17 October 2017 Published in Haas Style Blog

I have been out and about lately talking about beer to people I meet. One thing keeps coming up in conversation over and over again: IBUs.  That’s right IBUs.  What are IBUs and how are they used?  Well let’s get into that.

IBU stands for International Bitterness Units. The International Bittering Units scale, or simply IBU scale, is used to approximately quantify the bitterness of beer. This scale is not measured on the perceived bitterness of the beer, but rather the amount of iso-alpha acids.  These iso-alpha acids contribute to the bitter flavors in beer, which come from hops.  So the more IBUs the more hoppiness?  NO. There is no scale for hoppiness in beer.  And IBUs aren’t a measure of bitterness in beer either, only relative betterness.

Though the IBU scale can be used as a general guideline for taste, with lower IBUs corresponding to less bitterness and vice versa, it's important to note that malt and other flavors can mask the taste of bitterness in beer.  As we add more malt flavor to the beer, more of the hop bitterness is masked.  There is a balance we are trying to achieve and bitterness is one component of that balance. Unabbreviated and unexplained, IBUs are little more than a number for the consumer to sink their teeth into.  The IBU scale does not take into account the other factors that contribute to the amount of perceived bitterness you taste in a beer.

IBUs in beer range from 5-2500.  That 2500 is a crazy number, brought to you by Flying Monkeys Brewery.  The human palate can only perceive bitterness up to 110 IBUs before it all tastes the same. Most beer is between 5 and 150 IBUs.  Once again though the more alcohol and/or sweet malt flavor, the less you will perceive the IBUs.

This is the reason I don’t use, nor promote, or like the use of IBUs. The scale is not a comparison between two beers, but rather a tool to use for any one specific beer.  You could have a beer with higher IBUs that doesn’t taste as bitter as a beer with a lower IBU count. This is the dilemma of using the IBU scale.  In addition, IBUs are definitely not a scale to judge the hop flavor of beer, no correlation. You add more hops to get a higher IBU count, but you are extracting the bitterness at that point and boiling off the hop flavored characters in the process.  Those flavors come later in the process.  

Wow. For someone who doesn’t like IBUs to be talked about, I just talked about them for a long time.  What does that say about the state of brewing in America?  I don’t know but I am going to ponder that thought over a nice balanced beer.  You do the same.