One BIAB brew, two different worts

Post #1 made 4 years ago
I've been exploring around the idea of Parti Gyle brewing and currently mashing a Fullers style English ESB.

The idea of Parti Gyle is to get two worts out of one grain bill, a strong one (first runnings) and a weaker one (second runnings)

Occurs to me that another neat thing you could do with BIAB is to produce two worts with quite different characteristics, but recombine them in the boil.


I'm intrigued by the idea of doing a high mash above 70 degrees in Alpha Amylase territory and collect that wort and segregate it, then a second mash down around 63 in Beta Amylase territory. I'm using half the normal strike water. Hoist and drain the bag and collect about 12L of strong and dextrinous wort. Heat this to nearly boiling to denature enzymes and run off into a holding vessel . There should still be heaps of goodness left in the mash as it hasn't been sparged out.

Then drop the bag back into the urn, in my case, top up with the other half of the water but mash this for an hour at only 63 degrees, with some extra malt to top up any beta amylase that may have been denatured during the first mash.

Hoist and drain the bag, bring the wort up towards the boil to denature enzymes and pour the first runnings back in and boil and hop as normal.

I'm aiming for a rich dextrinous beer that also has kick, interested to see if it differs in mouthfeel and maltiness from the same grain bill just mashed in the middle at 66 degrees.

Will report.

Timer sounding, gotta dash :party:

Post #2 made 4 years ago
Going suspiciously smoothly.

First mash is just base malt, and I've drained it into a container after mashing at 72 for 40 minutes

Second mash will have some extra base and the crystal malts added.

Note as the first mash is draining I'm heating up water for the second in my bucket o' death. :cool:

Second mash at 62 is now resting. Apart from some extra shuffling around the brew session shouldn't be much longer than usual. Looking forward to the results.

To reiterate: the idea is to increase the dextrins in the brew from the usual 20 percent or so up to (who knows, 30? 40?) but still generate enough simple sugars to ensure a full strength beer. So it will be both a dextrinous wort and a fermentable wort at the same time. It's actually quite a large grain bill for the batch size as I slipped in an extra kilo of base for the second mash.
Last edited by Beachbum on 15 Oct 2013, 12:23, edited 2 times in total.

Post #3 made 4 years ago
Looking forward to hearing your results BB.

That grain bill looks huge!

I always wonder with Alpha Amylase, being a "rogue" in nature (with it's randomness), whether you can get repeatable results?
What I am saying is, on one brew it might decide to "act all beta" and nip nice short molecules, then the next brew get lazy & leave long dextrinous molecules. Probably doesn't work like that in the real world though!

Off topic question, but what volume is that boiler?
I spent lots of money on booze, birds and fast cars. The rest I squandered
I've stopped drinking, but only when I'm asleep
I ONCE gave up women and alcohol - it was the worst 20 minutes of my life
    • SVA Brewer With Over 100 Brews From Great Britain

Post #4 made 4 years ago
It's a 40L electric urn. I don't bottle any more so I do a 23 litre total batch in the boiler, 27 litre initial boil, of which about 21 goes into the fermenter plus maybe a litre if I'm lucky that I salvage for doing yeast starters. I eventually end up with a Cornie sized batch on kegging day with a half pint sneaky taster :drink: .

I've ended up with an OG of 1055 and very keen indeed to see what the FG is going to end up at.

If I was just doing a "normal" mash, using Wyeast Irish Ale yeast I'd expect to end up at around 1010 that would yield a 5.9% beer - as you say it's a bigger than normal grain bill.
However if, as hoped, it ends up more like 1019 due to extra dextrins then it should yield around 4.7% which is what I am aiming for.

At my age anything over 5% is a nice quick hit but I can't drink too much otherwise I end up sobbing "Oh why did Princess Diana have to die?" :whistle: after a few more pints.

The whole brew day wasn't much more trouble than a normal one, and had plenty of time to tidy up and clean up the extra vessels during the boil.
Post Reply

Return to “BIABrewer Old Hands”

Brewers Online

Brewers browsing this forum: No members and 2 guests