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Czech Lager: The Art of the Addictive

Whether you want to brew a more convincing Czech-style lager, or you simply want to borrow a few tricks to shape the kind of beer that seems impossible to stop drinking, here are some elements to consider.

Joe Stange Oct 30, 2023 - 28 min read

Czech Lager: The Art of the Addictive Primary Image

Photos: Jamie Bogner

As smaller breweries across North America show greater interest in a variety of lagers, we often look to the Czechs for inspiration. Yet Czech lager is an infinitely rich subject, and zooming in on any facet only reveals finer details and lessons yet to be learned.

So, let’s begin by saying there is more to Czech lager than throwing in some Saaz and pitching a yeast strain labeled as “Bohemian.” And, after further study, if Czech lager begins to look like an annoyingly intricate puzzle—or a house of cards where all the pieces need to fit together just so—there’s a reason why: That’s how it evolved, as brewers there continue striving to outdo each other in making the kinds of beers that the locals want to drink in serious quantity.

While American craft brewers keep trying to pack more and more character into their beers, the Czechs never stopped trying to brew something that people just want to drink more.

If your quest is to brew a distinctive lager, you can pick and choose the pieces that serve you best. However, if a more authentic Czech character is the goal, it’s difficult to leave out any of these pieces without ending up in another place.

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Decoction: You Can and You Should

It’s naive to think that Czech brewers adhere to decoction like religion because they’re just stuck in their ways. Many also experiment from time to time with infusion mashing—but they stick with decoction for what it adds to the beer. You can make great lager with an infusion mash—that should be obvious by now—but decoction is a critical piece of what makes Czech lager what it is.

“If I could take only one thing that makes a lager a lager,” says Adam Brož, brewmaster at Budvar, “it’s decoction.”

He views the character that you get from decoction mashing as inseparable from how lager is supposed to taste. “The beer is richer in flavor and color,” he says. “You tune up automatically, by nature, the combination of fermentable and unfermentable compounds. … You really tune up the flavor in a natural way.”

To get an idea of how a typical Czech lager decoction might go, here’s a simplified version of the program at Budvar: Mash in low, at 100°F (38°C), then raise it to 122°F (50°C). Separate about a third of the mash and take it through 20-minute rests at 149°F (65°C) and 167°F (75°C) before bringing it to boil for 20 minutes. Then reunite the decoction with the rest of the mash, mix thoroughly—and do it all over again. Brož says the whole mash process at Budvar takes about four hours.

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Many brewers have a simple view of decoction mashing—either it makes no difference, it’s unnecessary, or maybe it only adds some malty flavors. However, when Czech and German brewers talk about decoction, they talk about more than a richer malt flavor—they also talk about better foam stability, higher mash efficiency, more body, and higher attenuation.

Those last two may seem counterintuitive—higher attenuation, yet more body?—but for the Czechs, that’s an important combination. The beer should be satisfying yet digestible—when your mug is empty, it’s a moment of great sadness and longing. And then there’s only one thing left to do.

“The drinkability with decoction is much higher than with infusion,” says Lukáš Tomsa at Dva Kohouti, a popular brewery and taproom in Prague’s Karlín neighborhood. “We focus here on drinkability. A beer needs to be drinkable,” so that the drinker wants only “more and more.”

At highly respected Únětický Pivovar, north of Prague, their classic double decoction is part of their over-arching focus on attenuation for a finish that leaves you wanting more. “All of our beers are dry beers—very dry beers,” says Štěpán Tkadlec, the brewery’s co-owner and director. “It’s important to us.”

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While most Czech pale lagers get two decoctions, the famous Pilsner Urquell sticks with its unusual triple decoction. Retired brewmaster Václav Berka—who now revels in the role as an ambassador for the brand—says that among other benefits, this process provides additional body and residual sweetness for a beer that’s only 4.4 percent ABV. Their direct-heated copper kettles also ensure caramelization for added flavor. “It’s the highest drinkability, ever,” Berka says. “It’s our responsibility to continue this drinkability of pilsner beer.”

Yet another reason for decoction: consistency. Brewers love to talk about how pale lager is a “naked” beer that reveals its foibles. When you’re using relatively subtle hops and only lightly kilned pilsner malt, natural changes in the crop can change your beer—and decoction goes a long way toward ironing out that variation.

“The decoction could smooth the differences of the different crops,” says Brož at Budvar. “It’s amazing that it still works this way today. … The process can buffer the variances [that] are coming from nature.”

