45 min mash

[Bassman2003]

That's probably the same paper that I attached up-thread. It found that at 140°F (60°C) that limit dextrinase maintained 100% of its activity after 60 minutes. But, unless you grind exceedingly fine, you will not get much gelatinization at 140°F. Raising the temp of the rest to 149°F will give you faster gelatinization, while still maintaining high limit dextrinase activity after 60 minutes.

Yes, the temp range for a beta rest and a limit dextrinase rest are pretty much the same.

If your beers are too thin for your tastes, then you are probably hydrolyzing too many of the limit dextrins, and you don't have enough dextrins in the final wort to give you the body you are looking for. Also, if you are doing a protein rest, that might contribute to thinness. I'd recommend cutting back on the time spent at lower temp rests.

Brew on

Yes and thanks. Gel temps are kicker! I usually do what is referred to as a 'coast down mash' where one doughs in at say 150F and lets the mash drift down in temperature. This gets some gelatinization going while drifting back down into beta territory before it gets denatured.

I see now that the dough-in temperature is very important for the strategy. The higher the dough-in, the faster beta/LD will work. The lower the dough-in the slower. There are some times when I did not reach 150F and started in the 140s which leads to longer times spent in beta to hit my gravity target. Sometimes 70+ minutes to get to 90% of pre-boil gravity.

I might lower the target to 80 or 85% and also raise my initial dough-in temp to shorten the time spent in the 140's as 70min is too long.

To the OP - sorry for the pointy headed takeover but hopefully we all learn things!

 

[AlexKay]

Just a note on the iodine test for starch: it is selective for amylose, as opposed to amylopectin.

Amylopectin makes up the majority of starch in barley, and it converts more slowly.

So “complete conversion” means ~30% for sure, while hoping for the rest.

 

[doug293cz]

Just a note on the iodine test for starch: it is selective for amylose, as opposed to amylopectin.

Amylopectin makes up the majority of starch in barley, and it converts more slowly.

So “complete conversion” means ~30% for sure, while hoping for the rest.

This is interesting, and something I have not read about yet. Do you have some references you could share? I'd like to see information on ratios of amylose to amylopectin, relative gelatinization rates of each, and rates of hydrolysis of each.

Brew on

 

[AlexKay]

This is interesting, and something I have not read about yet. Do you have some references you could share? I'd like to see information on ratios of amylose to amylopectin, relative gelatinization rates of each, and rates of hydrolysis of each.

Brew on

I don’t have anything beyond “some guys told me once.” (To be fair, though, the guys in question had PhDs in food science or something.)

Some Googling comes up with
https://beerandbrewing.com/dictionary/D1YfYtjBRf/
(and references therein) for the amylose:amylopectin ratio.

Gelatinization looks complicated, with starch granule structure dependent on packing of amylose and amylopectin together, along with the relative chain lengths of each. This article seems on point, though in the weeds:
Link

 

[doug293cz]

I don’t have anything beyond “some guys told me once.” (To be fair, though, the guys in question had PhDs in food science or something.)

Some Googling comes up with
https://beerandbrewing.com/dictionary/D1YfYtjBRf/
(and references therein) for the amylose:amylopectin ratio.

Gelatinization looks complicated, with starch granule structure dependent on packing of amylose and amylopectin together, along with the relative chain lengths of each. This article seems on point, though in the weeds:
Link

Thanks.

Brew on

 

[doug293cz]

Yes and thanks. Gel temps are kicker! I usually do what is referred to as a 'coast down mash' where one doughs in at say 150F and lets the mash drift down in temperature. This gets some gelatinization going while drifting back down into beta territory before it gets denatured.

I see now that the dough-in temperature is very important for the strategy. The higher the dough-in, the faster beta/LD will work. The lower the dough-in the slower. There are some times when I did not reach 150F and started in the 140s which leads to longer times spent in beta to hit my gravity target. Sometimes 70+ minutes to get to 90% of pre-boil gravity.

I might lower the target to 80 or 85% and also raise my initial dough-in temp to shorten the time spent in the 140's as 70min is too long.

