Gesha Roast Level

Hi All, i got a chance to roast 1lb of a natural Panama Gesha. The beans itself were large. Probably a 17 or 18+ screen.

The plan was to roast light. I wanted to go about 1:15 past calling first crack, which is what I did. I even felt that I called first crack early. When i dumped the beans, first crack was still audible - perhaps towards the end.

To my surprise, got a mass loss of 13.5%. I was predicting closer to 12. Wanted to get some thoughts on the relatively high % loss given the roast parameters. Also wondering if the higher humidity at this time of the year is contributing to higher moisture and weight of greens.

Waiting a few days before brewing!

Well, I had a few incidents with the dead man alarm while roasting my Peruvian gesha, but if you want to decrease your loss, you should aim at around 4.5°C delta temp. As you can see from my roast, I was on 13% development vs your 12%, but got 11.9% loss, while you got 13.5%.

My other roast is also in that range, as regards delta temp, but the cooling wouldn’t start because I stopped the roast via PC, while the alarm went off. I had to cycle through all the steps to get the cooling to start. Thats why it says that delta temp was 10°C, but it wasn’t. Also why I had 13.1% loss instead of 11.9%. Delta will be the result of everything you’re doing through the roast. It wouldn’t be advisable to drop a lot during development, but control the temperature during the roast so you have a lesser delta in the end. With a delta of 10°C, your roast would’ve lost much more with the same 12% development, because it would’ve been hotter throughout. I’m not yet 100% satisfied with mine and plan to lower the PH even more next time. Although it’s a high elevation bean, it seems to be roasting pretty quickly with my current settings. It is spectacular in the cup, but I want more. BTW, if you look at my first 500g gesha roast, there I didn’t click on “Yes” when it asked me if I wanted to stop the roast. So even there the delta was around 4.5 and development around 13, instead of 4.9 and 15 that’s being displayed.

P. S. II don’t think humidity has an effect if you’re storing your beans properly. Improper storage would create far greater problems, especially with increased humidity.

Gotcha. That makes sense. Thanks for the tip. A little bummed that I did not come across this with other beans I’ve roasted. If you had a chance to redo roast (I don’t since I only got 1 lb of it), what would you do differently? (Or a combination of items…)

  • Reduce momentum going into 1st crack?
  • increasing fan post 1st crack?
  • decrease power post 1st crack?
  • something else?

In my case, the next roast would be 270°C PH and start with P8. That would eliminate one unnecessary adjustment and get it to slow down sufficiently to have FC a bit later. For the 500g one, I’ll just probably lower the PH to 220°C and keep the rest. I rarely touch the power button post FC, just the fan. So, I guess the first two, although the first one is much more important. Anything involving less PH or lower power settings in the beginning, or the combination of the two, should hypothetically get you there. But it is really difficult, if not impossible, to roast a coffee once and get great results. Of course, with enough luck, everything is possible.


I just started doing this with my Ethiopian roasts to ensure they don’t get too roasts/smoky.

Took the two power drop Munchow approach and replaced the second power drop with a fan bump. So for a 455g roast, P6 to P5 just before FC, with F3-F4 during Maillard, and F4-F5 to tamp down the flick.

Really liking the cup results with this so far.


I’ve done some testing today with my gesha, and I have to correct myself. Anyone reading, please bear in mind that this is my takeaway from my particular beans and roasts. I don’t really think the preheat matters all that much. I have come to the conclusion that no matter how hot you start, without exaggerating, you must enter first crack as gently as possible with high fan setting. These beans seem to run through maillard very quickly and you must slow down immediately after yellowing and once more before FC. So, I guess I was right about the fan, wrong about the importance of PH.


Yes. Thanks for the follow up. What Gesha beans were you roasting?

Both of mine were from Sweet Marias. The Guatemalan did not act much differently from my experience with Ethiopians. The Panama gesha was different both in roast ing and its appearance (very large seeds)

You can see all my roasts on RW. I’m roasting a Peruvian anaerobic/honey. From what you’re describing it seems we have almost the same bean. Mine are also very large and the roasting is also different from other beans that I have. The closest, in terms of roasting style, is the Cuban, at least for me. You know, I heard Lamastus say in an interview that he couldn’t tell the difference between a Panamian and Peruvian and some other geshas grown properly in higher elevations. He’s certain he’d fail the blind test.

You mention Mallard here, but nothing about Delta, has your roast approached changed in the last 3months, or are you just emphasizing different aspects situationally? And if so, when do you refer to one over the other?


How do you approach Guatemala/Ethiopia differently from Panama/Peru lately?

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