Book Excerpt: Brewing a Světlé Pivo

As the last post in Homebrew Week, I offer you a complete chapter from The Secrets of Master Brewers. Whether you brew at home or not, this chapter will give you the sense of this book and what you'll find inside. It's great for homebrewers or people just interested in fully understanding beer styles. If you enjoy it, go buy the whole book.


Almost all serious beer fans know that pilsners came from Plzeň (Pilsen) in Bohemia. It is the world’s most famous style and is imitated in greater or lesser ways in every country that makes beer. What they are less familiar with are the světlý ležáks and světlé výčepnís — pale lagers — as they are made and consumed in their homeland. From a great distance all Czech pilsners look alike. If pressed, drinkers might admit that hoppy Pilsner Urquell, with its very round body and dollop of diacetyl, isn’t actually that much like the drier Budvar, with its subtle kiss of bitterness. But eh, really, they're yellow and fizzy and mostly all the same, right?

If you spend time in more than a couple of Czech pubs, however, it quickly dawns on you that this is completely wrong. Let me offer an analogy by way of thought experiment. Put your mind on hoppy American IPAs, which from a great distance also appear a lot alike. Now imagine the perspective of a foreign beer drinker — a Czech, say — who believes he understands the style well enough because he has ready access to Dogfish Head 60 Minute IPA and New Belgium Ranger. Would you say he has an adequate understanding of American IPAs based on his sample of two beers? This is why knowing Pilsner Urquell and Budweiser Budvar does not give you a complete sense of světlý ležák.

The truth is that within the confines of just a few ingredients breweries have managed to create beers with a range nearly as broad as American IPAs. I have had the good fortune of visiting the Czech Republic twice on fact-finding missions (both in pubs and breweries) and have come to marvel at the differences in some of my favorite pivos: Únětické 12°, with its rustic haze and electric hops; creamy Pilsner Urquell, the unfiltered version of which is a revelation; thick, very stiff Kout na Šumavě, a beer some say is the best in the world; Na Rychtě Mazel, which slyly hides its luxurious honeylike malts behind a wall of Saaz; and the mysteriously deep golden U Tří růží Světlý Ležák, which seems to have a touch of stone fruit on the palate.

Because the ingredients, beer to beer, are so similar, these differences come largely from technique. Whether breweries are using double or triple decoctions, long boils, open fermentation, extra-long maturations (or shortened ones), filtering or not filtering — all these choices shape the flavors each brewery wants. If you don’t have the opportunity to visit Prague and taste these beers yourself, you can at least experiment with brewing methods and see how varied they can be made at home.

When you sift through the history of beer and brewing, it becomes clear that single-origin histories usually turn out to be myth. Finding the one guy who did X is like finding the pot of gold at the end of the rainbow. Beer styles almost always evolve incrementally, with many fathers of invention. One very notable exception is the origin of pilsner, which we can trace back to Josef Groll (Brewer X?), a brilliant, dyspeptic Bavarian who briefly took a job in Bohemia and brewed the world’s most important batch of beer there.

We start the story in 1838, when the beer situation in the small town of Pilsen had gotten so bad that the town fathers rounded up 36 barrels of inferior ale and dumped it in the town square. To rectify the woeful state of affairs, they decided to build their own brewery, and they wanted it to be the good stuff, the “Bavarian” beer (lager) that was starting to become popular in Bohemia at the time. The town fathers hired an architect, built a malt house and brewery, and set off to Bavaria to find the man to brew it. They brought back Groll, who etched his name in the history books by brewing a startlingly pale, coruscating lager on October 5, 1842. Thus was born pilsner beer. (Groll, described by his own father as “the rudest man in Bavaria,” lasted only three years before he was sent packing — but by then he’d changed the world.)

That brewery came to be called Plzeňský Prazdroj — Pilsner Urquell — the fountainhead of pilsner — and as noted the only “pilsner” you’ll find in Bohemia. When I visited one of the brewery’s chief rivals, Budvar, the master brewer, Adam Brož, said, “It’s really difficult to compete with Pilsner because it [defines] the style. It became the style of the pilsner type.” His beer, he said, was not a pilsner. In old Bohemia Prazdroj’s beer became immediately popular and began to influence other breweries.

