Context: I have done hundreds of roasts on a Gene Cafe and have recently switched to a v1.5 bullet. Trying to figure it out and struggling. I’m about 50 roasts into and for my preferred batch size I feel as though I have a semi smooth declining ROR. The coffee though is tasting rather flat and lacking flavor. I also am slightly clueless on final drop temp or development time. I have read loads from Hoos and Rao and home barista forums, but no one seems to give a good range of an area to start. So it’s entirely possible my dev times are too short or my drop temp is too low. I am aiming for a light roast highlighting origin flavors and acidity. This roast is for a dense Ethiopian Guji G2 bean.
Have you tried using less fan speed? I’ve seen too much fan produce flat flavors (but beautiful curves). You would need to control RoR with power changes, which can take 30 seconds or so to show an effect in the curves. So you have to anticipate and apply changes in advance, which takes some experimentation. Try limiting fan to F2 or F3, perhaps up to F4 post-FC for a natural process bean. Hope this helps! - Brad
Would you recommend continuing my low temp soak method or should I abandon that? Trying to figure out if the timing of everything is good and I just need to lower fan speed and lower power or if I should try to speed up the roast since lowing the fan speed will naturally do that.
Your overall profile, preheat, weight loss, development time, all look reasonable, at least for a starting point for a new bean. I guess the coffee isn’t terrible, just a little plain tasting? That’s what I found from using too much fan. So less fan is probably worth a try. If you do, please let us know what you think.
I also like to use lower power for the first minute, because I think there is a potential for early scorching. I check for early scorching using the tryer once in a while, especially for the first roast of a new bean. Rob Hoos has an interesting Roasting Defects video that discusses this. But I honestly haven’t seen it more than once or twice. Maybe others will add their experience.
Sounds almost like baked coffee? I think 10 minutes could be a bit long for a medium roast (that’s not a full 1 kg batch). Less fan should get you there.
Maybe even smaller batches while you figure it out? Do Ethiopian coffees from other roasters taste good to you?
(And perhaps add Morten Munchow to your reading list.)
I am wondering if it is baked as well. Typically Ethiopians are my absolute favorite. I love wild and experimental coffees. My struggle is dialing in this particular roaster. I know the beans are great, I have roasted and sold loads of bags from this particular lot of Ethiopian Guji beans and I regularly make excellent pour overs and espressos with it. But dialing in the roast on this new roaster has been quite the challenge. And the tough part is with a Gene cafe there is no real data to go on. I just happened to find a temp and time on that machine that worked well for this bean and I’m new to this journey of building and developing a roast profile.
FWIW, this recent one for me for an Ethiopian natural turned out quite well for me. It might be a bit darker than you want (in which case I’d drop the beans sooner). It’s about a 1lb batch with a drop temp of 430F on the IBTS. I use a bit of heat soak at the beginning and like Brad I stayed with F2 and F3 for most of my roast until towards the end to get the chaff out and not let the roast run into SC. Also… I don’t get too hung up on a smooth RoR
EDIT: I came from a FreshRoast which also had no data and completely different from the Gene. It took me a lot of roasting and learning from Brad to get to where I’m finally comfortable with what I’m doing at the 1lb and 1kg batches (2 yrs and 120 odd roasts later).
I have redone a few coffees and tasted them. They have definitely improved however they are still lacking. I will include some roast profiles of a Washed Honduras La Navi and a natural Ethiopian Guji blend. Any critiques or advice you could give would be super helpful. The Ethiopian is good but slightly lacking overall flavor, and the Honduras is hollow and drying on the tongue.
