RPB’s Imperial Oatmeal Stout

RPB’s Imperial Oatmeal Stout

(5 gallon/19 L, all-grain)
OG = 1.088 FG = 1.032
IBU = 30 SRM = 70 ABV = 8%

Ingredients
14.2 lbs. (6.4 kg) 2-row malt
2.1 lbs. (0.52 kg) chocolate malt
1.5 lbs. (0.68 kg) flaked oats
1.15 lbs. (0.52 kg) Briess Blackprinz® malt
1.75 AAU Cluster hop pellets (first wort hop) (0.25 oz/7 g at 7% alpha acids)
3.5 AAU Cluster hop pellets (60 min.) (0.5 oz./14 g at 7% alpha acids)
3.5 AAU Cluster hop pellets (30 min.) (0.5 oz./14 g at 7% alpha acids)
5 oz. (142 g) lactose powder (0 min.)
Wyeast 2035 (American Lager) or White Labs WLP840 (American Lager) yeast
2⁄3 cup corn sugar (if priming)

Step by Step
Ramp mash bed up through conversion, looking to target 55% real degree of fermentation (RDF). When the grain bed reaches mash out temperature of 168 °F (76 °C), begin the lauter. During the sparge phase, add the first wort hops to the brewpot. This is a 60-minute boil adding the hops at the times indicated and the lactose at the end of the boil. Ferment at 55 °F (13 °C) with lager yeast. After primary fermentation is complete, rack the beer to a secondary and condition for one month. At RPB, the Imperial Oatmeal Stout was then split and aged on varying amounts of vanilla beans and cocoa beans in bourbon barrels for six months. Bottle or keg as normal.

RPB’s Imperial Oatmeal Stout

(5 gallon/19 L, partial mash)
OG = 1.088 FG = 1.032
IBU = 30 SRM = 70 ABV = 8%

Ingredients
8 lbs. (3.6 kg) golden liquid malt extract
2 lbs. (0.91 kg) 2-row pale malt
2.1 lbs. (0.52 kg) chocolate malt
1.5 lbs. (0.68 kg) flaked oats
1.15 lbs. (0.52 kg) Briess Blackprinz® malt
1.75 AAU Cluster hop pellets (first wort hop) (0.25 oz/7 g at 7% alpha acids)
3.5 AAU Cluster hop pellets (60 min.) (0.5 oz./14 g at 7% alpha acids)
3.5 AAU Cluster hop pellets (30 min.) (0.5 oz./14 g at 7% alpha acids)
5 oz. (142 g) lactose powder (0 min.)
Wyeast 2035 (American Lager) or White Labs WLP840 (American Lager) yeast
2⁄3 cup corn sugar (if priming)

Step by Step
Mix the 2-row pale malt and flaked oats in a large muslin bag and place it in a large brew pot with 4.5 qts. (4 L) water. Heat the grains mixture slowly until the temperature reaches 168 °F (76 °C) over the course of 45–60 minutes.

While the mash is heating, begin heating a separate pot with 3 gallons (11.4 L) water up to 168 °F (76 °C). Add an additional gallon (3.7 L) of water plus the crushed chocolate malt and Blackprinz® malt in a separate muslin bag once the mash has reached 168 °F (76 °C). After roasted grains have steeped for 10 minutes at this temper-ature, remove both grain bags and place in a colander. Slowly pour the remaining 2 gallons (7.8 L) over the grains to wash out the sugars. Bring to a boil, adding the liquid malt extract and first wort hops off heat just prior to reaching a full boil. Stir until extract is fully dissolved. This is a 60 minute boil, adding the hops at the times indicated and the lactose at the end of the boil. Chill the wort and top off the fermenter to 5 gallons (19 L) then aerate the wort heavily and pitch the yeast. Ferment at 55 °F (13 °C) with lager yeast. After primary fermentation is complete, rack to a secondary and condition for one month. At RPB, the Imperial Oatmeal Stout was then split and aged on varying amounts of vanilla beans and cocoa beans in bourbon barrels for six months. Bottle or keg as normal.