Champagne vinegar is made from sediments and small amounts of champagne that are collected during the production process. Collected sediments combined with certain bacteria are stored in aerated tanks, where they convert to vinegar. Some manufacturers age the vinegar in oak barrels for up to a year before bottling.
Champagne vinegar can also be made at home by allowing champagne to sit in open, wide-mouthed jars for several weeks. Once the champagne turns to vinegar, it keeps for up to six months in covered jars or bottles. Champagne vinegar, which is less pungent than regular vinegar, can be used in sauces, salad dressings and marinades.