Investigation · British Food

The Bread That Isn't

In 1961 a laboratory in Hertfordshire solved a problem nobody eating bread had asked them to solve. The solution is still in 80% of British bread today. Nobody announced what was removed in the doing of it.

Nutriofia — Updated 2025

There is bread in most British kitchens that will not change for a fortnight. Leave it on the counter. Come back in two weeks. It will be slightly stale at the edges but it will not do what bread does — what bread, being a living thing made from fermented grain, is supposed to do — which is show, within five or six days, that something in it has changed. Proper bread shows you exactly what it is. Most supermarket bread shows you exactly what has been added to it.

This is not a minor observation. It is a description of two different objects that share a name.

The Lab, and the Problem It Chose to Solve

In 1961, the British Baking Industries Research Association — a research station in Chorleywood, Hertfordshire, funded in part by the flour milling industry — solved a problem. It was not a problem that the people eating bread had identified. British wheat has lower protein content than North American wheat: it is softer, and that softness made it difficult to produce consistent, mass-produced bread at the speed that post-war Britain's industrial bakeries required.

The solution was to replace the 12 to 48 hours of bulk fermentation that real bread-making had always required with ten minutes of intense mechanical mixing — at speeds not achievable by hand, using the kind of machinery that had no place in a traditional bakery. Add extra yeast to compensate for the lost leavening time. Add ascorbic acid as a flour treatment agent to strengthen the gluten structure rapidly. Add emulsifiers — synthetic compounds — to build the soft, springy texture that fermentation would otherwise have created over time. Add fat. Flour to sliced loaf in under four hours.

The Chorleywood Bread Process worked perfectly for everyone with a stake in its working. Within a decade, it had been adopted by virtually the entire British mass-produced bread industry. Around 80% of all bread sold in the UK today is still made by this process. Nobody, in 1961, announced what had been removed in the doing of it.

What Fermentation Was Actually Doing

The 48 hours that the Chorleywood Process eliminated were not waiting time. They were doing something specific and irreplaceable, and the consequences of removing them have been playing out in British guts for sixty years.

During slow bulk fermentation, wild yeasts and lactic acid bacteria produce organic acids that begin to transform the wheat in ways that matter enormously for the person eating it. Three things above all.

Phytic acid. Wheat contains significant amounts of phytic acid — an antinutrient that binds to zinc, iron, calcium and magnesium in the gut and blocks their absorption. This is not a marginal effect. Traditional long fermentation reduces phytic acid by 50 to 90 per cent. Chorleywood bread, made in under four hours with no meaningful fermentation, retains most of it. So you eat the bread, you absorb considerably less of the minerals the label implies you are eating, and the gap between what the packaging suggests and what actually reaches the bloodstream widens silently, every day, with every slice.

FODMAPs. These are fermentable carbohydrates — present in wheat among other foods — that many people's digestive systems find difficult to process, producing bloating, pain, and changes in bowel function. Proper long-fermentation sourdough, given 24 to 48 hours, reduces FODMAPs dramatically. A CBP white loaf and a genuinely fermented sourdough are not the same digestive experience. They happen to look similar on the shelf. The explosion in diagnosed IBS and non-specific gut sensitivity across the decades that follow the near-universal adoption of CBP is not a coincidence the medical literature has missed.

Gluten. During long fermentation, enzymes begin to partially pre-digest gluten proteins before they ever reach the gut. This is why many people who believe they have gluten sensitivity find, when they try a properly made long-fermented sourdough, that they can eat it without difficulty. The gluten sensitivity epidemic of the past 40 years has often been attributed to changes in wheat varieties. But wheat has not changed as dramatically as that explanation requires. What changed — in 1961, without announcement — was the removal of the process that had been making wheat digestible for thousands of years.

The Supply Chain That Agreed

The Chorleywood Process suited everyone with a seat at the table. British farmers grew soft, low-protein wheat — not because it was nutritionally preferable, but because British soil and climate produce it, and it is what British farming had always supplied. Traditional bread-making methods struggled with this wheat and often required it to be blended with expensive imported high-protein grain from Canada or North America. CBP could use the soft domestic wheat directly. Good for the farmers. Good for the millers who bought from them.

Industrial bakeries could produce consistent bread faster, with less skilled labour, and in greater volume. The loaf lasted longer on the shelf and in the warehouse, which reduced spoilage losses for retailers and distributors. The price of bread fell. The loaf that emerged was softer, whiter, and more uniform than anything a traditional bakery could achieve at scale.

Nobody in that chain had an interest in raising a question about what had been removed. The research station that developed the process was funded in part by the milling industry. There was no consumer representative in the room. There was a press release about the triumph of British food science. It was presented as progress.

The Channel Crossing

Many people who report bloating and discomfort after eating British bread have eaten bread every day on holiday in France without any such trouble. They conclude it must be the gluten. They consider going gluten-free. They wonder whether they have become intolerant of something they have eaten all their lives.

What they encountered was not a gluten problem. A French baguette — made that morning, stale by evening, flour, water, salt and yeast, with no emulsifiers, no preservatives, no flour treatment agents — went through a genuinely different process. It is not designed to last two weeks. It doesn't need to be, because it was made today. The baker did not use the Chorleywood Process. The bread did not need to survive a distribution chain.

The French holiday effect is not placebo. It is the experience of eating something that was actually made, by someone who made it, rather than manufactured by a process that eliminated the part of the making that mattered.

