Look at your sandwich

Next time you toast a slice or open a supermarket triangle, look closely at the surface. Hundreds of little holes, which bakers call cells, stare back at you.

“On the surface of it you will see hundreds of little holes - cells, as bakers sometimes call them.”

Those cells are a clue

The holes in British sliced white are the visible trace of a huge shift in how bread gets made. The same shift shows up in South Africa and Australia, but not America or Singapore.

Not bread as it was

British sliced bread is made in a starkly different way to bread for the previous few thousand years. Some purists argue the result does not qualify as bread at all.

“some purists would go so far as arguing that it isn't actually bread”

An industrial strategy in a loaf

This was one of the biggest industrial policy interventions in modern British history. It changed the country's food chain and reshaped farming, and almost nobody noticed.

Bread is where trade starts

Grain moved between the earliest civilisations of the Fertile Crescent. Cities from Ur and Uruk to London and New York have always sat on top of a food supply chain.

No wheat, no bread

When food runs short or gets too dear, people riot. That thread runs through the French Revolution, the Arab Spring, and arguably Europe's recent cost of living squeeze.

“No wheat; no bread. That equation is etched deep into the historical record.”

Old-fashioned, actually modern

Bread reads as the ultimate homespun food, but it is a product of technology and trade. The French baguette is younger than the Eiffel Tower and the Tour de France.

Ciabatta is a 1980s invention

That rustic Italian loaf with the big holes was invented in the early 1980s, younger than the author. Its high-hydration dough needs strong modern flour, mostly imported.

“There is no making ciabattas - or many other types of modern breads - without wheat that often comes from the other side of the world.”

Not all wheat is alike

Ride a train through England and most of the wheat in the fields would never have qualified for breadmaking. It lacks what bakers have always wanted in flour.

Protein makes the loft

Gluten gives dough its stretch, and that elasticity traps the carbon dioxide of fermentation. More protein means bigger air pockets and a taller loaf.

“The more protein you have, the bigger the air pockets you can produce in your loaves.”

Thirteen per cent is hard

Wheat at 11 to 12 per cent protein is easy enough. Pushing to 13 is difficult in most of the world, and 14 or 15 takes freak luck or obsessive work.

Soggy fields, weak flour

British wheat from damp British fields runs low in protein. The dry prairies of America, Manitoba and Saskatchewan produce the high-protein grain bakers wanted.

Dependent on Canada

In the early postwar years about 65 per cent of Britain's baking wheat came from Canada, and only 5 per cent of the domestic crop was good enough for bread.

A government asks a question

After two wars in which feeding the country depended on Canadian shipments, ministers wanted a technological fix. Could Britain feed itself on its own wheat?

“Surely, the government asked, there was a technological way for Britain to be able to feed itself with its own wheat?”

Scouts sent to America

The British Baking Industries Research Association, based in a village outside the M25, sent researchers to the mills of Minneapolis and the Wonder Bread factories.

Sponge and dough

The American method ferments a flour, water and yeast sponge for around five hours, then adds flour, salt, fat and sugar for the final dough. The result slices and packs cleanly.

Beat the dough instead

Chorleywood replaced most of that fermentation with brute force: a huge mechanical mixer whips air into the dough. Hours of waiting collapsed into minutes.

“What once took hours could happen in minutes.”

It ran on British wheat

The bonus was that the process worked with lower-protein flour. A sliced white loaf could suddenly be made with as much as 85 per cent British wheat.

Coke and Pepsi of bread

Invented in 1961, the process and its machinery became a British export. India and Shanghai went Chorleywood; North America and Singapore stayed sponge-and-dough.

“They are the Coke and Pepsi of the industrial bread world.”

Round holes or elliptical

American industrial bread has round little cells. Chorleywood cells are stretched and elliptical, a fingerprint of dough churned at extraordinary speed.