Thursday, March 3, 2016

Screwy's Kölsch Style Beer Brewday

While browsing through the online beer forums recently one post in particular grabbed my attention. It was from a fellow brewer, who after much debate over which style of beer to brew next, had decided to brew a batch of Kölsch beer. Always on the lookout for new and interesting styles of beer to brew, it seemed like this would be a perfect opportunity for me to join in the fun and brew one up too. Having the opportunity to brew the Kölsch style also presented me with a challenge, since up until now this style of beer still remained a mystery to me. You see from a brewing perspective a fair amount of reliable information had already been published explaining how to brew a classic Kölsch beer. But having never actually tasted a Kölsch beer before myself, some taste comparisons of authentic Kölsch beers would be needed, in order for me to judge how close mine was to the style.

Screwy's Kölsch Style Beer
The Kölschbier Style

Officially, the only way to brew an authentic Kölschbier, is to brew it in a brewery that is located within the Cologne (Köln) region of Germany. Even though the brewers in Köln have been brewing mostly Ales for well over a thousand years, the Kölsch style we drink today has only been in existence for about a hundred years. Thanks to the cooperation of Kölsch brewers in 1948, the Kölsch Konvention was created in order to formalize a modern brewing standard for the style. You see in order for the beer to be true to the Kölsch style it had to be fermented with top fermenting yeast, pale in color, very clear and hop accentuated. More recently in 1986, the Kölsch Konvention was amended to include a regional appellation, whereby only breweries that were located within a 50 kilometer zone around Cologne, Germany could legally be called Kölsch beer.

Screwy's Kölsch Style Recipe

This Kölsch style recipe is my interpretation of how a great tasting Kölsch beer can be brewed. The recipe is based in part on the beer style information published by the BJCP that is available for free on their website. The entire beer brewing process is part art and part science and ultimately the best way for a brewer to hone their brewing skills will be in brew room. Brew day is when everything comes together. It is where sanitization, yeast handling, pitching rate and fermentation control combine with grain, hops and water to influence the taste of the finished beer.

Every single step in the overall brewing process has some affect on the quality of your finished beer. Documenting what went right, and possibly what went wrong, on each brew day will be help ensure that your future brew days will go more smoothly. Taking the time to write down brewing notes is especially important whenever a recipe or a new brewing process has been modified. This way any improvements that were made, can later be referred to while brewing future batches. It is important when evaluating your beer for flavor, color, aroma and other characteristics of the style, that you also ask others for their opinion too. This way a comparison of their impressions of the beer are also compared against your own biased impressions. The honest feedback that you receive from beer drinkers, who are familiar with the style, will be helpful when evaluating your beer against authentic versions of the style.

The Water Profile

The water of Cologne, Germany is made up of two thirds ground water and one third river bank filtrate from the Rhine river. This mixture of groundwater water flows slowly through the subsoil of the Cologne Basin where the water is naturally filtered as it is collected into an enormous underground reservoir. The effect of extensive natural filtration results in water that is softer and lower in nitrate levels than the original groundwater and it is also free of pathogens and hazardous substances.

When brewing a Kölsch beer it is recommended to use soft water that has low levels of bicarbonates, calcium and magnesium. These are the preferred water properties to produce the authentic soft mouth feel of the style. A similar water profile that comes very close to that recommended for brewing a Kölsch is the Pilsner water profile. 

Replicating The Kölsch Region Water Profile
 My Personal Suggestions

"Prepare your brewing water at least a day or two before you plan to brew with it. This will save you a lot of time and leave you with one less thing to be done on brew day."

Waiting for brewing water to stabilize, in between water adjustments and taking pH readings, can prolong a brew day by several hours. If possible fill a container with RO water the day before and then slowly stir in the brewing salts and minerals needed to build the water profile. When adding in acid or base adjustments make them in small increments, then wait 20 minutes for the water to stabilize before taking a pH reading. Making smaller pH adjustments and then allowing sufficient time in between readings will reduce the chances of overshooting or undershooting your target pH value.

Calibrate your pH meter

"Buffers, moles, ions, cations, anions, acid, base, atomic weights, valence, electrons, Lewis structures, central atoms, bonding sites, mg/L as CaCO3, mg/L, ppm, milliliters, teaspoons. Really? Let me just arrange all that information in a way that's interesting and understandable by the majority of brewers" ~ Screwy Brewer

Routinely calibratng and maintaining your digital pH meter is the only reliably way of getting accurate pH readings consistently. Doing so once a month, for less than time then it takes to drink a beer, you will be able to keep your pH meter in perfect working condition.

