Published September 12, 2018 15:02 How do you use Fruit Drops flavors? Add approximately 1/2 teaspoon of flavor drops to one liter of sparkling or still water. Your delicious bubbly beverage will stay fresh for six weeks after opening (not that you'll be able to wait that long to drink it!). Related articles How do I use my carbonating bottle and sparkling water maker? How much Sparkling Drink Mix should I use? My sparkling water is not fizzy enough. Help!