Budvar no longer malts its own barley, but Pilsner Urquell does. Variations in the crop may lead to slight tweaks in malting or in mash rests, but decoction is a powerful equalizer. “The biggest role of brewers,” Berka says, “is to produce the beer so that the consumer can’t recognize which crop is used in the beer.”

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Finally, when it comes to decoction, many Czech brewers want you to know this: You can do it.

Granted, some brewhouse setups make it virtually impossible to do a proper decoction mash the Czech way. However, you don’t need a brewhouse designed for decoction to give it a try—and some Czech brewers are managing just fine with modified two-vessel systems. Some investment in modifications may be wise—such as low-shear pumps for moving hot mash around. But there are also shortcuts, such as the Schmitz method or pseudo-decoctions, that can give you an idea of whether you’ll like the results. (For much more on this topic, see Why Decoction Matters and Decoction Shortcuts.)

Perhaps the worst reason to avoid decoction is that it sounds like a lot of work.

“Don’t be lazy!” Berka says. “You can try to make a [decoction] mash. … I trust you will be absolutely successful.”

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“I know it’s not the technically easiest way,” says Brož. “Sometimes it’s not possible with the equipment. But if you’re trying to brew a lager, try to brew a decoction. Don’t give up!”

Clockwise from far left: Germinating malt in the Pilsner Urquell malthouse; Únětický Pivovar malt from Malthouse Kounice; pallets of Sladovny Soufflet malt at the Břevnov Monastery Brewery.

Czech Malt Matters

When decoction skeptics say “you don’t need to” because malt today is highly modified, they’re not wrong—most modern malt, especially outside continental Europe, is less than ideal for decoction mashing. You can decoct it, just as you can do an infusion mash with floor-malted pilsner—and you can make good beer with those worts. But we’d be talking about different worts and therefore different beers.

Proper Czech lager comes from decoction, from malt that’s made for it, and from barley that’s grown to be that malt.

In the large, modern malthouse on its sprawling grounds in Plzeň, Pilsner Urquell malts its own barley to an intentionally low degree of modification, carefully watching the specs. “Why do we do it? Simple answer,” Berka says. “Because we have a very intensive process with the three decoctions in the brewhouse.”

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When brewers elsewhere think of Czech malt, they often think of old-fashioned floor maltings—and long may they survive. Yet they survive as a niche; only about 4 percent of Czech malt today is still floor-malted, according to a maltster at Pivovar Ferdinand. There are still about 14 floor maltings in Czechia, but they’re all small. Many, like Ferdinand’s, are attached to breweries. (Notably, about one-third of the floor malt that Ferdinand produces goes to Bamberg to be sold as Weyermann Floor-Malted Bohemian Pilsner.)

At Únětický, they get the malt for their celebrated pale lagers from a traditional malthouse in Kounice. “From our point of view, it’s the best malt you can get in the Czech Republic,” says Jan Fišera, the brewery’s sales manager. “It’s not cheap, but it’s very good.”

In Prague, the Břevnov Monastery Brewery gets its malt from the Sladovny Soufflet maltings in nearby Nymburk, but it’s not floor-malted. Břevnov brewmaster Aleš Potěšil says the brewery used to get floor-malted barley, but they found it too inconsistent. Meanwhile, next door to the large Soufflet facility is the Nymburk Brewery, which produces the Postřižinské beers. Like Ferdinand, this brewery has its own floor maltings—but even its own lager’s grist is half floor-malted, half Soufflet.

One takeaway: As cool as floor malting is, you don’t need it to brew a great Czech lager. Even the large-scale Czech producers make malt suitable for decoction—because that’s what Czech brewers are going to do with it anyway. Czech malt and decoction are inextricably linked.

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Another tidbit: It’s common (but not universal) for Czech brewers to include a small portion of pale caramel malt in their grist—perhaps 5 percent—just to give a slight nudge to that body and residual sweetness without losing the dry finish.

Ultimately, it shouldn’t be shocking that Czech malt is important to authentic Czech lager. At Dva Kohouti, Tomsa faces a mirror image of the challenge faced by American brewers: “When I make a West Coast IPA from pale Czech malt, it never achieves such a dryness as with American malts,” he says. “So, it works the other way around as well.”

From left: Wooden aging tanks in the Pilsner Urquell cellar still ferment beer served on the brewery tour; open fermentors at Únětický Pivovar.

