The secret to making great barbecue is simple—good airflow. Wait. Actually, the real secret—this is so obvious that people forget it—is a great piece of meat, because what goes in your smoker is what comes out.
So there's no one secret. There are a bunch, and sometimes they contradict one another. This is what I'm learning at the seventh annual Barbecue Summer Camp, a weekend immersion into the science of barbecue put on each June by Foodways Texas and the Meat Science Section of the Department of Animal Science at Texas A&M University in College Station.