Whisk the ketchup, apple cider vinegar, water, brown sugar, yellow mustard, and Worcestershire sauce in a medium saucepan until smooth.
Stir in the paprika, garlic powder, onion powder, black pepper, cayenne pepper, celery seed, and kosher salt until evenly combined.
Bring to a gentle simmer over medium heat, then reduce to low and cook, stirring occasionally, until slightly thickened and glossy, 15–20 minutes; the sauce should coat the back of a spoon.
Remove from heat and let stand 10 minutes to settle and thicken slightly. Use warm for glazing during the last few minutes of grilling, or cool completely and refrigerate in a sealed jar for up to 2 weeks.