High Finishing Gravities

[turboturist]

Hey All

I use malted gluten free grains for the well known suppliers. I mash at 158-163 for 90, let it cool to 152 and add the liquid enzymes wait 30-40min and then run the iodine test to make sure starch conversion has happened.

I'm always within a point or two of calculated OG, but my beers seem to always finish 10-15 points high of calculated FG.

Example I did a red ale recently and calc OG was 1.064 and measured came in at 1.065. Calc FG was 1.017 but it came in at 1.031.

Anyone else having this issue, or have some tricks they can share to rectify?

Thanks, Wes.

 

[thehaze]

Isn't 158-163F too much?

Is gluten free brewing different in that aspect?

I would not go higher than 154-155F and that is for those big NEIPAs with lots of hops and maybe a bit of sugar.

If you want more attenuation, you need to mash at 149-150F, use a more attenuating yeast or simplify the grain bill, as more specialty malts will get you more unfermentables, hence higher FG.

 

[turboturist]

Temps are different with the gluten free grains, grouse the one supplier recommends 163, and some guys go up to cereal mesh temps in the mid 170's with GF grains.

 

[Legume]

You might extend your 152 degree rest.
I dont know which enzymes you are using or their concentration...but i usually do a 90 minute sac rest to get to a FG of 1.010 to 1.012. If i want a FG closer to 1.014 I do a 60 minute rest.
My process is diffrent from yours and I dont expect these mash times to result in identical FG numbers, but extending that 152 rest will get you closer to where you want to be.

 

[turboturist]

Thanks Legume, I use the liquid Termamyl from brewcraft. Typically 10-12ml per 5gal.

You mentioned using AMG-300 in the past, would that help? I'm having a hard time finding it. Any replacements you know of our recommend?

 

[Legume]

The Termamyl is your problem.
Termamyl is a fantastic product, but it only has alpha amylase activity (not beta amylase).
It is very good at cutting long starch chains into shorter (still not frementable) dextrine chains. It does a very poor job of making maltose and glucose (fermentable sugars).

Try mashing with Termamyl at 175 F for 90 min.
Then lower the temp to 150, add AMG300 and mash for 30 min at 150.

AMG is a super agressive beta amylase, and will result in low final gravity.
You can experiment with how much AMG300 to use, and how long to hold that rest to dial in your FG.

 

[Legume]

SEBamyl L is a much better product that AMG300 for making beer (this is what i use)...but it is even harder to find.

 

[rjmaillie]

+1 on what Legume says above.

An alternative to AMG 300 that i use is Diatase Enzyme from EC Kraus. It has both Alpha and Beta Amylase and I find it works well without being too aggressive.

So Ill gelatinize with Termamyl and drop down to normal mash temps as above, then add the Diatase (1/2 tsp for a three gallon batch) and mash 1 hour. I get 80% attenuation on average with that process, yeast dependent of course.

 

[Lefou]

Try using a more attenuative yeast - like a Belgian or French saison strain that can work at warmer fermentation temperatures. Belle saison dry yeast or liquid Wyeast 3711.....
If your conversion is efficient with few dextrins left over in the mash the more attenuative yeasts will help solve your issue, but be aware, these yeast strains can yield a dry result.

 

[turboturist]

Ok perfect, thanks for the help!! Time to do some more experimenting going forward.

 

[turboturist]

Hey guys, I found that I have access to this here in Canada. It's my understanding that this has endo and exo amylase. But want to confirm, thoughts?

Amylo[emoji769] 300 can hydrolyse sequentially both exo alpha 1,4 and alpha 1,6 glycosidic linkages and can therefore be used to degrade starch polymers and maltose to glucose.