Deven, no fear, I dont take anything personally and … also my belief is that if we just pat each others back saying how great everthing is, we wont be moving forward and learning. So - Thank you for you detailed comments .)
Also very nice links to materials that I can study, I allways appreciate this … Thank you!
Regarding the cross section pictures, I think the TP2 was just an error when I took the picture, that it moved to an angle where it reflected the light, it looked very simillar to the A profile and before I took the picture it looked all right, but it was probably too late evening and I focussed only on A and LiteBrite so … did not notice the reflection untill it was uploaded.
Of cause, I am fully aware that any profiles I use for my test roasts are not custom tailored to the beans. I dont even try to do this at the moment, as I said I think more about the large scale effects and not so much about manipulating one point or another … too early for that, at least for me. So …sure … I did not expect any of them to be like the perfect one. What I wanted to test was, how different the very short and very long profile (LiteBrite and A) behave in comparison to my go to profile for africans which is the TP2 (its actually the same as LiteBrite which is just moved to a slightly higher temperature if I understood it correctly). So I intentionally did not try to stop each roast at a point where I would “feel” it to stop, but stopped it cca 30s after crack stopped, which is my usuall mid point of where I stop. Clearly the fast roast ended a little less developed (well actually its not so little difference :)) ) and the slow roast ended a little more developed, but that is what I wanted to see.
Today we tasted the outcome at the roastery (espresso, which we allways do with my sample roasts) - all very clean and nice … the A profile felt a bit dark but not to a point where I would say its too dark to my taste, just a hint of that. And it had the acidity in a rounded form, sort of dried fruit acidity. The TP2 was the best, even cleaner, the acidity felt brighter and sharper, still having that roundness but from it some spiky curly protrusions of brightness … body still simillar volume as the A profile. I would just add 5-10s if I wanted a bit more body there and would be very happy with it.
The LiteBrite needed a little more development, very simillar acidity to TP2, but way less body, and some hints of underdeveloped taste, half yellow half green I would call it … on the edge of not being a nice taste but still acceptable as a part of the taste to a point I would say. I would think adding maybe 30s to this one would take it out of that region and into more body but still not too much sweetness and caramels region for me …
I understand what you mean by having those roasty taste from that defect you wrote about - I have to say I am so much used to having that little hint of that even on the best roasts, that I did not even thought it can be totally removed - knowing now that you managed to do it I will also try to get rid of this, as it would clean up and sharpen the tastes a lot.
Do you have some idea about how to make the overall colour the same? (now I dont talk about the small dark sports, but the lighter outside layer and darker inner layer - on the LiteBrite its gradient but still its there too) I think I can not use much less air and still have enought movement of the beans, but its there on the slow and fast roast without too much change in ballance I think, just the way its distributed is more sharp with A profile.
Regarding taking picture on iphone, you can buy attachable microscope lens, that uses the internal optics and sensor if iphones camera so you would get better picture actually (these have low resolution, but its usb microscope that uses its own sensor). I have purchased this one because it was available as an addon to my tsprof shapener so I just added it to check it out.