What Does Soaking Potatoes In Salt Water Do? (Best Fries)


One of the tastiest ways to serve potatoes is crispy fries. Many recipes for fries suggest that you soak the peeled, sliced potatoes in salt water. What does soaking potatoes in salt water do? Should you do it?

Soaking potatoes in salt water draws out water and removes excess starch, ensuring a crisper, firmer result when cooking. Soak peeled, chopped potatoes for fries in salt water for 15 minutes to 24 hours – the longer, the better. Soak unpeeled whole potatoes for baking for two to eight hours. 

Soaking potatoes in salt water seems like a time-consuming step when you’re in a hurry to get dinner made. Let’s take a look at whether this step is worthwhile and what soaking potatoes actually does.

Should You Soak Potatoes In Salt Water?

There are three instances when you should soak your potatoes:

  • when you’re making French fries
  • when you’re making baked potatoes
  • when you’re preparing potatoes ahead of time.

Why You Soak Potatoes In Salt Water

Soaking potatoes removes excess starch from the potatoes, helping them to brown, crisp, and hold together better when cooked.

While you can soak your potatoes in regular water with decent results, salt water is more effective at drawing out starch because of a process called osmosis. Through osmosis, moisture moves to higher salt concentrations, so the moisture (and starch) moves from the potatoes into the salt water.

Use cold water, not hot water, which would begin cooking the potato starch rather than releasing it.

New scientific research also suggests that soaking potatoes in salt water is healthier. Along with releasing starch and moisture, the soaking process removes a chemical called acrylamide. 

This naturally occurring chemical is usually released when the starch in potatoes cooks at high temperatures, such as in frying or baking. Acrylamide is associated with cancer, so reducing its presence in your food is a great advantage.

Why You Soak Potatoes When Making Fries

Do you often end up making limp, oily fries? You probably didn’t soak them in salt water.

The ideal fries have a crunch on the golden-brown exterior and a fluffy, soft interior. Soaking the potatoes in salt water helps to achieve this.

Your first aim in soaking the fries is to remove potato starch, which stops your fries from sticking together during frying. Potato starch is released during cooking, which is excellent for mashed potatoes but not for crunchy fries.

The other aim is to remove moisture. Removing moisture leaves the fries drier, hence more rigid. In addition, when you fry potatoes, the water content of the potato gets replaced by the frying fat. If your potato contains less moisture, it will absorb less oil and end up crispy rather than soggy. Oily fries are also less flavorful.

To soak potatoes for fries, wash, peel, and cut the fries. Soak them for four to 24 hours in a bowl of salt water in the fridge (even 15 minutes is better than nothing). Make sure the water covers the potatoes entirely so that they do not discolor.

Drain – not rinse – and dry the fries completely before air-frying, deep-frying, pan-frying, or even roasting. See my guide on salting your fries for the perfect taste.

Why You Soak Potatoes When Making Baked Potatoes 

One of the secrets of making perfect baked potatoes or wedges with crisp “jackets” and pillowy insides is soaking the potatoes in salt water before baking.

This soak is called brining – just as you brine meat before grilling to ensure tenderness.

Scrub the potatoes, removing blemishes with a knife. Soak the clean potatoes in a bowl of water with kosher salt. Drain thoroughly without rinsing, dry the potatoes, and bake.

Why You Soak Potatoes To Prevent Them From Discoloration

The third instance where you can soak your potatoes is when you’re prepping potatoes in advance. Many people avoid preparing potatoes ahead of time because, like apples or pears, raw potatoes discolor or go greyish brown when exposed to air.

An enzyme in these fruits and veggies causes discoloration, a natural process that doesn’t affect the flavor or quality of the food. However, it looks unappealing and off-putting.

You can avoid discolored potatoes by stopping oxygen from reaching the potato enzyme, using a barrier to replace the peel that usually performs this function. 

Begin by scrubbing, peeling, slicing, dicing, or chopping your potatoes as usual. I answered in my post – is peeling potatoes really necessary?

To keep your peeled potatoes looking fresh, cover them completely with cold water until you want to use them. Unless you want to draw out excess starch (e.g. if you’re frying the potatoes), there is no need to use salted water.

Keep the potatoes refrigerated in a covered bowl or airtight container until you are ready to cook them – overnight is fine. Drain and dry the potatoes before cooking unless you plan to boil them.

How To Soak Potatoes In Salt Water

Soaking potatoes in salt water is a simple process. 

  • Fill a bowl with cold water and add two tablespoons of salt of your choice. (You can add a cup of salt to eight cups of water when brining whole potatoes.) 
  • Scrub, peel and chop the potatoes for fries, or keep your potatoes whole for baking.
  • Soak the potatoes for four to 24 hours in the refrigerator.
  • Drain, dry, and cook the potatoes.

Some chefs recommend a double soaking for French fries to ensure an extra-crisp texture:

  • Peel and then soak the whole potatoes in salt water for eight hours.
  • Slice the potatoes into sticks and soak for another eight hours in salt water.

How Long Should You Let Potatoes Sit In Salt Water?

The longer you soak your potatoes, the more moisture and starch are released.

For Fries

You can soak fries for up to 24 hours in the refrigerator, but avoid soaking them longer than that as they may begin reabsorbing water.

However, any soaking is better than no soaking. If you only have 10 to 30 minutes, use that time to soak the potatoes.

For Baking

Brining potatoes for baking whole or in wedges is a shorter process. You need only soak your potatoes in their potent salt mixture for two to eight hours for good results.

To Prevent Discoloration

Because your aim when soaking potatoes to keep them from discoloring is not to draw out starch or water, you won’t be using salt water. 

You can keep potatoes soaking in regular water in the refrigerator for up to 24 hours before they start absorbing water.

Should I Add Vinegar To My Salt Water?

Some foodies swear by adding a couple of teaspoons of vinegar to their potatoes’ salt water bath. This process achieves the loss of moisture and starch and adds extra flavor to the fries. Think of the British who drizzle their fries in vinegar or salt and vinegar chips.

The vinegar soak is different from the cold salt water soak. Here, you heat the water to a simmer and then add salt and vinegar. Soak your potatoes in this warm salt and vinegar bath for an hour, then bake or fry the fries.

Conclusion

Soaking potatoes in salt water helps to draw out excess starch and moisture so that you can produce crispy fries or baked potatoes. Soak peeled, chopped potatoes for up to 24 hours in salt water if you’re making fries. Baked potatoes can soak whole and unpeeled for two to eight hours before baking. It is worth taking the time to give your potatoes a salt bath as it improves texture and flavor.

Tom

Hey, I'm Tom. I set up Boss The Kitchen to start answering the thousands of questions people have while cooking. For me, the kitchen is my happy place and I hope to help other people with the knowledge I've gained along the way.

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