I only skimmed the experimental description yesterday, and I have yet to listen to the podcast, but I did note that to make the experiment easier, they dosed glasses of beer rather than brew multiple batches with different sulfate ratios. I have a rather large blind spot for biochemistry; is this a fair way to do the experiment? Is the perceived "hoppiness" only dependent upon the sulfate/chloride ratio after the fact, like adding salt to a cooked meal, or does the ratio come into play during chemical reactions going on in the kettle or fermentor?