Whisk together the ketchup, vinegar, sugar, water, Worcestershire sauce, chili powder, cumin and cayenne in a saucepan, bring to a low simmer.
Once sauce reaches a simmer, immediately turn off the heat. Let the sauce cool to room temperature. This can be used as a basting sauce toward the end of the cooking time of your meat or brushed on after barbecuing, with additional sauce served on the side.