Insanely Big Imperial Stout!

[strange-steve]

I have a couple more brews at the top of my list to get through, but I was thinking it's about time I planned another big stout. And I mean PROPER BIG this time, enough to cause even @dad_of_jon to raise an eyebrow. The following recipe is one I've had for quite a while now, but always been a little scared of it. It's loosely based on Three Floyds Dark Lord, and just look at this ridiculous recipe:

The Mad Russian Imperial Stout

Recipe Specs
----------------
Batch Size (L): 18
Total Grain (kg): 12.3
Total Hops (g): 100
Original Gravity (OG): 1.140
Final Gravity (FG): 1.029
Alcohol by Volume (ABV): 14.5 %
Colour (SRM): 79
Bitterness (IBU): 95
Brewhouse Efficiency (%): 60
Boil Time (Minutes): 120

Grain Bill
----------------
8.0 kg Pale Malt (65%)
1.0 kg Cane Sugar (8%)
1.0 kg Flaked Oats (8%)
0.8 kg Chocolate (6.5%)
0.5 kg Dry Malt Extract - Light (4%)
0.4 kg Roasted Barley (3.5%)
0.3 kg Crystal 120 (2.5%)
0.3 kg Crystal 60 (2.5%)

Hop Bill
----------------
100 g Magnum Pellet (15.3% Alpha) @ 60 Minutes

Misc Bill
----------------
40.0 g Coffee @ 10 Minutes (Boil)
2 g Vanilla @ 3 Days (Secondary)

Single step Infusion at 65°C for 90 Minutes.
Fermented at 19°C with Safale US-05


As you can see this 18L batch has over 10Kg of grain plus 1kg of sugar and 500g of DME! So to make this a bit more manageable I was thinking of splitting the batch into two separate mashes and combining the wort in the kettle.

Has anyone tried anything this big? I know efficiency is going to take a big hit, will I get anywhere close to the OG? Will US-05 even ferment up to 14%, and if not any suggestions??

 

[MrRook]

I'd lose the crystal and maybe the oats.
I've read posts claiming 15% with 05.

 

[Ajhutch]

I’ve got no idea about the mash of a grain bill that big, the combining sounds sensible but however you go about it it’s a seriously concentrated wort. There’s probably no harm with this beer in erring towards a thinner mash and if you collect too much wort just boiling a bit longer.

If you’re worried about yeast capability could you hold the sugar back until later in fermentation and add it with a wine yeast?

 

[ACBEV]

14.5% ----

I've brewed Imperial to 12% a couple of times, my tips are...

Boil longer, so you can have a lower boil gravity and higher OG, this helps with mash efficiency.
and/or only use the first runnings for the Imperial and the second runnings for a low ABV beer (maybe mash twice to get enough wort).
I tend to use two yeast strains - Wyeast Scotttish Ale and Wyeast Belgian Ardennes --- Both go to 12%
Ferment @ 20-22c
On day three in the FV, I tip the whole lot into a second FV. This tends to stop stalling.

 

[IainM]

Crikey! You'd better get the pitch rate right on that beast. Are you considering a two-stage mash?

 

[Zephyr259]

Nice! That's a brave take on. Doing this in the Grainfather is going to be a nightmare. ACBEV is probably on to something with combining the first runnings from 2 mashes, that's a technique suggested for the big 120/- and 140/- beers in the old Scotch Ale book. I'd certainly go for a reiterated mash, that way if it's still short after 2 mashes you could do a third... I'm actually thinking of brewing something similar soon but a couple of percent lower.

I wouldn't boil your coffee, steep it at flameout like your making a coffee or (cold) brew and add later.

I'd be nervous of US-05 getting this done, would you like some kveik? They're meant to be good for mid-teens. I've only gone to 10.5% with Opshaug (and it took 3 weeks...) but @BeerCat has done a few big stouts with Voss. I'm planning on sending you a beer next week anyway so can slip a vial in.

 

[Sadfield]

With the sugar and DME, you are effectively mashing for a c12% beer.

