BeerTools Tinseth Implementation

I was wondering if anyone has compared the BeerTools implementation of the Tinseth models for hop utilization with manual runs through his equations on realbeer. It seems that BeerTools comes up with higher numbers, off by as much as roughly +15 IBUs around OG 1.100.

I am writing a boil clock program and am incorporating hop utilization calculation since I usually have to adjust my additions right before I boil due to variation in alphas. My implementation performs the math as described at http://www.realbeer.com/hops/research.html but I was noticing the numbers didn't line up with BeerTools.

Soooo, does BeerTools know something I don't, or just have an incorrectly implemented Tinseth model?

You can check out my timer program, Brewklok, at my site: http://www.fortunebrewery.com/software/brewklok.php

Any input on how the numbers it returns compares to the tools you use is greatly appreciated. Thanks!

You'll need Java 5+ installed to run it. I'm still working on it so there are a few things not quite working yet, but the IBU calculation should work fine. There is a more complete set of instructions on the launch page.