Brewing a Kölsch V2

Previously in this series of articles on How to brew different Styles of Beer? we covered Brewing a Clone Beer (Westvleteren 12), this time the Beer Style comes from the ‘Pale Bitter European Beer’ category in the BJCP 2015 Guidelines and is the style of a Kölsch, which is in fact a re-brew of the recipe that reached the final round of the National Homebrew Competition (NHC) 2015.

For details on the background and style guidelines of this style please refer to the previous article on Brewing a Kölsch.

Brewing Improvements

As a reminder the BJCP 2015 Guidelines have the vital statistics of a Kölsch as follows:

• Original Gravity (OG) = 1.044 – 1.050
• Final Gravity (FG) = 1.007 – 1.011
• Alcohol By Volume (ABV) = 4.4 – 5.2%
• Bitterness (IBUs) = 18 – 30
• Color (SRM) = 3.5 – 5

In my Homebrew Competition Feedback article I examined the feedback received on version 1 of this beer in both the first and final rounds of NHC 2015 to try identify what improvements could be made to take it from a 37-40.5 scored beer and take it firmly into the 40’s.

My verdict reached after examining the feedback was as follows:

This beer appears to be close to spot on but could probably be improved by a slightly lower mash temperature which would allow it to attenuate a bit more and restrain the maltiness whilst at the same time upping the alcohol content slightly towards the upper half of the ABV range. Lagering might also help with rounding out and smoothing out the flavor whilst giving the hops time to lose their intensity.

This therefore required both recipe and process adjustment:

• Recipe:
  • Increasing the Pilsner malt by 0.5Lb and reducing the Munich malt by the same amount to hopefully reduce the perceived maltiness.
• Process:
  • Lowering Saccharification step of the mash from 150F to 148F to make a more attenuable wort i.e. shorter chained sugars for yeast to consume.
  • Extending the lagering from one week, due to rushed brewing, to almost 4 weeks to help the hops drop out more.

Everything else was to remain unchanged … in theory!

Ingredients & Recipe

According to the BJCP 2015 Guidelines the following are characteristic ingredients used in the brewing of a Kölsch:

• Malts: German Pilsner or Pale malt. Up to 20% wheat malt may be used, but this is quite rare in authentic versions.
• Hops: Traditional German hops (Hallertau, Tettnang, Spalt or Hersbrucker).
• Yeast: Attenuative, clean ale yeast.
• Water: Water can vary from extremely soft to moderately hard.
• Additions: None.

The tweaked recipe used was as follows:

• 8.5 Lb German Pilsner malt
• 1.0 Lb Munich malt
• 0.5 Lb White Wheat malt
• 0.75 oz Hallertauer hops (bittering – 60 mins)
• 1.0 oz Saaz hops (flavoring – 20 mins)*
• 1.0 oz Hallertauer hops (flavoring – 20 mins)
• 0.5 oz Saaz hops (aroma – 0 mins)**
• 0.5 oz Hallertauer hops (aroma – 0 mins)**
• White Labs WLP029 German Ale/Kölsch yeast

* 0.5 oz substituted with Spalt hops due to a late delivery of Saaz.
** 0.5 oz of Saaz hops substituted with Hallertauer due to a late delivery of Saaz.

Both hop substitutions kept the recipe within style.

Process

The 5 gallon batch of beer was brewed following these steps with only the middle step mash temperature adjusted:

• Charcoal filtering the borough water and leaving it to stand overnight in order to vent off the chlorine.
• Measuring out and milling the grains, also measuring out the hops and Irish Moss.
• Sterilizing the fermentation equipment.
• Heating the strike water to 124 deg F before mashing-in (adding the grist to the hot water).
• Mashing for 20 mins at 122 deg F for Protein rest to help with final beer clarity.
• Raise temperature to 148 deg F for Saccharification rest so the starches convert into sugars (pH 6.2).
• Raising the temperature to 168 deg F to mash-out and stop enzymatic activity i.e. halt the conversion of starches to sugars.
• Removing the grain bag.
• Boiling for 10 mins to allow time for the hot break to clear.
• Continue boiling for 40 mins with the bittering hop addition.
• Continue boiling for 5 mins with the flavoring hop additions.
• Adding Irish Moss at 15 mins to help clear the beer.
• Add aroma hops additions at 0 mins (flame-out).
• A yeast starter was prepared comprising of 8 oz of DME (Dry Malt Extract) in two liters of water and placed in a flask on a stir plate together with one packet of yeast.
• Yeast nutrient was added to the wort once it had been cooled.
• Wort was aerated with Oxygen (60 secs) via a diffusing stone connected to an O2 tank with a regulator.
• Yeast starter was decanted prior to pitching into the wort so that most of the spent wort did not go into the beer.
• Primary fermentation was at 67 deg F for two weeks in a temperature controlled freezer.
• The beer was racked off the trub (sediment) into the secondary fermenter and held at 54 deg F for almost four weeks before cold crashing.
• Beer was force carbonated to 2.5 volumes of CO2 after cooling the beer to 36 deg F.

Outcome

How did my batch of Kölsch turn out?

As it turns out there were a number of problems encountered and that this batch was not simply a re-brew of the previous recipe!

Here are the actual vital statistics:

• OG: 1.040 (1.047)
• FG: 1.012
• ABV: 4.59%
• Bitterness: 28.9 IBUs*
• Color: 4.1 SRM*

* calculated via BeerSmith software.

The Starting Gravity was disappointingly too low which appears to have been due to the pH being too high (6.2 this time compared to 5.6 last time) – this may have impacted the enzymatic activity within the mash and hence the resulting conversion of starches to sugars.

I attempted to improve the mash pH by adding 1 tsp of gypsum but this made no difference.

There was also a problem with the mash volume – it turns out that previously this was calculated too low due to a BeerSmith error that did not show 2.16 quarts (approx 2 litres) of water for the Protein rest step. This time it was included so the mash had more volume.

I used the gravity adjustment tool within BeerSmith to bring the Starting Gravity up to 1.047. What this did was to work out how much Dried Malt Extract (DME) to boil and then cool prior to adding to the wort. 1.0 Lb of Extra Light DME was boiled in 2 quarts of water for 10 mins. By using the Extra Light version my thinking was that this should minimize any changes in the maltiness of the wort.

I had expected a better attenuation due to the tweak to the grain profile in the recipe and prolonged lagering but it turns out that this did not occur. Perhaps a further lowering of the mash temperature might help achieve this?

The tasting notes are as follows:

Straw in color with a white head and a slight chill haze. A yeasty aroma and malty flavor. Average carbonation with a medium-light body.

This should have been a straight forward re-brew but turned out to be anything but that with the hop ingredients shortage, mash pH and volume issues resulting in a lower Starting Gravity plus not getting the increased attenuation that was predicted.

The slight chill haze may have been down to some suspended yeast that will drop out in the bottle or could be as a result of not using gelatin this time round. The lower gravity was not detectable when tasting the beer and is still within the style guidelines.

The resulting beer once carbonated did taste good though so it will be interesting to see if these issues hinder the scoring at NHC 2016 or not.

What’s Next?

In my next article in this series I will be examining Brewing a Belgian Golden Strong Ale which is in the ‘Strong Belgian Ale’ category so please check back for that article to be published.

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