Here's a recipe from when I was homebrewing (and brewing professionally), my take on Bell's.
Imperial Stout
17 lbs 2 row or pale ale base
1 lb medium crystal
2 lbs roasted barley
1.5 lb chocolate malt
1 lb flaked barley
.5 lb rolled oats
6.6 lb pale malt extract
The two row base should be either English or Candian. The German malts are malted for lagers, and it really hard to not get an American two row or pale ale malt that isn't made by Briess, and they suck.
Thomas Fawcett is a traditional English maltster that floor malts their barley. THey do an absolutely excellent job. I highly reccomend you use all of their specialty malts, especially the roasted barley. They don't make flaked barley or rolled oats, but the subleties with these are much less important.
1 oz Chinook bittering (12ish%)
1 oz Columbus bittering (15ish%)
1 oz Tettenager finishing (5 min before end of boil)
The bittering hops aren't so important, and using Fuggles and Golding would be really nice, especially as the beer ages a little, the soft bitterness of those hops would be really nice, but you'd have to use a whole lot of them and it would be pretty pricy on a beer that's already rather expensive. Just make sure you throw in a bit shy of 30HBU, and don't use Cascade.
One vial White Labs WLP028 Edinburg
One vial WHite Labs WLP004 Irish
The Edinburg yeast is good for big malty beers, but using the Fuller strain WLP002 would be fine too. I don't remember why I used the Irish yeast as well instead of just doubling up. The store might have been out, but the Irish yeast is a bit dry, which isn't unlooked for in a beer that's definitely going to come out sweet.
2 tsp Irish moss
.5 tsp yeast nutrient
Lay the grist in base first, then the roasted barley, base, other specialty, more base, more specialty, more base and so on. Having the roasted barley near the bottom will help you get more colour out of it.
Mash at 148° for one hour.
Vourlof and sparge.
Add extract syrup. Volume should be about 4 gallons. Original gravity should be around 1.140.
Bittering hops at start of boil, boil for one hour. Irish moss goes in 15 min before EOB. There's a whole lot of malt protien in here, hence the 2 tsps of Irish Moss. Finishing hops go in 5 min before EOB. Yeast nutrient goes in whenever the instructions say.
I broke my hydrometer at this point so I don't know what the gravity after the boil was, probably around 1.145 or so. Whatever you get will be fine.
Brewing a beer this strong requires a bit more than the regular measures of aeration, protien break catalyzation, and yeast pitching.
Continue aerating at intervals, say every hour or so for several hours after the wort is cooled and the double portion of yeast is pitched. This is wicked strong, so the extra O2 is important.
Beer should be ready for bottling in ten days or so. Bottle with 1 cup of corn sugar.
Taste in 20 days.
It should look as dark as used motor oil. Very strong roasted barley favour shold dominate with coffee and malt following. Tett aroma should open your eyes but shold not contribute precievably to the flavour. Similar to Bell's Expedition, but bigger, darker, and with a nice Tettenager aroma.
Should yield just shy of 4 gallons. ABV is probably around 12%.