Saaz Reigns Supreme—But There Is More to Czech Hops than Saaz

There are 25 hop varieties that Czech growers can plant, but 80 percent of what they grow is Saaz. Despite a disastrous harvest in 2022 and concerns about its long-term sustainability, Saaz remains the country’s signature hop.

“Saaz aroma, that’s the standard of hop aroma,” says Zdeněk Rosa, chairman of Bohemia Hop, a trading company owned by a cooperative that includes most Czech hop growers. “There’s always this close connection between the Saaz variety and pilsner.”

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Pilsner Urquell relies solely on Saaz hops—and plenty of them—for its 40 IBUs. “To get proper bitterness, it’s necessary to use a lot,” Berka says. “And it’s not cheap. But quality is not cheap.” That bitterness also contributes to a dry finish when you drink the beer, Berka says, “and because your brain is clever, it begins solving this problem.”

Budvar also uses exclusively Saaz—and only whole cones, pressed into large “pucks” but not pelletized. “I’m sure in the future I will insist on it,” Brož says, “because it really is a pillar of the brewery.” They’ve tested pellets, but “the whole cones are always richer in taste in the final beer.”

When hops are pelletized, some plant material that’s rich in polyphenols is ejected as waste—yet those compounds are useful to pale lagers, and they have a role in flavor and stability. “If you want to deliver the whole dose of the very useful compounds in hops, cones are the only way to deliver that,” Brož says.

Three hop additions are typical, but it’s also common for Czech brewers to add first-wort hops and/or an aroma burst at whirlpool—as Břevnov does with its flagship Benedict 12° pale lager.

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When it comes to relying only on Saaz, Budvar and Pilsner Urquell are two (large) exceptions. Anecdotally, most Czech brewers use higher-alpha Czech varieties earlier in the boil before a late Saaz addition for aroma. At Únětický, for example, they use Agnus then Sládek before finishing with plenty of Saaz. That’s a popular combination: Agnus, Sládek, then Saaz. At Ferdinand, however, they prefer Vital, Premiant, then Saaz.

When Czech brewers use Agnus, they almost exclusively use it for bittering—but Lenka Straková, brewmaster at Pilsner Urquell’s experimental brewery, Pivovar Proud, says she also enjoys using it for aroma. For what it’s worth: When we rubbed some cones at Bohemia Hop, we found Agnus to be a real treat—not only spicy and herbal but also punchy and citrus-forward, splitting the difference between Žatec and the Pacific Northwest.

Agnus also is the secret weapon in the new Budvar 33, as in 33 IBUs, a bitterer version of the classic Budvar (22 IBUs). “We needed some hops that bring the bitterness but [don’t] break the drinkability,” Brož says. That beer also is lagered a mere 50 days, rather than Budvar’s usual 90, so those hops don’t lose their zip.

From left: The coolship at U Fleků is just for cooling, not spontaneous innoculation; the manhole covers in Žatec proclaim it “city of hops”

Diacetyl Is an Integral Element of Czech Lager … Except When It Isn’t.

As a learned brewer who’s learned about brewing in whatever way you’ve learned about it, you’re fully entitled to a strong opinion about diacetyl.

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Here’s the thing: You might as well rage against the háček as rage against diacetyl in Czech lager. It’s just part of the deal—and most Czech brewers will tell you it’s supposed to be there and that their lagers wouldn’t be the same without it.

“We leave in our beer a little bit of diacetyl,” says Berka at Pilsner Urquell, “because we think it influences the drinkability.”

As an organic compound that occurs naturally in beer, diacetyl isn’t an ingredient and can’t be easily adjusted. At low levels, it can add to a sense of richness and body. At higher levels, we’re talking butter bombs. Complicating the issue is that drinkers’ thresholds for detecting it are all over the spectrum. Most Czech drinkers, plainly, either can’t detect it or simply don’t mind.

Given enough time—or a bit of warmth to speed things along—yeast will clean up diacetyl. However, Czech brewers like their fermentations cold, and diacetyl rests are not part of the program.

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At Pilsner Urquell, Berka says, the famous sandstone cellars are 41–43°F (5–6°C), so that’s where fermentation starts upstairs too, in the big, non-pressurized (i.e., “open”) cylindroconicals, before it’s allowed to rise somewhat.

(Incidentally, spunding toward the end of fermentation to get some natural carbonation is just a given. While some Czech brewers still do traditional open fermentation in wide, shallow vats, many others have moved to stainless—but even those are left “open” and unpressurized.)

