Fermentation in an Imperial Stout

[drs650]

Hi fellow beer nerds - question for the group. I brewed an Imperial Stout (attempt to clone Prairie Bomb.) Grain bill was 26 lbs, including 1 lb. of Belgian candi sugar. So there's a *lot* of sugar to eat up. Ended up with a really high starting gravity - OG of 1.112

Because of the large grain bill, I decided to pitch two cans of Imperial Flagship yeast (about 400 Billion cells.) Fermentation literally started within 2 hours, which was awesome and impressive. It's now been exactly two weeks. I checked gravity, and it's at 1.034. So my ABV is already at 10.25%, but I kinda think there's still a ways to go. The bubbler is still bubbling occasionally, maybe every 90 seconds or so, at 14 days in.

I'm planning to rack over to a secondary and add some ingredients (ancho chiles, vanilla bean, cacao nibs, etc.) The beer will have 3 weeks in the secondary.

So my question is, should I leave it in the primary a little longer and let it continue working before racking to secondary? Should I rack to the secondary and count on the yeast in suspension to keep plugging away. Should I pitch *more* yeast? (crazy).

WDYT?

 

[day_trippr]

So that beer is now sitting at ~67% attenuation using a strain advertised for 73-77%.
While I suspect it may be done after 14 days, you might as well let it roll for a few days and take another SG reading.
If it has dropped at all, let it roll another week, otherwise that'll be the time to take stock and decide what to do next...

Cheers!

 

[drs650]

thanks @day_trippr

 

[honkeypot]

I'm in a similar situation. I made a big RIS two weeks ago and the OG was 1.130 but it's been sitting at 1.040 for 7 days. I've been rousing the yeast and even kicked up the temp to about 72 without stimulating any other activity. I thought maybe the yeast (wyeast 1028) couldn't handle the nearly 12% alcohol so in hopes of getting them to chew through a bit more of the sugars yesterday I rehydrated some US05 and tossed it in the fermenter. I was at school and work for 14+ hours yesterday so I wasn't able to watch for any activity but there appears to have been no change. I'll take a gravity reading either tonight or tomorrow morning to see what's up.

 

[honkeypot]

Quick update - a week after adding the yeast gravity is down to 1.036. I don't suspect it'll drop much lower but I'll let her ride a few more days to see how she does.

 

[olotti]

Quick update - a week after adding the yeast gravity is down to 1.036. I don't suspect it'll drop much lower but I'll let her ride a few more days to see how she does.

With all you've done up till now and an og of 1.130 I'd say it done. I leave my big RIS in primary for a month just to make sure it's done and the yeast have had time to clean up. Then I either bottle or move to secondary for adding any adjuncts.

 

[honkeypot]

Surprisingly the gravity dropped to 1.026. Now I'm just praying that the yeast will keep working and clean up any diacetyl they pooped out. Plan to let it sit another week or so and see how it tastes.