When you’re planning a major feast, you want to get as much prepared in advance as you can. (So see all the Thanksgiving recipes you can make ahead.) If you’re making mashed potatoes, you can peel the spuds and keep them submerged in a bowl of water in the fridge, whole or cut up, for hours—even overnight—before boiling.
Will Owen has kept peeled potatoes refrigerated in water-filled, zipper-lock bags for several days with no ill effects. Karl S says there’s a better way that avoids the whole issue: “[D]on’t chop, don’t peel. Steam them whole. Pop them into a potato ricer with the peel, and the peel stays in the hopper. This way you get way less moisture in the potato, and that makes for better mashed potatoes.”
Others take it a step further and mash their potatoes ahead of time, up to the day before, reheating them in the oven or microwave. danhole, who adds a bit of extra butter and reheats in the microwave, says hers come out nice and fluffy, and taste even better than freshly mashed. valerie makes hers supercreamy (with butter, half-and-half, and sour cream), and says they reheat beautifully in the oven. Diane in Bexley’s secret is to add cream cheese (around six ounces per five pounds of potatoes).
Here’s what not to do: Don’t boil your potatoes ahead and wait to mash them, even for half an hour, and don’t hold mashed potatoes in a slow cooker. Both result in a mash so gluey even a paste-eating kindergartener wouldn’t touch them.
Board Link: Prepping Mashed Potatoes