The assays we talked about earlier are the main ones, but there might be others. Don't expect to be able to test IBUs unless you spend a few hundred dollars on reagents - iso-octane, octanol, and HCl come to mind. The nice thing is once you have those reagents you'll be able to run a LOT of samples, it doesn't take much per sample. But it's a pretty big initial outlay. Plus you need a quartz cuvette, a plastic one isn't going to hack it with those solvents in there.