The Ancient Art of Schlenkerla

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Schlenkerla are custodians of ancient technology reflective of what was in use ten thousand years ago. As ancient as the hallowed spontaneous fermentation methods of the Pajottenland Lambic brewers, Schlenkerla’s Rauchbiers receive significantly less coverage. Perhaps lacking the same mystique, their direct fired kiln malting is no less artisanal and is an ancient craft now practiced only by a tiny handful of breweries across the world, with Schlenkerla being the most renowned.

Allow us to take you back in time to the 23rd of July 1635 when King Charles I of England granted Sir Nicholas Halse of Cornwall a patent for a new type of kiln - a form of oven used to dry things, in our case germinated malts ready for brewing. This revolutionary new design completely changed a wide spectrum of industries by making it possible to kiln dry items without coming into contact with smoke from wood fuelled fires providing the drying heat. The result? It was now possible to kiln dry foodstuffs without the taint of smoke, a development much welcomed in the brewing industry. Critically it also solved the problem of wood scarcity being suffered in Britain at that time. Kilns could now be fired by any fuel, including coal, increasing efficiency and cutting costs enormously. It was now possible to scale production up enormously, bringing forth the advent of industrial malting and hop kilning, causing breweries across Britain to abandon their own maltings and oasthouses.

The ‘Information Age’ still several centuries away, it took generations for the technology to spread further afield and it wasn’t until the early 1800s that German brewers started to introduce the new technology. Eventually, as was experienced in Britain, German brewers started to wind down their own malting operations and large scale outsourced industrial production took precedence.

Schlenkerla Malt

That is except for one little outpost in Franconia - the picture postcard city of Bamberg. Fast forward to the 20th century and there were still four breweries stubbornly producing their malt the old way, each in their own individual maltings. Forward some more to the present day and only two continue to do so: Schlenkerla, and Brauerei Spezial. Both brewers being proud guardians of an ancient process used to create unique woodsmoke flavours from their own bespoke malts.

Matthias Trum is the 6th generation of his family to be at the helm of Schlenkerla and is deeply passionate about their commitment to this authentic method of malting.

Schlenkerla Matthias Trum

‘What industrial maltings do in one batch is our total annual production. Making it relatively crazy from an economic point of view. The entire kilning process is manual, we have conveyors now to move the grain, but it’s still a lot of effort. We could purchase malt cheaper but in respect of our family recipe and unique flavour profile, and of course a certain Franconian stubbornness, we stuck to the old technology, being one of the last in the world to do so.’

In their own kiln, heated directly by a fire fuelled by locally sourced beech logs of course, Schlenkerla produce around 350 tonnes of malt each year in 4 tonne batches, enough to meet their own needs. Their world renowned Märzen, Urbock, and Eiche, are all brewed with a grist of 100% Schlenkerla smoked malt. Only a small percentage of their malt is sourced externally for their Fastenbier and Kräusen beers that contain a blend of smoked and unsmoked malt, and their miraculous Helles lager comprised entirely of unsmoked malt (yet still with a smokey flavour, more on that later).

Schlenkerla Rauchbier Beech Logs

This could be a unique opportunity to explore the micro-terroir of the malts produced by Schlenkerla and Brauerei Spezial but, despite their friendly connection, they have never made the comparison between the malts they produce. Despite both being global specialists in the rauchbier style from the same small town there is a difference between the beers produced by the two breweries. Matthias speculates that Spezial don’t use 100% smoked malt, and this has led to a natural emergence of a difference in the styles produced. Some people in the town preferred their beer less smokey and drank Spezial; others, those with an affection for smoke flavour, preferred the Schlenkerla.

Although this unique style of malting allows for extremely close control of raw materials Matthias remains unconvinced of the potential for geographical terroir in barley, noting that the differences would likely be too subtle. On top of this it could potentially open them up to disruption in supply ‘We could partner with a single local farmer, but that’s risky. What if they have a bad season? With the oncoming creep of climate change, there have been years where Franconia was too dry to produce great malting barley’. He instead suggests that the more fascinating variable to explore is the variety of barley used:

‘The new varieties are bred to suit the needs of the farmers and industrial maltsters and brewers. Bred for high yields and low proteins. We always try to get the older varieties. Efficiency is lower, protein higher, but so much heartier in flavour. In Franconia a lot of breweries still focus on making this hearty dark beer, so it encourages a lot of farmers to grow these barley varieties around here.’

Given the overwhelming ‘bacon in a glass’ flavour associated with Schlenkerla’s beers, you could be forgiven that the primary goal of their maltings is to impart as much smoke flavour as possible into the malt, and final beer. However, Matthias assures that the focus is in remaining true to the historical methods of producing quality malt, the smoke being a welcome byproduct of that storied process.

Schlenkerla Maltings Kiln

‘Almost all other smoked beers on the market are working with industrial malt. I don’t know anyone who does it traditionally like us and Spezial do. We’re different from the Islay distilleries because they use peat to fire the kilns making the flavour totally different. The speciality of Bamberg is that we have continuously been doing it the old way. From a flavour point of view, our malt is smokier. But when I speak to colleagues they say it’s quite different. Sometimes when you open the bag of industrial smoked malt the smoke just disappears, and some have a tarry smoke flavour.’

