Decoction using a Pot within a Pot? (boiling water)

[Bassman2003]

Hello,

I tried searching for this but there are too many overlapping terms.

I was wondering of anybody has put a pot inside a pot of boiling water to execute a decoction? I heard this on a Brewcaster episode many years ago. The thought is to remove scorching risk by putting a smaller stock pot with the grains inside a boil kettle which would have boiling water bubbling away. The only question is if the grains would actually make it to a boil themselves. Is there enough heat transferred to bring the grain to a boil? This would be for a 5 gallon batch so probably 3 pounds of grain and 2.5 gallons of water.

Just exploring at this point and the approach might have fatal flaws but thought it would be a decent discussion. Thanks.

 

[DBhomebrew]

You're talking a 'double boiler'. Used to heat chocolate, milk, etc. I'd think it'd be too gentle for a decoction. Likely to add a ton of time to the day.

 

[IslandLizard]

I too doubt a "Bain Marie" will get your mash to boiling temps. It's also fairly slow heating that way.

I do serial mashes and decoctions over direct heat, using a thick tri-ply bottom brew kettle on an induction burner, at reduced power, around 1500W +/-.
Just keep stirring and scraping the bottom while heating/boiling. I get a slight "sticky" area in the middle of the pot, where the burner projects, but no scorching or burning.

 

[Bassman2003]

Thanks for your input. I was hoping to find a way not only to minimize the scorching/effort but also to use a brew bag. My thought was to put the 3 pounds of grain in a separate bag inside my main mash bag from the start. I could then just lift it out and place it in the separate pot, boil it then place it back in the main mash. The liquid would be easy to scoop or pour. I guess I could employ a false bottom to keep the bag suspended?

I am trying to keep the process as low oxygen as possible ( I know,...) If it gets complicated I will not do it as I managed twenty years without doing a decoction, why spoil it now?

 

[HM-2]

You won't really achieve "decoction", becasue the impacts of direct heat are required to create the melanoidins.
You can basically avoid scorching with plenty of stirring and control of your burner / cooker.

 

[Bassman2003]

Thanks. I have seen some other approaches like only starting with 1/3 of your mash, doing a rest, then bringing that to a boil. Then add the rest of the grain and strike water to bring the whole thing back down to the 140's F to start a Hochkurz mash. All in one pot with recirc along the way. Effort in probably equals benefit out but there might be a balance to be found.

 

[Bassman2003]

Back to revisit this and wanted to get opinions on this approach...

1) Grind the grain
2) Separate into two BIABs, 66% into the main bag, 33% into a 2nd bag
3) Dough in with the 33% bag inside the 66% bag
4) Run the mash schedule. (maybe a full beta rest, remove for alpha, return for mash out)
5) Remove the 33% bag and place in my boil kettle on this SS rack (Rack)
6) Pump 2-3 gallons from my recirc into the kettle
7) Boil for 15-20 min with induction heat. No stirring needed due to the bag being suspended
8) Drain the boiling wort into a SS container and gently pour back into the main mash
9) Place the bag back into the main mash (either leaving grain in the bag or dumping under the liquid level with tongs)
10 Wind up at mash out temps and proceed.

This approach would allow me to do all kinds of mash schedules (like hefe with an 111F rest) and not add too much extra time to the brew day as the decoction will be in the time of a decent length alpha rest.

What do you think about the SS grate sitting 1" off of the bottom of the boil kettle? Enough to get the decoction benefits but without the scorching?

Thanks for your input!

 

[IslandLizard]

I think you missed an important facet of decoction mashing.

Decoctions are done with a portion (say, 1/3-1/2) of the thick part of the mash. It consists mostly of grist with some clinging wort, scooped out with a strainer.
The thinner mash proceeds in the mash tun (such as in a cooler or recirculating by itself), while you're heating and stirring the thick portion for 30-60 minutes up to boil temps, and keep it there for as long as you want.
The boiled decoction then gets added back to the main mash resting (progressing) on the side, raising the temp to the next rest. You can do that 2 or 3 times.

 

[Bassman2003]

Thanks for your reply. Not sure why things went so basic. Maybe I need more context as I am trying to do exactly what you describe Island.

I have an Anvil Foundry that I use for mashing with a Wilserbrewer bag & false bottom and also a SS Brewtech 10gal pot with induction burner for boiling. By dividing the grist into the 66% bag (main mash) and the 33% bag (decoction) I am just making the extraction and return to the main mash easier and more tidy. I still will boil the 33% thick mash (contents of the bag) and add some wort from my recirc since the bag will not bring very much liquid over. The mash will begin with 100% of the grist in the mash and the thin mash will proceed after I take the 33% bag out.

