How do I make crispy roast potatoes?
The parboil, the roughing up and the hot fat — the three things that separate genuinely crispy roast potatoes from disappointing ones.
- Difficulty
- beginner
- Time
- 1 hr 15 min
- Read
- 2 min
Short answer
Parboil floury potatoes for eight minutes, drain and shake them hard in the pan to rough up the surfaces, then roast at 200°C in fat that is already smoking hot. The rough starchy edges are what turn crisp; smooth raw potato never will.
Crispness comes from surface area and dehydration. A smooth potato has neither. Parboiling gelatinises the outer layer, shaking breaks it into a rough starchy fuzz, and hot fat fries that fuzz into a shell while the inside steams soft.
What you'll need
- Floury potatoes such as Maris Piper or King Edward
- Large roasting tin
- Goose fat, beef dripping or a neutral oil
- Colander (optional)
Step by step
- Choose a floury variety, not a waxy one.Maris Piper, King Edward, Rooster. Waxy salad potatoes hold together beautifully and never go crisp.
- Cut into even pieces, roughly the size of a small egg.Even sizing matters more than exact size — mixed sizes means some burnt and some raw.
- Parboil in salted water for 8-10 minutes from cold.They should be soft at the very edge and still firm in the middle. A knife tip should enter about 5mm easily.
- Drain thoroughly and leave to steam dry for two minutes.Surface water is the enemy. It has to boil off before crisping can start, and that wastes oven time.
- Put the lid on the pan and shake it hard.This is the step that makes the difference. You want a shaggy, floury surface on every piece.
- Heat the fat in the tin in the oven until it shimmers or smokes faintly.Adding potatoes to cold fat means they absorb it and go greasy instead of frying.
- Add the potatoes in a single layer and turn to coat.Crowding traps steam. Use two tins rather than one overloaded one.
- Roast at 200°C for 45-60 minutes, turning once at the halfway point.Turn them once, not repeatedly — each turn interrupts the crust forming.
Tips
- A teaspoon of semolina or plain flour tossed through after shaking gives an even crisper shell.
- Salt them after roasting rather than before. Salt draws moisture to the surface at exactly the wrong moment.
- If they need to wait, keep them in a low oven uncovered. Covering them turns the crust soft within minutes.
Common mistakes
- Skipping the parboil — Raw potato roasted from cold produces a leathery skin, not a crisp crust.
- Adding potatoes to cold fat — They soak it up as it heats and end up greasy and heavy rather than crisp.
- Crowding the tin — Steam has nowhere to go, and steamed potatoes cannot crisp no matter how long they roast.
Questions people ask
Why are my roast potatoes not crispy?
Usually one of three things: a waxy variety, no parboil-and-shake, or fat that was not hot enough when they went in. Crowding the tin is a common fourth.
What is the best fat for roast potatoes?
Goose fat and beef dripping give the best flavour and handle high heat well. Sunflower or rapeseed oil works nearly as well. Olive oil burns and tastes bitter at roasting temperatures.