To the OP - sorry for the pointy headed takeover but hopefully we all learn things!

I wouldn't recommend raising the dough-in temp, unless you are shooting for a less fermentable wort. The higher the initial "stable" mash temp, the faster the limit dextrinase will denature, the less total LD action you will get in your mash, and the lower the fermentability.

By initial stable mash temp, I mean the temp achieved when the grain and strike water reach a temperature equilibrium. It's not really stable, as it will drift lower with time, unless additional heat is added to the mash.

Brew on

 

[Broothru]

I wouldn't recommend raising the dough-in temp, unless you are shooting for a less fermentable wort. The higher the initial "stable" mash temp, the faster the limit dextrinase will denature, the less total LD action you will get in your mash, and the lower the fermentability.

By initial stable mash temp, I mean the temp achieved when the grain and strike water reach a temperature equilibrium. It's not really stable, as it will drift lower with time, unless additional heat is added to the mash.

Brew on

This thread has caused me to fall down an incredible rabbit hole from which I’m attempting to find a way out. There may be some light at the end of this tunnel.

After reading, then re-reading some of these posts, and following them to the logical conclusions reached through Google searches of abstracts of research papers, authoritative articles, and anecdotal experiences, several things appear to repeatedly hold true:

First, gelatinization must occur. Temperature in the “protein rest” range 113F-131F provides an optimal range for that to occur, even though it is slightly below the level for maximum efficiency of about 147F-149F.

Gelatination rate increases with temperature up to about 160F, but b-amylase is denaturing by then. 147-149F is where b-amylase is most active, but is above the temperature that limit dextrinase is optimal in debranching 1,6 glycosidic bonds for beta to convert.

So, what temperature(s) are best for this part of mash? Maybe ~135F dough-in which would allow for ‘reasonable’ gelatinization and allow limit dextrinase some space to debranch before it exceeds its maximal temperature range. B-amylase is already actively converting sugars by now.

Stepping to 147-149F after :15-:20 minutes rest at ~135F or so will allow beta to finish up the bulk of its work more quickly. A brief rest here 20 mins @ 148F?) and the on to a-amylase optimum (~158F) rest, and then 178F to mash out and finish denaturing the enzymes. Does this sound about right/logical?

After stumbling upon a Scott Janisch blog post a few years back that seemed to dispel some long-held beliefs about mouthfeel and head retention (dextrins), this all started to make for an “Aha” moment. Right now I’m trapped between “aha” and “aw “s**t”, not knowing if it’s a revelation or just ridiculous.

Any thoughts/comments before I pass through the matrix and stagger into testing theory against fact?

 

[mac_1103]

This thread has caused me to fall down an incredible rabbit hole from which I’m attempting to find a way out. There may be some light at the end of this tunnel...
Any thoughts/comments before I pass through the matrix and stagger into testing theory against fact?

Holy mixed metaphors Batman!

 

[mac_1103]

I think we should start a go-fund-me to buy Doug some pure beta amylase.

 

[corncob]

https://scottjanish.com/dextrins-and-mouthfeel/

This one?

 

[Broothru]

https://scottjanish.com/dextrins-and-mouthfeel/

This one?

Yep. That’s the one.

 

[Bassman2003]

I wouldn't recommend raising the dough-in temp, unless you are shooting for a less fermentable wort. The higher the initial "stable" mash temp, the faster the limit dextrinase will denature, the less total LD action you will get in your mash, and the lower the fermentability.

By initial stable mash temp, I mean the temp achieved when the grain and strike water reach a temperature equilibrium. It's not really stable, as it will drift lower with time, unless additional heat is added to the mash.

Brew on

What is your perfect mash profile with regards to limit dextrinase?

 

[Bassman2003]

This thread has caused me to fall down an incredible rabbit hole from which I’m attempting to find a way out. There may be some light at the end of this tunnel.

