Tag Archives: cologne

Beer Styles, Recipes

How to Brew Historic Kölsch from 1927

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Johannes Olberg’s book “Moderne Braumethoden” from 1927 contains a multitude of recipes for more than 50 different beer styles. One of them is Kölsch, briefly discussed as the “national drink” of Cologne, and characterised as golden, thirst-quenching, “not too heavy but digestible” beer. The recipe is particularly interesting because it’s the only well-documented Kölsch recipe I’m aware of from before the end of World War 2.

A lot has changed since then, and the Kölsch of 2024 is of course very different from Kölsch about 100 years earlier. Even the modern standards of what Kölsch is supposed to be, the “Kölsch-Konvention”, was only developed from 1981 onwards, Germany’s Federal Cartel Office signed off on in it 1985, and it was finally signed by 24 Kölsch breweries in 1986.

Olberg’s recipe doesn’t mention a specific malt to use, but judging from the colour description, we can assume that a pale malt like Pilsner malt was used.

A number of mashing methods were used, like Kesselmaische, or boiling one or two thick decoctions, but the following process was described more in detail:

The crushed malt is mashed in with brewing water to get to a temperature of 35°C, then rested for 30 minutes. After that time, the mash is slowly heated up to 50°C over the course of an hour (that’s 0.25°C per minute), and then to 70°C over the course of another hour (0.33°C per minute). It shall then rest at this temperature until the mash is fully converted. The author suggests that this would take 30 to 40 minutes and that an iodine test should be used to ensure full saccharification.

After that, the temperature shall be increased to the mash-out temperature of 76°C, either by heating up the mash, or by moving one third of the mash into the lauter tun and boiling two thirds of the mash in the kettle, then mixing it back into the mash to increase the temperature to 76°C (the two thirds doesn’t sound right, I’d reverse the ratios).

When the mash is in the lauter tun, lautering begins. About 6 to 8% of the total amount of hops are reserved for later, and of the remaining hops, a third is added to the first runnings. The wort boils for a total of 120 minutes.

Another third of the hops is added after an hour of boiling, and the last third is added 40 minutes before knock-out. The 6 to 8% of hops reserved earlier are added to the wort shortly before knock-out. The hopping rate is about 30.9g of hops per kg of malt that is mashed in.

The resulting wort should have an original gravity of 11 to 12°P.

The wort is then chilled to 10°C and the Kölsch yeast is pitched. Fermentation should last about 5 days. After fermentation is finished, it is then pumped over into maturation casks which are only loosely bunged. After 5 to 6 weeks the beer can get filtered and sent out to customers.

The maturation casks are also prepared before the young beer is pumped in: hops (at a rate of about 0.9 g/l) are put in 75°C hot water for about 30 minutes, then the steeping water and the hops are added to the casks.

Using all this information, I came up with the following recipe to brew about 20 liters of this historic Kölsch:

  • 4.9kg Pilsner malt
  • 150g hops, ideally a traditional low-alpha-acid German variety with a fine aroma, the finer the better. For my recipe, I assumed Hersbrucker with 3% alpha acid, but Spalter, Hallertauer mittelfrüh or Tettnanger would be equally suitable.
  • German Kölsch yeast, e.g. WLP029

Mash in with 14 liters of water, then proceed with mashing and lautering as described above. The hop additions are:

  • 46g hops in first runnings
  • 46g hops 60 minutes before end of boil
  • 46g hops 40-x minutes before end of boil

After the end of the boil, whirlpool, then knock-out. Take the time between end of boil and knock-out into consideration for the last hop addition (it’s basically the x in the last hop addition). Shortly before knock-out, add 12g of hops to the wort.

Chill the wort to 10°C, then pitch the Kölsch yeast. Wait until fermentation is finished, then add 18g hops to a small amount of water and keep it at a temperature of 75°C for 30 minutes. Depending on whether you move the young beer into a separate vessel for maturation or not, either add the hops-water mixture into the maturation vessel before you pump in the beer, or simply add it to the fermenters. Mature the beer for 5 to 6 weeks, then carbonate, filter (if you have the facilities, most homebrewers don’t) and package it.

The resulting beer should have about 12°P. If you’re using hops with 3% alpha acid, the final beer should have about 44 IBU (calculated).

In terms of bitterness, this is a very different beer from modern Kölsch. And not only is it quite bitter, it is also kind of dry-hopped. The difference is that the hops were briefly treated with hot water at 75°C, which should denature the natural amylase enzymes in the hops which could cause hop creep, but is still not quite hot enough to cause the alpha acid to be isomerised and introduce even more bitterness in the beer.

So, if you want to rebrew a hundred year old historic Kölsch, this recipe is a good place to start.

History

The Struggle Between Top- And Bottom-Fermented Beer In Cologne

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This was supposed to be an article about Wiess, the legendary white beer predecessor of Kölsch. In a discussion with my friend Ben a few months ago we came to the topic of how little is actually known about Wiess and its history. So I tried my hands at researching it, and couldn’t really find anything through my usual sources. My next step was to go the Schultze-Bernd library at VLB Berlin, a vast collection of historic material about beer and brewing, curated by Gesellschaft für Geschichte des Brauwesens (GGB; lit. “Society for the History of Brewing”). I got to talk with their librarian, and she told me that she had done some research herself, but wasn’t really able to find much. I nevertheless tried to see what I could find. I didn’t find out much, either, but instead, I was able to dig up some interesting details about the history of brewing in Cologne during the 19th and early 20th century, including the struggle between top- and bottom-fermented beers in the city.

