In May, the UK government launched its “Prepare” emergency awareness campaign, ominously encouraging people to stock up on things such as bottled water, a wind-up radio and non-perishable foodstuffs. I’ve collected a few cans of soup but, more successfully, I’ve quietly been stockpiling the Co-op’s sea salt and chardonnay wine vinegar crisps (in the big bags), just in case. Like millions of British people, when I say I love crisps, I really mean it.

Crisps are the ideal survival product, sealed and salted, but a great packet can also function as a private restaurant where you dine alone, crisp by crisp, intensely scrutinising the crunch, flavour and execution, like a Michelin inspector of snacks. They are as transporting as they are comforting – and unsurprisingly, they had a good pandemic, with Britons buying £441m more bagged snacks in 2020 than they did in 2019. They even helped morale during the blitz. At Smith’s Crisps AGM in 1941, chairman Sir Herbert E Morgan noted that Londoners were taking the brand’s crisps down to air raid shelters: “As in times of peace our crisps have been a standby, and an always reliable friend – they are additionally so these days,” he told shareholders.

It’s rational that we should seek out our “reliable friend” in times of need or uncertainty. Salt alone does uplifting things to the brain, scientists have suggested, based on studies of how it is cognitively gratifying to small mammals, at least. But crisps also reveal more complicated affections, including ideas of what Britain notices and likes about its own character.

In the 1950s, food scientists began to finesse the art of imitative flavours in compounds, and since then crisps have been able to carry out an uncannily accurate and sometimes waspish national conversation. It shows up on shop shelves in special editions such as Walkers coronation chicken, in honour of King Charles, or Morrisons’ ’nduja, as a vogueish nod to Shoreditch’s favourite pizza topping, or Kettle Chips sea salt and crushed black peppercorns, as a hat tip to the Waitrose middle classes.

The UK is perhaps the only nation to insert historical footnotes and social sarcasm into foil packets, while also imitating fads and trends steaming out of restaurant kitchens. This has been going on for decades, with 1990s crisps becoming a discussion of class via the introduction of “posh” crisps in fancy flavours and kettle/hand-cooked techniques. It’s common to see caricatures of British social types as part of visual branding. And now in an age where we’re fed tidbits of other people’s social status online, crisps can function as accessories. Torres are for today’s east London set what Marlboro Lights were to Soho late nights in the 1990s.

Our national snack obsession mostly involves a handful of unbeatable flavours, albeit spun off into eye-catching variations (think Kent Crisps’ oyster and vinegar). PepsiCo’s Walkers, for example, runs on classics that an entire nation never tires of, in situations that also have a timeless grip. Ready salted (the crisp sandwich); salt and vinegar (the pub); cheese and onion (the antisocial train journey); prawn cocktail (childhood); something beefy (lunch break boost). The latest wedding trend, meanwhile, is for nostalgic “crisp walls” that pin retro packets to a board, while florists are even offering “crisp bouquets” as a romantic alternative to red roses. Anya Hindmarch has a crisp-mould handbag, as does Balenciaga. Sales of 1990s favourites have also recently rocketed, as “Britishcore” trends on TikTok.

As for how we came to be so intergenerationally bewitched by sliced, fried and salted potato slices, we’re only just catching up with what the industrial, social and technological ride of the past half-century in particular has meant for our beloved snack.

There are a few dates this story could rewind to. A purist would trek back to the so-called “furnaces of creation” in Latin America, where wild potatoes were collected and spread to Europe from the 16th century onwards. Every crisp you buy owes something to the amazing fecundity of the Andes.

Closer to home, there is Cricklewood in 1919, where Frank Smith started his crisp factory behind a pub, or 1954, when meat rationing ended and cheese and onion powdered flavouring was born in Tayto’s rented rooms on O’Rahilly Parade in Dublin. An Edinburgh bakery in 1947, and a Leicester butcher in 1948, also saw the beginnings of Golden Wonder and Walker’s, respectively. Dallas had a big year in 1961, as the Frito-Lay merger primed what began as two kitchen-table startups to become a global snack empire. All of these developments were important to the progress of crisps, and are part of a much longer chronicle.

