Imperial Stout with Dried Mushrooms and Cumaru

Imperial Stout with Dried Mushrooms and Cumaru

(5 gallons/19 L, all-grain)
OG = 1.097   FG = 1.017
IBU = 61  SRM = 80   ABV = 10.6%

Courtesy of Daniel Ropelato, this imperial stout incorporates dried mushrooms and the unique flavors of cumaru seeds (tonka beans).

Ingredients
10 lbs. (4.5 kg) pale ale malt
3 lbs. (1.4 kg) flaked oats
1.5 lbs. (680 g) Caramunich® III malt
2.5 lbs. (1.1 kg) Carafa® III malt
3 lbs. (1.4 kg) Belgian dark candi syrup, D-90
3.7 AAU Challenger hops (first wort hop) (0.5 oz./14 g at 7.5% alpha acids)
7.5 AAU Challenger hops (60 min.) (1 oz./28 g at 7.5% alpha acids)
7.5 AAU Challenger hops (30 min.) (1 oz./28 g at 7.5% alpha acids)
7.5 AAU Challenger hops (10 min.) (1 oz./28 g at 7.5% alpha acids)
1 oz. (28 g) dried porcini mushrooms
8 cumaru beans (or use vanilla extract, to taste)
SafAle S-04, or Wyeast 1028 (London Ale), or LalBrew Nottingham yeast
3⁄4 cup corn sugar (if priming)

Step by step
This recipe uses reverse osmosis (RO) water. Adjust all brewing water to a pH of 5.5 using phosphoric acid. Add 1 tsp. calcium chloride to the mash.

This recipe uses a step mash. In 26 quarts (25 L) water, mash the pale ale malt and flaked oats at 126 °F (52 °C) for 10 minutes. Raise to 156 °F (69 °C) and hold for 120 minutes. Start recirculating wort. Add the Carafa® and Caramunich® malts and raise the temperature to 168 °F (76 °C) for 15 minutes. Sparge slowly and collect 6.5 gallons (24.5 L) of wort. 

Boil the wort for 90 minutes, adding hops at the times indicated. First wort hops go in the kettle prior to sparging. Add the candi syrup at the end of the boil and stir well until dissolved.

Chill the wort to 68 °F (20 °C), pitch the yeast, and ferment until complete. 

Make a mushroom extract by soaking mushrooms in 100 mL (a little less than half a cup) of vodka while the beer is fermenting. Strain the extract off the mushrooms prior to adding. Make cumaru extract by soaking 8 whole beans in 300 mL of vodka for at least two months. Strain and use to taste; start with about 10 mL. Add the mushroom and cumaru extracts at packaging to taste. Rack the beer, prime, and bottle condition, or keg and force carbonate.

Imperial Stout with Dried Mushrooms and Cumaru

(5 gallons/19 L, extract with grains)
OG = 1.097   FG = 1.017
IBU = 55   SRM = 80   ABV = 10.6%

Ingredients
8.5 lbs. (3.9 kg) pale liquid malt extract
1.5 lbs. (680 g) Caramunich® III malt
2.5 lbs. (1.1 kg) Carafa® III malt
3 lbs. (1.4 kg) Belgian dark candi syrup, D-90
3.7 AAU Challenger hops (first wort hop) (0.5 oz./14 g at 7.5% alpha acids)
7.5 AAU Challenger hops (60 min.) (1 oz./28 g at 7.5% alpha acids)
7.5 AAU Challenger hops (30 min.) (1 oz./28 g at 7.5% alpha acids)
7.5 AAU Challenger hops (10 min.) (1 oz./28 g at 7.5% alpha acids)
1 oz. (28 g) dried porcini mushrooms
8 cumaru beans (or use vanilla extract, to taste)
SafAle S-04, or Wyeast 1028 (London Ale), or LalBrew Nottingham yeast
3⁄4 cup corn sugar (if priming)

Step by step
Use 6.5 gallons (24.5 L) of water in the brew kettle; heat to 158 °F (70 °C). 

Steep the malts for 30 minutes. Remove and rinse. Turn off the heat. Add the malt extract and stir thoroughly to dissolve completely. Turn the heat back on and bring to a boil. 

Follow the remainder of the all-grain recipe instructions.

Tips for Success:
The brewer called the mushrooms funghi secchi, but that just means dried mushrooms. He said they were Italian; further questioning led me to believe they were porcini mushrooms. I think any earthy, wild mushrooms would work, but porcinis are particularly intense. Specialty or gourmet cooking supply stores carry them.

Cumaru seeds are also called tonka beans in North America and other places (they are quite large, thumb-like in size). If you can’t get your hands on cumaru then use vanilla (cumaru is sometimes called Amazon vanilla, but it has an almond-like aroma). Vanilla extract can be made in the same way as the mushroom extract, or commercial extract (natural, please) can be used. Alternatively, the batch can be split and the base beer dosed with the vanilla and mushrooms directly, then the two batches can be blended to achieve the desired flavor profile.

Dark candi syrup was all that was specified in the recipe so I would use something like D-90 candi syrup. The brewer originally made the syrup at home, so a commercial substitute is recommended.