Decoction question

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h22lude

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AHA posted an Oktoberfest recipe that I'd like to try. I have never done a decoction but want to try with this one. Here is the mash schedule...

Mash in at 129° F (54° C) for 5 minutes.
Ramp to 150° F (63° C) and hold for 30 minutes.
Run a single decoction mash: remove 40% of the grain and heat it separately to 158–162° F (70–72° C) for 15 minutes, then bring to a boil for 5–10 minutes and return to the mash.
Mash out at 167° F (75° C) for 5–10 minutes.


I understand I take out about 40% of the grains with enough wort to keep the grains moving around when stirring. What am I doing with the other 60% of grains and remaining wort? Do I start bring that up to 167° or leave at 150° until I put the 40% back in then bring up to 167°?

Is there an easy way to estimate how much grains you are taking out or eyeballing it is fine?
 

bajaedition

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leave what is in the mash tun alone, the grains you are boiling will raise the temp when youre add them to the mash
 

BigEd

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AHA posted an Oktoberfest recipe that I'd like to try. I have never done a decoction but want to try with this one. Here is the mash schedule...

Mash in at 129° F (54° C) for 5 minutes.
Ramp to 150° F (63° C) and hold for 30 minutes.
Run a single decoction mash: remove 40% of the grain and heat it separately to 158–162° F (70–72° C) for 15 minutes, then bring to a boil for 5–10 minutes and return to the mash.
Mash out at 167° F (75° C) for 5–10 minutes.


I understand I take out about 40% of the grains with enough wort to keep the grains moving around when stirring. What am I doing with the other 60% of grains and remaining wort? Do I start bring that up to 167° or leave at 150° until I put the 40% back in then bring up to 167°?

Is there an easy way to estimate how much grains you are taking out or eyeballing it is fine?
You should do the decoction pull based on weight, not volume. I like to use the 40% figure rather than the by-the-books 1/3 because it's very easy and very common to come in under temperature first time with the 1/3. So what you want is ~40% of the total weight of the mash (water and grains) taken out (the decoction pull) in the form of drained grains. So, for example, if you have 10 lbs of grain and 10 quarts of water to mash in that's 30 lbs total so 40% will be 12 lbs for the decoction pull.

I use a SS mesh kitchen strainer to remove the grist from the mash, letting it drain for a few seconds before dumping into the decoction vessel. To be safe as a little extra temperature cheat and to help prevent scorching you can start with a little water in the decoction vessel as a buffer.

Leave as much wort behind in the mash tun when doing the pull because most of the enzymes are in that solution. One way to figure the weight of the pull is to weigh one scoop or some known volume and then eyeball from their. One of my scoops of grist weight 1.5 lbs so if I need to pull 18 lbs that's 12 scoops.

Once you have grist in the decoction vessel, keep it moving to prevent scorching and also to keep the temperature uniform. The decoction will thin out a bit as it heats but it still should stay fairly thick, sort of a soft, pudding consistency. You can, and probably should, boil it for longer than 10 minutes as the longer it boils the more complex flavor and aroma compounds will be created.

The remaining mash does just that, remains. Once the boiled decoction pull is added back and thoroughly mixed back in the result should be a temperature increase of ~20F. If you come up way too short or severely overshoot, having boiling water and cool water on standby is a quick way to adjust. By the way you can pull the first decoction as soon as you have finished mashing in.
 
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h22lude

h22lude

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You should do the decoction pull based on weight, not volume. I like to use the 40% figure rather than the by-the-books 1/3 because it's very easy and very common to come in under temperature first time with the 1/3. So what you want is ~40% of the total weight of the mash (water and grains) taken out (the decoction pull) in the form of drained grains. So, for example, if you have 10 lbs of grain and 10 quarts of water to mash in that's 30 lbs total so 40% will be 12 lbs for the decoction pull.

I use a SS mesh kitchen strainer to remove the grist from the mash, letting it drain for a few seconds before dumping into the decoction vessel. To be safe as a little extra temperature cheat and to help prevent scorching you can start with a little water in the decoction vessel as a buffer.

