Loss of Diastatic Power from Toasting Malt

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TheMadKing

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So I just finished reading Historical German Beers for the Homebrewer. One of the things I don't really care for about the book is the correlation between modern malt and historical malt. He equates:
Pale/yellow/white malt = pilsen
amber malt = vienna
brown malt = munich

I have never experienced a 100% vienna beer or a 100% munich beer that I would consider amber or brown respectively. I would describe vienna as gold and munich as amber.

So in an effort to slightly improve historical accuracy, I am curious about toasting my own malt at home to achieve a little more color. He does point out the fact that these historical malts were apparently able to self-convert, so the must have had some diastatic power remaining. This was his reason for choosing these particular modern malts. I can't help but feeling that the historical malts were darker than these modern ones.

My question is: if I were to toast some vienna malt in my oven, at say 250F, would I completely destroy its diastatic power? Does anyone have any experience with this?
 
I've toasted a few pounds of Vienna malt at 250 degrees for 1 hour, and it makes for a very nice Biscuit/Victory type malt. I measured its pHDI at 5.07. That said, I honestly have no idea what the toasting did to the diastatic power. My guess however is that the toasting process completely destroyed it. Briess data does not indicate any remaining level of diastatic activity for its Victory brand of Biscuit malt.
 
I've toasted a few pounds of Vienna malt at 250 degrees for 1 hour, and it makes for a very nice Biscuit/Victory type malt. I measured its pHDI at 5.07. That said, I honestly have no idea what the toasting did to the diastatic power. My guess however is that the toasting process completely destroyed it. Briess data does not indicate any remaining level of diastatic activity for its Victory brand of Biscuit malt.

Thanks for the feedback! I found another thread where biscuit malt was listed at a diastatic power of 6 Lintner, which would indicate that it is indeed low but not gone. Munich 20L is able to self convert and I would indeed call munich 20 more brown than the standard Munich I we are able to commonly get here in the US. So it must be possible to darken the malt without totally destroying the enzymes.

I guess I may need to do some trial an error with mini mashes and iodine tests to find out what the limit is for toasting
 
I guess I may need to do some trial an error with mini mashes and iodine tests to find out what the limit is for toasting

You might retain some degree of DP by holding the oven temperature at 170 degrees and toasting for 2 or 3 hours vs. holding at 250 degrees for 1 hour. It's got to be a function of the ability of the DP related enzymes to resist denaturing with respect to time held at any given temperature.
 
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You might retain some degree of DP by holding the oven temperature at 170 degrees and toasting for 2 or 3 hours vs. holding at 250 degrees for 1 hour. It's got to be a function of the ability of the DP related enzymes to resist denaturing with respect to time held at any given temperature.

I was thinking the same thing actually. Low temperature for a longer time will slow the rate of enzyme loss, but I can only hope that the rate of loss is not offset by the overall length of time.
 
You might retain some degree of DP by holding the oven temperature at 170 degrees and toasting for 2 or 3 hours vs. holding at 250 degrees for 1 hour. It's got to be a function of the ability of the DP related enzymes to resist denaturing with respect to time held at any given temperature.

I've been doing some research, and there's actually a nice writeup of 18th century british malting techniques on the Shutup about Barclay Perkins blog with some helpful discussion in the comments. It sounds overall like the author of the book that I read was operating on a false premise: That beers produced in medieval times were commonly composed of a single type of malt (i.e. brown beers used 100% brown malt). There is no evidence for this that I can find, especially given the fact that maltsters commonly produced multiple colors of malt in a single batch.

The UK malting technology was about 100 years ahead of the continental malting techniques in terms of using coke and indirect heat vs wood fired kilns. However that only really applies to malting from about 1750 - 1900. Prior to that, malting and kilning appears to have changed very little between ~1000 - 1750 and was done with wood or coal fires kilns that imparted a smokey flavor to most malts that were not sun or air dried. Kilned malts (amber and brown) would have been cheaper due to the quicker turnaround, which makes them attractive, but it's unlikely they were able to self convert as the author seems to assume.

There is no reason why german brewers from the 1400-1600's would have been stuck using a single type of malt, and it seems to me they would have likely used a combination of air-dried malt alongside brown malt from the purely practical point that they needed additional diastatic power to convert the cheaper higher kilned malts.

So it seems that many of the recipes that the author has devised in Historical German Beers are complete bunk, other than the mashing techniques which he describes, which I intend to try.
 
