FLANDERS BROWN ALE/OUD BRUIN
A malty, fruity brown ale with touches of sourness and age. This is an advanced style that can be brewed by extract-with-grain or all-grain methods. Ferments at 65° F (18° C) and later at ambient temperatures. It takes about 1 year to be ready.
OG
FG
IBU
Color
Alcohol
1.040-1.074
(10-17.9 °P)
1.008-1.012
(2.0-3.1 °P)
20-25
15-22 SRM
30-43 EBC
4.0-8.0% ABV
3.2-6.3% ABW
Keys to Brewing Flanders Brown Ale/Oud Bruin:
Oud bruin is a bigger beer that has more malt character, more malt sweetness, and isn’t nearly as sour as a Flanders red ale. Think English old ale with a definite sour character. Long aging periods can also introduce a touch of sherry character consistent with an aged beer. The trick with oud bruin is to get the right amount of souring, just enough to provide a counternote to the residual malt sweetness but less sour than Flanders red.
Although you can use a sour mash technique or a pure Lactobacillus culture to create the sourness in this beer, my preference is to use the same blend that I use for Flanders red ale.
It takes some management of the bacterial cultures to create a subtle, controlled sourness. Bacteria have a tendency to keep consuming sugars unless something in their environment stops them. Unless you are willing and able to pasteurize your beer, having the right amount of alcohol in an oud bruin is probably the easiest way to keep the sourness in check. The right amount of alcohol, sourness, and residual malt sweetness are the keys to an excellent oud bruin.
I prefer to initially ferment the beer using neutral ale yeast. Once it has mostly fermented, I add the souring culture. The timing of the addition can make a difference in the final beer. If you add the culture early and the conditions are right, it can end up a bit too sour for the style, more like Flanders red ale. If you add the culture late and the conditions aren’t right for the organisms, the sourness will take a very long time to develop, or the sourness may never quite reach the level desired. Knowing the right moment to add the culture is something you will develop over several batches, with personal preference playing a big part in the timing. For me, the right time is when the beer is still fermenting but has slowed down considerably. I rack it to a second vessel, being careful to minimize oxygen pick-up, and then I add the souring culture. It is important to keep oxygen to a minimum, especially once there is alcohol in the beer. The more oxygen that gets in, the more acetic acid character it is likely to have. It will take some time for the sourness to become apparent. I like to keep it in a carboy with minimal headspace for about 1 month. At that point I rack to a keg, flush it with carbon dioxide, and store it around 65 to 70° F (18 to 21° C). I check the keg every few weeks, and when it is approaching the level of sourness I want, I move it to cold storage and force carbonate it.
RECIPE: FLANDERS BROWN ALE
OG: 1.070 (17.1 °P)
FG: 1.012 (3.1 °P)
ADF: 82%
IBU: 21
Color: 19 SRM (36 EBC)
Alcohol: 7.7% ABV (6.0% ABW)
Boil: 60 minutes
Pre-Boil Volume: 7 gallons (26.5L)
Pre-Boil Gravity: 1.060 (14.7 °P)
Extract
Weight
Percent
Pilsener LME (2.3 °L)
7.3 lbs. (3.31kg)
57.6
Munich LME (9 °L)
3.0 lbs. (1.36kg)
23.7
Wheat LME (4 °L)
0.5 lb. (227g)
3.9
Steeping Grains
CaraMunich (60 °L)
0.75 lb. (340g)
5.9
Aromatic (20 °L)
0.5 lb. (227g)
3.9
Special “B” (120 °L)
0.5 lb. (227g)
3.9
Black Malt (600 °L)
2.0 oz. (57g)
1.0
Hops
IBU
Kent Goldings 5% AA, 60 min.
1.1 oz. (31g)
20.5
Yeast
White Labs WLP001 California Ale, Wyeast 1056 American Ale, or Fermentis Safale US-05
Wyeast 3763 Roeselare Blend or White Labs WLP655 Belgian Sour Mix I
Fermentation and Conditioning
Use 13 grams of properly rehydrated dry yeast, 3 liquid yeast packages, or make an appropriate starter. Ferment at 65° F (18° C). When fermentation begins to slow, rack beer to a second container and add the souring culture. The culture will break down and consume the remaining sugars that the yeast did not consume or was unable to consume, adding sourness and character to the beer. Store the beer around 65 to 70° F (18 to 21° C) until the sourness becomes noticeable, then move to cold storage to suppress further development. When finished, carbonate to approximately 2 to 2.5 volumes.
All-Grain Option
Replace the Pilsener extract with 9.75 lbs. (4.42kg) continental Pilsener malt. Replace the wheat extract with 0.5 lb. (227g) wheat malt. Replace the Munich extract with 4 lbs. (1.81kg) Munich malt. Mash at 152° F (67° C). Increase the pre-boil volume as needed to allow a 90-minute boil, which will help reduce DMS in the beer.
