A beverage forming system and method in which a wall member mounted to a frame of the system defines a first portion of a chamber, and a cartridge holder movably mounted relative to the frame and the wall member defines a second portion of the chamber. The cartridge holder may have an opening to receive a cartridge and be arranged to hold and move a cartridge between an open position and a closed position. A cover, which may be moveable relative to the wall member and/or the cartridge holder, may be arranged to cover the opening of the cartridge holder with the cartridge holder in the closed position. Thus, with the cartridge holder in the closed position and the cover covering the opening, the cartridge holder, the wall member and the cover define the chamber in a closed state in which a cartridge held by the cartridge holder is enclosed.