When the guilds were disbanded in Cologne in 1798 and the occupying French introduced freedom of trade, breweries in the city started exploding, from 52 in 1794 to 128 breweries in 1828. The city also grew massively, and the conflict from before the freedom of trade of outside brewers trying to sell their beer in Cologne was less noticeable as the demand in beer increased massively, as well. And while outside breweries were seen as a nuisance in the 1830s, they were of little significance: in 1839, only 2190 hl of Bavarian beer were imported into the city, from places like Bamberg, Kulmbach and Würzburg.

The first attempt of brewing bottom-fermented beer in Cologne was conducted in 1831 by a Bavarian Jewish brewer named Rothschild. The brewery failed, though, and was turned into a sugar factory only 6 years later. The second bottom-fermenting brewery was owned by a brewer called Ehemann, and formed the foundation for the later Adler brewery. In total, bottom-fermenting only grew slowly in these times, with two breweries in 1850, and four in 1869.

A major issue for them was to build reliably cool lagering cellars. Already the top-fermenting breweries had similar issues. To keep the cool air somewhat in, beer cellars were only opened during the night. Some of the beer still got sour. When it was an early stage of souring, it actually was a popular drink, and got sold under the name Steckenalt. Beer that got too sour was unrecoverable, and sometimes had to be poured out, causing substantial losses to some brewers.

Proper ice cellars only started being built in the 1850s, and in winters with very little ice, ice was brought to Cologne from as far as Norway.

From 1870 to 1900, the beer market was consolidated, and the number of breweries fell from 135 to just 68. This was due to technological improvements in beer brewing, giving an advantage to the more mechanized and automated breweries and those who could produce their own ice through the use of artificial refrigeration. Bottom-fermented beers were so successful that even some of the largest top-fermenting breweries in Cologne switched to bottom-fermentation. For some time it looked like top fermentation in Cologne was doomed.

Interestingly, the smaller brewers managed to overcome their crisis by introducing some automation and refrigeration on a smaller scale, while the growth of bottom fermentation stopped around 1900, and large breweries now faced the issue that their breweries were oversized for the production amounts, causing increased production costs.

This actually gave the small top-fermenting breweries a slight advantage: they managed to slightly cool their cellars by putting ice in containers hanging down from the ceiling, producing the perfect conditions to store top-fermented beers. Through that, they got rid of much of the dangers of beer spoilage, could brew weaker beers even during the summer (that otherwise would have spoilt), had a shorter turnaround time on their beers (virtually no lagering), and were able to achieve a more consistent quality.

Beer taxation was reformed in the early 20th century, and that had some impact on brewing in Cologne as well: the brewing tax law of 1906 introduced consistent beer taxation for all of North Germany. It contained some provisions that were helpful to the small breweries of Cologne, in particular a progressive tax based on the amount of malt used by the brewery. The law also introduced a prohibition of “malt surrogates” (such as unmalted grains, sugar or other starch sources) for bottom-fermented beers. Suddenly, the large bottom-fermenting breweries couldn’t use some of their classic ingredients like rice, maize and sugar, which at the time were cheaper than malted barley. One local beer type in particular, Knuppbier, a bottom-fermented beer sweetened with sugar, couldn’t be brewed the same way and had to be switched to top fermentation, so some of the breweries had to set up separate top-fermenting brewing departments just for that beer type.

World War I changed everything again and brewing ingredients were strictly rationed. The malt surrogate prohibition for bottom-fermented beers was still in effect, while for top-fermented beers, artificial sweeteners, food colouring and non-beer-derived CO2 for carbonation were allowed. The restrictions were tightened several times which made brewing even weak beers entirely unprofitable, so several small breweries ceased operations.

The detrimental effect on top fermentation in Cologne was noticeable after the war: while in 1913, 41% of all the beer brewed in Cologne was still top-fermented, that share had dropped to just 6.7% in 1922. Of 53 top-fermenting breweries before the war, 29 had shut down after the war, while 4 had switched to bottom fermentation. The main reason why not more of these small breweries folded was often the direct connection of the brewery with a brewery tap, a pub of sorts that only sold that brewery’s beer as well as food, of course with the idea that people would drink even more if they had something to eat with it. These pubs were often set up to look rustic, which combined as their status as small Hausbrauerei gave it a certain charm that attracted the people of Cologne.

Of course, credit where credit is due: this article is mostly based on the PhD thesis of Hans Trinius at the University of Cologne, written in 1924. Not only does it give quite detailed insight into the brewing industry and its ups and downs from the 19th century up to ~1922 (it also contains lots and lots of statistics related to production, import&export, taxation, etc.), it also very obviously influenced a number of other books and publication surrounding the topic of beer and Cologne.