Imperial stout recipe revision

[Erik the Anglophile]

Hello all, I posted a recipe for an Imperial Stout some time ago, and well this tuesday is Brewday. I have been looking around a bit more and simplified the grain bill a bit among other changes.
For the first one I posted, I had mainly looked at american, sweet and 10%+ iterations of the style, wich is not what I personally look for. I am after a more classically English variant, and do absolutely not mind a little "harsh" or gunpowdery roastyness, I even want it to a certain degree.
Anyways here goes the recipe I deviced.

Batch is about 11L post boil without accounting for losses to trub while tranferring to fermenter.

Grainbill:
Maris Otter 3210g (75%)
Crystal 150(EBC) 260g (6%)
Roasted Barley 260g (6%)
Oats 210g (5%)
Brown Malt 170g (4%)
UK Chocolate malt 170g (4%)
Mash at 65c for 90 min

Boil for 120 min
21.8g Challenger 60 min
18.5g Fuggle 60 min
13g Fuggle 15 min
10g Bramling Cross 15 min

Est OG 1.086
FG 1.020 ish
ABV 'bout 8-8.5% I reckon
IBU 70

How's it look?

 

[Golddiggie]

Why two hop varieties at 60 minutes?? Since you won't get anything other than bittering from them, seems like a waste of Fuggle hops to me.

I wouldn't do as complex a grain bill, but that's just me. I think they crystal 150 will get lost with the other, darker, malts added.

 

[DBhomebrew]

Out of curiosity, what's your inspiration for this one? Is it based on any particular sources?

I've been meaning to brew up a classic British-style Imperial and have settled on this one off Shut Up. Very simple grist. Picking up ingredients today, should get it done early June.

http://barclayperkins.blogspot.com/2012/02/lets-brew-wednesday-1914-courage.html?m=1
Agreed about the early Fuggles. They've been about 3%AA for me recently. Great for a big late charge, but not so much for bittering. It'd be a ton of vegetation. I'll likely swap something else for the 60m in the recipe I linked.

BU:GU may be a bit high. Some will age out for sure, but at 8-8.5% I figure you're not talking years.

Which yeast will you use?

 

[Erik the Anglophile]

That's true, might swap the bittering charge to all challenger. I was running out of challenger when writing this recipe but I got some new bags now.
You reckon I should dial down the IBU a bit? Something like 60-65? I pondered about just going with brown malt and and roasted barley but decided to add some chocolate malt aswell, compared to many modern imp stouts it's still a fairly simple grain bill.

 

[Dr_Jeff]

Consider dropping the brown malt.

 

[Golddiggie]

All depends on the actual flavors you want in your glass (for the malt bill).

I tend to aim at the middle of the IBU range for a style. That way if things get a little away from me (doesn't happen typically, but better to be safe) I don't have issues. With imperial stouts listing 45-65 IBU, I'd aim for mid 50's.

 

[Erik the Anglophile]

I did some remodeling of the recipe, and it this is what I got:
MO 77%
Roasted Barley 8%
Crystal 150 6%
Oats 5%
UK Chocolate 4%

Ditched the Fuggle and went with only Challenger as bittering, the 15 min additions stay the same, and dropped IBU to 60.

@DBhomebrew I am gonna use a yeast called Brewly English ale, a Swedish domestically produced yeast from a yeast manufacturer that produces yeast on contract for commercial breweries around Europe, and now they have a strain available for homebrewers they produce for a HBS over here.
Have only tried it in a brown ale that is not done conditioning, but from tasting at samples and while bottling, it is sorta like S04, but more of the good estery sides of it and none of the funky tart sourdoughy tang.

 

[DBhomebrew]

I am gonna use a yeast called Brewly English ale

Right, I read that thread.

I tend to aim at the middle of the IBU range for a style. That way if things get a little away from me (doesn't happen typically, but better to be safe) I don't have issues. With imperial stouts listing 45-65 IBU, I'd aim for mid 50's.

I'll add on to this about keeping the BU:GU in mind. If your OG is at the very low end of the style, your bittering might want to be as well. But style guidelines are just that. If you like high bitterness, go for it!

