Decoction mashing and calculator

Anybody have a favorite decoction calculator? I'm brewing a Vienna this weekend and wanted to try a relatively simple 2-step decoction, then I'll do a 3-step decoction on my next Pils.

Here's the tentative plan with a couple of questions thrown in (bleed all over this if you find mistakes/problems/etc.):
14 qt. water
9.5# grain
Should I make the mash looser?
First rest at 133o F for 20 minutes.
Do you immediately pull the first decoction or do you let the entire mash rest at this temp for a while and then pull it?
Pull thick decoction and increase to 150o F and rest for 30 minutes.
Increase decoction to boiling and boil 10 minutes.
Add decoction back to mash and mix well.
Rest for 40 minutes @ 150o F and test for conversion.
Pull thin-mash decoction and increase to boiling and boil until hot break.
Add thin-mash decoction back to mash to get mash-out temp (170o F).
Lauter/Sparge as usual.

Note: Regarding my rest temps...I went with some numbers from Designing Great Beers but went with a 2-step decoction for simplicity. The 150o F saccarification rest might seem low but...that's allegedly what the 'real' Vienna brewers saccarificate D) at. And according to Daniels they pulled a thin-mash decoction for the last decoction and boiled it until hot break before adding it back.

I just dunno how much to pull and how hot it needs to be to get to the correct temp for the next step.

I use the calculators at tastybrew.com. They have always worked for me. For a decoction mash though, I usually just do a single decoction about forty-five minutes after mashing in at infusion temp. I take about 40% of the mash out (very watery rather than thick), slowly bring it up to 160 degrees. I lleave it at 160 for twenty minutes and then slowly bring it to a boil and boil for around 30-45 minutes. I add that back in to the MLT, let it sit for ten minutes and then batch sparge. It works for me and is kind of a lazy man's decoction. I just did it on e hefeweizen that I brewed over the weekend and I always do it that way on my dunkelweizen. According to several sources, the important part is the length of the boil on well modified grains rather than the number of decoctions.

Your mash thickness is OK, but you could go even higher, like 1.75 to 2 qts per pound. I think the 2-step will work great, but with those temps, that will attenuate very well, if that's what you're looking for. Remember that 133°F rest is a combination protein and saccharification rest. Then, you're going to a full saccharification rest. You might consider raising that to a dextrin rest in the mid 150's°F (this would be the same for your decoction rest temp).

Before pulling your first decoction, let the mash sit for ~5 minutes, then pull it. I think holding your first decoction at the sacch. temp for 30 minutes is a bit long. You could do fine with 10 min., then boil for 5 min. Then you could let the mash rest in it's new temp for 20 min. instead of 30. This is what I do and they always turn out great. It might shave some time off your brew day.

I use Beersmith. The decoction rest temps have been dead on. Highly recommend it.

So are you just doing a decoction to mash out? (That was to RayinUT)

I also use the calculators at TastyBrew and I don't see any decoction calculators at TastyBrew. They have infusion and strike calculators but that doesn't really help when you're adding both grain and water back into your mash (which of course has been 'thinned' because you pulled a decoction from it). Then there is the issue of; "How thick is the decoction?".

BTW, the Full Recipe Calculator at TastyBrew has a little 'bug' in it that becomes evident when you play around with a brew that has SRM right at 8. They actually change the method for determining color at SRM=8. So if you make a brew that has SRM=7.5 thru 7.9 you'll get SRM=8 in the display...but then if you add a tiny bit of dark grain to get a darker beer the returned number >8 so they change methods and the new method will return something like SRM=6 or 7. So you added dark grain but your SRM went down?!? Just a little bug in it that I found. I encountered this and e-mailed them and that's what they said.

Thanks mensch. I chose the low sac rest temp because that's what Daniels says the Vienna brewers do...it was actually 149o F in the book and fairly consistent across several brewers. I assume because Vienna lager has such a high amount of Vienna/Munich malts and the goal is malty but still with some dryness that that's why...just a guess.

Thanks for the tips...I'll loosen the mash a little and then shorten the decoction rest and boil...then test for conversion pretty early on. You think I should lower the protein rest to 122o F?

SpanishCastleAle said:

You think I should lower the protein rest to 122o F?

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No, I wouldn't do that. You'd probably loose head formation/retention in the final beer. I'd stick with the 133°F.

SpanishCastleAle said:

So are you just doing a decoction to mash out? (That was to RayinUT)

I also use the calculators at TastyBrew and I don't see any decoction calculators at TastyBrew. They have infusion and strike calculators but that doesn't really help when you're adding both grain and water back into your mash (which of course has been 'thinned' because you pulled a decoction from it). Then there is the issue of; "How thick is the decoction?".

BTW, the Full Recipe Calculator at TastyBrew has a little 'bug' in it that becomes evident when you play around with a brew that has SRM right at 8. They actually change the method for determining color at SRM=8. So if you make a brew that has SRM=7.5 thru 7.9 you'll get SRM=8 in the display...but then if you add a tiny bit of dark grain to get a darker beer the returned number >8 so they change methods and the new method will return something like SRM=6 or 7. So you added dark grain but your SRM went down?!? Just a little bug in it that I found. I encountered this and e-mailed them and that's what they said.

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Sorry, I use the calculator for the infusion temp and then go with Palmer's decoction chart on page 172 of How to Brew using the single decoction. It's easy and I promise you won't be able to tell if you did a single or double decoction other than the fact that you saved a bunch of time and didn't have to worry about hitting your sacc rest properly. You already have conversion at this point, you are just getting the flavor and body.

Thanks for the responses.

It's easy and I promise you won't be able to tell if you did a single or double decoction other than the fact that you saved a bunch of time and didn't have to worry about hitting your sacc rest properly.

