In a clean ice tray, drop a few blueberries and/or raspberries in each cavity. Top with water. Freeze until solid.
Remove from tray and place in freezer-safe zip-lock bag in freezer until needed for mocktails.
Mocktails
To a champagne flute, add the white balsamic vinegar. Top with sparkling water, filling about 3/4 of the glass. Add 6-8 pieces of plain ice and berry ice. Serve immediately.