Leftover mashed potatoes dry out if you reheat them uncovered or too fast. The food-safety rule is still the same as for other Thanksgiving leftovers: they should have been refrigerated within 2 hours and used within 3 to 4 days, and they need to reach 165°F in the center when you warm them, according to USDA leftover guidance. A little milk, cream, or broth, plus a lid, brings the texture back. This is a reheating method, not a recipe page; for potato cakes and other new meals, see what to do with leftover mashed potatoes.
Oven method
Heat the oven to about 325°F to 350°F. Spoon the leftover potatoes into a shallow baking dish, break up any cold clumps, and stir in a splash of milk or broth. Cover the dish tightly so the steam can loosen the mash. Reheat until the center reaches 165°F; the time depends on how much you have and how deep the dish is, so use a thermometer rather than a fixed number of minutes. Stir once halfway through if the dish is large. An oven thermometer helps if your oven runs hot or cold.
Stovetop method
For smaller amounts, a saucepan is often faster. Add a splash of liquid, set the heat to low or medium-low, and stir as the potatoes loosen. Do not walk away; leftover mash can scorch on the bottom. When the mixture is steaming and a thermometer in the center reads 165°F, it is ready. If the potatoes seem gluey, you added too much liquid or overworked them; a short rest off the heat can help, but do not leave them in the danger zone.
Microwave method
Use a microwave-safe bowl, add a little liquid, and cover the potatoes, venting the lid or wrap so steam can escape. USDA leftover advice for microwaving is to cover the food, rotate or stir it, and check the temperature in more than one spot because microwaves heat unevenly. Let the potatoes stand for a minute and confirm 165°F before serving. If you only needed part of a large container, return the rest to the refrigerator promptly. For turkey on the same plate, see how to reheat leftover turkey. Storage basics are in how to store Thanksgiving leftovers and how long leftovers last.
Do not reheat mashed potatoes that sat out more than 2 hours, or more than 1 hour above 90°F. If you have more than you will eat in 3 to 4 days, check whether leftover sides freeze well before you count on the freezer. More leftover ideas live in the Thanksgiving leftovers guide.
Helpful kitchen tools
- Pyrex Deep 9×13-Inch Glass Baking Dish with Lid — A lidded glass dish is ideal for oven reheating and for storing the potatoes afterward.
- TempPro TP19H 1-Second Digital Meat Thermometer — Check that the center of the potatoes reaches 165°F.
- OXO Good Grips 11-Inch Balloon Whisk — A whisk or sturdy spoon helps loosen leftover potatoes as they warm.
- OXO Good Grips 2-Cup and 4-Cup Glass Measuring Cup Set — Useful if you add a measured splash of milk or broth.
As an Amazon Associate I earn from qualifying purchases.
Frequently asked questions
How do I keep leftover mashed potatoes from drying out?
Reheat them covered and stir in a splash of milk, cream, or broth. Check that the center reaches 165°F.
Can I reheat mashed potatoes in the microwave?
Yes. Cover and stir them, then check the temperature in several places. Microwaves can leave cold spots.
How long are leftover mashed potatoes good?
Use refrigerated leftovers within 3 to 4 days, and only reheat potatoes that were packed and chilled on time.