How To Brew an Imperial Stout (3 Recipes & Complete Style Guide!)

The Imperial Stout originated in England, but its come a long way as a style held closely to craft brewers’ hearts. This style uses select grains and hops, creating a dark and complex beer.

Brew an Imperial Stout with a combination of dark malts and bitter hops. Ale yeast strains create a few fruity esters, and the hop aroma is masked by roasted barley. These ingredients will create a black beer that’s full and rich with roasted coffee and chocolate notes. 

Get ready to make a killer Imperial Stout. Read on for a brief history as well as tips for choosing ingredients.

What is an Imperial Stout?

The stout is a relatively new style that only officially got its name in the 1800s. Until then, the word stout was used as a prefix to describe stronger versions of existing beer styles; most commonly, porters. Now, stouts are in a class of their own with quite a few substyles.

Stouts are some of the strongest types of beer on the market and have what might be the largest range of alcohol by volume of any style. The Imperial Stout has the highest ABV and with that comes other enhanced stout characteristics.

The Imperial Stout is a higher ABV, fuller and richer stout. It’s black in color with potent and bitter chocolate and coffee flavors from the roasted barley used. It was a rich roasted malt aroma with the bitterness coming from both hops and roasted malt ingredients.

  • Color – Black, 40+ SRM
  • Common flavor – Exceptionally rich. Roasted coffee and chocolate
  • Aroma – Roasted malt, chocolate, coffee
  • Mouthfeel – Full and smooth. Low carbonation.
  • IBUs (Bitterness) – 50-80
  • ABV – 7-12%
Imperial Stout Recipes and Brewing Guide

History of the Imperial Stout

London was famous for brewing porters, a beer named after blue-collar railroad and shipping dock workers who relied on it to warm them up after a long, often cold, day at work. The porter was adopted and adjusted throughout many years for many reasons, including changing laws and sheer demand.

The porter evolved into the stout, but not before it took the informal name of “stout porter.” A stout porter was a porter with a higher ABV and richness. In the 19th century, it was decided that stout porters differed too much from the original style, and the porter suffix was dropped. But that wasn’t before the coined Imperial Stout came to be.

The Imperial Stout started as a strong form of porter in London in the late 1700s. It eventually became popular in Russia and was heavily imported there from England. This style is commonly referred to as Russian Imperial Stout because it was a favored drink of Catherine the Great, the Russian Empress from 1762 to 1796.

Popular commercial Imperial Stouts

Here are a few Imperial Stout options for you to try: 

  • Great Divide Yeti – American Imperial Stout. High American hop bitterness. Roasted caramel and toffee notes.
  • Southern Tier Warlock – Imperial pumpkin stout with pumpkin spice flavors. Smooth and drawn-out roasted malt taste. 
  • Oskar Blues Tenfidy – Chocolate, caramel, and coffee notes. Brewed with flaked oats for a thicker mouthfeel. Malt and hop bitterness.
  • Epic Brewing Big Bad Baptist –  Chocolate and coffee flavors from cocoa nibs and coffee beans used for brewing. Each release uses different dark-roasted coffee.

Popular Imperial Stout recipes (all-grain or extract)

Imperial Stout - All Grain or Extract Beer Brewing Kit (5 Gallons)

A huge beer that features nearly 18 lbs of grain. Features Crystal, Chocolate, Roasted Barley and Black Patent.

This Imperial Stout recipe makes an excellent beer for sipping in front of the fire. Ages for a long, long time eventually gaining some Port like flavors.

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How to brew an Imperial Stout

Now that you know a bit about the history of the style, I’ll cover the different aspects of how to make an Imperial Stout. I will go step by step to dive into the ingredients and how they are used on brew day.

An Imperial Stout will take about a week to ferment with an additional resting period for bottled batches. The entire process can take up to 4 weeks, depending on the yeast strain and packaging method. If you bottle age, it can take up to six months.

Recipe and ingredients

Before you start brewing an Imperial Stout, you need to collect the proper ingredients. Imperial Stouts tend to stick to a stricter recipe list, but there’s some room for experimentation. Below are some tips and guidelines to get you started, but feel free to change a few things.

Water profile

A good water profile can turn any beer from good to great. Different water profiles enhance different aspects of beers, and some beer styles benefit from a particular water profile.

For an Imperial Stout, a good water profile uses a 5.4 pH level. Higher pH levels at 5.5 or 5.6 will help balance out some of the roasted malt flavors. Start with RO water and add minerals to get a relatively hard water profile.

