Champagne vinegar isn’t actually made from champagne, though all the marketing would invite you to believe that it is, with words such as sparkling, crisp, clear, etc.
Rather, it is a mild-tasting, slightly dry white wine vinegar that happens to be made from the same grapes as champagne is — Chardonnay or Pinot Noir grapes. Champagne vinegar can only be produced in the Champagne area of France.
Still, many people say it has a nicer taste than regular white wine vinegar, and is good with citrusy salads.
A light white wine vinegar