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Kolsch & Belgian Dubbel at end of primary fermentation
Kolsch & Belgian Dubbel at end of primary fermentation

Brewing a Brett Beer

Previously in this series of articles on How to brew different Styles of Beer? we covered Brewing an English IPA, this time the Beer Style comes from the ‘American Wild Ale’ category in the BJCP 2014 Guidelines and is the style of a Brett Beer.

20 gal electric brewing system
20 gal electric brewing system

In the following sections we are going to examine different aspects of this style such as its background, the style guidelines, ingredients used, base recipes, souring process, and finally the outcome of brewing batches of these beers.


According to the BJCP Guidelines the history of this style is as follows:

Modern American craft beer interpretations of Belgian wild ales, or experimentations inspired by Belgian wild ales or historical English beers with Brett. 100% Brett beers gained popularity after the year 2000; Port Brewing Mo Betta Bretta was one of the first popular examples.

Milling grains
Milling grains

Commercial examples of this style include Russian River Sanctification, Crooked Stave Hop Savant, Prairie Hop, Jester King El Cedro, Anchorage
Bitter Monk, Allagash Interlude, Goose Island Sofie, Bruery Saison Rue, Boulevard Saison Brett, Victory Helios, St. Somewhere Saison Athene, Logsdon Seizoen Bretta, and Hill Farmstead Art.


In the BJCP 2008 Style Guidelines a specific category did not exist for sour beers. In the revised 2014 Guidelines an American Wild Ale category was introduced as follows:

BJCP 2014
Category 28: American Wild Ale
Styles 28A: Brett Beer
28B: Mixed-Fermentation Sour Beer
28C: Soured Fruit Beer

The guidelines specify that the vital statistics vary by style.

Below are those for the Belgian Dubbel style:

  • Original Gravity (OG) = 1.062 – 1.075
  • Final Gravity (FG) = 1.008 – 1.018
  • Alcohol By Volume (ABV) = 6.0 – 7.6%
  • Bitterness (IBUs) = 15 – 25
  • Color (SRM) = 10 – 17

and the statistics for the Kolsch style are:

  • 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 – 5.0

Both of these formed the base beers for the Brett inoculations.


Bring wort to the boil
Bring wort to the boil

According to the BJCP 2014 Guidelines the following are characteristic ingredients used in the brewing of a Belgian Dubbel:

  • Malts: Impression of complex grain bill, although traditional versions are typically Belgian Pils malt with caramelized sugar syrup or other unrefined sugars providing much of the character.
  • Hops: Saazer-type, English-type or Styrian Goldings hops commonly used.
  • Yeast: Belgian yeast strains prone to production of higher alcohols, esters, and phenolics are commonly used.
  • Water: Not specified.
  • Additions: No spices are traditionally used, although restrained use is allowable (background strength only).
Rolling boil in Brew Kettle
Rolling boil in Brew Kettle

and for a Kolsch the characteristic ingredients are:

  • Malts: German Pils 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 specified.


Below are the recipes for 15 gallon and 20 gallon batches of the Belgian Dubbel and Kolsch respectively together with some analysis on how they comply with the style guidelines:

– Belgian Dubbel –

Belgian Dubbel primary fermentation
Belgian Dubbel primary fermentation


  • 20 Lb Pilsner malt
  • 10 Lb Maris Otter*
  • 1.4 Lb Biscuit malt
  • 1.4 Lb Aromatic malt
  • 1.4 Lb CaraMunich malt
  • 1.4 Lb Special B malt
  • 2.8 Lb sugar
  • 12.8 oz Chocolate malt**
  • 3.7 oz Tettnang hops (bittering – 90 mins)
  • 0.7 oz Styrian Goldings hops (flavoring – 15 mins)
  • 0.7 oz Hallertau hops (falvoring – 15 mins)
  • Wyeast 1214 Belgian Abbey yeast

* original recipe was based on a Chimay Red clone which used 100% Maris Otter but usually Pilsner malt would be used in a Belgian Dubbel. We only had 20 Lb of Pilsner malt available so made up the remainder with Maris Otter.

** we did not have any Dark Candi sugar, only Clear, so we steeped the Chocolate malt in some hot water and added this to the mash before batch sparging in order to add color without flavor or extra sugars to the wort.


  • Mash @ 152 deg F using BIAB (Brew In A Bag) then sparge to obtain the required volume and pre-boil gravity.
  • 90 minute boil.


  • Pre-boil Gravity: 1.058
  • OG: 1.065
  • FG: 1.008 (pre-Brett)
  • ABV: 7.48%


  • Malts: The grain bill was more complex than would usually be associated with this style but most of it was derived from the Chimay Red clone recipe.
  • Hops: The hops choices are within style as they are noble varieties.
  • Yeast: The Belgian Abbey yeast strain is within style.
  • Statistics: This batch was at the top of the style for alcohol content with the Starting and Finishing Gravities both at the bottom of the respective ranges to give a dry beer.

– Kolsch –

Kolsch primary fermentation
Kolsch primary fermentation


  • 36 Lb Pilsner malt
  • 2 Lb Munich malt
  • 2 Lb Wheat malt
  • 1.75 oz Tettnang hops (bittering – 60 mins)
  • 2.9 oz Saaz hops (flavoring – 20 mins)
  • 2.0 oz Tettnang hops (flavoring – 20 mins)
  • 1.2 oz Saaz hops (aroma – 0 mins)
  • 1.2 oz Tettnang hops (aroma – 0 mins)
  • WLP029 German Ale/Kölsch yeast


  • Mash @ 150 deg F using BIAB then sparge to obtain the required volume and pre-boil gravity.
  • 60 minute boil.


