Hello! Thank you all for the responses. Apologies for the late replies here.
Some answers and clarifications:
- by "soot", maybe I mean ash? Combustion appears to be complete, but I don't know how to tell. The wings were evenly (very evenly, it was unusual) coated in a light gray powder that mostly wiped off
- the lid vent and all three bottom vents were fully open through the entire bake; by "covered", I meant we left the lid on
- it was a bit breezy, but I don't think we had any gusts?
Is it possible that flare-ups could cause disturbance in the ash, maybe timed with a little breeze? I'm not sure how though, because the grease drippings fall down on the kettle and sizzle, while the ashes were below the coals. Now that I recall, we did not fully clean out the grill when starting this bake, there was some ash at the bottom. But I'm not sure why this would such an issue, because the coals themselves create ash during the bake anyway? I do recall when we took the lid off after the first 10-12 minutes, there was particulate floating around but didn't think much of it since he wings looked okay. It was the second inspection when they had that sooty or ashy appearance.
Current theories:
- we began the bake too early becore
- gust of wind
- running with everything open created a very strong internal convection that caused ash to be distributed
- burnt seasoning
For the last theory... I forgot to include in my original post that we added paprika when seasoning the wings with the oil, salt, and pepper... with vents fully opened, maybe it got too hot and the paprika burned... ? I wish I'd taken a photo, the color was so unusual.
Thanks again for reading
We plan to try again this weekend, not sure whether we'll do the vortex or try a different method.