effect of sulfate does improve the perception of bittering. I'm guessing that adding an extra 150 ppm of sulfate can add somewhere around 5 IBU's of bittering perception. So for those of you thinking about trying higher sulfate on a beer recipe that you've fine tuned the bittering to perfection, you will likely need to back off the bittering a teeny bit to have a similar balance.
Interesting observation Martin. I will keep that in mind next go round with high sulfate addition brews.
+1. Makes sense. Thanks for posting, Martin.