Since attending Joe's roasting course at Cafe Imports (http://www.mplscoffeemill.com/
), I have been playing with a bit more airflow.
Roasting on the North TJ-067 (natural gas). Plenty of umpf available with this fan arrangement. I have eased a bit more air into the stages with some success and some failure. I got one very nice roast. But when I tried to introduce more air into successive roasts, I lost convection heat in the midst of first crack. It will take more time, patience, and experience.
Joe suggests that a bit more air than I had been using will help with the sweetness of the coffee. I believe the fan's capacity might well be greater on this roaster than others (minimal experience on Diedrich, Probat, and USRC). Looking forward to Joe's/Tony's discussion and Mark's Nov Roast and Learn. Lots to learn!
Previously used these settings on the TJ-067 under a 1K charge:
90 sec: min air, 18% setting, just enough to keep fan spinning
90-1st crack: 35% setting
1st crack to end of roast: 40% setting
Successful improved roast:
90 sec: min air 18%
90 sec-1st crack 45%
1st crack - end of roast 60%
Still experimenting. Not finished playing.