Bohemian Pilsener

Czech or Bohemian-style Pilsener is one of those styles that many new brewers want to learn to brew perfectly. While still crisp like other Pilsener-style beers, Bohemian-style Pilsener has a spicy hop character and a nice, rich, complex maltiness. Bohemian-style Pilsener  usually has a bit more malt sweetness than German-style Pilseners, which helps counter the substantial hop bitterness, making it a more balanced, well-rounded beer.

Back in 1842 Bohemian Pilsener was the first clear, pale-colored beer. Even though it was the palest beer back then, Bohemian Pilsener tends to be slightly richer in color than many “modern” Pilsner beers. It ranges from very pale gold to a deep burnished gold. Just as the measure of what is the lightest colored beer style has shifted over time, today there is also a shift occurring when it comes to describing beer styles. What was “high gravity” and “hoppy” just ten or fifteen years ago, means something different on today’s beer menu. With the advent and popularity of styles such as Imperial IPA and the hop/alcohol creep that has occurred (mainly on the west coast of the US) over the past few years, the beer that the average brewer or drinker has in mind when you say “hoppy” has shifted. When I started brewing, the material I read often described Bohemian Pilsener as a hoppy beer. While Bohemian Pilseners should have an obvious hop flavor and aroma, don’t expect a big, bursty hop aroma or over-the-top flavor. Obvious but integrated is perhaps a better way to describe the hop character of Bohemian Pilsener. The BJCP style guidelines describe the hop character as a complex and pronounced spicy, floral hop bouquet. That is a good description, but don’t think it means a bold hop character. Bohemian Pilsener is rich, but not heavy. Bitter, but not without balance. Hoppy, but without covering up the malt. Clean, but not without fermentation character. The malt character is bready and in balance with the hop flavor, hop aroma, and hop bitterness. Not too bold on either front, these characteristics are just strong enough to be obvious to the drinker. When tasting a well made Bohemian Pilsener, all of these flavors seem to end at the same time in the finish.

I prefer a nice continental Pilsner malt for brewing Bohemian Pilsener. You can use other pale malts if you have no other option, but the light, grainy taste of high quality Pilsner malt is right on target for this style. That is all you need for a great Bohemian Pilsener. You can enhance the malty flavors with a small addition of Vienna, light Munich or melanoidin malt, but keep the percentage to less than 5% of the grain bill. You don’t want to overdo the clean, restrained malt flavors of this beer and you never want to add things like caramel malts. The sweetness and flavor of caramel malts add the wrong character. There is one exception, which is head and body forming dextrin malts such as Carapils. These malts have very little flavor impact, but it is best to keep these between 0 and 10% of the grist.

Extract brewers should use a Pilsner-like malt extract that attenuates in the range of 70% or more. Most light-colored extracts will attenuate fairly well and should be close enough. There are several good Pilsner or pilsner-type extracts out there, so finding one should not be too difficult for most brewers.

Historically, a brewer would use a decoction mash when brewing a Bohemian Pilsener and some breweries still use this time proven method with under-modified malts. While a decoction mash might produce some subtle differences, I find that high quality continental Pilsner malt and a single infusion mash will produce a beer every bit as good as the best commercial examples and even a best of show winner. It is far more important to pay attention to fermentation, sanitation and post-fermentation handling than worrying about decoction. If you’ve ensured that all of those other aspects of your process are flawless, then maybe it is time to worry about decoctions. Of course, there are still breweries in the Czech Republic that brew their Pilsener with a decoction mash. Tony Powell, Head Brewer at Fish Brewing Company is also a big proponent of decoction. He reports that on a recent trip to Europe he found a number of brewers still passionate about decoction mash as a critical component of their process. If you want to brew this style in a traditional manner also, go with a double decoction, open fermentation and a minimum of 45 days of lagering.

I like to avoid any work I really don’t have to do, so I prefer a single infusion mash. I target a mash temperature range of 152 to 156 °F (67 to 69 °C). If you are making a lower gravity beer, use the higher end of this temperature range to leave the beer with a bit more body. While this may seem like a fairly high mash temperature, keep in mind that lager yeast will consume more of the tri-saccharide maltotriose than the average ale yeast. While we don’t want bock-like body, we do want the fully attenuated beer to still have a fairly full mouthfeel.

