The 321 rib method is a foolproof cooking process to get the best fall-off-the-bone ribs ever — and it’s super easy to pull off once you try it a few times. They’re called 3-2-1 ribs because of the cook times for each step: 3 hours on the grill, meat side up, low and slow cooked at 225° F. 2 hours wrapped in foil, bone side up, with liquid to keep the meat juicy and to add more flavor. 1 hour meat side up smothered in BBQ sauce to complete the process.