The secret to the perfect oven chips

by Poppy O'Toole

The chip. From a bag of frozen crinkle cut to a paper-wrapped package from the local chippy, to a plate of them covered in truffle or Parmesan at a restaurant, whatever the shape or colour or topping, we are a nation of chip lovers. We have them on the side of a full English breakfast. We have them with sandwiches, we put them in sandwiches. Basically, we love all the chips.

As a chef with over 10 years’ experience, who also spends my career trying to encourage more people to cook from scratch and enjoy it more, I admit that chips are a bit of a pain for some people. Deep-frying at home isn’t always a viable option, whether it’s to keep up a healthy balance, not wanting a kitchen full of hot oil or simply not having a deep-fat fryer to hand.

And here’s another confession for you: I, a professional chef, will still sometimes get a bag of frozen chips in the oven for tea. An oven chip is just the ultimate easy side that will go with anything.

It can feel a bit of a faff to make oven chips from scratch when there’s an easy frozen option, but when you nail your first really fluffy, crisp oven-cooked chip, you won’t look back. Let’s look at the steps that go into making that perfect chip at home.

The ideal chip is all about that ultimate crisp exterior, the perfect level of fluff and a beautiful shape to dip, dunk or devour as quickly as possible.

There’s one chip-sized elephant in the room however… Will the oven chip ever be as good as ‘chippy’ chips? Why is it that deep-frying makes such good chips? In the right pair of skilled hands, the high heat and direct contact with the oil reacts with the potato perfectly, giving that fluffy centre and crispy exterior mentioned above.

Why? Because deep-frying potatoes in oil drives the water from the inside of the chip out (that’s the bubbles and steam you see in the oil) while caramelising the outside of the chip. (The famous triple-cooked chip is all about trying to get more water out through rounds of cooking and cooling to create a fluffy inside, making sure the middle is completely cooked, before the golden crust forms on the outside.

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When deep-frying, the direct contact with the hot oil means the chip cooks from the outside in – the heat is transferred to the centre through conduction. The bubbles of steam escape from the chips creating movement within the pan, this in turn helps to circulate the oil, keeping the temperature consistent and hot.

So when making chips in an oven (rather than deep-frying them), a consistent, dry, high heat is crucial. They roast in hot circulating air, convection heat, which is uneven. The chips are hotter where they have contact with the pan and oil. If the oven isn’t hot enough to brown the chips on the 'air-side', or if there’s not space for the heat to circulate around each chip, they’ll be unevenly crisp.

Deep-frying also means the oil can penetrate the craggy, broken edges on all sides to make an extra crisp surface. Without creating these crags and crevices, and coating them with oil, the oven chip will be a pale imitation.

A new entry to the chip equation is the air fryer. You’ve probably heard of this increasingly popular kitchen gadget, whether it’s from recipes online that have gone viral or recommendations from your aunt. How does it work? The rapid air circulation from an air fryer works similarly to a fan oven, in that it circulates really hot air all around the food. The smaller space allows for more consistent heating and drying of the food, which can create a crisp, golden surface.

It helps to achieve a lovely chip but until this newfound gadget is in every home across the country, there are a number of ways to emulate it to create the perfect chip in the oven.

First up, for the perfect chip you need the perfect potato. You should know by now that my MVP (Most Valuable Potato) is the Maris Piper – for roast potatoes, for mashed potatoes and for chips. It has a heap of great qualities for the job, but most importantly it’s a starchy spud so will give you that fluffy centre and crisp outside required.

A close second would be the King Edward. It’s slightly waxier, which keeps its structure when cooked, resulting in a more solid chip. However, having probably peeled and chopped 100 tonnes of potato in the last two years, in my experience I would say the fluffier feel of a Maris Piper makes for the better chip.

I’ve tested and tasted many potatoes. I believe I’ve found the techniques everyone needs to know when making oven chips.

First, it’s all about prepping your potatoes correctly. When you cut your chips, it’s integral that you get them straight into cold water to wash the starch off. Soak them for 2-3 minutes and then drain before putting into fresh water to boil. This will prevent them browning too quickly and ensure you don’t end up with soggy chips.

Just like roasties, always parboil your potatoes before they go into the oven as this will help make them fluffy and make those soft edges on the surface that will crisp up. Add the raw chips to a large pan with salted cold water and bring them to boil. Cook them for around 7-10 minutes until they are tender. Keep an eye on the clock because you don’t want to overboil at this point and have your potatoes lose their shape. (Or end up with soup.)

Next up is the importance of stream-drying. Get those boiled, steamy spuds spread out on a cooling rack with a tea towel over them. I’d suggest leaving them like this for at least 10 minutes which will dry out the chips and help towards the optimum mix of crispy and fluffy.

Now for the high heat. You need to get the oil (a good couple of tablespoons, no skimping) really hot. Preheat the oven to around 220 degrees Celsius (200C Fan or Gas Mark 7) with a tray of oil inside. You want a sizzle when those dried potatoes hit the oil. Then you know the magic is happening. And don’t put too many chips on the tray. Remember, the heat needs to circulate around the surface of each chip, so no crowding. Use two trays. You’re worth it.

Leave them in for about 40-50 minutes, checking by eye for the perfect golden colour. My final tip is to only turn them ONCE. It’s the same rule I always use when cooking roast potatoes; don’t pester your spuds too much so they'll have more time to get nice and crispy all over.

Then it’s just a question of serving: flaky salt, ketchup, mayo, vinegar, loaded like nachos, it’s all good. As my parting gift, I’ve done an easy version of the Canadian poutine. We’re talking cheesy, gravy-covered chips. I know the thought of mixing our cheeses with our gravies is very unBritish, but it’s lovely, and a meal in itself.

I really do think I’ve cracked the formula to achieving perfect oven chips at home… even if you do still throw in a bag of frozen fries into the oven every once in a while!

Originally published June 2022