A mixing chamber for use in a beverage carbonation system is provided. In one embodiment, the mixing chamber includes a housing, an agitator, a motor assembly and a rigid plate. A housing of the agitator and a housing of the motor assembly can each include a set of magnetics disposed therein and magnetically coupled so as to provide magnetic coupling between the motor assembly and the agitator. The mixing chamber is configured to receive a gas, such as carbon dioxide, and a liquid, such as water, to form a carbonated fluid. The carbonated fluid can be dispensed from the beverage carbonation system as a beverage.