Unconventionally activating alpha amylase.

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EdmontonBoil

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I'm in my first six months of brewing all grain and tried to tackle a step mash for the first time a couple days ago, making hefeweizen. It didn't go as planned, I ended up at too low of a temp, and I tried to jerry-rig a solution to activate the alpha amylase: I'd like to know whether people think any part of what I made up on the fly will work.

I was initially trying to do a protein rest around 130. I ended up hovering around 138, trying to cool it down for the entirety of the protein rest--and only got down to about 134 by the end. I then raised the temperature by decocting some of the wort, but instead of hitting my target temp of 152, I only raised the temperature to 142. I was brewing while in the middle of a zoom meeting and couldn't step away to attend to the situation, so it sat at this lower temperature for about 45 minutes--which should have activated the beta amylase, but is definitely too low for alpha, as far as I know. I didn't want to decoct again at this point in time (I didn't actually want the brew to last all day), so I decided to take a gamble, drain the wort, batch sparge at a higher temperature, and hold it there for another 20 minutes or so (at about 158 degrees), in the hopes of activating the alpha amylase. Meanwhile, I started to heat the first half of the wort, but as I went through the 155-170 range I slowed down the heating process and again held it there for about 20 minutes in the event that there were enzymes in the wort itself that could work to produce some shorter sugars for the yeast. (Ok -- a second decoction here probably wouldn't have taken any longer, but I was thinking on the fly.)

The sparge pulled way more sugar out of the grist than I expected--only about ten points below the initial mash--so something seemed to be happening. But my question is: is there any way that either the extended sparge or the slow heating of the wort will do anything new to activate alpha amylase that wasn't accomplished in the initial mash?

So far, the fermentation isn't kicking in very quickly, so that might be an indication that I don't have very fermentable sugars in my wort. ...it also might mean that recycling the yeast from my brother's brew last week isn't actually working like I thought it would.
 

monkeymath

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Hm, interesting scenario. Instead of decocting, you also could have added hot water to the mash to raise the temperature. Resting the drained off wort was probably a good call.

I suppose you didn't take an iodine test? It's simple enough to do and tells you whether the conversion was (more or less) complete, very convenient in such a situation. Did you hit your target OG?

142 is certainly low for alpha-amylase, but you'll still have some alpha-amylase activity, even if it's well-below its temperature optimum. It's just hard to say how much in fact. Mash pH might also have an influence on how much activity you actually got.

At this point, it's just a guessing game whether the starch conversion was complete. Attenuation and turbidity of the resulting beer might be an indication of what happened. And if you like the beer, it doesn't really matter imo. Generally speaking, brewing takes so much time that half-assing part of the brew day to save a bit of time just isn't worth it imo - I myself often rush things when something doesn't go as planned, and I always regret it afterwards.
 

Velnerj

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What's your set up like? Are you propane heating with biab? Using a cooler? Or some other method?

You could upgrade to an electric all in one system, or try a sous vide thingy to help raise and control the mash temp. To lower mash temp just add cold water.
 

doug293cz

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What were your strike water volume, sparge water volume, grain bill weight, post-boil volume and OG? From these data points we can get a good estimate of how your mash performed.

The enzymes in a mash are mostly in the liquid wort, so enzyme action definitely took place in your first runnings as you slowly heated them. Due to the low temp and short rest before your first run-off, gelatinization of the starch was most certainly incomplete, so when you added sparge higher temp sparge water and let it rest, you basically ran a second mash, allowing more complete gelatinization of the starch. this is why your second runnings SG was higher than expected. (Gelatinization is the rate limiting step for conversion of starch to sugar. The enzymes cannot act on the starch until the starch is gelatinized.)

There is no specific "activation temperature" for enzyme action. Remember that the biological purpose of the enzymes is to convert starch to sugar at, or slightly below, room temperature to allow the seeds to germinate and grow until leaves are formed so photosynthesis can start feeding the plant. The enzymes work faster as the temperature gets higher. The "so-called" optimum temperatures are basically the highest temps where the enzymes last long enough to complete their job before they get denatured. For mashing you want to get it done in a reasonable amount of time (1 - 2 hrs), so you look for a temp that will gelatinize all the starch in somewhat less than that amount of time, and also that the enzymes won't all be denatured before the end of the mash. Gelatinization that occurs after the enzymes have all been denatured will only leave you with more starch in the wort, not fermentable sugar.

