A: Yes, you will lose nutrients if you soak potatoes in water; the longer they soak, the more you lose. Potatoes are a good source of potassium, vitamin C and some B vitamins, and a portion of these water-soluble nutrients will leach into the water.
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 presence of starch makes the texture of the potatoes soft and mushy, but at the same time it also adds on the carbohydrate content of potatoes. So, if you are planning to cut down on calories and enjoy your favourite potatoes without feeling guilty, then removing the starch content is the best thing to go for.
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.
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.
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.
The best potatoes for French fries are soaked in a sugar solution before frying. The sugar solution has something to do with the carbohydrates and prevents the potatoes from soaking up a lot of grease, so they get crunchy.
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.
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.
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.
According to Julie Upton, MS, RD, and member of our Medical Expert Board, the healthiest way to eat your potatoes is to leave the skin on and bake them. "The healthiest way to eat a potato is baking it with the skin on," says Upton. "Baked potatoes add no additional calories like frying or roasting with oil."
Cold cooked potatoes are great for your gut health because they contain resistant starch which help feed the beneficial bacteria. Once cooled the sugars in the potatoes become resistant to human digestion, but they travel through the gut to feed the microbes.
Potato starch can improve digestive and colon health
As resistant starch ferments, it feeds the healthy bacteria inside the colon as it converts into short-chain fatty acids. Butyrate is a short-chain fatty acid that forms during this process — it plays an important part in the cells of the colon.
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.
Cold Water Soak
A quick rinse under cold water can wash away much of the surface starch. More starch is removed from a cut potato than a whole peeled potato, because a greater surface area is exposed on cut potatoes. Soak them in cold water for as long as a few hours to remove more starch than by rinsing alone.
Certain high-potassium foods, such as potatoes, can be soaked in water to reduce their potassium content for people on the kidney diet. For years, renal dietitians have instructed patients on low-potassium diets to cut up and leach or soak potatoes to reduce the potassium load.
Potassium in Potatoes
One medium potato delivers 610 mg of potassium, or roughly 17% of the daily value (DV). That's about 40% more potassium than you'll find in a banana, which only contains 422 mg, or 9% DV.
Baked potatoes with the skin still on are the best option, as much of a potato's potassium is in the skin. One medium baked potato with skin contains 941 mg of potassium.
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.
Rinsing or soaking cut raw potatoes helps to wash away a very small amount of amylose. But the potatoes must be cut into one-inch pieces to expose enough surface area to wash away any significant amount of amylose.
Doing so is a science thing – soaking cut potatoes removes excess potato starch. This means fluffy mashed potatoes (and not gluey!)
To keep them from turning brown or becoming mushy when cooked, add some white vinegar (1 Tbsp. per 2 cups water) before submerging the potatoes. You can also toss cut potatoes with a mixture of vitamin C and water to keep them white without flavoring them.
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.
French Fries
Ingredients: Potatoes, Vegetable Oil (canola Oil, Corn Oil, Soybean Oil, Hydrogenated Soybean Oil, Natural Beef Flavor [wheat And Milk Derivatives]*), Dextrose, Sodium Acid Pyrophosphate (maintain Color), Salt.