Monster Imperial Stout

Hello all,

I brewed an imperial stout yesterday. Last time I did one I had horrendous efficiency and ended up around 8.5%. I wanted to make sure that I got higher this time so decided to do a reiterated mash. I split the grain bill in half and did two mashes, First mash had a sparge, second was no-sparge using the wort collected from the first. Ingredients were:

9.4 kg Maris Otter
0.8 kg Brown Malt
0.6 kg Amber (Crisp)
0.4 kg Black Malt
0.4 kg Crystal
0.4 kg Roasted Barley
1 kg Invert #3
0.5 kg table sugar

104 g Green Bullet (11.2%) - 60 mins
39 g Northern Brewer (7%) - 60 mins
28 g Magnum (9.2%) - 60 mins

Both mashes were for an hour at 65C. Once cooled, I aerated the wort for at least 30 mins with a pump and then pitched 2 packs of Windsor and 2 packs of US-05.

All went pretty well. In fact too well! I ended up with 21L of 1.129 wort! Quite a bit higher than I'd expected.

Its bubbling away happily now, but I'm worried about whether it'll finish out ok. I'm hoping I can get it down into the high 1.020s. If so it'll be around 13.5%! I'm wondering if the yeast will cope with that or if I need to get my hands on a high gravity yeast that I can add to finish it off.

Any of you had experience of brewing a beer like this?

Wow that's a lot of grain and a lot of yeast but I'm guessing you'll need it.

Where did you get the recipe or did you design it yourself?

Closest I ever got was this one but the OG was much lower at 1.085:
http://www.thepourreport.com/imperial-v ... ut-recipe/

It was absolutely lush though. Yours sounds like one that could do nicely for years to come.

Edit: mine finished at 1.020 but it had lactose in it so not sure on the ABV

Wow that's a lot of grain and a lot of yeast but I'm guessing you'll need it.

Yeah way more than I would normally use. Had to do the double mash thing so I could split the grain otherwise it would never fit in my tun.

Where did you get the recipe or did you design it yourself?

Its my own. Mainly using the ingredients I had to hand. Hoping it'll come together nicely. Tasted pretty good before going into the FV.

Yours sounds like one that could do nicely for years to come.

I'm guessing it'll be best after a good bit of ageing. Hopefully I can keep my hands off it.

With that high of an OG you’ll likely find that your yeast will not get down below 1.020 as the brew ferments and the alcohol content increases.

You could add a finishing yeast, or just leave it with loads of body. I’d probably split the batch and ferment half with a finishing yeast to get the FG lower, then blend the two beers.

Nottingham or US-05 would be my choice outside of anything too weird and wonderful. I’d add maybe 100g of sugar to help get things underway again, and also help with attenuation.

My last imperial stout only got down to 1.024 with US-05 and a much lower OG. It tasted great and not at all too sweet, so if I can get this one down below 1.030 I'll be happy.

My worry though is that the US-05 I pitched might start to struggle as the abv creeps up to around 11 or 12%.

I've got some more US-05 or some Nottingham in the fridge but I'm not sure Nottingham will do any better than US-05 and I don't see the point of pitching more US-05.

Was thinking maybe a belgian yeast might finish it off well? Something like Mangrove Jacks Belgian Tripel? Whitelabs do a Super High Gravity yeast, but I'd like to avoid making a start of possible.

Was thinking maybe a belgian yeast might finish it off well? Something like Mangrove Jacks Belgian Tripel? Whitelabs do a Super High Gravity yeast, but I'd like to avoid making a start of possible.

I've just used 2 packs of Mangrove Jacks Belgian Tripel on a westy clone and it got stuck at around 1.040 (OG 1.092). There's a thread on here but I don't know how to link it.

I've ended up pitching another packet of the same stuff but started off on spraymalt to see if I can get it hooked on the malt instead of the simple sugars. You might be okay using it though as I would imagine if yours gets stuck, the invert will be long gone by that point.

On the plus side, it gives off some lovely dark fruit flavours which might work well in a big stout.

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Sounds monstrous! In a good way!!

Checked the gravity today after 6 days. Down from 1.129 to 1.054. So around 10% abv so far.

Its still going strong. Airlock bubbles every 15 secs or so. Hopefully it'll carry on long enough to get to where it needs to be.

Tasted it and it was really thick, almost a milkshake like mouthfeel! Loads of cocoa & coffee flavours. Really pleased with it.

That's my favourite type of beer. Something you can sip on a cold winter night and get slowly pickled. That or a Samichlaus...

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Ok I've roused the yeast a couple of times now and its been at 21C for almost a week but it's staying stubbornly around 1.054. Still bubbling from time to time but I can't see it coming down much more.

It tastes great but way too sweet, so I'm thinking of how to get it down.

Option 1 - pitch a couple of packs of US-05. Might work, but I'm thinking that the wort is a pretty unfriendly place for yeast just now (high abv, low oxygen) and that US-05 will just sink to the bottom and do very little.
Option 2 - pitch WLP099 (Super High Gravity Ale). Its more alcohol tolerant than US-05 and I can make a decent sized starter before pitching. I've seen this option talked about a lot in forums.