I’ve never been a proponent of messing with brewing water needlessly, but for Bohemian Pilsener I make an exception. Many commercial breweries typically use water with a low mineral content and it makes a significant difference.

You can make a fine example of the style with most water, but low carbonate water helps match the character of the classic examples. You can build your water from scratch, but if your water has moderate alkalinity and you just want to get in the ballpark, try mixing your filtered tap water 50/50 with reverse osmosis or deionized water. If you have highly alkaline water, use a 25/75 mix of tap to reverse osmosis or deionized water. It is important not to use all reverse osmosis or deionized water with no mineral additions, as it lacks the buffering capacity and necessary minerals for all-grain brewing and for ideal fermentation.

In this style, hop flavor and aroma should always be present and should range from low to moderate. I really like using Czech Saaz hops, though sometimes they’re hard to source. While many consider Czech Saaz hops a must in this style, you do have some flexibility. The trick is to select hops with that same spicy character. You don’t want anything fruity or citrusy. Some decent substitutions are Tettnang, US Saaz, Polish Lublin, Sterling, Sladek, Ultra and Vanguard. If you can’t source one of those substitutions and are determined to brew, you can get away with Hallertau, Spalt, Perle or Tradition. It is really the overall impression that matters. The big picture is that you want moderate hop character and a firm bitterness, but both should complement and integrate well with your malt and yeast choices. The balance of bittering versus malt sweetness should always be to the bitter side. You want a firm bittering presence, one that is obvious but not harsh. The bitterness to starting gravity ratio (IBU divided by OG) ranges from 0.6 to 1.0, but I like to target around 0.7 to 0.8.

A good Bohemian Pilsener isn’t as clean as your typical German or American Pilsner. There aren’t obvious fermentation flaws or anything “unclean” about the beer, but there is a very subtle background note of fermentation-derived compounds that add a certain fullness and interest to the beer. Some may point out the BJCP style guide’s acceptance of diacetyl in this style. Yes, I suppose that is acceptable in very small amounts, but I don’t think it is something to shoot for. In many cases I believe it may not be present at the brewery, but it is instead a fault that develops in the package with the oxidation of alpha-acetolactate into diacetyl over time.

You can ferment Bohemian Pilsener with almost any lager yeast, though my favorites are White Labs WLP800 Pilsner Lager and Wyeast 2001 Urquell. Other excellent strains are White Labs WLP802 Czech Budejovice Lager Yeast and Wyeast 2000 Budvar Lager, 2124 Bohemian Lager, and 2278 Czech Pils. You need around 400 billion clean, healthy cells to properly ferment 5 gallons (19 L) of this beer, which is double what you would use for an equivalent strength ale. For a simple, non-stirred starter, one package of liquid yeast in 2.3 gallons (8.7 L) will result in the right amount of yeast. If you’re not making a starter, you’ll need about four packages of liquid yeast. If you’re using dry yeast, use approximately 3⁄4 ounce (20 g) of fresh, properly rehydrated yeast.

When making lagers, I like to get the wort down to 44 °F (7 °C), oxygenate and then pitch the yeast. I let the beer slowly warm over the first 36 hours to 50 °F (10 °C) and then I hold this temperature for the remainder of fermentation. This results in a clean lager, with very little diacetyl. The idea is to reduce the diacetyl precursor alpha-acetolactate, which the yeast create during the early phase of fermentation. With a warmer environment, the yeast form more alpha-acetolactate and the finished beer contains more diacetyl. Given time and the proper conditions, active yeast will convert the diacetyl to other compounds with a higher flavor threshold, but the lower the initial amount of diacetyl, the less there will be in the final beer. If you start or ferment your lager warmer, you will need to do a diacetyl rest during the last part of fermentation. To perform a diacetyl rest, warm your beer up about 10 °F (6 °C) until fermentation is complete and the yeast have had a chance to eliminate the diacetyl. In any case, don’t rush things. Good lagers take time and they ferment slower than ales, especially when fermented cold. Once the beer has finished fermenting, a period of lagering for a month or more at near freezing temperatures can improve the beer.

Step by Step

Bohemian Pilsener

Ingredients

Step by Step

Issue: November 2009