For hoppier American styles, aim for a higher sulfate level to bring out more of the hop flavor and bitterness. Greater chloride levels will complement roasted malt additions.

Base grains

High-quality base grains are an important part of brewing any beer. Stouts get most of their flavor from specialty grains used, but base grains set the stage for other additions.

When selecting base grains for an Imperial Stout, any pale malt will suffice. Pale malts provide a clean foundation for specialty grains like roasted barley or black patent malt.

Although the flavor comes mostly from specialty grains, base grains will make up 80-90% of the grain bill, even for an Imperial Stout. These grains are easily fermented and can consist of one or two different types.

Base and specialty grains for Imperial Stouts

Specialty grains or other additions

As I mentioned earlier, specialty grains are the ones that shine in an Imperial Stout.

Imperial Stouts commonly use roasted barley as the lone specialty grain. They also make use of black patent malt for an even toastier, more bitter taste. These malts are where the chocolate and coffee notes come from, as well as a degree of bitterness.

If you want an Imperial Stout with more bitterness, use Black Patent Malt. For sweeter notes with more chocolate flavor, use Chocolate Malt. Pale Chocolate Malt is used for a balance between sweet and bitter.

Hops

Imperial Stouts make use of hops for both aroma and bitterness. This style can reach high IBUs, but the perceived bitterness is balanced by roasted notes.

Imperial Stouts feature a variety of hops but emphasize many British strains. They’re used for bittering, aroma and taste. This style commonly uses East Kent Golding and Horizon hops.

The most important aspect of hop selection is choosing varieties that complement each other. As you’ll see below, bittering hops have more to do with the bitterness of a beer whereas flavor and aroma hops are more responsible for the taste and smell.

Bittering

Bittering hops are used to add bitterness to beer. They’re added at the beginning of the boil allowing ample time for isomerization to occur. At the same time, the aromas of these hops are boiled away and the wort is left with a strong bitterness.

Because bittering hops don’t add much flavor or aroma to beer, it’s best to choose ones that have a high alpha acid content to maximize bittering efficiency during brewing. Although bittering hops aren’t responsible for flavoring, too much can cause the beer to taste vegetal.

Imperial Stouts have high IBUs and use hops with high alpha acid content. 

Here are some good bittering hops to use for an Imperial Stout.

NamePurposeAlpha Acid %
HorizonBittering + Aroma9-17%
SummitBittering16-18%
CascadeBittering + Aroma12-14%
GlacierBittering + Aroma3.3-9.7%
ColumbusBittering + Aroma14-18%
Best bittering hops for Imperial Stouts
Aroma and Flavor

Aroma and flavor hops are used for exactly that – aroma and flavor attributes.

Aroma and flavor hops are added late in the boil, usually past or at halfway mark. The more time they’re in the boil, the less flavor and aroma they give off. Imperial Stouts use aroma hops sparingly to mitigate conflicting flavors with grains, but late additions are common.

Not all flavor and aroma hops go together and the wrong combinations can create undesired flavors. If you’re going to use more than one aroma hop, try to pair varieties that complement each other.

NameFlavor/AromaAlpha Acid %
East Kent GoldingLavender, spice, honey5-6%
NuggetHerbal, earthy 9-14%
FuggleEarthy, floral2-6%
ChinookPiny, spicy12-14%
Best flavor and aroma hops for Imperial Stouts

Yeast

Yeast is vital for any beer style. Imperial Stouts have a decent pool to pick from.

Imperial Stout yeast strains should ferment clean with medium to high flocculation. At certain temperatures, these yeast strains can more or fewer fruity esters. Both are acceptable in the style.

Many English-origin styles use yeast strains with a lot of fruity esters. Most fruity esters in an Imperial Stout will be muted by roasted malt and hop notes.

Dry

Below are some good dry yeast options for an Imperial Stout.

NameAttenuationFlocculationTemp Range
Safale US-0578-82%Medium64.4-78.8°F
LalBrew Nottingham78-84%High50-72°F
Safale S-0474-82%Medium64.4-78.8°F
Best dry yeasts for Imperial Stouts
Liquid

Below are some good liquid yeast options for an Imperial Stout.

NameAttenuationFlocculationTemp Range
WLP007 English Ale 70-80%High65-70°F
WLP013 London Ale67-75%Medium66-71°F
OYL-005 Irish Ale69-75%Medium62-72°F
Best liquid yeasts for Imperial Stouts

Brewing process for Imperial Stouts

After you choose the ingredients for your Imperial Stout, it’s time to start your brew day!