 

[Erik the Anglophile]

I don't think 60 IBU for an OG of.086 is gonna give it any extreme bitterness, but if I find it a tad bit too bitter I'll just adjust it down a little next time. After all this is my first attempt at an Imperial Stout and I will probably have to rebrew it a few times with minor changes to perfect it to my liking
My thought is to ferment at 18c, as the higher gravity will probably encourage some ester production in itself, and while I use an english yeast and want some esters going in the background, I don't want too much of it.
Oh and water will be adjusted to Cl 100mg/L SO4 102mg/L Na 40mg/L Ca 72mg/L

 

[tracer bullet]

Off the top I'm thinking 60 - 70 IBU for that recipe a little bit above, but as with all things, this depends on your tastes. It's about where I think I'd like it at that ABV. Agreed fully to coordinate the range, since you're on the lower end of ABV you might stick around the lower end of the IBU as well.

I did 15% dark malts in my last RIS and I don't think it was too much, I'll do that again for sure. I did oats as well and kind of think it was a waste of time, but that said I'm sure I'll do it again too so I don't change too many variables on the next one.

I also did 5% Crystal 120 on my last one, and it was either it or the Irish Ale yeast (which I don't think I underpitched, but might have) that dragged the whole thing towards a sweet direction. Final gravity was fine so I don't think it was that. But again you get into personal opinion.

Recipe looks good but there are SO many variations that all turn out fine, you really just can't say if something is better or best. But what you've got listed certainly will be good, nothing stands out as being wrong or bad.

The brown malt might well have gotten lost but pale chocolate, roasted barley, chocolate and black are all good options. Pick 2 or 3, decide on a total percentage among them (10, 12, 15, etc. %), and then divvy them up within that based on what you think sounds good. Then go for it. And when drinking it take notes for next time (too much of this, not enough of that, or if it simply turned out perfect).

 

[Erik the Anglophile]

Yeah there are many variables that when changed just even a little bit, will produce a very different end result.
I am also thinking about in the future making a variant inspired by the Fullers imperial with Invert#3 and Crystal ~8% each and around 10-12% Brown and 3% or so chocolate, this will be more of an imperial porter though.
Oh, and do you think I will need to add a few grams of conditioning yeast at bottling? This is no super high gravity nor abv brew and should probably be done and bottled in 3 weeks, and the yeast has an alcohol tolerance of 10% so it should be able to referment and carb up in the bottles. But it felt best to ask anyways, and I'll let them sit 2 months in room temp before opening the first one to check carbonation anyways to be sure.

 

[InspectorJon]

I've bottled a few imperial stouts. One after 5 months aging. I have had no issues with them carbing up on their own. No need to add conditioning yeast with your current plan.

 

[Erik the Anglophile]

Brewed it today, hit my preboil volume spot on, although my efficiency had suffered a little more than I thought and pre boil SG was 3 points low. However my OG ended up at 1.077 instead of 1.083 as I thought it would with the slightly lower pre boil gravity.
I have been tinkering a bit with my parameters in Beersmith, and think my final culprit to eliminate is cooling loss/shrinkage as I appear to have none opposed to the pre set 4%, I often end up with pretty much the same volume given as postboil before cooling in to the fermentor, and I have double checked my actual boil off so that's correct, and have struggled with gravities often coming out a bit low.
The wort tasted heavenly before pitching the yeast, not as roasty as I would have thought but I may have been decieved by the sweetness, hopefully it will come out allright as I lowered the IBU a bit before the first hop addition, and with the cooling losses that dont appear to happen but BS calculates on, my IBU should be around 50.

 

[DBhomebrew]

cooling loss/shrinkage as I appear to have none opposed to the pre set 4%

I'm not at all familiar with Beersmith, but 4% is pretty much the cooling shrinkage, no evaporation loss. I lid my kettle at flameout and don't open it again until time to pitch. The difference between hot post-boil and pitch temp post-boil is just about 4%.

 

[tracer bullet]

Maybe you know it, but the bigger the beer the lower the efficiency. Generally speaking anyhow. It's basically a water to malt ratio, there's only so much that can be extracted before the water has as much in it as the grain does. Eh I didn't explain that correctly but big beers get lower efficiencies.

