Did someone share one of my old videos this morning? It's also available on PeerTube:
https://video.typica.us/videos/watch/a4aecb05-2e2b-4b80-a532-b1a78155139b
One of the limitations of the new device I've been using is that it constrains its output to a range ~25-95 Agtron gourmet scale, but one of the first significant events in coffee roasting involves that measurement going off the scale (my benchtop analyzer would put it around 130). Decaf coffees, however, often start out brown so they reach their brightest at a reading that's still in range. That inflection from coffee getting brighter to coffee getting darker is where tasteable chemistry starts
Author of Typica software for coffee roasters.