Strange numbers on my beer bottle

So I’m consuming a tasty bottle of microbrew this evening (from the Two Brothers Brewing Co., if it matters), and my wandering eye alights upon some strange numbers and letters on the beer label:

11.2°PLATO
12 FL OZ
13 IBU
4.5%A/V

The second line is obviously the volume, and the last is the alcohol content. That much is clear. But what do the other two lines mean? I’ve seen these four lines on other beers made by this brewery… but I don’t think I’ve seen them anywhere else. Any thoughts?

IBU is International Bitterness Units, essentially a measure of the amount of bitterness from hops. I’ve never seen it on a beer label before though. Plato is a method of measuring the amount of sugar dissolved in a liquid. This is relevant when you are brewing beer, if you know the amount of dissolved sugar before and after fermentation you know the alcohol content.

Thanks for the speedy reply. You can see another one of their labels here, if you’re interested — the four lines I was talking about are along the left end of the label.

IBU stands for “International Bittering Unit.” Although you can find plenty of references that call it a “bitterness” unit, as Laughing Lagomorph did, I tend to go with Zymurgy magazine as a definitive source there. It’s basically a measure of the amount of alpha acid introduced into the brew with the hops.

As you surmised, the fourth line refers to the alcohol content. The A/V means “alcohol by volume,” which is different from the A/W (alcohol by weight).

FWIW Charlie Papazian in The New Complete Joy of Home Brewing, Gregory J. Noonan in New Brewing Lager Beer and Michael Jackson (the internationally famous beer expert, not the washed up child molesting former pop star) all agree with me. In addition “International Bitterness Units” brings up some 1,130 hits on Google vs. about 660 for “International Bittering Units”.

Plus it seems to me that if you are going to go that route it should be “International Embittering Units”, or something like that.

Ouch. You out-cited me there, Lagomorph. I must have lost some memory cells somewhere. I’m not going to dispute Charlie Papazian–or the other two.

The Google hit value doesn’t do much for me, though. There’s plenty of bad English and confusion on the Web. A few expert cites mean a lot more than a heavily disputed general impression.