Burger King's latest Japanese creation.
Meet Burger King's latest Japanese creation, the 'Kuro Diamond', coloured with bamboo charcoal. Photo: Supplied

Fast food chains are often instigators of unusual innovation - remember the hamburger patty stuffed pizza crust? Well, Burger King in Japan has just unveiled a special menu item that might challenge even the most adventurous diner. A black-coloured burger that looks like it was stolen straight from Darth Vader's lunchbox.

The 'Kuro Pearl' is a cheeseburger featuring a slice of black cheese between a couple of jet black buns. The outlet’s other new offering, the ‘Kuro Diamond’, adds tomato, lettuce and onion to the mix if you’re in a more colourful mood.    

The bun's striking black colour is due to the use of 'bamboo charcoal', while the patty’s slathered in a sauce that uses the more recognisable dark touch of squid ink.

Charcoal-smeared brioche bun on Kettle Black's lobster roll in Melbourne.
Charcoal-smeared brioche bun on Kettle Black's lobster roll in Melbourne. Photo: Patrick Scala

While the 'Kuro Pearl' is sparking double-takes and online confusion (“No, it’s not burnt,” offers The Guardian), it isn’t the first time a black burger has made restaurant menus. Japan's Burger King first gave it a run back in 2012, while European chain Quick tried it with their Star Wars-themed ‘Dark Vador’ burger that same year.

Closer to home, Sydney chef Sean Connolly debuted his ‘Black Widow’ burger at The Morrison last year, while Melbourne's Kettle Black has a lobster roll with charcoal sprinkled on top and Nora (opening its own bakery in Melbourne later this month) supplies cafes like Traveller with a sweet tart with a black pastry base that includes charcoal made from coconut shell.

Connolly remains surprised at his black burger's success; it’s now one of The Morrison's most consistent sellers.

Chef Sean Connolly launched the Black Widow burger last year. The colouring comes from vegetable carbon.
Chef Sean Connolly launched the Black Widow burger last year. The colouring comes from vegetable carbon.

“It’s kind of hard to take it off the menu, really,” says Connolly. “If we sell 100 regular burgers, we’ll sell 50 black burgers on the same day. I’m still surprised by how many people still want to eat it. One bloke came in last week and ordered three ‘Black Widows’ and a really nice bottle of wine that we decanted for him ... I think it’s become quite approachable; it’s a bit of everyday life at The Morrison now.”

Connolly’s own creation was inspired by Essex-born/Denmark-based chef Paul Cunningham and his ‘Black Dog Project’ - black pudding in a black bun. Like Cunningham's version, Connolly uses ‘vegetable charcoal’, which has no discernible flavour.

“It’s quite deceiving - I think people are shocked by how it looks black, but just tastes like brioche,” he says. “It’s just ‘controlled charcoal’, done under controlled circumstances. Everyone goes nuts about charcoal ‘cause they say it’s a health hazard, but if it’s done under a controlled environment it’s fine. There’s no flavour that comes from it; it's just black. As black as you like.”

So, will we soon see the darkness falling even wider locally, with restaurants and fast food chains sporting all-onyx menus?    

"It's already a trend," laughs Connolly. "I think The Grounds [of Alexandria] do a charcoal burger now, and there’s an ice cream parlour in Chinatown that’s doing black dessert burgers. I'm releasing an 'All-Black' burger in New Zealand soon, which I reckon will go off. It all looks a bit strange, but people go for it.”

Just make sure you’ve got whitening toothpaste ready, perhaps?