At Břevnov, they ferment at 46°F (8°C) for about 10 days before capping the tank for natural carbonation, then crashing to 36°F (2°C). In their Benedict, the diacetyl is there if you look for it, but it doesn’t overwhelm the profile. “A lower percentage of diacetyl isn’t a big problem,” says Potěšil at Břevnov. It adds to the sense of body, he says, and “we don’t like beer without body.”

In Budvar, meanwhile—a beer whose profile lands somewhere between a typical Czech pale lager and a clean Bavarian helles—there is no detectable diacetyl. Brož says they pitch yeast at 45°F (7°C), and the fermentation goes no higher than 52°F (11°C) over 11 or 12 days. Yet the luxurious 90-day lagering offers plenty of time for the yeast to finish cleaning up. “In the case of Budvar, there really is no diacetyl,” Brož says, “because you have enough time to get rid of the diacetyl in a natural way.”

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Dialing in your fermentation to produce a Czech-like touch of diacetyl without going overboard would not be easy. The simpler approach is to do the diacetyl rest and get rid of it.

At Pivovar Proud, Straková is working for Pilsner Urquell, whose famous flagship has a touch of diacetyl that is an important part of its profile. However, she prefers to avoid it altogether in Proud’s own lagers. “A really light amount of diacetyl in the beer can work for you,” she says. “But it’s really hard to make that work for you. … So, for me, it’s safer to have no diacetyl and just balance the beer without it.”

One Czech brewery comfortable with diacetyl is Únětický. It can be relatively pronounced in the filtered (Filtrované) version of its 10° pale lager. However, its core 10° and 12° lagers are unfiltered; in those, the diacetyl is more restrained even as the hop flavors are more pronounced. They’re fantastic beers, the kind you could travel a long way to drink—but that wisp of diacetyl is still there.

“If there’s no diacetyl in a Czech lager,” Fišera says, “then something is wrong.”

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Yeast Selection: Maybe Not as Important as You Think

In trying everything to capture that Czech flavor, it’s understandable if you’re going for yeast sold as “Czech”—and you could do worse than starting with something like White Labs WLP802 Czech Budejovice (i.e., Budvar) or Wyeast 2001-PC (i.e., Pilsner Urquell).

However, there are plenty of Czech brewers making great lagers who don’t put that much thought into their yeast. Many are using house yeasts that originated with other Czech breweries, such as the Gambrinus strain. Others are using various commercially available lager strains, “Czech” or otherwise.

The thing is, yeast don’t have nationalities. If they could laugh, they’d (ahem) split their sides at how we put them into little geographic boxes. Remember, Joseph Groll took Bavarian lager yeast with him when he went to Plzeň. Fermentis SafLager S-23, for what it’s worth, is similar in genetics and flavor profile to Wyeast’s Urquell strain, even if it’s marketed as “originating in Berlin.”

Some of the best lager in Prague right now is coming out of Dva Kohouti. Their flagship Místní Pivo is made of Czech-grown pilsner and Munich malts, a double decoction, Saaz and Saaz Special, nonpressurized fermentation before spunding, a few weeks of lagering—and then it’s poured with practiced skill into chilled, dimpled, half-liter mugs via Lukr side-pull taps.

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Místní Pivo is delicious, and it’s Czech as hell. But the yeast? It’s that global workhorse, 34/70.

Even the ales at Prague’s Dva Kohouti are decocted, to promote foam stability in that gorgeous head.

Assembling the Pieces

Czech malt, Czech hops, decoction mashing, cold fermentation, perhaps a kiss of diacetyl, and—why not?—Czech yeast. Do you need all these elements to brew a convincing Czech-style lager? No. You need only most of them—and then you need to fulfill that promise with careful attention to pouring, foam, and presentation.

But if you need to distill this down to just a couple of elements, go with the ingredients and the decoction.

“Decoction is the centerpiece, I think,” says Tomsa at Dva Kohouti. “If you do that, you can use even standard Fermentis [SafLager] W-34/70 to a good result, I would argue.

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“Overall, I would stress that all those things together make it a true Czech-style lager. You can substitute one, maybe, and it might still work. But you can’t take your standard lager, add Czech yeast, and think that it will make it Czech lager.”

Given the complexity of brewing chemistry, every detail matters. There are no true shortcuts because they’ll only take you to a different place—and that place might be another great lager, but it won’t necessarily taste Czech.

“Brewing is balancing on the edge,” says Berka, the brewmaster emeritus. “If you want something improved, there is something on the other side you are losing.”

It might be that you’re losing some of that convincing Czech flavor. Or it might be that you’re losing some of that elusive quality that Czech lager brewers have spent more than 180 years perfecting.

