I don't have a whole lot of experience (I've been brewing all-grain for less than a year) but I've found that every beer I've made with Munich or Vienna malt (usually 2 - 4 pounds in a 6-gallon batch) has a sort of pervading dullness about it. I've been extremely pleased with most of the beers I've made, but the ones with Munich or Vienna have simply left me unimpressed.
Has anyone else experienced this?
Possibly what's happening is that the increased maltiness from the Munich and Vienna is offsetting the hops and making the beer seem less balanced. Yeah, it's a long shot, but based on what you're tasting could it be something like that?
How long are you mashing? If, for example, you mash for 60 minutes using American 2-Row Pale as a base and for the same amount of time with Munich, you might not be converting all of the sugars you need to.
Why? Enzymes. To put it simply, Munich malt (and to a lesser extent, Vienna) has lower diastatic power than American 2-Row. It will take longer to convert starch into fermentable sugars.
Weyermann's Munich II has a diastatic power of 25 Lintner. Briess 2-Row Pale has a diastatic power of 85 Lintner (Weyermann Vienna has 50).
I've seen multiple sources--though admittedly they might all come from the same origin--that say you should try to aim for about 25-35 °L per pound of grain in your mash. My results tend to show that you can completely ignore any grain that doesn't need to be mashed (e.g. crystal, chocolate, etc.) when calculating.
The quick way to calculate this:
To use an example, I have a beer I'm brewing tomorrow that uses Munich II as a base and includes Aromatic, which must be mashed. All my other ingredients don't require mashing, so I'm ignoring them for my calculation.
That's on the low end. Sometimes that means I'll add a little something with a lot of diastatic power (such as Briess 6-Row Brewers Malt, which has a diastatic power of 160 °L). What I usually do, though, is extend my mash time by 30-60 minutes. That usually serves me well and it doesn't alter the flavor of my beer.
Another thing I've been wondering is if I need to do these beers as proper lagers. I've been doing them as pseudo-lagers (usually Nottingham yeast at as-low-as-I-can-easily-get temperatures). This is working great (as far as my taste buds are concerned) with the pilsners/light lagers I've been doing, but maybe I just can't get away with this slap-dash approach with my beers with munich and vienna?
