I’ve commented on the inherent variation in roast level that comes with using an air popper. But you’re right about it being especially obvious in a dark roast!You're using a popcorn popper right? Maybe it's just because of the types of beans you are usually roasting, but I'm surprised how uneven many of the roasts you post are. I usually assumed it was just the typical naturally processed light roast thing, but my roaster would never have anywhere near that type of variation with a dark roast. Are you getting plenty of agitation? Again, it could just be the bean and I'm certainly not criticizing, just trying to understand where the unevenness comes from.