Food trends move at incredible speed – but even so, the rise of the smash burger has been remarkable. Less than a year ago, this style – essentially, burgers rendered as wider, flatter, crispier patties, for maximum flavour – was a fairly niche concern. An enthusiastic hardcore, including Newcastle’s Meat: Stack, Danny’s Burgers in Bristol and Slap & Pickle’s mainly northern outlets, had been serving “smashed” burgers for some years. In October 2022, Honest Burgers introduced a few smash-style burgers to its menu, too. But beyond burger geeks, there was little excitement about the form.

Last winter, that all changed. In Soho, a new takeaway called Supernova generated queues that led GQ magazine to declare: “The smash burger has officially eaten London.” Further London smash burger venues soon followed, including Supra Burger, SMSH BN and Temper Burger. Then in April, Waitrose gave the format national exposure when it launched its own smash burger with bone marrow. Aldi launched its smash burger in May. And this autumn, Honest Burgers, which has sold well over a million smash burgers since adding them to its menu, will open a dedicated smash burger spin-off in London.

A decade on from the last great wave of burger excitement, the smash burger marks a clear break with that era’s “dude food” excesses and towering, monster burgers. And it’s not just a British phenomenon. When the writer, film-maker and foremost historian of US burger culture George Motz opened his retro-modern diner Hamburger America in New York last November, he did so with a notably modest menu. Dispenser of what Bon Appétit magazine called “NYC’s most hyped burgers”, Hamburger America serves just two regular burgers: both smashed patties. Motz describes these as “primary-source burgers that go back to the dawn of the hamburger”.

Still a little confused by the hype? Here’s a quick primer on the concept.

How do you smash a burger – and why?

Instead of grilling pre-formed burger patties, balls of mince are placed on a furiously hot flat-plate grill and, to produce a pronounced sear, firmly smashed or pressed into thinner, wider-diameter patties, using a metal burger press or heavy spatula. According to one of the smash burger’s many origin stories, the original implement was a can of beans.

Historically, smashing was the quick, efficient and unremarkable way burgers were cooked in US diners. If it had dwindled as a skill, the 2010s rise of cut-above US chains such as Shake Shack and Smashburger did much to revive a slow-burning interest in the style among burger aficionados.

Specific techniques and patty weights vary. Some kitchens produce very thin patties that stack like crepes. Others smash relatively standard 150g burgers. But the aim is always the same: to create a wider surface area in contact with the grill, increasing the extent of the Maillard reaction on the burger, which creates intense, savoury flavours on the patty’s exterior.

Smash burgers should offer differentiated flavours and textures across their span, which, says David Lagonell, Temper Burger’s chef-director, “you don’t get with a normal patty”. The burger’s central section should be plumper, offering clear meatiness and juiciness, but its lacier, thinning edges will, ideally, develop lots of crusty, crunchy bits. “There is a skill involved in getting that right,” says James Tabor, co-founder of Slap & Pickle. Uniformly ultra-thin, crispy patties may look great on Instagram and TikTok, says Tabor, but “if it doesn’t taste of meat, it’s disappointing”.

What makes an exceptional smash burger?

Better beef, obviously. Smashing emerged during the Great Depression as a cheap way of turning “average-quality ground beef into something charred, caramelised, and deeply flavourful”, to quote the food website Eater. But the best smash burger protagonists are fastidious about sourcing.

Slap & Pickle’s mince comes from butchers Swaledale, which supplies some of Britain’s best chefs. Temper Burger, a spin-off from London’s five Temper barbecue restaurants, uses beef from a single Yorkshire farm, butchered in-house. “We butcher the whole animal and utilise every single bit,” says Lagonell.

Smash burger mince needs a roughly 30:70 fat-to-lean ratio, and will be preferably minced from whole cuts of meat so the muscle fibres and fat are attached in a natural way. If kitchens buy lean mince and add fat to the mix, says Tabor, “you can really tell. The fat is not correctly distributed. It makes this hole-y looking shred of a patty.”

On the grill, retaining that flavoursome fat is key. A smashed patty should cook so quickly (in 90 to 180 seconds), there isn’t time for too much fat to render away or moisture to be driven out. By design, it should stay juicy. The advice from Honest Burgers’ head of food, Adam Layton, is to smash once, and early: “If you leave it until the fat starts to render, you’re pressing all the fat out – all the fun. Smash it, flip it and don’t smash the second time, because that’s when the fat’s in its liquid form. You can kill a burger that way.”

Can I get pulled pork, onion rings and a waffle on that?

Probably not. True, some smash burger outlets serve four-patty stacks and such. But the trend is towards lighter, compact burgers that, rather than having to be wrestled into submission, function like sandwiches. Leyli Homayoonfar, chef-owner at Mexican street food brand Bab Haus, which sometimes serves burgers from its Caerphilly HQ, appreciates that change: “I want something neat that I can hold in two hands. Little mess. Clean, you know?”

Rather than outrageous toppings and gimmicky serves, the focus is on letting the meat’s flavour shine, classy sauces (brown butter mustard mayo at Honest Burgers; Temper’s has chipotle sour cream) and confident simplicity. Layton loves the cheeseburger at New York’s 7th Street Burger: “It’s cheese, pickles, special sauce, grilled onions. For me, that’s the platonic ideal.”

