Most great successes in history are preceded by spectacular failures—and it was barrels of rancid ale being dumped in the streets of a brewing-proud Czech city that led to the creation of what is probably the most imitated beer style in the world. You see, something stank in the Kingdom of Bohemia in 1838 (spoiler alert: it was the beer). Whatever the cause (and a good guess would be rampant mutation and contamination in the common top-fermenting brewing yeasts in use), the city of Plzen’s civic and brewing leaders decided that enough was enough and significantly changed the way beer was brewed in their city. The result was Pilsner, one of the first broadly produced lager styles and a beer that has become the mainstay of global beer consumption, production, and emulation.

Though the Bohemians can take credit for Pilsner thanks to geography, it was a Bavarian who gave them the opportunity. The first blonde lager produced in Plzen was brewed by Josef Groll, a German brewer who was tasked with producing an entirely new kind of beer and given a new brewery in which to do it. Using lighter-kilned malts (thanks to English technological advances), locally sourced Saaz hops, the soft water common to the area, and a monk-smuggled (or so the stories go) strain of new bottom-fermenting lager yeast, Groll produced the first Pilsner-style lager in October 1842.

It was an immediate success.

Soon, breweries all over the world were imitating the beer, and the pale, clean lager rapidly became fashionable in cities throughout Europe. In the 175 years since, the popularity of Pilsner has only grown, and it is far and away the most-consumed beer style in the world (upward of 90 percent of global beer consumption, depending on how liberally we apply the “Pilsner” appellation).

But just what are those beer drinkers drinking? And how well does it match the style that Groll and the breweries of Bohemia established? The appeal of the beer was obvious: it was light, flavorful, clean, and easy to drink. As it traveled the world, though, local circumstances led to a fracturing of the beer style into all manner of interpretations thanks to the idiosyncrasies of water chemistry, climate, ingredients, and drinkers’ tastes.

The Pilsner style has almost become shorthand for “beer” itself, and we owe it to Groll, the citizens of Plzen, and ourselves to know what Pilsner was, what it has become, and why its descendants have remained so very popular.

Nowhere to Hide

The four primary brewing ingredients all play their part in constructing a solid Pilsner. There are styles where some are minimal due to a lack of availability (think hops and Scottish ales), lack of visibility (yeast character in a Russian imperial stout), and/or lack of clear style guidance (saison can accommodate almost any combination of flavors since it evolved as a “whatever’s on hand” kind of style). Pilsner, on the other hand, left the ingredients (all of them) with nowhere to hide. This was a naked expression of beer in which all of the characteristics of the ingredients were starkly visible, and that hasn’t changed much over the years. The yeast produces very little, but what it produces is central to the style. There are no aggressive malt flavors to hide behind, and yet there’s a specific malt profile to meet. The hops flavor and bittering level are key to the style. And the water—oh, the water. Well, let’s just say that Plzen had more than a dedicated beer-drinking public going for it. So let’s get into what each of these contributes to Pilsner.

Yeast

Pilsner is quite emphatically a lager, in both historic and modern terms. The cold-loving lager yeast that was (apocryphally) smuggled out of Germany made the beer clean, spare, and far more predictable than the traditional ale yeasts (or wild yeasts) that had fermented so much other Continental beer up until this point in history. The yeast in a classic Pilsner contributes by not (really) contributing. It ferments cleanly, with very few by-products other than carbon dioxide and alcohol. It is also a high-flocculator, so when fermentation is complete, the yeast thoroughly drops out of suspension, leaving a brilliantly clear beer behind. And it does all of this with its parka on—classic Pils yeast will attenuate fully even in temperatures as low as 46°F (8°C). All of this is not to say that the yeast contributes nothing more than alcohol. The classic strains (Wyeast 2001 Pilsner Urquell and White Labs WLP800 Pilsner Lager) also help produce a round, soft malty character in the finished beer.

Malt

Speaking of malt, it should come as no surprise that European Pilsner malt is the grain of choice in Pilsners. It lends a characteristic honey-like sweetness to the beer and is lightly kilned, leaving it with a less-bready background note. Once you have the requisite “Pilsner” flavor in place in your grist, you may then begin to build up the character by adding other malts, to your taste preference. Depending on the regional variation, you may want more toast, more caramel, more biscuit, or none of the above. And it isn’t uncommon to see recipes that use a wide variety of low-Lovibond character malts (Munich, Vienna, Victory, Biscuit) and even some lighter crystal malts (although I would avoid anything higher than 40L).

One malt that might need to be present, though, is a touch of melanoidin malt. Classic Pilsners were brewed using a decoction mash—a time-intensive (but flavor-developing) process whereby a portion of the mash was removed, boiled, and re-added to the mash. In undermodified grain, this increased mash efficiency developed the proteins and enzymes necessary for saccharification. With modern grains (which require no further modification), many brewers consider a decoction mash an anachronistic waste of time. You be the judge, but if you’re going to skip decoction and do a traditional single-infusion mash, you may want a touch of melanoidin malt to mimic the rich bready flavor that decoction would traditionally impart.

Hops

For hops, nothing says “Pilsner” quite like Czech Saaz. Originally, Saaz came with a few natural advantages. First, it was available—Groll, in producing his beer, had access to a ready supply. Second, it is a wonderfully spicy, herbal, and floral hops when used to add flavor and aroma (in addition to bitterness) to a Pilsner. And third, it is a relatively low-cohumulone hops variety. Cohumulone is a component of hops oils that, when present as a higher percentage of the total oil content, can impart a harsh character to the bitterness of isomerized alpha acids. Lower-cohumulone hops can be used in larger quantities to add pronounced hops flavor and aroma while still preserving the softer flavor of a Pilsner. Most noble hops varieties fall at the lower end of the cohumulone spectrum and can thus be used to make a traditional Pilsner. While Saaz is the most common, Tettnang, Spalt, and Hallertau are sometimes used as well.

