Raspberry Robust Porter
(5 gallons/19 L, all-grain)
OG = 1.064 (15.7 °P) / 1.066 (16.2 °P) with fruit
FG = 1.017 (4.4 °P)
IBU = 30 SRM = 37 ABV = 6.5%
10.4 lb. (4.7 kg) American two-row malt (2 °L)
1.5 lb. (0.68 kg) Durst Munich malt (8 °L)
14 oz. (397 g) crystal malt (40 °L)
11.0 oz. (312 g) chocolate malt (350 °L)
7.0 oz. (198 g) black patent malt (525 °L)
3.0 lb. (1.36 kg) Oregon Fruit Products raspberry puree
6.65 AAU Kent Goldings pellet hops (60 min.) (1.33 oz./38 g at 5% alpha acid)
White Labs WLP001 (California Ale), Wyeast 1056 (American Ale) or Fermentis Safale US-05 yeast
Step by Step
Mill the grains and dough-in targeting a mash of around 1.5 quarts of water to 1 pound of grain (a liquor-to-grist ratio of about 3:1 by weight) and a temperature of 154 °F (68 °C). Hold the mash at 154 °F (68 °C) until enzymatic conversion is complete. Infuse the mash with near boiling water while stirring or with a recirculating mash system raise the temperature to mash out at 168 °F (76 °C). Sparge slowly with 170 °F (77 °C) water, collecting wort until the pre-boil kettle volume is around 6.5 gallons (24.4 L) and the gravity is 1.050 (12.3 °P).
The total wort boil time is 90 minutes. Add the bittering hops with 60 minutes remaining in the boil. Add Irish moss or other kettle finings with 15 minutes left in the boil. Chill the wort rapidly to 67 °F (19 °C), let the break material settle, rack to the fermenter, pitch the yeast and aerate thoroughly.
Use 12 grams of properly rehydrated dry yeast, 2.5 liquid yeast packages, or make an appropriate starter. Ferment at 67 °F (19 °C). When initial fermentation begins to slow, add raspberry puree to a second fermenter and carefully rack the beer onto the fruit. Fermentation should pick up again as the yeast consumes the fructose in the fruit puree. Once fermentation finishes, carbonate to approximately 2 to 2.5 volumes.
Extract with Grains Option:
Replace the American two-row and Munich malt with 3.3 lb (1 kg) of a blended Munich liquid malt extract and 4.5 lb (2 kg) of a pale or light liquid malt extract. Mill or coarsely crack the specialty malts. Mix them well and place loosely in a grain bag. Steep the bag in 1 gallon (~4 liters) of 170 °F (77 °C) water for about 30 minutes. Lift the grain bag out of the steeping liquid and rinse with warm water. Let the bag drip into the kettle while you add the malt extract. Do not squeeze the bags. Add enough water to the steeping liquor and malt extract to make a pre-boil kettle volume around 6.5 gallons (24.4 L) and the gravity is 1.050 (12.3 °P). Follow the remaining instructions for the all-grain recipe.