Trying to get a light roast (help)

Hi, I’m new to roasting but not to coffee, I run a coffee shop and taste many amazing coffees every day and have taken the next step in trying to roast some myself. I have followed the suggested light roast specs from Aillio. I’m trying to roast 2 Ethiopian naturals for pour over, I have roasted a Bensa and Gora from falcon-micro and after cupping them they seemed fairly decent ( was expecting first roast to be horrible ) fairly sweet / fruity smell and tasted okay but in my experience with these beans I feel they are lacking. after a fairly exciting cupping I tried to brew them but the coffee was way nicer in the cup.
should I leave them rest longer before deciding to make some changes? its only been 24 hours.

any suggestions or clear mistakes I have made would really help on the next run.



Hey @ansomeuko3cf - welcome to the roasting journey! I’m fairly new myself, but in my limited experience, light roasts (especially Ethiopian heirloom) benefit from longer resting times. I’ve had some that peaked in flavor after 7 days. I’d sample it over the next week before drawing too many conclusions. Your profiles look good!

Those look like very reasonable roasts, great first attempts. I agree give them rest, especially light roasts benefit from a week or more.

A couple of ideas to try:

You’re getting pretty high weight loss for a light roast. Try speeding up a bit, see if you can get weight loss down into the high 12% range. I like to start with 1 minute at P7, then increase to P8 for a minute or two before decreasing back down to around P4 at first crack. Hopefully the Ethiopians can take the heat without scorching.

Try using less fan, just enough to clear most but not all of the chaff. Depending on the bean you might be able to get by starting at F2 and increasing to F3 around first crack. Manage the RoR with power changes instead of fan, being mindful of the ~30 second lag before the power change influences the RoR.

Hope this is helpful! - Brad


I’ve come to the same conclusion, Ethiopian Nats are a pain and need some rest. After 7 days min they bloom otherwise they tend to be underwhelming. Odd but it’s the what I’ve experienced.

I would recommend trying to smooth out the hump in the ROR between the 6-8 minute mark it could be an indication of uneven development.
I’d suggest:
Keeping it at P7 for longer (maybe 2-2.30mins)
Up the fan to F4 earlier(maybe at 6min)
Cut heat more aggressively once you know you’re nearing the hump, but not too much that you stall the roast.

Ethiopians generally have the tendency to go quite exothermic before first crack so I’d usually try to anticipate that and drop heat early enough before it happens.

I would drop power to P4 @IBTS 180C , adjust again to P3 @IBTS 190C, then use P1 when FC. for about 1 minute to drop the beans. Keep the Bean RoR <10C near FC point is what I like to roast for an Ethiopia light roast