After each roast I manually check the beans, not only for stones but also to take out any 'odd' beans that I spot. That's mostly the beans that remained rather light, yellowish. It's assumed that these result from unripe berries. I see this more frequently in 'pulped natural' / 'unwashed' beans. Today I took the small handful of oddly light beans and ground them the same as the sample of other beans that I roasted in that batch. The production has Tonino #92 and the 'light' ones came out Tonino #116. Quite a huge difference! The light ones also smell odd (stale peanuts). So this hand sorting is a good thing. see also: https://counterculturecoffee.com/blog/optical-sorting-qa On the left, the #92 production, on the right, the #116 'light outtakes' The roast profile. Brazil Pianta pulped natural PS Björn Aarts has a special device to do this automatically: https://youtu.be/rzQXbWZtrIM?t=127 This "Pearl Mini" is not cheap though...