Scorched Decoction

[roger_tucker]

I did my first decoction mash yesterday. It never goes right the first time does it? First of all I got a little scorching. I stirred constantly but I got a little burning regardless. Maybe I applied a little too much heat. The biggest spot was about 2-3 inches in diameter. I had 2 or 3 other spots that were maybe the size of a quarter. I'm wondering if and how this might affect my beer. I tasted the wort when it went into the fermentor. I didn't detect any sort of burnt flavors.

Also when I put the decocted mash back into my mash tun the temp only came up to about 145 degrees. I ended up scooping the mash back into my pot and heating it to 154 and just holding it there. Anyone see any problem with doing that?

 

[cheezydemon3]

I used to simulate a decoction (sorta) by skillet searing some of the wet mash.

It depends on the type of beer, but it always added the "complexity" often described by decoctors .

What was the grain bill?

 

[roger_tucker]

It's a Mailbock

5.5 gallon batch
90 minute boil
70% efficiency

1.076 OG
24.3 IBU's
8.3 SRM
7.4% ABV

10.5 lbs Pilsner (2 Row)
5.5 lbs Munich Malt
Bavarian Lager Yeast (Wyeast #2206) 2 Liter starter
.5 oz Magnum Hops - Boil 60 min

 

[IslandLizard]

For decoction mashing I now use 2 kettles, one for the main mash the other for the decoctions. Easier to keep or bring the main one back to where it should be.

As you noticed it is very difficult to gauge how much 30% of the thick portion of the mash is. That may have partly to do with not reaching the target rest temp once re-combined. Plus the main mash cooling down more than you want while you're too busy cooking and stirring.

A little "scorching" shouldn't hurt your beer. That's where Maillard reactions get their edge. Now burning a thick layer stuck to the bottom, like porridge tends to do when unattended, would not be good.

 

[cheezydemon3]

As long as it wasn't BLACK burnt, you should be fine. In fact, it might be fantastically impossible to re-create

I think you will be fine. Unfortunately, if it is burnt, it NEVER goes away.

 

[Roundhouse]

What type of decoction did you do? Single, double? What temperatures were you going to/from?

When I do a double decoction, I dough in with a water/grist ratio of about 1.75 qts/ 1 lb of grain. I generally adjust my strike water so it doughs in at a target of 131-133. After sitting for 15-20 minutes, I'll pull 1 qt of thick decoction per pound of grain used, draining most of the liquid off. I bring this to a boil in a separate kettle. After the boil time is over, I slowly add it back a scoop at a time or so until the next target rest temp is hit. It needs to be stirred well. There is always some decoction left over in the kettle. I let it sit in there while it slowly cools and the main mash rests. After the rest period, the remaining decoction portion left over in the kettle is usually cooled enough to be added back to the main mash. It is stirred in well and then the second decoction is pulled. This one is only taking the mash from about 144 to 158 so I only pull 1/2 qt per pound of grain which is half the amount of the first pull. Most of this will get added back to the main mash after boiling. My main mash is in a cooler so it doesn't lose much heat. The final rise to mashout is done by draining the liquid off of the mash and bringing it to a boil. It is then mixed back in. I haven't had any scorching issues but I don't keep the flame too intense. I do stir the entire time which is a bit tedious.

For a single decoction, I'll do a normal infusion mash. Let's just say at 150° for example. This will be doughed in at a ratio of 1.25 qts water/ 1 lb of grain or so which is noticeably thicker than the double. After 45 minutes into the rest I'll pull just slightly over a third of the mash and bring it to a boil. It will be added back to hit mashout temperature.

I'm not sure how you do it but that is my method and it has worked great for me. I've never had any issues hitting my temps and I've never scorched anything. What you described will probably be just fine so don't sweat it. If it tastes good, drink it!

 

[roger_tucker]

The scorched area was black, but it was not thick. The smaller spots scrubbed right off with almost no effort. The spot that was a few inches in diameter took a little bit more scrubbing but it wasn't like I had to take a putty knife to it.

 

[roger_tucker]

What type of decoction did you do? Single, double? What temperatures were you going to/from?

