Have you ever had a Schwarzbier and thought, "I wish this was a bit more malt-complex?" And have you ever drank a Munich Dunkel and thought, "I kind of wish this had a bit more roast to dry it out?" Well, friend, I have an answer for you: Czech Dark Lager. My first exposure to this style wasn't all that auspicious: it was a skunked-out bottle (yes, even dark beers can skunk, I'm sad to report from personal experience) of a mass-produced version of the style, and it was thoroughly unimpressive. Luckily, over the years I've come across a few genuinely inspiring versions. So, we have an interesting style that is semi-hard to find commercially…sounds like just the kind of beer that we homebrewers should be lining up to make! Add this one to your dark lager rotation, at least once or twice, and I'll be surprised if you don't start finding excuses to brew it.
As previously noted, this beer isn't just a Czech knock-off of a Schwarzbier or Munich Dunkel. Neither is it quite the same as an English Porter, though that might be the closest comparable style. What we have here is definitively a session lager, but one with outsized malt complexity and (in this version of the style) complementary roast character and some spicy hops flavor. ABV can be quite low - we're only going to 4.6% here - but the flavor makes it seem much grander, thanks to some complex base and light character malts. Bitterness is modest - between 20 and 30 IBUs - but is accentuated by the chocolate malts. We also have the same smooth bittering found in most Plzen-inspired beers, thanks to a water adjustment to soften things up. Finally, don't get too distracted by this as a "dark" lager (or a "black beer," as it is sometimes described in the original Czech) - it's dark-ish, but think in terms of dark flavor than dark color.
As with most of the Czech lager recipes you'll run across, this one benefits from using a good floor-malted Pilsner as its base. If you can't get fresh malt, though, you may want to improvise: fresh Maris Otter is better than stale floor-malted Pils, and if that's your best choice you can augment your light-malt complexity with some Vienna or Munich and maybe some Crystal 10L. But assuming you have access to a homebrew shop with good pull-through, you can trust that the fresh floor-malted Pils will give you lots of complexity without the tinkering and trial-and-error: start with six pounds here. To that we'll add one pound each of Victory malt and Caramunich malt, which will really ramp up the rich, toasty flavors in the beer. Last, add three-quarters of a pound of pale chocolate malt: it will impart lots of light coffee and chocolate notes with a hint of burnt husk. If you're really committed to a very dark version - and if you'll be entering this in competition, I might recommend it - you can adjust color with some midnight wheat or Carafa Special III. Otherwise, leave it be; it should end up a nice medium-brown with ruby highlights.
Hopping is pretty easy: two ounces of Saaz, one at 60 minutes or first-wort hopping, and one at 20 minutes remaining. That should give you about 25 IBUs, but if it's a low-alpha-acid percentage harvest year, just adjust your initial addition upwards to get there.
And it's back to the regionally-appropriate Wyeast 2124 Bohemian Pilsner yeast, here. I don't always recommend the regional yeast-of-choice, but sometimes it's just the best call - most of the Czech lagers fall into that category.
As discussed for other Czech lagers, you'll want to use a soft water profile for this beer. For me, it's a simple matter of a 50% dilution with distilled or RO water - your mileage may vary. If you have a water report handy, consult it and calculate how far you can dilute without dropping your calcium below 50ppm. If you don't, then you may have to wing it based on how generally hard your water is. Soft already? Leave it be. Kind of in-between? Cut it by 40-50%. Hard-as-heck well water that won't wash off soap in the shower? Go ahead and dilute by 75%.
With that out of the way, go ahead and mash-in. 152F for 60 minutes is fine here, and lauter/sparge as usual. If you're first-wort hopping, go ahead and add the hops to the kettle as you're running off - the extra few IBUs might be nice!. Then boil, chill, and pitch your yeast, fermenting at 50F initially (for the first 4-5 days), then ramp up your temperature to about 60F until the completion of fermentation. Cold-crash, package, and carbonate to about 2.25 volumes of CO2.
If your fining, hot break/cold break, and cold-crashing have done their job, you should already have a pretty clear beer! Waiting a few weeks in lagering, though, will leave it brilliantly clear with what should be a really pretty reddish jewel tone. We drink with our eyes first, but you should also really enjoy what ends up in your mouth: a low-ABV, complex, lightly roasty and slightly hoppy dark lager.