I can't speak to the German malts, but years ago I made a simple malt kiln and produced both a fully diastatic and non-diastatic brown malt, using straw and hornbeam; representing both the 18/19th century versions. The straw kilned malt was not very smokey and when used for 100% of the grist produced a moderately strength beer around 18 SRM. The hornbeam batches were also far less smokey than anticipated and produced a beer with strong "woody" flavors, as if it was oak barrel aged. In both cases, the intense heat resulted in popcorn-like kernels that were highly carbonized and provided much of the color and flavor, but left the malt nearer the top only mildly toasted and still diastatic.
 
I can't speak to the German malts, but years ago I made a simple malt kiln and produced both a fully diastatic and non-diastatic brown malt, using straw and hornbeam; representing both the 18/19th century versions. The straw kilned malt was not very smokey and when used for 100% of the grist produced a moderately strength beer around 18 SRM. The hornbeam batches were also far less smokey than anticipated and produced a beer with strong "woody" flavors, as if it was oak barrel aged. In both cases, the intense heat resulted in popcorn-like kernels that were highly carbonized and provided much of the color and flavor, but left the malt nearer the top only mildly toasted and still diastatic.

Really interesting, how deep was your malt bed and can you describe your kiln a bit?

I read about blown malt like you're describing, and I had actually considered a color gradient in a kiln, except for the fact that most historical sources I've been able to find clearly indicate the malt was stirred during the kilning process so I would be surprised if a gradient is historically accurate.
 
Since you've started down the rabbit hole of brown and blown malt, you might find this book interesting. Foster dives quite deeply into the history of the malt used in the porter/stout era and how it differs from today's offerings. It's a great book: it's both useful and pleasant to read. But I'm a blushing Terry Foster fan boy. He's dreamy and I'm not ashamed to admit it.

Also, if you do choose to toast your own malt, be sure to let it sit for a week or two after toasting it. It does make a difference.
 
Since you've started down the rabbit hole of brown and blown malt, you might find this book interesting. Foster dives quite deeply into the history of the malt used in the porter/stout era and how it differs from today's offerings. It's a great book: it's both useful and pleasant to read. But I'm a blushing Terry Foster fan boy. He's dreamy and I'm not ashamed to admit it.

Also, if you do choose to toast your own malt, be sure to let it sit for a week or two after toasting it. It does make a difference.

Thanks for the link and the tip! I'll give it a good read and I slobber at the thought of reading any well written historical text.

I did actually stumble across a number of your posts here on HBT on the subject and I believe you're a treasure to historical British brewing, so thanks again for your insights!

UK ales are dear to me but traditional German offerings are also there as well. These UK sources are helpful in providing context for the transition to coke kilns on the continent, but I'm afraid they don't really reflect the state of continental malts prior to the mid 19th century. For example the original Munich lagerbier was (according to the author of the book referenced in my original post) made from 100% Braunbier malz. If I attempted to make this beer using 100% UK historical brown malt, I strongly suspect that I would get a very different beer than if I simply toasted some Munich to 20L or so and crossed my fingers that it would still self convert. Though I would love to get your thoughts on this.

Cheers
 
Those were some very kind words. Thank you.

My thoughts on this interesting topic are limited. My experience with toasting/roasting malts was driven by practical necessity--there just wasn't much UK malt available at the time. By contrast, the core German/German-style malts were (mostly) available. While I was just trying to gin up some British hooch, you're taking a stab at legit experimental archaeology, which is way cooler.

I've been mucking around in my library this morning and I can't seem to find much regarding diastatic power in the production of malt. In this book , John Mallett cautions that moisture content can greatly accelerate the degradation of diastatic power when kilning. In a separate paragraph he notes that when the malt reaches 10% moisture it is ready for kilning. He also states that the malt must be turned during the kilning process, but I've found this to be impractical with the cookie sheet in the oven technique. A short paragraph and a couple sentences in the following paragraph is about the extent of what he has to say, unfortunately.