After reading, then re-reading some of these posts, and following them to the logical conclusions reached through Google searches of abstracts of research papers, authoritative articles, and anecdotal experiences, several things appear to repeatedly hold true:

First, gelatinization must occur. Temperature in the “protein rest” range 113F-131F provides an optimal range for that to occur, even though it is slightly below the level for maximum efficiency of about 147F-149F.

Gelatination rate increases with temperature up to about 160F, but b-amylase is denaturing by then. 147-149F is where b-amylase is most active, but is above the temperature that limit dextrinase is optimal in debranching 1,6 glycosidic bonds for beta to convert.

So, what temperature(s) are best for this part of mash? Maybe ~135F dough-in which would allow for ‘reasonable’ gelatinization and allow limit dextrinase some space to debranch before it exceeds its maximal temperature range. B-amylase is already actively converting sugars by now.

Stepping to 147-149F after :15-:20 minutes rest at ~135F or so will allow beta to finish up the bulk of its work more quickly. A brief rest here 20 mins @ 148F?) and the on to a-amylase optimum (~158F) rest, and then 178F to mash out and finish denaturing the enzymes. Does this sound about right/logical?

After stumbling upon a Scott Janisch blog post a few years back that seemed to dispel some long-held beliefs about mouthfeel and head retention (dextrins), this all started to make for an “Aha” moment. Right now I’m trapped between “aha” and “aw “s**t”, not knowing if it’s a revelation or just ridiculous.

Any thoughts/comments before I pass through the matrix and stagger into testing theory against fact?

It is my understanding that gel temps for today's malt tend to be around 150F. If gelatinization was strong at 135F mashing would be a lot easier! The rub is that gel temps tend to be higher than the beta rest range. Which is why some do the "coast down" mash which is designed to hit gel temps first then drift down to beta temps with the help of gelatinization being further along than if you just started at beta.

 

[IDMaynard]

I’ve been doing BIAB for almost a year now. I’ve played around with 30-90 minute mash times. I have not found any significant gain in mashing beyond 45 minutes. I am now planning 45 minutes for all my brews except when I am multi- tasking and end up going longer.
Any thoughts on this?

Sounds a lot like the Short & Shoddy brew series by Brulosophy, Martin Keen has a lot of pod casts on this very subject.
https://brulosophy.com/projects/short-shoddy/

 

[doug293cz]

What is your perfect mash profile with regards to limit dextrinase?

If I wanted absolutely the highest fermentability, without adding additional enzymes, I would mash at 147°F (64°C) until the SG was stable for at least 15 minutes (no increase in SG over a 15 minute interval.) Then if I also wanted to ensure maximum conversion, I would slowly heat to 170°F (76.5°C) to gelatinize and convert any difficult to gelatinize starch. Mash pH (room temp sample) should be 5.3 - 5.4.

I BIAB with a crush at 0.022" mill gap, and usually mash single infusion with a starting mash temp of 152°F - 154°F. Temp drops to 147°F - 149°F after an hour. I usually get pretty good attenuation, but I don't target specific FGs. Depending on recipe, I my FGs typically range from 1.006 - 1.016.

Brew on

 

[doug293cz]

It is my understanding that gel temps for today's malt tend to be around 150F. If gelatinization was strong at 135F mashing would be a lot easier! The rub is that gel temps tend to be higher than the beta rest range. Which is why some do the "coast down" mash which is designed to hit gel temps first then drift down to beta temps with the help of gelatinization being further along than if you just started at beta.

The issue with a "coast down" mash, is if the initial temperature is in the mid 150's or higher, you will be significantly denaturing your beta amylase, and limit dextrinase, before you cool down to temps where denaturing occurs at a slow enough rate for the enzymes to last all or most of the mash duration. You can definitely make good beer this way, but it is not the best way if very high, or maximum, attenuation is your goal. Once you denature enzymes, you can't get them back by cooling things down.

Brew on

 

[Broothru]

It is my understanding that gel temps for today's malt tend to be around 150F. If gelatinization was strong at 135F mashing would be a lot easier! The rub is that gel temps tend to be higher than the beta rest range. Which is why some do the "coast down" mash which is designed to hit gel temps first then drift down to beta temps with the help of gelatinization being further along than if you just started at beta.