Within decades the style was hopping international borders and inspiring imitators as far away as St. Louis and Milwaukee. Pilsner’s most famous brewery led the international charge, shipping their beer across Europe and across oceans. As Urquell’s current master brewer, Vaclav Berka, says, “Before the outbreak of World War I, the Burghers’ Brewery had distributors in 34 countries worldwide.”

Today visiting the brewery is a bit like making a pilgrimage. Pilsen is still a small town, and from the town square you can see the water tower across the Radbuza River from downtown — it’s as dominant a feature on the skyline as the spire of St. Bartholomew. The campus sprawls over 89 acres, with beautiful nineteenth-century buildings gathered around a central cobblestone boulevard. Equally as impressive are the 9 kilometers of cellars beneath the brewery, carved out in a preelectricity age to house slowly maturing pilsner. The pièce de résistance of any tour is a cup of fresh beer straight from a wooden tank — consecrated water from the cathedral of beer.

Pilsner runs through Vaclav Berka’s blood — or bloodline. His father oversaw the fermentation department, and as a boy Berka would wander those long cellars where beer sat ripening. He stayed in the family business, studying fermentation in college. He interned at the brewery in the summer and brewed his first batch of pilsner at the tender age of 16. In 1980 Urquell gave him a job, and he briskly climbed up the ladder, becoming the chief of maturation within just two years.

More importantly, Berka was there after the 1988 Velvet Revolution that would ultimately bring privatization to Urquell. He was involved in the process of modernizing the brewery and converting his beloved old wooden vats to stainless and over the course of years worked to perfect a system that produced beer with the character of the original. He has worked in different capacities as brew master and currently holds the title senior trade brewmaster.

Every beer-drinking country has a particular relationship to the beer it brews. In the Czech Republic, unlike many places, beer is treated as both a less exalted beverage and one more necessary; it’s elemental, like water. You don’t find Czechs rhapsodizing about their světlý ležáks the way American beer geeks do. Those displays are for luxuries. For Czechs pivo is a staple, mundane as the air they breathe but just as central to life. (It hardly bears repeating the well-worn statistic that Czechs, at 143 liters of beer per person per year, far outdrink their closest rivals, the Germans, who put back a mere 110.) The vast majority of the beer Czechs drink is světlé pivos — pale lagers between 10˚ and 12˚ P (1.040 and 1.048).

In the United States we describe a style known as “pilsner” that is divided into two categories — German and Czech. According to this view, the difference is basically hops — there are more of them in the Czech pilsner, and they consist of that gloriously intense hop type, Saaz. German pilsners are less bitter and employ more sedate, lightly herbal German-grown hop varieties. Other than that, they’re basically the same beer.

This view is flatly wrong.

There are several distinctions, but the big difference lies in the base malt and the way that malt is used in the mash. All světlé pivos are made with decoction mashing, while fewer and fewer German breweries hang on to this old practice. The decoction process was originally used to make sure undermodified malt was fully converted during mashing. But it has an effect on the flavor and feel of a beer, too; the process of pulling out a portion of the mash and boiling it creates melanoidins, compounds that occur during Maillard reactions that both flavor the beer with bready or toffee notes and give it a rounder, richer maltiness.

At Budvar brewers ran an experiment in which they made their beer with a step mash and compared it to decoction mashing. Master brewer Adam Brož describes the results. “We compared decoction versus infusion in our small-scale brewery; always the beer brewed by the infusion process was emptier in its taste — the body was not correct for the lagers. Also the color changed. If you boil during the decoction, you prepare the compounds that cause golden color. So the infusion lagers were yellowish, not so full in their taste.”

Because decoction is ubiquitous in the Czech Republic, many breweries use floor malts or malt their own barley, and they shoot for a quality that is rich and aromatic. This has been the case at Pilsner Urquell since it was founded, and it is still critical, since the brewery goes through a full triple-decoction mash. “While most brewers purchase malt from external suppliers,” Vaclav Berka says, “the Plzeň brewery makes its own malt to be sure the product meets all criteria.” The result is pale lagers with far more malt character than those across the German border. They are hoppier, for sure, but the malts are also more obvious — the equal of that stiff dose of Saaz in světlé pivos. Even among the German breweries that still use decoction mashing, the profile is a lighter, less malty beer. A helles is far closer to a German pils than the latter is to a Czech pils.