From a homebrew (rather than Mallett's industrial, perspective) Randy Mosher has a short but very dense section on roasting your own malt in Radical Brewing. Whereas Mallett suggests that longer duration roasting at lower temperatures is the industry norm, Mosher suggests shorter durations at higher temps. This is in line with what I was doing. There were a lot of reasons for this, but the primary driver of my decision to focus on 30min-2hr roasts was the goal of gaining at least some consistency in a very inexact process. Mosher also recommends using your nose when gauging your progress. I couldn't agree more! You can't go by taste, home roasted malt really needs a week or two to mellow out, and you likely already appreciate that roasted/toasted malts tend to be a lot darker in the mash tun than in the grain bin, so that limits the usefulness of your eyes. Mosher includes a chart with times, temperatures, and descriptions of the results. I think 30min at 350, 40min at 375, and 30min at 400 is in your target zone. Mosher also suggests that soaking your malt for up to 2hrs prior to roasting can help develop flavors. This would never have occurred to me, it sounds like a mess--but I don't doubt him, he knows his stuff.

Unfortunately, I think Mosher brings us back, at least partially, to the UK perspective. From the German perspective, at least you can take comfort in knowing that if you start with pils, Vienna, or light Munich, your starting malt has some enzymes to burn. Perhaps a good starting point would be to roast some malt at the short duration/low temp end of the spectrum and use it as 25% of your grist, Munich being the other 75%. This will give you a very good idea of what you're working with, and will also likely impress upon you that a little home roasted malt goes a long way.

You have me interested! Unfortunately, I had to cut short my mucking around in the library because I need to go to work (thank you, COVID-19 for the honor of getting the night shift). I'll do some more mucking around tomorrow and see what shakes loose.
 
So it must be possible to darken the malt without totally destroying the enzymes.


i have to admit i skipped over a lot....but low and slow....when i make my munich malt, which i have no idea about litners or any crap like that...but 8lb's of it would be able to convert 5lb's of white flour......and it was 'kilned' at 200f for 12 hours......this is what a beer made from 100% of it looks like....

100_0387.JPG


i would say that's pretty brown!
 
Those were some very kind words. Thank you.

My thoughts on this interesting topic are limited. My experience with toasting/roasting malts was driven by practical necessity--there just wasn't much UK malt available at the time. By contrast, the core German/German-style malts were (mostly) available. While I was just trying to gin up some British hooch, you're taking a stab at legit experimental archaeology, which is way cooler.

I've been mucking around in my library this morning and I can't seem to find much regarding diastatic power in the production of malt. In this book , John Mallett cautions that moisture content can greatly accelerate the degradation of diastatic power when kilning. In a separate paragraph he notes that when the malt reaches 10% moisture it is ready for kilning. He also states that the malt must be turned during the kilning process, but I've found this to be impractical with the cookie sheet in the oven technique. A short paragraph and a couple sentences in the following paragraph is about the extent of what he has to say, unfortunately.

From a homebrew (rather than Mallett's industrial, perspective) Randy Mosher has a short but very dense section on roasting your own malt in Radical Brewing. Whereas Mallett suggests that longer duration roasting at lower temperatures is the industry norm, Mosher suggests shorter durations at higher temps. This is in line with what I was doing. There were a lot of reasons for this, but the primary driver of my decision to focus on 30min-2hr roasts was the goal of gaining at least some consistency in a very inexact process. Mosher also recommends using your nose when gauging your progress. I couldn't agree more! You can't go by taste, home roasted malt really needs a week or two to mellow out, and you likely already appreciate that roasted/toasted malts tend to be a lot darker in the mash tun than in the grain bin, so that limits the usefulness of your eyes. Mosher includes a chart with times, temperatures, and descriptions of the results. I think 30min at 350, 40min at 375, and 30min at 400 is in your target zone. Mosher also suggests that soaking your malt for up to 2hrs prior to roasting can help develop flavors. This would never have occurred to me, it sounds like a mess--but I don't doubt him, he knows his stuff.

Unfortunately, I think Mosher brings us back, at least partially, to the UK perspective. From the German perspective, at least you can take comfort in knowing that if you start with pils, Vienna, or light Munich, your starting malt has some enzymes to burn. Perhaps a good starting point would be to roast some malt at the short duration/low temp end of the spectrum and use it as 25% of your grist, Munich being the other 75%. This will give you a very good idea of what you're working with, and will also likely impress upon you that a little home roasted malt goes a long way.

You have me interested! Unfortunately, I had to cut short my mucking around in the library because I need to go to work (thank you, COVID-19 for the honor of getting the night shift). I'll do some more mucking around tomorrow and see what shakes loose.

Well now I'm going to call it experimental archaeology! Something I'm also passionate about.

