Keep Mashed Potatoes Warm
This traditional way to keep potatoes warm still works just as well as it did 50 years ago. Give it a try!
To keep mashed potatoes warm without drying them out, place them in a water bath, or bain-marie. Set the dish or pan of potatoes in a larger, fairly shallow pan of hot, simmering water; cover loosely with plastic wrap and stir occasionally. The potatoes will keep great this way for an hour or more.