Decoction for a dunkelweizen

[orford]

Greetings all,

I am planing on making a dunkelweizen this weekend. I was going to use my normal hefeweizen recipe (60% wheat, 20% Pils, 20% Munich) but use a double decoction mash to get the color and caramel flavor needed. I have a couple of questions. Was going to dough in for a protein rest, elevate to saccharification, then elevate to mash out.

I have done a single decoction in the past for a double bock and saw only slight color changes, will a double decoction get me the color I am shooting for (SRM of 20 or so)? I was thinking a 30 minute boil for each decoction.

A lot of people include a saccharification rest in their first decoction at 158F. This seems a bit high, would it not make more sense to rest at 152 on the way up to the boil?

Many thanks,
Dan

 

[Cyclman]

Pilsners can be double or triple decocted, so it won't give you roasty or dark colors / flavors.

 

[orford]

I realize that many Pilsners are decocted but my assumption was that these decoctions were for very short periods of time hence little to no color change. My thought was that a longer decoction will increase the time for Maillard reaction and hence darken the beer. In theory two long decoctions, say 30-45 minutes a piece will yield a darker product. Perhaps not...

 

[orford]

As an update this was probably the longest brew day I have ever had. Everything that could have gone wrong did. My thermometer broke during the initial acid rest... I ran out and bought a new one, got home and measured the temp of the mash. It had gone up ~10 degrees... Turns out the thermometer was broken too (it told me I had a temp of 112, I was admittedly angry but not that fuming!). So I ran out again for another one... I set up the first decoction and that went smoothly but when I added it back I did not hit the protein rest temp so I had to pull some more off and quickly boil. Same thing happened for the next decoction, did not pull enough thick mash and missed my temp... As I got close to mash out I realized I did not have the color I needed so I tossed in 0.5 LB of chocolate malt. Also, this was the second time I used my new ales bottom in my mash tun and I got a stuck sparge, first time ever...

All that being said, the final product, though a bit light in color for a dunkelweizen, is fantastic. My wife who is German, said after drinking it the first time "this is a weizen beer. This is what people drink in Germany!" I will take that as a good thing. The chocolate did not add any real bitterness, just some color and a really subtle roast flavor. Fermentation temps were good so we got more off the clovey phenols and less of the fruity esters.

Would I use decoction again; yes. Why? I love to brew and the mash is one of my favorite parts. If I have the time why not? Does it make a difference in color? I would argue it is marginal at best. I think it does impact flavor as this beer is probably one of the best hefeweizens I have made to date. Mind you this was not my first decoction and I do not think my last.

 

[VladOfTrub]

"A lot of people include a saccharification rest in their first decoction at 158F. This seems a bit high, would it not make more sense to rest at 152 on the way up to the boil?"

Not necessarily. Each temperature step during the process is related to the next step upstream. At 158 conversion of the 1st decoction, the next step has to be considered, the mash pH has to be considered, too. The pH of the 1st decoction will be higher than the pH of the 2nd decoction. The differences in the pH affect both enzymes in a positive way. The higher pH of the 1st decoction favors alpha amylase. Hence, a rest at a higher temp of the 1st decoction. The higher temp allows the alpha enzymes to chop up the long chain starches for other enzymes to start to convert. Now, here's why the upstream temps come into play. Once, the 1st decoction is dumped into the main mash to reach protein/diastatic rest temps. At the temperature of that rest, conversion will begin to take place. Even though the starches haven't been gelatinized in the main mash, the enzymes will still convert the starch to fermentable sugar. Dextrinase and maltase do the converting. The enzymes can reduce the "Y" branches of the starch chain to fermentables. Those enzymes along with beta amylase favor the lower pH and lower temperature of the mash during the protein rest. So, the brewmaster knowing that fermentables are being created during the protein rest, will offset them with a-limit dextrins created at 158F in the 1st decoction. I read many posts on here where brewers are hooked on a short 131F rest due to using high modified malt. One line from a hundred page text is being looked at, without regard to the entire text. Each temperature step during the decoction has to be linked to the previous step or the next step upstream. It's not random temperatures. The higher the temperature of the protein rest, the higher the temp of main mash conversion has to be and vice versa. A main mash conversion at 158F favors the 131F protein rest. If you are going to get into decoction mashing, you'll need the equipment to make it easier. A seperate mash tun that can be direct fired is a great benefit. It is better to pull a little less decoction than too much. With a direct fired mash tun, temp maintenance is a breeze. Pulling too much mash during the decoction changes things quite a bit. If you investigate recipes from German brewmasters, you will notice that they will use as many as five temperature rests. Depending on what they are brewing.