1st Imperial stout advice please (now bottled)

[lord groan]

I'm planning on an Imperial stout soon but my malt/hops knowledge is small so I'd appreciate some input from those who've already gone down this route
What i've got to play with:
Grain - Pale, Crystal, Caramalt, Chocolate,Black, Roast Barley, Wheat malt
Hops- Boadicea,Fuggle,Northdown,Target,Golding, WGV, Styrian,Magnum, Willamette and Bramling X

Possible combination?:
Pale 3.5kg
crystal 200g
caramalt 200g
black 50g
chocolate 250
roast barley 500

Magnum 30g
Willamette 20g
Northdown 15g
all in around 10-12l.
Beer engine gives this an SG of 1.094, finishing at 1.034?? and 89 ebu.

Questions
First what do you think?
I'd like the FG much lower, why is it predicted to finish so high?
I've never used Willamette or Magnum so I'm not familiar with these, does the hop profile look ok?
Any and all thoughts and advice very gratefully received

[micmacmoc]

Magnum go nicely in Imp stout, I don't bother with late hops as I like my stouts roasty and strong. I can get my stouts down to about 1020 which is fine, I usually use the yeast collected from a previous, lighter, brew. If this isn't possible pitch a couple of packs or make a yeast starter. I really love imperial stout at the moment, I've made four batches in two months! And just to be sure a coopers twocan stout. That seems a lot of roast barley....even by my standards! I think it may benefit from some sugar to stop it from being too syrupy. Theres people here who know more than me so over to them! Good luck. Stout...mmmmmmmmmmm.

[Rookie]

What yeast are you going to use? I use S-04 in mine and get way lower than 1.034.
Hopwise I'd go with target and goldings.

[lord groan]

I have some SO4, I was going to brew something along the lines of Summer Lightning and then whack the RIS wort onto the yeast cake left over from that

[floydmeddler]

Mash waaaaaaaaaaay 'too' low. Around 60c for a few hours. Even better, over night. Will more than likely raise your grain efficiency too. Winner!

[lord groan]

Nice one floydmeddler, I hadn't thought about mash temp, I usually mash high - 69/70'ish to keep a bit of residual sweetness, but lower makes perfect sense with a heavy brew like this
thanks

[darkonnis]

Be careful with the dark malts. You'll end up with an overpowering charred flavour, I'd reduce the amount of roast from 500 and maybe add some amber and some brown malts, not to mention upping the pale malt slightly.

Whats your expected efficiency? if you usually get 75ish, then I'd expect it to drop down to between 55 and 65. I'd also make sure you give the grains a good squeeze to get more wort out of em, you could also add a little more pale malt after the first mash and make a second, smaller beer (this is known as partigyle brewing)

[lord groan]

Well I've just bottled my RIS, the final recipe was;
Pale 3700g
Crystal 200g
Roast Barley 330g
Chocolate Malt 200g
Caramalt 200g
Black malt 50g
Wheat malt 150g
Hops-30g magnum, 20g willamette at 90 mins, 15g northdown at 20 mins
OG ended up as 1092, FG 1020 fermented using the Safale SO4 yeast cake left after a golden ale was brewed. Fermented at 22-25c (variable due to hot weather) for 3 weeks, although pretty much done after 1 week.
Taster while bottling - wow! licorice followed by coffee with chocolate coming through at the end, still very bitter, quite thick almost syrupy to drink, stronggg.
Can't wait to try the conditioned article, aiming to wait until December!
I'm naming it Black Widow, just got to come up with a bottle label now

[micmacmoc]

Nice one! Bet it does'nt last til xmas! Best get another one on right away!

[floydmeddler]

Cracking name man!

If you can bear it, leave some for Dec 2015 too. Jeeze, it will taste even more incredible then.