I have a more-or-less annual tradition of making a pumpkin beer, and I was looking for something a bit different this time around. Although to be honest, I’m always looking for something different on pumpkin beers! Each brewing year brings something unique–for 2017, I’m doing a pumpkin imperial stout!
The recipe is patterned after a BYO clone recipe for Southern Tier’s Warlock Imperial Stout, in the September 2017 issue. I scaled it down from 5 gallons to 3 gallons, because I didn’t really want a massive quantity of a ~10% abv beer. To up the malt complexity, I subbed in Vienna malt for the recipe’s 2-row, and subbed Warrior in for Chinook hops. Because this is such a high gravity beer, I assumed 70% mash efficiency (which turned out to still be a bit high). My local shop didn’t have WLP022 (Essex Ale yeast) in stock, so I opted for Mangrove Jack’s M15 (Empire Ale).
Pumpkin Patch Imperial Stout
- 6.25 lbs. Vienna malt (Great Western)
- 5 lbs. 2-row pale malt (Rahr)
- 0.6 lb. flaked barley
- 0.5 lb. de-bittered black malt (Dingemans)
- 0.3 lb. caramel malt 60L (Briess)
- 0.25 lb. Munich II malt (Weyermann)
- 0.19 lb. chocolate malt (Briess)
- 0.15 lb. rice hulls
- 0.6 lb. pumpkin puree (homemade)
- 1 oz. Warrior hops (15.8% alpha), 60 minute boil
- 1 Whirlfloc tablet, 10 minute boil
- 1 tsp. Fermax yeast nutrient, 10 minute boil
- 1 pkg. Empire ale yeast (Mangrove Jack’s M15)
- Cinnamon, vanilla, nutmeg, and ginger extracts to taste (3:1 ratio of cinnamon to others)
- Infusion mash to hit target of 150°, 60 minutes. Batch sparge.
- Claremont tap water, with Campden tablet.
- 1.095 o.g., 1.022 f.g., 9.7% abv, 70.5 IBU, 38 SRM, 3 gallons into fermenter
- I mashed in with 4.4 gallons of water at 162°, to hit a mash temperature of 151.4°. Given the big bulk of grain, the mash temperature held pretty well for the full 60 minutes.
- After 60 minutes, I vorlaufed and collected the first runnings. I had a very slow run-off for this step.
- I then added 2.45 gallons of sparge water at 185°, let it sit for 10 minutes, and vorlaufed again. I did a gentler (slower) vorlauf, which seemed to help with the sparging issue.
- In total, I collected 4.9 gallons of water with a gravity of 1.065, for 67% mash efficiency. Given the high target gravity versus the volume of water, I’m not incredibly surprised. Nonetheless, I’ll want to remember to adjust efficiency accordingly for my next high gravity recipe.
- I brought the wort to a boil and added the various hops, etc., at the designated time. After 60 minutes, I turned off the heat and chilled the wort to around 80°. I transferred while aerating, and then pitched the yeast directly.
- Starting gravity was 1.085. I’ll be starting fermentation at 66°. I brewed the beer on 19 August 2017, and had visible yeast activity within 9 hours after pitching.
- After around two weeks, I’ll add the appropriate spice extracts. I plan to make these myself, using a vodka infusion. Although the original recipe calls for clove extract, I am going to leave that out, because (as I read once from Gordon Strong) clove is too often an off flavor and might detract from the overall taste on the final product.
Fermenting happily, ~12 hours after yeast pitching
Time to do the semi-annual brew of my world-famous recipe (by virtue of appearing in Zymurgy), Eagle Face Oatmeal Stout! This iteration has only small modifications, to account for my current mash efficiency (~75%), which means a slight reduction in the amount of base malt. I also changed the hops (to use up one of my high-alpha hops), which shouldn’t result in a substantive difference for the flavor profile because they’re really just for bittering anyhow. Finally, I toasted my oatmeal to try something a little different. The day before brewing, I set the oats in a 350° oven for 1.25 hours, which resulted in a nice toasty aroma and crispier oats with a slight golden edge on most of the flakes. We’ll see how that changes stuff (if it does).
Toasted oats, ready for the brew.
Eagle Face Oatmeal Stout 1.4
- 7.5 lbs. 2 row malt (Great Western)
- 1.5 lbs. old-fashioned oats (lightly toasted)
- 1 lb. 80° L crystal malt (Briess)
- 1 lb. Victory malt (Briess)
- 0.75 lb. chocolate malt (Briess)
- 0.5 lb. roasted barley (Bairds)
- 0.38 lb. rice hulls
- 1 Whirlfloc tablet, 10 minute boil
- 0.82 oz. Magnum hop pellets (13.2% alpha), 60 minute boil
- 1 pkg. English Ale yeast (White Labs WLP002, in starter)
- 156° mash, 60 minutes
- 1.061 o.g., 1.022 f.g., 5.1% abv, 37 IBU, 41 SRM, 5.5 gallons into the fermenter
- A few days in advance of the brew, I prepared a 2L starter. After two days on the stir plate, it was starting to flocculate out, and so I cold-crashed the starter. I split the starter into a 1.4L volume for pitching in this batch, and set aside 0.6L for a later brew.
- As with my most recent brewing session, I have modified my mash procedure slightly. I added the strike water directly to the unheated mash tun, and then added the malt after temperature stabilized at my desired strike point. In this case, I added 4.2 gallons of water at 180°. Once in the mash tun, the temperature dropped to 175°, a bit above my target of 168.7°. So, I let things sit until it matched my target, and then mashed in. For future reference, I should only overshoot my strike water temperature around 5° or so; this will result in a little bit shorter time to reach the planned temperature in the mash tun.
- My mash temperature settled at 154-156°, depending on where I measured it in the tun. It was down to 152° after 45 minutes. After 60 minutes, I added 0.75 gallons of water at 185°, let sit for 10 minutes, vorlaufed, and collected the first runnings. I then added another 3.5 gallons of water at 175°, which raised the mash bed to 160°. After sitting and vorlaufing, I collected the second runnings.
- In total, I collected 6.4 gallons of wort at a gravity of 1.052, for 76% mash efficiency.
- I started the boil, adding ingredients per the schedule. After 35 minutes of boiling, I added an additional 0.25 gallons of R.O. water, to bring up the boil volume slightly and drop the gravity slightly.
- After a 60 minute boil, I turned off the flame and started chilling. Once I got down to 70°, I transferred the wort (while aerating with the usual Venturi pump and wort sprayer) into my primary fermenter.
- My pre-fermentation volume was 5.25 gallons, up to 5.5 gallons (approximately) once I pitched the yeast.
- Starting gravity was 1.060, close enough to my target for me to be happy (anything within 0.001 is well within instrument measurement error)! I’ll be fermenting at 68°. This batch was brewed on 2 January 2017.