The carbonation device includes a cap system selectively mounted to the mouth of a liquid container. The cap system includes a cap, a rotatable control ring coaxial with and selectively attached to the cap, a reaction vessel selectively attached to the bottom of the cap, and an elongate distribution tube selectively mounted to the cap. The reaction vessel is filled with a preselected amount of carbonating material such that when the control ring is rotated in one position, water may be introduced into the vessel to initiate the carbonation reaction. In another position, the carbonating gas flows into the liquid via the distribution tube. Other rotated positions permit locking and unlocking of the control ring. The carbonation device also includes a drop-in configuration that serves as a self-contained carbonation distribution vessel.