Ethiopian natural medium roast came out great. How do I turn it into a light roast?

I roasted 333g of it, and have 666g left. The medium roast was great. How would I change my parameters to make it into a light roast?

My “problem” is that I stopped it right at end of first crack. I could not have stopped it any sooner, as the beans had not stopped popping. From first crack to the end, it went from 204 degrees to 212. To achieve a light roast I’d imagine I would have to get all the beans to crack before going much past 208 degrees.

How can I achieve that? I can increase fan speed, but i’ve read this is a bad way forward at low loads, like 333 gram. Should I maybe go to P0 instead of P2 at the end?

1 Like

It is not necessary for all of the beans to finish first crack before dropping.

I do a lot of Natural Ethiopian roasts with 500g of beans and am preheating to 482. For 333g I would reduce the PH to ~450. My first crack usually is going strong at 393 and I drop at 408 for a medium/light roast at around 9 minutes. If I wanted a lighter roast, I would try dropping around 402.

This is what I would do but I am just a novice with the Bullet. (only around 100 roasts so far on the Bullet, lol. I had a lot more than that on my HotTop)

Roasting a light degree one of the key is to identify the accurate FC. Because the total DT is quite short (ex. DT=45 seconds) if we missed the real FC, the total DT became shorter or longer thus impacting the roast degree and the final taste significantly. With Ethiopian natural/washed beans it needs a lot more experienced “ears” due to its various beans size , grade (G1~G5),…and many other parameters of a particular batch of bean. The FC sound tend to start slow and muted with long silent interval between pops…i would strongly suggest to use an external Mic/Amp which will help clearly “hear” when/how many pops thus to help making accurate decision of the FC.
To my experience, I am in line with BillC’s data that the FC of a Ethiopian natural is around IBTS 200c~201c depends of the batch size. In this case, your roasting of FC should have already reached at 7:21 instead of 8:05…this is total of 44 seconds long and can have a huge impact of a light roast.
Here is my 2 cents suggestion for a light roast
If keep the same profile as of now
2. Use 200c as the FC point to count your DT
3. Drop the beans 1 minute after FC…most of the time, this will give me an Agtron reading of 90+/- 2
If modify the profile is an option

  1. Adjust power down to P1 after 200c reached (or FC reached assuming you have found a way to better “hear” the beans activity)
  2. The purpose to drop to P1 is the drive the RoR within 5c+/-2 after FC.
  3. Dump the beans after 50 to 60 seconds will give an Agtron around 95+/-5.
    Again, this is a rough idea according to my limited experience. Hope that helps.

Thank you both. I will try to drop them sooner. I was just worried I’d get too many grassy beans. But if that happens I can always try to modify profile in a 3rd attempt.

And yes it was very hard to hear first crack. If you define first crack at “first couple of pops closely together” it could definitely have been happening already at 200 deg, I just marked it later when it was unmistakeable.