You've learned all about what types of woods are best to use on your coals in this tutorial. Now let's get a little bit more advanced...
When you go to the store and purchase bacon or certain cheeses, you may be pleased to see the word "smoked." Is this the same thing that barbecuers do? Well, no. Barbecuers practice smoke cooking, whereas items like smoked cheddar or American bacon are actually cold smoked. In a cold smoking process, items may continuously absorb smoke due to the fact that they're not being cooked with heat per se. Food remains more porous and the surface stays permeable.
Some barbecue chefs allow their meat to smoke for 3 to 4 hours, then wrap in foil afterward. This is because meat is most porous at its raw stage, and therefore it absorbs the most smoke when it's first put on your grill. After a few hours, the meat tenses up and the skin forms a crust. The pores are, for the most part, then closed. Therefore, wood should be added at the beginning of the cooking process and replenished when smoke diminishes. Of course, many barbecue establishments cook with wood the entire time, whereas at home, we put wood pieces over charcoal.
What do you do before adding wood? Soak it in water, of course. But why do you soak it in water?
Soaking for an hour or two does not actually make the wood moist all the way through... moisture probably only goes about half a centimeter deep. However, this is still helpful, as it allows the wood to smolder when it is first put over hot coals. Once you cover the grill, the wood is less likely to catch fire, even when the moisture-infused layer is cooked through. If you neglect to soak the wood, it may just catch on fire before you have a chance to put on the grill lid. The wood will then burn off very fast, not to mention scald the underside of your food.