These roasted potatoes use a small amount of baking soda in the parboiling water to rough up the potato surfaces, creating a starchy coating that browns into a crisp crust. The centers stay tender while the outsides turn deeply golden, and the method works with everyday pantry ingredients.
Ingredients
- 2 pounds (900 g) Yukon Gold or russet potatoes
- 2 quarts (about 1.9 L) water, or enough to cover the potatoes
- 1 teaspoon baking soda
- 1 tablespoon kosher salt for the cooking water, plus more to taste
- 5 tablespoons (75 ml) olive oil, avocado oil, or other high-heat cooking oil
- 3 garlic cloves, finely grated or minced (optional)
- 1 teaspoon chopped fresh rosemary or thyme, or ½ teaspoon dried herbs (optional)
- ¼ teaspoon freshly ground black pepper
- 1 tablespoon chopped parsley, for serving (optional)
Instructions
- Heat the oven and prepare the pan. Place a rack in the center of the oven and heat it to 450°F (230°C), or 425°F (220°C) for a convection oven. Put a large, sturdy rimmed baking sheet in the oven as it heats. A hot pan helps the potatoes start browning as soon as they are added.
- Cut the potatoes. Scrub the potatoes and peel them if you prefer; peeling is optional. Cut them into roughly 1½-inch chunks, keeping the pieces as even as possible so they cook at the same rate. If using russets, peel them for a more even finish, though leaving the skins on is fine.
- Parboil with baking soda. Put the potatoes in a large saucepan and cover with the water. Stir in 1 tablespoon kosher salt and 1 teaspoon baking soda. Bring to a boil over high heat, then reduce the heat to maintain a lively simmer. Cook for about 8–10 minutes, until a knife enters the outside of a chunk easily but the center still offers some resistance. Check early; the potatoes should not be falling apart.
- Drain and rough up the surfaces. Drain the potatoes thoroughly in a colander and let them steam-dry for 2–3 minutes. Return them to the empty pot. Add the oil, then shake the pot gently for 10–15 seconds, or stir carefully with a spoon, until the edges look fuzzy and a thin starchy coating clings to the chunks. That rough surface is what forms the crunchy crust.
- Season and arrange. Carefully remove the hot baking sheet from the oven. Spread the potatoes over it in a single layer, leaving a little space between pieces. Season with black pepper. If using dried herbs, add them now; save fresh herbs and garlic for later so they do not burn during the long roast.
- Roast until crisp. Roast for 20 minutes without moving the potatoes. Turn the chunks with a thin spatula, then roast for another 20–30 minutes, turning once more if needed, until several sides are deeply golden and crisp. Total roasting time is usually 40–50 minutes and depends on the potato variety, chunk size, and oven. If the potatoes are browning too quickly, reduce the oven to 425°F (220°C).
- Add delicate flavorings and serve. During the final 5 minutes, toss the potatoes with the garlic and fresh herbs, if using, and return them to the oven. Taste and add salt as needed. Scatter with parsley and serve hot, when the crust is at its crispest.
Tips
- Choose a suitable potato. Russets have a fluffy interior and usually make the crunchiest crust. Yukon Golds are waxier, hold their shape well, and have a buttery texture. Both work; avoid cutting the pieces too small, since they can break apart during parboiling.
- Measure the baking soda carefully. One level teaspoon for 2 pounds of potatoes is enough to soften the surface. Too much can leave an alkaline or soapy taste and make the chunks fall apart. Use baking soda, not baking powder.
- Dry before roasting and avoid crowding. Letting steam escape after draining helps the oil coat the potatoes rather than cling to water. Use two sheets if necessary; crowded potatoes steam instead of browning. Keep the pieces in a single layer.
- Season at the right time. Salt in the cooking water flavors the interior, but still taste before serving. Garlic, delicate fresh herbs, and grated cheese can scorch if exposed to high heat for the entire roast, so add them near the end.
Serving Suggestions
Serve these potatoes as a side with roast chicken, steak, grilled fish, sausages, or a vegetable main such as lentil loaf. They also make a satisfying brunch side with eggs. For dipping, offer garlic aioli, sour cream, or a simple mix of Greek yogurt, lemon juice, and chopped herbs. A squeeze of lemon or a splash of vinegar just before serving cuts through the richness without softening the crust too much.
Variations
For a smoky version, toss the potatoes with ½ teaspoon smoked paprika and black pepper before roasting. For a lemon-herb finish, add grated lemon zest and chopped parsley after baking. You can replace the olive oil with duck fat or beef tallow for a richer flavor; keep the quantity the same and make sure the fat is hot before adding the potatoes. For a dairy-free, vegan version, use olive or avocado oil and skip cheese-based toppings. Avoid adding wet sauces to the roasting pan, as they prevent crisping.
Storage and Reheating
Cool leftovers promptly and refrigerate them in a covered container within 2 hours of cooking, or within 1 hour if the room is hotter than 90°F (32°C). Keep them refrigerated at 40°F (4°C) or colder and use within 3–4 days. For best texture, reheat in a single layer on a baking sheet at 425°F (220°C) for about 10–15 minutes, turning once, until hot and crisp. An air fryer at 375°F (190°C) usually takes 5–8 minutes. A microwave reheats the centers quickly but leaves the crust soft. Reheat leftovers to 165°F (74°C); discard potatoes left at room temperature beyond the safe time limits.
Frequently Asked Questions
What does baking soda do to roasted potatoes?
It makes the parboiling water more alkaline, which breaks down some of the potato’s surface and releases starch. Shaking the drained chunks coats them with that starch, which browns into a crisp, craggy exterior in the oven.
Can I taste the baking soda?
Not when you use the measured amount and drain the potatoes well. Using more than 1 teaspoon for 2 pounds can create an unpleasant alkaline taste, so measure level rather than estimating.
Can I prepare the potatoes ahead?
You can parboil and rough up the potatoes several hours ahead. Let them cool, refrigerate them in a covered container, then roast straight from the refrigerator, allowing a few extra minutes for browning. For the best texture, do not leave cooked potatoes at room temperature for more than 2 hours.
Why are my potatoes not crispy?
Common causes include wet potatoes, a crowded pan, an oven that has not fully heated, or turning them too often before a crust forms. Steam-dry them, preheat the baking sheet, give each chunk space, and wait about 20 minutes before the first turn.
Can I use a different oil?
Yes. Avocado, canola, sunflower, and other neutral oils suitable for high-heat cooking all work. Olive oil is also suitable at this oven temperature. Use enough to coat the potatoes lightly, but avoid pooling oil on the tray.
Do I need to peel the potatoes?
No. Scrubbed skins are fine and add texture. Peeling is a matter of preference; russets tend to have tougher skins than Yukon Golds, so many cooks peel russets but leave Yukon Golds unpeeled.