Russian imperial stout

So i just brewed a russian imperial stout

76% 24 0 Golden Promise 32 2 ~
10% 3 0 Carafa I 32 337 ~
6% 2 0 Crystal 120L 33 120 ~
5% 1 8 Crystal 80L 33 80 ~
3% 1 0 Roasted Barley 25 300 ~
31 8
Batch size: 10.0 gallons
Original Gravity
1.071 measured
(1.078 estimated)

Mash Efficiency
71% measured
(75% used for O.G. estimate)
hops
USE TIME OZ VARIETY FORM AA
boil 90 mins 3.0 Zeus leaf 14.0
boil 60 mins 4.0 Cascade leaf 5.5
boil 60 mins 4.0 Cascade leaf 5.5

So i used my keggle for the first time as my mash tun, i heated it up to the strike temp (well about it, i hit 167) Then i stirred in all my grain and stirred it around for a while. I completely forgot to check my temps and just left it to mash, checked it after 60 minutes and the mash temp was litterally still 167. . . I kinda freaked but just stuck to my plan, did a single infusion mash of 3 gal i believe at about 175 ish. We finished and checked gravity which was at 1.071, this came to be a 71% efficiency. We tried the wort and it was quite bitter, which i am hoping is because of the large amount of hops. It didnt seem hop bitter, i was assuming it was bitter because of my mash temp? Would my efficiency still be the same if my sugars didnt convert? Any shed light would be awesome! Other than that im letting it ferment and then going from there.

Yea that's quite a bit of bittering hops. There's literally no aroma hops in there, it's all bittering. So that's where the bitter flavor has come from I believe. What kind of yeast are you using? You may want to try Wyeast 1084 Irish Ale. It might be capable of eating more of the fermentables and busting down your gravity more. There's quite a bit of dark malt too, so that might not be helping the case any.

Ya i used an irish in one carboy as well as a british in the other, its a friends recipe he has done it around 10 times and it was delicious. I just wasnt sure if my mash temp was just much to high or if im still below 170 i can be fine

If your strike water was 167 and you added a little over 30lbs of grain, it should have definitely dropped it below 167. How did you take your temps, and I'm assuming you weren't heating the mash at all during the 60 min?

If you actually did mash at 167, you're going to have a very unfermentable wort. I've never mashed that high, but I would think your efficiency would still look the same (maybe better since its warmer), but you've denatured a lot of the amylase (beta?) that works at lower temps. The wiki article on mashing says you can expect about 55% attenuation from a mash that high. Check your technique first and make sure you actually mashed that high, but you may want to consider some amylase to bring it down a little, or some sugar to up the OG and dry it out a bit.

Didn't hear during at all. I am using a thermometer that I toss in during the mash, the damn thing didn't budge. Is it even worth keeping the batch? Kinda sucks, I guess I will heat my keggle to like 156 to get a 154 mash temp next time

if you can't reach the attenuation you want, you can always buy some amylase enzyme at your LHBS. it'll break down some of the unfermentable sugars and get you closer to where you expected.

if you're sugars didnt convert your efficiency would be shot, unless you sparged the crap out of it and had an incredibly high lautering efficiency. @167F alpha amylase is still alive n well tho so thats not an issue.