You should store peeled and cut potatoes in water for 24 hours to ensure the quality of your final product. "If you drain the potatoes and notice they are turning brown, that they've started getting soft, or if they are slimy you should discard them," says Brigman.
Peel potatoes using a vegetable peeler. It's best to leave them whole, but you can go ahead and cube or dice them if you want — just don't slice them too thin. Fill a bowl with cool water, submerge the potatoes, then cover with plastic wrap. Store in the refrigerator overnight.
Peeled potatoes left out by themselves at room temperature, on a refrigerator shelf or wrapped in foil or plastic wrap will still get dark overnight, so submerge them in a bowl of water, cover and refrigerate. Cubed peeled potatoes can sit in water overnight, but they need to be refrigerated.
No matter which way you slice (er, peel?) it. The short answer is yes. You can absolutely peel potatoes ahead of time.
Prepping the potatoes ahead of time
To save time on peeling and chopping on Thanksgiving Day (or any other day that includes 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.
If you'll be cooking the potatoes in the next few hours, you can leave them submerged in water at room temperature, Tiess says. If it will be longer than a few hours, place them in the refrigerator. Peeled, sliced, submerged, and refrigerated potatoes should be cooked within 24 hours.
The result is very fluffy mashed potatoes. (If you decide to try soaking the raw potatoes anyway, they can be soaked in water in the refrigerator for several hours without any safety concerns. Potatoes can be soaked even overnight as long as they are in the refrigerator.)
We usually recommend no more than 24 hours. You can keep the potatoes from absorbing the water by making sure the water is not salted, and is chilled (you can even add ice to the water). To keep the potatoes from turning black from oxidation, add 1 teaspoon of lemon juice or white wine vinegar to a gallon of water.
You should store peeled and cut potatoes in water for 24 hours to ensure the quality of your final product. "If you drain the potatoes and notice they are turning brown, that they've started getting soft, or if they are slimy you should discard them," says Brigman.
Soaking potatoes in water helps remove excess starch. Excess starch can inhibit the potatoes from cooking evenly as well as creating a gummy or sticky texture on the outside of your potatoes. Cold water is used because hot water would react with the starch activating it, making it harder to separate from the potatoes.
Just be sure to store peeled potatoes in water for no more than 24 hours. After that, the cool refrigerator air will convert the starches in the potatoes to sugar, causing the flavor and texture of the spuds to change. Instead, just start cooking potatoes for a mash, potato salad, or hash browns.
Leave the potatoes in salt water for 15 to 30 minutes before frying. But if needed, you can also soak them for no more than 24 hours.
Don't forget that most of the veg can be prepared the day before. Peel and trim your carrots and parsnips (keep them submerged in water overnight), peel onions and, to really save you time, don't just peel your potatoes the day before but you can parboil them, too.
"It's best to wash just before you cook, but they're probably fine to wash up to 24 hours before cooking," says Fields-White. (Think Thanksgiving mashed potatoes for a crowd, where you need to start prep early; Fields-White says it's OK to wash in advance and then refrigerate.)
Raw potatoes that have been cut should be stored in a bowl of cold water and refrigerated. They'll be good for the next 24 hours. And finally, cooked potatoes will last three to four days in the fridge, as is the case with most leftovers.
Soak it in salted water after peeling and cutting it into equal lengths. After 30 minutes, drain and replace the water. Then, in freshwater, boil it for 15 minutes.
Give them a cold water bath: Once your potatoes are chopped, toss them into a large bowl. Then cover the potatoes completely with cold water and let them soak for at least 30 minutes (or up to overnight). This will help to rinse off the excess starch and help the potatoes crisp up beautifully in the oven.
Excess starch can make potatoes gummy or gluey.
Rinsing potatoes with cold water prior to boiling helps remove excess starch. Rinsing with hot water immediately after boiling can remove even more starch. Cutting potatoes before boiling does remove excess starch.
Soaking potatoes allows you to get rid of most of the starch, remove nitrates, and make the product less nutritious and more useful.
Rinsing potatoes helps remove excess starch, so it is recommended to rinse the potatoes before cooking. To ensure even more starch is out of the way, it's recommended that they even be quickly rinsed after boiling. We recommend using hot water for rinsing after boiling and cold water prior to boiling.
Doing so is a science thing – soaking cut potatoes removes excess potato starch. This means fluffy mashed potatoes (and not gluey!)
Make-ahead mashed potatoes are a great option for the holidays. You can do nearly everything — boil, peel, and mash; stir in milk and salt — up to two days ahead. Before serving, reheat. Adding butter at the last minute makes them taste freshly mashed.