Going out on a limb......suggest the roast is not correct from what I can see on the close-up. (but I could be wrong). Likely to be an under-developed roast situation as opposed to an under-roasted batch, e.g. final temp, time and moisture loss may all indicate sufficient roasting has occurred but the bean itself has not had it's inner core transformed during the roast execution. You may find that grinding a couple of beans results in a rather light shade of brown. That is a reasonable bell-weather on how close the external and internal colours match. If the ground shade is very light, then the only hope might be to let the beans sit for a long time (say 3 weeks) as they may taste pretty sour. Of course, what I am saying here is just a prediction - everything may be OK. As for thermal loss ratios, I don't know what the range is for that appliance. A good guide on commercial platforms is around 16% depending upon roast depth, e.g. just before 2nd crack. Loss is also related to the original hardness and moisture content of the raw coffee and the application of heat in the profile. PNG Peaberry are quite common and I would go so far as to say some of the best coffees I have ever tasted in the past have been PNG Peaberry - incredible complexity, depth and balance - especially some of the top Kimel PB lots. Peaberry are highly sought after because they can, if it's a good lot and in the right hands, stand well above non-peaberry from the same region - they can do so much more. In this regard, the good lots command a price premium in the market. Tanzania and Kenya peaberry are classic examples of everything that is superb about Peaberry - so long as it's a good lot. Roasting peaberry, just like Decaf and Monsoon Malabar, require a different skill and before anyone asks what that is.....sorry, it's a learned skill.
