Restarting big beer fermentation

[Matt3989]

Okay, so I have 5 gallons of RIS OG= 1.095, current SG=1.030. Fermentation has stalled and I haven't been able to get it going again. My solution, which I'd like opinions on, is this:

Dissolve 3lbs of DME into a gallon of water and steep some chocolate malt, aerate that with oxygen and add some wlp090 (the San Diego super yeast). After a couple of hours once the yeast have absorbed some of the o2, adding that all into the RIS.

I mashed at 152 for 2 hours, maybe 4 by the time I got the wort over 168 to stop conversion. So I think there should be enough fermentables to get down to around 1.020, so the 10 points of gravity (to go from 1.030 to 1.020) over the 5 gallons now, plus the 120 points over the one gallon additional, means I should pitch around 170 billion cells.

Does all of that seem correct? Any suggestions? Changes? Experiences?

 

[DocScott]

How long has it been since you pitched? What yeast did you originally pitch?

Your FG will depend on a lot of issues though. 1.030 may be as low as you can go with a bigger beer like this if it has a high percentage of crystal malts or other unfermentables.

Before you repitch, try swirling and warming the fermentor up a bit. If that doesn't work, you can try pitching the WLP090. Making a small starter and pitching at high krausen isn't a bad idea but I don't really see a reason to add the steeping grains or make such a huge starter. Also, aerating the starter probably isn't necessary, assuming you have it on a stir plate or some other way of giving oxygen to it to promote the replication process.

To save you the trouble of all of that, why not just pitch some rehydrated S-05 if you have it lying around? It tends to be pretty alcohol tolerant and attenuates pretty well.

Good luck and let us know how it works out. btw, a RIS at 1.030 may not be too terrible!

 

[BigFloyd]

You're a hair over 68% attenuation. Depending on your recipe and yeast strain, that may be all you're going to get. Have you tried warming it up to 70-72*F and using a sanitized spoon to work the yeast up off the bottom? If not, I'd do that first and then check it again after a week.

Your first solution has a better chance for success if you scale it down to about 1 liter of 1.035 oxygenated starter wort (no chocolate malt needed), let it get going, and pitch into the RIS at high krausen.

Are you checking gravity with a hydrometer or a refractometer? You probably know the issue with that, but just wanted to check that off the list of possibilities.