Combine the butter, water, vinegar, brown sugar, garlic, salt, pepper, and cayenne pepper. Bring the mixture to a simmer. Remove from the heat and set aside.
Cut the pork ribs into serving-sized portions and place them on a rack in a roasting pan, meaty side up. Roast the ribs uncovered for 1 1/2 hours. Brush with the sauce for 45 minutes longer, basting with the sauce mixture every 10 to 15 minutes.