Leave as much wort behind in the mash tun when doing the pull because most of the enzymes are in that solution. One way to figure the weight of the pull is to weigh one scoop or some known volume and then eyeball from their. One of my scoops of grist weight 1.5 lbs so if I need to pull 18 lbs that's 12 scoops.

Once you have grist in the decoction vessel, keep it moving to prevent scorching and also to keep the temperature uniform. The decoction will thin out a bit as it heats but it still should stay fairly thick, sort of a soft, pudding consistency. You can, and probably should, boil it for longer than 10 minutes as the longer it boils the more complex flavor and aroma compounds will be created.

The remaining mash does just that, remains. Once the boiled decoction pull is added back and thoroughly mixed back in the result should be a temperature increase of ~20F. If you come up way too short or severely overshoot, having boiling water and cool water on standby is a quick way to adjust. By the way you can pull the first decoction as soon as you have finished mashing in.
Great explanation, thanks! I didn't realize most of what you pull for the decoction is grain. I was always under the impression that it was a mix of grains and wort to be a thicker soup consistency. The way I read your post, it should be more like thick oatmeal.
 

bajaedition

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You want me to watch them?

or the OP?

I simply posted a quick video, not a long involved video

If that offends you sorry
 

VladOfTrub

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Try this. Crush 40% of the grain by weight into the decoction kettle and the remainder crush into the mash tun. Dough in the decoction mash and main mash with 1 qt/lb RO water @ 60F. Allow the mash to rest for a few minutes to allow the inherent pH of the grain to stabilize the brewing water pH. Add sauer malz if necessary to reduce pH in the decoction and main mash to 5.5, 5.3. The pH of the mash MUST be established before enzymatic action begins. That's why the mash is doughed in cold and pH established, the enzymes are doing very little at 60F. Now, here is where the quality of malt comes into play. If you are using high modified, modern malt like many home brewers use, the enzymatic richness of the malt is poor and usually, hi-modification is associated with a high percentage of protein which means that the malt contains less sugar. A very fine malt for Oktoberfest is Weyermans dark floor malt. It is brewers grade malt. It has the enzymatic richness and low percentage of protein which is needed to produce Ale, Lager and Pils. The recipe from the AHA is probably based on using less expensive, high modified, modern malt. With brewers grade malt, more temperatures are used during the brewing process when Oktoberfest is produced. The malt is more complex and requires a more involved brewing method to take advantage of the complexities.
Procedure begins as mentioned above:

Instruction when Weyerman dark floor malt is used:

So, now we have the split grain bill soaking in cold water at 60F or so and resting at an acceptable pH. Next step.

Begin to heat the decoction mash raising the temperature to 122-125F and rest the mash for 15 minutes or so, not too long. Proteinase rest. Next step.

Crank up the heat and raise the decoction mash to 155F and rest the mash for 20 to 30 minutes. Test with iodine for presence of starch. If starch is present, do not worry. This is the only rest used to produce sweet, non fermenting sugar produced by Alpha II. It is enough. Next step.

Begin to boil the decoction. As the decoction boils skim off hot break as it forms. Here's the thing, the length of boiling time recommended in the recipe will do little for an Oktoberfest style of beer. Boil the decoction for one hour ensuring that the mash does not scorch. A large amount of amylo-pectin will be released, protein gum will reduce and if all the ducks line up melanoidin will form during the boil. Pay attention to detail and remember what is occurring in the decoction. Write stuff down if necessary. Next step.

Add the boiling decoction into the 60F main mash. The temperature to reach in the main mash is 130F. Stay close to 130F but, if the temp is a degree or so higher, not to worry. If it is lower than 130F add boiling water to reach 130F. At this time proteinase will release glucose from Beta Glucan, mash viscosity reduces. Next step.

