Make-ahead mashed potatoes and how to reheat them
Short answer: make them up to 2 days ahead and keep them in the fridge. On Thursday, reheat them in a slow cooker on low for 1 to 4 hours, or covered in a 350 °F oven for 30 to 60 minutes, depending on the recipe. The slow cooker is the one that keeps the oven free for the turkey and the casseroles.
Mashed potatoes are the side most people move to a slow cooker or the stovetop, because they need no browning. This page compares what three published recipes say, so you can pick a method by how much oven you have left. Whichever you choose, heat them until hot all the way through.
What three recipes say
| Recipe | Potatoes | Makes | Oven, 350 °F | Slow cooker, low |
|---|---|---|---|---|
| Food Network Kitchen | 4 lb | About 9 cups; a 13 by 9 inch dish | 20 min covered, stir, 20 to 25 min more | Not covered |
| Frugal Hausfrau | 5 lb | 10 to 12 servings | About 1 hour covered | 1 to 2 hours, stir halfway |
| MomAdvice | 5 lb | Serves 15 | 30 to 40 min | 2 to 4 hours |
The recipes disagree. The same 5 lb batch is "10 to 12 servings" in one and "serves 15" in the other, and the oven time runs from 30 minutes to an hour. Part of that is probably dish depth, but no source sorts it out. Treat the times as ranges and check the middle of the dish. The Food Network recipe stirs the last 1/2 cup of cream in before reheating, so its potatoes start loose.
How far ahead
Food Network Kitchen says to refrigerate its potatoes "up to 2 days", or freeze them up to 3 months, and to cool them to room temperature before they go into an airtight container. Frugal Hausfrau makes hers "a day ahead". For a Thursday dinner, Tuesday evening is the earliest. Frozen potatoes go to the fridge first: Food Network says to thaw them completely, then reheat as usual without adding cream, and MomAdvice moves them to the fridge "1-2 days before". The make-ahead calendar shows where this fits among the other dishes.
Which method frees the oven
- Slow cooker. The potatoes use no oven slot at all. MomAdvice sprays the cooker, adds the thawed potatoes and brushes the top with butter. Frugal Hausfrau covers them and says they can be held warm about an hour longer, though not ideally. The range is 1 to 4 hours, so start early and treat the shorter times as a minimum.
- Oven. 350 °F is the temperature of stuffing and most casseroles, so the dish can share a rack with them. Cover it with foil and stir once. Food Network warns that potatoes heated "too fast and too hot" can turn gluey, which is its case against the microwave.
- Stovetop. None of the three pages covers it for a cold, set batch. Frugal Hausfrau does heat doubled batches on the stovetop before moving them to the slow cooker, which saves slow cooker time.
Leftover rules
University of Illinois Extension says leftover food "should be refrigerated or frozen within two hours of serving", should be used within 3 to 4 days when refrigerated, and should be reheated "to a minimum of 165 F". That covers the potatoes you serve and put away. Its page does not mention slow cookers. The recipes judge by "hot" or "steamy", so a thermometer reading 165 °F in the middle of the dish is a firmer check. Sources, all opened on October 15, 2026: Food Network Kitchen, Frugal Hausfrau, MomAdvice and Illinois Extension.
On the day
Start the slow cooker in the morning, and the turkey keeps the oven to itself until it comes out to rest. If you use the oven, the potatoes join the sides at 350 °F once the turkey is out. Add them to the planner as a stovetop dish for the slow cooker, or as a 350 °F dish for the oven, and it places every other start time around them. The 350 °F times for the rest of the sides are on reheating Thanksgiving sides while the turkey rests.
Related
- Everything else on the menu: Thanksgiving dinner with one oven.
- Turkey still frozen? Cook a frozen turkey without thawing gives the longer start time.
- The temperatures the other sides want: side dish oven temperature chart.