  • Never let the probe dry out, always make sure that the pH bulb is always submerged in storage solution when not in use
  • Each month be sure to calibrate your pH meter using the recommended calibration solution for your meter
  • Always be sure to sample liquids at a temperature no warmer than of 80F to greatly extend the life of the meter's pH bulb
Screwy's Kölsch Water Profile (15.0 Gallons RO Water)

03.00 g - Gypsum (calcium sulfate)
09.00 g - Calcium Chloride
07.00 g - Epsom Salt (magnesium sulfate)
02.00 g - Baking Soda
08.00 ml Lactic Acid

pH = 5.42 @ 74F (calculated)
Chloride/Sulfate ratio 0.99
Residual Alkalinity -126
055 ppm - calcium
011 ppm - magnesium
010 ppm - sodium
076 ppm - chloride
078 ppm - sulfate

Double Crushed Grains Ready For Mashing

Bittering Unit To Gravity Ratio

When attempting to determine the perceived bitterness level of a beer recipe it is important to consider more than just the International Bittering Unit value. To get a complete picture of the hop bitterness to malt sweetness ratio, the calculated IBU value of a recipe should also be compared to the original gravity value of the recipe. The ratio of hop bitterness to malt sweetness, or the recipe's BU:GU ratio, is easily calculated using the IBU and OG values of the recipe. The Screwy's Kolsch recipe has a BU:GU ratio of 0.428 which is just a little less than the middle range of the BU:GU scale. For comparison a Wheat beer has a BU:GU ratio of .500, which is right at the middle of the scale, while a Standard American Lager has a value of .250 which is near the lower end of the scale.

The math involved in calculating the BU:GU ratio for any recipe is not difficult at all to do. For example, the bitterness value of the Screwy's Kolsch recipe is 24 IBUs and that value can be entered directly into the calculation as BU. The OG of the recipe is 1.056 and after dropping the 1. and multiplying the .056 remainder by 1000, the resulting number is 56, which is used in the calculation as GU.

Estimated Recipe Properties

    IBU  = 24
    OG   = 1.056
    SRM = 12
    FG    = 1.011
    ABV = 6.0%

Calculating the BU:GU ratio for this recipe is done by dividing 24 by 56 to get .428 as the answer. Basically the higher the BU:GU number the more perceived bitterness the finished beer will have when drinking it.

BU:GU Ratio : 24 / 56 = .428 (BU:GU Ratio Of Popular Beer Styles)

Whirlpool After A Vigorous 90 Minute Boil

The Grain Bill (10 Gallon Batch)

There are just two German grains used in the recipe, Pilsner malt and Vienna malt. The Vienna malt is considered to be optional because a Kolsch beer can be brewed using only Pilsner malt.

22.00 pounds Pilsen (German) (95%)
01.00 pounds Vienna (German) (5%)
23.00 pounds total grain bill

The Hop Bill

Bagging pellet hops before adding them to the kettle will limit the amount of hop debris that would otherwise collect at the bottom of the kettle. Having too much hop debris at the kettle bottom increases the likelihood that some of the debris will be sucked and clog a plate or counter-flow chiller. Clearing out a clogged chiller is not something you want to be doing while cooling down gallons of really hot wort. The hop schedule itself was pretty straightforward, consisting of a single 60 minute bittering addition added to the kettle. 

Hallertauer (Germany) pellets
5.00 ounces Total Hop bill

The Yeast

Ferment this batch at 60F pitching 2 White Labs WLP029 - German Ale/Kölsch Yeast™ 'pure pitch' packages into each 5 gallon fermentor. Early on brew day morning remove the pure pitch packages from the refrigerator and put them on a counter top where they can slowly warm up to room temperature. Once the fermentors are filled and the cooled wort then oxygenated for a minute, pitch the yeast right from the pure pitch packages.

White Labs WLP029 - German Ale/Kölsch Yeast™

4 White Labs WLP029 - German Ale/Kölsch Yeast™
Pitched directly from the packages

Putting It All Together

The first time mashing with an electric brew in a bag system you will have to figure out how much grain and brewing water will fit inside the kettle without causing it to overflow. With eBIAB systems heating the strike water, mashing the grains, sparging and boiling the wort are all done in a single vessel. Before being able to successfully brew using an eBIAB brewing system, after having brewed on a traditional three tier brewing system, you will need to learn a new set of calculations. Having a separate hot liquor tank, mash tun and brew kettle made calculating mash thickness and preboil volumes pretty straightforward, because the three vessels used provide much more volume to work with. The volume calculations when using only a single vessel system will take little more thought, since all three brewing processes have to share the same kettle.

