Brew day: Nimbostratus Dunkel

There's been a trend in homebrewing lately to make "SMaSH" beers--beers brewed with a Single Malt and a Single Hop. More often than not they're done to showcase a hop varietal, but I like the idea of encouraging simplicity. I can't tell you how many times I've seen new brewers post recipes online that have ten different malts plus flaked oats and candy sugar. I was guilty of some of that myself when I started brewing, but at some point I realized it's better to start simple with a recipe; you can always add specialty grains the next time if something is missing.

As somebody who brews primarily German styles, I've found that 95% of what I want out of a malt profile can be accomplished by using some combination of Pilsner and Munich malts. However, I've never done a beer with just one malt . . . until today. I've been wanting to brew a beer with a double decoction and I figured what better way to showcase just what a decoction can contribute than to use just one malt? With that in mind, today I brewed a Munich Dunkel that was 100% Munich malt. I thought about only using one hop as well but I have a bunch of relatively high-alpha Horizon hops that I use for bittering that wouldn't really be good for a later addition, so I added Hallertau Herbsbrucker to the mix as well. But the end result is a very simple beer that will nonetheless offer a complex malt profile (or so I hope).

I used the double decoction schedule I described a couple months ago in this post. I mashed in around 130°F (adding 3/8 tsp. acid blend to keep my pH down) and ten minutes later pulled my first decoction. I gave it a ten-minute rest at 158°F and then brought it up to boiling for a half hour. I returned the decoction to my mash, which had dropped to 125°F (it was cold today!) but to my surprise the mash only raised to 148°F instead of 158°F. I'm not really sure what happened there but I quickly boiled three quarts of water to bring my temp up.

After adding the boiling water, I gave it ten minutes to stabilize and then pulled my second decoction, which due to the added water ended up thinner than the first. I gave it a ten-minute rest at 168°F and then again boiled for a half hour. I returned the decoction to the mash and, as was the case with the first decoction, I was a little off my target--reaching 164°F instead of 168.

After a 30-minute break (I had to heat my sparge water, since my burner was otherwise occupied with the decoctions) I recirculated for fifteen minutes and then collected 6.4 gallons of wort in just over an hour. I then boiled for ninety minutes, with hop additions at 90 minutes, 60 minutes, and 20 minutes, as well as Irish moss at 15 minutes. I chilled to around 48°F and found that my OG was high (1060) but my yield was low (4.5 gallons--not sure what happened there). As such I diluted with a half-gallon of water to bring my OG to my target of 1054. I aerated and pitched a slurry of lager yeast courtesy of Doug and Tracy at Metropolitan Brewing.

Overall it was a long day (around seven hours if you include clean-up) but I could save about a half hour by using my bucket heater to start heating the sparge water as soon as I start brewing. Plus if I'm brewing lighter beers I don't need to do half-hour decoctions. In the meantime, I can't wait to see what kind of malt character I get out of this beer. Should be great for those dreary days of late winter...