- 1 cup balsamic vinegar (supermarket quality is fine)
- Pour the vinegar into a small, heavy, nonreactive saucepan, preferably one with a pouring spout. Bring to a boil over high heat. Reduce the heat and cook at a moderate boil until thickened and reduced to about 1/3 cup, about 12 minutes. Cool in the pot, and then pour into a small glass jar and store at room temperature. Lasts indefinitely.