High gravity help...!!

So I brewed up a high-gravity stout 2.5 weeks ago (1.142 OG) that I just did a hydrometer reading on. It's currently at 1.052 which is good but I was hoping it would be further along at this point. Yeast was US-05 (harvested from a previous batch and thrown into a 1/2 gallon starter on a stir plate) and it's been holding steady temps around 65F.

Should I be worried that it's only gotten through 50% of the sugars so far? Unfortunately, I ran out of O2 so the only real oxygenation the wort got pre-fermentation was splashing down through a funnel into my carboy. Is 2.5 weeks too short a time frame to expect this to be getting down to 1.032? Any suggestions appreciated!

Wow! That's big one! I had a RIS that started at 1.101 and only got down to 1.037. Depending on if you used extract or a lot of specialty grains (roasted and black malts especially) there will be a lot of unfermentables left over that raise FG.

Not enough oxygen could definately be an issue. The bigger the beer, the more oxygen needed! Still, i'm not if this would go down to 1.032. It really depends.

If you post the recipe it'll help the folks on here determine whether you're there yet. And mash temp if it wasn't an extract batch.

Sure...recipe is as follows:

16 lbs. 2-row
1.5 lbs. crystal 120
.75 lbs. roasted barley
.75 lbs. chocolate
.75 lbs. black patent
3 lbs. carapils (wanted it nice and thick)

3 oz. chinook 60min
1.5 oz cascade 15min

Mashed at 152 for 60 min
Sparge to get 7.25 gallons (wanted to get as much sugar out of the mash as possible)
120 minute boil....5.25 gallons to fermenter

Added 3 lbs. extra-light DME, 1 lb. honey and 1 lb. treacle with 15 minutes left in the boil

You're already up around 11%abv with ~64% attenuation, and US-05's upper limit is about 12%. I don't know how much further you'll get it without transitioning to a yeast with a really high alcohol tolerance and pitching a big ass starter. To get it down around where you want you'll need close to 80% attenuation and 14% alcohol tolerance.

In my own RIS recipe, I used Wyeast Scottish yeast, which attenuates well and has a tolerance of 12%. It still only got to 63% attenuation, and about 9% abv.

I think in your recipe the dark crystal and treacle raised the FG. Most of all though, as you mentioned, the 3 lbs of carapils. You wanted it nice and thick, you got it!

I think this brew is done fermenting (assuming it didn't ferment too cold). I would say the limiting factors to getting the FG down would have been the 3 lbs of carapils and low oxygenation. 3 lbs is substatial!! I bet this will be a good one though, given some aging.

Thanks for all the suggestions...I'm going to try bringing the temp up for a few days and rouse the yeast a little. From everything else I've read, US-05 can mow through a lot of things and handle a pretty high alcohol load. If I can get 16 more points out of it I'll be happy.

By the way...the gravity sample smelled amazing.

Wow, quite a recipe, and holy cow I still can't get over that OG. I bet it will eventually be nice with aging, even if the FG doesn't drop. The 3 lbs of carapils and the 152 mash temp might be a bit much to overcome. If it doesn't move at all with a bit higher temp, you could pitch a champagne, dry mead, or wine yeast to at least see if anything else in there will ferment out, in case the problem is the alcohol content limits of S-05, but I'm sure you've thought about that already. Good luck!

Without WLP099, champagne yeast, or some wild yeast, I don't see that FG going any lower. There is just way too much unfermentables in that recipe

Ditto on the WLP099. The US-05 has hit the wall. Make a starter as well.

So I've moved my carboy upstairs where the temperature is around 68 and roused the use back into solution. Good news! We've got activity in the airlock again. I might just get that sucker down a bit more. I'll update again in a week.

DNuggs said:

So I've moved my carboy upstairs where the temperature is around 68 and roused the use back into solution. Good news! We've got activity in the airlock again. I might just get that sucker down a bit more. I'll update again in a week.

Click to expand...

That's almost certainly due to just warming it up. The gas in the bucket's headspace will expand as it gets warmer, and CO2 will now be coming out of solution both because of the movement and the higher temperatures. I'd be very surprised if it turns out to be fermenting again.

+1 US-05 is done. Time for a yeast with higher alcohol tolerance.