Not Just White Sliced

The logic of industrial bread-making did not stop at the sliced white loaf. Traditional breads from cultures where fermentation was never the method — where bread was always made fresh and eaten the same day — have been absorbed by the same distribution system and subjected to the same industrial solutions.

A traditional chapatti is flour, water, and perhaps a little oil or ghee. It is made in minutes and eaten within hours. There is no warehouse between the kitchen and the table. It cannot survive an Indian summer, and it was never designed to. The shelf life was the same as the meal.

Sainsbury's own-brand chapattis: wheat flour, water, wholemeal wheat flour, rapeseed oil, glycerol, spirit vinegar, raising agents (diphosphates, sodium carbonates, calcium phosphates), salt, citric acid — and calcium propionate, E282. The same preservative as the Chorleywood white loaf on the shelf opposite. Elephant Atta chapattis sold in the same aisle: flour, water, palm oil, emulsifier E471, stabilisers E466 and E412, and preservatives E202 and E282.

The food is presented as culturally authentic. The ingredients list reveals the supply chain it was redesigned to survive.

The Sourdough That Isn't

When the health consequences of industrial bread began to reach wider public awareness — largely through Andrew Whitley's Bread Matters in 2006, and the debate it opened — the mass-produced bread industry noticed. Sourdough became fashionable. The demand was real. Much of the response was not.

The Real Bread Campaign, run by the charity Sustain, has consistently investigated supermarket sourdough labelling. Most of what carries the word sourdough in a supermarket, they have found, is not sourdough. These loaves use added sourdough flavouring, or very short fermentation — two to four hours rather than the minimum 24 to 48 that the science requires — or a small percentage of genuine starter alongside the same CBP emulsifiers, improvers, and preservatives as any other industrial loaf.

Labels say "sourdough style." "With sourdough." "Sourdough flavour." There is no legal definition of sourdough in the United Kingdom. A loaf can carry the word sourdough and contain zero of the fermentation time that creates what sourdough actually is. The shelf looks as though things have changed. The process, in most cases, has not.

What the Numbers Say

A real sourdough — properly fermented for 24 to 48 hours — has a glycaemic index of 48 to 54. CBP white bread has a glycaemic index of approximately 75. A published clinical trial found that white bread triggers 45% more insulin response than authentic sourdough eaten in equivalent amounts. That gap is not marginal.

Glycaemic load accounts for the portion size actually eaten. A standard serving of CBP white bread carries a glycaemic load of approximately 20. The equivalent weight of genuine sourdough carries approximately 12. Bread is present at most meals in Britain. The difference in glycaemic load, repeated at every meal, compounded over years, contributes directly to the insulin sensitivity trajectory that leads, in enough people and over enough time, to type 2 diabetes.

This is not about occasional indulgence. It is about the baseline. The bread that is presented as an ordinary, neutral, daily staple is not behaving like one.

The Salt Nobody Blames Bread For

Ask any parent where the salt in their child's diet comes from and they will say crisps. It is the obvious answer, and it is wrong.

A 25g bag of Walkers Ready Salted contains around 0.34g of salt. Set against the 2g daily maximum for a three-year-old, that single small bag accounts for roughly a fifth of the day's entire allowance — which sounds like a conviction. But when Action on Salt examined where salt in children's diets actually comes from, crisps and savoury snacks accounted for approximately 5% of total intake.

Bread and cereal products accounted for 36%.

Bread contributes seven times more salt to a British child's diet than crisps do. Not because a slice is saltier than a packet — per portion they are broadly comparable, and a 2023 Action on Salt survey found three in four bread products carry as much salt in a single slice as a bag of crisps. The difference is frequency. Nobody eats crisps at every meal. A very large number of children eat bread at every single one: toast at breakfast, sandwiches at lunch, a roll with dinner. Three or four slices a day, before anything is put on top of them.

And this is the mechanism the whole article has been describing, appearing in a different nutrient. The crisps announce themselves. A child knows a bag of crisps is a treat; a parent knows they handed one over, and can decide whether to hand over another. The transaction is visible and it is therefore governable.

The bread announces nothing. It is filed under sensible. It is the thing you put the treat on top of. It arrives at every meal without a decision being made about it, which means the salt arrives without a decision being made about it either — and it is doing seven times the work.

What To Do

Three things are available immediately, without expense, and without waiting for a regulator to act.

Read the ingredients list on the bread you currently buy. If it contains emulsifiers, flour treatment agents, or a preservative — if the list extends beyond flour, water, salt, and yeast — the fermentation was not doing the work it should have been, and something has been added to compensate. The additives are not enhancements. They are substitutes for the process that was removed.

Find a bakery that uses real fermentation. The Real Bread Campaign finder above will show you what is near you. Artisan bakers are not a niche lifestyle choice. They are commercial businesses — with staff, with costs, with every pressure that any business faces — who have concluded that the Chorleywood shortcut produces something that should not be called bread, and have declined to use it. Their bread is more expensive, and it goes stale faster. Both of those things are features, not problems.

Perform the mould test. Leave whatever you currently buy on the counter and see what happens in a week. A loaf that shows no change after seven days was engineered to survive distribution, not to feed you. The engineering required an agricultural fungicide to be listed among the ingredients. It is worth knowing this, and worth deciding whether you want it.