First, decide on the type of mash you are going to do: single-step or infusion. For Imperial Stouts, a single-step mash is usually sufficient. You should also consider the mashing temperature, water quantities, hopping schedule, and if you need an additional fermenter.

The recipe you use will be your guide throughout the brewing process. The brew day will be fairly standard with minimal deviation from traditional methods along the way.

Start with the mash-in. Then, sparge. Once you collect enough wort, it’s on to the boil where you’ll add hops and any other adjuncts you or your recipe calls for. After that, it’s time to cool the wort, pitch the yeast and wait.

Brewing process for Imperial Stouts

Mashing

The mashing process for an Imperial Stout will take about 60 minutes.

A single infusion or single-step mash will work for an Imperial Stout. A step mash is also viable. Mash between 152-158°F for an Imperial Stout. Mashing at lower temperatures in that range will yield greater results for a high ABV target.

For an Imperial Stout, I recommend you mash at 153°F to produce enough easily fermentable sugars to achieve a higher ABV than you would at higher temperatures.

Use 1.1 quarts of water for each pound of grain used.

Boil

The boiling period can last anywhere from 60-90 minutes depending on the recipe. This allows enough time to invoke bitterness in the wort from the early hop additions. Your bittering hops will be added at the start of the boil. Aroma hops are used sparingly. Add those with less than 30 minutes left to the boil. 

Common times to add flavor and aroma hops are 30, 20, 10, and 5 minutes before the end of the boil. The longer these hops are in the boil, the more bitterness they will impart. Imperial Stouts have a high IBU with a little hop aroma that’s often masked by malt aromas.

Whirlpool or flameout

Hops can be added after the boil at flameout or what’s called the whirlpool.

Adding hops just after flameout or during whirlpool are similar methods, but slightly different. Both take place just after removing the boiling wort from the heat. As the wort cools you can add hops to get more aroma and flavor with little to no bittering.

The difference is evident in the whirlpooling method. Instead of just adding the hops to a cooling wort, you also create a whirlpool in the wort. This collects the trub while the hops add their flavor and aroma.

Fermenting Imperial Stouts

Fermentation is standard for an Imperial Stout.

All beer benefits from a consistent fermentation temperature. For most ale yeasts, which is what you will use for this style, it takes around one week.

Consistent fermentation temperatures will produce a higher-quality beer.

Temperatures

The temperature that you ferment at will depend on the strain of yeast you use.

For an Imperial Stout, keep the fermenter between 65 and 70°F. If your chosen yeast creates more esters than you want in this beer you can keep it on the lower end of its temperature range. Most esters in this style are masked by a roasted malt aroma.

Keeping the fermenter at a uniform temperature for the entire process will help your quality in the end.

Bottling or Kegging Imperial Stouts

Bottling or kegging is usually up to the person drinking it. However, Imperial Stouts might benefit from one over the other.

You don’t need to stick to one or the other for packaging an Imperial Stout. Although, some recipes call for a bottle-aging process that can enhance the aspects of the beer. In the end, choose a method that works best for you and your carbonation style.

Drinking Imperial Stout from a keg

Imperial Stout recipes

Imperial Stouts are a fun style to brew, as they make use of a few different hop varieties and combine plenty of grains. Here’s a list of three all-grain recipes, each brewing five-gallon batches:

  • Brooklyn Brewery’s Black Ops Clone – Brew Your Own
  • Imperial Stout – MoreBeer!
  • Russian Imperial Stout – Joe Postma

Brooklyn Brewery Black Ops Clone

Ingredients

  • 2-Row Pale Malt – 15 lbs.
  • British Crystal Malt (77 °L) – 1.25 lbs 
  • Black Malt – 0.5 lbs
  • British Chocolate Malt – 0.5 lbs
  • Roasted Barley – 0.25 lbs 
  • Demerara Sugar – 1 lb
  • Summit hops – 0.5 oz
  • East Kent Golding hops -1.5 oz 
  • Yeast of your choice. Suggested: Wyeast 1968, White Labs WLP002, or Lallemand London ESB Ale yeast
  • White Oak bourbon barrel or 1 oz. American Oak chips
  • Bourbon

