Combine brown sugar, soy sauce, sorghum, black bean & garlic paste, water, malt vinegar, barley miso, sesame seeds, five-spice powder and Sriracha in a small sauce pan. Bring to a boil over medium-high heat, lower heat, and simmer until sauce thickens, about 5 minutes, stirring frequently. Place into the blender and puree until smooth. Transfer to a mason jar, label and allow to cool to room temperature, then seal and refrigerate.