“Two-zone fire” is treated as a single, generic piece of grilling advice online, but America’s Test Kitchen’s own testing actually distinguishes between two meaningfully different configurations, built for two different jobs. Using the wrong one for a given cook — or not realising there is a choice at all — is a common reason a “two-zone setup” does not produce the result a recipe is expecting.
Setup One: The Two-Level Fire
The two-level fire is the gentler of the two configurations. For charcoal, it means evenly distributing two-thirds of your lit coals over half the grill, then spreading the remaining third in an even layer over the other half. For gas, it means leaving the primary burner on high while turning the other burner or burners down to medium, rather than off. The result is two zones that are both actively hot, just to different degrees — a hotter area for searing, and a noticeably cooler, but still directly-heated, area to finish cooking more gently. This setup is commonly used for foods like thick chops and bone-in chicken pieces, where you want a real but more moderate difference between the two sides, not a fully off zone.
Setup Two: The Modified Two-Level (Half-Grill) Fire
The half-grill fire is a more extreme version of the same basic idea. For charcoal, all the lit coals go on one half of the grill in an even layer, leaving the other half completely free of coals — not banked down, empty. For gas, the primary burner is set as a recipe directs while the other burner or burners are turned off entirely, not just down. This produces one genuinely hot zone and one indirect zone with no direct heat source underneath it at all, which is a fundamentally different setup from the two-level fire’s “hot and less hot” arrangement.
Why the Difference Actually Matters
The half-grill fire’s fully indirect cool zone is specifically what makes it useful for fatty foods and flare-up-prone cuts: when fat dripping onto hot coals causes a flare-up, having a genuinely coal-free zone gives you somewhere to move the food immediately, rather than a “cooler” zone that is still sitting over active coals and could flare up itself. It is also the setup behind the classic sear-then-finish approach for thicker cuts: brown the food hard on the fully hot side first for a proper crust, then move it to the completely indirect side to finish cooking through without burning the exterior further. For something like chicken breasts, the same logic runs in the other direction — cook gently on the cool, coal-free side first, then finish with a quick, hard sear on the hot side right at the end.
Choosing the Right One for Your Cook
As a practical rule: if a recipe or technique calls for a real off-zone — somewhere to escape flare-ups entirely, or to finish a seared piece of meat with genuinely indirect heat — the half-grill fire, with one side completely free of coals or one burner fully off, is the correct setup, not a two-level fire with coals or medium heat still under the “cool” side. If instead you want two zones that are both usably hot but at different intensities, for something like bone-in chicken pieces or thick chops that need real heat on both sides just at different levels, the two-level fire, with coals or burner heat maintained on both sides, is the better match.
Setting Either One Up Correctly
For charcoal, the key practical difference to get right is whether coals go on both halves at different depths (two-level) or entirely on one half with the other genuinely bare (half-grill). For gas, the equivalent distinction is turning unused burners down to medium (two-level) versus switching them off completely (half-grill). Treating “turn the other burner down” and “turn the other burner off” as interchangeable is the single most common way this setup gets done incorrectly, and it produces a noticeably different, and often disappointing, result compared with what a specific recipe was actually designed around.
Sources
- America’s Test Kitchen. “The 5 Best Grill Setups for Your Summer Grilling.” americastestkitchen.com