Add vinegar to a saucepan and bring to a simmer over medium heat, about 8 mins. Once simmering lower heat down to low. Stirring occasionaly, cook until glaze is reduced by half and coats the back of a spoon.*Once simmering it will take approximately 20 mins for a thiner glaze and 40-50 mins for an extra thick glaze.
Let cool to room temperature and store in the refrigerator in an airtight container.