The point of the mushrooms (other than thematic) was to add earthiness and maybe umami--lip smacking goodness.
Even though I made some errors, I consider the recipe a fair success--I would make it again.
Below is a one gallon batch. There are some important differences if you make this--my efficiency, in a word, sucks...so I would suggest reducing the pale by 0.5 lb, and the Crystal/Special B by 0.25 lb each. It will be higher ABV, but that works with this theme.
Dwarven Mushroom Stout - Foreign Extra Stout
Batch Size: 1 gallon
Boil Size: 3.364 qt
Boil Time: 60.000 min
Bitterness: 20.2 IBUs (Tinseth)
Color: 90 SRM (Daniels)
Name Type Amount Mashed Late Yield Color
Pale Malt (2 Row) UK Grain 2.000 lb Yes No 78% 3 L
Special B Malt Grain 1.000 lb Yes No 65% 160 L
Caramel/Crystal Malt - 80L Grain 1.000 lb Yes No 74% 80 L
Chocolate Malt (US) Grain 4.000 oz Yes No 60% 350 L
Black (Patent) Malt Grain 2.000 oz Yes No 55% 500 L
Brown Sugar, Dark Sugar 4.173 oz No No 100% 50 L
Total grain: 4.636 lb
Name Alpha Amount Use Time Form IBU
Fuggles 4.5% 0.250 oz Boil 5.000 min Pellet 3.4
Fuggles 4.5% 0.250 oz Boil 60.000 min Pellet 16.9
Name Type Use Amount Time
Mushrooms, Portobello Flavor Boil 8.000 oz 60.000 min
Name Type Form Amount Stage
Coopers Ale Ale Dry 0.247 oz Primary
I am learning here, so will not give the way I did it. Especially since I was seeing if an electric turkey roaster could be used to control the temperature (it can't)...moving on.
You want a high temperature mash, starting at 155, and I would say to move it up into the low 160s for a while to produce even more dextrins.
Follow your usual brewing/mashing procedure--if you are considering making the recipe, I'm assuming you already have your own preferences on how to do things.
Pitch English ale yeast (I used Coopers), and ferment out. My finished gravity was 1.040--sweet (or extremely high in dextrins, I was told). I fermented for about two weeks, then left it in secondary for another two weeks.
Bottle condition for 2.5 units of carbonation.
Thick, almost chewy in body. The flavours are earthy, bitter, chocolate and coffee, and malty sweetness (not necessarily in that order). I enjoyed making it and drinking it, although it's something I could only have one bottle at a time.