Food - Drink
What Exactly Is
The IBU Scale
For Beer?
Though it seems like an enigmatic endeavor, many analysts have attempted to measure the flavor of food and drinks in quantitative terms. These attempts include the IBU (International Bitterness Units) scale, a system of measurement that quantifies the bitterness of any given beer.
A beer can range from zero to 120 IBU, which is the threshold of bitterness that the human palate can detect. The IBU scale measures the concentration of alpha acids, which come from hops in the beer brewing process; these acids then isomerize into bitter-tasting compounds called isohumulones.
Breweries use IBU to indicate how bitter their beers are, but the scale isn't always accurate. Experiments at Colorado breweries showed that beers made through craft brewing, in which hops are added at later stages instead of the beginning, register on the IBU scale as way more bitter than they actually taste.