A frozen beverage device (10) has a container (20) and sealable cover (30) to convert a liquid (60), such as a non-alcoholic or alcoholic beverage into an at least semi-frozen slurry containing ice crystals (61). Freezing device(s) (50), which may have a range of shapes, contain refrigerant to from a thin layer of ice/ice crystals on the deformable wall(s) of the freezing device(s) (50), the ice crystals (61) being released therefrom due to agitation of the liquid (60) by shaking/rotation and/or squeezing on the container (20) and/or cover (30).