[theoman]

Has anybody ever tried doing two mashes at different temps for a single beer? Maybe you want more alphas from one grain and more betas from another. I think it could be fun to play around and get possibly interesting results without adding time to the brew day or being annoyed with missing temps on a multi-step mash.

[nateo]

I do two mashes whenever I do decoctions. Pull the decoction and raise to a sacc. rest before boiling. IMO it's harder to manage two mashes than to just do step mashes, which would give you basically the same results as what you're describing.

Alpha- and Beta-amylase ranges are a sliding scale, not an on/off switch. The only reason I could see doing two separate mashes, instead of just finding the right spot on the temp scale to mash at would be to have two different mash pHs or something like that.

[richardt]

Or you could just gelatinize all the starches and add the necessary exogenous enzymes.

http://www.biokemi.org/biozoom/issues/522/articles/2368f

But, where's the fun (and craft) in that?

[denny]

I'm kinda at a loss trying to figure out what advantages there would be to it.

[nateo]

I'm kinda at a loss trying to figure out what advantages there would be to it.

I think it's kinda like "triple hops brewed."

[denny]

I'm kinda at a loss trying to figure out what advantages there would be to it.

I think it's kinda like "triple hops brewed."

 

[Jimmy K]

I'm kinda at a loss trying to figure out what advantages there would be to it.

Some people like complicated

[theoman]

Hm, far less useful responses than what I would expect from this board. Complicated? Here's what I'm picturing:

Two brewers working on a 60 minute mash:

60 min:
Me - Water on one bunch of grain for 62 (I'm going metric here guys) degree mash. Wait for water to warm up for 68 degree mash on second bucket of grain.

Other guy - All water on grain for 62 degree mash.

40 min:
Me - Dump water on other grain for 68 degree mash. Stir.
Other guy - pull grain to boil for decoction.

35 min:
Me - Drinking beer
Other guy - "When will this damn thing boil?"

30 min:
Me - Drinking beer
Other guy - hoping his grains don't burn.

20 min:
Me - Drinking beer
Other guy - "Oh, crap! Missed my target temp again!"

10 min:
Me - Sanitizing my fermenter and hoses while drinking beer.
Other guy - "C'mon water, boil! I need to hit this temp somehow!"

0 min:
Me - Dump grains together and sparge.
Other guy - "I should've gone single infusion."

Now that that's out of the way, are there any good (ie technical) reasons why this is a dumb idea?

[nateo]

Now that that's out of the way, are there any good (ie technical) reasons why this is a dumb idea?

Well, I guess what I was saying wasn't clear. here's what I was getting at: http://beerbarons.org/pdf/brewingCheatSheets/mashRests.pdf

(temp range / optimum)
Beta Amylase: 52-68/60-65 C - fementable sugars
Alpha Amylase 54.5-77/68-70 C - dextrins, long chain sugars

So if you have one mash at 52*C you'll pretty much only get beta activity (let's ignore the proteinases for now). If you have another mash at 70*C you'll pretty much only get Alpha activity. Temperatures between these ranges will have different enzymatic activity proportional to how far from optimum the mash temp is.

Alpha and Beta are complementary enzymes. They need each other to produce a proper wort. Think of it like making firewood. Alpha cuts down the tree, Beta cuts the tree up into logs. One won't work without the other.

Separating the mash into two mash at different temperatures could make one mash highly fermentable and one mash highly unfermentable, but you could get the exact same ratios of alpha and beta activity in a single mash.

(EDIT: now that I wrote that, I remembered a highly fermentable "reverse" mash schedule where the mash it taken to 160*F and slowly backed down to 140*F to get a highly fermentable wort. So I don't think just mashing below alpha range would actually make a fermentable wort)

The only time I could see doing two mashes would be when using, say undermodified wheat malt and overmodified British malt (Maris Otter/Golden Promise), where the wheat malt needs some protein/beta glucan work, but the proteins in the rest of the grain bill would be too degraded by extended low temp rests.

[denny]

The only thing that makes it a "dumb idea" (your words) to me is that I see absolutely no logical reason to do it or any gain that would come from it.

[richardt]

Cereal mashes for unmodified grains (or those with high gelatinization temps).  Classic American Pilsners need it for the corn starch gelatinization/conversion.

Beer-Making Corporations that are interested in maximum efficiency utilize high temps and exogenous enzymes.

Your example may be less effort than a decoction, but you'd still need to mix the two mashes back together and allow it to sit for awhile (20-40 minutes, I'd guess) for the enzymes to interact with the wort and grains of the fellow mash.  That takes considerable effort there.  Plus, the receiving vessel needs to be big enough to hold both mashes.

If you just lautered and sparged and let the combined wort sit for 20 minutes or so before heating above 160F, you'd continue to have some conversion taking place in the BK, but would not gain any further efficiency since the enzymes are no longer near the grains.

I just don't see the benefit (time or effort), and there may be detrimental effects (thin body, less dextrinous wort) on the beer (depending on style).

If you're looking for an easier brewday and/or maximum efficiency, I'd just gelatinize everything (protein rest and/or mash higher) and throw in extra amylase in the mash when it cools back down around 145-150F.  Personally, I don't think it will taste as good (tannins above 170F, thin bodied beer).  You can buy those types of beer already.