Alpha rest followed by a beta rest

[jujitsudave]

As the title implies, wondering if this has been discussed much? I've been homebrewing for a number of years, aware of the temperature ranges for each, and how modern malt is modified very well.

I'm thinking about low carb brewing (Brut IPA etc), and was wondering why I don't see more of this? Sure the natural beta amylase will mostly become deactivated during the alpha rest, but then you could just cool down and add exogenous beta enzyme right? This should give a very high extract yield and high fermentability? Hesitant with adding the enzymes in the fermentation out of concern about ruining hop profile for hoppy beers.

Any thoughts on this?

 

[day_trippr]

You're not wrong - exogenous enzymes are obvious game changers versus coaxing "natural" saccharification enzymes to do the job. Once you've opened that jar you can do all kinds of conversion stuff like pounding glucoamylase to bring FG down to 1+zero...

Cheers!

 

[mac_1103]

I don't think it's really a Brut IPA unless you get it fermented dry. As in <1.000. You're probably not getting that without exogenous glucoamylase no matter how you mash. A diastatic yeast might get you close.

 

[doug293cz]

As the title implies, wondering if this has been discussed much? I've been homebrewing for a number of years, aware of the temperature ranges for each, and how modern malt is modified very well.

I'm thinking about low carb brewing (Brut IPA etc), and was wondering why I don't see more of this? Sure the natural beta amylase will mostly become deactivated during the alpha rest, but then you could just cool down and add exogenous beta enzyme right? This should give a very high extract yield and high fermentability? Hesitant with adding the enzymes in the fermentation out of concern about ruining hop profile for hoppy beers.

Any thoughts on this?

What would be the rationale for doing an "alpha rest" before the lower temperature "beta rest"?

I put the rests in quotes, because both enzymes are active at temps down around room temp. If they weren't active at those temps, how would germination and initial growth of the seeds work? All of the enzymes work faster as the temperature increases. Alpha amylase is active in the beta rest temp range. If it weren't for denaturing of the enzymes, we would mash hotter to have things go faster. The "optimal" temp ranges are determined by the point where denaturing starts to speed up to the point where denaturing can start to overtake the the enzyme action, so the "optimal" temperature is below that crossover temp to ensure that the enzymes can complete their work before they are denatured. The beta rest optimal temp is lower than the alpha rest optimal temp because beta amylase starts denaturing at a lower temp than alpha amylase.

Also, adding exogenous beta amylase, after a rest that would denature the native beta, may not actually do anything, as you will have denatured the limit dextrinase which is the enzyme actually responsible for higher fermentability of wort mashed at lower temperatures. Limit dextrinase breaks down the branching bonds in amylopectin, reducing the amount of dextrins in the wort, so that the alpha and beta amylase can create more fermentable sugars.

From the .pdf attached below:

Brew on

 

[day_trippr]

No problemo!

The heck with Brut, we're going Sahara here

 

[doug293cz]

No problemo!

View attachment 817466

The heck with Brut, we're going Sahara here

Who sells that?

Brew on

 

[day_trippr]

Hahahaha! Honest to gawd it was a Google hit to a quick inquiry
Who knows if it's legit. Got bucks you would otherwise light on fire?

https://www.megazyme.com/limit-dextrizyme-tablets
Cheers!

 

[mac_1103]

That's an assay substrate for limit dextrinase, not the enzyme. I assume the glucoamylase is for use as a positive control.

 

[day_trippr]

Aww...I didn't even read the thing but clearly you're right.
Too bad, takes all the fun out of it

But wait!

https://www.creative-enzymes.com/product/limit-dextrinase_13994.html
Cheers!

 

[doug293cz]

No problemo!

View attachment 817466

The heck with Brut, we're going Sahara here

A little interwebs searching leads me to believe that "Limit-Dextrizyme" is a reagent for determining concentrations of limit dextrinase, so is not actually a catalyst for hydrolysis of starch branching bonds. It is also hellishly expensive at 289 Euros for 200 tablets.

Brew on

Edit: beat to the post again.

 

[jujitsudave]

Thanks for the feedback everyone. I think I will read up on limit dextrinase.

The rationale for the approach was based on the recommended temperature ranges for products like Ultra Ferm and Amylo 300. I’ll double check, but I recall that the products state to not go over 140? Presumably this is even further away from the alpha temperature range.

My limited understanding of the various enzymes was alpha breaks up the big stuff into medium stuff, and beta breaks the medium stuff into small stuff. So just trying to get as much efficient as possible, and ensure as high of fermentability as possible. I tried to mash at 140 with Ultra Ferm for 2 hr. FG stalled out at 1.004. Which is super dry, but not what I was hoping for. Also tasted a little watery.

 

[Red over White]

Check out the ascending optimal pH of the 3 major enzymes at work.

A macro lager schedule of doughing-in at 113 & raising to hit your favorite rests doesn't hurt things.

 

[Protos]

You may do that even without adding enzymes. There's so called Hermann Verfahren method in brewing Weissbiers where you mash half of the grist in the a-amylase range and then mash the whole grist in the b-amylase range. I tried that and got a 12% rise in extraction efficiency.

 

[hottpeper13]

The Alpha first ,Beta second is called reverse step mashing in Gordan Strong's book. I do overnite mashes that start at 152* and in 6-8 hrs are at 141*. Kunce's book states Beta as denaturing in around 30 min at 154*,hence the 152* start. The last one was a beer fermented with 2565 and it finished at 1.002, dry enough for me.

 

[mac_1103]

The last one was a beer fermented with 2565 and it finished at 1.002, dry enough for me.

Out of curiosity, where did it start?

 

[hottpeper13]

It started at 1.050 and was a 5 gal starter so i could repitch onto 18 gal of wort for the make up beer in my solara barrel.

 

[Miraculix]

You can just remove a part of the liquid, let's say 50%, after about 15 minutes of beta rest. Do a long alpha rest afterwards with the remainder of the mash, chill it back down to beta rest temperature afterwards and add back the removed part of the liquid.

Us Germans do this for certain wheat beers. You got the best of both worlds without the need for extra enzymes.

 

[jujitsudave]

Thanks everyone, some good ideas to ponder for the next attempt.