I have, thanks to you, purchased 4 new books for my own library this morning including Mosher's radical brewing, so I'll be looking to his information as a place to start.

To get really experimental though, I would probably need to start with malting my own raw barley but that sounds intimidating. I think for now I'll start with pilsen or vienna as a base and attempt some roasting mashing and iodine tests to look at their ability to convert. This will also require a spreadsheet no doubt, and some photos to post on here.

One point of interest in your post above: the idea of soaking the grist prior to roasting is likely creating a form of semi-crystal malt. Enzymes, while less active at low temperatures, are indeed still active. So soaking base malt in cool water for several hours seems likely to cause some conversion to occur within the kernals which is then caramelized producing the flavors that Mosher observed. Mallets observation that high moisture content would degrade enzymes faster while kilning also seems to be a point against the soak the Mosher suggests.

I need to think about experiment design here and organize my thoughts somewhat before I start applying heat to grain.

I'm a huge believer in convergent technology, so I believe with enough trial an error I'll be able to produce a self-converting german malt that produces a brown wort. And if I can't then it would be evidence in favor of my original thought, that the german brewers of history would have mixed portion of their kilned brown malt with high diastatic air-dried or sun-dried malt to produce their wort.
 
i have to admit i skipped over a lot....but low and slow....when i make my munich malt, which i have no idea about litners or any crap like that...but 8lb's of it would be able to convert 5lb's of white flour......and it was 'kilned' at 200f for 12 hours......this is what a beer made from 100% of it looks like....

View attachment 696667

i would say that's pretty brown!

Indeed it is brown.

Can you tell me a bit more about what you did to produce that malt and that beer?

How did you kiln it? Why did you brew with white flour? and Was that brown beer any good?
 
Can you tell me a bit more about what you did to produce that malt and that beer?

SURE! :) i sprouted barley in my spare bathtub until most of the acrospires are sticking out of the husks....dryed for a day with a box fan blowing air on them...threw the barley in the over at 170f, which if my IR therm is to believed is actually 200f, for 12 hours, or until the oven times out and shuts it's self off....fiddle it around through my fingers to break off the rootlets, then blow them off to clean.....brew as usual.....(but a second step at 162f, after saccirfication, helps with effec)

How did you kiln it? Why did you brew with white flour? and Was that brown beer any good?

already answered the first....i brewed with white flour because i'm cheap, and at the time i was still using my food dehydrator instead of the box fan method....so could only fit 8lb's in it....and yes both the white flour, and THAT brown beer were good, just gets boring after a while....not much you can do with a recipe that starts off like that......that's why i modded my oven to go down to 150f for kilning, now i can make pale malt, and different beers again!.... :mug:
 
SURE! :) i sprouted barley in my spare bathtub until most of the acrospires are sticking out of the husks....dryed for a day with a box fan blowing air on them...threw the barley in the over at 170f, which if my IR therm is to believed is actually 200f, for 12 hours, or until the oven times out and shuts it's self off....fiddle it around through my fingers to break off the rootlets, then blow them off to clean.....brew as usual.....(but a second step at 162f, after saccirfication, helps with effec)



already answered the first....i brewed with white flour because i'm cheap, and at the time i was still using my food dehydrator instead of the box fan method....so could only fit 8lb's in it....and yes both the white flour, and THAT brown beer were good, just gets boring after a while....not much you can do with a recipe that starts off like that......that's why i modded my oven to go down to 150f for kilning, now i can make pale malt, and different beers again!.... :mug:

Many thanks! your bathtub sounds a bit sketchy, but the rest sounds perfectly reasonable!
 
Many thanks! your bathtub sounds a bit sketchy, but the rest sounds perfectly reasonable!


it gets a bleach soak, and a scrub down between batches.....and as mentioned, unused for bathing.....if you're just doing a five gallon batch a storage tote will work too....
 
Really interesting, how deep was your malt bed and can you describe your kiln a bit?

I read about blown malt like you're describing, and I had actually considered a color gradient in a kiln, except for the fact that most historical sources I've been able to find clearly indicate the malt was stirred during the kilning process so I would be surprised if a gradient is historically accurate.