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I appreciate your input Ray and I see where you're coming from but...if it was about saving time I wouldn't be homebrewing at all. And I certainly wouldn't be doing any decoction mashes.

I don't see any decoction chart on the online version of How To Brew. But I want to do more than just mash-out with a thin-mash decoction...to me that barely qualifies as a decoction mash. I don't think hitting the sac rest temp will be that much of a problem because my sac rest temp is only 150o F...so if I over shoot it's not that big of a deal and if I undershoot and I can always add heat. But I was hoping for a calculator to at least get me close...there are a couple I tried but they didn't give the same answers.

FWIW, I checked Designing Great Beers again last night and the rest temps for the 3-step decoctions averaged around 95oF-122oF-149oF. So they used the 'classic' acid-protein rests and then a low sac rest. I'll just use slightly softer water and skip the acid rest.

RayInUT said:

I promise you won't be able to tell if you did a single or double decoction other than the fact that you saved a bunch of time and didn't have to worry about hitting your sacc rest properly. You already have conversion at this point, you are just getting the flavor and body.

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Don't make promises you can't keep. IMO, if you're only going to decoct to mash out, you might as well not decoct at all if you have another way to reach mash-out temps. Mash-out decoctions are really just for temperature infusions.

All the texts I've read say that single decoctions are to go from protein/sacch. rest to sacch./dextrin rest. You don't get enough maillard reactions and other quality wort compounds after conversion and with a thin decoction.

SpanishCastleAle said:

FWIW, I checked Designing Great Beers again last night and the rest temps for the 3-step decoctions averaged around 95oF-122oF-149oF. So they used the 'classic' acid-protein rests and then a low sac rest. I'll just use slightly softer water and skip the acid rest.

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Keep in mind, those temps are somewhat historic and more for commercial brewers. Each temperature has it's own purpose and it's own reasoning and should be looked at individually to see if it would be damaging to the final product.

The acid rest... water is the focus there. If your water pH is relatively low, you don't need it, but it couldn't hurt to do it.

The protein rest... this is the big one and can tie into the saccharification rest. European commercial brewers who still do this use malt that isn't so highly modified and has a relatively low soluble nitrogen ratio (SNR). For example, I'm not sure of the exact temperature, but Moortgat (Duvel) does a true protein rest. But they use several different pilsner malts with specified modification (the maltsters modify it to their specs) and most, if not all of it, is much less modified than malt that is available to homebrewers. Most malt we buy has a SNR above the recommended limits for doing a true protein rest. The result would be decreased head formation/retention. A good compromise is doing a rest somewhere in the 130's because it's high enough to avoid the negative effects of a true protein rest with a high-SNR malt.

The saccharification rest is more or less how we we've always thought of it... how attenuable we want the wort. But remember, if you do a "protein" rest in the 130's, you're also getting some saccharification. So, most schedules I've seen with a 130's rest put this rest into the mid 150s, which then becomes more of a dextrin rest.

Thanks mensch...very good explanation. I do intend to use less alkaline water for this (I said 'softer' above but really meant 'less alkaline') so I can skip the acid rest.

Does Vienna malt have too high SNR for a true protein rest? This Vienna lager is almost all German Vienna malt with some German Pils and some German Munich and just a little bit of Crystal. It's all Weyermann (except the Crystal which is Briess)...I thought the German malts were less modified?

Here is one that I use...Calculators. The single decoction that I use works for me. I've done double and triple decoctions and I don't believe there is a difference if the malts are well modified. As I said before, I think the key is in the long boil, not the number of decoctions.

Thanks Ray...I did try that one. We'll see how it works this weekend.

IMO, depending on the equipment/ingredients/water/process and probably a host of other things...something that might not make a noticeable difference on my brews might make a very noticeable difference in yours.

Also FWIW, in the DGB book the decoction boiling times were 30 minutes minimum for a Vienna...45 minutes minimum for a Marzen/Octoberfest. I would think you would have to boil these things for at least some appreciable time to get the full benefit (but I'm just guessing).

SpanishCastleAle said:

Does Vienna malt have too high SNR for a true protein rest? This Vienna lager is almost all German Vienna malt with some German Pils and some German Munich and just a little bit of Crystal. It's all Weyermann (except the Crystal which is Briess)...I thought the German malts were less modified?

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Today, the malts that homebrewers get are well modified, even from Germany. According to Weyermann's website, the Vienna malt (your "base" malt) ranges from 36 to 45.5 SNR if I'm reading it correctly and that sounds about right. I'd play it safe and do the higher protein rest temp.

I know this is a really old post, but how did it go. i'm sure you've brewed dozens of decoctions by now. what have you settled on. specifically for a vienna lager?

Just my two cents from someone who just completed their first decoction mash a couple weekends ago.

First, I used beersmith for decoction volumes, and came up shy when remixing to make the step temp. I had to use boiling water to bring it up to where I wanted it, and subtract this from my sparge volume. When I do it again, I would add about a litre or two to the decoction volume that beersmith advises.

Second, and related to the first comment, I remember on brewing TV that Dawson advises to pull one quart thick mash per pound of grain. This is much more than what I pulled, but it does give you an idea that everyone has a preference on how much to pull. Remember, more is better than less. If you pull too much, and when remixing you have some left over, then just let the temp drop and add it back to the mash when it is close to the mash rest temp.

Third, I would suggest to use a mesh strainer to pull the decoction. This allows you to get the thickest part very easily. Then, when you have 'almost' enough volume, add some mash water to thin out the decoction and add the necessary extra volume. I tried to have about 3/4 inch 'thin' mash water above the grain in the decoction.

Lastly, unless your decoction pan has volume markings, make some on a piece of wood or something so that you can easily determine the volume of the decoction.

Hope this helps!