I did a single decoction. I mashed in for a protein rest shooting for 122 degrees for 25 minutes. I actually hit 125 degrees. I pulled 14 quarts of dry mash for the decoction, so slightly less than 1 quart per pound. I brought that to a boil for 5 minutes and then added the decoction back to the mash tun. I was shooting for a 154 degree sacchrification rest for 45 minutes. I only hit about 145 when I added the decoction back to the mash tun. So I scooped my mash into my pot and brought it up to 154 and just kept adjusting the heat to keep it there.

This will be doughed in at a ratio of 1.25 qts water/ 1 lb of grain or so which is noticeably thicker than the double.

The folks at the LHBS actually told me I probably want to go with a little thicker mash. So that if I didn't hit my temps when I added the decoction back to the tun I could add some boiling water. I regretfully chose to ignore that advice.

 

[Roundhouse]

It can be a learning curve. Try it again. You'll get it.

 

[IslandLizard]

5 minutes boil only? You're not going to get a lot of melanoidens from that. 20-40 minutes are more common, at least for double and triple decoctions. If you have a triple ply bottomed kettle scorching should be minimal, as long as you scrape and turn the bottom mash up. And yes, when re-combining small additions and good stirring is the right way. The schedule should tell you to raise from 122 => 147 over say 15 minutes.

The mash should be fairly loose so most of the enzymes remain behind in the liquid phase. 1.50-1.75 is common I think. And the steps in the decoction portion include usually heating periods to one or more rest temps, (e.g., 122 => 133 or 133 => 147) and hold each there for x minutes, so that thick mash can actually convert properly before being boiled.

 

[Roundhouse]

The point of a decoction is not only to get melanoidins. If that's all there were to it you could just add some melanoidin malt and be done with it.

 

[VladOfTrub]

As long as it doesn't smell like burnt toast it should be OK. Only, aging will tell if the mash picked up a flavor. There should be liquid laying on top of the mash before taking it to a boil. In the beginning I scorched decoctions. Live and learn.

A 5 minute boil really doesn't do too much except for getting the decoction hot enough to reach a rest temp in the main mash. At 10 minutes of boiling, hard starch that gets stuck in the tips of the husk will burst and enter into solution. The decoction method allows the brewer to take advantage of the excess starch in solution. That is a reason why wort produced from a decoction has higher starting gravity, than wort produced by the English method, pound for pound. Boiling a little longer than 10 minutes begins to break down protein gum. The action helps during fly sparging. It also helps in cleaning some goop up early in the process.

Melanoidin begins to form soon as Malliard reaction is noticed, by the darkening of the mash. Now here's the thing and I'll refer back to what Lizard mentioned. Lizard mentioned that the decoction is rested at various temps, converted and boiled. Here's a reason why. Melanoidin is formed when protein, sugar and amino acid hook up. Allowing beta, alpha or both to work on the starch in the decoction, creates sugars. The sugar will help in producing melanoidin when the decoction is boiled. If the brewer decides not to form melanoidin, he/she may still decide to allow the decoction to convert, using mash pH and temperature to determine the optimum range of an enzyme. Then, using that enzyme when in the optimum pH and temp band for conversion. Also, the decoction will darken during conversion.

If a high attenuating, highly fermentable beer is being brewed, a thinner mash works best. However, a thick mash preserves enzymes. Usually, it's better to dough in on the thick side. Throughout the process, hot water might need to be infused for hitting a rest temp, temp maintenance or thinning. By the end of the process over 2qt/lb might be infused.

Hitting 145F wasn't a bad thing. Actually, you lucked out. Consider it this way. It's a beta rest at a temp before starch gelatinization begins. Starch begins to jell at 149F. When you hit 154F, starch continued to gelatinize. When starch gelatinizes, enzymatic action slows down. Beta denatures quickly at 154F, leaving alpha enzyme on deck. Temperature at 145F gave beta a chance to work on starch and will help to balance the beer.

 

[cheezydemon3]

Hopefully all the burnt bits stuck to the bottom.

 

[roger_tucker]

Good information. I also watched the Kaiser videos on YouTube last night. I wish I'd have seen those before I started. There something about a German dude giving instruction on how to brew a German lager using traditional German mashing techniques that adds a certain weight of authority.

 

[wobdee]

Something else I heard Kai talk about was how some German brewers don't boil the decoction, just bring it up to near boil temp and hold it for an amount of time. That would help prevent scorching and lessen the darkening I would think.