The kiln was made of brick and stainless mesh wire, heat source was maybe 1 foot from the the grain. At the time, I was more interested in seeing the effect hornbeam wood had on the malt flavor, as it produces little smoke and burns hot/clean. The woodiness imparted by the wood was the most interesting part of the experiment. The historical sources mention the beer "tastes of the wood," with everyone assuming that meant it was smokey. I don't think that may be the case. As for turning the malt (it was maybe 4-5" deep) the malt was turned constantly, but again the popcorn effect prevented all of the malt from coming in direct contact with the wire mesh and prevented it all from scorching.
 
The kiln was made of brick and stainless mesh wire, heat source was maybe 1 foot from the the grain. At the time, I was more interested in seeing the effect hornbeam wood had on the malt flavor, as it produces little smoke and burns hot/clean. The woodiness imparted by the wood was the most interesting part of the experiment. The historical sources mention the beer "tastes of the wood," with everyone assuming that meant it was smokey. I don't think that may be the case. As for turning the malt (it was maybe 4-5" deep) the malt was turned constantly, but again the popcorn effect prevented all of the malt from coming in direct contact with the wire mesh and prevented it all from scorching.

Thanks for that! If you have any photos that you wouldn't mind sharing that would be great.
 
Since you've started down the rabbit hole of brown and blown malt, you might find this book interesting. Foster dives quite deeply into the history of the malt used in the porter/stout era and how it differs from today's offerings. It's a great book: it's both useful and pleasant to read. But I'm a blushing Terry Foster fan boy. He's dreamy and I'm not ashamed to admit it.

Also, if you do choose to toast your own malt, be sure to let it sit for a week or two after toasting it. It does make a difference.

So I've just finished this book, and I did enjoy it, but I found a few things that raised my eyebrow. I'll start by saying, I realize that Terry was writing 20 years ago and much has changed, but nonetheless they call into question his overall knowledge and understanding of the malt creation process.

He uses the terms "kilning" and "roasting" interchangably and these are distinct processes done in totally separate machines. Kilning is the drying process and is done at 150 - 175F, whereas roasting is done with a roasting roller and is heated much higher and the maltster can spray water or otherwise manage the moisture content of the grain being roasted. The flavor difference is that kilned malts develop malanoidins whereas roasted malts create caramelization (temperatures above 230F).

Because of this, he doesn't recognize the difference between highly kilned malts and crystal malts. He actually refers to a highly kilned 60L munich malt as being equivalent to a crystal malt. Crystal malts require starch conversion within the green malt at 150F and then roasting immediately while the grains are still wet. Whereas a 60L munich would result in toasty bread flavors, a crystal 60 will add caramel flavors and dextrine.

So this means his entire discussion of brown and amber malts is questionable because these malts were originally kilned malts and not dextrinized and not roasted.

I just recently listened to an episode of Master Brewers Podcast (episode 177 I believe) where they go through these processes in great detail with maltsters and it was very illuminating. I had no appreciation for the complexity and the number of variables a maltster can manipulate in order to achieve different flavors.
 
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Hey guys, I'm resurrecting this necro-thread, as my local club is throwing a so-called SMASH beer competition (single malt and single hop), and I aim to win. As an experiment, I have decided to try to attempt to make a beer of 100% home-roasted diastatic amber malt. And I have a pound of Tettnanger laying around so I'll probably use that, with a lager yeast, to make some manner of a dunkel or bock. If you all have any experiences to share, I am all ears... at least for the next couple of days. I will probably bake / "roast" the malt on Wednesday 9/29, and brew on Thursday evening 9/30, as I will be gone over the weekend.

Based on a wee bit of online research, besides finding this thread (which is really awesome), I found the following link:

https://brewerylane.com/beer/beer-learning-centre
Based on this, my "Plan A" proposed process looks a little something like this:

1) Place the malt into 9 x 13 inch pans as necessary, aiming for a depth of about 1.5 to 2 inches. I will NOT be stirring periodically during the bake. I'm doing this on purpose to try to roast the corners and edges of the grains a little more then the insides -- call me crazy but I actually want my malt to end up NOT homogeneous. If it's a little more toasted in the corners, but the insides still have more enzymes, great!

2) Set oven to 170 F (the lowest allowed on my oven) and bake for about 15 minutes.

3) Raise oven to 200 F for 30 minutes.

4) Raise oven to 230 F for 30 minutes.

Done.

OR, would perhaps "Plan B" turn out better? It would certainly be easier. It's based on a different link, which includes really cool experimental data suggesting that malt roasted at 390 F for 45 minutes still has a tiny bit of enzymes?!

http://edsbeer.blogspot.com/2015/02/making-diastatic-brown-malt.html
So for this one I'd propose:

1) Same 2-inch depth in pans.