Water

Water is our last key ingredient—and much like the yeast, it’s most noteworthy for what isn’t there. The local water supplies in Plzen were famously, impressively soft. This incredibly soft water meant that the bitterness imparted by the hops was more like the pleasant, easy stroke of a soft brush than the hard, sharp scrape of a rasp (which was common in most heavily hopped beers in other locales). This meant that hops could be used with abandon and heavily emphasized without running the risk of creating a grating, sharp bitterness. Building up from distilled/reverse osmosis water is one potential method to re-create the water of Plzen, but be sure to add sufficient minerals to enable proper yeast functioning. Yeast cannot properly ferment in water that is completely devoid of minerals and salts, so pure distilled/reverse osmosis water will need to be augmented with brewing salts or natural water. (For more about what you can do about the water profile, see “Brewing Water,” Craft Beer & Brewing Magazine®, Winter 2014

A Question of Style

To recapitulate, properly constructed Pilsner recipes should use flavorful but lightly kilned malts, herbaceous hops that are reminiscent of a walk through a garden in summer, and water and yeast that promote an unadorned and clean presentation of the beer. When Pilsner first came on the scene, it was a beer that anyone could love (and many did) and virtually no one could hate. The original Czech Pilsner became just one variation in a beer that was replicated all over the world, and distinct regional iterations soon became common (and defined in their own right).

There are at least three (and maybe four) commonly accepted styles of Pilsner: Czech (or Bohemian), German, and American (sometimes referred to as pre-Prohibition lager), with “International-style Pilsner” as a potential fourth variation, though its definition is somewhat vague. Each variation exhibits certain characteristics and allows for specific flavors that distinguish each from the others. However, there are definite similarities across the styles. First, none exhibit strong fermentation character such as fruity esters or yeast-derived phenols. This is, first and foremost, a lager. All feature pronounced bitterness and at least some hops flavor, and although it’s a malt that carries the Pilsner name, these are primarily hops-driven beers. Pilsners are also distinguished from other light lagers by their bittering (higher than all other light lagers with the possible exception of some German Exportbiers) and relatively strong flavors. And all exhibit a moderate level of malt complexity, despite their reliance on light malts. From there, though, things do start to vary.

Czech Pilsner

The classic Czech Pilsner, as we’ve described, can be picked out of the crowd in large part due to its commitment to the Czech Saaz hops, which should be featured in both the aroma and flavor. It has a rounded and noticeably malty character, though it retains (as do all Pilsners) a hoppy flavor profile. Bohemian Pilsner also allows for the presence of a small amount of diacetyl (think movie theater popcorn), though its desirability is debatable and it almost certainly isn’t something that should be deliberately included.

German Pilsner

A short trip from Bohemia into Germany yields a very different interpretation of the style. Whereas Czech Pilsners are more of a balanced affair (though, again, still focused on hops), German Pilsners are more Spartan and stripped-down. They are pale, dry (often bone dry), grainy, and more bitter than their Czech cousins. They also allow a small degree of sulfur to carry over from the fermentation, adding a signature flourish to the aroma. Where the Czech Pilsner is more “soft,” German Pils is more blunt.

American Pilsner

About the same time that Pilsner was spreading throughout Europe, it was also making its way across the ocean to America. John Wagner, a Bavarian immigrant, brought lager yeast to the New World in the early 1840s, and by the late 1850s an American version of the Pilsner was commonly available. This “Classic American Pilsner” (or pre-Prohibition lager) had elements of both the Czech and German varieties in that it featured a round maltiness and higher bittering levels, but it also used local ingredients (primarily hops such as the modern Cluster hops variety) that gave it a distinctly “American” flavor.

It should be noted that the modern American Pilsner is not brewed with citrusy “American” hops, but rather with domestically produced variants of the European noble hops. Low levels of dimethyl sulfide (DMS)—or a light cooked-corn flavor—are acceptable, but like diacetyl in the Czech Pils should probably be avoided. Much like their European cousins, American Pilsners were fermented cold (either in caves or dugout vaults near local rivers) and were popular with the locals for their clean, easy drinkability.

International Pilsner

When we fast-forward into the modern era, we also see the rise of “International-style” Pilsners. It isn’t entirely clear that these are Pilsners in the classic sense (they often exhibit limited hops character and very restrained malt complexity), but they are pale lagers that are at least emulating the traditional Pilsners of Plzen and Germany. They deviate, though, in their common use of adjuncts such as rice and corn to enhance their lightness.

Pilsners have come a long way (literally and figuratively). From the banks of the Rabduza River in the Kingdom of Bohemia came the most popular beer style in the world, and it isn’t an exaggeration to say that the popularity of beer throughout the world was greatly enhanced by the creation of Pilsners. In addition to being approachable and enjoyable even for those who might shy away from the stronger flavors of the stouts and porters of the time, Pilsner showed the flavor potential of hops long before the first IPAs came on the scene. They also gave brewers no place to hide faults, thereby rewarding brewers who could demonstrate greater skill in their production processes. And all thanks to a few drain-poured barrels of bad ale.

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PHOTO: MATT GRAVES