SodaStream Blackberry Bubly Drops are meant to be a fun addition to just your ordinary drinking water. These drops have an unsweetened natural flavor essence with a touch of blackberry. Create your own sparkling and bubbly water in the comfort of your home with SodaStream. Bubly contains no calories, no caffeine, and no sweeteners. To use, simply add about 3/4 teaspoon of bubly drops to a 1 liter Sodastream bottle of sparkling water. Adjust to taste. Refrigerate after opening. Always fizz before adding any flavor. Comes in a ready to use 40 ml. bottle.