Crispy roast potatoes need floury potatoes such as Maris Piper or King Edward, parboiled for 10 minutes, roughed up in the colander, then roasted in very hot fat at 200°C fan for 45 to 50 minutes. Hot fat and roughed edges are the two non-negotiables.
Quick Answer
Peel 1kg of Maris Piper potatoes, cut into 5cm chunks, parboil in salted water for 10 minutes, drain, then shake vigorously in the colander to rough up the edges. Preheat 4 tablespoons of goose fat, beef dripping or vegetable oil in a roasting tin at 200°C fan for 8 minutes. Tip the potatoes into the hot fat, coat well, then roast for 45 to 50 minutes, turning once at 25 minutes, until deeply golden and shatteringly crisp.
What is the best potato for roasting?
Maris Piper is the best all-round roasting potato in the UK because its high starch content produces a floury interior that fluffs up when roughed, giving crisp edges and a soft centre. King Edward, Rooster and Desiree also roast well; waxy potatoes such as Charlotte or new potatoes turn dense and never crisp properly.
Why floury potatoes matter
Floury potatoes contain around 20 per cent starch by weight compared with 16 per cent in waxy varieties. That extra starch swells during parboiling and creates the microscopic ridged surface that soaks up fat and turns to a glass-like crust in the oven. Waxy potatoes hold their shape but stay smooth-skinned and pale, which is exactly the opposite of what you want.
How do you get roast potatoes crispy?
Three things create genuinely crispy roast potatoes: parboiling until the edges are just starting to soften, roughing up the surface aggressively in the colander, and roasting in fat that has been preheated for at least 8 minutes at 200°C fan. Skip any one of the three and you get a decent potato, not a great one.
The parboil
Bring salted water to the boil, add the potato chunks, and cook for 10 minutes from the moment the water returns to a simmer. Test with a fork — it should meet resistance but the outer 3mm should feel soft. Drain immediately and leave in the colander for 2 minutes to steam-dry; wet surfaces do not crisp.
The rough-up
Put the lid on the empty pan, tip the drained potatoes back in, and shake hard for 10 seconds. You want the outsides to look pale and fluffy, almost frayed. This is where the crust comes from; a gentle stir is not enough.
What is the best fat for roast potatoes?
Beef dripping produces the crispiest, most savoury roast potatoes; goose fat is a close second and gives a slightly sweeter, more aromatic finish. Sunflower or vegetable oil works well and is neutral in flavour. Butter alone burns at roasting temperatures and should be avoided; olive oil is fine but less traditional.
Expert Insight
“Home cooks rarely use enough fat. For 1kg of potatoes you need at least 4 tablespoons — about 60ml — spread across the whole base of the tin. If the potatoes are sitting in a puddle of fat when you tip them in, you have the right amount. Too little and they steam; too much only makes them richer, never soggy. When in doubt, add another spoon.”
Do you need to parboil roast potatoes?
Yes. Parboiling is what converts raw potato into the floury surface that roasts to a crust. Skipping the parboil produces roast potatoes that are dense, waxy on the outside and take almost twice as long to cook through. Ten minutes at a rolling boil is the standard for 5cm chunks.
The bicarbonate of soda trick
Adding half a teaspoon of bicarbonate of soda to the parboiling water raises the pH slightly, which breaks down the potato surface further and produces even more fluffy edges. This is Heston Blumenthal’s tweak and it genuinely works; use it once and you will never go back.
What temperature and how long for roast potatoes?
Roast at 200°C fan (220°C conventional) for 45 to 50 minutes, turning the potatoes once at the 25-minute mark and again at 40 minutes if the tops are still pale. A hot oven is essential; lower temperatures produce a soft, pale result whatever else you do.
Timings by tray size
- 500g potatoes: 40 to 45 minutes at 200°C fan
- 1kg potatoes: 45 to 50 minutes at 200°C fan
- 1.5kg potatoes: 55 to 60 minutes at 200°C fan, in a large tin so they do not touch
Give each potato at least 2cm of space around it. Crowding is the second most common home cook mistake after not using enough fat; crowded potatoes steam each other rather than roast, and you end up with the tray-of-mash effect.
Can you make roast potatoes in advance?
Parboil and rough up your potatoes up to 24 hours ahead, cool them completely, then refrigerate uncovered on a tray so the surface dries out. When you are ready to roast, tip them straight from the fridge into hot fat. Chilled, dry surfaces actually crisp better than freshly parboiled ones.
