I’m a new owner of the Ikawa at home and excited to explore this new hobby of coffee roasting. I’m working through the Burundi bag right now and like many of you, I’ve noticed this grassy taste using the original profile. Being a total newbie, I just thought I would get used to it. This is how this coffee is supposed to taste! But I then decided I really didn’t like it.
In Rao’s book, he suggested that for grassy flavors you should “moderately steepen the early roast curve.” So that’s what I did this morning, and the lo and behold the smell/taste of grass/vegetable is gone! (I couldn’t wait to drink the roast).
I’ve also gone overboard and placed thermocouples into the Ikawa and I’m using the Roastmaster app to track the bean and exhaust temperatures using the supported ThermoQ Bluetooth device. This setup is pretty cool (imo). Anyway, here’s a comparison of the Ikawa Original profile (dashed lines) and the modified profile. The -only- change I made to the Ikawa profile was the first Inlet temperature point from 212Celsius@44s to 275celsius@1:00 (kind of like the temperature spike in the Ikawa espresso profiles)
I actually wonder whether 275C is too high…next time I might dial it back to 250C and see if the grassiness comes back. This is really interesting to me — one change totally changed the taste of the coffee! Everything else in the roast is the same (for those looking at the ending of the graphs, both sessions ended at 6:01m. I just forgot to “end” the roast tracking in the roastmaster app so it continued tracking the temperature probes.)