A method and apparatus for opening and closing a cartridge holder of a beverage forming machine. The cartridge holder may have an opening arranged to receive and hold a cartridge with the cartridge holder. The opening may be adjustable in size and/or shape to allow the cartridge holder to receive and engage with cartridges of different size and/or shape. The cartridge holder may include one or more movable portions that are adjustable in position to effectively adjust a size and/or shape of the opening.