What Does IBU Mean? Craft Beer Terms Explained

Have you ever heard or seen IBU listed next to a craft beer and wondered what it meant?

Knowing what IBU stands for can be a great way to look at a beer menu and quickly weed out those you may not like based on the bitterness level.

Or perhaps the opposite – you can easily identify the flavor of beer you know you prefer.

Understanding IBU is a terrific indicator for craft beer lovers to understand why they enjoy a particular style or type of beer.

What Does IBU Mean?

The term IBU originates from the acronym for International Bittering Unit.

IBUs are the units used to measure the degree of bitterness in a beer, but not through our taste buds, but the number of alpha acids found in the drink.

Since hops are generally responsible for giving the beer bitterness, it can be said that the IBU measures the bitterness that hops gives beer through the alpha acid chemical compounds released during the wort cooking.

After having been boiled and transformed, these alpha acids give one of their characteristic flavors to the beer.

IBU Scale

This IBU scale can range from 0 IBU to over 100.

While it is possible to have an IBU well over 100, most brewers agree 100 is about the top level of bitterness a human can taste. Over 100 and the differences may be imperceptable to the tongue and therefore meaningless.

As a general rule of thumb, you can expect:

  • Under 20 IBUs: typically a light lager or wheat beer style beer
  • 20-40 IBUs: pilsners, porters and the like
  • Over 50: an IPA style beer

The fun begins as a craft beer lover when you begin to experiment with knowing where in the range your favorite beers fall.

For example, as a witbier lover, I know I tend to like beers with an IBU of 37 of under. But the only way I discovered that is by tasting many types and learning my own preferences.

And it’s important to understand there are always exceptions to every rule. There are beers under 37 I don’t like one ones over I do.

Knowing IBUs can be a great tool for narrowing down what to order on a beer menu, but won’t guarantee you like it.

The Exception Of The IBU Indicator

I love the analogy of a cup of coffee many brewers use as a refernce.

Have you ever had a bitter cup of coffee? As soon as you add cream or sugar, the coffee tastes less bitter.

The component of bitterness still exists in the cup of coffe, but we’ve just masked it with other flavors.

The same applies to beer. There may be cases where a beer registers with high IBUs, but the flavors are balanced reducing the bitter taste.

Or perhaps it isn’t the bitterness you don’t like, but the taste of a specific type of hops (generally the most bitter ingredient). For example, you may not enjoy the piney flavor of Columbus hops, but you are okay with others.

As you dive deeper into the world of craft beer, you will begin to understand what you do and do not like.

How Is Beer Bitterness Measured?

The most bitter ingredient in beer is hops; therefore, it is the essential ingredient in calculating the IBU.

We must also understand that not all hops add bitterness. This is because the bitterness is provided by the alpha acids contained in the hop plant, and there are hops with a little amount of these acids.

During boiling, the release of these alpha acids occurs; therefore, the hops added in this phase will give bitterness, while if they are added at the end of the boil or after dry, it will provide aroma and flavor but not bitterness, since beta acids will act in this phase.

Depending on the alpha acids in the hops used, the beer will have more or less bitterness. This characteristic bitterness in beer is measured with the IBU indicator.

Therefore, the higher the IBU indicator of beer, the greater its bitter taste.

How Does This Indicator Work?

The higher the beer’s bitterness, the IBU indicator will grow, having a direct relationship between both properties.

To get the IBU indicator for beer, you have to perform a complex procedure of scientific formulas and equations and use specific equipment to study it.

These equations take into account data such as the type of hops used in cooking, cooking time, time of incorporation of hops, in the beginning, or the end of the beer preparation process … All this to find the IBU indicator of beer.

The result of these accounts is as follows: for one milligram of alpha-acids, it is an IBU.

To finish this process, the IBU indicator must be divided between the original density minus the final density; if the value is close to 0, this beer will be malt and smooth. If it approaches 1, it will be a bitter and robust beer.

Currently, many brands already indicate on their label how many IBUs they have so that the consumer himself knows if he is dealing with a more or less bitter beer.

The Spectrophotometer: Device To Measure The IBU Of Beer

An IBU is not easy to measure if you don’t have the necessary equipment, such as the spectrophotometer, a fundamental tool in a laboratory that also helps to study the color of beer.

This helps to obtain the correlation of the bitterness found in the beer, with a value resulting from the concentration of bitter compounds in it.


Understanding International Bittering Units (IBUs) is a key lesson along your craft beer journey. While it can be a terrific guideline for knowing your personal preferences, don’t let a beer’s IBU keep you from sampling it if you are curious about a particular beer, as the flavors may be well balanced.

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