2) Set oven to 375 F and bake for 40 minutes. Slightly less than the limit to try to ensure enzyme preservation, and who knows, maybe my oven (or yours) is a little "fast" (i.e., hotter than it reads).

Done.

Some sources suggest aging the roasted malt for ~2 weeks prior to use, but others say there are things to be gained by using it right away. In any case, I don't have the luxury of waiting -- the beer has to be ready to drink by first week of November. So I'm brewing right away no matter what.

Thoughts!? I'll be sure to update later on appearance, aromas, efficiency, attenuation, flavor, etc.

Cheers!
 
I've only toasted malt once. I made a very nice Biscuit/Victory/Amber type malt via toasting 2 pounds of Vienna malt at 250 degrees for 1 hour. But I never intended for it to have any remaining diastatic power, and have no Idea if it did. My presumption is that it did not. My avatar shows me testing its pHDI.

I'd be leary of either of your profiles leaving sufficient diastatic power for self conversion. I would add some Amylase Enzyme to it.

The 375 degree method particularly scares me, as my guess is that it would yield a nasty bitter tasting result.
 
Hey guys, I'm resurrecting this necro-thread, as my local club is throwing a so-called SMASH beer competition (single malt and single hop), and I aim to win. As an experiment, I have decided to try to attempt to make a beer of 100% home-roasted diastatic amber malt. And I have a pound of Tettnanger laying around so I'll probably use that, with a lager yeast, to make some manner of a dunkel or bock. If you all have any experiences to share, I am all ears... at least for the next couple of days. I will probably bake / "roast" the malt on Wednesday 9/29, and brew on Thursday evening 9/30, as I will be gone over the weekend.

Based on a wee bit of online research, besides finding this thread (which is really awesome), I found the following link:

https://brewerylane.com/beer/beer-learning-centre
Based on this, my "Plan A" proposed process looks a little something like this:

1) Place the malt into 9 x 13 inch pans as necessary, aiming for a depth of about 1.5 to 2 inches. I will NOT be stirring periodically during the bake. I'm doing this on purpose to try to roast the corners and edges of the grains a little more then the insides -- call me crazy but I actually want my malt to end up NOT homogeneous. If it's a little more toasted in the corners, but the insides still have more enzymes, great!

2) Set oven to 170 F (the lowest allowed on my oven) and bake for about 15 minutes.

3) Raise oven to 200 F for 30 minutes.

4) Raise oven to 230 F for 30 minutes.

Done.

OR, would perhaps "Plan B" turn out better? It would certainly be easier. It's based on a different link, which includes really cool experimental data suggesting that malt roasted at 390 F for 45 minutes still has a tiny bit of enzymes?!

http://edsbeer.blogspot.com/2015/02/making-diastatic-brown-malt.html
So for this one I'd propose:

1) Same 2-inch depth in pans.

2) Set oven to 375 F and bake for 40 minutes. Slightly less than the limit to try to ensure enzyme preservation, and who knows, maybe my oven (or yours) is a little "fast" (i.e., hotter than it reads).

Done.

Some sources suggest aging the roasted malt for ~2 weeks prior to use, but others say there are things to be gained by using it right away. In any case, I don't have the luxury of waiting -- the beer has to be ready to drink by first week of November. So I'm brewing right away no matter what.

Thoughts!? I'll be sure to update later on appearance, aromas, efficiency, attenuation, flavor, etc.

Cheers!

Unfortunately I was overcome by work and a new baby and was never able to really set down and try any of this. I still intend to because my annual intraclub single style competition (my biggest and most important beer event every year) choose Scottish ale as the style for 2022.

Competition is fierce and we're lucky enough to have both a grandmaster V and national beer judge to help judge. We've never had a winner who didn't brew at least 3-5 test batches, so I have a good opportunity for some experiments with toasted malt coming up.

Based on everything I've read and Larry and bramlings advice above, if you don't intend to allow your malt to rest, I would stay on the lighter end of toast. Evidently you can get some pretty nasty flavors if you don't rest it, and even professional maltsters rest their malt before selling.

