Proper roast potatoes usually mean parboiling, draining, roughing up and an hour in a hot oven. In the air fryer you can skip the parboil and still get golden, crunchy edges with a soft middle, in about 30 minutes.
The trick that replaces parboiling is a light dusting of cornflour after the oil. It sticks to the cut sides and fries into a thin, crisp shell. A short soak in cold water first removes surface starch so the potatoes do not go gluey.
Below are the times for a standard 5–6 litre basket, how to cook a bigger batch, and how to reheat leftovers so they crisp up again.
Ingredients
- 800 g (1¾ lb) floury potatoes — Maris Piper, King Edward or russet
- 1½ tbsp vegetable, sunflower or olive oil
- 1 tbsp cornflour (cornstarch)
- ¾ tsp salt
- ½ tsp garlic granules (garlic powder)
- ½ tsp dried rosemary or thyme
- A few grinds of black pepper
Instructions
- Cut the potatoes: Peel the potatoes and cut them into even chunks of about 4 cm (1½ inches). Even sizes cook at the same speed.
- Soak: Cover the chunks with cold water and leave for 15–30 minutes to wash off surface starch. Skip this if you are short of time; they will be a little less crisp.
- Dry very well: Drain and pat the potatoes completely dry with a clean towel. Wet potatoes steam instead of crisping.
- Coat: Toss the potatoes with the oil in a bowl, then sprinkle over the cornflour, salt, garlic granules, rosemary and pepper and toss again until every piece has a thin, even coating.
- Heat the air fryer: Set it to 200 °C (400 °F) and let it heat for 3 minutes.
- Air fry: Spread the potatoes in the basket in a single layer, with a little space between them. Cook for 25–30 minutes, shaking the basket every 10 minutes.
- Check: They are done when deep golden and crisp outside and a knife slides into the middle easily. Give them 3–5 minutes more if needed, then serve straight away.
Tips for the best result
- Do not overcrowd the basket: 800 g suits a 5–6 litre basket. In a smaller one, cook in two batches and keep the first warm in a low oven.
- Floury potatoes give fluffy middles; waxy ones such as Charlotte stay firm and do not crisp as well.
- For a Sunday roast, cook the potatoes last while the meat rests — they take the same 30 minutes the meat should rest.
- Want them even crunchier? Roughen the edges by shaking the coated potatoes in a covered bowl before they go in.
Storing and reheating
Cool leftovers and refrigerate within 2 hours; eat within 3 days. Reheat in the air fryer at 190 °C (375 °F) for 5–7 minutes until piping hot and crisp again.
Frequently asked questions
Do you need to parboil potatoes for the air fryer?
No. Cut them into 4 cm chunks, soak and dry them, then coat them in oil and a little cornflour. They cook through and crisp in 25–30 minutes at 200 °C.
How long do roast potatoes take in the air fryer?
25–30 minutes at 200 °C (400 °F) for 4 cm chunks, shaking every 10 minutes. Smaller pieces need about 20 minutes.
Why are my air fryer potatoes not crispy?
The usual reasons are wet potatoes, too many in the basket, or no oil. Dry them well, cook in a single layer and use about 1½ tablespoons of oil for 800 g.
Can I make them without cornflour?
Yes, they will still brown, just with a less crunchy shell. Plain flour or semolina also works.
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