Originally posted by Lew:
I don't use KC and I've never seen Stubbs compared to KC for ash production anywhere else, but Nakedwhiz.com compared K to KC and found that they produce similar amounts of ash and twice the amount of Wicked Good, which is similar to Stubbs (natural charcoal with a vegetable binder). Wicked Good also burned longer.
It's not scientific, but in my grills & smokers, K leaves considerably more ash than Stubbs, and if KC leaves 92% as much as K (as the above test says), I would guess it would leave more ash too.
For what it's worth.