Carolina Style BBQ Sauce

(Vegetarians need to close their eyes now).  Recently I made a pork butt in the slow cooker. (Vegetarians may now re-open their eyes) I wanted to serve it with a BBQ sauce, but I wanted a vinegar based sauce like you can get back in the Carolinas.  This is a combination of several recipes as there appears to a battle between Western Carolina and Eastern Carolina regarding how this sauce should be made.  I combined the two recipes in an effort to bring all of Carolina together...of wait there are still two of them...North and South.  Of well, I am from Georgia and keep them apart makes up look all that much better. Regardless the sauce is vegetarian and can be made with olive oil to create a vegan sauce. 

4 tablespoons unsalted butter
1/4 cup finely minced onion (yellow or sweet) or 3 teaspoons onion powder
1 1/2 cups apple cider vinegar
1/2 cup no High Fructose Corn Syrup Ketchup
1 cup brown sugar
1 tablespoon Worcestershire sauce
1 teaspoon Tabasco sauce

1. In a large sauce pan, melt the butter on medium heat.  Add the onion and saute until softened, about 5 minutes.  Add the vinegar, ketchup, sugar, Worcestershire sauce, and Tabasco.  Bring to a boil and simmer for 15 to 20 minutes.  Remove from heat and allow to cool.  Transfer to the fridge for storage.