IBU for Dummies

After posting yesterday, I set off to the kitchen to make this year's IPA.

(I am still debating whether or not to post recipes here. Part of me wants to throw them out there, open-source style. Another part of me entertains the fantasy of opening a brewery one day.)

Anyway, I set out to make my IPA, and being the (ahem) highly trained scientist that I am, I wanted to aim for a particular level of bitterness: slightly higher than most commercially available IPAs, but not ruin-your-pallete-for-the-rest-of-the-night bitter, either, a la Stone's excellent Ruination IPA.

As it turns out, this means exactly somewhere in the region of 60-70 international bitterness units (IBU).

Calculating IBU is tricky, because in addition to knowing the alpha acid content of your hops, you need to have some idea of the percent utilization, which is a function of both the specific gravity of the boil and the amount of time each hop addition spends in the boil.

Two things made this a lot easier. The first was the wine thief I bought that makes sampling the wort for a quick hydrometer reading quite easy (I took my sample just as everything was dissolved, but before it started boiling) and the second was this handy online calculator that enables you to input the relevent data and spits out your IBU estimate. I ran to the computer and had what I needed before the pot started rolling. Pretty cool.

We'll see how it turns out in about 4 weeks...