But when thinking about how Britain got deeply attached to crisps, one of the most telling phases came in the 1980s, as the country emerged from a decade of hard times. Food price inflation in the 1970s was “dizzying” as Delia Smith herself put it – rising 300% in 10 years. Food started to fortify snobbery around what you could afford being somehow indicative of who you were.

Crisps had flown under the radar of such considerations until this point. From the 1920s until the 1970s, their biggest marketplace was the pub and hotel trades, functioning like wallpaper, in the background, designed to accompany other things – beer, picnics, cocktail parties, school lunch boxes. In 1961, 65% of crisps’ market turnover came from the licensed trade, according to the Journal of Industrial Economics. By 1969, that figure had dropped to 25%. Supermarkets started to grow and other things were changing in British society too. Women were gaining better educational chances, and working more. Housing now included more flats, and an increasing portion of the affluent classes cooked for themselves. Crisps were marketed into this niche: tasty, but also time-saving.

When Denis Healey’s plans for value added tax enshrined crisps in the “luxury” taxable food category in 1974, the unease was palpable on both sides of the dispatch box. During a late-night debate in April 1974, Michael Shersby, Conservative MP for Uxbridge, asked the Commons: “What about potato crisps, which are to bear the full rate of VAT? Many of my constituents find potato crisps a helpful, useful and convenient part of their diet. They eat them with salads and with other nutritious foods, but they will go up in price by 10%.”

MPs also worried about what the rise would mean for small businesses, since crisps were seen as a plucky entrepreneurial sector, with regional competitors such as Lothian or Highlander playing into local loyalties. In the event, crisps managed to weather the addition of VAT. The product itself had improved, thanks to the arrival of continuous fryers from the US, and form-fill-seal machinery that clamped down the crisps’ freshness with heat-sealing jaws. One crisp entrepreneur I spoke to, John Mudd, who began Real Crisps in south Wales, remembered children in the 1950s crying out during showings of westerns at the cinema in Cardiff, upset that the crisps they’d bought from the tuckshop had gone stale. If crisps had become more expensive by the 1970s, they were at least a more reliable purchase. This, the Journal of Industrial Economics noted in 1974, helped to embed them as a repeat feature of British grocery baskets.

By 1984 alone, Britons spent £805m on crisps and snacks, according to Mintel research, a figure that would pass £1bn by the end of the decade. Walkers went on a hiring spree to get enough drivers to deliver crisps to the nation that had an evermore bottomless appetite for them, backed by TV ads and promises of wild new shapes and flavours. For a spell, Walkers Crisps truck drivers really looked the part. In dark blue Burtons suits and Walkers-motif ties, they criss-crossed sales routes from Leicester layered up in weatherproof coats, thermal underwear and thick boots, all of which came with the job. The suits were made to measure by a tailor who called into the factory – and Walkers paid for dry cleaning. On Fridays, hauliers could take home a box of free crisps each, if they wanted. The only thing that wasn’t included in the deal was socks.

By the end of the 1980s, Walkers had been bought by PepsiCo, which had the keys to the “Pentagon of snacks”, the Frito-Lay headquarters in Dallas. Britain, which always liked to think of itself as the global crisp connoisseur, now lived in the expertise shadow of the Americans. PepsiCo did most things differently and a lot of stuff better, not least the art of marketing. When it came to launching Doritos in the UK in the 1990s, the Americans were unhappy with the British tortilla chip, so sent a team from Leicester to Modesto in California and beyond, to learn the American art of milling, toasting and frying. They slaved for months on return to the Coventry factory to get the British Dorito up to scratch.

Walkers’ livery is less visible on today’s roads – contractors mostly deliver in their own vehicles, and the bespoke suits were replaced by overalls in the 1990s. The free box of crisps was also stopped – instead, drivers could fill a bin bag for a fiver.

