« on: September 18, 2015, 01:26:23 PM »
I think open kettle and vigorous boil are the key elements here.
This is the crucial variable (and I skimmed the thread, so apologies if someone already mentioned it). Even the short boil reaches ~8% evaporation volume, which is generally quoted as the minimum for DMS reduction.
This might be one of the reasons I've never had DMS problems even though I mostly cover my brewpot. I typically evaporate 3/4 to 1 gallon of volume with a 60 minute boil, which is 12-15%. (starting volume 6.25-6.5 ending volume 5.5 gallons.)