I'm looking for some feedback on using a Corny Keg as a secondary fermenter. Is it necessary to rig up an airlock or can I simply seal the keg and allow the appropriate time for aging? I'm concerned about fermentation gasses (those other than CO2) not being properly vented. I've only tried this method once with a lager yeast that was producing some sulfur smell. I primary fermented for 2 weeks then transferred to a Corny. End result was a beer that had a hint of sulfur in the aftertaste. Any feedback would be appreciated.