I did some research to find a AB clone recipe a while back, finally got time to find it. I got this first recipe from the homebrew forum on ratebeer.com, the author claims that it is very close, but I have not made this:
13 lbs 2-row
1 lb. Crystal 60-80L
Boil 90 min.
30 HBUs Chinook 90 min.
1 tablet Whirlflock 20 min.
2 oz. Chinook 15 min.
1 oz. Chinook 5 min.
2 oz. Chinook dry hop
Yeast is likely WLP007 Dry English Ale, but I think WLP001 would work fine.
The crystal malt used seems to be a variable worth experimenting with, I have seen it as 60, 80 and 120.
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So, then I located another recipe that seemed more interesting to me, but probably not quite right because I don't believe AB has any Cascade in it. I ended up messing with it, brewing something that came out something like AB but stronger, more complex and, believe it or not, more aggressive. It has 4 different specialty malts and 3 varieties of hops. I copied the original one I found below - my tweaks were to basically replace the Cascade with Centennial and make all the specialty malts 1/2 lb. I also did a partial mash with 3lbs of Marriss Otter 2-row, this brought the OG to 1.094. I have made that version a couple of times with WLP001 and will do it next time as an all-grain. If anyone wants this recipe let me know.
Stone Brewing has never given up this recipe but it has fostered a hundred clone recipes from frustrated brewers attempting to copy it. This recipe is as close as I have found. This wonderful brew possesses myriad great flavors, from an initial malt bite to a wonderful hop aftertaste.
7 lbs Light Malt Extract
2 lbs Dry Light Malt Extract
1 lb Belgian Special-B Malt
1/2 lb Belgian CaraVienne Malt
1/2 lb Belgian CaraMunich Malt
1/2 lb Belgian Biscuit Malt
2 1/2 oz Chinook Hops 30 HBUs(Bittering)60 min
2 oz Columbus Hops (Flavoring) 20 min
2 oz Cascade Hops (Aroma) 2 min
Wyeast British Ale Yeast