it has been stable at this gravity for a week now.

Any thoughts on how to best proceed would be appreciated please. I'm wondering if I perhaps have sugars that won't ferment, or maybe the coffee beans in the fermenter has killed the yeast (as I said, I'm a new brewer ).

For reference, here is the recipe I used:

IBU : 84 (Tinseth)
Colour : 69 EBC
Carbonation : 2.4 CO2-vol
Pre-Boil Gravity : 1.066
Original Gravity : 1.086
Final Gravity : 1.019

Batch Size : 12 L
Boil Size : 16 L
Post-Boil Vol : 13.02 L

Mash Water : 10.95 L
Sparge Water : 7.65 L

Boil Time : 60 min
Total Water : 18.6 L

Brewhouse Efficiency: 80%
Mash Efficiency: 83.3%

Fermentables (4.22 kg)
3.371 kg - Pale Ale 2.2 EBC (80%)
369 g - Crystal 400 127 EBC (8.8%)
211 g - Carafa III (Weyermann) 765 EBC (5%)
160 g - Cane (Beet) Sugar 0 EBC (3.8%)
105 g - chocolade Malt 740 EBC (2.5%)

Hops (63.5 g)
60 min - 15 g - Chinook - 13% (34 IBU)
60 min - 15 g - Columbus - 15% (39 IBU)
15 min - 8 g - Columbus - 15% (10 IBU)
0 min - 17.5 g - Willamette - 5%
0 min - 8 g - Columbus - 15%

Miscellaneous
Boil - 100 g - Honey
20 min - Boil - 200 g - Muscovado Sugar
Primary - 42 g - Coffee beans
Primary - 1.5 items - Vanilla

Yeast
6 g - Mangrove Jack M15
0.5 pkg - Fermentis SafAle English Ale S-04

Mash Profile

64 °C - 90 min - Mash step 1
75 °C - 10 min - Mash Out

Fermentation Profile

19 °C - 14 days - Primary
19 °C - 14 days - Secondary

 

[Erik the Anglophile]

It is probably done.
M15 is known to be an early stopper, and has relatively low alcohol tolerance together with low-ish attenuation in normal gravity beers as it is, I am still pretty new aswell, but have had the same issue with that yeast in an OG 1.064 porter that stopped about 5 points north of what I expected. I would try a strain that has higher alc tolerance and better attenuation capabilities next time I do this recipe. And tone down the sugar a bit maybe in favor of more grains

 

[ReaperOnefour]

I'd say the beer is done. I've never used M15 before, but i use US-05 95% of the time. (which ferments quick & clean.) I always ferment for two weeks, then bottle. I've never had any problems with this approach. It's almost been a month since you brewed it, so i think its ready to bottle. Hope this helps. Welcome to the greatest hobby in the world, & to the forums.

 

[Erik the Anglophile]

And also, about 11 grams of yeast seems a little cheap for 12l of wort of that gravity, I'd add 2 packs just to be sure.

 

[Vip8888]

Thanks for the feedback.

I realise in retrospect that I should have used more yeast, but I'll chalk that down to learning experience.

There has appeared to be a little bit of activity the last couple of days, but I just took another reading and it's still stuck on 1.027. I'm now debating whether it would be worth rehydrating even more yeast and pitch at this stage, or if I should just bottle it. It does taste very nice when taking the samples, so I am inclined to bottling it.