Hot Pepper Vinegar is always passed with cooked greens in the south. It's also used on vegetables and meats. You can make it very simply by replacing about a quarter of the vinegar in a bottle with hot peppers and setting aside for a week. It is very common to see these peppers in old catsup bottles or liquor bottles. Spiciness varies with peppers. The following recipe is a little more trouble, but the resulting vinegar is will worth the effort.
Hot Pepper Vinegar
Mixed hot peppers, about 1 pound
Pack sterilized quart, or 2 pint jars with the mixed hot peppers, then add garlic clove. Mix the remaining ingredients in a nonreactive pot and cook at a low boil for about 30 minutes, covered.
Pour the boiling liquid over the peppers, seal the jar, and process in a boiling water bath for 10 minutes.