Ninja Foodi MAX Dual Zone AF400UK review: a month of teas for two hungry lads

"Is the big Ninja worth it or is it just hype?" Somebody asked that in the Year 7 parents' WhatsApp at ten past nine on a school night. By twenty past, there were fourteen replies. Thirteen said yes, most of them with a photo of chips. The fourteenth was a dad asking if anyone had found a PE bag with a name tape saying Oliver.

I didn't need persuading that people love it. Half the kitchens on our street have one. I needed to know whether it would survive our house for a month. That's me, my partner Lee, and our two lads, Kai, who's 12 and eats like a builder, and Freddie, who's 9 and will only eat chips that are "the colour of a digestive". Not lighter, not darker. He is very clear about this.

So the Ninja Foodi MAX Dual Zone AF400UK went on the worktop of our terraced house in Leeds, and I cooked on it for 31 days. 54 cooks in total, every one written down.

Which Ninja this is, because the names don't help

Ninja sells a lot of two-drawer air fryers in Britain and the model numbers look like a password. The AF400UK is the classic: two drawers side by side, 9.5 litres in total, each drawer 4.75 litres. It's the one you see stacked up by the tills in Currys and Argos, in black, and there's a white version with the code AF400UKWH.

Its closest relative is the AF451UK, the same fryer with a wired meat thermometer that stops the cook when the inside is done. The smaller, stacked and single-drawer versions are further down, under alternatives.

I tested the plain AF400UK because it's the one most families buy, and to see if you really need the probe.

Specs at a glance

How I tested it

I paid for it at Currys like anyone else, on a Friday after work, and it made fish finger butties on the Saturday. From then on, every cook went up on the little whiteboard stuck to the fridge in Freddie's handwriting or mine: food, weight, setting, minutes, and a mark out of ten from whoever ate it.

Alongside that, I took the same readings we take for every kitchen gadget, all listed on our how we test page. An energy monitor plugged in between wall and fryer. A sound meter held a metre away. And my trusty probe thermometer in every piece of chicken, because pink chicken doesn't get served in this house, full stop.

The unofficial measure was the one I trusted most: the bin. If the lads scraped something into it, the cook failed. Over 31 days very little went in, apart from one evening with courgettes that we've all agreed never happened.

Chips, and the colour-of-a-digestive rule

Start with the classic. 900 grams of frozen oven chips in one drawer, Air Fry at 200°C, one shake at the halfway point. Done in 19 minutes, straight from the freezer, no preheat. Freddie inspected them and declared them "digestive". The same bag in our fan oven is a 41-minute job once you count warming it up, and I always end up with a mix of burnt corners and pale middles that Freddie sorts into piles.

Proper chips from Maris Pipers, cut thick, soaked for half an hour, dried and tossed in a tablespoon of oil, took 26 minutes at 200°C. Crisp outside, fluffy inside, and Lee ate four straight out of the drawer before they reached a plate. Max Crisp at 240°C is brilliant with anything frozen, nuggets and potato waffles especially. Put fresh veg or homemade chips on it and the outsides scorch before the middles cook, so for those I never went above 200°C.

One thing I learnt in week one: don't fill a drawer to the top with chips. Up to about two thirds, they crisp evenly. Above that, the bottom layer steams. The drawer holds more than it cooks well.

Sync and Match, or how tea finally arrives all at once

Two drawers are only half the story. The trick is getting them to finish together, and that's the Sync button's whole job, so it got a proper workout. Give each drawer its own time and heat, press Sync, and the fryer holds back the quicker drawer until the two line up.

A typical Wednesday: 20 minutes of chips at 200°C on the left, 12 minutes of fish fingers at 190°C on the right. The left drawer roared into life. The right one stayed dark and silent, and eight minutes later it joined in. One beep, two drawers ready, nothing going cold on a plate. On a school night at quarter to six, with Kai back from football and starving in a very vocal way, that is worth more than any feature list.

Match is for when you want the same food twice. Set the left drawer, press Match, and the right drawer takes the same settings. The night Kai had four mates round after a match, that meant 1.8 kg of chips in one go, 21 minutes, and five 12-year-olds fed without a second batch.

"It's the first time in twelve years I've sat down at the same time as everyone else." Lee, week two, with a fish finger sandwich

The jobs I didn't expect it to do: jacket spuds, a Sunday chicken and Yorkshires

Jacket potatoes were the surprise of the month. Four big baking potatoes, rubbed with oil and salt, 45 minutes at 200°C, turned once. Crackly skins, soft middles. In our oven that's 75 minutes, and nobody wants the oven on for over an hour in July. We had jackets with beans and cheese four times in the month, which in our house counts as a food trend.