What I've taken to doing is upping the water volume and then boiling it off. Either a harder boil or a longer one, depending if I'm using propane or my electric Anvil, how full things are, and so on. But let's say I add an extra gallon between the mash or sparge, I get more extracted, and then I boil it back off. Once it's boiled off, and I'm at my expected "start of boil volume", I then start my normal boil power, 60 minute timer, hop additions, and so on. And I'm at a much higher gravity than if I hadn't done all of that.

There's one other option for next time too, have a bag of DME dry malt extract on hand! Especially for an Imperial stout, it is unlikely that you would taste the additional ingredient.

 

[DBhomebrew]

I find @doug293cz's efficiency prediction spreadsheet to be highly accurate. Like, scarily so.

Of course, any prediction relies on quality inputs. I know you mentioned double checking your boil-off. How do you measure your volumes? I stick a stainless metric ruler into the kettle and plug the finding into the formula for the volume of a cylinder. Given the diameter of my kettle and that I read the ruler to the nearest mm, my volumes are to the nearest 1.2something ounce.

Yeah, I mix metric/Imperial to my heart's content.

 

[Erik the Anglophile]

I measure with a ruler aswell, I measure the amount of wort before boil after mash + sparge and have made markings on my fermentation bucket. The thing is, I usually end up with a little too much and too weak wort after boil, even if pre boil gravities and volumes are correct.
Then I went in Beersmith and set the cooling shrinkage to zero, and the new decreased post boil volume was decreased pretty much exactly half a liter, wich is about the same amount I usually end with too much of in the fermenter. I guess if you never measure you volumes really hot, the cooling shrinkage is negligable?

 

[DBhomebrew]

Mash temp (~150F) to pitch temp (~65) is roughly 2.7%

If you mash out and you're measuring your post-lauter/pre-boil at ~170, it'd be a touch more.

 

[Erik the Anglophile]

I usually drain the first runnings quickly and add sparge water hot enough to reach 75-80c and let it sit a little while to do a combined sparge and mash out, I suppose it loses some heat while filling the boil kettle though. I'll try to decrease shrinkage to 2% and see if that gets me closer.

 

[Oleson M.D.]

I do not agree with “the bigger the beer, the lower the efficiency”. We hit 1.1XX in our last Barleywine. The secret is do not over sparge. Stop your runoff when you hit your planned OG.

 

[DBhomebrew]

I do not agree with “the bigger the beer, the lower the efficiency”. We hit 1.1XX in our last Barleywine. The secret is do not over sparge. Stop your runoff when you hit your planned OG.

How did your barleywine pre-boil volume compare to your typical batch?

 

[Oleson M.D.]

How did your barleywine pre-boil volume compare to your typical batch?

It was a 5 gallon size batch. I stopped the runoff when the volume was correct for a 2 hour boil. The OG = 1.116, BRIX = 27.1.
Hard to compare, as most often a 10 gallon batch is brewed, lower gravity styles like Pils, Vienna Lager, etc.

 

[tracer bullet]

You're kind of comparing apples to oranges. I didn't say you couldn't get high gravity, of course you can, via a variety of means. But stopping run off early and having high efficiency aren't the same thing. I'm saying that the more grain you add, to a given amount of water, the lower the extraction from the grain becomes. It's fairly straightforward and I think fairly well established.

 

[Oleson M.D.]

Well...the runoff was stopped at the time we hit the correct volume, not stopped early. The HLT water was cut, so as to not dilute the mash.
The FG = 1.033 / BRIX = 15.4
10.44% ABV

 

[DBhomebrew]

It was a 5 gallon size batch. I stopped the runoff when the volume was correct for a 2 hour boil. The OG = 1.116, BRIX = 27.1.
Hard to compare, as most often a 10 gallon batch is brewed, lower gravity styles like Pils, Vienna Lager, etc.

The comparison is exactly the point of the statement "bigger the beer, lower the efficiency". Tough to refute the statement by not comparing two batches with all else being equal other than gravity.