Any thoughts or advice?

The flavours you want are probably there. Thought about Gervin GV7?

Thought about Gervin GV7?

Cheers - Not seen that one before - looks like a wine yeast. Think it would be similar in idea to pitching champagne yeast? I read that champagne yeast can only ferment simple sugars and I think that my stout will mainly have complex sugars left, so may not work.

From what I've read, WLP099 should cope with the high abv and the complex sugars so I think I'll go with that. Will make a starter over the weekend.

Ok I've roused the yeast a couple of times now and its been at 21C for almost a week but it's staying stubbornly around 1.054. Still bubbling from time to time but I can't see it coming down much more.

It tastes great but way too sweet, so I'm thinking of how to get it down.

Option 1 - pitch a couple of packs of US-05. Might work, but I'm thinking that the wort is a pretty unfriendly place for yeast just now (high abv, low oxygen) and that US-05 will just sink to the bottom and do very little.
Option 2 - pitch WLP099 (Super High Gravity Ale). Its more alcohol tolerant than US-05 and I can make a decent sized starter before pitching. I've seen this option talked about a lot in forums.

Any thoughts or advice?

With an OG of 1.129 and a FG of 1.054 you have a 9.8% beer, so your yeast has likely given up due to the high level of alcohol.

However, you only have around 55% attenuation, so that’s most likely going to be too sweet.

If you got it down to 1.025 you’d have a fairly average attenuation of around 80%.

I’d make up a 1L starter with a strain with high alcohol tolerance as you’re going to end up with a 13.5% beer if you finish at 1.025

I don’t know of any beer strains that will cope with that. Champagne yeast is probably the only route.

WLP099 is apparently good up to 25% - although it needs a lot of babying to get that high. Will give it a go and see what happens....

I'm in a similar situation due to my own fault of subbing in CML yeast for US05 and not checking the alcohol tolerance. I went and bought a vial of Brett (645 so quite a mild and very traditional British version), that and a fair bit of time will hopefully get me to where I want).

I'm in a similar situation due to my own fault of subbing in CML yeast for US05 and not checking the alcohol tolerance. I went and bought a vial of Brett (645 so quite a mild and very traditional British version), that and a fair bit of time will hopefully get me to where I want).

How much did that set you back? I've been looking myself and couldn't find much Brett online and the small amount I could find was a tenner plus postage.

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£7 quid from the Malt Miller. I love that Rob always shows the date on his website too, in this case is was pretty short dated but typical of their great service they actually swapped it out for a much fresher vial without me asking.

EDIT: I will streak some anyway so will get to use multiple times.

Nice. I was debating dosing my stuck quad a couple of weeks ago but I've already ploughed too much cash into it trying to get it moving. I definitely want to use it at some point though and £7 ain't too shabby.

Not sure it would work in a monster stout though.

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I will let you know in 8 months
I think it should do and even though they say up to 12% ABV tolerance they are often conservative, I am hoping that it goes to about 13.5-14% ABV before stopping completely and leaves a decent mouth feel.

Well, I did a 3L starter of WLP099 and pitched after decanting. I did get some activity, but not much Left it for a couple weeks and took a reading today. 1.048. So its now around 11%.

Not sure what else I can do tbh. Had a taste and it's tasty, but it's also very sweet.

Well, I did a 3L starter of WLP099 and pitched after decanting. I did get some activity, but not much Left it for a couple weeks and took a reading today. 1.048. So its now around 11%.

Not sure what else I can do tbh. Had a taste and it's tasty, but it's also very sweet.

Maybe brew a small batch of stout with lots of sugar or maize to thin the body, and also mash low 63C. That might be enough to blend and make a good beer. You’d want to have your thinner beer more bitter as well to counteract the sweetness.

Alternatively, just dump it and put it down to experience.

Well, 5 months have gone past for this one, so an update....

Turns out I'm an eejit and the yeast that I pitched and thought was WLP099 was actually a Kolsch yeast that I had planned for the following weekend. I mixed them up Realised when I went to make a starter for the Kolsch.

So instead of making a Kolsch starter I made a big starter with the WLP099 and pitched it. Got a bit of activity in the first couple of weeks but nothing after that.

Just left it alone after that and checked the gravity after about a month and half. Down to 1.037. Still pretty high, so left it another month and a bit. It came down some more, and so on...
Took a reading a couple of days ago and its down to 1.026. Its around 14% now.
Tastes good. Strong, but good!

So now my question is...now its down around the gravity that's reasonable for an imperial stout, should I bottle?

My worry is that the WKLP099 is not finished and it'll continue to ferment in the bottles and at the very least I'll get over-carbed beer or if I'm unlucky, bottle bombs.

I could leave it in the fermenter for longer (why not, its already been in there for 6 months ), but I'm worried it'll dry out too much.

What do you think?

Take another reading in a couple of weeks. If it's not moved bottle it..... but maybe be a bit frugal with the priming sugar!
Sounds good. The last 14%beer I had went down the drain after 2 mouthfuls!

At 14% it will probably not be drinkable for another year in any case. 1.026 is a reasonable FG for a beer that big imo.