I would highly recommend against attempting to multitask (especially with a higher priority task) while attempting the most complicated mash method (decoction.)

Brew on :mug:
 
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EdmontonBoil

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Thanks for the responses! I'm still just starting to figure out the mechanics of the mash: I'd not heard of gelatinization yet. Am I understanding that the direct action of the hot water is what gelatinizes the starch, allowing the enzymes to break down the starch into sugar?

And yes--point taken regarding decoction. :)

My setup is a cooler and a 10 gallon pot with an electric element. I'm thinking about upgrading to a fully electric system at some point, but this is letting me get my hands dirty with AG--and as with this week's brew, make some mistakes and see what happens.

Here are the numbers. They're close but not exact.

Strike water volume: 20 L
Sparge water volume: 14 L + 4.5 L (I actually did a second sparge and slightly longer boil when I saw how much sugar was still in the grist)
Grain bill: 6lbs wheat, 6lbs 2 row
Post-boil volume: 25 L
OG: 1.052
 

doug293cz

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Thanks for the responses! I'm still just starting to figure out the mechanics of the mash: I'd not heard of gelatinization yet. Am I understanding that the direct action of the hot water is what gelatinizes the starch, allowing the enzymes to break down the starch into sugar?

Yes. Gelatinization is what happens when you cook rice or oatmeal. Basically the starch absorbs water, which expands and opens up the starch granule structure, and the starch chains get surrounded by water. Having the starch chains surrounded by water is required for two reasons:
  1. The enzymes need to be able to move around and attach themselves to the starch chains, and they can't do this within the original dense starch granule structure.
  2. Breaking a glucose to glucose bond in the starch chain requires the addition of a water molecule at the bond site, the water molecule gets split apart, a hydrogen atom ends up on one of the resulting smaller carbohydrate chunks, and the OH end up on the other resulting carbohydrate chunk. This splitting with the consumption of a water molecule is known as hydrolysis. The resulting carbohydrate chunks can be simple sugars, more complex sugars, dextrins, or just smaller starch chains, depending on the starting starch and the particular enzyme involved. The enzymes catalyze the hydrolysis reactions.
So, before you can hydrolyze the starch to create fermentable sugars, you have to gelatinize the starch. The starch doesn't all gelatinize at once - it starts at the surface of the grits and starch granules and proceeds towards the center. Once some of the starch is gelatinized, the enzymes can start the hydrolysis. The products of hydrolysis are soluble, so they go into solution and move away from the surface of the grits/granules, allowing more of the starch to be more easily gelatinized.

To achieve 100% conversion, you first have to achieve 100% gelatinization, and then enough hydrolysis so that all of the hydrolysis products are soluble. At this point your wort has reached its maximum SG, but not maximum fermentability. You get continued enzyme action, increasing wort fermentability, until all of the original starch has been hydrolyzed to fermentable sugar and limit dextrins, or the enzymes are denatured by time or heating.


And yes--point taken regarding decoction. :)

My setup is a cooler and a 10 gallon pot with an electric element. I'm thinking about upgrading to a fully electric system at some point, but this is letting me get my hands dirty with AG--and as with this week's brew, make some mistakes and see what happens.

Here are the numbers. They're close but not exact.

Strike water volume: 20 L
Sparge water volume: 14 L + 4.5 L (I actually did a second sparge and slightly longer boil when I saw how much sugar was still in the grist)
Grain bill: 6lbs wheat, 6lbs 2 row
Post-boil volume: 25 L
OG: 1.052
I plugged your numbers into my mash and lauter simulator spreadsheet, and you didn't do too badly. Your mash efficiency came out at about 78%. Your conversion efficiency however, was only about 85%, and this is most likely due to the short mash time at relatively low temperature. Had your process achieved 100% conversion, your OG would have been about 1.060.

One thing I noticed is that you seem to have boiled off a lot of water - ~2 gal (4 L). Either that or your volume numbers are off, or your grain absorption is higher than typical. Most brewer boil off between 0.75 and 1.5 gal for a ~5 gal batch.

