Beautiful in the mug, rich on the palate, yet—when properly brewed—so easy to drink in quantity, Czech dark lager is a niche even in its home country. Writing from Prague, Evan Rail talks to the pros to understand the elements and methods that go into a great one.

Evan Rail Aug 22, 2022 - 10 min read

It’s easy to overlook tmavé pivo, the Czech Republic’s other beer style. Long overshadowed by the world-famous pale lagers—or pilsners—that originated in the Czech city of Pilsen, the dark and rich tmavé pivo is obscure both literally and figuratively—a relative rarity that accounts for less than 3.5 percent of total Czech beer production today.

Yet, especially as craft brewers continue their love affair with lager in all its forms, the seldom-seen, not-quite-black lager with the strange name is starting to earn more fans outside its homeland.

So, what is it exactly?

Literally, tmavé pivo just means “dark beer” in Czech. Stylistically, however, it’s much more specific: For Czech brewers, tmavé pivo is a specific type of dark lager that resembles the classic Munich dunkel that first inspired it, though the Czech interpretation has a noticeably richer body. Unlike the three malts you often see in the German original, tmavé pivo is made from four, five, or even more types of malt, including caramel and dark roasted malt. And although tmavé pivo can come in any strength, brewers such as Štěpán Kříž at the Czech Republic’s Pivovar Hostomice tend to shy away from low-gravity versions.

“I think tmavé pivo works best when it’s brewed at 13°P and above,” he says, referring to the Plato-scale equivalent of OG 1.052. “Weak tmavé pivo is weird. For me, the wateriness of 10°P beer just doesn’t go together with the fullness of the dark malts.”

The most famous version has to be the one from Prague’s U Fleků, a brewery founded in 1499 that pretty much brews only Flekovské pivo, its celebrated 13°P dark lager. (In recent years, U Fleků also has brewed a pale lager for September 28, which local beer lovers celebrate as the “Day of Czech Beer”—an exception that proves the rule.)

For Kříž, the appeal of U Fleků’s style-defining dark lager is its extreme drinkability, or pitelnost, a word that Czech brewers often use when describing their pale lagers. “What we want is for tmavé pivo to be just as drinkable as pale lager,” he says. “It can’t be too heavy or too flavorful, so that you only drink one and then don’t want to have another.”

People throw “legend” around too often nowadays, but the word fits perfectly on Ivan Chramosil, who worked as the brewmaster at U Fleků for 45 years. Now retired with the title of “brewer emeritus” at his old haunt, Chramosil serves as a beer judge in international competitions and works as a consultant for a number of Czech breweries. In his eyes, the drinkability of a great tmavé pivo depends on its limited sweetness.

“Some people make tmavé pivo really sweet, but it tastes best to me when it is just slightly sweet, with a pleasant, very light caramel flavor,” he says.

Czech brewers, he says, generally make tmavé pivo using pilsner as their base malt, which usually accounts for about 50 percent of the total. The remainder will usually be Munich malt—either light or dark—followed by a smaller share of caramel malt and just a touch of dark roasted malt. Some brewers, he notes, might also include a portion of an aromatic malt such as Weyermann CaraAroma.

“It all depends on your setup, your brewhouse, and the kind of taste you like,” Chramosil says. At Pivovar Hostomice, Kříž brews his tmavé pivo to 14°P (OG 1.056). He uses a classic four-malt combination, but in slightly atypical proportions.

“I personally like to use more than 50 percent of the dark malts,” he says. “Only about 40 percent is pilsner malt. I like to use standard pilsner and the very lightest Munich malt available. But for the caramel malt and the dark roast malt, I want the darkest versions available and in the smallest amounts possible.” That helps him avoid getting too much caramel flavor in the beer, he says.

Just in terms of the malt bill, variations on tmavé pivo are pretty much endless. The beloved, but now defunct, Pivovar Kout na Šumavě used the same four malts as Hostomice for its tmavé pivo, similarly brewing its version to 14°P. But Kout na Šumavě’s was made with 77 percent pilsner malt, 10 percent Munich, and 10 percent Caramunich, with 3 percent Carafa—an oversize portion of the latter, by Czech standards.

