I'll probably scrap all these and redo the work with a white background, because I intend to add photo's as I go along and prefer consistency in white balance/appearance, but I want to share some images and thoughts about how the beans react to the environment inside the Quest M3 versus a traditional gas drum roaster with better convective properties.

These were taken on a pink piece of paper for contrast, but I'll probably redo it with white, for white balance sake. I didn't bust out the tripod, but these were taken with an L series Macro on my Canon and can be magnified quite a lot. The point of these photos is to show how a beans that happened to be roasted to the same percent weight loss can look quite different both by surface appearance, cut appearance, color, etc. You wouldn't believe that both of these coffees are 13.0% weight loss. There isn't anything profound or earth shattering here, because I didn't control for many variables. I might try to put something together more objective going forward.

The Quest finishes or develops coffee faster than a traditional drum roaster in my experience and I'm convinced it's due to its higher degree of conductive heat transfer to the beans, likely due to it's less effective convective properties compared to a gas drum. Regardless of fan or heat settings, if you map the post first crack development time on the Quest and compare it to pretty much any other gas drum roaster with the same post first crack development time, you'll often see the beans take on far more development in terms of color and weight loss, expansion, etc. I can't roast a batch on the Quest anywhere as easily as I can on the 1 kilo gas drum. I can stretch a first crack period a lot gentler, with less fuss as well, but that's not really poignant to the topic.

Here's some shots of a bean with 13.0% weight loss, that had a 2 minute post first crack phase on the gas drum roaster. Note the relatively even bean color throughout compared to the following Quest roasted coffee. This is one of the Colombian Cuaca beans from the Focus on the Roast competition, my coffee I submitted.




A bean from the Quest, with only 45 seconds of post first crack time, also 13.0% weight loss and visually even further bean surface development in terms of color, texture, expansion of the flats, etc.




Back to the gas drum coffee, the development looks more gradual, even and thorough to my eyes.




The Quest roasted bean again, the centers appear more like moist dark fudgy centers of brownies.




I'll start including some Tonino measurements to help maybe shed some light as well. These aren't even the same coffee for the two comparisons, so it's sort of a moot point to debate on, but I used them because they are consistently what I'm finding in pretty much any profile, any coffee. The Quest darkens the surface and conducts heat quicker to the bean, whereas the gas drums efficient convective heat seems to give a more even, thorough development, and does so over a longer period of post first crack time.

Nice photography skill Tom!

Though to my eye, it seems the Quest developed the beans more evenly? The beans from Quest seems darker and even throughout; whereas the drum roasted beans has light and dark area/gradient. Or did I read the picture in the wrong order? (pic 1: Drum ; pic 2 : Quest ; pic 3 : drum ; pic 4 : Drum)

What did you use to cut them so cleanly?

Thanks Sam. 1st and 3rd, gas drum, 2nd and 4th, Quest. I'm just starting to throw out some concepts, nothing I'm going to hang my hat on yet. To be of any real utility, I'll need to profile the same coffee on both and either control for the same Tonino measurement, or bean surface appearance, or post first crack time, or something like that, then compare.

I just used a razor blade.