People can take great pride in their personal recipes, whether it's a family recipe for chili or a special dish. This also holds true for barbecue recipes. The ability to thicken a homemade barbecue sauce without affecting the taste is a skill that every aspiring barbecue chef should add to his repertoire of cooking tools. You can use cornstarch or flour to accomplish this without disturbing the flavor of your sauce.
Add 2 tbsp. of flour to 1/4 cup of cold water, for each cup of sauce you wish to thicken. You can also use a mixture of 1 tbsp. cornstarch and 1 tbsp. of cold water.
Mix the combination thoroughly. This will prevent lumps from forming in your sauce. Stir the combination into your barbecue sauce.
Cook the sauce over medium heat on your stove, while continuing to stir. Maintain the process until the barbecue sauce appears thicker and begins to bubble. Stir an additional minute for the flour solution, and two additional minutes for the cornstarch.