The Food Lab: How to Roast the Best Potatoes of Your Life

The Food Lab: How to Roast the Best Potatoes of Your Life is a medium American recipe that serves 6. 210 calories per serving. Recipe by J. Kenji López-Alt on YouTube.

Prep: 14 min | Cook: 1 hr 5 min | Total: 1 hr 34 min

Cost: $5.06 total, $0.84 per serving

Ingredients

  • 4 lb Russet or Yukon Gold Potatoes (cut into large chunks; skins left on for texture)
  • 1 oz Kosher Salt (≈2 tbsp; adds flavor and helps draw moisture)
  • 0.5 tsp Baking Soda (creates alkaline water to break down pectin for extra crunch)
  • 5 tbsp Extra Virgin Olive Oil (for garlic‑rosemary infusion)
  • 2 tbsp Fresh Rosemary (handful, chopped; stems removed)
  • 3 cloves Garlic (minced or pressed)
  • 2 tbsp Fresh Parsley (chopped, for finishing)
  • to taste Freshly Cracked Black Pepper (season potatoes before roasting)

Instructions

  1. Boil Potatoes in Alkaline Water

    Fill a large pot with 2 quarts of water, add 1 oz salt and ½ tsp baking soda. Bring to a rolling boil, then add the 4 lb of potato chunks. Boil until a knife easily pierces and the exterior starts to fall apart, about 10 minutes.

    Time: PT10M

    Temperature: Boiling

  2. Make Garlic‑Rosemary Infused Oil

    While the potatoes boil, heat 5 tbsp extra‑virgin olive oil in a skillet over medium heat. Add the chopped rosemary and minced garlic, season with a pinch of salt and pepper, and cook until the garlic just begins to turn golden, about 5 minutes. Immediately strain the oil into a large bowl, discarding the solids.

    Time: PT5M

    Temperature: Medium

  3. Drain and Dry Potatoes

    Drain the boiled potatoes in a colander and let them sit for 2 minutes to steam off excess moisture. Do not rinse; the starch left on the surface aids crisping.

    Time: PT2M

  4. Rough Toss with Oil

    Transfer the hot potatoes to the bowl containing the strained garlic‑rosemary oil. Add a pinch of salt and freshly cracked black pepper. Using a fork or your hands, gently rough‑toss, crushing some edges to create a fluffy, mashed‑potato‑like coating.

    Time: PT3M

  5. Preheat Oven and Arrange

    Preheat the oven to 450 °F (or 400 °F if using convection). Line a rimmed baking sheet with parchment or a silicone mat. Spread the potatoes in a single layer with a little space between each piece.

    Time: PT10M

    Temperature: 450°F

  6. Initial Roast

    Place the baking sheet in the oven and roast undisturbed for 20 minutes so the crust can set.

    Time: PT20M

    Temperature: 450°F

  7. Flip and Finish Roast

    After 20 minutes, flip each piece with a spatula or tongs. Continue roasting, tossing occasionally, until the potatoes are deeply browned and crisp all over, about 30–40 minutes more.

    Time: PT35M

    Temperature: 450°F

  8. Finish with Parsley

    Transfer the roasted potatoes to a serving bowl. Add any remaining garlic‑rosemary oil and the chopped parsley. Toss to coat evenly and serve immediately.

    Time: PT2M

Nutrition Facts

Calories
210
Protein
3 g
Carbohydrates
45 g
Fat
5 g
Fiber
4 g

Dietary info: Vegetarian, Vegan, Gluten-Free

Allergens: None

Last updated: April 18, 2026

Amazon Associates

Amazon Associates PartnerTrusted

As an Amazon Associate, we earn from qualifying purchases made through links on this page. This helps support our site at no extra cost to you. Clicking on ingredient or equipment links will take you to amazon.com where you can purchase these items.

The Food Lab: How to Roast the Best Potatoes of Your Life

Recipe by J. Kenji López-Alt

Kenji Lopez-Alt's method for ultra‑crispy roast potatoes uses a brief boil in salty, alkaline water and a rough toss in garlic‑rosemary infused olive oil before a high‑heat roast. The result is a crunchy, blistered exterior with a fluffy interior, perfect as a side for any dinner.

