Stalled fermentation in my R.I.S

So I have a stalled fermentation in my 10 gallon batch on Russian Imperial. I brewed my stout about 10 days ago and O.G. came out to 1.096. I checked it after 5 days and the gravity had fallen to 1.042. I began warming up the fermenter to keep things moving but, unfortunately, my most recent gravity reading is still at 1.042 and fermentation activity has already dropped off significantly. I’m assuming i’ll have to pitch more yeast.

My question is this: If I have to pitch more yeast, should I prepare a starter again and pitch at a higher temp. (70F) or should I just pitch a smack pack into the fermenter now that the gravity is down to 1.042? I’d really hate to toss 10 gallons of expensive beer that never finished.

P.S. the yeast strain was Neobrittania which, I understand, is rather alcohol tollerant so I’m at a loss as to how it stalled out. A step starter using Mr. Malty and was used for proper pitching rates so that’s not the problem. I do ferment rather cool (64-66F) so i’m wondering if that might be my problem.

Any help would be appreciated.

Have you roused the yeast at the warmer temp?

I’ve tried rousing the yeast by increasing the temperature into the 70’s but nothing more. Should I agitate the fermenter to get them back into suspension?

I use a long-handled spoon to scrape the yeast up off the bottom while gently stirring.

Good idea. I’ll do that. In case I can’t get my fermentation to start again, would you recommend pitching another smack pack directly or making another small starter to pitch actively fermenting yeast? Hopefully, it doesn’t come to that but it would be good to know.

Thanks a bunch for your help as usual, Shade.

If rousing the yeast and the warmer temp doesn’t work, I would make a small starter and pitch when very active.

Or you could pitch some rehydrated US-05.

If the beer is stuck while sitting on a cake, and rousing and warming don’t work, then I doubt you’ll get much traction pitching a couple packs of US-05 or even a small starter. Best bet would be to make a batch of a low-gravity, neutral beer with US-05 or WLP007 or WY1728 (or some other attenuative yeast, but these work well for me) that will ferment out in a week and then pitch the RIS on top of that cake.

This. Your RIS is fine sitting there while you make the new beer… plus you get more beer to drink. I’ve used this method on two strong Belgians that lagged with success.

Are you using a hydrometer or refractometer for your readings?

[quote=“Nighthawk”]Are you using a hydrometer or refractometer for your readings?[/quote]I’m just so used to the refractometer I often forget to ask this question. :wink:

I’m baffled why I didn’t ask this question on Monday. :oops:

Assuming the OP is using a refractometer for the “post fermentation” reading.

An OG of 1.096 and a current brix of 10.47 (1.048) give a SG reading of 1.008 adjusted for the alcohol content.

I’m using a hydrometer. Aware of the effects of alcohol on the refrac.