Světlé pivos are deceptively simple beers: pilsner malt (which is called “pale malt” in the Czech Republic), Saaz hops, and soft water. This is the most basic formulation, and the one most often used. The Czech Republic is starting to develop a craft brewing scene, and many local breweries are experimenting broadly — but not with their světlé pivos. A brewery may use a tiny bit of specialty malt or bitter the beer with Sládek or Premiant, but they would not deviate very far from the expected palate for this style of beer.

But that doesn’t mean a brewery doesn’t have room to put a stamp of originality on their světlé. Mashing regimes vary (double decoction is most common, but Urquell and others still do triple), with rest lengths and decoction practices differing brewery to brewery. Barley types and malt sources vary and, as in England and Germany, create different flavors. Boil lengths are typically 90 minutes but are sometimes as long as 2 hours. Some breweries use relatively few hops, while others load in bales. Conditioning times run the gamut from three weeks to three months.

In some ways the Czech světlé pivo is a more homebrew-friendly beer than a Bavarian lager. German brewing is now so refined and precise that replicating it on the home system is a challenge. Czech lagers are a bit more variable, and rusticity isn’t necessarily a bad thing. A popular presentation in pubs is nefiltrované pivo, or unfiltered beer, and kvasnicové pivo, which literally means “yeast beer” and is also cloudy — something like German kellerbier.

In some regions of the United States, a haziness is considered a mark of artisanal authenticity, and that expectation is starting to happen in the Czech Republic, too. When Únětický Pivovar, a Prague-area brewpub, first released their two světlé pivos, they had shortened the lagering period to get them out on the market. They were hazy and not fully smooth — and people loved them. When they did start lagering for a month and introduced a bright version of their beer, people demanded the more rustic version. Or take Urquell, which in the Czech Republic is considered unusual. It is a světlý ležák — a pale lager of 12˚ — but at 4.4% ABV it has a fair amount of residual sweetness. It also contains a detectable level of diacetyl, which adds to the fullness of the beer. Half-liters arrive with mousselike heads and go down like special, rich treats.

  All of this makes světlé pivos great beers for homebrewers to tackle. You’re working with more flavors to begin with, so a little extra character or haziness from the brew system may well give it a delicious je ne sais quoi.

Notes: Berka emphasizes that this recipe is not the one Urquell uses (“The detailed recipe remains secret and is closely guarded,” he told me, “passing from one brewmaster to the next.”), but it is typical for Czech brewing. For the full description of decoction, see Diving Deeper below. Note that decoction processes vary widely, even within the constraints of a two-decoction mash. When you mash in, how long you boil, how thick the mash is — all these things will affect the wort.

Hopping rates and schedules vary dramatically, from the low 20s to over 40 IBUs. First-wort hopping (adding hops to the kettle during lauter and while the wort heats to a boil) is very common. Světlé pivo is not noted for rich aromatic hop additions, but modest late additions are fine. It’s traditional to conduct primary fermentation for one day for every point of gravity on the Plato scale, but you can transfer to maturation whenever the beer reaches terminal gravity.

Yeast variety is not critical, though Berka notes, “Pilsner Urquell is fermented with the ‘Pilsner H’ yeast strain, which has a pedigree dating back to the yeast that Josef Groll used.” A version of that strain is available from the commercial yeast banks. You might need to conduct a diacetyl rest. Diacetyl is a slick, heavy compound that gives beer the flavor of butter or butterscotch; it’s actually a key ingredient in the artificial butter used on popcorn. Yeast will reabsorb the diacetyl naturally. Raise the temperature of the beer to 57˚F (14°C) and hold for two days at the end of primary fermentation and you shouldn’t have any trouble with diacetyl.

We’ve talked about the fullness of body and flavor that distinguishes a světlé pivo from other beer. There’s even a term in Czech to describe this quality. It’s called říz and translates roughly as “cut.” Evan Rail, an American who has been the most important writer on the subject of Czech beer, describes it as the way a good beer strikes you; it can mean “character” or the sharp or full flavor of beer. When you make a světlé pivo at home, shoot for říz.

