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.
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.
A: 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).
The potato in the salt water shrinks because water moves from the potato into the more concentrated salt water. In contrast, water moves from the less concentrated distilled water into the potato causing it to expand.
Should potatoes be soaked before roasting? Yes! Soak the potatoes in cold water to remove the excess starch from the outside of the potato.
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.
The best way to store peeled and cut potatoes is in a pan of salted water in the refrigerator. They can be kept overnight without a problem and even longer if needed. The cold water and salt keep the potatoes from turning brown.
Add enough cold water to cover the tops of the potatoes. Add ½ to 1 teaspoon salt to the water. Turn the burner on high and bring water to boiling. Reduce the heat to medium-low or low.
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.
Potatoes specifically intended for salt potatoes can be purchased by the bag along with packages of salt. As the potatoes cook, the salty water forms a crust on the skin, and the higher boiling temperature allows the starch in the potato to cook more completely, giving a creamier texture.
(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.)
Can you peel raw potatoes and leave them in water overnight? A: You can store peeled potatoes in water in the refrigerator for about 24 hours.
Doing so is a science thing – soaking cut potatoes removes excess potato starch. This means fluffy mashed potatoes (and not gluey!)
A: Chefs started doing this years ago to allow the salt to absorb or draw out the moisture of the potato while baking, which results in a dry, fluffy potato. They used to do something similar with prime rib, sometimes baking it over rock salt.
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.
They just won't stand up to an overnight soak, so don't do it. The larger the potato pieces, the longer they'll last in water. 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.
Leaching method: Peel and dice potatoes. Place in a large pot of warm tap water and soak for 2 to 4 hours. Drain and set aside.
Well, potatoes don't pull salt out of anything. They do absorb water, though—and if that water happens to be salty, they'll absorb salty water. But they're not absorbing salt in particular.
Salt is the key here. Water will move from an area of less salt to more salt (more water to less water), and so when the potato is placed in the saltwater, all the water that is inside the potato (yes, plants have a lot of water inside of them, that's what gives a plant it's structure) moves out by osmosis.
The boiling point
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. Cubed spuds will take around 15 minutes where larger chunks or whole new potatoes will be 20-25 minutes.
Vinegar causes the potatoes to form a thin crust that further helps in retaining their shape. Vinegar increases the acid pH levels of water which further helps the potato just like when you add a little salt to the water while boiling eggs.
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. The cooks fry them twice, first blanching them until slightly limp in peanut oil heated to 325 degrees, and again in 375-degree oil to crisp and brown them.
Boiling the potatoes in a salt and vinegar bath allows them to soak up all of that briny flavor before you dry them off and crisp them up in the oven. The result is a soft-in-the-center, crispy-on-the-outside potato that's loaded with flavor.
First let's talk about why cut potatoes need to be immersed in water to begin with. The reason is to prevent the potatoes exposure to air, which causes dehydration, oxidation, and discoloration. Immersing cut potatoes will also help rinse off excess starch.
Potatoes can be peeled prepped and cut into water up to 2 days before boiling for mash.