http://www.guardian.co.uk/lifeandstyle/ ... ppest-hops" onclick="window.open(this.href);return false;
"Over the last 30 years or so, American agricultural universities and hop farms developed a multitude of new hop strains, like Amarillo, Cascade and Citra, most of which have bold aggressive bitterness and huge, fresh, largely tropical flavours. Those hops inspired a pale ale revolution which elevated US beers beyond the unremarkable brown session beers which had previously, and to a certain extent still, dominate English cask beer production."