I’m sold. But what will it cost?

A good smash burger with fries is usually about £12 to £15; competitive in premium burger terms and compared with most main courses. Singles are cheaper, obviously (in London, Honest Burgers’ 100g patty burger with fries is £9.75), but with most operators serving double-patty burgers as standard, the quantity of beef is generally similar to that (about 120g to 170g), served in a regular, single-patty burger.

In terms of keeping prices keen, smash burgers have an edge, however, in that, even by burger standards, they are a very efficient product. You do not need a large team of highly trained chefs: smash burgers cook at least 50% quicker than regular patties, are easier to cook accurately, and are often simpler stylistically, with fewer components to assemble.

At a time of spiralling costs and squeezed consumer spending, the smash burger is that hospitality holy grail: a fun, familiar dish that restaurants can produce quickly, consistently and cost-effectively. “That’s where the economy will be for us,” says Layton. “Opening more restaurants where we can service more customers more quickly.”

Is there a meat-free option?

Presciently, Beyond Meat launched a “ready to smash” version of its plant-based patties last year, and London’s vegan Neat restaurants now serve a smash burger. Made with fermented mushrooms, chef Neil Rankin’s vegan Symplicity burger has a growing rep among experts (“Like the veggie equivalent of aged meat,” as one puts it). Its consistency lends itself to being smashed thin and developing a crispy sear, and Symplicity is about to launch a specific smash burger line into restaurants.

Beyond the smashing, what’s next in burgers?

More than 1,500 years after the Romans were eating isicia omentata (richly spiced minced meat and pine nut patties), you might think the burger is exhausted, creatively. But new ideas keep coming.

Old ideas, too. “There’s a lot of raiding the past,” says Layton, with the US increasingly interested in its regional burger variations. The other regular burger at Motz’s Hamburger America is an Oklahoma-style patty, in which a wad of finely sliced onion is smashed into the patty on the grill. In the 1920s, the onion was used to stretch beef further in hard times; now, it intensifies flavour. “You get caramelised, frazzled onion shards inside the burger,” says Layton, who is also fascinated by the Wisconsin burger, served with a scoop of butter on top, and Dyer’s Burgers in Memphis, where the patties are deep-fried: “An amazing place.” The latter is a concept that may send you – or those boiling up #waterburgers on TikTok – running to the relatively healthy sanctuary of Connecticut, where burgers are often steam-cooked.

One California technique you may have seen in the UK (popularly credited to cult burger chain In-N-Out) is the mustard-fried smash patty. One side of the burger is coated in mustard before grilling which, says Layton, “cooks out the mustard’s vinegary acidity and just leaves a toasty, smoky extra layer of savouriness on the burger’s crust”. In May, Honest Burgers’ mustard-fried California burger was its bestselling special ever.

Given how central beef is to burgers, its sourcing may well become even more specialised. For example, Bab Haus uses ex-dairy beef in its burgers; mince from older, retired dairy cattle. “It’s a deeper, meatier beefy flavour because it’s had longer to graze and mature. It’s naturally aged,” says Homayoonfar.

Not that beef is the only option. Consumer research and burger vendors will tell you that chicken is the coming protein among younger diners. Crispy fried chicken burgers are increasingly essential on menus. “Annoyingly, it sells really well,” jokes Lagonell, talking about Temper Burger’s chicken option.

For true food geeks, every element of the burger is worthy of analysis. Soft demi-brioche buns (perhaps briefly steamed, to make them more doughy and malleable) have become standard in the UK. But in the US, potato rolls (the Martin’s brand, particularly) and milk rolls dominate the burger scene. In the search for marginal gains, these styles may begin to make inroads in the UK.

Or could the bun go altogether? You may be familiar with restaurants wrapping burgers in lettuce leaves, but the viral popularity of In-N-Out’s onion Flying Dutchman – a double cheeseburger sandwiched between two large slices of grilled onion – suggests the burger world has barely scratched the surface of its potentially bunless, lower-carb future.

Elsewhere, burger mince is increasingly being used as an ingredient: on top-loaded fries, on pizzas, in spring rolls, or crumbled into tacos and burritos. Chef and food writer Brad Prose created a TikTok sensation last year with a mashup recipe that involves smashing a burger using a tortilla, to create a smash burger taco.

If you still want to get a bit messy with your burger, Slap & Pickle’s new duos of wet and dry dips, such as gravy and pork scratchings or cheese sauce and smoky bacon crumb, make intriguing sense. That could have legs.

But I love a thicker burger patty. Is this the end?

According to analysts Lumina Intelligence, burgers are the bestselling main dish in UK high street restaurants. Given that ubiquity, all tastes remain catered for. Many revered burger makers, such as London’s Bleecker and Mother Flipper, offer patties and double-stacked burgers of varying thicknesses, leaving the smashing to others.

Happily, this is not a battle you need take sides in. You can flip between smashed and the meatier heft of bigger burgers at will. You have options.

Hospitality is a volatile business. But the closest you will get to a sure bet is that the burger multiverse will continue to expand, offering patties in numerous styles. “Burgers will always be around,” says Layton. Who would argue with that?