My homemade smoker is basically a huge steel cabinet that I set a turkey fryer in. I put a cast iron skillet over the burner and set a coffee can in the skillet to burn wood chunks or chips. The flame I get is orange and comes up clear around the skillet, and the skillet gets black stuff all over the bottom, which I would describe as soot. I have to scrape it off after every smoke. Is this creosote? My food tastes OK, but I wouldn't say it had a smoke flavor. Also, shouldn't the flame be blue? It has an adjustment damper on the burner, but it doesn't seem to make a difference in the flame. I thought maybe it wasn't getting enough air, but the flame is the same even with the door open. Any advice?