Imperial Pumpkin Stout Recipe

[FswBG]

Hello,
I am planning to brew an imperial pumpkin stout next weekend to have ready this winter. I haven't done a high grav stout in a few years so I'm taking a stab at a recipe I hodge-podged from a few different sources. Since I'll be incorporating a few new tweaks to my process and this will take several months to finish, I would appreciate everyone's thoughts on my plan. I'm looking for something that has some complexity, but isn't too sweet or too bitter. I also don't want the pumpkin or other spices to overwhelm the beer.


P.imp stout
Imperial Stout
10.0% / 24.8 °P
All Grain
Unibrau EBIAB
65% efficiency
Batch Volume: 6 gal (Kettle)
Fermenter Volume: 5.26 gal
Boil Time: 90 min
Mash Water: 7.93 gal
Sparge Water: 1.92 gal
Total Water: 9.85 gal
Boil Volume: 7.5 gal
Pre-Boil Gravity: 1.084
Vitals
Original Gravity: 1.105
Final Gravity: 1.029
IBU (Tinseth): 54
Color: 33 SRM


Mash

Temperature — 152.6 °F — 60 min
Malts (24 lb 8 oz)
21 lb (82.4%) — Briess Brewers Malt 2-Row — Grain — 1.8 SRM
1 lb (3.9%) — Briess Barley, Flaked — Grain — 1.7 SRM
1 lb (3.9%) — Weyermann Munich I — Grain — 7.1 SRM
12 oz (2.9%) — Black (Patent) Malt — Grain — 500 SRM
8 oz (2%) — Caramel/Crystal Malt — Grain — 60 SRM
4 oz (1%) — Thomas Fawcett Pale Chocolate — Grain — 305 SRM
Other (1 lb)
1 lb (3.9%) — Pumpkin Puree — Adjunct — 2 SRM — Mash
Hops (3.5 oz)
1.5 oz (44 IBU) — Columbus/Tomahawk/Zeus (CTZ) 13.7% — Boil — 60 min
2 oz (10 IBU) — East Kent Goldings (EKG) 4% — Boil — 20 min
Miscs
0.56 g — Calcium Chloride (CaCl2) — Mash
1.48 g — Gypsum (CaSO4) — Mash
60 ml — Phosphoric Acid 10% — Mash
0.11 g — Calcium Chloride (CaCl2) — Sparge
0.28 g — Gypsum (CaSO4) — Sparge
Yeast
5 pkg — Wyeast Labs 1335 British Ale II
5 L starter
18.84 oz DME / 23 oz LME
12343 billion yeast cells
2.5 million cells / ml / °P
Fermentation
Primary — 66 °F — 14 days
Conditioning — 60 °F — 100 days
Carbonation: 2.4 CO2-vol
Water Profile
Ca+2 - 44
Mg+2 - 8
Na+ - 5
Cl- 16
SO4-2 - 46
HCO3- 87
Add to Secondary
nutmeg, cinnamon, vanilla bean, brown sugar - To taste

A few questions I have:
1. Since it's so high grav should I hit it with O2 again after 12 hours of pitching? I haven't done this before so just looking for some perspective from someone who has.
2. Any suggestions on how many vanilla beans I should use in secondary? Again, I don't want it to be too sweet. I'd like to shoot for subtle notes of these adjuncts.
3. This will be my biggest starter to date. I have made 5L before, but not adding 5 packs to the mix. Ideally I would like a FG in the low 1030s. I'm nervous to under pitch with such high-abv. Any suggestions on how to keep from over attenuating?

 

[hoya]

If you have a good enough oxygen setup, then one dose of oxygen should be enough, as long as it is big enough. I have found that 2 minutes at ~5psi gauge from a welding tank is more than sufficient.

For a starter, 5 liters is enormous for the batch size you are using, and something I would only really recommend for much larger beers. I would say that a ~3.5l starter would work just fine, assuming of course that you oxygenate enough. I highly doubt you will over-attenuate with that size of a starter. Worst comes to worst, you can add some dextrose to the secondary to hit your FG. Also, I doubt you would need 5 packs, unless your yeast is old. I have had no issues with using a single pack/vial for 3l+ starters.

As far as vanilla goes, I wish I could tell you. I have an Avery Rumpkin clone in the primary right now, and I am adding 5 beans soaked in rum to a total of 10 gallons. For 5 gallons, and on a less strong beer, I can't imagine needing more than two whole beans.

Final thing -- you may want to up the pumpkin in your recipe. For a 5+ gallon batch, using a large (30oz) is prudent. I use 9 lbs of fresh pumpkin per 5 gallons for my 5% pumpkin pie beer.

 

[Jag75]

Didn't have luck with my pumpkin stout , hopefully yours turns out good . BTW love the name of your stout . Very clever

 

[FswBG]

If you have a good enough oxygen setup, then one dose of oxygen should be enough, as long as it is big enough. I have found that 2 minutes at ~5psi gauge from a welding tank is more than sufficient.

For a starter, 5 liters is enormous for the batch size you are using, and something I would only really recommend for much larger beers. I would say that a ~3.5l starter would work just fine, assuming of course that you oxygenate enough. I highly doubt you will over-attenuate with that size of a starter. Worst comes to worst, you can add some dextrose to the secondary to hit your FG. Also, I doubt you would need 5 packs, unless your yeast is old. I have had no issues with using a single pack/vial for 3l+ starters.

As far as vanilla goes, I wish I could tell you. I have an Avery Rumpkin clone in the primary right now, and I am adding 5 beans soaked in rum to a total of 10 gallons. For 5 gallons, and on a less strong beer, I can't imagine needing more than two whole beans.

Final thing -- you may want to up the pumpkin in your recipe. For a 5+ gallon batch, using a large (30oz) is prudent. I use 9 lbs of fresh pumpkin per 5 gallons for my 5% pumpkin pie beer.

Thanks for the suggestions. I do oxygenate and have a regulator that'll let me set the flow. I have just always heard pure oxygen is toxic to yeast. I know a lot of people burst again on big beers.. I suppose I was just looking for some assurance or rdwahahb.

I have been doing some more reading on vanilla beans and I'm finding making a tincture and adding to a sample of the fermented beer will help me scale how much to add. I'm interested to hear how the Rumpkin clone comes out! That is my wife's favorite fall/winter beer.

As far as the pumpkin, I will take your advice and up the amount for the recipe. I think I have also decided to add it in the last 10m of the boil instead of mashing. It seems anecdotally to provide more flavor that way. Unfortunately pumpkins aren't quite in season yet so puree' it is!