MediumAmericanServes 6

Shop all ingredients on Amazon in one click • Printable PDF with shopping checklist

Source Video
13m
Prep
1h 14m
Cook
10m
Cleanup
1h 37m
Total

Cost Breakdown

$5.06
Total cost
$0.84
Per serving

Critical Success Points

  • Boiling potatoes in water with baking soda to create an alkaline environment.
  • Roughly tossing the potatoes to create a fluffy, mashed‑potato‑like coating.
  • Roasting the potatoes undisturbed for the first 20 minutes to set the crust.
  • Flipping and continuing to roast until deeply browned and crisp.

Safety Warnings

  • Hot oil can splatter; keep a lid nearby and use long-handled utensils.
  • Boiling water and steam can cause burns; handle the pot with oven mitts.
  • The oven and baking sheet become extremely hot; use heat‑proof gloves.

Frequently Asked Questions

Everything you need to know about this recipe

Q

What is the cultural significance and history of crispy roast potatoes in American cuisine?

A

Crispy roast potatoes have become a staple side dish in American home cooking, especially for holiday meals and Sunday roasts. Their popularity grew with the rise of oven‑roasting techniques in the 20th century, offering a simple yet satisfying accompaniment to meat and gravy.

cultural
Q

What traditional regional variations of roasted potatoes exist in the United States?

A

In the Northeast, potatoes are often roasted with herbs like rosemary and thyme, while Southern versions may include Cajun spices or be fried twice for extra crunch. In the Pacific Northwest, garlic‑infused oils are common, similar to Kenji’s method.

cultural
Q

How are ultra‑crispy roast potatoes traditionally served in American holiday meals?

A

They are typically served hot, tossed with fresh herbs such as parsley or chives, and accompanied by gravies or sauces. The potatoes are placed on a warm serving platter to retain their crisp exterior throughout the meal.

cultural
Q

What occasions or celebrations are crispy roast potatoes traditionally associated with in American culture?

A

Crispy roast potatoes are a common side for Thanksgiving, Christmas, Easter brunches, and family barbecues. Their universal appeal makes them a go‑to dish for both casual gatherings and formal holiday feasts.

cultural
Q

How does Kenji Lopez‑Alt’s technique fit into the broader American side‑dish tradition?

A

Kenji’s method emphasizes scientific precision—using alkaline water and a rough toss—to achieve a texture that many home cooks struggle with. This aligns with the modern American trend of applying food science to classic comfort foods.

cultural
Q

What are the authentic traditional ingredients for crispy roast potatoes versus acceptable substitutes?

A

Traditionally the dish uses starchy potatoes, kosher salt, baking soda, olive oil, garlic, and rosemary. Acceptable substitutes include Yukon Gold for russet potatoes, avocado oil for olive oil, and dried rosemary (though fresh gives the best flavor).

cultural
Q

What other American dishes pair well with Kenji Lopez‑Alt’s crispy garlic rosemary roast potatoes?

A

They pair beautifully with roasted turkey, beef brisket, grilled chicken, or a hearty mushroom gravy. A simple green salad or steamed asparagus balances the richness of the potatoes.

cultural
Q

What makes Kenji Lopez‑Alt’s crispy garlic rosemary roast potatoes special in American cuisine?

A

The use of baking soda in the boiling water creates an alkaline environment that breaks down pectin, dramatically increasing surface roughness and crunch. Combined with a rough toss in herb‑infused oil, the potatoes achieve a uniquely airy crust.

cultural
Q

What are the most common mistakes to avoid when making Kenji Lopez‑Alt’s crispy garlic rosemary roast potatoes?

A

Common errors include skipping the baking soda, overcrowding the baking sheet, and moving the potatoes during the first 20‑minute roast. Each mistake prevents the formation of the signature blistered crust.

technical
Q

Why does this recipe use a rough toss instead of gently coating the potatoes with oil?

A

Rough tossing crushes the outer edges of the boiled potatoes, creating a fluffy, mashed‑potato‑like layer that fries up into extra‑crisp micro‑blisters. A gentle coating would leave a smoother surface and result in less crunch.

technical
Q

Can I make Kenji Lopez‑Alt’s crispy garlic rosemary roast potatoes ahead of time and how should I store them?

