In the middle of the old part of Bamberg, directly beneath the mighty cathedral, one will find the historic smoked beer brewery Schlenkerla. First mentioned as "House of the blue lion" in 1405, Schlenkerla today is run by the 6th generation of the Trum family and is the fountain of Original Schlenkerla Smokebeer (in German, it's called "Aecht Schlenkerla Rauchbier"). The smoked beer is here at the brewery tavern still being tapped directly from the wooden barrel according to old tradition.
Schlenkerla loves sticking to age-old traditions. In fact, the smoked beer they brew is still tapped from oak-wood kegs. How cool is that?
"Even if the brew tastes somewhat strange at the first swallow, do not stop, because soon you will realize that your thirst will not decrease and your pleasure will visibly increase."
History of smoked beer
Smoked malt and smoked beer have been around at least for 5,000 years, and in Central Europe presumably all beers had smoky flavor. When drinking an Aecht Schlenkerla Rauchbier, one has in effect a piece of beer history with every swallow!
There are two different methods for drying germinated grain: air drying and fire drying (air malt and kiln malt). With fire drying, it was unavoidable that the smoke from the fire penetrated the malt and gave it a smoky aroma. Presumably, fire kilns have been around since the Bronze Age some 5,000 years ago. In moist climates, e.g. in Central Europe, the fire kiln often was the only feasible way to dry the grain sufficiently. Such a fire kiln and some smoked barely grains were found in the grave of a Celtic chieftain from around 550 B.C. in Hochdorf, Germany. Furthermore, in such climates it was essential for survival in winter that grain did not get moist. Therefore, the storage compartments in houses were connected to fireplaces in order to keep away moisture and also mold. As a side effect, the smoke probably ensured that rodents did not spoil the grain. Last but not least, cooking was also done with an open fire, and so smoky flavor was present in all foods and of course also in beer.
For thousands of years, brewing technology had not changed considerably. But then in the course of the industrial revolution in England, brewing (as all crafts) underwent enormous changes. Suddenly it was possible to produce smoke free malt in any climate and with any fuel! The latter fact made this new production method much more cost effective than the traditional smoke kilns; for the smoke kilns, high grade wood and good smoke aroma were (and still are) important. Subsequently, more patents on further improved kilns were issued. And since the new technique was cheaper and less of a fire hazard, it soon replaced the old smoke kilns in England. Since England led the rest of the world with industrialization, it took more than 150 years for the invention to make its way to Germany.
As in England, also in Germany, the new cheaper technology soon replaced the old expensive one; and by 1900 almost all smoke kilns had vanished. All? No, in Bamberg at the beginning of the 20th century, there still were four breweries that made smoked malt: Brewery Polarbär (closed in WWII); brewery Greifenklau (closed its malting operation in the 1970s); brewery Spezial, and of course Schlenkerla. And the latter two have - as the only breweries in the world - preserved the old tradition of fire kilns continuously until today.
Due to the craft beer revolution over the past years, old beer styles have become popular again. Since the big commercial malting companies have begun industrial production of specialty malts, today one can find a number of new smoky beers made with industrially produced smoke-flavored malts. The old production technique with a brewery-owned open fire kiln has however been preserved until today only by Spezial and Schlenkerla in Bamberg; thus this unique beer style is often referred to as “Bamberg Smoked Beer,“ or, in German, "Bamberger Rauchbier".
Around 1800, Georg Sedlmayr the Elder from the Spaten brewery (Munich, Bavaria) was one of the first brewers who switched from the old “Bavarian kiln“ (a smoke kiln) to the modern “English kiln“ (a kiln without smoke). By the way, his son Georg Sedlmayr the Younger was the one who made the spectacular espionage trip to England in the 1830s to bring back important beer technology improvements to Munich, thus laying the basis for today’s worldwide reputation of Bavarian beer (and also indirectly for Pilsener style and all lager beers).
It is not possible to brew beer directly from barely; first it has to be processed into malt. This happens in the Schlenkerla Brewery's own malthouse.
1st Step: Steeping
First the barley has to be soaked in water in order to start the germination process. In the language of brewers this is called "steeping". During this process, the grain is alternately steeped and aerated.
2nd Step: Germination
After the water content in the grain has reached 35%, it starts to germinate. When the grain begins to grow, enzymes are formed, which are able to break down the contents of the grain (mainly protein and starch). This ability is necessary later on in the brewing process. During the 7-day germination period the green malt, as brewers call it, is constantly turned and aerated.
