Salt and Pepper Spare Ribs

Step 1
Mix salt, black pepper, white pepper, cayenne, and garlic powder together in a small bowl. Set spice rub aside.

Step 2
Stir vinegar and Dijon mustard together in a small bowl.

Step 3
Place ribs on a foil-lined baking sheet. Turn the ribs over so that the meat side is down. Use the tip of a small, sharp knife to make some very shallow slashes every few inches through the membrane that covers the ribs. Poke the knife 3 or 4 times between each rib bone, about 1/4 inch deep.

Step 4
Brush about 1/2 of the Dijon mustard mixture on top. Sprinkle with about 40% of the spice rub. Turn the rack over and brush on the rest of the mustard and vinegar mixture. Sprinkle on the rest of the rub, reserving 1 or 2 teaspoons in case you want to use it to season the cooked ribs later.

Step 5
Refrigerate the ribs, uncovered, 4 to 12 hours before baking.

Step 6
Preheat the oven to 300 degrees F (150 degrees C). Remove ribs from the refrigerator.

Step 7
Cook in the center of the preheated oven for 1 1/2 hours. Remove from the oven and baste with the pan drippings. Continue to cook until very tender and the tip of a knife slides in very easily, about 1 1/2 hours more.

Step 8
Remove from the oven, baste again, and let ribs rest for 15 minutes before cutting and serving.