Quote Originally Posted by UncleChester View Post
"Fine or medium" are the usual given grades for the charcoal, and mixed in with the substrate not a separate layer.

I use the lump charcoal for the bbq from Home Depot and hammer it to be pretty fine. If you go the "smash your own route" make sure the stuff you get contains only charcoal (no lighter fluid, Duraflame makes something suitable) and do the smashing outdoors and with the charcoal in a bag to contain the dust, this is messy.
That's what I needed to know .. I guess I have some more smashing to do lol. I have already mixed the other contents and I have to say that the mixture feels, smells and looks great.