Easy Casserole Dish Method: Freeze your mashed potatoes right in the dish. You can remove the potatoes and wrap really well in plastic wrap and foil until ready to use. Then, unwrap, defrost, and reheat. Individual Servings: Use a large ice cream scoop and freeze on a rimmed baking sheet pan in 1-cup portions. Then once frozen, put in a resealable plastic bag freezer-safe or airtight container and use them within 2 months. Creative Portion Ideas: Alternatively, you can freeze leftover potatoes in silicone molds or slice a pan of leftovers into individual portions and freeze them, then break the frozen mashed potato cubes into a container or freezer bag. Vacuum Packing: Home Vacuum sealers are also great kitchen tools, that keep freezer burn and ice crystals away from frozen foods. It is not a very time-consuming method and saves you money in the long run. They preserve the flavor and taste of frozen sweet potatoes, meats and so much more.