RIS help

[prrriiide]

I brewed a 10 gal RIS (my 1st) on 11/30. OG was 1.095, expected finish was 1.021. It's at 1.031 and VERY sweet.

Grain bill:

40# 2-row
5# roasted barley
1# black patent
1# crystal 60
1# chocolate malt
9.6 oz flaked oats
8 oz special b

Held mash at 157* for 75 min, mashed out/sparged at 168* then standard 60 min. boil. Pitched 2 half gallon starters with a total of 4 vials of WLP050 Tennessee Whiskey Yeast into right at 10 gallons of 75* wort. Everything went exactly by the numbers. Yeast took off like a volcano after about 4-6 hours and went nuts for 3 days. Fermented at 73* for 10 days, then dropped temp to 68*. White Labs says the optimum temp on this yeast is 70-75*.

It's VERY sweet, but with a nice roastiness to it. If I can get some of the sweetness down I think it will be outstanding.

Does this bad boy just need more time to finish lower? Are there too many unfermentables in it to go much lower? Would a re-pitch of something that attenuates well help out? It's still in the buckets on the 050 yeast cake. Temp control isn't an issue, so i can pitch at any temp for a re-pitch.

I need that last 10 points, it's at 8.25%. If I get the last 10 points it gets it to 9.5%.

Thanks!

 

[sweetcell]

i've never heard of using only whiskey yeast in a beer. it is able to munch though complex malt sugars?

if you ferment a beer with a wine yeast, you'll end up with a sweet beer because wine yeast can't digest complex sugars like brewers yeast can (and wort contains both simple and complex sugars). could something similar be the case with whiskey yeast?

the way that i've heard of whiskey yeast being used in the past is as a secondary yeast. a regular ale yeast is used for primary fermentation, then activated whiskey is added to ferment simple sugar additions. ale yeast does the first 10% abv (or so), craps out, then whiskey yeast + sugar are used to get to ridiculousness.

 

[duboman]

I have no knowledge of whiskey yeast at all but with yeast in general going from 73-68 implies the yeast got cold and dropped.

Coupled with the recommended range I would say warm them back up and give them some rousing and they'll get back to work

 

[Sir-Hops-A-Lot]

I haven't had this situation before but I think it's called "Stuck Fermentation."
I would move the carboy back to warmer temps and give it a gentle shake. Then if nothing happened I would consider a yeast that attenuates further or a product called a yeast energizer that is said to help get past a stuck fermentation (according to the owner of my LBS).

 

[dpatrickv]

Personally, I would have pitched 1056 and not the whiskey yeast. It sounds like you have a stuck fermentation though as that yeast should attenuate 75-80%. 1.031 is still too high, my 1.090 RIS finished out at 1.017 with 1056.


Also of note....Optimum ferm temp for that yeast is 75-79°F. I would raise the temp and give the bucket a small swirl to rouse the yeast. http://www.whitelabs.com/yeast/wlp050-tennessee-whiskey-yeast

 

[peterj]

This is not a stuck fermentation. That beer is done. Personally I'm really surprised you were able to get the FG that low with a mash temp of 157F and that many specialty malts. I've never used whiskey yeast either, but apparently it can do pretty good work.

 

[dpatrickv]

This is not a stuck fermentation. That beer is done. Personally I'm really surprised you were able to get the FG that low with a mash temp of 157F and that many specialty malts. I've never used whiskey yeast either, but apparently it can do pretty good work.

I disagree. My RIS had ~17% specialty malts, mashed at 156 and finished at 1.017(OG of 1.090).

The optimal ferm temp for that yeast was 75-79, he wasn't even at the low end of that at the hottest temp he fermented at.

That beer should be able to get down to 1.023-1.025.

 

[peterj]

I disagree. My RIS had ~17% specialty malts, mashed at 156 and finished at 1.017(OG of 1.090).

The optimal ferm temp for that yeast was 75-79, he wasn't even at the low end of that at the hottest temp he fermented at.

