by JimG » Thu Oct 30, 2008 7:03 pm
Hi, Sergey -
I added two temperature sensors to my Hottop B. One measures the environmental temperature above the beans, the other is located within the bean mass.
So my temperature profile is going to look different. But I think there is still some useful information for comparison:
1. During the drying phase, I adjust heater power so that the environmental temperature does not rise above ~180C. You can see on the plot that the slope of the red line flattens out at around the 5 minute mark as a result of turning down the heat to maintain 180C.
2. After the bean mass has reached ~150C (at around 8 minutes for this roast), I turn the power back up to 100%. I watch the environmental temperature again, and when it starts to approach 230C, I gradually dial it back down, maintaining 230C as closely as possible. Again, you can see the slope of the red line flatten out at around 13 min as the power is reduced.
3. I go around 4 minutes from FC to SC. Some roasts require increasing the power again to have the bean temps rise. Other roasts, the bean mass will continue to rise on its own and result in SC occurring at ~4 minutes after FC.
I have found that the most effective roast control seems to be to directly control the environmental temperature. After a little trial and error, I discovered that a ramp/soak profile with ~180C and ~230C "soaks" gives good results. I also try to not ever allow the environmental temperature to drop as I am told this has detrimental effects.
Compared to your profile, I think I might suggest hitting full power again as soon as the beans are yellow, but then tapering it off as FC approaches. I might also suggest that too large a power reduction during FC might allow the environmental temperature to drop, so small adjustments starting in advance of FC are probably preferable.
Jim
- Attachments
-
- 20081019-canario-celsius.jpg (74 KiB) Viewed 9993 times