It wasn’t a surprise to learn that Walkers’ best-selling crisp flavour is cheese and onion. It always seems to come top in surveys, which always disappoints me, because I can’t stand it.

So it was satisfying to learn that Emma Wood, the head of Walkers’ flavour department, doesn’t like cheese and onion either. She has ‘grown to tolerate’ it.

You can’t argue with journalist Natalie Whittle’s credentials for writing this book either. 

Such is her devotion to crisps that she evaluates them individually. ‘As cashiers check banknotes, I hold each crisp up to the light and admire its soak of industrial, golden oil,’ she says.

Her favourite flavour is prawn cocktail, though she still carries a torch for the sadly departed Worcestershire sauce. 

Tastes vary geographically – for instance, Scotland has a huge preference for ‘pickled’ flavours (I’ll let you do the joke). But it’s never easy to develop new lines – Walkers had several cracks at ‘hot dog and ketchup’ before giving up.

Modern health trends have led Tyrrells to develop the salt-free (in fact everything-free) ‘Naked’ version. If you want the complete opposite, the US offers the ‘Whole Shebang’, which is every flavour mixed together. It was ­originally developed for prisoners.

Feeling posh? You could opt for ‘black ­truffle’ or ‘champagne’, or perhaps a crisp made from parsnips or carrots or beetroot.

But in the end crisps are fundamentally un-posh, hence the novelty flavours developed for special occasions, such as ‘pigs in blankets’ for Christmas, ‘baked beans’ for Comic Relief, and last year’s ‘coronation chicken’ for... er... the coronation.

The potatoes which become your crisps are first peeled with a special type of sandpaper. At least one major manufacturer refuses to accept spuds from within 500 metres of a golf course.

 This is because crows like to pick up balls, then drop them when they get bored with them. You don’t want one of those ­finding its way into your salt ’n’ vinegar. 

The seasoning is added by allowing it to fall over the crisps in what’s known as a ‘curtain’.

Crisps were popular during air raids in the Second World War because they were easy to grab as you rushed to the shelter. 

Though they weren’t always seen as merely a snack. Early packets of Smiths recommended warming them in a hot oven.

In 1950, the company’s chairman Herbert Morgan announced that ‘crisps can be... served with any meal, saving trouble and labour to the housewife’. These days the Spanish chef Ferran Adria, once of world-famous restaurant El Bulli, makes a crisp omelette.

Standards used to be higher even for delivery drivers. When Jack Lord started working with Walkers in 1982, he was measured by the company’s tailor, who made him three bespoke dark blue suits to wear on his rounds. And each Friday he received a free box of the company’s product.

These days the perk has gone, as have the suits, replaced by overalls. Understandable in modern Britain, perhaps, but Jack still misses the ‘smartness’.

In the end, this is a lightweight book (fittingly for its subject). But we still learn about Whittle’s fellow fans, such as the broadcaster David Frost, who in 1963 chose a vat of crisps as his luxury item on Desert Island Discs. 

Prince Harry’s autobiography Spare contained mentions of buying crisps in a supermarket near Kensington Palace. Might be a while before he does that again.

And, at a crisp festival (yes, really) in Ireland, Whittle observes the onion ring challenge, in which contestants have 60 seconds to cram as many of the said items onto their fingers as they can, ‘like promises of marriage to an invisible crisp betrother’. The winner, Carla, achieves an impressive score of 19.