The Brewer

Imperial Stout Brewing Guide: The Tsar of Beers

Imperial Stout: Go Big or Go Home

The Russian Imperial Stout (RIS) is the ultimate test of a homebrewing system. With an Original Gravity (OG) often exceeding 1.100, this style pushes your mash tun, your boil kettle, and your yeast to the absolute limit. The goal is a pitch-black, viscous, complex beer that tastes of dark chocolate, espresso, dried fruit, and warming alcohol.

1. The Challenge: Efficiency

When you fill a mash tun to the brim with grain, your efficiency drops like a stone.

  • The Problem: You can’t sparge effectively because you don’t have enough water volume to rinse the sugars out without diluting the wort too much.
  • The Solution:
    • Double Mash (Reiterated Mashing): Mash half your grain, collect the wort. Then use that wort as the strike water for the second half of the grain. It takes all day, but you can hit 1.120 gravity easily.
    • DME Supplement: The cheater’s method. Mash as normal, then add 3-4 lbs of Dry Malt Extract (DME) to the boil.

2. Ingredients

The Malt: Layering

You cannot just use “Roasted Barley” and call it a day. You need depth.

  • Base: Pale Ale Malt (Maris Otter) is preferred for its nutty background.
  • Roast: A mix is essential.
    • Roasted Barley: Sharp coffee (5-8%).
    • Chocolate Malt: Rich dark chocolate (5%).
    • Pale Chocolate: Lighter, milk chocolate/nutty notes (3%).
  • Body Builders: Flaked Oats or Flaked Barley (10%) add the oily viscosity.
  • Sweetness: Crystal 80L or 120L (5-8%) provides the dark fruit/toffee backbone.

The Hops

  • Bitterness: You need huge bitterness (60-90 IBU) just to balance the malt sweetness. You won’t perceive it as “bitter,” just “balanced.”
  • Variety: High alpha American (Chinook/Magnum) or English (Target).

The Yeast

  • Alcohol Tolerance: This is non-negotiable.
  • Strains: US-05 (safe), WLP090 (San Diego Super - fast), or Wyeast 1056. English strains (S-04) can work but might quit early, leaving it cloying.
  • Pitch Rate: Pitch a massive starter. Or pitch onto the yeast cake of a previous batch of Pale Ale.

3. Recipe: “Ivan the Terrible” RIS

  • Batch Size: 5 Gallons (19 Liters)
  • OG: 1.100
  • FG: 1.025
  • ABV: 10.0%
  • IBU: 75
  • SRM: 60

Grain Bill

  • 7.3 kg (16 lbs) Maris Otter
  • 0.45 kg (1 lb) Roasted Barley
  • 0.45 kg (1 lb) Chocolate Malt
  • 0.45 kg (1 lb) Crystal 120L
  • 0.45 kg (1 lb) Flaked Oats

Hops

  • 60g (2 oz) Magnum (14% AA) @ 60 min
  • 30g (1 oz) East Kent Goldings (5% AA) @ 10 min

Yeast

  • 2 packets of US-05 or a 2L Starter of WLP001.

Instructions

  1. Mash: 66°C (151°F) for 75 minutes. Stir well; it will be thick.
  2. Boil: 120 Minutes. A long boil caramelizes the wort and concentrates the gravity.
  3. Ferment: 18°C (64°F). Be prepared for a blow-off tube! The fermentation will be explosive.
  4. Oxygen: Oxygenate the wort heavily before pitching.

4. Aging

Do not drink this beer fresh.

  • 3 Months: It will taste like burning alcohol.
  • 6 Months: The flavors start to merge.
  • 12 Months: The “umami” / soy sauce / port wine notes appear. This is the sweet spot.
  • Wood: Add oak cubes soaked in Bourbon for 2 months to simulate barrel aging.

Conclusion

An Imperial Stout is not just a beer; it is an investment in time. Brew it today, drink it next year.