Amylase enzyme

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lemy

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I did a gravity check last night and it has gone down from 12brix to 11brix. currently around 1.022

So, where does it stop?
I am happy to see the gravity drop, but I really didn't want a dry stout. My goal was somewhere around 1.017-1.019...
 
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I did a gravity check last night and it has gone down from 12brix to 11brix. currently around 1.022

So, where does it stop?
I am happy to see the gravity drop, but I really didn't want a dry stout. My goal was somewhere around 1.017-1.019...
The only way to stop it is to kill the yeast. You'll need heat to do that.

It'll keep fermenting to the limit of fermentation, which is about 85% of the OG. For you, that's 1.012.
 
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Can you cite any references for this please?
Alpha amylase is the same enzyme in barley. At mash temperatures, they are slowly denatured, but not before they cleave the big sugars. At room temperature, they work forever, to the extent that AE can. That's it's "limit of fermentation".

I read it on Kai Troester's site. It's also in this big expensive brewing book I have. I'll cut the quote out of there and drop the link here after I get back from the dog park :)
 

MrFancyPlants

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Alternatively, if the gravity goes too low, you could add some lactose in to raise it back up. I bet it'll turn out pretty nice as is.
 

lemy

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Alternatively, if the gravity goes too low, you could add some lactose in to raise it back up. I bet it'll turn out pretty nice as is.
That is true, but I think I will live with the 1.012, which is totally acceptable. I do not want to do any more to this beer than I already have :)
 

lemy

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The only way to stop it is to kill the yeast. You'll need heat to do that.

It'll keep fermenting to the limit of fermentation, which is about 85% of the OG. For you, that's 1.012.
Sulfites would do it too, which is what they do in wine and cider, but 1.012 for a FG is fine with me. I just hope it isn't jet fuel :)

Thanks for the info!
 

doug293cz

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How does the branching limit work? I thought that this stuff had the potential to run away like Beeno so I have never used it post boil.
Starch is made up of amylose and amylopectin. Amylose is a straight chain polymer made of up of lots of glucose molecular units bonded together. Amylopectin is made up of lots of straight chain segments made up of glucose, along with occasional branches. Amylose can be completely converted to fermentable sugars by both alpha and beta amylase. However, the amylase enzymes cannot break the bonds at amylopectin branch points, and in fact cannot even cut off all the glucose molecules near the branch points. So what's left over, after the amylase has done all that it can do, is branched remnants of the amylopectins, with short glucose chains emanating from each of the original branch points. These are known as limit dextrins.

Adding amylase enzyme to the fermenter can finish converting any amylose that was left after the mash, and can convert any dextrins with long glucose chains to limit dextrins, plus maltose & glucose.

There is an enzyme (limit dextrinase) in barley that can break the branching bond in amylopectin, but it is completely denatured before we ever get to normal saccharification temperatures, so plays no role in typical mashes. Beano has something that, like limit detxtrinase, can break the branching bond in the limit dextrins. Thus it can finish converting the dextrins to fermentable sugars, which amylase cannot.

For more information read: www.braukaiser.com/wiki/index.php?title=Starch_Conversion

Brew on :mug:
 

Natdavis777

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For my Cream Ale I used it in the mash (I believe it said that on the bottle) and it still finishes around 1.010. Should I be using this rather in the fermentor days before packaging instead?
 

Schlenkerla

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For my Cream Ale I used it in the mash (I believe it said that on the bottle) and it still finishes around 1.010. Should I be using this rather in the fermentor days before packaging instead?
I'm not sure a cream ale should be dry. If you want it dryer mash at 147F and add AE in the secondary.
 
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For my Cream Ale I used it in the mash (I believe it said that on the bottle) and it still finishes around 1.010. Should I be using this rather in the fermentor days before packaging instead?
It probably wouldn't do much for you in the mash. The malting process ensures that your barley contains loads of these enzymes. AE in the mash could be useful if you had a mash with poor enzyme content, for example not much barley and a lot of rice and corn etc, where you might need to add additional enzymes. AE would work for that.

Note that when you boil, the AE is denatured and becomes useless.

It might not help much in the fermentor if you already got good attenuation. Just put a teaspoon in the fermentor and see what happens. Might get a couple of points more.
 
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