Combine in a medium to large non-reactive saucepan with a glass lid: 2 cups Heinz or Hunts Ketchup, ¼-½ cup yellow mustard, ¼ cup apple cider vinegar, ½ cup firmly packed brown sugar, 3 tablespoons Worcestershire sauce, 2 tablespoons chili powder, 1 tablespoon black pepper, 1 tablespoon onion powder, 1 tablespoon garlic powder, 2 teaspoon celery salt, 2 teaspoons liquid smoke, ¼ to ½ teaspoon of cayenne pepper.
Place over medium heat, stirring aggressively until starting to boil, being careful to avoid splatter. This stuff is thick and will burn you. Reduce heat to low, cover, and simmer. Occasionally remove from heat and stir well. Please remove from heat before stirring to prevent splattering and burns.
Simmer for 30 minutes. As little as 15 minutes works fairly well, but 30 is better for bringing the flavors together.
