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The protein rest

PostPosted: Tue Dec 27, 2011 7:54 am
by EnglishBrew
I've been reading that doing a protein rest on modern well-modifed 2-row is a bad idea because the malting process has already done most of the protein breakdown that a p-rest is supposed to do. And that the p-rest actually takes it too far, breaking down too much protein resulting in watery beer. Of course the Internet is full of conflicting argument, I'm wondering if anybody has any experience. Im planning on making a pilsner through decoction mash this weekend, and to honor all Internet opinion will do a high-temp and short protein rest (135f for 15 minutes) then do a double decoction (144 and 154f rests).

PostPosted: Tue Dec 27, 2011 8:05 am
by aleguy
While it is true that modern malts do not need a protein rest, they are still necessary for the proper flavor development of some wheat beers, since the particular yeasts involved need excesses of certain chemicals to make their spicy character.
For a straight pilsner, I would think that a single-devotion, two-stage sacharafication rest would be adequate for the flavor profile you are looking for.

PostPosted: Tue Dec 27, 2011 8:10 am
by EnglishBrew
Yes. I did a 125f 30min protein rest then double decoction on an American wheat last week (70pct barley, 30pct wheat) and preliminary results are it's nicely wheaty and awesome. Another couple weeks before it should be carbonated.

PostPosted: Tue Dec 27, 2011 8:47 pm
by GuitarLord5000
I've done a few decoction mashes with short protein rests (on the order of 5 to 10 minutes) and have never experienced any problems with head retention. Even on beers that didn't include starchy wheat or rye malts. I don't believe that a protein rest is really necessary unless using starchy adjuncts, though. I also don't believe I'd feel comfortable doing a 20 or 30 protein rest on any non-adjunct beer, but I've never tried it before, so...

PostPosted: Wed Dec 28, 2011 6:33 am
by EnglishBrew
I did some more research and it seems that unless you're going out of your way to get undermodified grain, or have at least 30pct wheat in the grain bill then you shouldn't protein rest. The most important stat for protein in malt is the s/t (a nitrogen to protein ratio), which if it's over 38 the malt is considered well modified and shouldn't be p-rested. The pacific nw 2-row that most of us use is 44.5, which is at the limit of how well modified grain can get without having problems with body and head retention even with single infusion. Weymann's pilsner 2-row is down to 38, and even then on their website their recommended mash schedule for a lager is a couple step decoction that skips the p-rest (100f acid/ 150f sacc/ mash-out).

Anyway, the whole point of this is I want to boil some decoctions because there's still a persistent camp that says you can't get the right german lager profile without boiling some mash, plus I think it's cool. So it seems that with mash steps that avoid the protein rest I can still do it.

PostPosted: Wed Dec 28, 2011 3:35 pm
by GuitarLord5000
EnglishBrew wrote:...there's still a persistent camp that says you can't get the right german lager profile without boiling some mash.


I'm firmly in the decoction camp. Most of the beers I've made have included at least one decoction step. My opinion is that if you really want that great malty german lager flavor, you need to pull three large-ish decoctions with each being boiled for a minimum of 30 minutes. I've found that a single decoction mash doesn't really add much flavor contribution. It's a bit intensive the first couple times you do it, but after you get the hang of it it's not really much more difficult than infusion mashing. Takes longer, though.

Good luck!

PostPosted: Wed Dec 28, 2011 6:02 pm
by EnglishBrew
I'm going to do a 100F acid rest, 39% decoction to get to 140F, then 23% to get to 154F. I'm planning on getting out of the 100F rest as fast as possible cause I heard some stories about mash infections happening below 120F.

This is the culmination of 2 experiemental decoction mashes, if anybody wants to check it out this Saturday give me a PM.

PostPosted: Thu Dec 29, 2011 12:04 am
by aleguy
Mash infections? You don't need to worry too much. Anything per-boil will die and there's not enough time during a mash for bacteria to make any appreciable difference in the flavor of the finished beer. You would have to hold your mash for days for a mash infection to be noticeable. Don't worry, relax, have a home brew!

PostPosted: Thu Dec 29, 2011 12:45 am
by GuitarLord5000
Yeah, I wouldn't worry about mash infection. You'd have to leave your mash at those temps for quite a while, a la sour mashing, to have noticeable souring of the final product.

I do a similar decoction regime on my oktoberfest, except that I add a third decoction (liquid only, no grist) at the end to bring the mash up to mash out temps.

PostPosted: Thu Dec 29, 2011 8:31 am
by EnglishBrew
Greg noonan talks about acid rest infections in the lager book, but then again he says lots of stuff, and little about protein resting modern malts ruining your beer.

Yup, I was going to do a mashout.

I got pretty sick last night, brew day might move to Sunday if I'm slow to get over it.