Name: Crispy Roast Potatoes
Prep time: 20 min
Cook time: 60 min
Total time: 80 min
Yield: About 6 side-dish servings
Cuisine: British-inspired
Ingredients: 1.5 kg russet or Yukon Gold potatoes, peeled and cut into large, even chunks — Large chunks give a strong crisp-outside/fluffy-inside contrast.; 2 L water; 2 tbsp kosher salt — Season the cooking water; adjust if using fine table salt.; 1/2 tsp baking soda — A mildly alkaline boil helps soften the exterior so it can rough up into a crisping starch layer.; 4 tbsp olive oil — Use enough to coat the roughened surfaces, not to pool on the tray.; 1 tsp fresh rosemary, finely chopped — Optional.; 2 cloves garlic, finely minced — Optional; add late or infuse the oil so it does not burn during the full roast.; black pepper, freshly ground — To taste.

Before you start

What this method is trying to achieve

This CookClue method is designed around the failures that usually stop roast potatoes from crisping. The potatoes are parboiled until the centers are nearly tender, drained until surface moisture is gone, deliberately roughed up to create a starchy coating, then roasted hot and uncrowded until the crust is deep golden. The timer is a guide; the visible surface is the real endpoint.

Success looks like

Know the target before you cook

The finished potatoes should have a dry, crackly, deeply browned exterior with visible rough edges and a fluffy or creamy center. When you press a hot piece lightly with a fork, the crust should resist before the interior gives way.

Ingredients

What you need

Potatoes

1.5 kg russet or Yukon Gold potatoes, peeled and cut into large, even chunks — Large chunks give a strong crisp-outside/fluffy-inside contrast.

Parboil

2 L water
2 tbsp kosher salt — Season the cooking water; adjust if using fine table salt.
1/2 tsp baking soda — A mildly alkaline boil helps soften the exterior so it can rough up into a crisping starch layer.

Roast

4 tbsp olive oil — Use enough to coat the roughened surfaces, not to pool on the tray.

Finish

1 tsp fresh rosemary, finely chopped — Optional.
2 cloves garlic, finely minced — Optional; add late or infuse the oil so it does not burn during the full roast.
black pepper, freshly ground — To taste.

Method

Cook by the cues, not just the clock

Prepare

Heat the oven to 230°C / 450°F conventional, or about 205°C / 400°F convection, with a rack near the center. Have a large rimmed metal baking sheet ready.
Critical cueThe oven should be fully preheated before the potatoes go in.

Parboil

Bring the water to a boil with the salt and baking soda. Add the potato chunks, return to a gentle boil, then simmer until a thin knife enters the center with little resistance while the chunks still hold their shape, usually about 8 to 12 minutes after the water returns to temperature.
Critical cueThe center should be almost tender; the edges should look softened, not completely collapsed.

Dry and rough

Drain thoroughly. Leave the potatoes in the hot colander or pot for 1 to 2 minutes so visible steam can escape. Add the oil and toss firmly enough to scuff the edges and build a rough, mashed-potato-like coating on the surface.
Critical cueThe surface should look dry, fuzzy and rough — not wet and polished.

Roast

Spread the potatoes on a large rimmed metal baking sheet in one layer with space between pieces. Roast without moving for about 20 minutes so the first crust can set. Turn with a thin spatula, then continue roasting 30 to 40 minutes, turning once or twice more, until deeply browned and crisp on multiple sides.
Critical cueDo not flip early if the bottoms are still sticking; once a crust forms they release much more cleanly.

Finish

Season while hot. If using garlic or delicate herbs, add them near the end or toss them through after roasting so they do not burn during the long high-heat stage. Serve uncovered and promptly.
Critical cueDo not cover the tray after roasting; trapped steam softens the crust.

Critical checkpoints

Stop here and check

visual

Before roasting: is the surface dry and rough?

The chunks should have visibly scuffed, floury-looking edges with no water pooling on them.

If they are glossy or wet, let them steam-dry longer before adding more fat. A wet surface will spend oven time steaming instead of browning.

texture

At the first turn: did a crust actually set?

The underside should be golden and should release with a thin spatula instead of smearing or sticking like wet potato paste.

If the potatoes are still pale and glued to the tray, leave them undisturbed longer. If the tray is crowded or wet, separate the pieces before continuing.

timing

At serving: were they crisp and then softened?

The potatoes left the oven crisp but became soft while sitting, especially if covered or piled deeply.

Move them back to an uncovered hot tray for a short re-crisp and serve without trapping steam.

If yours looks different

Route the failure before changing the recipe

The potatoes are pale, soft, browned without crunch, or crisp at first and then softened.Roast potatoes still not crispy? Diagnose the exact failure pattern.

Why Are My Roast Potatoes Not Crispy?

The potato chunks break down outside while the centers are still firm during the parboil.Soft outside but hard inside during the boil? Check the heat-gradient diagnosis.

Why Are My Potatoes Mushy Outside but Hard Inside?

After cooking

Storage, reheating & substitutions

Storage

Cool leftovers promptly and refrigerate in a covered container. For best texture, avoid stacking them while they are still steaming.

Reheating

Reheat uncovered on a metal tray in a hot oven until the exterior is dry and crisp again. A microwave will heat the center but softens the crust.

Substitutions

Russets produce a fluffier center and especially crisp rough edges; Yukon Golds produce a creamier center and can brown more deeply. Olive oil works well; another high-heat cooking fat can be used if its flavor suits the meal.

Evidence

Sources & methodology

Technical claims and method decisions are tied to sources. Recipe-specific advice is not presented as a universal food-science law.

The Best Crispy Roast Potatoes EverSerious Eats
Serious Eats documents alkaline parboiling with baking soda, roughing the softened exterior into a starchy slurry, high-heat roasting at 450°F / 230°C (400°F / 200°C convection), a first 20-minute undisturbed roast, and visual monitoring because browning time varies by potato.
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