falling short on final gravity

I'm a newbie brewing extract and grains Imperial stout(trying to achieve something close to Old Rasputin's, from North coast Brewery). My OG was 1.095 and I pitched two vials of wlp001 @ 80deg. at 8pm on 3/30/13 I went to bed and nothing was happening, when I checked at 7:30am the next morn. she was shooting foam through the blow off tube every second. I cleaned the airlock and changed my blowoff container at 8pm 3/31/13 This activity lasted for a couple days then slowed down gradually over the the next few days after that. I let it set in the primary until now, 4/19/13 and I checked the gravity which is only 1.031 I expected closer to 1.023 or 1.024
Is this close enough, I will check the gravity in a couple of days, but I think it is done. From what I have read, I feel I should get my wort of the yeast cake. Is there anything I can do at this point to lower the FG? I Plan on Bottle conditioning for at least 3-4 months, does this sound right? Any input is appreciated.

I've got a RIP sitting in secondary now that finished at 1.030. I want them to finish around there to provide the richness and body I expect in those beers. I have brewed two RIPs and completed one. RIP is one of my holiday beers. I brew them in January with the expectation that they will be at their prime by thanksgiving. I bulk age for four or five months in secondary and bottle condition for the rest. I've not tried bottle conditioning only for four months. That might work. I don't know the yeast you used but I think you got about 72% attenuation. That is probably within the rated capabilities of the yeast and pretty good for a big beer. Cheers.

I'd let it sit on the yeast cake for more time. Big beers tend to need more time in the primary, on the order of a whole month to six weeks or so. An Imperial Porter tends to brew like a stout, and i'm willing to bet since this is your first attempt that it is full of unfermentable sugars. I could verify this if you would post your grain bill (ingredients list). It may or may not be sweet to the taste depending on how much bittering from your bittering hops addition you used, but i'm willing to bet it will be on the malty side. Most porters aren't heavy on the hops to remain true to style.

As to why it stopped and what can be done, it's probably related to any or all of the following:

1) Alcohol level: Yeast can't tolerate high alcohol levels for long.
2) Fermentables: The yeast ran out of fermentable sugars to eat.
3) Pitching Rate: Seems on the light side to me, which causes yeast stress.
4) Oxygen: Yeast burned up the available oxygen too fast, which is important in their reproductive phase.
5) Available Nutrients: The yeast ran out of available nutrients.

Now, as to what to do about it:

A) Nothing: Enjoy your beer even if it is slightly on the malty side.
B) Add nutrients: You can try adding a little servomyces capsule or some yeast nutrient with zinc in it and see if that perks up the yeast.
C) Add yeast: Re-pitch with a more alcohol tolerant strain of yeast like champagne yeast or WLP099.
D) Let it sit: Let it sit another couple of weeks in the primary on the yeast cake.

IMHO, i'd probably pick option B & D, i'd open a capsule of servomyces, sprinkle it into the beer through your airlock hole, re-seal it and let it sit another couple of weeks. Patience is very helpful on bigger beers. They really can't be rushed.

I agree with above, but will also add a couple points...
If this was an extract batch, you may be out of fermentable sugars. You never really know what you'll get from extract. Adding some table sugar may help dry it out a little, as well as boost the missing alcohol counts.
You could also add some high gravity tolerant lager yeast... They will eat more sugar then ale yeast. But I recommend that you make a very large starter to overcome the alcohol already present.

Here is my Grain list, I think I'm gonna let set another couple weeks in the primary I still get a bubble every 65 seconds through my blowoff. I am just a little paranoid from reading the dangers from leaving on the yeast cake too long. Thanks for the input, Sounds like Patience is the hardest thing to learn when Home Brewing.

Russian Imperial Stout Recipe
Extract with Specialty Grains
Batch Size
6 gallons


Malt & Fermentables
% LB OZ °L PPG
55% 10 ~ Briess Traditional Dark LME Boil

2 ~ Chocolate Malt Steep

2 ~ Briess Traditional Dark DME Boil

1 ~ Black Patent Malt Steep

1 ~ Brown Sugar, Dark Boil

1 ~ Crystal 120L Steep

1 ~ Hugh Baird Carastan Malt Steep

~ 4 Roasted Barley Steep

Hops
Usage Time OZ
Icon boil 60 min 3 ¼ Cluster ~ pellet
Icon boil 30 min 2 Centennial ~ pellet
Icon boil 30 min 1 Northern Brewer ~ pellet

Yeast
California Ale (WLP001) 2-vials

Grimstad13 said:

Here is my Grain list, I think I'm gonna let set another couple weeks in the primary I still get a bubble every 65 seconds through my blowoff. I am just a little paranoid from reading the dangers from leaving on the yeast cake too long. Thanks for the input, Sounds like Patience is the hardest thing to learn when Home Brewing.

Russian Imperial Stout Recipe
Extract with Specialty Grains
Batch Size
6 gallons


Malt & Fermentables
% LB OZ °L PPG
55% 10 ~ Briess Traditional Dark LME Boil

2 ~ Chocolate Malt Steep

2 ~ Briess Traditional Dark DME Boil

1 ~ Black Patent Malt Steep

1 ~ Brown Sugar, Dark Boil

1 ~ Crystal 120L Steep

1 ~ Hugh Baird Carastan Malt Steep

~ 4 Roasted Barley Steep

Hops
Usage Time OZ
Icon boil 60 min 3 ¼ Cluster ~ pellet
Icon boil 30 min 2 Centennial ~ pellet
Icon boil 30 min 1 Northern Brewer ~ pellet

Yeast
California Ale (WLP001) 2-vials

Click to expand...

That's not a very fermentable wort. It's only 55% LME with the rest less fermentable specialty grains, plus the LME was dark LME which is not very fermentable. With an OG of 1.095, and only two vials of yeast, it was also underpitched.

At 1.030, I'd say it's as done as it's ever going to be.