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

Niche Beer Styles: Oyster Stout

The craft brewing movement has really perfected the practice of finding niche beer styles, brewing them with passion, and starting a grass-roots movement that hoist these products up to the interest of ‘enlightened’ beer drinkers. Think Anchor Brewing Co. in the 1970’s when it revived to the Steam Beer / California Common niche by launching Anchor Steam Beer. Or the explosion of the Double IPA niche in the late 1990’s after Vinnie Cilurzo (then of Blind Pig Brewing Co.) accidentally created the style. As a gauge of breath of beer styles (niche and mainstream), take a look at this year’s Great American Beer Festival Competition. The event hosted over 70 different beer categories with 3,000+ beers entered amongst them. Only the sharpest of beer geeks could name at least half of the 78 categories, let alone all of them.

In contemplating this, it set off the gears in my head – every niche style out there has a story of how it came to be. The gears kept spinning. Those styles need to be explored. Hey, that would make a good blogging topic. And then, poof... this blog entry wrote itself.

I’ve had stouts on my mind ever since one of the guys from our homebrew club did stout and ice cream floats at the last club meeting. My original thought was to would delve into American Stouts to find out how we Americans bastardized the European standard, but I kept coming back another stout over and over again: the enigmatic Oyster Stout. I’ve only personally run into the style once before (at the now defunct Baltimore Beer and Oyster Festival) and I remember thinking “Who the hell would think to put these meaty morsels into beer?” But you know what, it works. Something about the briny flavor of the oysters mixes with the earthy tones of a stout when its done in balance. Go figure.

While tracking down the style’s history, I came across an informative and relatively short article the beer writer Michael Jackson wrote on the origin and revival of Oyster Stouts. Oysters, being easily farmed from the sea during the 1700’s, was considered common pub grub being “as commonplace as peanuts today”. Porters and stouts were the common drink at the time, which began the bond of dark beers and oysters. Guinness even ran advertisements stating “Makes oysters come out of their shells”. The association of oysters and beer, specifically dark beers, continued until the decline of dark beers at the end of the 19th centery at the hands of the emerging pale ales. At that point, the combination of bivalve and beer stayed with society as a niche style.


Outside being an accompaniment to beer, it is theorized that oyster shells were originally used as a natural fining agent to filter the beer (similar to making a consomme broth). The first use of oysters as a brewing ingredient was credited to an unnamed New Zealand brewery in 1929. Several English brewers followed suit post WWI, where the oysters were added to the beer with the thought that it would provide additional nourishment to the malnourished populace (similar to the origin of the cream or milk stout). The trend continued until the 1960’s when the popularity of Oyster Stout again tapered off.

The contemporary revival of the Oyster Stout beer, according to Mr. Jackson, came from Bushy’s Pub on the Isle of Man in the mid 1980’s. Following the steps of earlier Isle of Man breweries from the 60's, Bushy’s Oyster Stout was developed and brewed using 5 or 6 whole oysters per barrel thrown into the brew kettle. The pattern continued with many other English breweries picked up the style and it slowly got some legs under it once more. Many so-called 'Oyster Stouts' emerged on the scene which contained no oyster in the beer at all. These brews were meant to be paired with oysters during a meal as opposed to using them as an ingredient. Marston's Oyster Stout became one of the stand out, sans-oyster Oyster Stouts in the English market.

On this side of the Atlantic, several small breweries and brewpubs carry the style as an on-and-off ‘specialty’ beer. Dogfish Head marketed a real Oyster Stout with oysters added to the kettle at flameout, although the beer has since been retired. The 21st Amendment in San Francisco continues to brew its Oyster Point Oyster Stout with real oysters added to the kettle. Rogue Ales, as part of their JLS limited series, brewed the Oyster Cloister Stout using Oregon harvested oysters, although getting your hands on any remaining bottles may be near impossible. Even Sam Adams has been rumored to have brewed an Oyster Stout for draft accounts sometime in 2009.

For those in the home brewing community, getting a good oyster stout will take you only as long as it takes to find a good recipe and brew it. While there are several recipes floating around the web, my choice would be to stick with one that comes from a reputable source. Otherwise, the endevor might be doomed from the start. A wise place to start might be the oyster stout recipe printed BYO Magazine's Mar/Apr 2005 issue (listed below for convenience).

Black Pearl Oyster Stout
(5 gallons/19 L, all-grain with bivalve mollusks)

OG = 1.052 FG = 1.013 IBU = 37 SRM = 60 ABV = 5.0%

Ingredients
9.0 lbs. (4.1 kg) 2-row pale malt
0.5 lb. (0.22 kg) flaked oats
1.0 lb. (0.45 kg) roasted barley
0.5 lb. (0.22 kg) chocolate malt
0.25 lb. (0.11 kg) black patent malt
10 oz. can raw oysters (and brine)
1 tsp. Irish moss
8.6 AAU Fuggles hops (60 mins)
(1.5 oz./43 g of 5.7% alpha acids)
4.3 AAU Fuggles hops (20 mins)
(0.75 oz./21 g of 5.7% alpha acids)
Wyeast 1084 (Irish Ale) or White Labs
WLP004 (Irish Ale) yeast
0.75 cups corn sugar (for priming)

Step-by-Step
Mash grains for 45 minutes at 152 °F (67 °C). Boil wort for 120 minutes. Add hops at times indicated. Add oysters and Irish moss with 15 minutes left. Cool wort. Transfer to fermenter, leaving oyster bits behind. (Don’t eat the oysters - they taste terrible.) Aerate, pitch yeast and ferment at 68 °F (20 °C).

Extract with grains Option
Replace 2-row pale malt with 14 oz. (0.40 kg) Briess Light dried malt extract, 3 lbs. 14 oz. (1.8 kg) Muntons Light liquid malt extract and 2.0 lbs. (0.91 kg) 2-row pale malt. In a 3 gallon (11 L) or larger stock pot, heat 1.6 gallons (6 L) of water to 163 °F (73 °C). Placed crushed grains and flaked oats in a large steeping bag and submerge bag in this hot water. Maintain temperature at 148–153 °F (64–67 °C) for 45 minutes. While grains mash, heat one gallon (3.8 L) of water to 170 °F (77 °C). Remove grain bag from steeping pot and place in colander over stock pot. Rinse grains with 0.75 gallons (2.8 L) of water from brewpot. Combine “grain tea” and dried malt extract with remaining hot water in brewpot and heat to a boil. Boil 60 minutes, adding hops at times remaining indicated in recipe. With 15 minutes left in the boil, add liquid malt extract, oysters and Irish moss. Stir thoroughly to dissolve extract. (Keep the clock running even though it will take a few minutes for the wort to resume boiling.) Cool wort and transfer to fermenter, leaving oyster bits behind. Add water to make 5 gallons (19 L). Aerate, pitch yeast and ferment at 68 °F (20 °C).


If you’ve had a decent oyster stout (either homebrew or commercial), let us know about your experience. What did you like or dislike? How would you change it?

Sláinte!

-JW

“Light beer is the invention of the Prince of Darkness”
-Inspector Morse (BBC)