That beer should be able to get down to 1.023-1.025.

Wow, that's really good attenuation! What yeast did you use? I just bottled an RIS with an OG of 1.099 that only got down to 1.032. I mashed at 154 but I did have ~22% specialty grains. I pitched Nottingham around 62F and raised the temp as fermentation started to slow. If I were to brew the beer the OP brewed on my system, I wouldn't expect the FG to get any lower than 1.031.

EDIT: Also, did you have any simple sugar in your recipe? 81% attenuation seems crazy to me for such a high mash temp!

EDIT #2: Whoops, I just saw that you used 1056.

 

[dpatrickv]

Wow, that's really good attenuation! What yeast did you use? I just bottled an RIS with an OG of 1.099 that only got down to 1.032. I mashed at 154 but I did have ~22% specialty grains. I pitched Nottingham around 62F and raised the temp as fermentation started to slow. If I were to brew the beer the OP brewed on my system, I wouldn't expect the FG to get any lower than 1.031.

EDIT: Also, did you have any simple sugar in your recipe? 81% attenuation seems crazy to me for such a high mash temp!

EDIT #2: Whoops, I just saw that you used 1056.

I used a fairly large recently rinsed pitch of 1056 and fermented right at 68-70. My recipe called for an FG of 1.023 but that was with an OG of 1.094.

Also, there were no simple sugars added.

 

[Trox]

I would get that yeast back into the high end of its optimal range (74-75F) and rouse it gently to see if it will get back to work finishing up.

 

[prrriiide]

Thanks for the replies!

Would anyone recommend pitching a dose of 1056 or maybe s-05 or Notty? Or am I likely to just be wasting the yeast?

 

[peterj]

Thanks for the replies!

Would anyone recommend pitching a dose of 1056 or maybe s-05 or Notty? Or am I likely to just be wasting the yeast?

I know you really want the FG to go lower, but I really think it's done. I just don't think there's any more fermentable sugar in there. So I wouldn't waste any money on trying to restart a "stuck" fermentation that is probably just done fermenting. If I were you though, I would just raise the temperature and swirl some of the yeast that's already in there back into solution to see if maybe you can get it down a couple more points. It won't hurt (or cost) anything to try that. Good luck!

 

[dpatrickv]

Thanks for the replies!

Would anyone recommend pitching a dose of 1056 or maybe s-05 or Notty? Or am I likely to just be wasting the yeast?

Personally, I think you need to raise the temp to 76-78, gently rouse the yeast and leave it for another week or so. It can't hurt it, and technically you never fermented it in the yeasts optimal range.

 

[sweetcell]

Would anyone recommend pitching a dose of 1056 or maybe s-05 or Notty? Or am I likely to just be wasting the yeast?

if you pitch new yeast, you're going to need to get it active. you can't just pitch a vial or the dry yeast directly in there, you're at 8% abv - that will shock the yeast and they'll likely go dormant. you need to make a starter, let it run its course and pitch shortly after high krausen.

 

[Trox]

Yeah don't bother pitching any new yeast just warn the beer up and gently swirl to rouse the yeast already in there and let it go for about another week and see where your FG is at.

 

[Sir-Hops-A-Lot]

Recipe for RIS bottle bombs:
Bottle with some dextrose, have the whiskey yeast come to life again and convert both the dextrose and some more of the wort into alcohol and C02.
Give to annoying in-laws for Christmas gifts.
BOOM!
I like the idea of making a little starter with a neutral yeast (ex. S-05)
Pitch it with the carboy at a warm temp.

 

[Sir-Hops-A-Lot]

If you go with the bottle bomb method you should use the name:
October Revolution Russian Proletariat Stout

 

[sweetcell]

"Molotov Stout"

 

[Sir-Hops-A-Lot]

I found this information for helping with stuck fermentation:
https://www.homebrewtalk.com/f13/psa-foolproof-stuck-ferment-fixer-72072/

 

[Exportjo]

You can blend it with Nottingham, but it may dry it out past your target...