The Session #36: Kellerbier – Cask Conditioned Lagers

Welcome to The Session – a collaboration of bloggers writing on a common beer-related topic. For February, Thomas Cizauskas over at Yours for Good Fermentables chose Cask-Conditioned Ales as the collective topic to explore. A round-up of all blog posts for this topic can be found here.  You can read more about Beer Blogging Friday (“The Session”) over at the Brookston Beer Bulletin. 

This month’s Session topic lines right up with an existing blog post that I had been kicking around in the background for some time. As part of our blog’s exploration of Niche Beer Styles, one particular style that I’ve had my eye on for some time was called out during Thomas’s announcement of the topic – “can lagers be cask-conditioned”. The answer: hell yeah! The Germans have been doing it since the Middle Ages in the form of Kellerbier.

Hailing primarily from the Franconian region of German, Kellerbiers are unfiltered, unpasteurized, cask conditioned lagers typically served via gravity pours in local German watering holes. In fact, the style has even been reported to be ranked as one of the most popular beers served in the beer gardens around Bavaria. But this of course begs the question, if it’s so popular over there, why is this German cask beer a relative obscurity here in the States? The reality is Kellerbiers are an unstable beer with a short shelf life and an aversion to traveling. Being unfiltered, the yeast will eventually break down causing the beer to deteriorate. As such, Kellerbier is typically reserved for the local market around the small, local breweries that produce it.

Kellerbiers are brewed to the similar strengths as a Marzen (5-5.5% ABV) resulting in a non-sweet malt character with hints of nuttiness. Liberally dosed with aromatic noble hops, the beer is both balanced and drinkable. After being brewed and completing primary fermentation, Kellerbier is traditionally placed in wooden casks where it lagers and matures for several months at cool temperatures. When ready for distribution, the beer is rolled out and served right from the cask it matured in. The casks are typically left unbunged resulting in minimal carbonation, and, like the other cask beers, it allows the ambient environment to work its way into the cask to add its unique character to the beer. The cask conditioning “mellow-ness” further adds to the beer’s perceived dry, drinkable finish.

The US market rarely sees a traditional Kellerbier – most examples have deviated from authenticity in the trade-off to reach the larger population. The quintessential imported Kellerbier here in North America is probably the St. Georgen Brau Kellerbier, brewed in the Buttnheim brewery since 1624. The St. Georgen Brau beer has been labeled as “a happy medium between authenticity and the dictates of modernity” (BYO, 2005). St. Georgen Brau cask conditions in oak casks the traditional way, but used a modern, oxygen eliminating bottling line to stabilize the product for long distance distribution.

Of course other examples can be found in the US, although most are reserved for limited or special release batches from the brewery or brewpub. Brooklyn Brewery’s Brooklyn Keller Hells, Harpoon’s 100 Barrel Series Kellerbier, and Devils Backbone Brewing Co.’s Natural Born Keller are all examples you could seek out, although you may need a little luck to find them.

For those of us who are of the homebrewing bent, brewing a Kellerbier yourself allows you to enjoy this beer style ‘gem’ while eliminates its biggest deterrents – the short shelf life. As a place to jump off from, we’ve listed below is slightly modified version of a Kellerbier recipe from the November 2005 issue of BYO magazine. Why not give it a try?

Caveman Kellerbier
(5 gallons, all-grain)

OG = 1.056, FG = 1.014, IBU = 35, SRM = 15, ABV = 5.4%

Ingreditents
8.0 lbs (3.6 kg) German Pilsner Malt
3.75 lbs (1.7 kg) Munich Malt
2 cups French oak chips (light to medium toast)
8 AAU Hallertauer Mittelfruh or Hersbrucker hop (bittering) (2oz of 4% alpha acid)
1.5 oz Hallertauer Mittelfruh or Hersbruker (flame-out)
Southern German Lager Yeast (i.e. WLP838, Wyeast 2206)

Step-by-Step
Prior to brew day, make an “oak chip tea” by mixing 2 cups of oak chips to 180°F water. Cover and let it cool off – keep refrigerated at least overnight. Save the oak tea until pitching time.

On brew day, either a traditional multi-step infusion mash (122°F dough in for 30 minutes, 148°F for 15 minutes, 156°F for 15 minutes, 170°F mash-out) or a 152 -154°F single infusion mash should be carried out. Sparge until adequate pre-boil volume (pre-boil gravity should be 1.050). Boil for 90 minutes, adding the bittering addition 15 minutes into the boil. At flame-out, add the aroma/flavor hops. Cool the wort down to pitching temp (48°F). Strain out the oak chips from the tea and add the oak tea into the fermentor. Pitch enough healthy yeast, aerate, and hold the temperature at 48°F for primary fermentation (~2-3 weeks). Rack the beer to a clean carboy and raise the temperature for 2 days to perform a diacetyl rest. Rack the beer again, but do not prime it. Let it mature unpressurized for about two months at typical cellar temperatures. Do not rack again – serve and enjoy.

If you’ve been lucky enough to have a good example of the Kellerbier style, please let us know about it.

Slainte!

-The Wallace Brothers


“Beer…because none of the world’s problems were ever solved with white wine.”
-Karl Wichmann