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You are here: Home --> Forum Home --> Brewing Forum --> Brewing Discussion --> Need Help to Increase Wort Fermentability

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chino_brews
Charter Member
Eden Prairie, MN
301 Posts


I am expecting my wort to be highly un-fermentable if I use a normal infusion mash. I can't change the grain bill.

What can I do to get a more fermentable wort?

Is there a way to increase limit dextrinase activity significantly?

How about a mash schedule like dough-in at 105°F for 10 minutes, increase to 145°F for 45 minutes, and increase to 155°F for 45 minutes?

I'm open to any ideas. Thanks!

3




Posted 34 days ago.

KidMoxie
Charter Member
San Elijo Hills, CA
405 Posts


Gordon Strong recommends 10 min @ 131, 30 min @ 145, and 30 min at 158 for "malty, but attenuated."


2




Posted 34 days ago.

testingapril
Charter Member
Atlanta, GA
595 Posts


More steps and a low initial sacch rest will get you the most fermentability. I have not had a problem getting full conversion at 145F single infusion and that results in a very fermentable wort.


You could also consider adding beano or amylase enzyme in the fermenter.


2




Posted 34 days ago.

chino_brews
Charter Member
Eden Prairie, MN
301 Posts


@KidMoxie: Do you think longer mashing would help?
2




Posted 34 days ago.

chino_brews
Charter Member
Eden Prairie, MN
301 Posts


@testingapril: thanks. You think that would work with a very high proportion of specialty malts?

I'm a little leery of Beano because it is uncontrollable. It's always an arrow in the quiver I guess. Dave Logsdon says that commercially available amylase enzyme contains a high bacterial load by necessity due to the production process, so he disrecommends it for brewing.
2




Posted 34 days ago.

testingapril
Charter Member
Atlanta, GA
595 Posts


I never heard that about amylase. One of the really popular recipes on HBT uses it. I wonder how that works out.


I think I know what this is for.


I would mash for a long time At low temp and just hope that does the job and then you can have beano as a backup option.


2




Posted 34 days ago.

chino_brews
Charter Member
Eden Prairie, MN
301 Posts


So you don't see a benefit to mashing low for a long time, and then stepping up to 155°F for a while at the end to break up any dextrins because -amylase can only get at the non-reducing ends? I don't have a lot of experience with mash schedules beyond single step infusions.
2




Posted 34 days ago.

ingoogni
nl
314 Posts


Can you split off a part of the grain bill, take a part of the Pale or pils malt and make a cold extract (30°C). Mash in at 63°C (30 - 45 min), step to 73°C (20-30 min), ideally cool back to 63°C and add the cold extract. You can add the cold extract at 73°C.

Also make sure mash pH = 5.4, optimum temperature for limit dextrinase in malt is 60 - 63°C (for the pure enzyme it is 50°C)

Edit: literature on limit dextrinase




Posted 34 days ago.
Edited 34 days ago by ingoogni

uberg33k
Charter Member
The Internet
314 Posts


Do a  Herrmann-Verfahren mash schedule.  It's somewhat similar to what ingoogni is describing.  Basically, take 60-70% of your grist and do a long  alpha amylase rest.  You'll have a lot of maltose and alpha-dextrin.  Allow the mash to cool down to under 113F and then add in the rest of the grist.  This allows maltase to be active and break down all the maltose made in the first step into glucose.  Now slowly ramp up to beta amylase rest range and let it sit there until you get a clean iodine test.  You'll be left with a high load of glucose and maltose and just a smallish fraction of dextrins.  I promise you, it will be highly fermentable.



Posted 34 days ago.

rayfound
Charter Member
Riverside, CA
313 Posts


You may want to listen to the BrewStrong episode on mashing recently. Palmer made it sound like low/long isn't ideal because the enzymes are still denaturing at that temp. 

2




Posted 34 days ago.

ercousin
Charter Member
Toronto, Canada
77 Posts


I regularly get down to 1.007 and 1.008 just mashing at 150*F. WLP090 for the win!
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Posted 34 days ago.

CentralCalBrewer
Fresno, CA
89 Posts


>> WLP090 for the win!

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2




Posted 34 days ago.
Edited 34 days ago by CentralCalBrewer

rayfound
Charter Member
Riverside, CA
313 Posts


The biggest impact on FG is the OG, IMO. Obviously 80% AA is  1.014 on a 1.070 wort, vs 1.009 on a 1.045 wort... I mash nearly everything 150-152F, and frankly regardless of yeast used, I almost always end up 75-82% AA. Actually, i have only ever had 2 batches come in under 75% AA. 80% is pretty typical with the yeast and wort I'm using. Obviously higher if I include sugar. 

2




Posted 34 days ago.

testingapril
Charter Member
Atlanta, GA
595 Posts


Most impressive attenuation I've ever had was TYB Dry Belgian Ale. 1.092 to .996 103% AA, which is 85% 'real' attenuation.
2




Posted 34 days ago.

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