Step v Decoction

So I've looked through forums & several of my books and cant quite come up with the discussion I'm looking for. Could any one point me to a source that would discuss the diffrences in final product that would result from step mash vs decoction mash with the same recepices? I've recently upgraded my system to make both possible and want to start experimenting with them. I know decoction is traditional to a lot of German styles, and that step mashes are used for sac rests and such, but what happens if you hit your decoction target temps via direct heat & not decoction?

Decoction was pretty much invented, or at least first used as a brewing technique, out of necessity when performing a step mash because without an accurate thermometer the temperature changes caused by boiling a portion and adding it back are predictable whereas applying heat to hit your steps is not.

Obviously the difference is whether or not you're boiling a portion of the mash to achieve the next mash step. Thus, you're simply performing a step mash if you don't decoct a portion of the mash.

So then you have to look at what the boiling does. The answer is twofold.
One, the grains that are boiled become more broken down than the grains in the mash. This alters the extraction of all sorts of compounds.
Two, it gives more opportunity for Maillard reactions to take place.

These two things will create a uniquely malty flavor in the final beer that cannot be achieved with a step mash alone.

Dsm:
Try JJPalmer's 'How to Brew'
VERY good book, usaually ~$20, saw it on Amazon few days ago for $9. Even w/ shipping, a bargain.
He discusses both methods.

AlCophile said:

Dsm:
Try JJPalmer's 'How to Brew'
VERY good book, usaually ~$20, saw it on Amazon few days ago for $9. Even w/ shipping, a bargain.
He discusses both methods.

Click to expand...

The first edition is also available for free at howtobrew.com

Specifically, the chapter about mashing is here

I may be wrong but I will do my best to describe the difference based on what I know and have done.

Step mash's raise the temps of the grain by either adding boiling water or by means of heating the mash to raise temperatures to the desired range. Simple and effective.

Decoction mash's raise the temps by pulling of a portion of the mash and bring that to a boil, then adding it back to the mash to effectively raise the mash temps. By boiling the mash you are effectively caramelizing a portion of the wort and adding that back to the mash to help sweeten, darken and add complexities to the mash. I have read that some people actually pull of grain as well as wort in the decoctions and boil that together. One of the reasons I don't like this is when you raise the grain temps over 170 degrees you release tannins and could run the risk of astringent tasting wort. The way that I do a decoction is I just pull off the wort and boil that (with no grain) to try to avoid the releasing of tannins from the mash.

I have not done a side by side on beers yet but I plan on it as I make a really good bavarian Hefeweizen with a triple decoction mash. I now use a herms set up and wanted to see if I can get the same results by just doing step mash's instead of the decoction.

By the way, you will see the words double decoction or triple decoction alot when looking into decoctions. All that means is how many times you pull off wort, boil it and add it back to the mash to raise the temp.

Go to Brau Kaiser's site, excellent information. I don't know how much decoctions add flavor, as I haven't done it side by side, but it definitely increases your sense of working your beer...if you want to add "mash interaction" decoction is fun and interesting, if you'd rather an easier brewday, step mashes will probably produce 90% of the decoction procedure, from what I have read.

I think it is almost more tradition than flavor, maybe someone who has done true side-by-sides can comment. Most Germans don't even do decoctions any more, yet the Germans I had were fantastic.

TahoeRy said:

I have read that some people actually pull of grain as well as wort in the decoctions and boil that together. One of the reasons I don't like this is when you raise the grain temps over 170 degrees you release tannins and could run the risk of astringent tasting wort. The way that I do a decoction is I just pull off the wort and boil that (with no grain) to try to avoid the releasing of tannins from the mash.

Click to expand...

It's not just some people, a decoction should be very thick. When you pull it off, and put it in your pot for boiling you shouldn't see any wort above the top of the grain.

PH is the most important factor in tannin extraction, followed by temperature. PH alone can (slowly) start to extract tannins without high temperatures but temperature by itself really doesn't do too much. As long as your mash PH is correct, you don't have to worry about tannin extraction at high temps.

"The way that I do a decoction is I just pull off the wort and boil that (with no grain) to try to avoid the releasing of tannins from the mash."

Depending at one point of the process that you are boiling the mash water, you can denature enzymes. The time when the mash water is boiled is after conversion and it is used to raise the temp to mash out.

Even though the grain today is high modified, low protein and for that reason many say that a decoction isn't needed. There are other things that occur in a decoctioned mash. The boiling reduces the small white starch material that isn't turned to flour during the crush. Allowing the enzymes to get at those starches easier. The boiling produces minerals and chemicals that the yeast will benefit from. The boiling breaks the surface tension of the mash water and makes the water "wetter" allowing it to flow through the grain bed better. Hot break and cold break materials are lessened in a decoction. The quality or quantity of wort from the best infusion or step mash process will never match that of a decoction.

Thank you all. This is exactly the kind of discussion I was wanting. I'm going to be working on some side by side step v. decoction batches in hopes of learning more about the differences. Any suggestions for recipes?

I started this thread today under brew science:


"My disclaimer: I don't know what I'm talking about BUT I think this makes since. Can someone who DOES know comment on the science here.

After reading numerous variations on decoction this is what I have concluded based solely on the science as I understand it.

Multiple decoctions are pointless. A single decoction adding the grain back for the second rest only after you reach your desired grain "cereal" consistency, breakdown, and color is all you need. After the first decoction rest and addition of all your removed grain, simply increase you mash tun temps as a stepped mash method to reach your desired resting temps.

As I understand the science, the resting temps are based solely on the reactions happening in the mash tun, bringing the cereal to boil multiple times does nothing any different than bringing it to boil once for a prolonged time. Breaking down the cellular structure of the grain is all you are really accomplishing, aside from altering flavor and color which can be accomplish in one boil as well.

This method would allow a much less labor intensive process for a multiple decoction recipe.

Anyone with knowledge here care to comment?"