My question was about using the 1" false bottom for the decoction boiling. I know the traditional homebrew decoction is about super heating on the edge of scorching but I am not looking to do this. I have seen others' with varied approaches to this boil with favorable results.

 

[OleBrewing]

there was an old northern brewer's episode

brewing tv was a great series with pretty good information and i believe the this guy created a lot of the recipes for northern brewer.

the chop n brew was also an entertaining series.

both are worth watching.

 

[mashdar]

IMO you need to stir a decoction with grain exposed to the heat, or you're missing the mark.

If you're not trying to produce the flavor from decoction, is this just a heat issue? What is the goal?

And definitely don't put multiple gallons of wort in it; you want it pretty thick. Extra liquid means you're hitting your amylase much harder.

 

[Bassman2003]

I am aiming for as much of the flavor benefits with as little extra effort as possible. I would like a process that might be easy enough for me to consider a decoction for any beer I make. If that involves losing some percentage of the ultimate flavor contribution, I can live with that for the repeatability.

I am not sure of commercial decoction techniques, but I would guess they are not worried each batch about if the grain scorches or not. I was under the impression that boiling the thick mash explodes the starches. To me, that is just boiling, not super heating. Boiling the grain would expose it to plenty of heat. Just not verge of scorching heat right? I am aware that more Maillard reactions happen the higher you go with temperatures above boiling. Yes that is a component but some who do pseudo decoctions seem to see benefits as well. Just trying to explore some territory.

 

[Red over White]

Thanks. I have seen some other approaches like only starting with 1/3 of your mash, doing a rest, then bringing that to a boil. Then add the rest of the grain and strike water to bring the whole thing back down to the 140's F to start a Hochkurz mash. All in one pot with recirc along the way. Effort in probably equals benefit out but there might be a balance to be found.

This is very similar to my decoct first, mash second approach. Everything is done in the mashtun with a loose mash. I do use an extra false bottom on top of the mash to keep the grain submerged during heating. I heat to 205 for 10 minutes while continuously recirculating before adding chilled strike water for the rest of the hochkurz mash. There are flavor benefits, improved foam stability and my decocted beers drop bright faster than any others. The single vessel approach has worked well for me, adds about 60 minutes and isn't messy at all.

 

[jerrylotto]

Decoction is supposed to support Maillard reactions, and I find the beginning of a color change to be the best indication that things are proceeding normally. Without direct heat I'm not sure you're going to see that. The flavor component that you're interested in comes from those reactions.

 

[Bassman2003]

Thanks Red over White. Encouraging to know you are seeing flavor benefits with a loose mash 'almost boil'. I think the crux of the concern in this thread is the difference of boiling the grain with direct contact with the pot vs boiling the grain with indirect contact. The former creating more flavor and benefits vs the latter creating less or none.

If I use the 1" grate, I will need at least the minimal amount of wort to get up to the grain in the bag. I see some side benefits of faster heating times without worrying about scorching, no stirring as well as simple out and back in to the main mash.

Red, I saw your process outlined in another thread. I like your approach but I wanted to be able to insert the decoction in any mash program like a hefe. For low oxygen, a full, slow dough in is an integral part of the process. So taking your experience I came up with a somewhat similar approach but with a different application. Being able to add the decoction say during beta or alpha allows me to brew a hefe and still do a 111F rest etc...

Opinions?

 

[Bassman2003]

Thanks Jerrylotto. So you think indirect will be effort without much flavor benefit.

 

[Red over White]

Thanks Red over White. Encouraging to know you are seeing flavor benefits with a loose mash 'almost boil'. I think the crux of the concern in this thread is the difference of boiling the grain with direct contact with the pot vs boiling the grain with indirect contact. The former creating more flavor and benefits vs the latter creating less or none.

If I use the 1" grate, I will need at least the minimal amount of wort to get up to the grain in the bag. I see some side benefits of faster heating times without worrying about scorching, no stirring as well as simple out and back in to the main mash.

Red, I saw your process outlined in another thread. I like your approach but I wanted to be able to insert the decoction in any mash program like a hefe. For low oxygen, a full, slow dough in is an integral part of the process. So taking your experience I came up with a somewhat similar approach but with a different application. Being able to add the decoction say during beta or alpha allows me to brew a hefe and still do a 111F rest etc...

Opinions?

