Is anyone a member of this site and able to read this article. It seems like they collected data on sulfate levels and hops additions:
http://www.mbaa.com/publications/tq/tqPastIssues/2010/Abstracts/TQ-47-2-0623-01.htm
"We were able to show that process variables in terms of time and manner of hop addition had statistically significant effects on the perception of bitterness, hop aroma, hop flavor, citrus character, fruit character, grassy character, and malt. We also found a statistically significant negative correlation between the intensity of hop flavor and level of sulfate in the brewing water."
http://www.mbaa.com/publications/tq/tqPastIssues/2010/Abstracts/TQ-47-2-0623-01.htm
"We were able to show that process variables in terms of time and manner of hop addition had statistically significant effects on the perception of bitterness, hop aroma, hop flavor, citrus character, fruit character, grassy character, and malt. We also found a statistically significant negative correlation between the intensity of hop flavor and level of sulfate in the brewing water."