Brewing Kölsch-Style Beer

Brewing Kölsch

Remember that when brewing this beer, unless you live in Cologne, Germany, you are not brewing a Kölsch! The term is a legally protected name. On Canada Day in 2003 I was brewing one, and coined the term Kölsch-eh to refer to this style of beer brewed in Canada. I hope you'll do the same.

General

Remember when brewing a Kölschy that this is an extremely delicate beer in which a fine balance is maintained. There is not single characteristic which should dominate : hops, malt and yeast are all present, but all in just the subtlest amounts. Whenever I use the term 'aggressive' or 'assertive' in reference to a Kölsch or Kölschy, it is a relative term and should be considered similar to 'tall' as seen by a dwarf, or 'short' as seen by an NBA basketball star. 'Agressive hopping' for a Kölsch would for example be nowhere near a potent IPA which can approach 45 or 50 IBUs. It would not even be as strong as a good stiff Northern German Pilsener in the 35 to 40 range. A nice gentle 25 IBUs is "aggressive" for this style. Similarly, "assertive" yeast would be something not particularly aley, but still on the very high end of acceptable for this beer.

Grainbill

The vast majority of Kölsches today use only 100% Pilsener malt, and I know of at least two breweries which use malts from Weissheimer, which are available in better homebrew shops on this side of the pond. I find that Canada Malting 2 Row does an exceptional job. A couple or three (only 1 confirmed, actually) reportedly still use about 10% malted wheat in their grain bill, and one lonely Kölsch is really the odd one out and puts 10% Munich malt in the grist. But this is really an exception, and in fact this brewery is not a signatory of the Kölsch Konvention if that matters. The Konvention still technically applies to everyone, whether a signatory or not, so technically 10% Munich malt is acceptable in a Kölsch. I wouldn't recommend it, though.

Personally I always brew my Kölschy with a bit of malted wheat, but that is a matter of personal preference as I brew all of my beers with a bit of malted wheat (about 15% of the grist) for head retention. Flaked wheat and other adjuncts are not welcome in this style.

Hops

Of course you will use only good German hops for a beer that is true-to-style. I have confirmation of Hallertauer, Tettnanger, Hersbrucker and Spalt used in various brands, and have it on good authority that Czech Saaz is used as well. The odd brewery does use Nothern Brewer for bittering but this seems to be the exception. Do not even consider non-German Tettnanger because it is not the same thing. Both in North America as well as in Australia it is fairly well documented that their original "Tettnanger" hops were actually mislabeled, and are probably really an offspring of British Fuggles. The BCJP states that Kölsch has a range from 16 to 30 IBUs, but by my taste buds that is too far on both ends and I'd put the 20 or so I've tasted within the range of about 19 to 26.

After trying real German Tettnanger I have become a huge fan of them, and use them almost exclusively (when possible) in my Kölschy beers.

As for aroma hops, there are 3 or 4 of the 20 or so I've tasted which do have a distinct late-hopping, although a couple of brewmasters I spoke with told me that aroma hops are strictly 'verboten'. The Kölsch Konvention states that Kölsch is "hopfen betont" which means "hop accentuated", but it does not specify whether that should be bittering, flavour or aroma hops, so I guess technically speaking all three are perfectly valid in your Kölschy. Two of the most assertively aroma-hopped Kölsches I've tasted are Mühlen-Kölsch, and the famous Päffgen. Both exhibit considerably more hop aroma than most of their brethren, and both probably even cross the border and are no longer even 'subtle'. They are the exceptions, but both exceptional brews!

Yeast

Yeast character in the brands I've tasted varies quite considerably. In about 1/3 of them there is little if any noticable yeast character present. Most, however, do have pleasant but subtle fruity aromas with apple, pear, a few cherry like Peters, and even the odd more exotic notes. One or two have quite strongly flavoured (for a Kölsch) yeasts, and on tap at least Gaffel had considerably Ale flavour to it.

Most Kölsches are brewed with an extremely attenuative yeast at 75% to 85%. One or two like Dom have a fair bit of residual sweetness to them which suggests either a slightly higher mash temperature, or a less attenuative yeast, or both. Since I was last there Dom is now brewed under contract by nearby Küppers, so I am not sure if it still tastes the same. The Kölsch yeast sold by White labs is without question from Cologne, and I have it on good authority that it is in fact from PJ Früh

Mash

The vast majority of Kölsches are highly attenuated, which is accomplished both by the yeast as well as by a low mash temperature. Mash low and long for this style. A very common schedule is to do a very short 10 minute protein rest at 52C/126F, then boost to a low sugar rest at 62C/144F for 30 to 40 minutes, and finally boost to 72C/161F for another 30 to 40 minutes, and last but not least mashout.

I simplify things with a long 75 to 85 minute sugar rest at 149F to 151F, and finally mashout.

Fermentation

The norm is that a Kölsch gets fermented at 18C to 20C for 5 to 8 days, then gets reduced to a 1C lager temperature for 3 to 5 weeks.

Filtration

All Kölsches are filtered, period. In most cases the beer is centrifuged, then passed through 2 different types of filters. One brewery told me they are the only ones who do not centrifuge, and I know that several others use only one type of filter or the other. Most use all 3 technologies.

On a homebrew scale I never do this. I violate the Reinheitsgebot and add finings to my Kölschy to help it clear more quickly, and I find that after a month of lagering it is crystal clear.