In a medium saucepan, mix all ingredients, except for butter and siracha, together over a medium low heat, stirring occasionally until sauce is well blended and hot. Remove from heat. Stir in butter. Let cool, 10-15 minutes.
In a blender, with a heat proof jar, blend sauce in batches. For safety, cover lid with a towel. Check seasoning, adding more salt or hot sauce if desired.
Brush warm sauce over skewers, chicken, pork or ribs.