Reducing Brew Length to increase ABV% ?

[DC]

Hi all, I am looking to brew a Stout for my next all grain brew and was looking at making a 5 gallon batch at 5%. But after recently sampling a bottle of Durham Breweries Temptation Russian Imperial Stout 10% I am toying with the idea of trying a Russian Imperial Stout of around 10%. If I wanted to brew a stronger Stout would reducing the brew length increase the ABV% of the Stout and if so by how much would I need to reduce it to achieve 10% ? I have just about enough Pale Malt left to do 2 brews one being the original Stout I planned at 5% and then use the last of the pale malt for an experimental brew. Should I just up the quantity of the pale malt to try and up the ABV% of the stout to Russian Imperial strength or just reduce brew length? Or a bit of both?

Cheers DC

[Spud395]

You will find you're efficiency decreasing as you try for a stronger wort.

If you normally hit 75% mash efficiency allow more like 60-65% for a really big beer.

[boingy]

But basically yes. You use more grain in the mash and/or less water in the sparge. You can also boil for a bit longer to concentrate the wort a bit but this can be a bit tedious.

As for the quantities, you can either base it on an existing recipe or use some of that there new-fangled brewing software.
Also, choose your yeast carefully. 10% is a big ask for some beer yeasts.

[Brotherton Lad]

This is in the recipe section:

Real Ale Almanac IMPERIAL RUSSIAN STOUT
by norman » Sun Sep 24, 2006 4:57 pm

IMPERIAL RUSSIAN STOUT John Smiths Tadcaster.

25l batch OG 1102 ABV 10% 235 units of colour 50 units of bitterness.

PALE MALT 5955 gms
AMBER MALT 2134 gms
BLACK MALT 284 gms
SUGAR 1594 gms Added to boiler.

HOPS boil time 90 minutes

TARGET 89 gms

I suggest one of the high gravity yeasts WHITE LABS Super HIgh Gravity WLP099.
This is one of the strongest beers brewed in Britain and needs BOTTLE CONDITIONING,and a long maturation time.
norman
Piss Artist

Posts: 273
Joined: Sun Jul 09, 2006 12:00 pm
Location: cleveland ne England

[darkonnis]

I've seen quite a lot of pro brewers opting for the boil down option, I seem to recall Critch mentioning he did a 3 or 4 hour boil for one of his and I know brewdog do. There might be more to it than just getting down to gravity/saving a few quid on grain. I've yet to get this far myself as I'm still playing with a million and one other little things (like my botched water treatment ) so if you try it do let us know how you get on!

Boingy, I thought most beer yeast where ok till coming close to 10% without a starter? Not saying you're wrong, just making sure I've read/assumed correct before I try it myself and bugger it

[Scooby]

If you boil 25l of 1.050 wort until you have 12.5l the gravity will be 1.100. That may take 4 or so hrs, not only will you be evaporating water you'll
be driving off other desirable components.

The answer to your questions are; halve the brew length = double the og. Double the grist = double the og. Do you want 5 gallons at 10%?

BTW never noticed a drop in efficiency as I increase wort strength and can't see why efficiency should drop.

[boingy]

I think the efficiency drops because it's hard to sparge all the sugars out with minimum water. The obvious solution is to do the big beer with no-sparge and then sparge to make a second, weaker brew.

As for the boil-down option, I'm sure I've recounted on here my tale of making a Dave Line barely wine as a teenager in my mum's kitchen, boiling off a gallon and a half of water with no steam extraction and no thought about where the water was going to end up...

[orlando]

I don't know about other brewing software but in BeerSmith 2 you can either adjust the brew length or specifically change the gravity, the software will then automatically change the relative strength of the beer by adjusting the recipe accordingly and will do so without changing the flavour profile you are looking for as it adjusts all the parameters you originally set.

[Scooby]

I think the efficiency drops because it's hard to sparge all the sugars out with minimum water. The obvious solution is to do the big beer with no-sparge and then sparge to make a second, weaker brew.

As for the boil-down option, I'm sure I've recounted on here my tale of making a Dave Line barely wine as a teenager in my mum's kitchen, boiling off a gallon and a half of water with no steam extraction and no thought about where the water was going to end up...

Re efficiency, could be, the strongest I've done is an 8%, still got my usual 80%+ efficiency batch sparging.

I once rapidly boiled 4l down to a few 100ml thick syrup on a stove with extractor hood. Knacked the motor when it got gummed up. That's when I realised it was more than water vapour being driven off.