Hi Coffeesnobs,
I have only done a dozen or so roasts with the Hottop KN-8818B-2K. Previously I had only roasted in a popper so I'm new to profiles.
The Hottop just about makes you use a 75C charge temperature. After multiple undrinkable roasts using 75C charge temperature (including Auto mode which produced such disgusting coffee that I only used it once) I changed to 125C then 140C charge temperatures and the results were pretty good. I used similar heat and fan settings through the roast and aimed at a temperature rise of around 5 seconds per degree C.
I've read that the heating before yellow doesn't have any effect on the finished results, so it's hard to see why the different charge temperature made so much difference.
I wonder what others have experienced with this roaster, and what charge temperatures you use?