This is what they should really call them because since breweries started advertising IBU’s (International Bitterness Units for those that aren’t already obsessed), they have really been a d**k measuring stick.
“Hey look at me and how many IBU’s I can put in my beer.”
“look at how many IBU’s I can drink.”
The problem is that consumers have grabbed on to them as actual tasting information when they are, in fact, a purely scientific measurement. Using them to describe how a beer will taste is like, as Ross put it, “trying to describe how a person looks but only talking about their weight”. A 170 lb person looks totally different if they are 5 ft tall or 6 ft tall. So I have decided to give a lesson on IBU’s, how they are created, how they affect flavor, and why we shouldn’t talk about them.
What is an IBU?
An IBU is a measurement of isomerized alpha acids. Iso-alpha acids are what give us the bitter flavors in beer and come from the hops added during the boil. An IBU is equal to 1 ppm or 1 mg of Iso-alpha acids per liter of beer.
Why they matter or do not matter?
They matter to us as brewers because it is a measurement that we like to keep consistent, so every batch has the same perceived bitterness. Why they shouldn’t matter to you is because they have no bearing in perceived bitterness between different beer styles. Take this example: I can make a big double IPA and put 85 IBU’s in it and it won’t taste more bitter than a 5% ABV IPA with 45 IBU’s.
Whawhaaaat? The perceived bitterness is affected by the residual sugars among a few other things.
The D**K Stick
Have you tried a 120 IBU beer? No matter what your answer to that question is, it is actually “probably not”.
I’ll explain why. To get isomerized alpha acids you have to start with alpha acids that come from hops. These hops get thrown into kettle of boiling wort to get isomerized but it’s not that simple. The alpha acid have to first go into solution before they can be isomerized which is hard because the saturation point in wort is very low and the alpha acids are sticking to everything (sides of the kettle, etc).
Let me paint a picture.
The Alpha acids are people waiting to get hammered at dance club that is inside a Geo Metro. There is a line outside and only 1 drunk person is leaving every 5 minutes. At the same time there is a gang of demented giraffes eating the people in line.
Unless a brewer is using pre-isomerized kettle extract or a post fermentation bitterness product, it is actually very difficult to get much more than 80 IBU’s into beer. Unless it is measured with a spectrophotometer, don’t believe the claim.
So what is the lesson in this disjointed acid trip of a blog? Leave the IBU’s to the brewers.
Taste the beer, if you like it, drink more of it.
If you don’t like it, don’t drink it. It’s that simple.