1 Fruit cake will keep for an additional 6 months in the refrigerator, covered with foil or plastic wrap or placed in a plastic bag. 2  To freeze, wrap fruit cake tightly with aluminum foil or plastic freezer wrap, or place in heavy-duty freezer bag.RUIT CAKE — FRESHLY BAKED. 1  Fruit cake may be kept at room temperature for up to one month; cover with foil or plastic wrap or place in plastic bag to prevent drying out.