Freezing par-cooked potatoes
Parboiled and roughed potatoes freeze well for up to 3 months. Freeze on a tray in a single layer, then bag them once solid. Cook from frozen — do not defrost — adding 10 minutes to the roasting time. This is how most pubs and restaurants produce reliable roasts at scale.
Our Take
The perfect roast potato is not a mystery — it is Maris Piper, beef dripping, and a properly preheated tin. Every “chef’s secret” you read about (semolina coatings, vinegar in the water, five different herbs) is a nice-to-have on top of that. Get the fundamentals right, use enough fat, and give them the space they need in the tin, and you will beat 90 per cent of Sunday lunches out there.
How do you season roast potatoes?
Season with flaky sea salt as soon as the potatoes come out of the oven, while the surface is still glossy with hot fat. For extra flavour, add whole unpeeled garlic cloves and sprigs of rosemary to the tin at the halfway point — earlier and they burn, later and they do not release their oils.
Flavour add-ins that work
Rosemary and garlic are the British classic. For a punchier finish, sprinkle finely grated Parmesan over the potatoes for the last 5 minutes. Smoked paprika mixed into the fat before roasting gives a warm, deep colour. Lemon zest added at the end with the salt brightens the whole plate — try it with roast chicken.
Why are my roast potatoes soggy?
Soggy roast potatoes have four common causes: waxy potatoes instead of floury, insufficiently preheated fat, too little fat, or a crowded tray. Fix these four and sogginess disappears. A fifth cause, more subtle, is not shaking off enough surface water after parboiling — always give them 2 minutes to steam-dry in the colander.
Key Takeaways
- Use Maris Piper, King Edward or Rooster — floury varieties with around 20 per cent starch.
- Parboil 5cm chunks for 10 minutes in salted water, then steam-dry for 2 minutes.
- Rough the edges hard in the pan for at least 10 seconds — this is where the crust comes from.
- Preheat at least 4 tablespoons of fat per 1kg of potatoes for 8 minutes at 200°C fan.
- Roast for 45 to 50 minutes, turning once at 25 minutes, giving each potato 2cm of space.
- Season with flaky salt straight out of the oven, and add rosemary or garlic at the halfway point.
The right pan makes the difference. A shallow steel or cast-iron tin conducts heat far better than a deep ceramic dish, which is why professional kitchens use them. If your Sunday-roast tin is looking greasy and grim, our guide to How to Clean a Washing Machine covers the same principles of deep-cleaning appliances; a scrupulously clean roasting tin sears potatoes far more evenly than a coated one.
Frequently Asked Questions
Can I roast potatoes without parboiling?
You can, but they will not be genuinely crispy. Unparboiled potatoes roast into hasselback-style wedges — nice, but a different dish. If you must skip the parboil, cut the potatoes smaller (3cm chunks), toss in oil and roast for 50 to 55 minutes. Accept that they will be denser and less fluffy inside.
Do you cover roast potatoes with foil?
No. Covering roast potatoes with foil at any point creates steam and destroys the crust. If the tops are browning too fast before the insides cook, drop the oven temperature by 10°C rather than covering. Roast potatoes need dry heat from start to finish.
How many roast potatoes per person?
Allow 250g of raw potato per adult for a Sunday roast, or 150g if you are serving alongside a heavy meat course with Yorkshire puddings, stuffing and gravy. For a full 6-person Sunday lunch, 1.5kg is the standard. Nobody has ever complained about leftover roast potatoes.
Can you reheat roast potatoes?
Yes. Reheat leftover roast potatoes in a single layer at 200°C fan for 8 to 10 minutes; they will re-crisp beautifully. Microwaving turns them soft and rubbery — always use the oven or an air fryer at 190°C for 6 to 7 minutes.
Should I peel roast potatoes?
Traditional British roast potatoes are peeled, but leaving the skin on works well with new-season Roosters or waxy-floury hybrids in autumn. Skin-on potatoes are less fluffy and more chewy on the outside, which some prefer; peel them for maximum crunch and a paler, more elegant finish on the plate.
Sources
- British Potato Council / AHDB Potatoes — Potato variety guide. Starch content and roasting suitability of Maris Piper, King Edward and Rooster.
- BBC Good Food — Perfect roast potatoes recipe. Standard parboil-and-rough method with goose fat at 200°C fan.
- Which? — Best fats for roast potatoes: taste test. Comparative results on beef dripping, goose fat and vegetable oil.
- Food Standards Agency — Cooking food safely at home. Guidance on cooking temperatures and cross-contamination in a shared roasting tin.
