@CarefreeBuzzBuzz, I had dropped gas pre 1C, in earlier roasts with crash, and for those two I avoided it because of comments that Scott Rao had made advising against cutting gas within 45 sec prior to 1C. I can get those .alog files to you,a bit later, or try to add them to my post #11.

Oh and I think I'm getting why Tom say sarsaparilla in my full city roast.

I cut gas and then return to 1.6 to 1.8 x the cut amount. Generally the cut is anywhere from1:45 to 1:15 pre est FC and the ramp back is 60 to 30 sec pre est FC. I know SR says 45. I have had it work as low as 30.

I might increase the airflow if the crash is too much of a problem for you.

The crash is a reading of the intense exothermic reaction happening and overloading the probe. It doesn't mean that the coffee has stopped developing, but that the 1C development is happening more quickly and efficiently than on other coffees. Don't be too phased by the crash, but try to predict where you want to be as soon as the exothermic reaction stops happening. Anticipating for the return point (when the crash will stop and the RoR will jump back up) will greatly help navigate the remaining portion of development you're seeking.

With that said, greater airflow (provided it's heated airflow) will greatly help offset the impact of the exothermic reaction. The greater quantity of hotter air present around the probe/beans will mitigate the intense burst of the exothermic reaction and enable a smoother transition in the RoR. It will also make the bean become endothermic again more quickly and efficiently (leading the way towards second crack).

With that said, great airflow means more intense heat applied to the coffee as well as potential to bake the coffee more quickly. Finding the optimal airflow/heat conditions during this "crash" can only be calibrated by cupping the coffee and finding the ideal conditions for development via triangulation. I don't believe that a predetermined RoR trajectory on a graph is going to provide this necessarily...

I do not profess to know what I am doing, but here is my first roast.
I felt rushed by circumstances last night. I charged too low and ended too soon. Plus a few issues in between.
I just made an AeroPress 20 hrs post roast using a fine grind.
I tasted peaches!!!, which didn't last as the cup cooled. The aftertaste was floral, narcissus.

Hi there,

I'm glad to hear about your take on the Huky because I wanted to have a way to compare my methods with other people using the same machine.

I'm roasting with the perforated drum - that may have a big impact on the different roast properties. The solid drum presumably has more thermal mass than the perforated drum, which means that the charge on a solid drum will heat the coffee bean mass more quickly.

Also,

The heat setting I use really depends on the coffee. For example, a Guatemala Gesha I roasted a few months ago could not take anything above 3.8 KPA and went into FC at 8 mins. This is a particularly dense coffee, and rather uniform for Ethiopian washed, and that's why I'm using such high heat settings.

The kind of probe used also would have a big impact. Mine are super sensitive, and even if I slightly pull out the trier, the probe will register it and screw up my RoR graph significantly. This leads me to talk about the exothermic reaction actually having a discernible impact on the probe reading. There are different takes on the impact of the first crack on the probe readings, but in my particular case, and for this specific bean, I feel strongly that the crash is happening because of the uniform 1C.

Lastly the strength of airflow has a huge impact on the roasting efficiency. More airflow will strip moisture faster and distribute heat more intensely. As you can see from my graphs, the difference in timing of heat and airflow gave me hugely different FC timing/temperature reading (even though the audible first cracks happened in almost identical fashion). The variac used on the Huky can behave differently from unit to unit, and the progression of airflow quantity isn't linear. Another possible contributor to our different roast profiles.

SAS wrote:.
I tasted peaches!!!, which didn't last as the cup cooled. The aftertaste was floral, narcissus.

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I hope you get more of that. One of my City roasts produced an espresso with a nice peach linger, as well. So I hope I get more of that, too.

This bean what's to be chocolate for me, so I'm going to take it to the beginning of second crack. And hopefully be able keep the peaches. For me after trying some roasts the peaches are coming in as a back and after taste and not fully in the forefront which is what I usually aim for the fruits to be. Are you guys getting similar peach flavor?

4 days rest and we finally tried my 1st attempt. We used a Chemex @ 14:1. Great mouthfeel and flavor come on as the cup cools. Peaches, possible. It's not grassy and that's a good thing.

This mornings roast's.