Easy Single Decoction

Brewsmith · 06-01-2006, 09:51 PM

For all you advanced AG'ers out there, I want to try a single decoction on my next hefeweizen brew coming up. Anyone have a good tried and true method including water/grain ratios, temps, and amount pulled out for the decoction?

**Baron von BeeGee** · 06-01-2006, 10:26 PM

For a single decoction I think you'll get the most bang for your buck with a protein-saccharification type of schedule. What I would do is take whatever recipe you want and mash in to get ~122F at 1.5-2qt/lb mash ratio. After ~15 minutes take out 40% of the thick mash (I use a colander with a handle and scoop it into a 1qt container), put it in your decoction pot, and slowly raise it to ~150F. After 10-15 minutes slowly raise it to boiling, boil for ~10 minutes (not too long for a Hefeweizen), then return to the mash. Check the temp of the mash and adjust to ~150F. Once a conversion test is negative, mash out.

If you're so inclined, you could try my last Hefeweizen mash schedule which went something like:
Infusion to 104F acid rest (I'll have to check my notes on the exact temps)
Infusion to 122F protein rest
Thick decoction to 150F saccharification rest
Thin decoction to 170F

At least I think that's what I did...I'd have to check my computer at home. The acid rest really seemed to do the trick for the flavor of this recipe, unless it was due to something else I didn't account for. An acid rest will generate ferulic acid, the precursor of 4-vinyl guaiacol which gives the Hefeweizen its distinctive flavor. But you will get some ferulic acid, anyways, so this is only if you want to go over-the-top like the Kaiser and me. It will also give the mash a chance to hydrate really well which may help with mashout. When I did this schedule I achieved 78% efficiency whereas I've never gotten above 72% with a wheat-based grist before (more like 65-70% usually).

The thin decoction at the end is really no more difficult than infusing with boiling water to reach mash out.

Brewsmith · 06-01-2006, 10:44 PM

Sounds great. That's exactly what I was looking for. I have several books that mention decoction mashes, but it always seems easier when someone else describes their method. Also, some of the books are vague about amounts, since a microbrew might be using the same info. Thanks. I'll probably stick with the single this time, although the other method doesn't seem too much more difficult. My mash tun is only 5 gallons, which makes several infusions difficult due to space.

**Baron von BeeGee** · 06-02-2006, 01:07 PM

Here's a pretty good link which details the process fairly well IMO:

http://www.strandbrewers.org/techinfo/decoct2.htm

He recommends pulling 33%, I believe, but I usually pull a little more for a safety margin. Also, for a HW, I wouldn't boil longer than 10-15 minutes for fear of darkening the wort too much. For a darker beer you can boil 30-45 minutes. Finally, I can't remember if he recommends stopping at 150-155F for a short saccharification rest in the decoction pot, but I've been doing it as it's mentioned in all the literature I've read on how German breweries do their decoctions.

Kaiser · 06-02-2006, 01:44 PM

Quote:

Originally Posted by Baron von BeeGee

He recommends pulling 33%, I believe, but I usually pull a little more for a safety margin.

I use Beersmith to calculate the decoction amounts and add 2-3qt to that amount to account for boil-off and lower actual temp of the main mash.

Kai

cweston · 08-10-2006, 01:52 PM

Quote:

Originally Posted by Baron von BeeGee

Here's a pretty good link which details the process fairly well IMO:

http://www.strandbrewers.org/techinfo/decoct2.htm

He recommends pulling 33%, I believe, but I usually pull a little more for a safety margin. Also, for a HW, I wouldn't boil longer than 10-15 minutes for fear of darkening the wort too much. For a darker beer you can boil 30-45 minutes. Finally, I can't remember if he recommends stopping at 150-155F for a short saccharification rest in the decoction pot, but I've been doing it as it's mentioned in all the literature I've read on how German breweries do their decoctions.

Do you mean stopping for a short rest at 150-155 in the process of bringing the decoction mash to a boil?

That link was very helpful, BTW.

Exo · 08-10-2006, 05:50 PM

I'm very confused about this. Excuse the "stupid" question, but if you boil your grains won't your brew take on the tannins of the grain husks?

cweston · 08-10-2006, 06:17 PM

Quote:

Originally Posted by Exo

I'm very confused about this. Excuse the "stupid" question, but if you boil your grains won't your brew take on the tannins of the grain husks?

I'm not really sure about this, but I think that this is why you do a thick decoction--the relative lack of liquid in the decoction pot keeps it from drawing tannins out of the grain.

Exo · 08-10-2006, 06:22 PM

Hmm, that makes sense. But still, some tannins have to end up being extracted.

Doing two batches of the same ingredients with one using a decotion and one using flame under the mash/lauter tun....would the end product be slightly different?

**Baron von BeeGee** · 08-11-2006, 03:04 AM

It seems like it would, but in fact tannins won't be an issue in the slightest with a properly executed decoction. The two factors that are necessary for tannin extraction are high temperature and high pH (above 6 as I recall). If your mash is in range (pH) at all, then you won't have a pH situation in the decoction that will allow tannins to be extracted.