A

Yes. Boil and dry the potatoes up to a day ahead, keep them uncovered in the refrigerator, and store the infused oil separately. Re‑roast in a preheated 425°F oven for 5‑10 minutes before serving to restore crispness.

technical
Q

What does the YouTube channel J. Kenji López‑Alt specialize in?

A

The YouTube channel J. Kenji López‑Alt focuses on food science‑based cooking, breaking down classic recipes with detailed explanations, experiments, and practical techniques for home cooks.

channel
Q

How does the YouTube channel J. Kenji López‑Alt's approach to American side‑dish cooking differ from other cooking channels?

A

Kenji’s approach combines rigorous scientific testing with clear, step‑by‑step visuals, often revealing counter‑intuitive tricks—like using baking soda in boiling water—that other channels may overlook. This makes his side‑dish tutorials both educational and highly reliable.

channel

You Might Also Like

Similar recipes converted from YouTube cooking videos

Easy Roasted Duck Fat Potatoes - The BEST Potato Recipe!
5

Easy Roasted Duck Fat Potatoes - The BEST Potato Recipe!

Crispy, golden‑brown potatoes roasted in rich duck fat and flavored with fresh thyme, rosemary, and garlic. Boiled first in chicken stock for extra fluffiness, then roasted until perfectly crunchy on the outside and fluffy on the inside. Ideal as a luxurious side for duck confit, roasted chicken, or beef tenderloin.

1 hr 45 minServes 6$10
French
Crispy Duck Fat Roast Potatoes
5

Crispy Duck Fat Roast Potatoes

Crispy, fluffy roasted potatoes cooked in duck fat and finished with a fragrant rosemary sea‑salt blend. Perfect as a festive side for Christmas or any holiday feast.

2 hrs 20 minServes 6$14
British
Duck Fat Potatoed
2

Duck Fat Potatoed

Golden, ultra‑crispy roast potatoes cooked in rich duck fat. The potatoes are par‑boiled, tossed in melted duck fat, and roasted until the edges are crunchy and the interior stays fluffy. Perfect as a side for holiday meals or any dinner that needs a decadent carb boost.

1 hr 20 minServes 4$8
French
Christmas beef fat roast potatoes 🥔
4

Christmas beef fat roast potatoes 🥔

A festive side dish perfect for holiday meals: potatoes boiled, shaken for fluffiness, then deep‑fried in beef tallow for ultimate crispness, finished with rosemary and salt.

1 hr 20 minServes 4$6
British
The Best Lemon Vinaigrette For Salads, Grilled Veggies and More! 🍋
3

The Best Lemon Vinaigrette For Salads, Grilled Veggies and More! 🍋

A bright, tangy lemon vinaigrette made with olive oil, fresh lemon juice and zest, garlic, Dijon mustard, salt and pepper. Perfect for drizzling over salads, roasted veggies, or as a simple dip.

12 minServes 4$2
American
Is this really the best salad recipe ever? 🤔🧐
6

Is this really the best salad recipe ever? 🤔🧐

A super simple, crisp iceberg lettuce salad dressed with lemon juice, a splash of vinegar, garlic, salt, and pepper. This minimalist side dish highlights the fresh crunch of iceberg lettuce and can be tossed in under 15 minutes.

20 minServes 4$2
American
CHICKEN THIGH SHEET PAN DINNERS / COOK WITH ME
4

CHICKEN THIGH SHEET PAN DINNERS / COOK WITH ME

Two comforting sheet‑pan dinners featuring bone‑in chicken thighs. The first is a herb‑marinated roasted chicken with potatoes, carrots, onion and garlic, finished with a quick broil. The second is a sweet‑spicy honey garlic chicken paired with broccoli and carrots, glazed with a thickened sauce. Both are easy, fast, and require minimal cleanup.

2 hrs 57 minServes 8$20
American
Made Simple (5 Ingredients)
2

Made Simple (5 Ingredients)

A quick, vibrant herb‑garlic sauce that blends fresh parsley, garlic, red wine vinegar, red pepper flakes, and olive oil. Perfect as a drizzle for grilled meats, roasted vegetables, or a bright salad dressing.

27 minServes 4$1
American
The Food Lab: How to Roast the Best Potatoes of Your Life