I'd maybe swap flaked oats for malted oats, and not worry about diastatic power, and then do two mashes with little to no sparge. If you are adding DME anyway, having some extra to make up any short fall is no biggy.

My concern would be the sugar being an easy to consume treat for the yeast at the start of fermentation. I'd perhaps do as @Ajhutch suggests and add the sugar later on.

+1 on Scottish yeast.

 

[dad_of_jon]

I have a couple more brews at the top of my list to get through, but I was thinking it's about time I planned another big stout. And I mean PROPER BIG this time, enough to cause even @dad_of_jon to raise an eyebrow. The following recipe is one I've had for quite a while now, but always been a little scared of it. It's loosely based on Three Floyds Dark Lord, and just look at this ridiculous recipe:

The Mad Russian Imperial Stout

Recipe Specs
----------------
Batch Size (L): 18
Total Grain (kg): 12.3
Total Hops (g): 100
Original Gravity (OG): 1.140
Final Gravity (FG): 1.029
Alcohol by Volume (ABV): 14.5 %
Colour (SRM): 79
Bitterness (IBU): 95
Brewhouse Efficiency (%): 60
Boil Time (Minutes): 120

Grain Bill
----------------
8.0 kg Pale Malt (65%)
1.0 kg Cane Sugar (8%)
1.0 kg Flaked Oats (8%)
0.8 kg Chocolate (6.5%)
0.5 kg Dry Malt Extract - Light (4%)
0.4 kg Roasted Barley (3.5%)
0.3 kg Crystal 120 (2.5%)
0.3 kg Crystal 60 (2.5%)

Hop Bill
----------------
100 g Magnum Pellet (15.3% Alpha) @ 60 Minutes

Misc Bill
----------------
40.0 g Coffee @ 10 Minutes (Boil)
2 g Vanilla @ 3 Days (Secondary)

Single step Infusion at 65°C for 90 Minutes.
Fermented at 19°C with Safale US-05


As you can see this 18L batch has over 10Kg of grain plus 1kg of sugar and 500g of DME! So to make this a bit more manageable I was thinking of splitting the batch into two separate mashes and combining the wort in the kettle.

Has anyone tried anything this big? I know efficiency is going to take a big hit, will I get anywhere close to the OG? Will US-05 even ferment up to 14%, and if not any suggestions??

I used a single packet of MJ's yeast rehydrated for my king kong (12.86%) which was suitable for 14% - the OG for that was 1.108 - FG -1.010, as your batch size is 18 litres and mine was 20.5 that should be doable. Kviek can handle big numbers but I wouldn't risk US-05.

 

[foxbat]

My concern would be the sugar being an easy to consume treat for the yeast at the start of fermentation.

I had that concern when I did my Belgian with 15% sugar so I used a monosaccharide: dextrose (a.k.a. 'Brewing Sugar') instead of a disaccharide: cane sugar. White cane sugar is certainly cheaper but will need to be boiled and the fermenter opened up to add it whereas dextrose can go straight into the boil for sterilisation.

 

[foxbat]

As you can see this 18L batch has over 10Kg of grain plus 1kg of sugar and 500g of DME! So to make this a bit more manageable I was thinking of splitting the batch into two separate mashes and combining the wort in the kettle.

Has anyone tried anything this big? I know efficiency is going to take a big hit, will I get anywhere close to the OG? Will US-05 even ferment up to 14%, and if not any suggestions??

Try entering your numbers into this mash/lauter simulator spreadsheet. Don't include the sugars. It'll tell you whether your target gravity is achievable or not. And if not, then you can increase the size/number of sparges you do and increase the boil length to hit your target. The metric units didn't seem to work for me but US gallons/lb worked fine. Doug is very responsive to questions about the calculations over on HBT if you start a thread.

 

[Sadfield]

I had that concern when I did my Belgian with 15% sugar so I used a monosaccharide: dextrose (a.k.a. 'Brewing Sugar') instead of a disaccharide: cane sugar. White cane sugar is certainly cheaper but will need to be boiled and the fermenter opened up to add it whereas dextrose can go straight into the boil for sterilisation.

