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 you use sparkling drink mixes? How much Sparkling Drink Mix should I use? Can I add anything other than Sparkling Drink Mix to my bubbly water? How do I use my carbonating bottle and sparkling water maker? How do I get the right level of carbonation?