Martin Lewis' air fryer warning explained as Black Friday approaches

Black Friday is approaching (with some sales already starting) and for plenty of people, it’s a chance to sort Christmas presents early.

Meanwhile, others might be using it as a chance to have a bit of a winter wardrobe refresh or to treat themselves to a new telly.

And perhaps you’ve decided it’s the perfect time to finally get that kitchen gadget that practically everyone else already has. Obviously, I’m talking about an air fryer.

But Martin Lewis has a warning about the bits of tech that it’s worth understanding before you bag your big Black Friday purchase.

It might not always be the most cost efficient (Getty Stock)

While a lot of us reckon our air fryer is the best thing since sliced bread, the national treasure of saving us money might just turn our worlds upside down.

Yep, during an episode of The Martin Lewis Podcast, he revealed that the kitchen gadgets aren’t always the most cost-efficient for cooking your dinner.

"A microwave, I believe, gives you consistent heat whereas an oven is warming up to full temperature and then topping it up so it isn’t running at full power the whole time," he explained.

“If you were doing a full roast dinner and you were cooking many of them, that is where it's probably cheaper than putting five or six jacket potatoes in a microwave because each additional object you put in a microwave, you need to keep it on longer because a microwave just heats the individual object."

It’s not all doom and gloom for air fryer lovers though as he revealed cooking something like a jacket potato for 10 minutes in the microwave is still cheaper than whacking it in the oven for an hour and a half.

And for those of you who love a bit of maths and want to work out exactly how to know if using one or the other is cheaper, there is an equation.

Martin Lewis previously gave a warning about airfryers (David M. Benett/Alan Chapman/Dave Benett/Getty Images)

Lewis explained: “General equation is, find the wattage of an item, then work out how many kilowatts or what fraction of a kilowatt it's using, then multiply that by 34p per hour of use.

"The problem with the equation for heating equipment is an oven is going to be about 2,000W.”

"If you had a 1,000W microwave and you put it on for 10 minutes, one KWH for a sixth of an hour, a sixth of 34p is about 6p, shall we say? So it’s 6p turning the microwave on for that amount of time. So yes it’s a very useful equation."

'Which?' a consumer group, also found that the traditional method of an oven is better to cook large quantities.

But with smaller amounts with appliances like air fryers, they state: "We’ve found these products cost less to cook certain foods than conventional ovens."

Well, there you go, you might not necessarily be saving as much cash as you think by nabbing an air fryer in the Black Friday sales.