Place the rosemary leaves in the center of a 6-inch square of cheesecloth. Bring up the ends and tie tightly with kitchen twine. Set aside.
Combine the vinegar, garlic, and sugar in a small heavy saucepan. Bring to a boil and cook for 10 minutes. Remove from the heat. Add the rosemary sachet, and let steep no longer than 5 minutes. Once the rosemary is removed, let the vinegar cool completely.
Strain the cooled vinegar through a fine mesh sieve. Place the 2 cloves of the garlic and the rosemary sprig in a sterilized 1-cup glass jar or decorative container. Add the vinegar and seal with sterilized, self sealing lids. Use as needed.
Yield: Makes 1 cup
Note: Depending upon how long you hold the vinegar after bottling, the solids inside will start to break down and/or discolor.