Brewing a Lighter Kölsch

Posted by Ryan Speyrer on Jun 25th 2019

Kölsch is a beer style perfect for the Summer. Clean and crisp often exhibiting subtle pomme fruit notes, the style can easily be mistaken for a German or Czech style Pilsner. Originating in the German city of Cologne (referred to as Köln in German), this beer style is often referred to as a hybrid between Ales and Lagers on account of its fermentation regimen. Kölsch is fermented with a German ale yeast, typically somewhere between 56-64F. The green beer is then lagered for up to four weeks to allow the yeast to continue conditioning the beer, cleaning up fermentation by-products and producing a crisp, clean beer lying somewhere between a fruity ale and a clean, crisp lager.

I've made several brews in pursuit of the perfect Kölsch over the years and recently I decided to go a slightly different direction and attempt to meld the concept of an american lager and a Kölsch. By this I mean take the clean profile of a Kölsch and lighten the body and flavor by using adjunct sugars. I was in the mood to make something purely intended to slake my thirst during the sweltering Louisiana summer.

A Typical Kölsch is brewed with 100% Continental Pilsner-type malt. Some recipes make allowances for a small percentage of pale wheat malt to enhance body and head retention, but I have never found this to make a product that resembles the real thing. A grain bill consisting of 100% Pale malt and perhaps acidulated malt for pH adjustment should be all you need for a classic base recipe.

To lighten the body beyond what is typical for a Kölsch, there are many options:

Rice Solids or Flaked Rice - Lightens body and adds a distinct, smooth rice flavor that is reminiscent of Sake at sufficiently high levels.

Flaked Maize - Lightens body and adds a smooth, sweet character. At higher levels can exhibit a sweet corn note.

Dextrose - Also known as Corn Sugar, this adjunct is fully fermentable so it will boost alcohol and lighten the body of your beer.

Brewers Crystals - This adjunct is a blend of sugars that replicates the sugar composition of wort without any of the maillard products found in malt. Brewers crystals are 80% fermentable.

For my recipe, I substituted a portion of the grain in the mash with Brewers Crystals, which were added in the kettle to lighten the flavor and body of the final beer. I also used Rahr 2-row malt instead of a continental Pilsner-style malt, which would have been more traditional. This choice is consonant with creating a clean, crushable beer that does not have any overly assertive malt flavors. The recipe I used is shown below:

Speyrer Crushable Kölsch

Batch size: 1 barrel (31 gallons)

Mash Temperature: 152F

OG: 1.043

FG: 1.004

Grain Bill

Rahr 2-Row Malt - 50 lbs

Weyermann Acidulated Malt -10oz *pH adjustment

Rice Hulls - 1 lb *lautering aid

Kettle Additions (60 minute boil)

3 lbs Brewers Crystals 60 minutes

0.2oz Sterling pellet hops (10.2%AA) 60 minutes

1.5oz Saaz pellet hops (2.8%AA) 30 minutes

Yeast nutrient and Kettle Finings - 15min

Yeast

Omega Yeast Labs Kölsch II (OYL-044)

Directions:

Perform a single-infusion mash with 19 gallons of strike water to reach a mash temperature of 152F. Mash pH was 5.38 for my batch. Vorlauf for 45 minutes then transfer runnings to kettle while sparging with 28 gallons of water. My pre-boil volume was 38 gallons with a pre-boil gravity of 1.039.

Boil for one hour adding the kettle additions as directed. After my boil was done, I had 34.9 gallons of wort with a post-boil gravity of 1.048, which was higher than my intended target. I added water to the kettle to bring the wort to the target gravity of 1.043. If a stronger final beer is desired, skip the dilution step and just roll with whatever post-boil gravity you get.

The wort was chilled, transferred to the fermentor, and well oxygenated. The fermentor was set to 65F and the OYL-044 yeast pitched into the tank. Fermentation kicked off rapidly and the beer reached a terminal gravity of 1.004 in four days. The tank was capped and chilled to 38F on day six.

On day seven, I dumped yeast from the bottom of the tank and injected biofine,a cold-side fining agent, into the tank to drop remaining yeast and suspended protein. If you want to "lager" the beer to achieve a cleaner flavor profile, hold off on the yeast dump and cold-side finings for up to four weeks. I also force carbonated until the tank pressure reached 10PSI at 38F at this time.

On Day 10, The beer was clear and well-carbonated, so I kegged it! Yield was a little over five full slim kegs. The turnaround time for this beer was quite rapid, and as can be seen from my method, the traditional three to four week lagering period that is traditional for Kölsch was skipped almost entirely. This left a beer that was definitely less "clean" than a traditional Kölsch, with more fruity esters that came across as pear juice and a subtle banana note in the finished beer.

Conclusion:

Overall, This recipe worked as intended, albeit with a few tweaks I would add if redoing this recipe. The Brewers crystals lightened the body without drastically increasing the attenuation level of the beer as was expected. The starting and finishing gravities of 1.043 and 1.004 respectively are numbers that are more often seen in an American Lager rather than a Kölsch. Indeed, the low bitterness level produced by this recipe also put it in the American Lager camp. If I were to redo this recipe, I would increase the bitterness since the low IBUs allowed a sweet graininess to come through a bit more than I would like. Increasing the hops both at 60 and 30 minutes would help to balance out that grainy character.

A very good summer refresher, this recipe is a solid base for a light, clean, and quaffable beer. The relatively clean fermenting OYL-044 Kölsch II strain from Omega Yeast Labs worked its magic quickly and readily dropped out of the beer, enabling the production of a beer with a somewhat lager-like profile. The 10-day turnaround time from brew day to keg is also a feat very difficult to achieve if using a lager yeast. There was a pleasant, but distinctly ale-like subtle pear fruitiness early on in the beer that seemed to dissipate after a couple of weeks in the keg. I will likely revisit this recipe in the future, since it seems I always drift back to brewing a Kölsch-style beer when the weather starts to get hot.