Brew on :mug:
 
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EdmontonBoil

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That spreadsheet is terrific! You accurately reverse-engineered what BeerSmith had as my intended target gravity, which was 1.061.

And yes, my boil tends to be pretty vigorous. I generally lose about 1.5 g/hr. This boil was about 75 minutes, so... close to 2 gallons.

I'm assuming that getting higher conversion rates goes back to optimizing enzyme action?
 

doug293cz

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That spreadsheet is terrific! You accurately reverse-engineered what BeerSmith had as my intended target gravity, which was 1.061.

And yes, my boil tends to be pretty vigorous. I generally lose about 1.5 g/hr. This boil was about 75 minutes, so... close to 2 gallons.

I'm assuming that getting higher conversion rates goes back to optimizing enzyme action?
Thanks, I have a lot of fun with it, and find it very useful.

Higher conversion is mostly about getting more complete gelatinization. Optimizing enzymes is more useful for getting higher fermentability. Unless pH, or temperature is way off, adequate enzyme activity isn't usually a problem.

Brew on :mug:
 

doug293cz

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Any articles you recommend on improving gelatinization? (Or any tips?)
Not specifically on gelatinization. However, shortly after gelatinization is complete, the wort in the mash will reach its maximum SG, as there is nothing more left to go into solution. The last of the long chain insoluble starches to get gelatinized very quickly get cut up into shorter chain soluble starches by the alpha amylase.

The starch in all grains is not completely the same, and some is more difficult to gelatinize than others. The more difficult starches will require more time, or higher temperature for the same time, to get the same amount of gelatinization. The best way to know what's going on is to monitor the SG of the wort during the mash, which is most easily done using a refractometer. When the SG stops increasing with samples taken 15 minutes apart, your mash is basically done. To get accurate results, you need to insure that all of the wort is homogenized prior to taking a sample, usually by aggressive stirring or recirculation of the mash. Malt pipe systems, like some of the all-in-one electric units present unique challenges to getting the wort homogenized.

Maximum fermentability is achieved some minutes after the completion of gelatinization, as it takes some time for the amylase enzymes to finish completely chopping up the last of the starch to be gelatinized.

Brew on :mug:
 

RM-MN

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That spreadsheet is terrific! You accurately reverse-engineered what BeerSmith had as my intended target gravity, which was 1.061.

And yes, my boil tends to be pretty vigorous. I generally lose about 1.5 g/hr. This boil was about 75 minutes, so... close to 2 gallons.

I'm assuming that getting higher conversion rates goes back to optimizing enzyme action?

Why? The boil doesn't need to be vigorous and for most beers you wouldn't need that long of a boil. Mine sometimes go longer than I intend because I leave and don't get back as soon as I intend but most of the time I only boil for 30 minutes.
 

Hopalong

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I'm in my first six months of brewing all grain and tried to tackle a step mash for the first time a couple days ago, making hefeweizen. It didn't go as planned, I ended up at too low of a temp, and I tried to jerry-rig a solution to activate the alpha amylase: I'd like to know whether people think any part of what I made up on the fly will work.

I was initially trying to do a protein rest around 130. I ended up hovering around 138, trying to cool it down for the entirety of the protein rest--and only got down to about 134 by the end. I then raised the temperature by decocting some of the wort, but instead of hitting my target temp of 152, I only raised the temperature to 142. I was brewing while in the middle of a zoom meeting and couldn't step away to attend to the situation, so it sat at this lower temperature for about 45 minutes--which should have activated the beta amylase, but is definitely too low for alpha, as far as I know. I didn't want to decoct again at this point in time (I didn't actually want the brew to last all day), so I decided to take a gamble, drain the wort, batch sparge at a higher temperature, and hold it there for another 20 minutes or so (at about 158 degrees), in the hopes of activating the alpha amylase. Meanwhile, I started to heat the first half of the wort, but as I went through the 155-170 range I slowed down the heating process and again held it there for about 20 minutes in the event that there were enzymes in the wort itself that could work to produce some shorter sugars for the yeast. (Ok -- a second decoction here probably wouldn't have taken any longer, but I was thinking on the fly.)