I saw your description of “coast down” in an earlier post, and it made a lot of sense. I did some brainstorming about doughing-in at 135F to energize limit dextrinase without maximizing b-amylase for about 5-10 minutes, then pulling a detoction volume and bringing it to about 95~98C to denature all the enzymes and also produce melanoidins. So basically running parallel but different mash profiles concurrently. After ‘boiling’ the detoction, return it to the regular mash at the end of the b-amylase rest. Complete the mash with a-rest ~158F and mash out 178F.

This should ensure thorough gelatinization and hydrolysis, along with adequate sugars, enzymes and limit dextrins to achieve the conversion goals of the mash and the desired body and mouthfeel.

 

[Bassman2003]

If I wanted absolutely the highest fermentability, without adding additional enzymes, I would mash at 147°F (64°C) until the SG was stable for at least 15 minutes (no increase in SG over a 15 minute interval.) Then if I also wanted to ensure maximum conversion, I would slowly heat to 170°F (76.5°C) to gelatinize and convert any difficult to gelatinize starch. Mash pH (room temp sample) should be 5.3 - 5.4.

I BIAB with a crush at 0.022" mill gap, and usually mash single infusion with a starting mash temp of 152°F - 154°F. Temp drops to 147°F - 149°F after an hour. I usually get pretty good attenuation, but I don't target specific FGs. Depending on recipe, I my FGs typically range from 1.006 - 1.016.

Brew on

Thanks for your reply.

 

[Bassman2003]

The issue with a "coast down" mash, is if the initial temperature is in the mid 150's or higher, you will be significantly denaturing your beta amylase, and limit dextrinase, before you cool down to temps where denaturing occurs at a slow enough rate for the enzymes to last all or most of the mash duration. You can definitely make good beer this way, but it is not the best way if very high, or maximum, attenuation is your goal. Once you denature enzymes, you can't get them back by cooling things down.

Brew on

I do not think one would dough-in any higher than say 151F for a coast down mash. You do not want to get too far away from beta temps as enzymes will denature and it will take too long to actually drift down in temperature. The drift down mash is a good fit for all in one setups. My Anvil Foundry does better if the recirc is not started until 10 minutes into the mash. This allows one to start at 150F and not have to turn the heat on for quite some time and do the recirc upon taste.

 

[Broothru]

I do not think one would dough-in any higher than say 151F for a coast down mash. You do not want to get too far away from beta temps as enzymes will denature and it will take too long to actually drift down in temperature. The drift down mash is a good fit for all in one setups. My Anvil Foundry does better if the recirc is not started until 10 minutes into the mash. This allows one to start at 150F and not have to turn the heat on for quite some time and do the recirc upon taste.

Good points on the dough-in/recirc to bring temps down from 150Ish to limit dextrinase temps. I’ll try that on my Braumeister AIO.

 

[tracer bullet]

I do not think one would dough-in any higher than say 151F for a coast down mash

I'm curious what this does for the final product? New one for me and doing a google search on it brought me right back to this thread!

 

[Bassman2003]

What it does is shorten the time you spend in the 140's F to get access to the beta amylase activity which is beneficial for better attenuation. By starting at 150F you gelatinize the grain as opposed to starting at say 144F where you are not gelatinizing as much. So you would need to stay at 144F a lot longer if you start at a lower temp.

"Coast down" is a term from another forum that I belong to that is shunned around here. It has a lot of smart brewers and I adopt a lot of their practices.

 

[Broothru]

What it does is shorten the time you spend in the 140's F to get access to the beta amylase activity which is beneficial for better attenuation. By starting at 150F you gelatinize the grain as opposed to starting at say 144F where you are not gelatinizing as much. So you would need to stay at 144F a lot longer if you start at a lower temp.

"Coast down" is a term from another forum that I belong to that is shunned around here. It has a lot of smart brewers and I adopt a lot of their practices.

In aviation we used to talk about “drift-down.” I may start using that term-of-art if this works in my next mash.