I kind of like your idea of the malt color gradient in the deeper malt bed. It makes a certain amount of sense. I had mentioned this earlier on, but dismissed it because it probably isn't historically accurate since most sources describe stirring the malt bed during the roasting or kilning process

I'll see if I can set aside some time this coming weekend to do a test batch and see what I can figure out
 
I had no idea this existed, thank you!
I thought so, you're welcome! I was also a bit excited when I saw it first. I want to make a London porter with it one day, just this malt, single infusion, 65c, one hop for bittering, that's it. But I haven't found it in Germany yet .. let me know how it works for you!
 
I thought so, you're welcome! I was also a bit excited when I saw it first. I want to make a London porter with it one day, just this malt, single infusion, 65c, one hop for bittering, that's it. But I haven't found it in Germany yet .. let me know how it works for you!
Its not available in the u.s. Either.. Well damn

Back to making my own
 
Hey guys, I'm resurrecting this necro-thread, as my local club is throwing a so-called SMASH beer competition (single malt and single hop), and I aim to win. As an experiment, I have decided to try to attempt to make a beer of 100% home-roasted diastatic amber malt. And I have a pound of Tettnanger laying around so I'll probably use that, with a lager yeast, to make some manner of a dunkel or bock. If you all have any experiences to share, I am all ears... at least for the next couple of days. I will probably bake / "roast" the malt on Wednesday 9/29, and brew on Thursday evening 9/30, as I will be gone over the weekend.

Based on a wee bit of online research, besides finding this thread (which is really awesome), I found the following link:

https://brewerylane.com/beer/beer-learning-centre
Based on this, my "Plan A" proposed process looks a little something like this:

1) Place the malt into 9 x 13 inch pans as necessary, aiming for a depth of about 1.5 to 2 inches. I will NOT be stirring periodically during the bake. I'm doing this on purpose to try to roast the corners and edges of the grains a little more then the insides -- call me crazy but I actually want my malt to end up NOT homogeneous. If it's a little more toasted in the corners, but the insides still have more enzymes, great!

2) Set oven to 170 F (the lowest allowed on my oven) and bake for about 15 minutes.

3) Raise oven to 200 F for 30 minutes.

4) Raise oven to 230 F for 30 minutes.

Done.

OR, would perhaps "Plan B" turn out better? It would certainly be easier. It's based on a different link, which includes really cool experimental data suggesting that malt roasted at 390 F for 45 minutes still has a tiny bit of enzymes?!

http://edsbeer.blogspot.com/2015/02/making-diastatic-brown-malt.html
So for this one I'd propose:

1) Same 2-inch depth in pans.

2) Set oven to 375 F and bake for 40 minutes. Slightly less than the limit to try to ensure enzyme preservation, and who knows, maybe my oven (or yours) is a little "fast" (i.e., hotter than it reads).

Done.

Some sources suggest aging the roasted malt for ~2 weeks prior to use, but others say there are things to be gained by using it right away. In any case, I don't have the luxury of waiting -- the beer has to be ready to drink by first week of November. So I'm brewing right away no matter what.

Thoughts!? I'll be sure to update later on appearance, aromas, efficiency, attenuation, flavor, etc.

If anyone is interested...

I actually ended up doing a hybrid of both Plans A & B. After starting with Plan A... the effect was basically nil, undetectable. Malt still tasted the same as when I started, and was still pure white inside the kernels, as if all I had done was dry out the malt a bit.

So, I decided to crank up the heat to 375 F, not for 40 minutes, but just 20 minutes. This definitely had a real impact. Very quickly I experienced toasty aromas coming forth from the oven. After the 20 minutes was over, I removed the toasted malt from the oven. Only on the top surface are the husks visibly much darker, but underneath they are only "moderately" darker than when I first started, which makes sense. When splitting the kernels open, I am able to detect just a very very faint tan tinting, no longer pure white.

So, tomorrow I shall brew with this toasted malt at 100% of the grist, and hope there is some enzyme content remaining for conversion. I do plan for a "long" mash of about 75 minutes, hopefully that will help too (-- usually I mash for 45 minutes, based on MUCH experimentation and experience for >130 batches). If my efficiency or attenuation is poor, I guess we'll have our answer about diastatic power after 20 minutes at 375 F, but I'll just go ahead and ferment it out regardless because I'm crazy like that.

:ban:
 
If anyone is interested...

I actually ended up doing a hybrid of both Plans A & B. After starting with Plan A... the effect was basically nil, undetectable. Malt still tasted the same as when I started, and was still pure white inside the kernels, as if all I had done was dry out the malt a bit.

