Okay, I’ve done two, with nearly identical outcomes: a fine network of relatively shallow cracks in the “capsule”, the thin layer of fine particles which encapsulate the core. I’ve been rereading various accounts on how other people make dorodango, and have noticed a couple of differences which I think I am going to test.
I suspect now that I’m being too timid in my initial drying of the core. After forming the wet inner core, you then sprinkle on relatively fine, dry dust until it won’t hold any additional material. What I was doing was then cycling this in a plastic bag, essentially drying the core very slowly, while adding additional finer and finer material. Eventually, when I did dry out this fine material, it was relatively inflexible, and as the core shrank slightly, it tension cracks. I’m now wondering if the bulk of drying shouldn’t happen while the outer skin is still relatively coarse. So, my next ball will be worked relatively longer in its primitive stage, and will be allowed to dry overnight. One account says that if it cracks, it will likely do so in the first 30 minutes of this stage.
I think I am going to ditch the soil that I purloined from Golden Gate park as well. It has a lot of faintly greasy black silt embedded in it, which is quite slick and messy. My normal backyard dirt was easier to work. I may also buy a bag of fire clay just to see what I could do with a 50/50 clay sand mixture.