Unless you're a hardcore barbeque fan, you'll likely not cooking ribs all that often. And even less so, if they turn out tough and disappointing. So let's get you on the way to rib perfection. First, the overnight marinade gets absorbed, and the salt and sugar begin the process. Then, a longer cooking time tenderizes the tough connective tissue; Guarnaschelli recommends at least 2 1/2 hours on the grill, making them tender but not yet fall-off-the-bone.