I did some of the new Deterra espresso blend from Hasbean, and it roasts really evenly. I did have real trouble hearing first crack, although you could see the inner chaff coming out. I got to around 430F measured bean temp, and was expecting 2nd crack to start when the temp stopped rising for about 45 seconds, strange thought I, then I realised, I hadn't dialled in extra time on the timer, and it was trying to cool, DOH
. I dialled in some more time and the temp started rising, still slowly, but the Imex does seem to struggle a bit at higher temps.
2nd crack should have been happening looking at the temp, but I couldn't hear it. I stuck my ear right up close, and could just faintly hear a few crackles. The bean surface was looking smooth, but no oil so I hit the cooling.
The resultant roast is very even, perhaps a little darker than I intended, but the surface is almost shiny smooth, looks about to give some oil, but after 12 hours in a bag there was none showing.
I think I will have to learn to roast a little differently than with the popper. With the popper the cracks were easy to hear, but with the Imex, it is very hard, so I need to rely on the temperature and sight more, but I'll get there.
One thought I do have is to put another controller on the motor, so I can:
a) Run the fan slower for smaller bean loads
b) Slow the fan slightly near the end of the roast to lower the noise level, and allow the chamber temp ti rise a bit more quickly.
