Combine all ingredients in a small pot over medium heat and bring to a simmer.
Simmer the sauce for 10 to 15 minutes. At this point, the sauce should be thickening up, but still a little bit thin.
Remove the pot from the heat and allow the sauce to cool. Store the barbecue sauce in a sealed container in the refrigerator.
Notes:
This is supposed to be a thin BBQ sauce, not a really thick and sticky sauce. You can simmer the sauce for double the amount of time to thicken the consistency. Be aware though that the sauce consistency when it is hot is going to be a lot thinner than after the sauce has cooled in the refrigerator. It will thicken as it cools.