Perpetuum Sour

(5 gallons/19 L, all-grain)
OG = 1.058 FG = 1.002 IBU = 11 SRM = 4 ABV = 7.4%

Ingredients

5.25 lbs. (2.4 kg) German Pilsner malt
4.4 lbs. (2 kg) American pale malt
15 oz. (0.43 kg) rolled oats
13 oz. (0.37 kg) flaked wheat
10 oz. (0.28 kg) wheat malt
2.75 AAU Willamette whole hops (60 min.) (0.5 oz./14 g at 5.5% alpha acids) East Coast Yeast ECY01 (BugFarm) or Wyeast 3278 (Belgian Lambic Blend) cultures

Step by Step

Mash at 156 °F (69 °C) for 60 minutes then raise the temperature to 168 °F (76 °C) for 15 min. Boil 75 minutes adding hops per schedule. Chill to 65 °F (18 °C), aerate the wort with filtered air or pure O2 and pitch yeast.

Primary ferment in a red wine barrel at 68 °F (20 °C) or another fermenter with 1 oz. (28 g) of red wine-soaked oak cubes. Allow to age in the barrel or on the oak at around 70 °F (21 °C) until you are happy with the flavor, and the gravity readings remain stable from one month to the next. Bottle or keg a portion, carbonating to 2.5 volumes of CO2. Refill the barrel wort or beer, repeating the process.

Perpetuum Sour

(5 gallons/19 L, partial mash)
OG = 1.058 FG = 1.002 IBU = 11 SRM = 4 ABV = 7.4%

Ingredients

3.3 lbs. (1.5 kg) light liquid malt extract
1.5 lbs. (0.68 kg) dried Pilsen malt extract
2 lbs. (0.91 kg) German Pilsner malt
15 oz. (0.43 kg) rolled oats
13 oz. (0.37 kg) flaked wheat
10 oz. (0.28 kg) wheat malt
2.75 AAU Willamette whole hops (60 min.) (0.5 oz./14 g at 5.5% alpha acids) East Coast Yeast ECY01 (BugFarm) or Wyeast 3278 (Belgian Lambic Blend) cultures

Step by Step

Place crushed grains in a large muslin bag. Heat 2 gallons (7.6 L) water to 169 °F (76 °C) and place the grain bag into the water. Mash at 156 °F (69 °C) for 60 min., then raise the temperature to 168 °F (76 °C) for 15 min. Place the grain bag in a colander and rinse with 1.5 gallons (6 L) hot water, about 170 °F (77°C) collecting the runoff. Top off to 6.25 gallons (24 L) adding the dried and liquid extract while the pot is off heat to avoid scorching. Boil 75 minutes adding hops per schedule. Follow the remainder of the all-grain recipe.