A Taste of History at Pilsner Urquell

Unfiltered Pilsner Urquell

Unfiltered Pilsner Urquell

A Taste of History at Pilsner Urquell

Impressively, over the last 175 years since Pilsner Urquell was first brewed, the beer has changed very little.

The ingredients haven’t changed (the first strain of yeast is still carefully propagated); even when moving to a new brew house they continued to use copper kettles (while most breweries have moved to stainless steel) because the direct heat on the copper kettle creates deep caramel flavors in the mash that wouldn’t otherwise be present in the finished beer.

The main changes have been to the fermentation process and distribution method.

Historically, before the introduction of stainless steel kegs in the 1950s, all beer was racked into wooden barrels for storage, transport, and dispense.

As Pilsner Urquell is a lager, it has a long cold storage, or conditioning, period before it is ready to serve. In a network of cellars below the brewery, hundreds of barrels would sit – first to ferment on the higher level where it was slightly warmer; then they’d move down to the colder, lower level to condition.

Pilsner Urquell cellars
The network of cellars below Pilsner Urquell brewery.

When it was ready, the unfiltered and unpasteurized beer would then be transferred from the large conditioning casks into smaller wooden barrels for distribution and dispense, and sent out to customers nearby.

Modernization beckoned, however.

With advancements like artificial refrigeration (first used in brewing in 1873) and stainless steel brewing equipment (introduced after World War II), eventually the beer would be fermented and conditioned in large stainless steel vats, instead of the traditional wooden casks.

Distribution and dispense also moved away from wooden barrels to stainless steel kegs. Additionally, to help extend shelf life and shelf stability, the brewery began to filter and pasteurize the beer prior to distribution.

And that is how Pilsner Urquell is produced today.

The brewery continues to produce a small volume of beer the old fashioned way, however, in a process called “parallel brewing”.

In order to ensure that these technological advancements have had as small as possible an impact on the flavor of the finished beer,  the beers fermented in the wooden barrels and stainless steel vats are continually compared by the brewmasters.

And it is because of this parallel brewing process that visitors who join for a brewery tour are able to taste Pilsner Urquell as it would have been presented in the past.

Pilsner Urquell historical fermentation
Pilsner Urquell fermenting the old-fashioned way, in large wooden barrels in cellars below the brewery.

After a tour of the cellars, we were guided to the barrel store where we were given a sample of unfiltered and unpasteurized Pilsner Urquell straight from the conditioning cask.

Having only previously been exposed to the filtered and pasteurized bottled version of Pilsner Urquell, the unfiltered, unpasteurized version was far removed from what I was used to.

The Czech Pilsner style (or Czech Premium Pale Lager, if we’re going to get technical) is known for having a pronounced bitterness that’s balanced by rich, complex malt flavors.

When unfiltered, however, the beer’s higher protein content and fuller body blunt the bitterness. Heavier on the palate than the filtered version, it’s still incredibly refreshing and moreish. The beer is still richly malty, but not sweet.

Drawn directly from the wooden barrel, the unfiltered and unpasteurized Pilsner Urquell had a beautiful creamy texture, much like Kölsch when it’s served directly from the barrel, with the help of only gravity, at traditional brewpubs in Cologne.

Flavorwise, there was a slight tang to the unpasteurized beer, likely coming from the time in the barrel. The reason most breweries moved to stainless steel equipment when it became available was because wood was notoriously difficult to keep clean; so lager yeast may not have been the only fermenter present. The tang certainly wasn’t off-putting or overwhelming, however. It was subtle and nicely complemented the full, creamy texture of the beer.

So why do filtration and pasteurization change beer’s flavor, texture, and appearance so dramatically?

Pasteurization is the process of applying heat to the finished beer to kill any remaining microorganisms and help lengthen shelf life and shelf stability. Some studies have shown that “cooked” flavors, from the heat applied during the process, can be detected by expert panels, but in general, pasteurization is thought to have a minimal impact on flavor. (As a note, it’s typically only bottled beer that is pasteurized, hence why it’s shelf stable. Most kegged beer is left unpasteurized, which is why kegs need to be kept chilled.)

Most of the differences in flavor, texture, and appearance are dependent on whether or not the beer is filtered.

Filtered and unfiltered Pilsner Urquell
Filtered and unfiltered Pilsner Urquell; on tap at Na Parkánu in Pilsen.

What does filtration do to a beer you ask? Conveniently, I wrote a bit about this when discussing the recent trend towards hazy IPAs.

These days, most beers are filtered because filtration helps remove yeast and other materials that may lessen shelf-stability and shorten a beer’s shelf life. Understandably, beer brewed for international distribution will hold up better when filtered, so it’s become the norm.

However, over-filtered beer can be stripped of color, flavor, and proteins that are all-important for body and head retention. For the sake of the resulting flavor profile, more brewers these days are embracing the hazy appearance and leaving their beers unfiltered. (Sounds like Pilsner Urquell was onto something 175 years ago!)

For unfiltered and unpasteurized beers, freshness is key, so they’re often kept close to the source. Hence why unfiltered Pilsner Urquell is so hard to come by outside of Pilsen. (Even in Pilsen, there’s only one pub – Na Parkánu – where it’s always available.)

Occasionally, the brewery holds “barrel events” where they’ll (quickly!) ship a barrel of unfiltered and unpasteurized Pilsner Urquell to pubs in various European cities.

If there’s not one near you though, it’s certainly worth making the trek to Pilsen to experience this full-flavored, full-bodied version of the world’s first Pilsner first-hand.

It’s a step back in time; a taste of history at Pilsner Urquell.

Pilsner Urquell in the cellar
Unfiltered and unpasteurized Pilsner Urquell drawn directly from a barrel in the cellars below the brewery. Cheers to a taste of beer history!

(P.S. Wondering what version of Pilsner Urquell is inside their giant tanks propped up in pubs across the UK? Pilsner Urquell tank beer is filtered and unpasteurized, like most kegged beer. For the unfiltered version, you’ve got to go to the source.)


Images by Natalya Watson

Tour at Pilsner Urquell brewery on September 24, 2017
Randy Mosher // Tasting Beer
John Palmer // How to Brew
Beer Judge Certification Program // 2015 Style Guidelines: Beer Style Guidelines