The key to great fried potatoes is the crisp. National allegiances aside, the best technique comes from Belgium, where they are double fried: once to cook them through and once to form a crust. By using sous vide to precook the potatoes, this recipe avoids the need for multiple go-rounds in the deep fryer but still gives you the ideal combination of soft interior and crispy exterior.

This owes to the fact that cooked potatoes give off less steam than raw potatoes, and less steam equals a crispier crust. As an additional bonus, you can cook them days ahead of time and store them in the bag until you’re ready to fry. Be sure to use a starchy potato like a russet, as waxy potatoes will get too dark before they become crisp.

Of course, these chips are a natural to serve with my Sous Vide Fish and Chips.

Chef Griffin

British-Style Chips • Sous Vide Double-Fried Potatoes

These are proper chips – thick, crispy outside, fluffy inside. They're what you get in a good British chip shop or Belgian frites stand. Make them once and you'll never go back to regular fries.

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Course: Side Dish

Ingredients Method Notes

Ingredients

1½ pounds russet potatoes peeled, halved lengthwise, and cut into wedges ½ inch thick at their widest point (each potato will yield about 12 wedges)
1 tablespoon extra-virgin olive oil
1 teaspoon chopped fresh thyme
1 teaspoon kosher salt plus more for serving
Canola or other mild vegetable oil for deep-frying

Method

Cook the Potatoes

Preheat your sous vide water bath to 87°C (188.6°F).
Place the potatoes, olive oil, thyme, and salt in a gallon-size freezer-safe ziplock bag and shake the bag to coat the potatoes evenly with the other ingredients.
Seal using the water displacement method and then press down on the bag to distribute the wedges in a single layer (or as close to a single layer as possible).
When the water reaches 87°C (188.6°F), lower the bagged potatoes into the water bath (making sure the bag is fully submerged) and cook for 1 hour.
Remove the bag from the water bath and set aside the potatoes (still in the bag) at room temperature until you’re ready to fry.

Fry the Chips

When you are ready to fry the potatoes, transfer them from the bag to a platter or tray, discarding any liquid, and thoroughly pat dry with paper towels.
Line a second platter or tray with paper towels and place near the stove. Preheat the oven to 250°F.
Pour the canola oil to a depth of about 1½ inches into a deep cast-iron skillet. The oil should come no more than one-third of the way up the side of the pan to ensure that it will not boil over the rim once the potatoes are added.
Heat the oil over medium heat until a wooden skewer or bamboo chopstick inserted into the center of the oil bubbles immediately, or the oil registers 350°F on a high-heat thermometer.
Working in batches to avoid crowding, carefully add the potatoes to the hot oil and fry, turning occasionally to prevent sticking, until golden brown and crisp, 4 to 5 minutes.
Using a slotted spatula, transfer the chips to the towel-lined platter to blot away any excess oil. Sprinkle with salt to taste, and place in the oven to keep warm.
Repeat with the remaining potatoes. Serve hot.

Notes

Sous Vide Temperature:

87°C (188.6°F) cooks the potatoes through without breaking them down too much
They’ll be tender but still hold their shape for frying

Sous Vide Time:

1 hour is ideal
Can go up to 1½ hours if needed without issue

Potato Choice:

Use russet potatoes – high starch, low moisture
Yukon Gold works but won’t get as crispy
Waxy potatoes (red, fingerling) will turn dark before crisping

Why Olive Oil and Thyme in the Bag:

Adds flavor during cooking
Oil helps prevent sticking
Thyme is optional but adds a nice herbaceous note

Frying Temperature:

350°F is the sweet spot
Too hot: Burns before crisping
Too cool: Absorbs oil and gets greasy

Do-Ahead Strategy

If you’re making the potatoes more than 2 hours in advance of frying, chill them in an ice water bath for 15 minutes and then refrigerate for up to 1 week before frying. They can be fried straight out of the fridge, adding just a minute or two to the frying time if needed to brown completely.

As with regular fries, these chips won’t stay crisp forever after frying. If you want to keep them warm for a short amount of time, they can sit for up to 30 minutes in the 250°F oven, which is a good trick to know when serving them as a side.

Why Sous Vide for Chips?

Traditional Belgian frites are double-fried: once at a lower temperature to cook them through (blanching), then again at high heat to crisp them up. This works, but requires two separate oil temperatures and careful timing.

Sous vide replaces that first fry. The potatoes cook gently and evenly in the bag, reaching the perfect tender texture without any oil. When you fry them, you’re only doing the high-heat crisp step.

Benefits:

Less oil needed – you only fry once
Less mess – no first fry to deal with
Better texture – more even cooking
Make ahead – cook days in advance, fry when ready
Consistent results – precise temperature control

The cooked potatoes also give off less steam when fried, which means they develop a better crust. It’s the same principle as the fish in the fish and chips recipe.

Pat them dry:

This is critical
Any moisture on the potatoes = steam = soggy chips
Use paper towels and really dry them off

Don’t crowd the pan:

Fry in batches
Crowding drops oil temperature
Potatoes steam instead of fry

Season immediately:

Salt the chips right when they come out of the oil
Hot oil helps the salt stick
Season to taste – don’t be shy

Keep warm properly:

Spread on a sheet pan in a single layer
Don’t pile them up or they’ll steam each other
250°F oven keeps them warm without further cooking

Classic:

With Sous Vide Fish and Chips
Malt vinegar for sprinkling
Ketchup on the side

Pub-style:

With steak and peppercorn sauce
Alongside burgers
With grilled sausages

Dressed up:

Truffle oil and Parmesan
Garlic aioli for dipping
Fresh herbs (rosemary, thyme) tossed after frying

International:

Belgian-style with mayo
Canadian poutine (add gravy and cheese curds)
Spanish patatas bravas style (with spicy tomato sauce)

Different seasonings:

Smoked paprika
Garlic powder and onion powder
Old Bay seasoning
Cajun spice blend

Herb variations:

Fresh rosemary instead of thyme
Sage for autumn flavor
Mix of herbs de Provence

Spicy chips:

Add cayenne pepper to the bag
Dust with chili powder after frying
Serve with sriracha mayo

Loaded chips:

Top with cheese sauce
Add bacon bits
Drizzle with gravy (British chip shop style)

The Science

Potatoes are mostly starch and water. When you fry raw potatoes, the outside cooks quickly while the inside is still raw. By the time the inside cooks through, the outside can be overcooked or burnt.

Sous vide solves this by cooking the potatoes through first at a precise temperature. The starch gelatinizes evenly throughout. When you fry them, you’re only developing the crust – the inside is already perfect.

The other advantage: cooked potatoes have less water content at the surface. Less water means less steam when frying, which means better crisping. The result is chips that are fluffy inside and shatteringly crisp outside.

Cutting the Potatoes

The wedge shape is traditional for British chips – they’re thicker than American fries. Here’s how to cut them:

Peel the potatoes
Cut each potato in half lengthwise
Place cut-side down and cut each half into 5-6 wedges
Each wedge should be about ½ inch thick at the widest point

Don’t cut them too thin – these aren’t skinny fries. The thickness gives you that contrast between crispy exterior and fluffy interior.

British-Style Chips • Sous Vide Double-Fried Potatoes