Smoke rings are produced by a chemical reaction between the meat and the penetration of the smoke. You may see a smoke ring on meat barbecued over a wood fire. It is a pink color that extends from the outside surface into the meat. Its thickness is dependent on several factors, such as the type of smoke and the duration of smoking.
There are many interpretations of the term “barbecue.” Some people use it to describe a social gathering and cooking outdoors. Others use it to describe grilling food. We use the term to describe meat that is slow-cooked using wood smoke to add flavor. There is equipment designed just for this type of cooking. Barbecuing is cooking by using indirect heat at low temperatures and long cooking times. It is the smoke from the wood that gives barbecue its unique flavor. Barbecuing is not grilling. Grilling is cooking over direct heat, usually a hot fire for a short time.
Any wood from a nut or fruit bearing tree can be used. Softwood should not be used. The resin in conifer wood such as pine, fir, spruce, etc. will ruin the meat. The following types of wood are commonly used for smoking: hickory, oak, maple, mesquite, alder, pecan, apple, cherry, pear, and peach. Fruit woods tend to impart milder, slightly sweet flavors to meat, while woods like hickory, oak, and mesquite impart stronger flavors.
Barbecue is an evolution of cooking technique that involves using the tough, cheaper cuts of meat and cooking them until they are tender. Brisket comes from the breast area of a steer that does a lot of work and tends to be very tough. This is also true for pork shoulders (the forelegs of the pig). These cuts of meat have a lot of fat and collagen, the material that holds the muscle together. Long slow cooking transforms the collagen from a tough material to a gelatin that dissolves. This can take hours at temperatures of 250 degrees or lower.
There are two types of smoking: cold and hot. Cold smoking is a method of preserving meat. Meat or fish is typically soaked in a brine solution and then it is smoked cold at temperatures of round 100 degrees. Hot smoking is really smoke cooking. It is typically done at temperatures in the 200-250 degree range, and will not add any preservation to foods.