With eBIAB brewing the strike water and grain used in the mash are added to the kettle at the beginning of the mash. The grain is placed inside of a fine mesh bag so that the sugars can be extracted into the wort while preventing any grain from getting into the kettle. At the end of the mash the mesh bag and grain are raised above the wort, rinsed with sparge water and then discarded. Once the wort is heated to a boil the remainder of any eBIAB brewing process is exactly the as any other type of brewing process.

Screwy's Kölsch 1.056 Original Gravity Sample

If attempting eBIAB brewing for the first time, remember it may take a few brew days before becoming familiar with the volume calculations involved. Brewing software like ezBIAB Calculator© will make all the kettle size, water, grain and hop volume calculations easy to do. Just enter the kettle size in gallons, amount of grain and hops used in the recipe, and the boil off rate and the brewing software will do the rest. Having the ability to do what-if type calculations is also very helpful in answering eBIAB brewing questions related to kettle size, mash thickness, water, grain and hop volumes.   


13.125 gallons: Pre-boil Volume
11.250 gallons: Post-boil Volume
10.000 gallons: Packaged Volume
Efficiency: 70%
Actual  Wort : IBU=24, OG=1.056, SRM=12, FG=1.011, ABV= 6.0%
BU:GU Ratio     :         24      /        56 = .428  Range: 0.25 (sweet) to 1.0 (bitter)

Mash at 149° F for 90 minutes
Mashout at at 168° F for 10 minutes
Sparge at 168° F until 13.125 gallons of wort has been collected in the kettle

Summing It All UP

It is a good idea to record the highlights of each brew day soon after you have finished brewing, while everything is still fresh in your mind. After transferring the fermented beer into kegs I was able to take a good look at the bottom of the fermentors where I noticed how tightly packed the WLP 029 yeast cake had become. The remaining beer that was sitting on top of the yeast cake remained clear even after it had been sloshing around over it yeast for a while. The krausen ring created during the fermentation was soft and easy to wipe clean using a damp sponge and some water.

Yeast And Krausen Ring Left In Fermentor After Kegging

Near the end of the boil the wort was pumped through a counter flow chiller to sanitize it and returned back to the kettle in order to create a whirl pool. The hops used during the boil for bittering, flavor and aroma were removed from the kettle before adding the final knock out hop additions. Once the pump was turned off, it took about fifteen minutes for the wort to settle down inside the kettle, allowing the cold break to fall the kettle bottom below the valve opening. Once the wort in the kettle cleared it was run through the counter-flow chiller to cool it down and then collected inside the fermentors.

1.011 Final Gravity Reading

The fermenting beer was held at 60F throughout most of the primary fermentation before the temperature was raised one degree each day for three consecutive days. Once the final gravity had been reached the beer was then cold crashed at 36F for three days before it was kegged and force carbonated. The Kölsch beer style tastes great when carbonated cold at 12-15 psi for 10 days, although it will reach peak flavor and clarity after cold conditioning for up to 6 weeks before serving it.

Kölsch Carbonated To 2.75 Volumes

The preferred serving temperature for Screwy's Kölsch beer really depends on your own personal preference and it can vary from one beer drinker to another. For a crisper pour I like to serve my beer at 36F and then finish the glass before the beer reaches 45F. As the beer warms above 45F the crispness will begin to fade allowing more of the malt flavor and aroma to become noticeable. Pour yourself a tall glass and then savor every sip as you enjoy the full range of crispness, flavor and aroma this beer has to offer. You will be glad you did!


  1. Love it -- thanks for including us in your adventure!

  2. I'm curious about your sparge technique. I just bought the eBIAB system from High Gravity and completed three brew days so far but cannot hit my specific gravity numbers. Your eBIAB calculator is great, thanks for sharing! Do you reserve some of your preboil volume to later use for sparging?

    1. Congratulations on becoming the owner of a High Gravity eBIAB system, you're gonna love it. When the combined grain and water volume is larger than my kettle will hold I have to heat up extra sparge water in a separate kettle.

      Once the grains have been lifted up out of the kettle there is plenty of room for the sparge to hit my pre-boil volume. Typical recipes that I brew use between 22 and 23 pounds of grain, which limits me to around 12 gallons of water during the mash. Hope this helps.