IBUs: Don’t Fall for the Numbers Trap

The world of craft beer is wonderfully complex. The sheer amount of possible ingredients and different brewing techniques means an almost limitless variety of flavors in our beer for us to taste and compare and enjoy. It’s understandable that we may develop “rules” for ourselves in order to help narrow our focus when faced with a selection of unfamiliar craft beers. For some it may be color (“I only really like ambers”) or type (“Lagers are best”), while for others it may be a combination of color and ABV or other characteristics.

One common guideline that people often use is the number of IBU’s in a beer. While the International Bittering Units (IBU) scale does serve as a useful tool when comparing beers, the drinker does themselves a disservice when they refuse to try beers outside their “ideal” IBU range.

Generally, all beers feature bitterness in their flavor profile. Where does this bitterness come from? For most beers, bitterness comes from the alpha acids in hops that are activated (a chemical process known as isomerization) when the hops are boiled in the wort.

Different hops have different levels of alpha acids, which is why brewers select specific hops to achieve a particular beer profile. Bittering hop varieties such as Chinook and Tomahawk, which are typically added early in the boil, range from 10-20% alpha acids. Aroma hop varieties, which are typically added late in the boil, will often have lower alpha acids present in most cases. How long the hops are boiled in the wort matters too, with longer boiling periods releasing more alpha acids from the hops.

The IBU scale, then, measures the parts per million of alpha acids present in any given beer. It does not, however, describe the perceived bitterness you actually experience when tasting beer. The taste profile you actually experience largely comes from the balance between the bitter alpha acids and the sugary malt, so the IBU’s are only one part of the equation.

Compare our Red Ale with our Citrus Mistress, for example. Both beers register 80 on the IBU scale, but the Red Ale is more malt balanced (with caramel malts) than the Citrus Mistress, meaning to most people the Red Ale tastes less bitter than the Citrus Mistress despite identical IBUs.

Two of our IPAs—Alpha Centauri and Alphadelic—illustrate another example. While Alpha Centauri has 100 IBUs to Alphadelic’s 90, most people still describe Alphadelic is the more bitter beer. This is because Alpha Centauri starts with a higher sugar concentration in the wort and more resulting sugars in the final product that help balance out the high amount of alpha acids. The higher ABV of Alpha Centauri also balances some of the perceived bitterness as ethanol itself is perceived as sweet.

The human palate is often said to only be capable of perceiving a maximum of around 110 IBUs (though this is debated) and while some super-high IBU beers have been produced (we’re talking numbers well into the thousands), they’re mostly a novelty. Lagers are generally on the low side while India Pale Ales are known for their higher IBU counts. Our Light Me Up Lager, for instance, comes in lower on the scale at 13 IBUs while Alpha Centauri boasts a hefty 100 IBUs.

Knowing what the IBU numbers actually designate and that different malts, the sweetness of those malts and even the alcohol content can affect the overall taste profile you subjectively experience, you’ll be in great shape to step out of your “comfortable” IBU range the next time you’re sizing up beers at the tap house, grocery store or festival. And you may just discover a new favorite craft in the process.