Lower Final Gravity after low attenuating yeast

Hey,
I'm brewing the Stone Ruination Clone in this month's issue of BYO. It says it should have OG of 1.072 and FG of 1.012 but the yeast they recommend is WLP002 (I'm using Wyeast 1968, same thing). Anyway, to get those numbers, I would need 82% apparent attenuation and the range for 1968 is 67-71%. The article even mentions it should have a 'dry finish'.

What should I do to get it down to 1.012? Can I pitch a higher attenuating yeast once the primary ferment is done to pull it down a few more points?

FYI, I brewed it last night so I don't know what the FG will be but I'm anticipating that it won't be anywhere close to 1.012. My OG was 1.071. The lowest I expect is 1.020...

My calculations come out to 72 / 4 = 18 at 75% attenuation.

Since you are already at 12 it's drier than the anticipated 67-71% you mention.

Since the majority of the fermentation is complete I would rack to a secondary and place it in another place just a degree or more higher to try to push the yeast, or just forget about it.

homebrewer_99 said:

My calculations come out to 72 / 4 = 18 at 75% attenuation.

Since you are already at 12 it's drier than the anticipated 67-71% you mention.

Since the majority of the fermentation is complete I would rack to a secondary and place it in another place just a degree or more higher to try to push the yeast, or just forget about it.

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Hey, I'm not at 12. I said I'm anticipating 20 at the lowest which is way higher than I want.

I suppose I should just wait and see what it turns out at. I will try raising the temps once the activity dies down though.

Slowly raising the temperature and agitating the fermenter as fermentation slows can both help keep the yeast from quitting. I can't think of anything else you might do post pitching. I'd really like to have that recipe (AG) if you would post it.

Coastarine said:

Slowly raising the temperature and agitating the fermenter as fermentation slows can both help keep the yeast from quitting. I can't think of anything else you might do post pitching. I'd really like to have that recipe (AG) if you would post it.

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Sure, its actually quite simple. I ended up using Nugget instead for the bitter cuz that's what I had.

Stone Ruination IPA Clone
OG=1.072 FG=1.012 IBU=100+ SRM=12 ABV=7.7%

14 lb 2 oz. 2 Row
14 oz. Briess crystal 15 L
36 AAU Magnum (90 mins, 2.25 oz at 16% AA)
16 AAU Centennial (15 mins, 1.5 oz at 10.5% AA)
2 oz Centennial Dry Hops
White Labs WLP002 (or Wyeast 1968)

Mash at 149 for 60 minutes. Boil for 90 minutes. Ferment at 68 degrees.

Yes, ater the fermentation slows down, you can re-pitch with a high-attenuation yeast. Or even rack it and re-pitch. Since the primary yeast will have done most of the fermentation, the finish yeast won't add much, if anything to the flavor.

What would be a good yeast to use for that?

Coastarine said:

What would be a good yeast to use for that?

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Good question. I don't know. I've had good results getting US-05 close to 80% AA, so I may give that a shot. I'm nervous to go to any of the 80+ wine/champagne yeasts. Maybe a yeast expert will chime in with a recommendation.

Just an update on my Ruination clone. It only got down to 1.024 after a couple of weeks, including rousing and raising the temp to 75 degrees.... Today, I added about 1.5 quarts of washed yeast slurry (US-05) and kept it warm. It appears to be doing something but I won't know for sure for a few days. Will let everyone know....

I have had that same problem with recipes - they say to just get to 1.0## FG but the yeast used "at least for me" will never get to that. For instance - I had one call for an FG of 1.008 using American Ale 1056. I can never get it lower then 1.012.

Final Gravity depends on a lot of things, including mash temp, rest time, extract fermentability etc. I never had extract batches finish below 1.014 or so, but with AG, I can routinely get 1.007 or 8 if I mash low enough for long enough. I prefer a drier beer, so that pretty much pushed me to AG.