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Damn it. Why is my mug empty again?

Presentation Particulars

One of the most compelling things about Czech beer culture is the focus on pouring beautiful glasses of beer. A phrase often repeated there is, “The brewer brews the beer, but the tapster makes it.” You can’t separate this part of the experience from the satisfaction of drinking it.

Beyond funny photos of glasses full of nothing but foam, there are some important mechanics at work in the way Czechs pour. The first principle is that the more carbonation the tapster leaves in the beer, the greater the expression of bitterness. Break that CO2 out of solution in the form of foam, and the experience will be softer and sweeter. The second principle is that beer is best poured under foam 1 and not on top of or through it. Tapsters will tell you this protects the beer from oxygen, but this process of submerging the tap and pouring from inside tends to create a more persistent foam that’s a bit less volatile. A flow-control valve on the side of the faucet and a microscreen inside allow controlled foam creation inside the tap, rather than when beer falls through the air and hits the glass.

That said, there’s more than one way to properly pour Czech lager, and some current messaging about Czech pouring can be difficult to separate from the branding of the breweries behind said pours. Let’s start with the hladinka 2, the classic Czech pour and the way that most beers in the Czechia are poured. First things first: Pilsner Urquell and Budvar (Czechvar in the United States) use slightly different pouring processes, with Budvar’s more akin to the Guiness two-stage pour; the beer sits for 30 seconds before the fill is completed. Pilsner Urquell’s pour is in a single motion, with the tap about one-third open to build foam before it’s fully opened to fill the rest of the glass. The result of both methods is a beer that looks like 40 percent foam—but if you were to allow all the foam to become liquid, that liquid would hit the 500 ml line on the mug. (We tested this, just to make sure.)

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The šnyt pour 3 can also be found in neighboring Germany (as schnitt); it generally equates to a half-glass (and is typically priced accordingly). This pour will soften up a bitter beer, but it’s often a drinker’s last one of the night. If you can’t stay for a full beer, order a šnyt.

The mlíko or “milk” pour 4 may draw the most ire from American and British drinkers, but it’s a novelty—only a tiny fraction of Czech beers are poured this way. If you want to down a beer fast, this is the way. Not pictured: the čochtan, a minimal-foam pour that amplifies bitterness via the zip of more carbonation.

We heard it said that “foam is a sign the tapster loves you,” and we couldn’t agree more. There’s nothing in the world better than thoughtfully brewed beer served by a tapster who takes the utmost care to serve it. —Jamie Bogner

Beyond Saaz

There are several varieties of Czech hops that might be of interest to brewers who want to develop lagers with more distinctive profiles. Many are also viewed as more sustainable or climate-hardy alternatives to lower-yielding landrace varieties. Leaving out some of the more established (if under-appreciated) varieties such as Agnus, Kazbek, Premiant, Sládek, and Vital, here are a handful of lesser-knowns:

  • Boomerang (alpha 10–14%, beta 5–10%), a spicy bittering variety.
  • Gaia (alpha 12–15%, beta 5–10%), a bittering variety with fruity leanings.
  • Mimosa (alpha 1.3–2%, beta 6–8%), a new low-trellis variety, lemony, herbal, and floral.
  • Saaz Comfort (alpha 4–7%, beta 3.5–5.5%), distinctively spicy, herbal, and floral, with higher alpha than classic Saaz.
  • Saaz Late (alpha 3.5–6%, beta 4–6.5%), not a late-harvest Saaz but a newer variety, similar to classic Saaz but more citrus and herbal than floral.
  • Saaz Shine (alpha 2–5%, beta 2–4%), pronounced sweet herbal notes, soft lemon, and yields 50 percent higher than classic Saaz.
  • Saaz Special (alpha 4.5–8%, beta 5–11%), an amplified Saaz aroma profile and higher alpha and beta acids.
  • Saturn (alpha 6–8.5%, beta 3.5–4.5%), sweet, fruity, and floral.

About this Reporting

The Czech Ministry of Agriculture supported our travel to the Czech Republic for this reporting, including a series of deep-dive podcasts available at beerandbrewing.com/podcasts. While there, we also joined a trade mission of American and Canadian brewers invited to learn more about Czech brewing and ingredients; during that mission, the Ministry covered our travel expenses. We remain, however, editorially independent—none of the content from that trip was directed, reviewed, vetted, or restricted by the Czech Ministry. —Joe Stange & Jamie Bogner.

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