Imperial stout has always been big and bold, but in recent years it’s been getting even bigger and bolder. Brewers are pushing the envelope on starting gravities—going higher, going thicker, and winding up with beers that remain extremely full-bodied even after fermentation. Weight and texture have become as important to the style as its complex malt flavors and compatibility with adjuncts and barrel-aging.
Here’s the thing: There’s no reason extract brewers can’t do the same at home. In fact, we may be uniquely well suited for it, as extracts eliminate the need for gigantic mash tuns or double mashes. Consider that many pro brewers are using malt extracts to help them hit those extra-high gravities. There’s no reason for extracts to hold us back from getting that big body and mouthfeel, especially when we steep some well-chosen specialty grains.
Let’s break the style down—a bit of background, some discussion of ingredients, and then some tips on brewing these impressive beasts at home using extracts with specialty grains.
Bourbon-barrel-aging and dessert-like adjuncts have helped to keep imperial stout fashionable, but the style has a long heritage—The Oxford Companion to Beer goes so far as to call it a “history lesson in a bottle.” Its roots are as an “extra-stout” porter brewed for export from England to the Baltics and Russia more than 200 years ago.
The story goes that Russian ruler Peter the Great gained an early appreciation for London porter on his travels there, and his successor Catherine the Great—who ruled from 1762 to 1796—also had a taste for it. Thrale’s Anchor Brewery in Southwark, London, exported a specially brewed stout—“imperial” because it was for the imperial Russian court—in the 1780s.
Craft brewers in North America, Great Britain, and elsewhere have revived and revitalized the style. If traditional British versions embrace balance and malt complexity, American ones tend to have more expressive hop bitterness and higher ABV. One of the best-known examples, whose name nods to the Russian story, is Old Rasputin from North Coast Brewing (Fort Bragg, California).
Imperial stouts keep well, and the alcohol is big—from 8 to 12 percent ABV and beyond. The flavor should be rich, exhibiting notes that might include dark fruits, coffee, chocolate, roast, and caramel. The body is full and chewy on the palate. An imperial stout is one to be savored through those dark days and long nights of winter. It’s an excellent beer for sharing, which is what I love to do while camping with friends.
Brewing High-Gravity Stouts with Extracts
You can brew imperial stout quite successfully using extracts and specialty grains. Fair warning: The grain bill for steeping is big and varied, but this is absolutely necessary to achieve that complex malt character. The specialty grains bring those alluring aromas and flavors such as rich dark cocoa, fresh-ground coffee, and dark stone fruits (think raisins, plums, and prunes). There is no need to make this an oatmeal stout—but if you must, limit it to a half-pound (227 grams) or so of flaked oats.
The key to brewing an imperial stout—or any big beer, really—is to avoid ending up with one that is overly sweet or syrupy, or one that is harsh in alcohol. Few things are harder to drink than a sweet, hot, alcoholic mess. Proper attenuation is critical to avoid the sweetness, and that means paying attention to yeast choice and healthy fermentation.
Another useful ingredient is time—longer maturation can help temper the warming alcohol and smooth out the edges. I like to think about my favorite whiskeys—the ones that sit in barrels for years, mellowing the alcohol and taking up myriad flavors over time. Apply this same thought process to imperial stout. Some of the finest examples are often at their best when they are two to three years old. That’s something to think about when it comes times for packaging—22-ounce bomber bottles still work well here.
Hops are typically English, but American ones work, too. The key is to remember this isn’t a beer style that highlights hops; the emphasis is on the complexity of malt flavors, but that should be balanced by the hop bitterness. If American hops are what you have, choose a high-alpha one such as Warrior or CTZ for balancing bitterness, and perhaps Cascade or Ekuanot for later additions. Remember: This is an imperial stout, not an American stout or black IPA. No need to dry hop.
Yeast should be relatively clean and neutral; English or American ale strains work well here. Personally, I love a London ale strain (such as White Labs WLP013 London Ale) or a clean California strain (such as White Labs WLP001 California Ale). Dry yeast in sufficient quantity also is an excellent option if you can’t (or don’t want to) prepare a yeast starter. However, you need plenty of healthy yeast to ensure a thorough fermentation—so use a pitching calculator to help (you can find a handy yeast pitch-rate calculator at beerandbrewing.com/tools/pitch-rate-calculator).
A relatively cool fermentation around 64–66°F (18–19°C) is ideal, as allowing it to go too high can lead to some unwanted buttery (diacetyl) flavors. Be patient; a long fermentation of anywhere from three weeks to a month is not uncommon. This is not a beer to rush—everything about it gets better with time. Low and slow is the name of the game.
And hey! Packaging is fun. This is a special beer—get creative with your imperial stout. Bombers or half-liter bottles work nicely. I know some who cork and cage, but it isn’t necessary. Naming these can be “great” fun, too. (See what I did there?) [Insert your name] the Great is always an option, or some Russian historical reference. This is a beer that presents beautifully as a gift, and brewing in early fall for a winter present is nice—it beats fruitcake any day of the week.
Patience is not a virtue but a miracle. Let this beer sit—it gets so much better with age. Vinous notes and luscious textures develop over time. Again, think of your favorite wines and brown spirits and why you enjoy them so much. Time can work wonders in developing dark-fruit notes, the complex mingling of roast, coffee, and even port-like flavors—a deep beer gets even deeper and more beautiful, especially if you’re starting out bigger and bolder from the outset.