IBU stands for International Bitterness Units, which is a scale used to measure the level of bitterness in beer. Specifically, IBUs measure the parts per million of isohumulone from hops in a beer, which gives beer bitterness. The IBU scale can range from 0 to 120+, but at this point, the human tongue can’t taste any more bitterness. The higher the IBUs are in a given beer, the more bitter it will taste when you take a sip. However, IBU isnt the only indicator of how a beer may taste, as malt/grain character and sweetness can balance out bitterness in a beer. The IBU scale was invented because it felt important to measure how bitter a beer was, and the assignment of numbers helps with conceptual understanding.

The IBU scale can be used as a general guideline to gauge a beer’s potential hoppiness or bitterness. However, IBUs alone aren’t the full story, as malts and other ingredients added to give a beer its flavors can mask or augment the bitterness you may actually detect upon drinking it. Therefore, the IBU system seems completely arbitrary for the most part.

Here are some common beer styles and their associated IBUs:

• Light Lager — 4-10
• Blond Ale — 14-25
• Saison — 20-38
• Pilsner — 25-45
• Dry Stout — 30-35
• Pale Ale — 30-50
• IPA — 40-70
• Double IPA — 60-120+

In summary, IBU is a scale used to measure the level of bitterness in beer, specifically the parts per million of isohumulone from hops in a beer. The higher the IBUs are in a given beer, the more bitter it will taste when you take a sip. However, IBUs alone aren’t the full story, as malts and other ingredients added to give a beer its flavors can mask or augment the bitterness you may actually detect upon drinking it.