Recipe Critique -- Imperial Stout

2.5 gallon batch. I will likely brew with 1084 using 200 ml of slurry from a porter (or maybe a baby coffee stout I prime with sugary cold brew...!) of some sort bottled the day of. Open to suggestions on yeast, but I like 1084's performance in the 3 beers I've brewed with it so far.

• 62% Golden Promise (6.5 pounds)
• 5% Chocolate 350 (.5 pound)
• 5% Briess Caramel Rye 60L (.5 pound)
• 5% Roasted Barley (.5 pound)
• 5% Victory (.5 pound)
• 5% Crystal 120 (.5 pound)
• 5% Special B (.5 pound)
• 10% D-180 Syrup (1 pound)

• 1 oz Magnum at 60
• 1 oz each Cascade/Centennial at 5

90 minute mash at 152, 75 minute boil leads to:

• OG: 1.110
• FG: 1.024
• ABV:11.3%
• IBUs: 83 IBUs

I've brewed one imperial stout before and it turned out pretty well, including getting my usual 74% efficiency, so I'm fairly confident I will hit the numbers above. The first one was 75% 2-row, 8% chocolate 350, 5% roasted barley, 5% special B, 4% flaked oats and 3% golden naked oats, and it had a strong roast up front and smoothed out to some caramel sweetness/raisin/plum in the past year, so I would say I'm looking for more depth from the malts. Trying to trend closer to Bell's Expedition stout, and mine lacked the same depth/intensity of flavor. And a little sweetness. I'm also thinking:

• the Crystal 120/Special B are redundant and might be better off if I drop one and add more Chocolate 350 or Victory for some more malt depth (would likely drop the Special B)
• the D-180 is for ABV boost to deal with BIAB mash capacity limits/also for fun, but maybe excessive. If I want to get more ABV, probably better to drop a pound of dextrose/DME at 10 minutes left in the boil, but am curious as to everyone's input on using the syrup

Ferment at 62-64, raise to 70 after a week or so, depending on the SG reading at the time. What does everyone think?

 

Many thanks to everyone for their input, a lot of good guidance and suggestions. Taking into account everyone's notes on too much caramel, possible shadowing of Victory/muddled notes, and the suggestion for Munich, I've switched things up a little on the malt bill:

• 66.7% Golden Promise (7 pounds)
• 9.5% Dark Munich 15L (1 pound)
• 4.8% Chocolate 350 (.5 pound)
• 4.8% Roasted Barley (.5 pound)
• 2.4% Crystal 120 (.25 pound)
• 2.4% Briess Caramel Rye 60L (.25 pound)
  
• 9.5% D-180 Syrup (1 pound)

That seems a little more reasonable in my mind - I was worried I was including too many different malts. Am still not decided on the D-180 -- I may let the brewing spirits move me when I'm at the LHBS between it and dextrose/table sugar. Would you all keep the Caramel Rye at this point or just drop it?

 

One more question -- when reusing fresh yeast slurry, any need to oxygenate the wort before pitching? Going to bottle the coffee stout as the stout is mashing and then harvest whatever mL of slurry BrewCipher tells me to in a sanitized jar and put it in the fridge until the stout is ready for pitching.

 

Interesting. I've noticed stronger fermentations since I started oxygenating even my 2.5 gallon batches, so it's interesting to read you say it's not necessary. I know you're a big proponent of research -- do you have any related links about aeration/oxygenation?

 

Oh yeah right on, I didn't think you meant not to aerate. Was just wondering if you had any research on the necessity/benefit of oxygenating above and beyond aerating. I'm sure it's quite limited as studies tend to focus on batches bigger than 2.5-5 gallons, but you always seem to have a study up your sleeve in discussions like this.