Finally, we have seen the back of winter (fingers crossed). Daffodils have flowered, blossom has bloomed and most of us are getting up when it’s light and getting home from work in time to crack open a beer in the garden. Thoughts of the average beer lover turn away from the heavy brews; warming imperial stouts are placed at the back of the cupboard, barley wines are stuffed into their hiding places until their restorative qualities are needed again. It’s time for warm weather beer – light, refreshing and quaffable.
One such beer is Kölsch, the famous beer of Cologne (Köln), Germany’s fourth largest city, situated in North Rhine Westphalia. Kölsch is a very specific beer style – in 1985 the Köln Brewery Association prepared the Kölsch Konvention, that was then published in the Bundesanzeiger and stipulates that Kölsch can only be called so if meets the following criteria: - it is brewed in the Cologne metropolitan area, it is pale in colour, it is a ‘Vollbier’ (a German beer tax category beer with a starting gravity of between 11 and 14 Plato), it is hop accented and it is also filtered. In 1997 the beer style received protected designation of origin status from the EU, meaning it is now afforded the same protection as our beloved Cornish Pasty. Craft breweries wishing to emulate this crisp, snappy and refreshing brew circumvent this legislation by naming their beers ‘Kölsch style’ or ‘Köln style’. And examples are growing in number; Goose Island Summertime, Ballast Point Yellow Tail, Harpoon Summer Beer and our utterly marvellous Tzara. One common thread unites these Kölsch style beers – an attempt to stay true to the basic principles of Kölsch brewing.
Kölsch beers are sometimes mistaken for light lagers because of their straw blond colour. They are, however, distinguished by their very subtle but noticeably fruity flavours. It is light in both body and appearance, its maltiness is subdued; its hoppiness is assertive but unobtrusive. This is a beer designed to be drunk all day every day!
So what goes into a Kölsch then? Well, for starters, consider the malt bill. Mostly Pilsner malt and Wheat malt (between 5-10%). We got ours from our favourite German Maltster, Bamberger, adding a dash of Carapils from Weyermann. Pale Ale malt and Torrefied Wheat do not make the cut with Kölsch. Hops must also be classically German – traditionally, Perle or Spalter Select are used for bitterness (we went with Perle), Tettnanger and/or Hallertau Tradition added at the end of boil for aroma. Our Rolec Hopnik is filled with the same amount of hops as a brew of Kipling with a combination of both. The nature of these noble hops used will not overpower the essence of the brew. Our liquor needs to be soft so we get that distinctive smooth mouthfeel – luckily Bakewell water comes off the millstone grit of the Peaks, so is, thankfully, lovely and soft (also allowing us a blank canvas for other beers that need harder liquor). And most importantly of all - the yeast strain. This must be a classic Kölsch strain, or you may as well give up and brew something else. As Matthew, one of our brewers likes to say, we have the skills to pay the bills, so we obtain a Kölsch strain from our good friends at White Labs, San Diego and propagate it to an ideal pitching rate via various flasks and finally our yeast propagation vessel. So our ingredients are indeed simple but of the absolute highest quality. But that is not all that is required for the perfect brew of Kölsch…
Look in many English and American brewing texts and you will see Kölsch referred to incorrectly as an ‘Ale’. It does ferment at near Ale temperatures, but one has to consider how the Germans themselves classify Kölsch – ‘Obergäriges Lagerbier’ – top-fermenting lager beer. Calling all top-fermenting beers ‘Ales’ is simply misusing the name. To the Germans, Ale is a British thing and doesn’t ever get mentioned in the same breath as Kölsch. What is now needed is a few weeks of lagering at 4˚C, slowly moving down to -1˚C, to round out those fruity flavours from the Kölsch yeast strain. Having nothing in the way of spare capacity and a completely full production schedule doesn’t stop us from completing this lagering period fully – it is essential for a perfect Kölsch. Thankfully our bosses understand, primarily because they like good beer too.
After fermentation and lagering, the other key difference now occurs between a true Kölsch and Tzara, our Köln-style beer. We don’t have a filter, so instead we use our centrifuge to clarify the beer. A true Kölsch is always filtered, but centrifuging allows us to clarify the beer without stealing those delicate flavours we put into the beer in the first place.
Brewing Kölsch-style beer ourselves guarantees we can appreciate the Kölsch style at its best. We do everything we possibly can to keep oxygen away from the beer after primary fermentation. Dissolved oxygen can produce off-flavours, ruining the delicate taste for which Kölsch is known. We keep levels typically below 10 µg/l (something we do for all our beers). It is a style which has no strong flavours to hide behind; no massive hop pungency, no crystal malt sweetness, no boozy alcohol. Brewing excellence is thus required throughout the whole process. It is a massive challenge to get it just right; we bloody love making Tzara and hopefully you enjoy drinking it as much as we like brewing it.