Instructions

  1. Set up all-grain brewing equipment.
  2. Heat 4.8 gallons of water to 152°F
  3. Slowly add the 2-Row, British Crystal, Black Malt, British Chocolate malts, and roasted barley to the heated water in the mash tun. Stir while adding
  4. Mash at 152°F for 60 minutes
  5. After the mash, recirculate the wort until the runoff is mostly clear
  6. Sparge with 170°F water for 45-60 minutes. Collect 6-7 gallons for the boil
  7. Begin the 60-minute boil. Add Summit hops
  8. At flameout, add the East Kent Golding hops
  9. Cool the wort to pitching temperatures for chosen strain
  10. Pitch yeast, and aerate
  11. Ferment at 66°F for one week
  12. Raise heat to 70°F until fermentation is complete

For the barrel-aged version:

  1. Soak 1 oz. American Oak chips for two weeks before the aging process
  2. Rack beer into a secondary fermenter
  3. Add 1 oz. bourbon-soaked American Oak chips
  4. Let sit for at least six months
  1. Prime your beer for bottle conditioning. Carbonation can take 2 weeks
  2. Bottle your beer
  3. Carbonate your beer
  4. Once carbonation is done, enjoy your beer!

Imperial Stout from MoreBeer!

Ingredients

  • American 2-Row Malt – 15 lbs  
  • Carapils – 1 lb 
  • Crystal 40°L – 1 lb 
  • Roasted Barley – 0.5 lb
  • Black Patent – 6 oz/0.375 lbs
  • Chocolate Malt – 6 oz/0.375 lbs
  • Magnum hops – 2 oz 
  • Cascade hops – 2 oz 
  • Clarifier – Boil last 5 min
  • Yeast of your choice. Suggested: WLP007 Dry English, Wyeast 1098 British, Imperial A10 Darkness, Omega OYL006 British Ale I, CellarScience Dry ENGLISH,  Safale S-04

Instructions

  1. Set up all-grain brewing equipment.
  2. Heat 4.5 gallons of water to 153°F.
  3. Slowly add the 2-Row, Carapils, Crystal, Back Patent, Chocolate malts, and Roasted Barley to the heated water in the mash/lauter tun. Stir while adding.
  4. Mash at 153°F for 60 minutes.
  5. After the mash, recirculate the wort until the runoff is mostly clear.
  6. Sparge with 170°F water for 45-60 minutes. Collect 6-7 gallons for the boil.
  7. Begin the 60-minute boil. Add the 2 oz of Magnum hops.
  8. At 5 minutes left on the boil, add 2 oz of Cascade hops and the clarifier.
  9. Cool the wort to pitching temperatures for chosen strain.
  10. Pitch yeast.
  11. Ferment between 68-70°F for at least one week.
  12. Allow one week for settling.
  13. Bottle or keg as desired.
  14. Carbonate your beer.
    1. If bottling, prime your beer for bottle conditioning. Carbonation can take 2 weeks.
    2. If kegging, force carbonate.
  15. Once carbonation is done, enjoy your beer!

Russian Imperial Stout from Serious Eats

Ingredients

  • 2-row pale malt – 17 lbs
  • Chocolate malt – 1 lb 
  • Roasted barley – 1 lb
  • Flaked oats – 1 lb
  • Black patent malt – 0.5 lb
  • Crystal 120 malt – 0.5 lbs
  • Galena hops – 2 oz 
  • Northern Brewer hops – 2 oz 
  • Yeast of your choice. Suggested: WLP007 or Wyeast 1098

Instructions

  1. Set up all-grain brewing equipment
  2. Heat 5.5 gallons of water to 154°F
  3. Slowly add the 2-Row, chocolate, black patent, and crystal malts, roasted barley, and flaked oats to the heated water in the mash/lauter tun. Stir while adding
  4. Mash at 154°F for 60 minutes
  5. After the mash, recirculate the wort until the runoff is mostly clear
  6. Sparge with 170°F water for 45-60 minutes. Collect 6-7 gallons for the boil
  7. Begin the 90-minute boil. Add 2 oz of Galena hops.
  8. At 30 minutes left on the boil, add 1 oz of Northern Brewer hops
  9. At 10 minutes left on the boil, add 1 oz of Northern Brewer hops
  10. Cool the wort to pitching temperatures for chosen strain
  11. Pitch yeast
  12. Ferment at 65°F for three weeks.
  13. Allow one week for settling, or transfer to secondary carboy and age for 3-6 weeks
  14. Bottle or keg as desired
  15. Carbonate your beer
    1. If bottling, prime your beer for bottle conditioning. Carbonation can take 2 weeks
    2. If kegging, force carbonate
  16. Once carbonation is done, enjoy your beer!

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