When the temperature of the main mash stabilizes at 130F remove the 2nd decoction. Hold the temperature of the main mash very close to 130F throughout the time when the 2nd decoction is being worked on. Now, we are on Mother Natures time clock, enzymes are kicked in gear. For horseshoes and hand grenades close, assume that one gallon of saturated mash weighs eight pounds and start with 1/3 of the total weight/volume of malt and water used in the entire mix theory and develop a base line. Next step.

When the proper volume/weight of mash is in the decoction kettle increase the heat of the decoction mash from 130F to 145F and rest the decoction for 15 minutes after the mash reaches 145F. First maltose rest. Next step.

Crank up the heat and begin to boil the decoction and boil it for 20 minutes, skimming off hot break as it forms. Next step.

Return the boiling decoction into the main mash which is resting at 130F or so, and raise the temperature to 153F. When the main mash temperature is stable at 153F check pH and reduce it to 5.2 if necessary. Beta will be active for a short time and Alpha will do the rest. When the mash was boiled amylo-pectin burst and entered into solution. The starch is heat resistant and temperatures above 169F are required to cause the starch to burst. The starch is a complex starch and it is responsible for body. Alpha liquefies the starch releasing A and B limit dextrin which are tasteless, non fermenting types of sugar. The mash being at 153F is at a temperature slightly above the temperature at which dextrinization begins, so we good. The mash may jell up when the hot decoctions hit the cold mash, it has to do with pectin. It will go away. Rest the mash at 153F for 20 to 30 minutes. Next step.

Infuse boiling water into the main mash resting at 153F and raise the temperature to 158 to 162F, somewhere around there. Then, remove most of the mash water from the main mash and boil it for ten minutes or so in the decoction kettle. Next step.

Add the boiling mash liquid into the main mash and raise the main mash temperature to 168F. Use boiling water to reach 168F, it will be needed. The additional water will thin down the mash making it easier to work with during sparge. Let the mash settle for 10 or so minutes. Next step.

Stir the mash a couple of times, close the lid and let the mash settle. During settling a layer of protein mud will form and cover the grain bed and the liquid above the mud should be clear enough to see it. During vorlauf try not to stir up the mud when adding the liquid into the mash. The same goes during sparging. Keep enough water above the grain bed to not disturb the mud during vorlauf and sparge. Check pH for starting a baseline. The pH should be around 5.2 to 5 which is good. If it isn't, something went completely haywire. Next step.

Begin sparge and run extract into the wort boiler until gravity of the run off falls to 1020. Check pH. Run off can continue to 1015 but 1020 makes a high quality Oktoberfest. As soon as the bottom of the boiler is covered with wort, fire it up. Boil the wort until hot break ceases to form, before adding bittering hops. As hot break forms skim it off and skim the second break after hops are added. Boil for the usual hour.

The beer will require second fermentation and a long aging phase. The beer will not require priming or artificial carbonation.
 

BigEd

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Try this. Crush 40% of the grain by weight into the decoction kettle and the remainder crush into the mash tun. Dough in the decoction mash and main mash with 1 qt/lb RO water @ 60F. Allow the mash to rest for a few minutes to allow the inherent pH of the grain to stabilize the brewing water pH. Add sauer malz if necessary to reduce pH in the decoction and main mash to 5.5, 5.3.

Very clever! I like the sound of that two vessel start. Will have to give it try. :mug:
 

VladOfTrub

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Very clever! I like the sound of that two vessel start. Will have to give it try.

I know, heyna!!!
I thought everyone knew that is the way that it is done!!!
Everyone, except for the guys producing vids and writing about the decoction method, which home brewers can somehow discern that the guys know what they are talking about. Then, they get all gooey when they watch them or read their stuff and go on to suggest to others who have little knowledge about producing beer that the vids and info are excellent for instructing.
 
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h22lude

h22lude

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Thank you for the great explanation Vlad. I need to go through your post again and take some good notes. I will be trying this on a brew soon.
 

HBHcustom

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I would like to try to simplify my decoction technique to save time and for safety reasons. Would it be possible to simply mash two thirds of my grains in the regular fashion while at the same time, in a separate vessel mash the other third, then after initial rest bring the smaller mash to a boil and then add it to the larger mash.
 
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