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Why won’t my roast potatoes go crispy?

Crispy roast potatoes are one of the best parts of a Sunday roast or holiday meal. When properly cooked, they should have a delicious golden brown and crunchy exterior with a fluffy interior. However, it can be frustrating when your roast potatoes turn out soggy instead of crispy. There are several possible reasons why your roast potatoes may not be getting crispy.

Using the Wrong Potato Variety

The variety of potato you choose can make a big difference in the crispiness of your final roast potatoes. Waxy potato varieties like red potatoes and new potatoes have a higher moisture content and more starch. This means they are less likely to get super crisp when roasted.

For best results, choose a starchy, floury potato variety such as Russet or Yukon Gold. These potatoes have a lower moisture content and will roast up crispier. They also have more starch which converts to sugars when cooked, enhancing browning and caramelization.

Not Parboiling the Potatoes

Parboiling or partially cooking the potatoes before roasting is essential for crispy roast potatoes. Here’s why:

  • It cooks the insides of the potato partially so they don’t remain raw when roasted.
  • It helps drive moisture out of the potatoes.
  • It ruptures the cell walls of the potato, allowing the insides to fluff up during roasting.

Skip this step and you’ll likely end up with a potato that is crispy on the outside but still dense and hard on the inside – not ideal!

Not Roughing Up the Potato Surface

After parboiling, you need to rough up the surface of the potatoes before roasting. This creates more edges and nooks for the potato to get crispy and browned.

To rough up the surface, toss the hot parboiled potatoes in a bowl with the back of a spoon or ladle. The agitation will break up the surface and create the ideal crispy texture.

Not Using Enough Oil

Roast potatoes need plenty of oil to crisp up properly in the oven. The hot oil allows the surface of the potatoes to fry to a crispy golden finish.

Use at least 1/4 cup of oil per 1-2 lbs of potatoes. Toss the potatoes in oil after parboiling so they are fully coated. Use an oil with a high smoke point like canola, vegetable, peanut or sunflower oil.

Overcrowding the Baking Sheet

It’s important not to overcrowd your baking sheet when roasting potatoes. Having the potatoes too close together prevents hot air from circulating properly in the oven.

Give the potatoes plenty of space on a rimmed baking sheet – aim for a single layer with at least 1 inch between potatoes.

Not Roasting at a High Enough Temperature

Crispy roast potatoes require high heat. Try setting your oven to 425°F or higher when roasting. Lower temperatures may cook the potatoes but won’t draw out enough moisture or create the crunchy exterior.

Not Roasting Long Enough

In addition to high heat, crispy roast potatoes need ample time in the oven. Depending on the size, potatoes may require 45-60 minutes in the hot oven to fully crisp up.

Resist the urge to pull them out too early – extra roasting time allows moisture to fully evaporate and the starches to set for maximum crunch.

Storing Potatoes Improperly

How you store potatoes prior to cooking can also affect crispiness. Potatoes stored in the refrigerator for too long will convert their starch to sugar, resulting in excessive browning when roasted.

Additionally, wet or damp potatoes from improper storage won’t get as crispy. Store potatoes in a cool, dark place with ventilation. Avoid the refrigerator if possible.

Some Moisture is Normal

While properly cooked roast potatoes should be quite crispy, don’t expect them to be crunchy all the way through. Some moisture inside is natural for this cooking method.

As long as you follow the steps for parboiling, oiling and high heat roasting, your roasties should achieve an excellent crispy exterior with a fluffy interior.

How to Make Perfect Crispy Roast Potatoes

Follow these steps for crisp, golden roast potatoes every time:

  1. Choose the right potatoes – starchy, floury varieties like Russet or Yukon Gold.
  2. Cut potatoes into 2 inch chunks and parboil for 10 minutes.
  3. Drain and let steam dry for a few minutes.
  4. Toss hot potatoes in oil to rough up surface.
  5. Spread in single layer on a rimmed baking sheet.
  6. Roast at 425°F for 45-60 minutes, turning halfway.

Other Tips for Crispiness

  • Use goose or duck fat for extra crispy results.
  • Toss parboiled potatoes in cornstarch for added crunch.
  • Consider double frying – fry once at a lower temp then again at high heat.
  • Use a baking steel or stone for faster browning.

Common Roasting Mistakes

Here are some other common mistakes that can prevent your roast potatoes from getting crispy:

  • Peeling the potatoes – leave the skin on!
  • Rinsing after parboiling – skip this to keep potatoes dry.
  • Getting oil on the pan instead of just on potatoes.
  • Using too much baking soda in the parboil water.
  • Not drying potatoes before adding oil.
  • Stirring or turning potatoes too frequently while roasting.

How to Reheat Leftover Roast Potatoes

While it’s best to serve roast potatoes right out of the oven, you can revive leftovers to be crispy again. Here are some reheating methods:

  • Oven: Reheat at 400°F for 10-15 minutes until warmed through and starting to crisp.
  • Frying Pan: Heat oil in a skillet over medium-high heat. Fry potatoes 5-7 minutes to re-crisp the exterior.
  • Air Fryer: Cook at 400°F for 4-8 minutes, shaking halfway.

Avoid microwaving roast potatoes if you want to retain any crispiness.

Other Ways to Use Leftover Roast Potatoes

Have extra crispy roast potatoes? Here are some delicious ways to repurpose them:

  • Chop up and add to hash or breakfast skillet.
  • Make roast potato salad.
  • Top casseroles or shepherd’s pie.
  • Make roast potato soup.
  • Use in place of croutons for salad.


With the right techniques and recipes, you can get deliciously crispy roast potatoes every time. Choose floury potatoes, parboil before roasting, use plenty of oil, and give them time and space in a hot oven. Avoid common mistakes like overcrowding, undercooking and stirring too often. With practice, you’ll be a roast potato pro!