  • 1st runnings: 1.079
  • 2nd runnings: 1.036
  • OG: 1.048
  • FG: 1.012 (pre-Brett)
  • ABV: 4.73%


  • Malts: A Pilsner base malt with some Wheat for head retention and Munich to add maltiness kept this grain bill largely within style.
  • Hops: Tettnang is a German hop variety though the choice of Saaz is slightly unusual but still a noble variety.
  • Yeast: This is a typical German Ale yeast used for this style of beer.
  • Statistics: The Starting Gravity was within style though the Finishing Gravity of the initial fermentation was 1 point too high whilst the alcohol content remained within the guidelines.


Kolsch & Belgian Dubbel at end of primary fermentation
Kolsch & Belgian Dubbel at end of primary fermentation

I am a member of the State College Homebrew Club and back in February we had a brew day where we produced two beers to be split between members and fermented with different yeast strains.

I took a carboy fill of the Belgian Dubbel and Kolsch then fermented each with the yeast mentioned previously in the ingredients lists. Once fermentation was complete I then split each 5 gallon batch in half and added Brett to half of each as follows:

  • Belgian Dubbel – Brett Dex. This was isolated by a fellow homebrewer from a bottle of Jolly Pumpkin out of Dexter, Michigan. It is similar to WLP650 Brettanomyces bruxellensis which is described as:

Medium intensity Brett character. Classic strain used in secondary fermentation for Belgian style beers and lambics. One Trappist brewery uses this strain in secondary fermentation and bottling to produce their characteristic flavor.

  • Kolsch – Brett Trois. White Labs name this strain as WLP644 Saccharomyces “bruxellensis” Trois and describe it as follows:

This Belgian strain, used traditionally for 100% Brettanomyces fermentations, produces a slightly tart beer with delicate characteristics of mango and pineapple.

Belgian Dubbel bubbling from Brett Dex
Belgian Dubbel bubbling from Brett Dex

Both beers were started at 75 degrees F for 2-3 weeks and after time large bubbles started to form. Due to limited space in my temperature controlled freezer they had to be moved in order to make way for other beers being brewed so were brought upstairs into the lounge and placed in an insulated fermentation bag near the fireplace to keep them around 68 degrees F for the remainder of the 8 weeks.

Towards the end of this period an oily film was visible on the top of the Belgian Dubbel which apparently can happen but no pellicle formed on either.


According to the style guidelines a Brett Beer should have the following characteristics:

  • Appearance: Variable by base style, but often pale. Clarity can be variable; some haze is not a fault.
  • Aroma: Variable by base style. Young Brett-fermented beers will possess more fruity notes (e.g., tropical fruit, stone fruit, or citrus), but this is variable by the strain(s) of Brett used. If the beer is fermented with a brewer’s yeast in addition to Brett, some of the character of the primary yeast should remain. Beers fermented with a more phenolic brewer’s yeast (such as certain Belgian strains) will tend to result in a funkier (wet hay, farmyard, horse blanket) profile after Brett is finished than those with a cleaner primary strain. A faint sourness is acceptable but not required, and should not be a prominent character.
  • Flavor: Variable by base style. Beers fermented with both brewer’s yeast and Brett are often as funky as Orval, especially if based on a Belgian style like saison. Light sourness is acceptable (prominent acidity is a fault), but not required; the beer may be lightly tart, but should not be truly sour. Fruitier when young, gaining more funk as it ages, but depends on the strain. May have light acetic acid but not at an objectionable level. Should not have lactic acid (Brett is incapable of producing it). Malt flavors are often less prominent than in the base style. Often dry, crisp finish due to high attenuation.
  • Mouth-feel: Variable by base style. Generally a light body, lighter than what might be expected from the base style. Judge’s discretion if the thinness of the body detracts from the overall impression. Generally moderate to high carbonation, which can often seem bright and crisp on the tongue. Head retention is variable, but is often poor in longer-aged examples.
  • Overall: An interesting and refreshing variation on the base style, often drier and fruitier than expected, with at most a light acidity.

How did my batches of Brett Beers turn out?

Belgian Dubbel with Brett Dex
Belgian Dubbel with Brett Dex

This was my first attempt at sour beers and through good fortune rather than good planning I pitched the right Brett strain into the most appropriate beer as the Brett Dex would have totally dominated the Kolsch and the Brett Trois would have been undetectable in the Belgian Dubbel.

Here are the actual vital statistics for the Belgian Dubbel:

  • OG: 1.065
  • FG: 1.004 (1.008 pre-Brett)
  • ABV: 8.0%

and for the Kolsch:

  • OG: 1.048
  • FG: 1.006 (1.012 pre-Brett)
  • ABV: 5.5%
Kolsch with Brett Trois
Kolsch with Brett Trois

With both beers the additional attenuation from the Brett strains took the Final Gravities (FG) lower than the style guidelines as you would expect (to avoid bottle bombs) and hence pushed the alcohol content for both above the range for the styles.

The tasting notes are as follows:

Belgian Dubbel – Hazy dark amber in color with a cream head. A sour and Belgian yeast aroma. Belgian Dubbel flavor with dominant Brett. Moderate carbonation with a medium body and sour after-taste.
Rating: 3.5/5.0

Kolsch – Golden and slightly hazy in color with a thin white head. A fruity aroma. Flavor is toffee and malty with a little touch of sourness. Moderate carbonation with a medium body and slight sour after-taste.
Rating: 3.0/5.0

My initial aim with the Belgian Dubbel was to get something similar to how Orval has that extra Brett dimension, the result achieved was closer to a 100% Brett beer in flavor. The Kolsch has very little Brett character so it will be interesting to see how these beers develop and change over time.

What’s Next?

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

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