Have you tried an infusion of cooled mash water into the recirculating mash to accelerate the ‘driftdown’ into optimal limit dextrinase range? I’m thinking dough-in at 150F, rest for :10 minutes, infuse to bring temperature down to 140F, pull a detoction volume for boil. Then restart the mash for b-amylase while boiling the detocted volume. Add the detoction back to the mash when a-amylase temperature is reached (158F) to continue through the rest of the mash (alpha + mash out).

It sounds complicated, but in practice I don’t think it would be any harder than a normal detoction mash. The main benefit would be capturing the zenith points for the three enzymes you’re looking to maximize (b-amylase, a-amylase, and limit dextrinase). I can see how you could achieve high conversion and efficiency without sacrificing body, and maybe pick up some melanoidins in the process. Might take my Continental lagers to the next level.

 

[Bassman2003]

That would be a good approach. In reality, you do not want to spend very long at 150F as it denatures beta. I am restrained by my low oxygen approach so I would need the cold water to be prepped before adding it. So it would be easier for non-low oxygen brewers. But yes, that would wring the best out of the strategy. I seem to remember gelatinization being a somewhat quick process.

Here are some links for the nerds!

https://braukaiser.com/wiki/index.php/Starch_Conversion

This paper is about the difference between gel temps and the slightly higher "pasting" temps. It concluded that pasting temps would be the optimal dough-in range. Hence the need for some cold strike water to get the temps down to beta temp levels.

https://pmc.ncbi.nlm.nih.gov/articles/PMC8391644/

 

[Broothru]

That would be a good approach. In reality, you do not want to spend very long at 150F as it denatures beta. I am restrained by my low oxygen approach so I would need the cold water to be prepped before adding it. So it would be easier for non-low oxygen brewers. But yes, that would wring the best out of the strategy. I seem to remember gelatinization being a somewhat quick process.

Here are some links for the nerds!

https://braukaiser.com/wiki/index.php/Starch_Conversion

This paper is about the difference between gel temps and the slightly higher "pasting" temps. It concluded that pasting temps would be the optimal dough-in range. Hence the need for some cold strike water to get the temps down to beta temp levels.

https://pmc.ncbi.nlm.nih.gov/articles/PMC8391644/

I brew low oxygen as well. The evening before I brew, I prep my mash water by filling the AIO nearly to the brim, heat the water to 104F and stir in 20 grams of dextrose and 20 grams of bread yeast. Let the yeast proof at 104F with circulation on for an hour to scavenge O2. Turn off the power, cover the AIO, and let it sit overnight.

The yeast consumes virtually all the dissolved oxygen, and will continue to maintain zero D.O. for several days as long as the yeast isn’t denatured by heat. In the morning I heat the water to strike temp while crushing grains, add whatever brewing salts I’ve calculated, and then drain off 3~4 gallons of the treated water. Put the malt pipe and screens, mash in, and return enough of the treated water to cover the grist and float the mash cap. That leaves a gallon or two to heat for sparge.

If I drained a few gallons of treated de-oxygenated water prior to heating to strike temp, I could use that for ‘drift-down’ cooling.

 

[Bassman2003]

Sounds like a decent plan. My setup uses full volume mashing so I heat all of the YOS water and it all goes into the mash. But I could draw some off before heating the full batch amount... I will research the pasting temps from the paper I linked to. It seems to say that 147F would be the ideal dough in temperature (inferring gel temps to be 141F) which seems low to me.

 

[Broothru]

Sounds like a decent plan. My setup uses full volume mashing so I heat all of the YOS water and it all goes into the mash. But I could draw some off before heating the full batch amount... I will research the pasting temps from the paper I linked to. It seems to say that 147F would be the ideal dough in temperature (inferring gel temps to be 141F) which seems low to me.

Yeah, me too. I thought I’d read (somewhere) that gelatinization peaked around 150Ish F, which nearly coincided with b-amylase at the mid to high 140s F. I’m not sure of where limit dextrinase maxes out, but apparently is doesn’t denature until nearer to 160F. That coincides with dextrin favoring mashes topping out at 158F.