A hydraulic blow molding apparatus having a container forming station with a forming head coupled to a source of liquid blow medium. The container forming station further includes a mold configured to receive a preform and has interior surfaces that define the container shape. The container forming station injects a liquid end product into the preform and expands the preform to simultaneously form and fill a container with the liquid end product. Prior to the container being removed from the container forming station and while it is still full of the liquid end product, a seal is engaged with the container.