Wow, I'm suddenly digging this site. A lot. I've been a lurking member for a quite a while to help with my espresso learning curve but somehow I didn't know there was a whole home roasting aspect to HB until I found out about the roasting competition.

Edwin,

I've been roasting with a Gene Café for 2 ½ years and may be able to help a bit. First, your observations about the clues from the beans are right on! No matter what temperature the roaster tells us, we know the beans turn yellow at about 330F and are about 400F at first crack; you hit this one right on the head.

Now then, the Gene Café. Keep in mind it's not a typical air roaster, but rather more of a hybrid air and drum roaster. As I understand most air roasters (please correct me here, if need be - my air roaster experience is limited to the Fresh Roast beans are heated and lofted by rapidly moving hot air. Aside from momentary contact with the sides and bottom of the roasting chamber, I believe they spend most of the time airborne. The hot air in the Gene Café does not move at nearly the same velocity. The drum, rotating off-axis to the center of the drum not only contains the beans, but also heats them by convection air movement and conductive heat transfer. Meaning the beans are never airborne, but constantly in contact with the outside of the drum and the metal divider plate as well as each other due to the slow rotation of the drum.

I'm a believer in preheating the drum, particularly for more dense (SHG, SHB) beans. I usually preheat to 300F, and by the time I get the beans in and the drum re-loaded, I may lose 25-30F. My set temperature varies depending on bean again, but it's usually somewhere between 460- 475F. Then, depending on the bean, I'll hit 1st crack about 11:00-12:00. At the onset of first, I drop to 445-455F, flattening out the profile, and I may hit 2nd crack within 5 minutes of the onset of 1st. , if I roast that far.

Lately I end the roast by always going to my external vacuum/colander cooler. Using the roaster's cooling cycle at the onset of 2nd sounds intriguing. I think I will give it a try this weekend. Is my coffee any good? I dunno, but my friends and family like it a lot and Jim and Thompson will be giving me their opinions pretty soon

Given what I've read here, I think I'll try a few new things this weekend.

As to heat profiling, the Gene Café temperatures climb at the same rate, no matter what the high setting is. However, if you want to, say, warm the beans at 300F, the roaster will cycle on and off maintaining a temperature near 300F. I say near, because the heater will cycle off at 300F, drop to 294-295F and cycle on, back up to 300F. It will average about 297-298F instead of 300F. I doubt these momentary drops are affecting the beans much, but perhaps they are. Anybody else have thoughts on this? Setting a temp this way can slow your roast down very nicely, if there's a need, like after the onset of 1st.

Thanks for the ideas, all, and thanks for letting me into the sandbox.
John