A whole chicken went in one drawer on a Sunday: 1.8 kg, the biggest we could find at the supermarket, Roast at 180°C. It only just fitted, the breast coloured well before the legs did, and it took 58 minutes until my probe read 75°C in the thickest part of the thigh. Roast potatoes went in the other drawer on Sync. Juicy chicken, crisp roasties, oven off. I've done the Sunday dinner the same way twice since.

Yorkshire puddings were the test I was nervous about, because my mum reads these. I made them in a small four-hole tin that fits in one drawer, oil smoking hot first, then the batter at 200°C for 18 minutes. They rose. They leaned a bit like a row of old chimney pots, and they weren't as tall or as crisp as oven ones. Fine for a Wednesday with sausages. For Sunday with my mum at the table, the oven is staying.

What drove me up the wall

The size. 41.5 cm is a lot of worktop in a terrace kitchen. It went where the bread bin used to live, and the bread bin now lives on top of the fridge, where Freddie can't reach it, which has its own benefits. Measure your space before you order, and leave a few centimetres behind it. The vent at the back blows warm air, and after a week I could see a faint greasy film on the tiles behind it until I pulled it forward.

The beep. The end signal is loud, and there's no way to make it quieter. Freddie treats it like the school bell and races to the table, which is handy. Lee, who does early shifts and naps after work, finds it less charming.

The drawers. There's no window, so to check you pull a drawer out. It pauses and carries on when you push it back, which is clever, but you'll check far too often in week one. And with a whole chicken inside, a drawer is heavy. Use both hands and hold it by the handle, not the edge.

The cable. About 85 cm. We were lucky, the double socket is right behind it. Check yours before you order, because a 2,470 W fryer on an extension lead is not something I'd do.

Cleaning up

Both drawers and both crisper plates are allowed in the dishwasher. Ours rarely went in, because I've killed two frying pans with dishwasher tablets and I'm not doing it again. In the sink, with hot soapy water and a soft sponge, both drawers took about three minutes, even after the chicken.

Fifty-four cooks in, I tilted both drawers under the kitchen light looking for scratches and found none. House rule: nothing metal goes in. Lee got told off once for a fork, and never again. Buy some tongs with silicone tips on the same day you buy the fryer.

Noise and what it costs to run

Both drawers on full, my meter read 56 dB from a metre away. It's a low whoosh, a bit like a bathroom fan, with no whine. Two people can still argue over it about whose turn it is to feed the cat, and in our house they do.

I ran everything through the plug-in energy monitor and costed it at 25p per kWh, roughly what we pay under the price cap:

Call it 13 or 14p saved every time the oven stays off. Over five teas a week, that's about £35 a year, roughly a month of Kai's football subs. And in July the back door can stay shut.

Is it right for your kitchen?

Do you need the AF451UK with the probe?

I promised an answer. If you already own a probe thermometer and don't mind using it, no. Mine cost less than a takeaway and did the job all month. The AF451UK makes sense if you cook meat or fish several times a week and hate guessing, because it stops the drawer at the right temperature on its own. For chips, jackets, fish fingers and veg, the plain AF400UK does exactly the same job for less.

Alternatives worth a look

Ninja Foodi Dual Zone AF300UK. The little sibling at 7.6 litres, cheaper and a few centimetres slimmer. Two or three of you, it'll cope. With two lads who eat for four, I was glad of every extra bit of drawer the AF400UK gives you.

Ninja Double Stack XL (SL400UK). Stacked drawers, so it solves the worktop problem. The drawers are shallower, so a whole chicken is a squeeze.

Ninja FlexDrawer (AF500UK). One big drawer that you can split in two. Better for joints and whole chickens, and it still does two foods at once with the divider in.

Tempted by something far bigger and far dearer instead? I lived with one for 40 days in my Thermomix TM7 review. Everything else we've scored is lined up in our reviews.

After 31 days

The Ninja stays. We used it on 26 of 31 days, and the oven went on three times: two Sundays with my mum and one birthday cake. It's wide, it shouts when it's finished and it can't do a Yorkshire that would pass family inspection. But it fixed the exact problem I had, which is tea that turns up in bits.

Freddie has now added a second rule to his list: fish fingers must also be the colour of a digestive. It's on the whiteboard, underlined twice. The whiteboard is staying on the fridge.

Your Ninja AF400UK questions, answered