less fermentable wort issue?

Any reason why this recipe would create a less fermentable wort? Kind of a dumb question but I am kind of stumped. After 10 days my gravity is at 1.019 which is significantly higher than any beers I have fermented with K97. All signals pointed to a healthy fermentation. I roused the yeast yesterday and warmed up the fermenter which seems to have had little effect but I have not take another reading.

81.7% munich 9L
9.1% flaked oats
4.6% carafa special I
4.6% light unsulphured molasses

mashed @ 153F for 60 min

73.5% brewhouse efficiency

1.053

pitched one packet of K97

I have not conducted a fast ferment test yet…

Nothing obvious

Infection? Have you tasted a sample?

Munich II (I’m assuming 9L Munich is Munich II) is capable of self-converting but tends to result in a dextrinous wort if it is the only base malt due to low enzymatic activity.  Have you brewed this recipe before?

That would probably explain it and is something I didn’t even consider when designing the recipe. I just wanted something very malty…
“mashes with high diastatic power (Pilsner, Pale) will produce more fermentable worts since they contain a lager amount of beta-amylase which can produce more maltose compared to mashes with lower diastatic power (Munich or large amounts of unmalted grains) assuming the same saccrification rest temperature.”

Yes schill designates their 9L as Munich Dark I believe. The first version of this recipe used Munich Light (6L) and I believe my results were worse however that one did not include molasses. I also remember something about a possible yeast issue from repitching a dry yeast slurry which apparently is not recommended. I will have to go back and take a look at the batch.

It was a bit tangy but I believe that was due to a lot of yeast in suspension. That taste has worried me before.

Just a couple more questions.

Looks like my AA is about 64% right now. For those dunkel brewers that use a majority of Munich malt, do you experience less attenuation than normal? Should I have used a couple of pounds of pilsner malt? Would a multi step mash help?

Any recommendations on a good book that explains how different mashing concepts, different base malts, mash temps, etc affect wort fermentability and such?

This is a topic that I obviously have not researched much as I use a lot of pilsner malt and never experience this problem to this extent. I will probably add a bit of brown sugar to boost the ABV a bit more to my liking…

I average 77-84% AA depending on beer. Everything is step mashed.

https://www.vlb-berlin.org/en/technology-brewing-and-malting

Nope.  My all Munich beers attenuate just like any other.

Thanks for your help.

So just to be clear, there is nothing to: “mashes with high diastatic power (Pilsner, Pale) will produce more fermentable worts since they contain a lager amount of beta-amylase which can produce more maltose compared to mashes with lower diastatic power (Munich or large amounts of unmalted grains) assuming the same saccrification rest temperature.”

That’s a huge generalization.  It depends on the particular Munich you use.  I mainly use Great Western 10L or Best 10L Munich and I’ve had no issues with either.

Got ya. Thanks!

You need to learn to read malt analysis sheets, they are your sight glass into the answers… for instance, the Munich I have in my inventory is just as modified as the pilsner.

I’d be a little concerned with Munich that there’s fewer enzymes available so they might not do the job quite as fast as other base malts.  So it may be a mash time thing.  I usually mash for only 40 minutes, but if using Munich as the sole base malt I would mash for at least 60 minutes, which is just what you did.  But I know 75-90 would have helped even more.  Right or wrong, I’m hereby taking mental notes for future personal use…

And maybe it’s just that much different between all the different maltster brands, and even from batch to batch.  Maybe some folks are just getting lucky too.

Kai found much less attenuation when using Best Dark Munich in comparison to Weyermann Pilsner and Munich I when conducting single infusion mashes. As Denny noted, it very well be related to the maltster and the type of munich malt

Thanks

I have found no difference between Best pils and Best dark Munich.

I said kai found a difference when compairing Weyermann Pilsner, Munich I, and Best Dark Munich…

Page 19. Maybe I am misinterpreting his results…

I didn’t use Best but it just signifies what I might be seeing…

Other than cost savings, this is the primary reason I buy base grains by the sack.

Yep, I realized that.  Just giving another comparison.  I get great attenuation with Best pils and the same with Best dark Munich.