Issues with my beer's attenuation

[nachov]

I took a reading today: S.G. 1.025
It hasn't change for 3 days, so that's gonna be my F.G.
It's cold-conditioning now.

That beer might eventually come out quite tasty.
I don't actually mind a high residual sweetness.

BTW, I used a light DME.

 

[nachov]

Hi folks,

I've just found out about a thing called the diastatic power

I used 50% bohemian pilsner malt which might have 60 lintner;
and 50% Munich Amber Malt (not the darkest one) which might have 60-70 lintner.

Actually, I used adjuncts as well but in very small proportion.
So, I believe the diastic power should have been enough (well over 50)

I'm wondering if malts can lose diastatic power during storage?
I store my grain in sealed plastic food container, it's not air vacuumed
but it try to keep the air out as much as possible.

It's been kept over 80F for around 4 months (I used to live in a warm area).
Could my storage conditions have affected the diastatic power?

BTW, can somebody explain to me how a weak diastatic power can affect the beer?
For instance, with weak diastatic power I don't understand how come a brewer can reach his desired S.G. (with decent efficiency) and end up with a low F.G.

With weak diastatic power I would expect a brewer to hit poor efficiency.
But apparently, you could hit decent efficiency but you would end up with no enough fermentable sugars.

I guess that might be related to the extent which the enzymes would break down the sugar;
but it's not clear to me.

Thank you for shedding some light.
Cheers.

 

[40watt]

I'm afraid I don't know how storage would affect DP.

You are right about one thing for sure. Diastatic Power is all about a grains ability to produce enzymes to convert starch to sugar.

Grains with a high DP (hence the use as base grains)

Pilsner
pale malt
2row
6row (highest DP)

Those grains can convert themselves as well as grains in a mash with no DP.

Grains that con convert, but the DP is lower and not advisable for 100% of base grains.

Vienna, Munich, etc.

Your special and roasted malts have little or no DP left. To the extent they can be converted, they must rely on the DP of your base grain.

Some adjuncts like corn or rice have no diastolic power. They will not convert without the enzymes from the base grain.

 

[40watt]

I regards to your batch. 50/50 pilsner and Munich should convert just fine.


What was the mash schedule?

 

[40watt]

Oh yeah.


Yeah can get good efficiency with a low DP. You have broken down the starches to sugars. The problem would be that the sugars are still too long of a chain to be fermented by brewers yeast. Hence the high final gravity.

One thing you could do is just do a longer mash. Give the enzymes that are present more time to cleave the sugars into smaller chains.

 

[nachov]

I did a single infusion mash at 150F for 60 min.

Yeah can get good efficiency with a low DP.
You have broken down the starches to sugars.
The problem would be that the sugars are still too long of a chain to be fermented by brewers yeast.
Hence the high final gravity.

Thank you! I got it now.
Now, I understand the use for an iodine test.

 

[40watt]

That mash should work fine.
I would probably mash 75 to 90 minutes, but I have been obsessed with attenuation for a while.

I think more than losing your DP from poor or long term storage of grain, the problem would be a stale character. That is 100% my opinion. No science.