http://scottjanish.com/survivables-unpacking-hot-side-hop-flavor/"... beers were brewed with Simcoe, Citra, and Mosaic in the whirlpool and tested for final concentrations of the various isobutryic esters across multiple yeast strains and found that SafAle S33 and SafAle K97 retained the highest concentrations (US-05 had the lowest levels) of isobutryic esters..."