High gravity RIS is stuck

[AbacusBrewingCo]

It looks like my Russian Imperial Stout, OG 1.097, is stuck at 1.033 (target FG 1.022) I pitched two packs of Wyeast 1028 London ale. It's been about 11 days, and fermentation has been quiet for the last 2 or 3. I'll check gravity again in a few days in case it's still going, but if it's stuck, what should I do to get it to finish out? Even though I'm not sure if it is actually stuck, I might as well buy what I'll need now so it arrives by the time I'm sure.

[spiderwrangler]

What's your temp?

Attenuation on that yeast should be able to get you down farther, you're around 65% attenuated right now.

Also... underpitched by half according to Mr. Malty. Not sayin', just sayin'.

[MaltySmoOTH]

Wyeast lists the London ale yeast as attenuating 73-77%, I've always wondered, is this apparent attenuation or actual attenuation?

[AbacusBrewingCo]

Wyeast lists the London ale yeast as attenuating 73-77%, I've always wondered, is this apparent attenuation or actual attenuation?

is the math on attenuation simple enough to say that a 1.097 OG wort, with 77% actual attenuation will go down to 1.022? (0.77 x 97 points = 74.7 points, 97-74.4 = 22.6, or 1.0226)

also, still hoping for some info on what I should do if my fermentation is in fact stuck! it was recommended to me that i use dry champagne yeast mixed with a few oz of water, is that ideal or is there something better i can do?

[spiderwrangler]

also, still hoping for some info

I'm still hoping it's cold and warming it up a bit and swirling it will kick it back into gear...

[BDawg]

What temp is it at?

[AbacusBrewingCo]

68 degF and hasn't been below that since pitching, may have gotten up to 70 but i doubt much time spent above 68. should i get it a bit warmer than that at this point?

[BDawg]

68 should be plenty for that yeast, but it won't hurt if you get it up to 70 to 72.
I'd get a pack of Nottingham dry yeast and if you haven't budged gravity by your next reading,
boil up a cup or so of water (no chlorine - bottled is perfect for this) and let it cool back down to 90F.
Rehydrate the dry yeast in that for about 15 mins then pitch.