You can love crisps to the ends of the earth, but there will still be one you haven’t tried. If I mentioned to anyone that I was writing a book about crisps, I knew there would be immediate quizzing. Will you be including German paprika chips? What about Highlander tomato? What do you think of Torres fried egg? Are Pringles really crisps? (Yes, according to lengthy tax wranglings pursued by HMRC.) I’ve yet to come across someone without at least two or three strong opinions about crisps. Larry Bush, who was part of PepsiCo’s British tortilla team (and now runs a wildlife park outside Bristol), told me: “You could put people into crisp tribes depending on where you grew up. Crisps are almost like a member of the family.”

This is curiously asymmetrical with the industry itself, which is tight-lipped and extremely competitive. It is cut-throat, rewarding bulk orders and purchasing power. This has been the case for almost 100 years – when Smith’s Crisps was the undisputed market leader in the 1930s, for example, its smaller competitors fell away without Smith’s even trying. It had got to market first a decade before, bagging the best sales routes and supplier contracts, and could not be beaten on wholesale price. Today, Kent Crisps stands out for being a rare example of an indie outfit, with a sole director, Laura Bounds, who told me that when she has bid for airline or cruise ship contracts, she has found “big crisp” offering its product at a loss, just to gain market share.

Every year as a nation we eat the weight of one of the world’s largest container ships in crisp form (about 186,000 tonnes), which makes the game worth fighting for. But, in truth, it has been a struggle to keep a product consistent even as the world changes at speed; and as we expand our appetites to include “healthy” crisp variants, in baked, “popped” and protein-based form, it will be harder keep the affair going exactly as it was.

Crisps, after our Brexit divorce, appear to be having more fun than ever in Europe. Belgian brand Superbon, for example, is spicing up tradition with ideas such yellow paprika, while Breton makers Les Brets is giving Lay’s a run for its money with bistro-worthy flavours including rotisserie chicken. Could it be that we told ourselves a lie all along, that other countries love crisps just as much as we do? We keep eating crisps in Britain not because we are the best at making them, or even the hungriest (that’s Japan and the US), but because we’re still enjoying the debates. Are “high” crisps better than “low” ones? Is it true that the underside of Pringles is the best side to eat tongue-down first, coated with more flavour? Who does the best salt and vinegar? It’s unresolvable, which is part of the fun. We love crisps as much as we’re fond of the madness and unevenness of Britain itself.

Crunch by Natalie Whittle (Faber, £18.99). To support the Guardian and Observer, order your copy at guardianbookshop.com. Delivery charges may apply

Chefs and crisps

How crisps, and crisp-adjacent snacks, are making it to menus

Handmade
Painstakingly handmade at, for example, Manchester’s Medlock Canteen, Birmingham’s Riverine Rabbit or José Pizarro’s Lolo (where they are topped tapas-style with escabeche-pickled mussels), high-end restaurant crisps enjoy cult status. The hot-spiced crisps at Borough Market’s Agora, flavoured with nine seasonings including kombu dashi, vinegar powder and cumin, are, says one admirer, “probably the best crisps I’ve ever had”.

Crunchy
Famously used to garnish an omelette in season 2 of The Bear, crisps can also be a useful ingredient, adding crunch and specific, intense flavours. At Abersoch’s Dining Room, owner Si Toft sometimes conjures “a massive flavour hit” in breadcrumbed fish by first dredging it in a 50:50 mix of seasoned flour and blitzed scampi fries. “You mess, don’t you? We’ve all done it,” says Toft, of this discovery. He has also dressed slivers of ox tongue with pickled onion Monster Munch crumb: “Chefs’ brains work in a weird way. And it looks fun on the menu.”

Doritos!
Tortilla chips are particularly useful. For “extra filthy, very crunchy” results, Sam Evans, one half of Welsh chefs Hang Fire Kitchen, coats buttermilk fried chicken in crushed tangy cheese Doritos. Chef Meriel Armitage, owner of London’s Club Mexicana restaurants, uses crouton-sized pieces of cool original Doritos mixed through salads – for texture and to “soak up all the dressing”.

Pudding?
Nina Matsunaga, chef at Sedbergh’s Black Bull, recommends cool original Doritos or ready salted crisps broken atop chocolate mousse, to enhance its depth of flavour: “Trust me. Like pretzels, it’s very pleasing.” Tony Naylor