A method for making surgical slush; the method comprising: obtaining a closed slush container having contents of liquid saline and an air gap; the closed slush container having a set of interior walls including a bottom end surface of the closed slush container and a lid end surface of the closed slush container that are smooth and hydrophobic to resist adherence of ice crystals to the set of interior walls; inserting the closed slush container into a carriage assembly within a cooling compartment with ambient air; and moving the closed slush container to impart accelerations on the contents of the closed slush container so the contents move in a complex set of motions rather than constant rotation around a longitudinal centerline of the slush container as at least a portion an exterior of the closed slush container is exposed to ambient air cooled below a freezing temperature for the liquid saline contained in the closed slush container as the liquid saline is converted into surgical slush with a mixture of liquid saline and ice crystals, wherein the complex set of motions is at least partially accomplished by movements of the carriage assembly within the cooling compartment, wherein the closed slush container is subject to: a series of repeated cycles of complex movements and within a cycle of complex movements, the closed slush container is rotated in a first rotational direction and a second rotational direction; and the cycle of complex movements includes asymmetric rotation reversals to cause a momentum of the contents of the closed slush container to rotate the contents of the closed slush container more in a one rotational direction selected from the first rotational direction and the second rotational direction than in a rotational direction opposite the one rotational direction so that the contents of the closed slush container rotates from a first starting point before one cycle of complex movements to a second starting point before a next cycle of complex movements. obtaining a closed slush container having contents of liquid saline and an air gap; the closed slush container having a set of interior walls including a bottom end surface of the closed slush container and a lid end surface of the closed slush container that are smooth and hydrophobic to resist adherence of ice crystals to the set of interior walls; inserting the closed slush container into a carriage assembly within a cooling compartment with ambient air; and moving the closed slush container to impart accelerations on the contents of the closed slush container so the contents move in a complex set of motions rather than constant rotation around a longitudinal centerline of the slush container as at least a portion an exterior of the closed slush container is exposed to ambient air cooled below a freezing temperature for the liquid saline contained in the closed slush container as the liquid saline is converted into surgical slush with a mixture of liquid saline and ice crystals, wherein the complex set of motions is at least partially accomplished by movements of the carriage assembly within the cooling compartment, wherein the closed slush container is subject to: a series of repeated cycles of complex movements and within a cycle of complex movements, the closed slush container is rotated in a first rotational direction and a second rotational direction; and the cycle of complex movements includes asymmetric rotation reversals to cause a momentum of the contents of the closed slush container to rotate the contents of the closed slush container more in a one rotational direction selected from the first rotational direction and the second rotational direction than in a rotational direction opposite the one rotational direction so that the contents of the closed slush container rotates from a first starting point before one cycle of complex movements to a second starting point before a next cycle of complex movements. a series of repeated cycles of complex movements and within a cycle of complex movements, the closed slush container is rotated in a first rotational direction and a second rotational direction; and the cycle of complex movements includes asymmetric rotation reversals to cause a momentum of the contents of the closed slush container to rotate the contents of the closed slush container more in a one rotational direction selected from the first rotational direction and the second rotational direction than in a rotational direction opposite the one rotational direction so that the contents of the closed slush container rotates from a first starting point before one cycle of complex movements to a second starting point before a next cycle of complex movements.