Fill a clean pint jar with whole raspberries, pressing down slightly to fit in jar snugly. Add enough vinegar to cover raspberries. Cover mixture and let macerate at room temperature for 1 week. Set a strainer over a medium bowl; line with a double layer of cheesecloth. Pour vinegar mixture through strainer. Gather corners of cheesecloth and twist to release juices just until thicker juices begin to strain from cheesecloth. Discard cheesecloth with solids. Pour vinegar into a clean 8-ounce bottle or jar. Cover; chill up to 6 months.