I've been roasting a lot of coffee over the last few weeks trying to understand the process and what I can improve as much as my Behmor lets me. I understand I'm quite limited on it right now, but I think my question would apply to all types of roasters.
At first, I was using stock profiles on the 1600+ just to get used to it, and then began to manually "profile." Using 200g batches, I was able to get to first crack in 8 minutes, and was cutting the heat to allow it to develop on it's own through the exothermic reaction, and cutting just after 9 minutes. Come to find out later, I was cutting too much heat, first crack was falling off too soon (probably not finishing), and my roasts were all WAY too bright, as well as grassy. Finally I read about Scott Rao's DTR, and how long others said first crack should last (60-90 seconds). After lots of tweaking, I found a way to achieve this ( and was getting WONDERFUL fully developed roasts, but not a single one of them was under a medium roast. I usually prefer lighter roasts.
Today I just tried a smaller batch size to get to 1C sooner with the limited energy output of the behmor, and had success! It got to first crack in 7 minutes 10 seconds, and I cut at 8 minutes 45 seconds, handling the heat the same way as before (cutting drastically to P2 when first crack picks up, then going back up to P3 for the remainder of the 20% DRT for good development). When I got the beans out of the roaster, they looked almost identical to the roast that took over a minute longer, and had lost the same percent of weight. I haven't tasted them side-by-side yet, and I'll update this thread when I do.
So (finally) here's my question. What I WANT is a light coffee without sacrificing development. I thought that by making the roast shorter and thereby giving it less time after first crack the end result would be lighter, but that doesn't seem to be the case. Am I missing something, or do I need to abandon the notion that a well-developed coffee NEEDS 20% of its time after first crack begins? Was I right in theory to get to first crack sooner, but I messed up my smaller batch and just applied too much heat and ended up at the same roast level? Am I just understanding the process wrong and lighter roasts have inherently less development? Or am I simply limited by the Behmor? Should I expect a roast that hit 1C sooner but finished at the same temp and DTR to be different from the one that took longer?
I should add that I read the entirety of the recent thread "what's a light roast?" and perhaps it's as simple as my senses and the agtron definition of "light" disagreeing.
Thanks in advance for helping clear this up for me.
"Wait. People drink coffee just for the caffeine??"