Help me understand this "barley wine" recipe

[snookums]

I've decided to start an annual tradition of brewing a high-gravity beer each year at Easter. For the first batch I picked out what I though was a simple recipe from the Classic Beer Styles: Barley Wine book. I'm all set to brew tomorrow, but looking at the recipe in detail I see some things that don't add up. Translating from American units, for a 5 US gal./19 L batch, the recipe goes like this:

Buffalo Bill's Barley Wine - Brown Sugar (How Come You Taste So Good?)

7.5 kg Pale Malt
725g Dark Crystal
2.5 kg Brown Sugar

255 g Cascade, 90 min, 69 IBU
225 g Cascade at flame out

Infusion mash at 70C for 90 minutes, sparge for 5 minutes

O.G. 1.100, F.G. 1.025, 9.3 % ABV

After calculating this out, it seems that to get only 1.100 with that malt and sugar bill would mean a mash efficiency no more than 40%. I batch sparge, and really have no idea about fly sparging. Is such a low efficiency expected with only 5 minutes sparge and that amount of grain? I guess to replicate this I'll go "no sparge", just adding a little extra water to the lauter tun and collecting only first runnings. Does that sound reasonable?

Second problem is that hop schedule. Even at the lower end of their usual AA range at 4.5%, I don't see how you'd get only 69 IBU from that amount of Cascade. It seems like a good 50% more than what you'd need. Is there strong non-linearity of bittering at higher IBU that I'm not accounting for? IBU of 69 isn't even that extreme.

 

[manticle]

The larger the malt bill (usually) the lower the extraction. The higher the gravity, the lower the hop utilisation.

Might explain some of it, don't know about 40%.

 

[Mardoo]

IIRC the general limit of wort gravity you can get from a sparge is 1.080, which is just a different way of looking at what Manticle said. That's from the Brewstrong High Gravity series, which is absolutely worth listening to a few times. That could be the difference you're seeing.

 

[MartinOC]

If you read the book in detail (I'm going back through it atm..it's my current "bedside" book), you'll understand that to make a beer of this magnitude, you're going to have to expect poor extraction efficiency & poor hop-utilisation efficiency. It's the price you pay for making such big beers.

'Pretty sure the 5-minute sparge is intended only to get the highest-gravity wort intended for the barley wine itself & the 2nd runnings are intended for a "small" beer.

You can always try the Scotch-ale system & dump/boil the 2nd-runnings onto the "leftovers" from the barley wine after you've run it off to the fermenter to get another beer (assume about 10-15% utilisation from the "spent" hops).

Just have a go at it with your system & see what you get.

 

[snookums]

Yeah, I'm thinking I'll just roll with it and see what comes out of the lauter tun. Maybe adjust the sugar addition, or the final volume depending on what I get.

I actually plan on scaling this down to a 13 L batch, which brings things down to 5.5 kg of grain (the capacity of my preferred mash tun). Last weekend I mashed almost exactly that much for a 22 L batch of American Pale (essentially a big yeast starter for the high-gravity brew). I collected about 16.5 L from that mash in 2 batches (small boil kettle -- 13 L is my normal batch size), and back-calculating now, the efficiency there was 55%. So 40% with a single running doesn't sound too far off.

Martin, I think you're right -- this is a scaled down commercial recipe, and I'm thinking now they most likely make another beer with the later runnings.

I need to remember to RDWHAH The whole high-gravity thing is all about experimenting anyway. Last time I tried it was a 1.100 Imperial Stout in 2004. It wasn't great, and I got discouraged, but I knocked the cap off one of the last few bottles I'd been saving a few months back and it was so good :icon_drool2:. I'm determined to just go for it, and drink my mistakes.