I think Belgian brews are more forgiving as the malt portion of the recipe is usually quite simple and mashed for fermentability. There's alot of dextrins malts in that RIS recipe and DME, which has a reputation for being less fermentable than equivalent malt wort. I'd still consider adding brewing sugar later into the Fv.

 

[strange-steve]

Thanks for all the comments on this, I appreciate the collective wisdom of the forum :hat:

So swapping the flaked oats for malted oats is good idea, done.
Adding the sugar a few days into fermentation, another good idea and something I've done successfully in the past.
Add coffee at flameout, done.
Kviek yeast is another good shout, I actually have some Voss that Beercat gave me a while back that I haven't used yet, I'm guessing this would mean underpitching isn't such a risk either?
@foxbat I had a look at that SS but didn't really know what I was looking at I'll have a better look when I get time later.

I've been back and forward on whether to do two split mashes or to do a reiterated mash. From what I can find though, reiterated mashing seems to be the more efficient option so I might go that route.

 

[foxbat]

I had a look at that SS but didn't really know what I was looking at I'll have a better look when I get time later.

You need to hit a post-boil of 1.112 from the grains in the mash. I entered what I think are the correct figures for your recipe (not incl. sugars and before any suggested edits above). Here's the result:

The good news is that if you follow the mash/sparge schedule in the lower table and you hit 90% conversion efficiency in your mash then you should end up with 1.112 with a 2 hour boil. I would also mash for two hours and sparge really thoroughly, maybe at the expense of a thicker mash. I don't have a grainfather so I'm not certain whether the grain bill + mash water would present a capacity issue for you.

 

[jceg316]

I've not brewed anything that strong, but looks nice. As for yeast, S-33 should do the job if US-05 doesn't. Despite what Fermentis say about its character, S-33 is really clean. I've used it on on high gravity beers before (>= 1.070) and it ferments fast.

 

[-Bezza-]

I look forward to getting this beer in this year's secret santa beer swap.

 

[Sadfield]

Is it your GF you are brewing this on? If so, I'm look forward to hearing how you get on, as I've not known anyone go this big on one.

 

[strange-steve]

You need to hit a post-boil of 1.112 from the grains in the mash. I entered what I think are the correct figures for your recipe (not incl. sugars and before any suggested edits above). Here's the result:

The good news is that if you follow the mash/sparge schedule in the lower table and you hit 90% conversion efficiency in your mash then you should end up with 1.112 with a 2 hour boil. I would also mash for two hours and sparge really thoroughly, maybe at the expense of a thicker mash. I don't have a grainfather so I'm not certain whether the grain bill + mash water would present a capacity issue for you.

Thanks for that :hat:
I think it is possible, from my calculations I need a pre-boil SG of 1.078 which actually isn't that unreasonable, especially if using a reiterated mash.

I look forward to getting this beer in this year's secret santa beer swap.

It might be ready for Christmas next year

Is it your GF you are brewing this on? If so, I'm look forward to hearing how you get on, as I've not known anyone go this big on one.

Yep on the GF. I've been as high as 11.5% with an eisbock using 9kg of grain but that was with an OG almost 50 points lower than this!

@David Heath as our resident GF expert, do you reckon this is doable? I've watched your video on reiterated mashing and it definitely seems the way to go, so thanks for that :hat:

 

[Sadfield]

@strange-steve Sorry, wasn't trying to cast doubts. Just fascinating to see how different setups work when pushing the envelope.

 

[strange-steve]

@strange-steve Sorry, wasn't trying to cast doubts. Just fascinating to see how different setups work when pushing the envelope.

Don't worry, the doubts were already there

 

[lancon]

when doing strong ale make sure wort very well oxygenated at pitching is the advice I was given by a retired pro brewer, otherwise yeast bite? It starts off tasting nice but by the end of the glass not pleasant. I am planning on doing an Imperial Porter 10-12% but will brew a normal porter and then use the yeast from that for the Imperial, just pitch onto it. I was advised few litres in, stop and shake the FV for about 10 minutes to oxygenate.