Though you may have heard the terms grilling and barbecuing used interchangeably, there's a distinction between these two very different cooking techniques. We define grilling as very hot, fast cooking directly over and close to the heat, with little to no smoke. Barbecuing, on the other hand, refers to slow cooking with low, indirect heat and the addition of wood smoke. Here, we'll focus on the technique of barbecuing on a charcoal grill and how it produces tender, smoky brisket, pulled pork, ribs, and more.
How does barbecuing tenderize tough meats?
Cuts of meat that come from the more exercised muscles of an animal are tougher primarily due to connective tissue, a transparent protein that provides structure around and between long, thin muscle fibers. As in all low, slow cooking methods, enzymes in the meat called calpains and cathepsins activate and begin to break down the tough connective tissue, making the meat tenderer. This effect continues until the meat reaches a temperature of about 125°F, at which point the enzymes are deactivated. At about 140°F, the connective tissue begins to shrink and squeeze moisture from the muscle fibers, but since the enzymes have partially broken down the connective tissue, its weaker contraction squeezes out less moisture, and the meat remains relatively juicy. At about 160°F, collagen, a component of the broken-down connective tissue, begins to bond with water in the meat, transforming into gelatin. This continues until the muscle fibers reach about 200°F, when they easily separate, becoming "fall-apart tender," and are coated with gelatin and fat, which increases flavorful and textural sensations of succulence and tenderness.
Why does meat sometimes seem to stop cooking?
When meat's internal temperature reaches 150°F to 170°F, it can hover there, sometimes for hours. This "lag time" or "stall" seems to be caused primarily by evaporative cooling, in which the water in the meat gets driven to the surface, where it evaporates and cools the surface, much like evaporating sweat on your skin makes you feel cool on a hot summer day. This surface cooling continues until the meat starts to run out of moisture and the surface dries, forming a crust, or "bark." Then the meat's internal temperature begins to rise again.
What fuel is best for barbecuing?
Seasoned hardwood logs or chunks, because they have the most potential to release flavorful smoke. In general, alder, apple, cherry, maple, oak, and pecan produce mild-tasting smoke, while hickory, mesquite, and walnut produce stronger-tasting smoke. (Avoid cooking with soft, resinous woods such as pine, which release smoke with harsher, sootier flavors.)
After seasoned hardwood, charcoal is the next best fuel. Charcoal is wood burned in the absence of oxygen, a process called pyrolysis, in which most of the wood's organic materials are removed, leaving behind primarily carbon, known as char.
When pyrolyzed hardwood is broken into small chunks, it is called "lump charcoal." This lightweight form of charcoal burns quickly, so it's generally not preferred for slow barbecuing. Charcoal briquettes, on the other hand, are made with compressed sawdust, mineral char from coal, and limestone bound together with starch; the mineral char prolongs the burn. When you need more than 45 minutes of steady heat for barbecuing, charcoal briquettes tend to provide a more consistent temperature than lump charcoal.
How does barbecuing create smoky-tasting food?
Wood consists of three main components: cellulose and hemicellulose, which are large sugar molecules that form the structure of the wood's cell walls; and lignin, a polymer that strengthens these walls. As the wood burns, its cellulose and hemicellulose essentially caramelize, creating sweet, fruity, and flowery flavor components, as well as brown colors. The lignin transforms into smoky, pungent compounds and spicy compounds with aromas like clove and vanilla. These smoke flavors mix with water on the surface of food, and that's mostly where you taste them.
Why does my barbecue recipe call for soaking wood chips?
Many people believe that wet wood chips produce more smoke than dry ones, but this isn't the case. Soaked wood chips produce the same amount of smoke flavor as dry chips; they just take longer to do it. As wet wood chips begin to dry out and ignite, any water remaining on their surface evaporates into steam, creating thick clouds that look great but add little smoke flavor to your food. Smoke flavor doesn't start to develop until the elements in the wood combust, which can't occur while there's water present. In fact, the really flavorful gases from combusted wood are barely visible but have a pale blue haze; this is why barbecue gurus talk about "blue smoke" as the Holy Grail. Rather than soaking wood chips, a better way to prolong the smoke is to place the wood chips on a cooler part of the fire and to limit airflow in the grill to delay combustion.
Why do recipes call for a water pan to be placed in the grill?
To create steam, which does several things:
- Steam tenderizes tough meats. Collagen in the meat's connective tissue needs water to dissolve and turn into succulent gelatin.
- Steam helps smoke flavor stick to food. In a barbecue filled with steam, moisture condenses on the meat, helping to cool the meat's surface (see the explanation of evaporative cooling). If aromatic smoke is present at the same time, the smoke particles move from the hotter air to the cooler meat surface via thermophoresis, a physical force that moves particles from warmer to cooler areas. When you keep the atmosphere in your barbecue moist, the surface of the meat is constantly cooling and able to take on more smoke flavor.
- Steam helps to create a deeper "smoke ring." When you cut into barbecued meat, you're likely to see a bright pink border just under the crust. Here's how this "smoke ring" develops: Smoke is an airborne dispersion of microscopic particles in a vapor of combustion gases, including carbon monoxide and nitrogen monoxide. When these gases dissolve in the water on the surface of barbecued meat, they prevent myoglobin, the red pigment in meat, from turning gray, as it normally does when red meat cooks. But the gases can't penetrate very deeply into the meat's surface because of the constant drying of the crust. Adding moisture via a steaming pan of water (or a mop, baste, or spritz) can help the smoke ring penetrate deeper by keeping the meat's surface moist and moving more smoke from the air to the meat.
When should I salt the meat for the best flavor?
Before you cook it. Salt breaks down and opens protein chains in meat, exposing more bonding sites for water. And as you now know, the moister the meat is, the better it's able to attract and hold the flavorful elements in smoke. How far in advance you should salt it depends on what you're barbecuing. For relatively quick-cooking foods like ribs or chicken pieces, which need less than a couple of hours to cook, seasoning up to 24 hours ahead gives the salt ample time to do its work. Bigger, tougher cuts that need more time, such as a brisket or pork shoulder, can be salted right before cooking.
When should I sauce my barbecue?
Barbecue sauces typically contain sugar and will burn if exposed to high or prolonged heat, so brush your food with sauce only at the very end of cooking. (Some barbecue aficionados prefer to sauce at the table only, after the food comes off the fire.) If you want to add moisture earlier so that the meat takes on smoke, use a pan of water to produce steam, or a mop, basting brush, or spray bottle to apply unsweetened liquid, like beer or cider vinegar, directly on the meat.
David Joachim and Andrew Schloss are the authors of the award-winning reference book The Science of Good Food. Their latest book, Grill School, is due to be released in June.