The sparge pulled way more sugar out of the grist than I expected--only about ten points below the initial mash--so something seemed to be happening. But my question is: is there any way that either the extended sparge or the slow heating of the wort will do anything new to activate alpha amylase that wasn't accomplished in the initial mash?

So far, the fermentation isn't kicking in very quickly, so that might be an indication that I don't have very fermentable sugars in my wort. ...it also might mean that recycling the yeast from my brother's brew last week isn't actually working like I thought it would.
Multitasking works in making homemade beer. In ale and lager brewing you need to be more attentive.
A rest at 130F is used when malt contains a high ppm of Beta Glucan. If the Beta Glucan content is high in malt, it is simple, don't buy the malt. Beta Glucan is listed on a malt spec sheet.
Raising mash temperature from 130 to 152F skips the conversion step. Ale and lager cannot be produced unless conversion occurs. At 142F conversion occurs. So, actually, you didn't screw anything up.
Conversion won't occur unless Alpha works first. Alpha releases simple sugar, glucose during liquefaction. During conversion, which occurs at 140, Beta converts the glucose that Alpha releases from amylose, into fermentable, complex types of sugar, maltose and maltotriose. Maltose and maltotriose are the sugars that produce ale and lager, glucose provides only ABV. When conversion occurs, secondary fermentation takes place due to maltose. Maltotriose is responsible for natural carbonation. Beer doesn't need to be artificially carbonated with sugar or CO2 injection when conversion occurs.
High quality, under modified, low protein, malt is used with the step mash method because the malt is much richer in enzyme content and in starch/sugar content than high modified, high protein, malt. A malt spec sheet comes with every bag of malt, which is used in brewing for determining the quality of malt before malt is purchased, they are online. Modification and protein content are important numbers listed on a malt spec sheet. The higher the modification and protein content in malt, the less suitable the malt is for producing ale and lager. Without a malt spec sheet, a brewer has no idea if the malt is capable of producing ale and lager without the addition of enzymes. Recipes are useless without a malt spec sheet.
When mash boils, hard, heat resistant, complex starch, called amylopectin, bursts and rapidly enters into the mash liquid. The boiling decoction is added back into the main mash, which is resting at a low temperature to preserve enzymes, mash temperature increases, and Alpha liquefies the amylopectin causing dextrinization and gelatinization occur. Amylopectin contains the ingredients that forms body and mouthfeel in ale and lager. The rich starch is thrown away with the spent mash because temperatures in home brew recipes aren't high enough to burst the heat resistant starch, where it enters into the mash liquid, before Alpha denatures.
The decoction method produces very clean and stabile extract, which went down the drain when the extract was batch sparged.
Harvesting yeast probably isn't a good idea at this point in your brewing career. Yeast becomes senile and you won't know when that happens. You don't have the equipment or adequate training to harvest yeast successfully.
 

RPh_Guy

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Multitasking works in making homemade beer. In ale and lager brewing you need to be more attentive.
A rest at 130F is used when malt contains a high ppm of Beta Glucan. If the Beta Glucan content is high in malt, it is simple, don't buy the malt. Beta Glucan is listed on a malt spec sheet.
Raising mash temperature from 130 to 152F skips the conversion step. Ale and lager cannot be produced unless conversion occurs. At 142F conversion occurs. So, actually, you didn't screw anything up.
Conversion won't occur unless Alpha works first. Alpha releases simple sugar, glucose during liquefaction. During conversion, which occurs at 140, Beta converts the glucose that Alpha releases from amylose, into fermentable, complex types of sugar, maltose and maltotriose. Maltose and maltotriose are the sugars that produce ale and lager, glucose provides only ABV. When conversion occurs, secondary fermentation takes place due to maltose. Maltotriose is responsible for natural carbonation. Beer doesn't need to be artificially carbonated with sugar or CO2 injection when conversion occurs.
High quality, under modified, low protein, malt is used with the step mash method because the malt is much richer in enzyme content and in starch/sugar content than high modified, high protein, malt. A malt spec sheet comes with every bag of malt, which is used in brewing for determining the quality of malt before malt is purchased, they are online. Modification and protein content are important numbers listed on a malt spec sheet. The higher the modification and protein content in malt, the less suitable the malt is for producing ale and lager. Without a malt spec sheet, a brewer has no idea if the malt is capable of producing ale and lager without the addition of enzymes. Recipes are useless without a malt spec sheet.
When mash boils, hard, heat resistant, complex starch, called amylopectin, bursts and rapidly enters into the mash liquid. The boiling decoction is added back into the main mash, which is resting at a low temperature to preserve enzymes, mash temperature increases, and Alpha liquefies the amylopectin causing dextrinization and gelatinization occur. Amylopectin contains the ingredients that forms body and mouthfeel in ale and lager. The rich starch is thrown away with the spent mash because temperatures in home brew recipes aren't high enough to burst the heat resistant starch, where it enters into the mash liquid, before Alpha denatures.
The decoction method produces very clean and stabile extract, which went down the drain when the extract was batch sparged.
Harvesting yeast probably isn't a good idea at this point in your brewing career. Yeast becomes senile and you won't know when that happens. You don't have the equipment or adequate training to harvest yeast successfully.