In the Czech Republic, breweries attain the quality of říz through different means. For a real outlier take the example of Kout na Šumavě, a remote brewery in a town that shares its name with a town two hours southwest of Prague, near the German border. The eighteenth-century building it occupies once housed a much larger brewery, but it had been long abandoned by the time Jan Skala decided to reoccupy it and open Kout na Šumavě in 2006. He brought in Bohuslav Hlavsa, an experienced brewer, to make the beer.

Everything Kout does seems odd. They conduct a 2-hour boil and add hops in three additions — at the start of boil, again after 45 minutes, and finally after 90 minutes. That accounts for the strangely stiff-seeming bitterness, which is sharp and muscular, but only registers at just above 30 IBUs.

The fact that Hlavsa consulted 200-year-old recipes discovered at the old brewery site may account for the long boil as well as the open fermentation and long maturation (3 months for the 12˚ beer) he does later. But the very strange thing is that he also uses a dab of caramel malt in the grist. This is of course a shortcut Americans might take to approximate the flavors and roundness of decoction, but I’d never encountered it in a Czech brewery. (Hlavsa also uses triple decoction on his 12˚ beer.) It turns out that other breweries use color malts as well — though typically Munich rather than caramel. So while decoction is a given, it seems everything else is up for grabs.

In making Czech-style světlés myself, I have used more late-addition hops than is typical but found that most of the effort on late-addition hopping is lost on the beer during lagering. Still, there seems to be no strict rule on when or how many hops may be added — just that they should be in the Saaz family. Hopping is one of the main ways breweries distinguish themselves, and I could envision a future when breweries seek more saturated flavors and aromas from late-addition and dry hopping. I’d consider most hopping experiments largely acceptable as traditional variations.

Start with Bohemian pilsner malt, which was malted with decoction in mind. You’re going to start with a somewhat wet mash of 2 quarts of water per pound of malt. Mash in at 122˚F (50°C), and hold it for 10 minutes.

Next, pull a thick decoction of about a third of the mash. “Thick” here means a third of the barley, leaving behind most of the liquid wort. Enzymes are converting the starch in the liquid part of the mash, so you want to leave as much behind as possible for later steps. Stir the mash, and then remove with a colander. This will allow some of the liquid to run off. You can eyeball the third, too — this system allows for ranges rather than precise measurements. Move this decoction to a kettle (a smaller one if you have it), and begin heating. This decoction mash should still contain liquid — it looks something like a slightly watery porridge.

You’re going to raise the temperature slowly, making sure to keep stirring so that none of the grain gets stuck to the bottom of the kettle and scorches — you don’t want scorched flavors in your světlé. Bring the temperature up very slowly, about 2° F (1°C) per minute if you can manage it. You’re going to raise it all the way to 156˚F (69°C), but the slow rise means conversion will be happening along the way.

Hold it for 10 minutes, then raise it to a boil, and keep boiling for another 15 minutes. If you’re having trouble with sticking grain, it’s okay to add a bit of water to make sure it’s thin enough. Be careful while boiling, because the bubbling mash burps like the mudpots in Yellowstone, and you don’t want to get splashed.

Return the decoction to the main mash. Ladle it over in portions, and watch the temperature of the main mash. You want to hit something in the 144 to 149˚F (62 to 65°C) range for conversion, and since you’ll be building body by boiling during decoction, a lower number in that range is better. If you hit your main mash temperature before you’ve returned the rest of the decoction, stop and let it cool, returning the remainder when the main mash cools down to 150˚F (66°C) or lower.

After you’ve done the main starch conversion, it’s time for the second decoction. Again, pull another thick third of the mash, and heat it in your small kettle. This time there’s no need to stop at a saccharification rest since you’ve already done it in the main mash, and you can slowly bring it to a boil. Even though you’re not looking for conversion during the heat rise, you want to go slowly to prevent scorching.

Return the decoction to the main mash, bringing it to 162˚F (72°C). At this point you’re ready to complete the mash as you would normally. After you boil, ferment, and lager — just another six weeks away! — you can sit down to a pint of your decocted světlý ležák and see for yourself if that extra effort was worth it.