Does Decoction Mashing Brew A Better Beer?‏

The secret ingredient in many recipes is said to be Love… and I want to believe that holds true in the brewing world as well…

I’ve read/heard so much about decoction mashing not being worth the effort as if brewing were a chore… I guess adding three hours to your brew day isn’t exactly refreshing, but what if it really makes a better beer? What if?

Well I’m about to take on my next experiment… does decoction mashing really produce flavors you can’t get with infusion mashing?

Today I’m going to take the side of YES to decoction mashing… next week I will take on the NO to decoction mashing and ways I’ve learned you can mimic the flavors of a decoction mash…

This will be a long experiment so let me start by telling you why I think decoction mashing can produce flavors you can’t get with infusion mashing…

It has to do with the grains you use and how you ‘cook’ them… I like to compare decoction mashing and infusion mashing with making oatmeal using steel cut oats and instant or even old fashioned oats…

Decoction is more or less like making steel cut oats… you have to cook the grains hard and it takes much much longer… infusion mash is more like cooking old fashioned oats… takes less time…

But if you’ve ever tried steel cut oatmeal and old fashioned oats you will find a very subtle nutty flavor and slightly different texture in steel cut oatmeal compared to old fashioned or instant oatmeal… and I want to think that this subtlety is similar to the subtlety that makes some of the finest German lagers stand out from other lagers…

So with decoction mashing, the goal is to take undermodified malt (think steel cut oats) and cook part of them really hard to burst the grain and allow enzymes in the main mash to work on the grains…

That’s the general idea, but let me back up for a second here…

In a decoction mash you start out by doughing in all your grains in the mash tun and making sure the pH of the mash and Calcium levels are appropriate… then you take a portion of the mash (thick meaning hardly any water, mostly grain) and place it in a separate pot. You then do a mini protein and starch to sugar conversion rest and then you boil the grains…

After about 30 minutes of boiling you take those grains and throw them back into the main mash… this takes the main mash from a dough in rest to a protein rest… Note that the first portion of the grains are going through a protein rest a second time… and that’s fine because it’s undermodified… if it were to be highly modified you’d be destroying your head forming and body giving proteins…

Anyways…

You then take a portion of the grains again and do a second decoction where you hold the grains at a starch to sugar conversion rest and then boil the grains for thirty minutes… when done the decoction goes back to the main mash for a starch to sugar conversion rest…

So far this seems like you are adding more work to your brew day when you can buy well modified malt and avoid all this boiling and decoction mumbo jumbo… but there is one thing that makes this somewhat unique…

Note that the grains are going through a starch to sugar conversion rest up to three times (in a double decoction as explained above)… but that’s not all…

In his book New Brewing Lager Beer, Greg Noonan says to hold the starch to sugar conversion rest in the decoction mash at higher temperatures (156 to 158 F)… But the starch to sugar conversion rest in the main mash is held at lower temperatures (149 to 152 F)… (*I lend my book to a friend so I don’t have the exact numbers he quotes, but just go with me for a sec)… this gets the alpha amylase and limit dextrinase enzymes, which work best at higher temperatures, to break down starches to sizes which beta-amylase can break down at lower temperatures in the main mash… and I believe it is this part right here which gives beers that extra malty kick…

In order for this to work I believe you have to be precise and very accurate with your temperature and time readings… and this isn’t exactly easy to do…

This is where process makes a huge difference… and I don’t think anyone should be chiming in on whether decoction mashing is better or not… The reason why I haven’t been satisfied with any answers I’ve found online including famous radio shows is that the people who were not too fond of decoction mashing didn’t seem to be experts or even good at it… they only did a single decoction or didn’t seem to have the practice needed to do this right…

In his book Brewing Better Beer, Gordon Strong does say that he believes decoction mashing does make a difference… he won Ninkasi three times, so I think I’ll pay attention to what he says…

So my goal for the year is to brew pretty much nothing but beers traditionally brewed with decoction mashing until I can say I’ve brewed enough of them without any hiccups (basically master decoction mashing) and then compare the best samples with beers I’ll brew using regular infusion mashing (step mashing to be more exact)…

So next week, I will write about how I plan on getting the same results while completely avoiding the gruesome decoction process… and to make sure I don’t miss anything, let me know what you think about both pros and cons…

2 Comments

  • Jim Hay

    Reply Reply October 2, 2012

    You’re a step ahead of me with deciding between YES and NO to decoction process. My plan is similar in that I was going to use the exact recipe, but try infusion mash, then compare.
    I am fermenting my 1st lager and decocted the grain. It was a chore, but I reason it so because of my virginity. The next time should be less painful, but IF it’s not necessary I would prefer to stay with infusion.
    I am very interested in your findings!

    Cheers!

    Jim

    • Jorge

      Reply Reply October 3, 2012

      Jim,

      One thing about these experiments is that they lead to more questions… I have learned a lot from doing decoction mashes and have a few theories that developed from that…

      Does decoction mashing make a difference? Absolutely
      Is it necessary?

      It depends…

      Decoction mashing goes beyond flavor development…

      Decoction mashing produces maltier beers because of the sugars produced during decoction, but that’s not the only reason to decoct… Sometimes it’s necessary for adjuncts…

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