charcoal. I had this big bag of lump I bought at GFS and it didn't perform very well. I started thinking that I would need to blend my hardwood lump with standard briquettes to control the heat. Last week, I knew I'd be smoking and I was out of that cheap stuff, so I bought a 10# bag of the Kingfsord lump at Drug Mart. It cost twice as much, but I swear it lasted twice as long. Consistent 225-250 for 3 hours and I could still do a tray of ABT's while the meat rested. I'll use nothing but this Kingsford lump in the future. Well behaved charcoal is critical to good smoking, IMHO.