3rd Step: Kilning
In order to stop germination and to stabilize the involved biochemical processes, the green malt must be dried (kilned). That is where the secret of the Original Schlenkerla Smokebeer lies. A beechwood log fire underneath the kiln heats the air, and the smoke gives the malt its typical smoky flavor.
This traditional way of making smoked malt is nowadays only done by two breweries in the world: Schlenkerla and Spezial of Bamberg.
4th Step: Grinding
To continue the transformation process started in the malthouse, the malt must initially be ground into grist.
5th Step: Mashing
The grist is mixed with water in the mash tun. In the resulting mash, the enzymes can convert the components of the malt. The most important step is the transformation of starch into malt sugars. This takes place at temperatures between 45°C and 77°C.
A specialty at Schlenkerla: The mash is still prepared in the ancient decoction technique in which the mash is additionally boiled. This results in a richer and fuller flavor of the smoked beer. Decoction comes from a time when thermometers had not been invented yet and temperature adjustment was done indirectly through volume measurement (mash drawing with buckets). As this technique is more labor and time intensive than modern mashing forms it is nowadays seldomly used in breweries.
6th Step: Wort Separation (Lautering)
After the conversion process is finished, the sugar-rich malt liquid, the wort, is separated from the solid components, the spent grain. The wort is then transferred to the brew kettle, while the spent grain is removed from the brewery, and can be used, for example, for baking bread.
7th Step: Boiling
The wort is boiled in the kettle and the hops are added in several stages. Through the heat the bittering elements in the hops are released, giving the beer its distinctive bitterness. During the boil, water evaporates so that the wort reaches the necessary concentration (original gravity). Some components of the wort become insoluble through the heat; these substances are called the "hot break" and must be removed subsequently. The overall process in the brewhouse from mashing to the completion of the boil takes about 8 hours.
8th Step: Cooling and Pitching
After boiling, the wort is pumped into the whirlpool; the wort is "drawn off", as brewers say. Here the hot break is removed. Subsequently the wort is cooled, aerated and yeast is added; in the language of brewers, it is "pitched".
9th Step: Primary Fermentation
Yeast can survive not only through aerobic respiration (with oxygen, as the human body), but also in an anaerobic (without oxygen) environment through alcoholic fermentation. In this process, malt sugar is converted into alcohol, carbon dioxide and heat. At the end of primary fermentation, which lasts approximately 7 days, most of the yeast settles to the bottom of the fermenting tank. For this reason, it is called bottom-fermented beer. The yeast in top-fermented beer, i.e. Original Schlenkerla Smokebeer - Wheat, rises to the top of the fermenting tank. The green beer - which is what this interim product is called by franconian brewers - is now pumped to the lagering cellar for secondary fermentation.
10th Step: Secondary Fermentation and Maturation
Now follows a period of maturation to perfect the beer. The remaining fermentable elements in the green beer are transformed by the yeast, whereby more carbon dioxide is created. The conditioning/storage tanks are closed with a prime regulator (a pressure release valve) which is set to a specific counter-pressure. In this way the carbon dioxide content in the final beer is regulated. Maturation takes about 6-8 weeks, after which the beer is ready to drink.
Another specialty of Schlenkerla:
The maturation takes place in the old caves underneath Stefansberg, which are part of an extensive tunnel system over 700 years of age. As they have a constant low temperature throughout the year, they have been used by brewers for centuries. Ice was harvested from lakes and rivers, to cool down the caves further and after warm winters, when not enough ice was available, it was even imported from as far as Finnland and Sweden to mature Smokebeer properly. Original Schlenkerla Smokebeer -Wheat does not mature in the lagering cellar, but in the bottle (Original Bottle Conditioning).
11th Step: Filtration
At the end of secondary fermentation, the beer still contains yeast and other suspended matter. It must be filtered in order to give it the brilliant clarity desired by the consumer. After that, it can be filled into either kegs or bottles.
Bottling and racking
Kegs and barrels:
After thorough cleaning and inspection, the kegs are filled under counter-pressure. Through pre-pressurization the beer flows into the keg without foam.
Another specialty at Schlenkerla:
following old tradition, the Smoked Beer in the Schlenkerla Brewery Tavern is still tapped exclusively from oak-wood kegs.
As with the kegs, the bottles are filled under counterpressure. Subsequently the bottles are labeled and packaged.