San Giacomo makes the Saba from the same cooked grape must that is used for making balsamic vinegar, but the Saba is not fermented or aged. It is reduced by 1/3 over an open fire during which the sugars caramelize and the flavor becomes more concentrated and you'll get a more syrupy consistency, which is called a miele d'uva or grape honey in Italian.
San Giacomo uses local grapes, Lambrusco and Trebbiano grape to create the product. The cooking process results in a sweet product; balsamic vinegars are often sweet and acidic.
Use Saba instead of balsamic in cooking, or pour it over ice cream, serve it as a cheese accompaniment.