Well, that is a good point Carolina, I think it causes some kind of "chain reaction", or "osmosis" type of effect that ceases at a certain depth probably dependant on temperature or some other factor. Kind of like a hot water burn would affect your skin to a certain depth without the water actually "penetrating" it. Also, "over smoking" can be percieved differently by different people. Some folks tolerate the flavor more than others. I for one, have never tasted "over smoked" meat. I think that the point about burning a clean, fire is certainly valid. Under seasoned, or wet wood certainly would cause "dirty" smoke. In addition, as Bubba so deftly notes, a hotter fire will burn cleaner and more completely. The hotter the fire, the more complete the combustion and thus, the fewer the residual particulates. I think also, as Bubba mentions, the smaller the chamber, the less the air circulation allowing for the precipitation of those particulates onto the surface of the meat because of prolonged contact. I am not a scientist, but it seems quite logical. to me. Not picking on Witt, he knows his stuff, but the concept that thin , wispy smoke "penetrates" a dense plug of meat just does not make sense!!!