Vinegar-based barbecue sauce is a staple of northeastern South Carolina (the Sandhills region around Florence, Sumter and Marion), and it's what people across the country typically call North Carolina style sauce. Unlike a typical barbecue sauce, which is a balancing act of sweet and tart, most people make this stuff all about the vinegar.
It's quite thin, which is great for pulled pork and pulled chicken, but is kind of wasted on a rack of ribs.
It's easy to make. Just mix the ingredients above in a glass bottle or a squeeze bottle. Then let it sit for at least a day for the flavor to infuse.
Add the sugar if you want some sweetness added to your sauce. But remember you've got to keep it in the fridge if you add sugar.
If you like it with a hot sting, add more pepper or cayenne pepper to the mix.