So, I decided to crank up the heat to 375 F, not for 40 minutes, but just 20 minutes. This definitely had a real impact. Very quickly I experienced toasty aromas coming forth from the oven. After the 20 minutes was over, I removed the toasted malt from the oven. Only on the top surface are the husks visibly much darker, but underneath they are only "moderately" darker than when I first started, which makes sense. When splitting the kernels open, I am able to detect just a very very faint tan tinting, no longer pure white.

So, tomorrow I shall brew with this toasted malt at 100% of the grist, and hope there is some enzyme content remaining for conversion. I do plan for a "long" mash of about 75 minutes, hopefully that will help too (-- usually I mash for 45 minutes, based on MUCH experimentation and experience for >130 batches). If my efficiency or attenuation is poor, I guess we'll have our answer about diastatic power after 20 minutes at 375 F, but I'll just go ahead and ferment it out regardless because I'm crazy like that.

:ban:

Thanks for reporting back! I plan on toasting 2 lb of American 2 row this weekend to use in a Scottish ale down the line so I will definitely start with the higher temperature
 
Thanks for reporting back! I plan on toasting 2 lb of American 2 row this weekend to use in a Scottish ale down the line so I will definitely start with the higher temperature

I too am toasting American (Briess) 2-row Brewers malt for this experiment. I have toasted Maris otter malt in the past at about 350 F for 20 minutes and the result tasted positively like PEANUTS. In fact, the reason I am using American 2-row this time is to see what difference it makes. And I chose not to use German Pilsner malt because to my palate the raw grain seems grassy and not the same breadiness that I get from American, and I did not want to risk having any grassiness in this particular batch.

My toasted American malt today tastes like… toast and Cheese-Nip crackers, but without the cheese! To my palate, this is right in line with how I perceive raw Vienna malt. So I have high hopes.
 
If you look at my avatar photo you can easily see that toasting Vienna malt for 60 minutes at 250 degrees F. made for a distilled water Mash at about 18 SRM as to it's color, and also a measured 5.07 pHDI. I can't imagine what the SRM color and pHDI results would have been if this had been done at 375 degrees F. But I do know that a mash made from straight untoasted Vienna malt yields closer to a ballpark 6 SRM final color.
 
We shall soon find out. I will post pictures late tonight, probably around 11pm CDT (Chicago time). Keep in mind, this is toasted Briess brewer's 2-row malt, which I imagine will turn out similar to Vienna or a light Munich of 10-15L. I'm basically aiming for a Vienna or Munich dunkel style, so a copper-ish sort of color would be my goal. I think I'll get there.
 
Mash is halfway done. Conversion is DEFINITELY happening just fine. Nice toasty and nutty aromas, and deep amber to light copper color. Began with a pH goal of 5.6. Actual is 5.3. So indeed, the pH is much lower than a standard base malt. I am going to let it ride at 5.3.
 

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All done. OG is 1053 for a brewhouse efficiency of 81%. Not too shabby. The wort tastes quite toasty and slightly burnt but I’m OK with that. Maybe toasted malts really do benefit from a week or two of aging to mellow out. But I think this is going to be good anyway. I love the deep orange to copper color. I figure it is about 15 SRM and 15 L for the malt itself. Sparging was kind of a pain. After the crush I noticed the husks were pretty well destroyed, must’ve been due to the drying process yesterday. Next time I would condition the grains to avoid this. Overall a pretty good brew day.

Some pics. The lighting is bad. The lightest color picture where held up to a light bulb seems maybe closest to the actual color, or it is someplace in between. Do you like my pickle jar fermenters? I use them on almost every batch. One jar has S-189 at room temp, the other Diamond lager at about 60 F or as cold as the basement will go this October (in Wisconsin).

Cheers.
 

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I'm doing my first test today. As a baseline I'm following the advice of Randy Mosher and I soaked the malt for a few minutes, and I'm baking for 40 minutes at 375.

So far so good and it smells great
 
I'm doing my first test today. As a baseline I'm following the advice of Randy Mosher and I soaked the malt for a few minutes, and I'm baking for 40 minutes at 375.

So far so good and it smells great

The grain picked up a nice biscuit/light toast flavor at 40 minutes but the moisture content is still quite high.

It tastes great but I'm worried about its shelf stability with the moisture this high. It's still cooling so I hope it continues to dry

The flavor is best compared to melanoidin I think
 
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