Quick answer: Keep mashed potatoes warm in a covered dish on a food warming mat or warming tray, in a slow cooker on "warm," or in a covered pot over a pan of simmering water. Stir in a splash of warm milk or a pat of butter every 30–45 minutes so they stay creamy, and keep them at 140°F or above.
5 ways to keep mashed potatoes warm
| Method | How long | Best for |
|---|---|---|
| Covered dish on a food warming mat | Through the whole meal | Serving at the table |
| Slow cooker on "warm" | 2–4 hours | Making them ahead |
| Double boiler (heat-safe bowl over simmering water) | 1–2 hours | Stovetop holding |
| Covered dish in a low oven (about 200°F) | Up to 1 hour | When the oven is free |
| Chafing dish | 2–4 hours | Buffets and big crowds |
How to stop them drying out
- Keep them covered. A lid or foil traps steam.
- Add fat and liquid as they sit. Warm milk, cream or butter stirred in keeps them smooth.
- Use a deep dish. Less surface area means less crust.
- Stir occasionally so the bottom doesn't scorch and the heat stays even.
Can you make mashed potatoes ahead?
Yes. Make them up to two days ahead, refrigerate, then reheat on the stove or in the oven with extra milk and butter until hot. Once they're hot, move them to a warmer to hold. Warmers keep food hot; they aren't designed to reheat it from cold.
Frequently asked questions
How long can mashed potatoes sit out?
No more than 2 hours at room temperature. On a warmer at 140°F or above, they can be held for several hours.
Can I keep mashed potatoes warm in a slow cooker?
Yes. Grease the insert, add hot mashed potatoes, set it to "warm" and stir every 30–45 minutes with a little warm milk.