Baby-back ribs are more lean and tender than pork spare ribs. They are cut higher on the rib cage, closer to the backbone, which is near where lean center-cut roasts and chops are found. The best ribs are slow-cooked on a charcoal grill with wood chips for added flavor, but you can get good results from baking them in an oven as well.
Ribs slow-cooked with indirect heat and a light spice rub have the best flavor, according to America's Test Kitchen. Whether you are using a gas grill or charcoal, heat one side of the grill and cook the ribs on the other. Keep the grill between 275 degrees and 300 degrees for four hours, turning the rack every half hour. Flip the ribs and turn them 180 degrees to alternate the side facing the fire.
Ribs cooked without added moisture will inevitably become dry, whether they end up tough or tender. One way to avoid this is to soak them in a brine solution before grilling. Another way is to boil them for 30 minutes before adding the spice rub and finishing them on the grill. Use the same indirect heat method as before for the remaining three to three and a half hours. Ribs that are rendered will lose some of their natural flavor along with the fat that boils off.
When cooking ribs in the oven, keep a pan of water on the rack below the ribs to help keep them from drying out. Cooking times will vary depending on the temperature setting you use. Three to four hours at 300 degrees should produce the best results, but if you are in a hurry, one to two hours at 375 to 400 degrees will work. You will end up with slightly tougher ribs that may not separate easily, but they will be done and have a good flavor.
- Here in America's Test Kitchen; Editors of Cook's Illustrated Magazine; 2002