Chramosil says many brewers use Caramunich II, while Kříž prefers Caramunich III. As Chramosil says, a lot depends on the specific equipment where the beer is being brewed, and there’s plenty of room for experimentation and variation in the grain bill.

What doesn’t really vary is the process. Tmavé pivo is a Czech beer, and just like a classic Czech pale lager, it should be brewed with a traditional decoction mash.

At Cohesion Brewing in Denver, brewer and cofounder Eric Larkin specializes in Czech styles—including Cohesion Tmavé, a 14°P dark lager. For Larkin, decoction is an essential part of tmavé pivo’s flavor profile.

“Decoction mashing really gives the depth of that malt flavor,” he says. “There’s an irreplaceable quality to decoction mashing. You can get something that may represent those flavors, but it doesn’t come off as full, as rich, as deep of a grain character without decoction.”

While pale lagers sometimes get three decoctions, the process for tmavé pivo is almost always a double decoction in the Czech lands. “I do two decoctions,” Kříž says. “I think three decoctions for tmavé pivo is unnecessary.”

However, there is a catch.

“You don’t put the darkest malt, the Carafa, in the mash, and the Carafa doesn’t go through decoction,” Chramosil says. “You only add it at the sparge. That’s an old brewer’s trick.”

As such, the dark-roasted malt is pretty much only there to add color. A good tmavé doesn’t really have any roasty notes—and it’s definitely not astringent.

“If you include the dark roasted malt in the decoction, it can make the beer too bitter,” Chramosil says.

Other Czech brewers note that tmavé pivo means “dark beer,” not “black hole.” The color of an authentic tmavé pivo requires a light touch with dark malt.

“My goal with ours is to get the color so that at the edge of the glass it’s more like a dark red, starting to turn to dark brown, while in the middle of the Tübinger glass, it’s closer to straight black,” Larkin says, referring to a dimpled mug commonly used for Czech lager. “Ours is devoid of roast character—we’re trying to go for more of a chocolate as opposed to a coffee flavor.”

After all the effort of creating that rich, malty complexity with the decoction mash, it’s important not to over-attenuate your wort, Larkin says.

“Using a Czech lager yeast is vitally important,” he says. “A German lager yeast will dry it out enough that you won’t get that sweetness and richness that I normally get from Czech dark lagers.”

Equally important, Kříž says, is to keep those malty flavors in balance.

“There has to be bitterness as well—you can’t make tmavé pivo without bitterness,” Kříž says. “The fullness of the dark malts has to be balanced with hops.”

While Czech brewers certainly love their native Saaz, that hop is not ideal for the bittering additions of tmavé pivo because of its low alpha-acid levels. “It’s really a waste to use Saaz for tmavé pivo, other than in the final addition,” Kříž says.

Instead, Czech brewers generally use a higher-alpha local hop such as Sládek, Vital, or Premiant for bittering. They don’t skimp, either: Hostomice’s 14°P Fabián tmavé pivo clocks the same amount of bitterness as a top-shelf 12°P světlý ležák, or pale lager, with about 40 IBUs. The right amount for any beer is, of course, up to the brewer, and it very much depends on the beer’s strength and relative sweetness.

“When it comes to how much bitterness, what’s important is [whether] the beer is weak or strong,” Kříž says. “The stronger it is, the more bitterness you need to balance the fullness of the beer’s body.”

After the bittering additions, a healthy dose of traditional Saaz works for a touch of aroma, with that addition usually going in about 15 minutes before the end of the boil.

“That’s the one thing I would tell homebrewers: Don’t be afraid to make it hoppy,” Kříž says. “Add the hops.”

Decoction is not an obsolete brewing technique. It’s one that can take you to other (richer) destinations… even a few you might not expect.

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