From America's Test Kitchen Season 9: Weeknight Summer Supper
Grilled chicken breasts aren’t all that easy to get right. Burnt, limp skin and sooty, parched meat are too often the reality. The perfectly grilled chicken breast should boast tender and succulent meat and crisp skin.
Brining the chicken breasts for an hour or so before grilling helped ensure juicy, seasoned meat throughout, but consistency was an issue. We needed to focus on developing a precise grilling technique to minimize temperature fluctuation, thereby ensuring perfect meat every time. To do so, we created a sort of oven within an oven by covering the chicken with a piece of foil before closing the lid. This approach, combined with cooking the breasts skin side down on the cooler half of a modified two-level fire, finished cooking all six of the chicken breasts simultaneously. But we had one remaining problem: flabby skin. To solve it, we revised our plan and developed a three-step dance: We cooked the chicken on all sides over the hotter part of the grill until lightly browned; moved it to the cooler half and covered it with foil; and finished the breasts on the hotter side, cooking on both sides until the skin was brown and crisp.
To help ensure that each breast finishes cooking at approximately the same time, buy pieces of similar size. Barbecue sauce can replace the optional glaze in step 4.