I heard this wonderful show on NPR in April about cooking, and what's really happening (scientifically as you cook) on the Kojo Nnamdi Show that I listen to locally on WAMU.
Anyhow, they had a show with Robert Wolke in April with who is a Washington Post columnist of "Food 101"; author of "What Einstein Told His Cook"; "What Einstein Told His Cook 2" and a professor emeritus of chemistry at the University of Pittsburgh.
I love the Kojo show generally, and this one was focused on food, and grilling. You can listen to it at this link: Kojo Grills with Charcoal
and to let out part of the show, Robert Wolke prefers hardwood charcoal because it's hot and dry.