Why are my chips soggy?

Starch, water and two-stage cooking — why the professional method is two cooks rather than one long one.

Difficulty: beginner
Time: 45 min
Read: 2 min
Safety: warning

Short answer

Rinse the starch off, dry them completely, and cook them twice — once gently to cook through, once hot to crisp. One long cook gives you either raw middles or soggy outsides.

A good chip is cooked through inside and dehydrated and crisp outside, and those need different temperatures. Trying to achieve both in one go is why home chips disappoint.

Safety

If deep frying, never fill a pan more than a third full, never leave it unattended, and never put wet or frozen chips into hot oil — water flashes to steam and ejects boiling oil. See the deep frying guide for the full safety procedure.

What you'll need

Floury potatoes
Oil
Kitchen paper
Thermometer (optional)

Step by step

Use a floury potato.Maris Piper, King Edward, Russet. Waxy potatoes have too much moisture and not enough starch, and they will not go fluffy inside.
Cut them evenly and rinse off the starch.Under cold water until it runs clear, or soak for half an hour. Surface starch is what makes chips stick together and go gummy.
Dry them completely.A clean tea towel, thoroughly. Water on the surface has to boil off before anything crisps, and in hot oil it is dangerous.
Parboil or blanch first.Either simmer them for a few minutes until just tender, or blanch in oil at about 140°C. This cooks the inside. Then drain and cool completely.
Cool them fully before the second cook.The step that makes the difference. Cooling lets the surface dry and firm. Straight from the first cook into hot oil gives a poor crust.
Cook again at high heat.190°C for a few minutes until golden. This is the crisping stage, and it is quick.
Do not crowd the pan or tray.Batches. Overloading drops the temperature and everything steams — the same failure as with roast potatoes.
Drain, salt and serve immediately.On a rack rather than paper if you can, so steam escapes from underneath. Chips soften within minutes of being piled up.

Tips

For oven chips, the same principles apply: parboil, dry, hot oven, preheated tray, single layer, plenty of space.
The cooled par-cooked chips freeze well. Cook from frozen at high heat for genuinely good chips on a weeknight.
An air fryer works well for the second stage but needs the same preparation — rinse, dry, and do not overload the basket.

Common mistakes

Cooking once at one temperature — The inside needs gentle heat and the outside needs high heat. One cook gives you one or the other.
Not drying them — Surface water prevents crisping and, in deep fat, causes dangerous spitting.

Questions people ask

Why do I need to cook chips twice?

The inside needs a gentle cook to become fluffy and the outside needs high heat to crisp. Doing both at one temperature gives you a raw middle or a soft crust.

Do I have to soak chips?

Rinsing or soaking removes surface starch, which is what makes chips stick together and go gummy. It makes a noticeable difference.