How much would you pay for a slice of bread? With most white loaves containing 16 to 20 slices, the average supermarket bread costs between 3p and 9p per slice – and, if you’re really splashing out on a posh loaf, as much as 16p.
So how would you feel about paying a hefty £2.25 for a single piece of bread?
That’s the exorbitant price tag on Marks & Spencer’s ‘pan de cristal’, a traditional Spanish loaf sold as part of the store’s deli range.
Each packet – priced from £4 up to £4.50, depending on location – contains just two 40cm-long slices of plain bread, weighing around 90g each. It’s equivalent to the cost of a supermarket sandwich, but as critics have said, without the filling… or even a thin layer of butter.
The product – described by the retailer as a ‘light, crisp bread’ – is designed to be toasted and served with its crushed tomato bread topper, a 250ml puree made from tomatoes, olive oil and salt, which costs an additional £2.50.
M&S has faced calls to justify its pricing, with shoppers suggesting a ‘half piece of baguette’ can’t possibly be worth £4.50.
But the supermarket insists packs have been flying off the shelves, with sales rising by nearly a fifth after its launch in the summer.
Some of that is down to social media success. A post promoting the product went viral in July, racking up 1.6 million likes from around the world. To date, British shoppers have bought 75,000 packs.
Sarah Rainey tries out the new M&S Pan de Cristal Bread alongside the tomato and olive oil topping
And it’s far from the only pricey bakery product out there: a 2kg sourdough loaf at French bakery Poilane, in London’s Belgravia, costs £14.50 (around 73p a slice); while Gail’s 2kg sourdough will set you back £13 (65p a slice); and a Tokyo milk loaf from the trendy Happy Sky Bakery in Soho is £11.40 (95p a slice).
You can even buy a personalised boule from Harrods, estimated to cost around £17, with your initials carved into the crust (around 85p per slice).
Still, comparing the price per slice, they’re still a relative bargain compared to this M&S bread.
So what exactly is pan de cristal – the name translates in English as ‘glass bread’? And is it worth the cost?
Invented in Barcelona in 2004, with roots dating back to the 15th century, ‘glass bread’ was created by the Spanish baker Jordi Nomen, founder of the Concept-Pa bakery. Nomen was, apparently, ‘tired of hearing the myth that crumbs make you fat’, and so ‘decided to create a bread with non-existent crumb’.
Glass bread, sometimes called ‘pan de coca’ or ‘honeycomb bread’, was the result. A flat, airy loaf made from a sourdough starter and characterised by its high hydration and double fermentation method, it has a hollow, honeycomb-like interior, with large and uneven alveoli (or air pockets).
The dough inside is so sparse that, in some places, it’s transparent. The crust is thin, crisp and crunchy, giving it a fragile texture which – like glass – breaks easily.
Nomen patented it in 2009, but its popularity soon spiralled beyond Barcelona.
Each packet – priced from £4 up to £4.50, depending on location – contains just two 40cm-long slices of plain bread, weighing around 90g each
Today, glass bread is found in almost every cafe, restaurant and tapas bar in Spain, where it’s typically served with a raw, fresh tomato topping
Having lived there several years ago, I can attest to its ubiquity; indeed, in 2021, it was the best-selling bread at supermarket chain Mercadona. On Mercadona’s website, you can buy four large glass bread rolls for €1.30 (£1.15). So what makes M&S glass bread so expensive? Perhaps it’s rarity value. While there are artisan pan de cristal producers here, it’s the first High Street retailer to sell it.
For the record, even those high-end versions are cheaper than M&S. Take Yorkshire-based online deli Basco Fine Foods, which sells glass bread at £3.40 for 250g, almost £1 per 100g cheaper than Marks & Spencer’s.
Baking expert Juliet Sear adds that it’s not an easy loaf to make, due to its high hydration, the ratio of water to flour in a bread dough, which is calculated by dividing the weight of water by the weight of flour and multiplying it by 100. Breads with a tight, dense crumb (such as bagels) are typically 50 per cent hydration, while specialty breads such as ciabatta and focaccia boast hydration percentages upwards of 75. ‘The hydration can be up to 100 per cent in some pan de cristal, which makes the dough very wet, sticky and difficult to work with,’ she explains.
‘It must be hand-crafted by artisan bakers who know what they’re doing – this isn’t one for a bread novice. It’s not the sort of bread production you could mechanise.’
The bread is made in Spain, by traditional bakers, and uses two types of flour – wheat flour and malted barley flour – as well as water, yeast, salt, extra-virgin olive oil and gluten.
Shoppers can also choose versions topped with smoked cheese and tomato, or mozzarella and 12-month-matured Serrano ham (both of which cost £4).These packs contain a single slice. And they’re full of calories: per slice, the topped breads contain as many as 306 calories; while the plain is 201 calories per slice.
In comparison a standard slice of supermarket white bread contains between 30-80 calories.
‘A lot of love goes into each pan de cristal,’ an M&S insider tells me. ‘It’s a very specialist product, made to traditional specifications. It’s not an everyday white loaf you can grab off the shelf for 80p.’
A spokesman adds it uses ‘restaurant-quality ingredients’.
So does the much-hyped ‘glass bread’ live up to its viral reputation? Vamos a comer, as they say in Spain…
The bread is made in Spain, by traditional bakers, and uses two types of flour – wheat flour and malted barley flour – as well as water, yeast, salt, extra-virgin olive oil and gluten
TASTE TEST: £2.25-PER SLICE BREAD
At first glance, M&S’s pan de cristal doesn’t look appetising.
Flatter than a baguette and more uneven in shape, they look like two halves of a ciabatta that someone has squashed. Unusually for a bread product, it’s labelled ‘raw’ and must be both refrigerated and then cooked (for 15 minutes at 180C) before eating.
Once toasty and golden, however, the bread looks much more appealing.
I nibble a corner and am pleasantly surprised: inside it’s still soft and slightly chewy, while the crust is crunchy with an almost caramelised flavour.
I liberally spoon on the M&S tomato topping (each bottle is designed to top two slices of pan de cristal) and tuck in again.
Immediately, I’m transported to sunny Spain: rich, juicy Mediterranean flavours; fresh, sweet tomatoes; and a lovely crunchy base that soaks up plenty of that delicious olive oil.
It’s so good, I demolish half a slice in just eight bites. With 32 mouthfuls per packet, that’s just over 20p (dividing £4 for the bread and £2.50 for the topper) per bite – which isn’t bad for a tasty take on Spanish tapas from the comfort of my kitchen.
Next, I tuck into the topped breads. These also take 15 minutes in the oven, during which time my house fills with the moreish aroma of melted cheese.
Disappointingly, though the toppings are good – the smoked cheese especially, which comes from Navarra, and is a tangy mix of cow’s and sheep’s cheese – they’re all a little fatty, leaving the bread underneath soggy, chewy and claggy.
There’s also not much Serrano ham on the meat-topped bread; just one paltry piece.
I’m left with greasy fingers and an unpleasant oily taste in my mouth, like I’ve eaten a bad frozen pizza. Definitely not worth the 300-odd calories – or the cost.
