The epitome of coffee cool, the flat white came under fire this week as Conal Lavery of Thomson’s Coffee Roasters told Channel 4’s Supershoppers that customers were being ripped off by excessive pricing.
In Starbucks, you can expect to pay £2.40 for a tall latte (12 fl oz) with two shots of coffee, but £2.60 for a significantly smaller flat white (8 fl oz). In Caffè Nero, a medium latte is £2.50 - but a flat white will set you back £2.60.
If anything, he explained, flat whites (a double espresso shot with a single portion of textured milk) should cost less. "There is no reason for a flat white to cost any more," he said.
"The chains and the speciality independent side of the market do a double shot as standard [in flat whites as well as lattes]," he added. "So you are getting the same amount of coffee and with a flat white but with less milk. So if anything, it should cost less."
I hate the word hipster, but people are buying into the East London thing
Previously the preserve of specialists and coffee drinkers in Australia and New Zealand, where it originated, the flat white entered public consciousness a couple of years ago. It's now a mainstream choice on the high street - but still comes at a seemingly bizarre premium.
So, are hapless consumers being tricked into thinking we're buying a superior coffee? Or are we paying some sort of zeitgeist tax?
The inflated price might have something to do with the fact that the espresso-based coffee is still synonymous with the "cool" East London lifestyle, says Chloe Callow, coffee expert and editor of Caffeine Magazine.
Callow agrees that the flat white costs no more to produce than other conventional coffees - but she does say that there's an added skill in texturing the milk. A proper flat white should be made using whole milk that is steamed to microfoam consistency - this means aerating the milk less than if you were making a latte, which creates a silkier texture.
There's also an art to producing the detailed and highly Instagrammable foam art that is synonymous with a flat white. If done properly, all of this requires investment in a skilled barista.
However, Callow suggests that the other reason for the higher cost of a flat white comes from its "perceived value". Retailers are relying on the desire of consumers to be part of a trend.
"These customers are not just buying a flat white, she says. "They’re buying into a lifestyle." For Callow, the flat white represents an accessible, affordable, bite-sized portion of cool - which grants momentary inclusion into a certain tribe.
"The [flat white] trend stemmed from the rise of independent coffee shops in London - think of the stereotype of the tattooed barista."
"There are loads of them now, but when they first arrived, they were pioneers of this 'third wave' coffee scene. The flat white was less accessible back then, and seen as something a little bit different."
Third Wave coffee, for those of you who didn't get the memo, is the term for the global movement towards treating coffee as an artisan food product.
"The flat white is a small luxury but it's still affordable - it's perceived as niche, and above and beyond the everyday," continues Callow. "It's not like buying a cup of tea and a biscuit. I hate the word 'hipster', but people are buying into the East London thing, and taking a moment to feel like they're part of a different demographic.
The mystery that still surrounds coffee, she suggests, also contributes to the allure of slightly less orthodox brews. "Because coffee isn't well understood by many, it's still seen as mysterious - even by chefs in restaurants. It's exotic and unknown, a bit like natural wine."
But the question is, does Callow think the flat white is a rip-off? Apparently not. "For £3, it's worth it - and most people don't mind, because of what it represents."
Whatever the flat white represents to you, it seems that the jury is out.