This is the first in what I hope will become as all things are with this blog an irregular series on Beer Education.
First, up “What Does That Number Mean?”
If you ever looked closely at a beer label you might see a few Abbreviations and numbers. The question is what do all these abbreviations and numbers actually mean. Today I am going to focus on the two main numbers: ABV and IBU.
First up the one I am sure everyone is familiar with ABV – Alcohol By Volume. This is a measurement of the amount of ethanol or alcohol in that beverage compared to the entire volume of the drink. This is measured by using a Hydrometer and taking two measurements during the brewing process and using a basic formula to get a final ABV. First after the wort is boiled and cooled before the yeast is pitched into the beer for the fermentation process a measurement is taken with the Hydrometer. This reading is known as the Original Gravity (OG) of the beer (FYI: Water should have a reading of 1.000). Then once the fermentation process is done another measurement is taken using the Hydrometer called the Final Gravity (FG) of the beer. Then to get the final ABV the following formula is used:
(OG – FG) * 131 = ABV
Obviously, we all know that the higher the ABV the less a person needs to consume to become drunk, but also the higher the ABV usually the more “alcoholic” the beer will taste.
Next up let’s discuss IBU or International Bittering Units. This is a measurement that let’s you know the amount of Alpha Acids left behind from the Hops during the brewing process. Below is a chart of basic beer styles and their average IBUs.
Now this number is not a 100% direct influence as to how bitter a beer may be as it gets balanced out by the malts that are used. However, generally the higher the IBU the more bitter or hoppy the beer will taste. IBU’s are not something that a homebrewer can easily test on their own as its a highly complex test, so if you are trying to find out the IBU of a beer, you may want to seek out a lab that you can send a sample to for testing.
There you have it next time you are out drinking with your buddies and see ABV and IBU on the beer label or menu feel free to speak with a little more bravo and knowledge to impress your friends.
And that’s … From My Mellin!