According to the Hearth, Patio, and Barbecue Association (HPBA), about 80 percent of American households own barbecue grills. Most popular days for grilling, says the HPBA, are Labor Day, Memorial Day, and the Fourth of July—though a good 60 percent of grill owners grill steadily year-round, undeterred by snow, rain, heat, or gloom of night. Real enthusiasts even cook their Thanksgiving turkeys and Christmas dinners on the barbecue grill. And Americans are not the only ones who love a flame-broiled meal (see Getting Our Global Grill On.)

So what is it about grilling that makes food so yummy? Why is boiled beef so blah, but its grilled cousin so brown, aromatic, tasty, and generally delicious? It’s all in