(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.
Prior to cooking potatoes, one way to reduce acrylamide formation is soaking them in water. According to the FDA, soaking potatoes in water for 15 to 30 minutes is sufficient to reduce the levels of acrylamide during cooking.
The soaking, Mr. Nasr said, is the secret to the crisp texture of the fries. It draws out the starch, making them more rigid and less likely to stick together.
A: You can store peeled potatoes in water in the refrigerator for about 24 hours. 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.
If you're prepping with smaller pieces, don't soak for more than 12 hours. This trick is handy, but it'll only work for about 24 hours — so don't prep too far in advance. After too long they'll start to take on water and may lose their structure when you go to cook them.
Once the potatoes have soaked, rinse and drain them. Then — also very important — use a towel to pat them down until they are nice and dry before moving onto the next step. 3. Coat with cornstarch: Another next key to crispy potatoes?
Once it's time to cook with the potatoes, drain and rinse again with cold water. Washing the potatoes twice with water will remove excess starch, which will help them to get extra crispy when roasted or fried.
As soon as you peel the potatoes, you'll want to place them into a bowl of water so they're fully submerged, and then store the bowl of potatoes and water in the refrigerator. The water will seal off the potatoes from the air, so the chemical reaction can't occur. Pretty smart.
You Don't Season the Water
As with pasta water, there's a reason to liberally salt the water in which the potatoes will cook: As the starches in potatoes warm up, they open up and absorb water (and salt if you season the water). When they're finished cooking, the cells close off.
Why use salt water for soaking potatoes? There's moisture naturally found in potatoes, and moisture is drawn to higher concentrations of salt. (This is a process called osmosis.) So, if you put the potatoes in a salt water bath, that will help draw out some of their moisture, resulting in crispier fries.
Don't fry fresh-cut potatoes
Soaking peeled, washed, and cut fries in cold water overnight removes excess potato starch, which prevents fries from sticking together and helps achieve maximum crispness.
Potatoes will be firmer and crispier if you soak them in salt water before frying or cooking. Although it may seem like an extra step, this process will help you prepare the potatoes in advance.
Soaking raw potato slices in water for 15-30 minutes before frying or roasting helps reduce acrylamide formation during cooking. (Soaked potatoes should be drained and blotted dry before cooking to prevent splattering or fires.) Storing potatoes in the refrigerator can result in increased acrylamide during cooking.
If you need more time, potatoes can be stored in water in the refrigerator for up to 24 hours. Before you're ready to cook, check to see if there is starch at the bottom of your container. If there is, give the potatoes a quick rinse in cold tap water. Then cook as directed in your recipe.
Remove the potatoes from the soaking water, place them in a towel and squeeze out as much moisture as possible. Allow the water to rest for about 30 minutes so the starch settles. Pour the water out of the bowl, leaving the starch at the bottom of the bowl. Combine the starch and potatoes just before cooking.
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.
Do you need to soak potatoes before making mashed potatoes? No. You don't need to soak potatoes before making them into mashed potatoes.
The boiling point
So your spuds are ready to hit the pot. The most important part here is that you use cold water instead of boiled – if you boil the water first, the outside will cook faster than the inside resulting in an uneven texture.
If you want to get ahead, why not boil them in advance, then toss in a little oil and store in the fridge until you're ready to roast them. There's no need to bring them back up to room temperature, just toss them into hot fat straight from the fridge.
If you do – just soak them for 5 minutes and rinse. Doing so is a science thing – soaking cut potatoes removes excess potato starch. This means fluffy mashed potatoes (and not gluey!)
After scrubbing and dicing potatoes, rinse under cold water. Soak diced potatoes in a bowl of cold water for at least 1 hour.