Author: Andrew July 28, 2019

Every time I’ve brewed with Munich malt, I’ve had a problem of what seems to be acetaldehyde (or maybe it’s just ‘green’) flavor in the beer. There hasn’t been many, and these have not been brewed consecutively. Brews between these have NOT exhibited the same flavor, and the flavor does fade after time.

Brew 1: British Mild

This was brewed on 9/3/2017 and was supposed to be a partial fresh-hop (Chinook) IPA, propped up with some Chinook pellets. The hop character wasn’t as extreme as an IPA and I ended up using some S-04 mixed with an un-inflated bag of Denny’s Favorite (long story). I noticed the acetaldehyde flavor, as did a judge or two at a competition. I liked the beer, though, and drank the heck out of it.

Brew 2: Dunkelweisen

This was brewed on 12/17/2017. This beer was all over the place, and at one point had a distinct Festbier taste, probably from the aroma hops I shouldn’t have used. I recently (at time of writing) opened an old bottle and it’s way too bitter for a Dunkelweisen.

Between brews 1 and 2, I brewed an IPA. No Munich Malt in that one, and no acetaldehyde-ish flavor.

Brew 3: Bock

This was brewed recently (12/27/2018), and it was a door prize from my homebrew club. It ultimately got over the sweet flavor to end up as a damn good beer that won a gold medal in the Bloatarians Bockfest Competition.

Between brews 2 and 3, I brewed a Flander’s Red (still in the fermenter), a pale ale (had a different off flavor later found to be due to improperly cleaned equipment), a tropical stout (no off-flavor, no Munich Malt), and a pale ale (no off-flavor, no Munich Malt)

Brew 4: Fuck Munich Malt Beer!

The two common threads the above beers have is the same LHBS and Munich Malt. So I decided to test this out with a beer somewhat reminiscent of that British Mild above, but with a little bit more backbone. I purchased the grist from a different LHBS.

Recipe was simple (but not simple to get from BeerSmith on my iPad to WordPress). This is for 5 gallons into the fermenter:
10 lb Maris Otter
1 lb Munich 10
0.5 lb Crystal 60
0.6 oz Magnum @ 60 min
1 oz Fuggle @ 15 min
1 oz Falconers Flight 7Cs @ 5 min
1 pack Wyeast 1318 – London Ale III

I made a change to this brew day – I added some stainless. I bought two pickup tubes – one for the bottom of my kettle and one for the top. The bottom is to get more wort with less tilting. The top is to form a whirlpool during the final 15 minutes when I recirculate through my plate chiller to sanitize it.

Brew day was somewhat frustrating. First, my thermometer disagreed with my PID… and I’m not 100% sure which one was correct. Ordinarily, I’d go with the thermometer, but later this happened…

Then my plate chiller (which is a 🤬🤬 piece of 🤬🤬 🤬🤬🤬🤬 🤬🤬 🤬 🤬🤬 🤬🤬🤬 🤬🤬🤬🤬… and don’t even ask what a ‘🤬🤬🤬’ is!) clogged. Had it not, that new stainless would have had a damn good whirlpool. Given my frustrations with cleaning it (it likes to hide break material and hop material no matter what I do to clean it), I broke down and bought a counter-flow chiller the day after brew day.

There was another issue. I thought about how I’d make a whirlpool, but did not think about how I would get beer into the fermenter. Oops. I’ve bought more stuff from Brewer’s Hardware to fix that, too.

This ended up staying in the fermenter for a while, and during various tastes, I DID pick up on that overly-sweet flavor. Somewhere (I don’t remember if it was a podcast like Experimental Brewing or talking with a friend+brewer or homebrew club buddy), I got the idea that it might be a yeast phenol. I ended up leaving it in the fermenter for an extra week or two. The flavor faded, which makes me think that it is a yeast-based off-flavor. The British Ordinary Bitter that I ultimately kegged was quite tasty after the extra conditioning time.

The appearance is hazy with a copper color with a white head. The aroma is slightly hoppy with some nondescript malt. The flavor is bready and cherry, and is really quite nice, and there is a slight bitterness on the end that has a slight woody quality. It was a bit of a hit at a homebrew club meeting.

Back to that “Fuck Munich Malt” Part…

As is similar with the others, I brewed a few things between brews 3 and this brew – an IPA and a Saison, neither have an off-flavor or Munich Malt, and after this brew, I brewed a milkshake IPA with no off-flavor and no Munich Malt (the flavors are pretty strong in that, so this doesn’t tell us anything!)

So one thing to note is that I *did* taste that off flavor with the malt from the different LHBS – so I feel like it is NOT a problem with either LHBS, it’s a ‘thing’ with Munich Malt. There’s a lot of beers that use Munich Malt that are lagers, and the extended lagering should ultimately drive off the flavor.

Cheers!