Can You Homebrew a Zero IBU IPA?

By John Moorhead, AHA Competition Coordinator

What’s happening to bitterness in IPAs? The taste buds are tired, and they want a reversal of the Lupulin Threshold Shift. So some brewers are abandoning the ever-expanding ceiling of the “bitterest IPA ever” competition and putting their efforts elsewhere.

The goal, loosely based around adding all hops post boil, is a unique and controversial one because it goes against the status-quo of what makes an IPA an IPA—hopped throughout the boil to give a noticeable bite of bitterness.

What is an International Bittering Unit?

The International Bittering Unit (IBU) is a measurement of a beer’s bitterness (specifically, 1 IBU is 1 mg of isohumulone dissolved in 1 liter of beer). A hop-forward style like American IPA can have a bitterness level up to 70 IBUs, while a more malt-dominant style like English brown ale might only have 20 IBUs. These days, you might see beers claiming to have 100+ IBUs!

(FIND: Beer, Mead, and Cider Recipes)

The main source of bitterness is hops, which are boiled in order to unlock and dissolve the alpha acids through a process called isomerization. The resulting isohumulones are what your palate detects when you perceive bitterness in beer. However, since these bittering hop additions are boiled for 60 to 90 minutes to allow for isomerization, a lot of the flavor and aroma of the hop are lost. Hop additions later in the boil (or after the boil entirely) are used to add more flavor and aroma while imparting minimal IBUs since they are not boiled for long. This leads to the homebrewer’s rule of thumb that hops added early in the boil are “bittering hops” and additions later in the boil are “flavor and aroma hops.”

With this rule of thumb in mind, the insurgence of “no IBU” IPAs is based around the idea that all hop additions are added post-boil. In other words, these beer recipes are brewed using only flavor and aroma hop additions typically added towards the end of the boil or as post-fermentation dry hops.

Cerebral Brewing Co. Alternative Facts IPA

By Sean Buchan, Owner/Head Brewer of Cerebral Brewing

For 5 gallons (19 L):

  • OG: 1.063
  • FG: 1.005
  • ABV: 7.6%


  • 8.5 lb Pilsner
  • 2.75 lb Oat Malt
  • 0.50 lb White Wheat
  • 0.50 lb Dextrine
  • 0.15 lb Acidulated Malt
  • 0.50 lb Dextrose
  • 4 oz (112 g) Citra pellet hops (Whirlpool)
  • 3 oz (84 g) Citra pellet hops, Dry hop (Day 4)
  • 3 oz (84 g) Azacca pellet hops, Dry hop (Day 4)
  • 2 oz (56 g) Citra pellet hops, Dry hop (After terminal gravity)
  • 2 oz (56 g) Azacca pellet hops, Dry hop (After terminal gravity)
  • Blend of Conan and Sacch Trois yeast


Mash at 152° F (66° C). Boil for 75 minutes.

Post-Boil Hop Additions

There are three main post-boil hop additions to think about while making a zero IBU IPA: knockout, whirlpool, and dry hopping.

Knockout – When hops are added during the final minutes of the boil, fewer of the aromatic oils are lost to evaporation and more hop aroma is retained. This stage usually includes 1 to 2 ounces in a 5-gallon batch (28 to 57 grams in 19 liters). The added hops steep in the wort before being cooled down.

Whirlpool – Similar to knockout, whirlpool refers specifically to a strategy to transfer wort into a fermentation vessel that is meant to leave behind most of the trub. Stirring the wort in one direction quickly and allowing the wort to settle before transferring will leave a significant amount of solids behind. Add the hops just before beginning to create the whirlpool. This is shorter and cooler than the knockout. Stir for 1 to 2 minutes, then let it rest for 20 minutes.

Dry Hopping – Hops can be added to the fermenter for increased hop aroma. This is usually done late in fermentation to allow volatile oils to diffuse into the beer. Once the bubbling has stopped or slowed, add the hops. If hops are added while fermentation is still active, the aroma will be carried out by carbon dioxide.

Is a Zero-IBU IPA Actually an IPA?

Technically speaking, the zero-IBU IPA doesn’t fall into an official style. The Brewers Association Style Guidelines describe an American-Style IPA as having chill haze at cold temperatures and hop haze at any temperature. Fruity-ester aroma and hop aroma can be high, with hop bitterness medium-high to very high.

The Beer Judge Certification Program Beer Style Guidelines are similar. The style guide describes American IPA as decidedly hoppy and bitter, showcasing modern American or New World hop varieties. Unfiltered dry-hopped versions may be a bit hazy.

(READ: Tips on Brewing New England IPA)

Putting guidelines aside, the IPA has changed over time, and just like West Coast IPA wasn’t a style until somebody called it a West Coast IPA and the black IPA wasn’t a style until somebody called it a black IPA, the zero-IBU IPA could become a style one day. Time will tell.

The overall profile of a zero IBU IPA is different than your traditional IPA. It’s going to taste juicy and citrusy, with a smooth mouthfeel, but it will still intensely accentuate hop aroma and flavor. Some perceived bitterness will be present, but it is intentionally brewed to give you hop flavors and aromas.

If the zero-IBU IPA tastes favorable to the consumer, then so be it! Beauty (and good beer) is in the eye of the beholder (err, pint holder), and we should be willing to accept fresh takes on established styles as a means to express ourselves and our creativity.

John Moorhead, AHA Competition Coordinator, lives in Boulder, Colorado. If he isn’t tasting, brewing, or talking beer, you’ll see him running, roaming or biking around the mountains – or cooking Thai food and blasting vinyl. Occasionally, John will write about homebrewing happenings, and if he plays his cards right, they might show up here on

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