If it was feasible with your equipment, doughing in both mashes separately at 111°F and conducting the decoction mash and adding it back into the main mash to get to the alpha rest would mean only moving it once. It would also give your enzymes a little extra time before mashout to convert any newly liberated starch from the decoction. Running 2 mashes side by side for a little while would be busy, but doable for an experienced brewer. I have found that doughing in at 113 and immediately ramping to 158 produces a wort with high attenuation (likely from more time for limit dextrinase to also work for a time below beta temps). Keep us posted on your method and outcome!

 

[Bassman2003]

Hello,

An update on this. I have the 13" grate and it fits in my 10.7 gal SS Brewtech really well. I made a few modifications for my purposes. I cut a larger square for my rotating spigot as well as cutting down the legs to lower the grate a bit. I figured I wanted to be as close as possible to generate the most heat. I will also boil with the lid on to increate the temps.

My goal is to have decoction be an easy choice which still getting a large amount of the benefits. As well as keeping it as low oxygen as possible. I plan on doughing in, raising the entire mash to 144F, resting for 20 min, pulling the bag with 1/3 of the grain and placing it in the boil pot and adding a little wort just to get the level up. Raise this up to 160F and resting for 15 min. then boiling for 15 min. I will then drain the liquid from underneath and place it back in the main mash, then lift the bag over and place it in the main mash. Then proceed to an alpha rest and mashout as normal. It will take me a few brews to see if it makes a difference, which it probably will but even if it does not, it will be fairly easy to execute. Thanks for the input!

Here are some photos:

 

[Bassman2003]

I wanted to update this thread because I have done two decoction brews with my bag within a bag approach. I have named it the d-bag (double bag) decoction. This was easy to execute and the grain did darken quite a bit.

Here is an image from the brew day video I made for the helles beer

You can see the grain in the upper section when it was first transferred compared to the grain on the bottom after the boiling. The lower image is quite darker. We will see if that translates to any flavor.

The whole brew day video can be found on my YouTube channel or in this thread - My Helles + Decoction Full Brew Day Video is Up

 

[mashdar]

Is there a way to estimate srm effect of decocting? Do any of the recipe calculators do that?

 

[jerrylotto]

Is there a way to estimate srm effect of decocting? Do any of the recipe calculators do that?

Visually is the only way I know of. Temperature, time, quantity and worth content of decoction pull, and the number of decoctions are all variables that can impact the SRM impact.

 

[1Pivoman]

I've been decoction mashing for 20+ years, and have recently moved to a single decoction schedule that is more intensive and gives the flavor/color contribution of a full double decoction while saving a significant amount of time. I typically do this method when I brew my lagers, which I use slightly undermodified malts (such as Sekado, Riverbend Czech Pilsner malt, and floor-malted Weyermann Bohemian Pilsner and Dark Malt) and also for all of my Hefe-Weizens.
I'll mash in at 52C (lower for my Weizens, around 44C or 113F), in my mash tun. I'll then pull 2/3 of the thickest part of the mash, not the typical 1/3, which is a hefty amount after 10-15 min rest, into my decoction pot that is a 5 gallon pot with tri-clad bottom for even heat distribution to help avoid scorching. I already will have 2/3-3/4 of a gallon of pre-heated water in the decoction pot because of the length of time I'm going to boil it to further avoid scorching.
This is where the twist comes in, I'll heat the decoction to either 65C or 72C, while at the same time raising the rest mash to 62-63C. I recently bought a cheap $11 water heater wand from Amazon that is about 11" long that you simply plug in and stir the rest mash gently with it to heat it to 62-63C. It's work, both hands are stirring mashes in two different kettles!! I'll also recirculate the rest mash so the wort under the false bottom isn't stuck at a lower temperature.
The decoction is allowed to convert for 15-20 min, then I boil it for a minimum of 10 min. Only a portion of the decoction is mixed with the rest mash, enough to boost it to 70-72C for the alpha amylase rest. The remaining decoction is boiled further, for another 20-30 min. I'll turn the heat down a bit but keep it boiling. One of the "gears" you can manipulate while decoction mashing is how vigorous you boil the decoction, as well as thickness and time it's boiled. Thicker decoctions boiled longer will impart more maillard reactions and color/flavor contributions to the finished beer.
The remaining decoction is then mixed into the rest mash to boost it to mash-out temp. I like the idea of not allowing the rest mash to just park at protein rest temps any longer than I have to, and heating the rest mash after a 10-15 rest definitely accomplishes that. You could skip this rest and just do a "hochkurz" mash, which I've done with more modified German malts.

 

[Bassman2003]

Thanks for sharing! More data is great.