Prep. Mix the wet ingredients together in a bowl.
Crush bouillon cube, crush it with a spoon in a bowl and add it to the bowl. Crush the rosemary leaves and celery seed and add it to the bowl. Add the rest of the dry ingredients to the bowl and mix thoroughly.
Cook. Simmer for 10 minutes to pasteurize it.
Serve. Pour into a clean jar and use as you would any BBQ sauce. Store remaining sauce in the fridge. Leftovers will keep in the fridge for months.