Contrasting the Schlenkerla approach to the way ‘craft brewers’ use industrially produced smoked malts it is clear to see the goals are different. Typically modern brewers use extremely complex malt bills, with many different kinds of grain and malt to achieve a final flavour. If the target is a smokey flavour, often the quantity needed is quite low, typically 10-20% of the total grist. Matthias posits that this is a bit like the way flavourings are more widely available to us in modern cooking:

‘If you look at Weyermann [industrial malt merchants] they have 100s of different malts, which you can use to build all kinds of different flavours. That didn’t exist 100 or even 50 years ago. There was brown malt, pale malt, maybe roast barley for the stouts and that was it, you work with that. It’s similar to what you have in modern kitchens. When people don’t know how to cook any more you have all these kinds of ready made ingredients, or little bags of something you can add to get a special flavour.’

Matthias concedes that this doesn’t necessarily mean ‘craft brewers’ don’t know what they’re doing. It’s more a case of technology advancing, and leaving behind some more traditional, arguably less efficient ways of achieving deeper flavours. For example, there’s now a specialty malt available that can be used to replicate the effects of decoction mashing, a technique used by many German brewers (including Schlenkerla) that is essential to the crisp, dry maltiness of many lager styles. It is, however, extremely inefficient requiring parts of the mash to be drawn off and boiled - a process most modern brewhouses are simply not equipped to do.

Alas, not everyone has the benefit of working on the same mash tun as their Great Great Grandfather. Although this comes with its own disadvantages. Matthias has already begun the arduous process of sourcing a replacement direct fired kettle, despite not needing it for another ten years or so simply because it may take that long to find, or even teach, someone to replace it.

‘What distinguishes us from everybody else out there is the drive or addiction to old ways. We go to great lengths to keep the old techniques alive, particularly where it has an impact on flavour. We have a truck not a horse and cart because that doesn’t affect flavour. We do have computer systems integrated into our Brewhouse that control valves and pumps but at the core it’s always the original production method and vessels. That’s something a modern company cannot copy, the technology is not available to buy anymore, it doesn’t scale and the knowledge isn’t available.’

While discussing the benefit of that knowledge from the past, Matthias was able to quickly lay hands on a truly incredible document. A little unassuming journal, his Great Great Grandfather’s brewing diary from 1840-1852. In the book his ancestor had detailed everything about the daily operations of the brewery, recipes, and a log for every batch of beer in the ornate cursive script of the time. After having it professionally transcribed to a more usable modern format Matthias was able to benefit enormously from it’s contents.

Schlenkerla Brewing Journal

In the period covered by the journal the brewers of Bamberg were famed for their bock beers due to their high strength. However, also detailed in the journal was the recipe and method for making a second, low alcohol, beer from the spent grains of the bock mash. Intrigued, Matthias followed the recipe and methods -- easier to do when the vessels are exactly the same -- ending up with a beer a little over 1% but full of character and body unexpected of such a low ABV.

This ‘Hansla’ or Heinzlein was at the time the everyday beverage for children, workers, anyone who needed a clear head whilst going about their day. This market still exists today (children excluded of course) and Schlenkerla have released their Hansla commercially again for the first time since the 19th century. The only concession to the modern age being it’s ABV toned down to 0.9% to fit under German Low Alcohol regulations. ‘If we wanted to go alcohol free we’d need to stop the fermentation at 0.5% and pasteurise it, theoretically possible, but I don’t like to pasteurise as it changes the flavour.'

Schlenkerla Hansla

Having such detailed records from the past allows for a more accurate presentation of anecdotes from the brewery history often obscured by marketing speak over the years. Matthias is able to detail the origin story of their Helles; the fascinating expression of smokey flavour, despite there being absolutely no smoked ingredients in it (I told you we’d come back to this).

The local brewing industry was in complete and total disarray as a result of the First World War. Drinkers were out on the front, brewers were out on the front, the owners were too, and many of them didn’t return. In the interwar period, during hyperinflation, as many as two thirds of Bamberg’s breweries closed their doors forever. However, as one of the few surviving breweries, Schlenkerla (at that time under the stewardship of Matthias’ Great Grandfather) were offered a contract by the local train station for their canteens. They wanted the famous Smokebeer but also a more ‘ordinary’ Helles. This being the early 20th century the brewery had only one yeast strain, and the portion used taken from the Rauchbier fermentation carries over a delicate waft of the famous Schlenkerla smoke. Word of this beer quickly spread by the railworks craftsmen and soon became the beer of choice in the lunchboxes of the City’s artisans.

Schlenkerla Helles

The great tragedy is that it’s not really possible to import the best dispense method for Schlenkerla beers. Fresh, live beer, filled into Oak casks, as served (almost) exclusively at their Tavern in Bamberg. This serving method is truly sensational, with the softer carbonation allowing some of the beer’s subtleties to shine through a little more than in the bottle. We’ve been fortunate, and trusted, enough to bring the occasional barrel across for special events. It provides immense pleasure to observe a bar full of happy people each with a pint of beautiful black liquid topped with a craggy mountain of whipped white foam as the cask empties in mere hours.

Finally, after pondering where Schlenkerla sit amongst today’s modern brewing scene Matthias sums it up neatly:

‘We’re a little bit in both worlds, we’re this extremely traditional boring brewery. I’m probably a boring person as I’m not hip and modern and I can, and will, talk a lot about history. But I think that the historic approach we’re doing has become cool again. Like some kind of heavy metal unicorn, a weird fusion.’