A capsule for storing a fixed amount of syrup. The capsule includes a housing to store the fixed amount of syrup and is shaped to sit on an opening of a bottle of liquid. The capsule also includes a release mechanism to release the syrup in a controlled manner into the bottle. The invention includes a method for releasing syrup from a capsule into a bottle of carbonated water. The method includes the capsule being placed on a rim of the bottle and the capsule receiving a downward force.