1. Place ribs in a large bowl or resealable plastic bag, set aside. Mix together vinegar, water, oil, brown sugar, salt, red pepper flakes and cayenne pepper until salt is dissolved. Remove 1/2 cup marinade; set aside. Add remaining marinade to ribs; seal bag and marinate for 4 - 6 hours in the refrigerator. Remove ribs from marinade; discard marinade.
2. Prepare medium-hot fire; grill ribs over indirect heat for 50 to 60 minutes or until pork is tender and the internal temperature reaches 160º F. Baste ribs with reserved sauce mixture during last 15 minutes of grilling.
2 pounds boneless country-style pork ribs
2 cups apple cider vinegar
1 cup water, cold
2 tablespoons vegetable oil
1/4 cup brown sugar
1 tablespoon salt
1/2 teaspoon crushed red pepper
1/2 teaspoon cayenne