What advantage does the Keykeg provide in beer storage and dispensing?

The Keykeg system is designed with a unique feature where the gas used for pushing the beer remains isolated from direct contact with the liquid itself. This is achieved through a double-walled structure: the inner barrier holds the beer, while the outer layer contains the gas. This design allows for effective dispensing of the beer while ensuring that the beer's integrity and flavor are maintained, as there is no risk of gas interacting with the liquid. This distinction is crucial for preserving the quality of the beer, preventing oxidation, and avoiding contamination.

Other choices may highlight some relevant elements of beer storage and dispensing but do not capture this pivotal advantage that directly relates to flavor preservation and stability in the Keykeg system.