Abstract: An expandable enclosure and a method for using it are provided for freeze forming a processed mass of meat or poultry products into a desirable and naturally occurring cut of meat. This enclosure includes a elongate housing with an opening for receiving the mass, a displaceable cover which the product mass displaces as it expands during freezing, and fastening apparatus for providing resistance to the separation of the cover from the housing so that the cover can maintain pressure on the mass to expel voids and excess moisture from the mass and to press the mass into the shape of the enclosure. The method for using the enclosure involves placing the mass in the enclosure and freezing it until the center of the mass reaches a predetermined temperature necessary to maintain cohesiveness of the mass.