What Do Direct and Indirect Heat Mean for Grilling?

Direct heat is the classic way to use a grill. The meat sits directly over the coals and receives heat through both radiation and contact; its surface browns within a few minutes, forming the crust that gives it a roasted flavor. This method is suitable for cuts no more than 3 centimeters thick: meat patties, wings, thin steaks, kebabs on skewers, vegetables, and bread. With thicker cuts, the outside burns while the inside remains raw because the time needed for heat to reach the center is longer than the surface can withstand.

With indirect heat, the coals are banked on one side of the grill, the meat is placed on the empty side, and the lid is closed if there is one. Heat now circulates around the meat rather than coming from below; the temperature drops but becomes more even. This is the right method for thick, bone-in cuts: a whole chicken, leg of lamb, ribs, and thick chops. The meat cooks through without drying out or burning. It takes longer, but the result is close to oven-roasted meat and still has a smoky flavor. On a grill without a lid, a wide tray or foil placed over the meat can create a similar effect.

The most skillful approach is to use the two methods in sequence; this is called two-zone grilling. Sear a thick cut over direct heat for a few minutes on each side, then move it to the indirect-heat zone and leave it there until it reaches the target internal temperature. You can also reverse the order: warm the meat slowly over indirect heat, then move it over the coals for the final 2 minutes to brown it. The second sequence gives a more even cross-section and carries a considerably lower risk of burning.

The setup is simple. Once the coals have ashed over, use tongs to bank them on one half of the grill and leave the other half completely clear. On small grills, spread the coals over two-thirds of the area and leave one-third empty. To keep dripping fat from catching fire, place an aluminum tray on the empty side and pour a little water into it. On covered grills, the air vents control the heat: closing them down lowers the temperature, and closing them completely will eventually extinguish the coals.

Flare-ups can happen in each of the two zones; the only solution is to move the meat temporarily. Sprinkling water on the coals stirs up ash that can stick to the meat, so do not do this. Flare-ups are usually caused by dripping fat, so trim excess fat beforehand. Use a thermometer to check doneness on the grill as well: poultry to 74°C / 165°F, a whole cut of red meat to 63°C / 145°F followed by a 3-minute rest, and ground-meat patties to 71°C / 160°F. It also helps to leave an empty area at the side of the grill; when flames flare up, move the meat there and wait for them to die down.