Things to think about with this recipe: Why butter? Butter has a way of adding just the right touch of silkiness to sauces. Barbecue sauces contain acidic ingredients like tomato and vinegar. Adding the butter at the end tames these flavors a bit and gives it a nice creamy texture. When I say creamy, I don't mean like a cream sauce. You do not have to make this addition; it's a matter of personal choice.