Pop His Pils: Aaron Hermes of Leesburg won the Pilsner Urquell homebrewing competition. (Noreen Burns)

The classic Pilsner Urquell from the Plzensky Prazdroj brewery in Pilsen in the Czech Republic contains a single variety of pale malt and a single strain of hops. But it’s a notoriously difficult beer to clone.

I learned this while helping to judge the Pilsner Urquell Master Homebrew Competition last Wednesday at Smith Commons on H Street NE. The event, which drew entries from 32 area homebrewers, was sponsored by Tenth and Blake Beer Company, the MillerCoors specialty division that markets Pilsner Urquell in the United States.

Joining me on the judging panel were two senior trade brewers from Tenth and Blake, certified beer judge Charlie Gow and third-generation brewmaster Vaclav Berka, who’s been brewing Pilsner Urquell for 31 years. We were supposed to evaluate the beers primarily (70 percent) for adherence to the Bohemian pilsner style that Pilsner Urquell pioneered, with some leeway for original flare. I don’t know if my tasting notes (which grew sparser as the evening wore on) were any help to the contestants, but I was happy that my picks for best of show were generally in sync with my more experienced colleagues.

Most of the homebrews were quite quaffable, but even the better samples missed their mark by a hair’s breadth or two or three. Fifteen were eliminated beforehand for being a shade too pale or dark. A few beers had a sugary, candylike sweetness instead of the richer, partly caramelized malt character of Pilsner Urquell. One sample had a lovely, piquant hop character, but it was a citrusy hop instead of the dry, peppery Saaz strain that the Czech Republic is noted for.

Diacetyl led to a few eliminations. This chemical, a byproduct of the fermentation process, can lend beer a buttered-popcorn flavor when present in sufficient quantity. Pilsner Urquell exhibits a trace of diacetyl (although that seems to have diminished since the brewery switched from oak fermenters to stainless steel vessels in the early 1990s). This trace results in a fuller, more rounded malt body that distinguishes Bohemian pilsner from related categories like German pilsner or international pilsner. A few of the homebrews either were on the thin side or had a cloying sweetness that manifested itself as the sample warmed up.

Six of the beers were quite close to the original. I nudged Berka at one point and suggested that he might want to recruit some of the brewers before they set off to found competing breweries.

The winner, when all was tasted and tallied, was Aaron Hermes of Leesburg, a 12-year veteran of the homebrewing hobby. Did I mention that more than bragging rights were at stake — that the winner receives an all-expenses-paid trip to Pilsen for himself and a guest? “I didn’t realistically think I had a shot,” Hermes admitted. “My wife is Czech. She drinks IPAs a lot, but whenever I try to brew a Czech beer, she says no, it doesn’t taste right.”

IPAs have indeed replaced pilsners in the hearts of craft beer connoisseurs, but pils has an equally colorful history. Pilsner Urquell traces its roots to 1842 (October 5, to be exact), when a German brewmaster named Josef Groll, hired by the citizens of Pilsen to improve their beer, combined English malting techniques with the city’s excellent soft water supply and a German fermentation regimen to produce the world’s first pale golden lager with a snow-white head. Groll’s beer was an instant sensation. Among other ripples, it induced drinkers to start quaffing their beer from crystalline glassware instead of the traditional opaque mugs.

Pilsner Urquell has a spicy hop character and finishes fairly dry. The lingering bitterness causes the drinker to take another sip to soothe his palate with the soft, bready maltiness up front. The result is a kind of seesaw effect between bitter and sweet. As Berka explains it, “The beer creates a feeling that you are thirsty, and your brain sends a signal to your right or left hand to grab a glass and solve the problem.”

Fortunately, the archetypal Czech pils measures only 4.4 percent alcohol by volume, which is less potent than most American mass-market pastiches of the style, such as Bud or Miller or Pabst.

The Plzensky Prazdroj brewery, explains Berka, uses a triple decoction method to make its beer. This involves removing portions of the mash, heating them in a separate container, then returning the hot barley broth to the first vessel to raise the temperature of the mash as a whole. Berka swears that the complicated procedure is necessary to give the beer its complex malt character.

Production time for a batch of Pilsner Urquell is five weeks. The leisurely cold fermentation allows off-flavors to bubble away and gives the beer its crisp, clean, well-integrated flavor. The roastiness of a stout and the hops in a double IPA will hide a wide range of defects. But a pilsner is like a model in a swimsuit — any imperfection will show immediately.

“Czech pilsners are one of the most technical and difficult styles to brew,” notes veteran D.C. homebrewer Nathan Zeender, who finished second in the contest.

Several excellent domestic pilsners are available locally. Victory Prima Pils and Tuppers’ Keller Pils are aromatic, highly hopped examples of the style, more aggressively flavored than most of their European counterparts. Stoudt’s Pils is an immensely drinkable summer refresher. A rookie-of-the-year award must go to Rhino Chasers Pilsner from the recently opened Lost Rhino Brewing Co. in Ashburn, which combines Saaz hops with the more floral Hallertau variety.

The best American pilsner I’ve ever tasted, however, is Live Oak Pilz from a microbrewery of the same name in Austin, Texas, that, alas, doesn’t distribute out of state. The hops and malt are in an almost perfect equilibrium. Note the unusual spelling: Pilz means “mushroom” in German. No fungi (other than the yeast, of course) are used in brewing this beer. But the final “z” gives the beer a certain etymological correctness. The name Pilsen derives from an old Czech word meaning “damp” or “moist” — perfect conditions for growing mushrooms, whose earthy, savory flavors would pair well with a tall glass of pilsner.