I have Doug's spreadsheet open as I brew a batch. By increasing grain amount (thereby gravity) from 9.5 to 10.5lbs, gravity went up, total water used went up. Preboil and postboil volumes remained the same. Efficiency went down. Final output was my usual volume at a higher gravity.

It's the whole grain absorption ratio at work. More grain, more wort gets absorbed.

Sure, you can adjust for it.

 

[tracer bullet]

It's the whole grain absorption ratio at work. More grain, more wort gets absorbed.

Even accounting for this, if the amount that is able to be run off and / or the sparge volumes otherwise remain the same, the less sugars they can carry out the first time and then rinse off later - the less efficient the water is at extracting that sugar.

 

[Oleson M.D.]

The odd thing is we hit our gravity calculations spot on. Did not do anything different with this beer. And the calculator is based on a brewhouse efficiency of 75%.
This was the first time we ever hit 1.116 OG.

Only a 5 gallon size, but way more concentrated sugar.

 

[Erik the Anglophile]

Did you boil it obscenely long? If there was a very long boil requirung a very large pre boil volume giving a decent amount of sparge water that could explain the retained lauter efficiency. I mashed pretty thick for this one but still ended up with a rather thick sparge, wich I accounted for, but I probably should calculate for a few percent more in efficiency loss the next time I brew this.

 

[Oleson M.D.]

The Barleywine was a two hour boil. Ended with 5.5 gallons, started with 7.5 gallons.

 

[DBhomebrew]

Did not do anything different with this beer.

The Barleywine was a two hour boil.

Only a 5 gallon size

Are your usual batches 2hr boils and 5gal as well?

 

[Oleson M.D.]

Yes, whenever we brew a high gravity beer.

 

[DBhomebrew]

Sorry, by 'usual' I mean normal gravity. We're comparing big gravity efficiency to low gravity efficiency.

 

[Erik the Anglophile]

well I did a 1.5 hour test boil of 15L, to simulate an average wort boil, and measured the volumes a bit more precisely. Turns out my boil off was set a little bit too high.
Then I did a little scienceing and got a factor of 0.977 to divide my desired at room temp wort volume with to get the adjusted for post mash temp volume I need to collect, so lets say 16.3 L becomes 16.7L when adjusted for the higher temp.
This should get my volumes in better order

 

[DBhomebrew]

I find boil-off to be the most difficult factor to dial in for constancy.

 

[Oleson M.D.]

Yes, we figure 1 gallon to 1 1/2 gallons per hour of boil.
Depending on how vigorous the boil is.

 

[tracer bullet]

Turns out my boil off was set a little bit too high.

Haha I wondered what you were talking about then remembered it was your thread. Sorry if we helped stray off.

Boil off rate is easier w/ electric but even then varies, and as I reminded myself just yesterday also fairly hard w/ propane. I have over the years developed a pretty good idea of what it should look like but even then it can change on the fly - might be my regulator going out. I tend to also make visual checks of the boil-off and if I see markedly higher or lower than about a 1/4 gallon every 15 minutes I can react to it. Factor in water expanding when hot (4% they say), the kettle markings being off, and.... yeah. This is one of those "close is close enough" things for me.

 

[Erik the Anglophile]

Haha I wondered what you were talking about then remembered it was your thread. Sorry if we helped stray off.

Boil off rate is easier w/ electric but even then varies, and as I reminded myself just yesterday also fairly hard w/ propane. I have over the years developed a pretty good idea of what it should look like but even then it can change on the fly - might be my regulator going out. I tend to also make visual checks of the boil-off and if I see markedly higher or lower than about a 1/4 gallon every 15 minutes I can react to it. Factor in water expanding when hot (4% they say), the kettle markings being off, and.... yeah. This is one of those "close is close enough" things for me.

I boil on an electric portable induction heater in the kitchen, but I have the same approach, close enough is good enough. It's just that it has been a bit too off to be comfortable with but I think I might have adjusted it to an acceptable level of accuracy now.
I'll have to try it out in the best bitter I'm gonna brew next, but it will likely be awhile until next brew as our second kid is coming around june and they say attending childbirth is more important than brewing beer. So far I have not really heard any convincing arguments for that proposition but I guess I will have to fold.