WOOD ON A CHARCOAL GRILL
Wood chunks are the easiest way to add smoke flavor when cooking over charcoal. You don't want the wood to catch fire and give up all its smoke at once. Ideally, the chunks should smolder slowly, releasing smoke for as long as possible. We found that soaking chunks adds enough moisture to the wood to prevent it from catching fire as soon as it is placed on the charcoal.
If using wood chunks, soak as many three-inch chunks (each the size of a tennis ball) as directed in each recipe in cold water to cover for one hour. Drain the chunks and place them directly on the lit pile of charcoal.
If you can't find wood chunks, small wood chips may be used. To keep the chips from burning up too quickly, we found it best to wrap them in a foil packet. (There's no need to soak these chips; the foil protects them from catching fire too quickly.) We tried soaking the chips and throwing them directly onto the coals, but they caught fire immediately. The same thing happened when we placed the chips in an open foil tray on top of the coals—an open tray does not provide enough protection for the chips and can tip over if placed on an uneven pile of charcoal.
If using wood chips, follow figures 5 and 6 to wrap chips in heavy-duty aluminum foil. Note that regular foil does not offer enough protection and the chips can catch fire.