From America's Test Kitchen
Dry, flavorless ribs are a true culinary disaster. More often than not, baby back ribs cooked at home come out tasting like dry shoe leather on a bone. We wanted ribs that were juicy, tender, and fully seasoned, with an intense smokiness, ribs that would be well worth the time, money, and effort.
Meaty ribs—racks as close to 2 pounds as possible—provided substantial, satisfying portions. For ribs that are so good and moist they don’t even need barbecue sauce, they must be brined first—we used a salt, sugar, and water solution—then rubbed with a spice mix before barbecuing. Chili powder, cayenne pepper, cumin, and dark brown sugar formed a nice, crisp crust on the ribs and provided the best balance of sweet and spicy. For even more flavor, we used wood chunks and the “low and slow” cooking method. This extended amount of time on the grill made for tender baby back ribs with an intensely smoky flavor.
For a potent spice flavor, brine and dry the ribs as directed, then coat them with the spice rub, wrap tightly in plastic, and refrigerate overnight before grilling. If you're using a gas grill, leaving one burner on and turning the other(s) off mimics the indirect heat method on a charcoal grill. Use wood chips instead of wood chunks and a disposable aluminum pan to hold them.