LOL, I'm dying.
 

Hopalong

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Not specifically on gelatinization. However, shortly after gelatinization is complete, the wort in the mash will reach its maximum SG, as there is nothing more left to go into solution. The last of the long chain insoluble starches to get gelatinized very quickly get cut up into shorter chain soluble starches by the alpha amylase.

The starch in all grains is not completely the same, and some is more difficult to gelatinize than others. The more difficult starches will require more time, or higher temperature for the same time, to get the same amount of gelatinization. The best way to know what's going on is to monitor the SG of the wort during the mash, which is most easily done using a refractometer. When the SG stops increasing with samples taken 15 minutes apart, your mash is basically done. To get accurate results, you need to insure that all of the wort is homogenized prior to taking a sample, usually by aggressive stirring or recirculation of the mash. Malt pipe systems, like some of the all-in-one electric units present unique challenges to getting the wort homogenized.

Maximum fermentability is achieved some minutes after the completion of gelatinization, as it takes some time for the amylase enzymes to finish completely chopping up the last of the starch to be gelatinized.

Brew on :mug:
Maximum fermentability has nothing to do with dextrinization and gelatinization. The types of sugar contained in amylopectin are nonfermenting. Pectin is responsible for gelatinization and when gelatinization occurs it is quite noticeable in the mash. The mash jells up.
Producing maximum fermentable extract occurs at 149, 150F. At the temperatures Alpha releases the highest volume of glucose from amylose within one hour. The more glucose the more alcohol. For that reason, moonshiners use the temperatures.
There are two types of starch in malt, simple starch, amylose, and complex starch, amylopectin. Amylose contains simple sugar, glucose, which is responsible for primary fermentation and ABV, nothing more, and sweet tasting, nonfermenting types of sugar. The only purpose of Alpha is to release glucose, which is one of three building blocks of life, from starch, and amylase works quite well at 98.6F. The higher the mash temperature is above 150F, the quicker Alpha denatures leaving the reducing end that forms when Alpha liquefies amylose, longer in length, which produces sweet tasting, low ABV beer. The nonreducing end that forms during liquefaction is glucose.
Complex starch, amylopectin, makes up the tips of malt and it is the richest starch in malt. Amylopectin contains limit dextrin, which are tasteless, nonfermenting types of sugar and pectin. Pectin holds everything in beer together during conditioning and storage. Limit dextrin, pectin and a particular type of protein forms body and mouthfeel in ale and lager. Amylopectin is thrown out with the spent mash in home brewing. The temperatures recommended in recipes aren't high enough to burst the heat resistant, starch, where it enters into the mash liquid, before Alpha denatures. The decoction method takes advantage of amylopectin.
Then, there is conversion, which is skipped in home brewing. Beta turns glucose into maltose and maltotriose, during conversion. During secondary fermentation yeast absorbs maltose and an enzyme in yeast converts the complex sugar back into glucose, which becomes fuel.
Aggressively stirring hot mash aggressively oxidizes beer.
Recirculating hot extract through a grain bed for a long period of time causes over sparge, which extracts tannin. Vorlauf is kept within 10 minutes using a small volume of extract to reduce tannin extraction.
 
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