What does ibu mean on a beer bottle

But what does IBU mean? A few of your beer-loving friends might tell you that number is a gauge for how bitter a beer is. Before I give you that definition, know that alpha acid comes from hops, and they are isomerized rearranged chemically when boiled. An IBU is a chemical measurement of isomerized alpha acid in parts per million.

In theory, a higher number of IBUs means more bitterness. A few months ago, I had a man come into the Red Rock Beer Store demanding to know how many IBUs were in the helles lager we had available for growler fills. About the Author: Anthony Towey. Anthony Towey spent over a decade working nearly every position in the bar and restaurant business before being hired as Content Editor and Social Media Manager for StateVentures- publisher of ShoreCraftBeer.

His combination of writing expertise, marketing savvy, and service industry experience puts him in a unique position to be able to help the local breweries like few else can.

One Comment. William Marytn December 18, at am - Reply. Each compound will have a unique spectra, giving it a fingerprint that can be used to identify quantities of that compound, such as this one for ethanol.

The main instrument used for this type of measurement is called an alcolyzer and will give you alcohol and density measurements. IBUs are an attempt to quantify the relative bitterness of beer. I say an attempt because it is specifically the measurement of certain compounds iso-alpha acids and taste perception is rarely the result of any one compound in isolation.

However, it is still an important measurement that will give the consumer a relative idea of what they are getting into. So, a little more on alpha and iso-alpha acids. Alpha acids are a class of compounds there are 3 major ones found in hops that, when introduced to the boil convert, or iso merize, into the iso-alpha acids IAA. These IAAs are very bitter and are responsible for most of the bitterness of beer. Again, there are many ways to measure IBUs, but two are more common.

First is by extracting the IAA by use of an acidified organic solvent iso-octane and then measuring the absorbance of the solvent at nm spectroscopy again! This is optimized for IAA extraction, but other compounds will also be extracted and will exhibit absorption at this wavelength, so it is more of a general measurement than a targeted measurement.

This is the current and most used method, as it is relatively cheap and accessible. The amounts of those relatively pure compounds can then be measured with some sort of detector. These instruments are very precise and highly useful but cost much more money than the spectrophotometer needed for iso-octane extraction, and generally require dedicated training to run.

Alright, I think I have thoroughly nerded out enough for one article, but I hope you have a better understanding of some of the numbers you might see on your next beer bottle or can. And while these numbers are important, they are by no means the only things we measure or monitor over the course of making each beer.

Without a high performing quality team monitoring proceedings, things can quickly go awry. Here at Lagunitas, our quality team is performing well over tests on each batch of beer to make sure there are no surprises! Beer What's on the label? Read story.