NOTE: In the 2015 BJCP Style Guidelines, Imperial IPA is now designated as Style 22A Double IPA in Category 22 Strong American Ale which includes modern American strong ales with a varying balance of malt and hops. The category is defined mostly by alcohol strength and a lack of roast.
The information below is still valid, but if you are studying for the current BJCP exam, use the current description in conjunction with this page as reference material.
An Imperial IPA, is a style American brewers came up with to satisfy their customer’s insatiable appetite for more and more hops in their beers. The term “Imperial” is taken from the Russian Imperial Stout, which was a very strong version of the popular English and Irish stout that was made for the Russian court and meant to withstand the long journey from England to Russia. Other terms are just as valid, Double or Triple IPA being the most popular. Some brewers test the physical limits of the properties of hops and add an insane amount in their recipes, vying for the most extremely drinkable example of the style.
The problem is that anyone can add a lot of hops to a recipe, but making a delicious Imperial IPA is much harder. Balancing the bracing bitterness and prodigious hop flavor and aromas with complex malt flavors is an art as well as a science. The first Double IPA is often attributed to Vinnie Cilurzo while at Blind Pig Brewery in Temecula, California. The story goes that he accidentally created Blind Pig IPA when he added 50% too much malt to the mash tun. To correct the mistake he balanced that by adding 100% more hops. The result was Blind Pig IPA, arguably the first Imperial IPA in America. The Blind Pig Brewery is closed now, but the Blind Pig IPA has attained cult status among beer affectionados. Vinnie has gone on to make other cult beers, such as Pliny the Elder. Others attribute the creation of the style to Rogue Ales with their I2PA, originally brewed in 1990. Whoever created the style, hopheads across the world have rejoiced for nearly two decades.
Brewing an Imperial IPA isn’t as easy as doubling an IPA recipe. You must brew a “drinkable” well balanced beer which is pretty difficult with the hop load in these beers. You have to keep the Crystal malt character down and make sure the beer finishes dry, otherwise the beer will end up tasting like an American Barleywine. A couple of things you can do to keep the finishing gravity low (thus the attenuation high) is to use a lower mash temperature, in the 149-150°F (65-65.6°C) range. You almost have to add sugar to the beer to get the final gravity to finish low, one to two pounds is about right per 6 gallons. The hop load in an Imperial IPA is usually so high that it doesn’t matter which bittering hop you choose. It is however very important which flavor and aroma hops you choose because these characters are “extreme” in these beers. American hops are most often used in these beers.
Double / Imperial IPA Description
- Aroma: Imperial IPAs have a prominent to intense hop aroma that can be derived from American, English and/or noble varieties (although a citrusy hop character is almost always present). Most versions are dry hopped and can have an additional resinous or grassy aroma, although this is not absolutely required. Some clean malty sweetness may be found in the background. Fruitiness, either from esters or hops, may also be detected in some versions, although a neutral fermentation character is typical. Some alcohol can usually be noted, but it should not have a “hot” character.
- Appearance: The color of an Imperial IPA ranges from golden amber to medium reddish copper and some versions can have an orange-ish tint. They should be clear, although unfiltered dry-hopped versions may be a bit hazy. Good head stand with off-white color should persist.
- Flavor: Hop flavor is strong and complex, and can reflect the use of American, English and/or noble hop varieties. High to absurdly high hop bitterness, although the malt backbone will generally support the strong hop character and provide the best balance. Malt flavor should be low to medium, and is generally clean and malty although some caramel or toasty flavors are acceptable at low levels. No diacetyl. Low fruitiness is acceptable but not required. A long, lingering bitterness is usually present in the aftertaste but should not be harsh. Medium-dry to dry finish. A clean, smooth alcohol flavor is usually present. Oak is inappropriate in this style. May be slightly sulfury, but most examples do not exhibit this character.
- Mouthfeel: Smooth, medium-light to medium body. No harsh hop-derived astringency, although moderate to medium-high carbonation can combine to render an overall dry sensation in the presence of malt sweetness. Smooth alcohol warming.
- Overall Impression: An intensely hoppy, very strong pale ale without the big maltiness and/or deeper malt flavors of an American barleywine. Strongly hopped, but clean, lacking harshness, and a tribute to historical IPAs. Drinkability is an important characteristic; this should not be a heavy, sipping beer. It should also not have much residual sweetness or a heavy character grain profile.
- Comments: Bigger than either an English or American IPA in both alcohol strength and overall hop level (bittering and finish). Less malty, lower body, less rich and a greater overall hop intensity than an American Barleywine. Typically not as high in gravity/alcohol as a barleywine, since high alcohol and malt tend to limit drinkability. A showcase for hops.
- History: A recent American innovation reflecting the trend of American craft brewers “pushing the envelope” to satisfy the need of hop aficionados for increasingly intense products. The adjective “Imperial” is arbitrary and simply implies a stronger version of an IPA; “double,” “extra,” “extreme,” or any other variety of adjectives would be equally valid.
- Ingredients: Pale ale malt (well-modified and suitable for single-temperature infusion mashing); can use a complex variety of hops (English, American, noble). American yeast that can give a clean or slightly fruity profile. Generally all-malt, but mashed at lower temperatures for high attenuation. Water character varies from soft to moderately sulfate.
- Vital Statistics: OG: 1.070 – 1.090 FG: 1.010 – 1.020 IBUs: 60 – 120 SRM: 8 – 15 ABV: 7.5 – 10%.
- Commercial Examples: Russian River Pliny the Elder, Three Floyd’s Dreadnaught, Avery Majaraja, Bell’s Hop Slam, Stone Ruination IPA, Great Divide Hercules Double IPA, Surly Furious, Rogue I2PA, Moylan’s Hopsickle Imperial India Pale Ale, Stoudt’s Double IPA, Dogfish Head 90-minute IPA, Victory Hop Wallop.
References: References: Information for this article was adapted from the 2008 BJCP Style Guidelines, and Brewing Classic Styles 80 Winning Recipes Anyone Can Brew, written by Jamil Zainasheff and John J. Palmer, the Brewing in Styles section of Brewing Techniques magazine entitled India Pale Ale, Part II: The Sun Never Sets– written by Thom Tomlinson, and the Wikipedia article entitled India Pale Ale.