I use an aluminum kettle from Academy Sports. I place it in a galvanized garbage can and add enough water and ice to go up to the handles. I leave the lid on the kettle...sometimes I leave ice sitting on the lid. I add ice as necessary to replace what melts. I sometimes stir the ice around a bit, but I absolutely never disturb the kettle because I really like the cold break that I get when I don't stir the kettle at all--all the solid material forms clumps that are easy to avoid when siphoning. I don't even use a thermometer anymore, because I know from experience that the wort will be down to 20-23C in about 25 minutes, so I pull it out then and when I siphon it, I can tell it's cool enough because it feels cool through the siphon hose, and the stick-on thermometer of my fermenter says the temperature once the level of the wort gets up that far.
