Hope a coffee aficionado can help me out here. I decided to try buying beans from a local roaster who supplies several coffee shops around the city. I bought 3 different bags of single origin beans. I noticed some very uneven roasting among all the bag, but the attached picture is what surprised me - this yellow flaky center among all the beans that I've never noticed before when buying beans. When the beans are ground, the yellow flakes persist with the grounds.
Anyone know what these yellow centers indicate? Are they generally present and most major commercial roasters simply do a better job of cleaning them away? A sign of poor roasting? Or worse yet, a sign of old or poorly dried beans?