Chorleywood Bread Process vs craft bulk-fermentation: how Britain's two bread traditions diverged and what each demands from flour and improvers

Two traditions, one shelf

Walk into any British supermarket and you can hold both of Britain's bread traditions in your two hands. In one hand: a soft, square, thin-crusted white sliced loaf with a crumb so even it looks extruded. In the other: a floured, thick-crusted craft bloomer or tin loaf with an open, irregular crumb. They share four ingredients — flour, water, yeast, salt — but almost nothing else. One is the product of the Chorleywood Bread Process (CBP), the method behind roughly eight in ten UK loaves. The other is craft bulk-fermentation, the older tradition that now accounts for around 3% of the market but is growing fast under the "Real Bread" banner. (See image img-b7cw-01.)

For a British baker this is not an academic distinction. It decides which flour you buy, whether you need a bread improver at all, what fat does in your dough, how much water and yeast you use, how long your process takes, and how your loaf is allowed to be labelled. This dossier walks through the divergence and, crucially, what each route demands from your flour and improvers — with the exact Domson catalogue products to order for each.

A short history: 1961 and the Chorleywood revolution

The CBP was developed in 1961 at the British Baking Industries Research Association (BBIRA) in Chorleywood, Hertfordshire — the work is credited to Bill Collins, George Elton and Norman Chamberlain. Post-war Britain wanted plentiful, cheap, soft, long-keeping sliced bread, and it wanted to bake it from the lower-protein wheat that grows well in the British climate rather than relying on expensive strong imported wheat.

Their insight was to replace time with energy. Traditional bulk fermentation develops gluten and flavour over several hours; Chorleywood develops the gluten in one intense burst of high-speed mechanical mixing to a fixed work input of about 11 Wh/kg of dough (12–13 Wh/kg or more for stronger flours), delivered in roughly 3 minutes. Add a fast-acting oxidant (originally including potassium bromate; today ascorbic acid), a small proportion of hard fat, extra water and extra yeast, and you get a fully developed dough that goes straight from mixer to divider with no bulk fermentation at all — a so-called "no-time dough". The whole run, flour to sliced and packaged loaf, takes under about four hours.

The economics were transformational. Because intense mixing does the work that fermentation used to do, CBP can be run on lower-protein home-grown wheat: according to Campden BRI (the institute that grew out of the process's birthplace, and the single source for this specific figure), around 80% of the wheat used for UK bread is now UK-grown, against about 30% before CBP. The Federation of Bakers puts today's market at roughly 85% plant bakeries, 12% in-store (supermarket) bakeries and 3% craft bakers, with over 13 million loaves and bakery packs sold every day. Most of that plant bread is Chorleywood.

How the two processes actually differ

The single biggest difference is where dough development comes from: a machine (CBP) or the clock (craft). Everything else follows from that. (See the process comparison img-b7cw-02 and the energy-vs-time trade-off img-b7cw-03; the full attribute table is in data.json → cmp-process.)

• Chorleywood / no-time dough. Weigh flour, water, yeast, salt, improver and fat; mix intensely to target work input in ~3 minutes; divide immediately; mould; final prove ~45–55 minutes; bake; cool; slice. Fine even crumb, thin soft crust, mild flavour, stays soft for days.
• Craft bulk fermentation. Mix to a smooth dough; bulk ferment 2–3 hours (or hold a sponge for several hours) with a knock-back or two; divide; bench rest; shape; final prove; bake with steam. Open irregular crumb, thicker crust, fuller flavour. This is the stage CBP removes, and it is exactly what our Pillar A dossier A5-bulk-fermentation covers in depth; the mixing side is in A5-dough-mixing-methods (which compares straight dough, sponge-and-dough, Chorleywood and activated dough development directly).

CBP trades craft skill and time for capital and additives; craft trades capital for time and skill. Neither is "better" in the abstract — they are engineered for different products and different price points. The scaling questions between them are the subject of A5-scaling-artisan-to-industrial.

What each route demands from flour, improvers and fat

This is the heart of the matter for a working baker, and it is where the Domson catalogue earns its place. (Diagram of a UK improver's contents: img-b7cw-04; why CBP needs a high-melt fat: img-b7cw-06.)

Flour: strength and protein

Craft bulk-fermentation rewards a strong, well-matured flour (around 12–13% protein) because the long ferment relies on an extensible, resilient gluten network — see A1-protein-gluten-and-strength and the parameters (ash, protein, falling number) in A1-key-quality-parameters. CBP's whole reason for existing is that it will make an acceptable loaf from weaker, lower-protein flour, because the mixer forces gluten development that fermentation would otherwise coax out slowly.

A dependable base for either route is a strong wheat bread flour such as Bread Flour Type 750 (prod_01KJABDDEM0JP5FW52ZH8N2912). Its first-party datasheet specifies ash ≤0.82%, falling number ≥220 s, wet gluten ≥26% and protein around 11.6 g/100 g — and, tellingly for this article, it carries the UK statutory fortification premix (see next section). For choosing between flours by application, our A1-wheat-flour-types-by-application and the British-specific B7-flour-landscape go deeper.

Vital wheat gluten: reinforcing weak flour for the mixer

When flour is too weak for the crumb structure you need — or when you are adding fibre, seeds or wholemeal that dilute the gluten — you add vital wheat gluten (VWG). This is the classic lever for making lower-protein flour behave under intense CBP mixing. BeneoPro VWG 75 (prod_01KJABDKPPNK973N55VC42HA5E) is min 75% protein (N×5.7) with a water-binding capacity of ~140–170 g per 100 g — dosed typically at a few percent on flour. The dedicated dossier is A3-vital-wheat-gluten.

The improver: an oxidant plus an emulsifier (and often enzymes)

A bulk-fermented craft loaf may use no improver at all — time does the conditioning. A CBP loaf almost always uses one, because the process depends on a fast-acting oxidant to build gluten strength in seconds rather than hours. The archetypal UK product is Puratos S500 (prod_01KJABERPBY3ZTMX272DYEAXTE), and its spec sheet is a perfect anatomy lesson in what a British bread improver is:

• Ascorbic acid (E300) at 0.9–1.1% — the fast oxidant (vitamin C). This is the modern, permitted replacement for the banned oxidants (below). Full theory in A3-ascorbic-acid-oxidants-reductants.
• DATEM (E472e) — a dough-strengthening emulsifier. See A3-emulsifiers-in-bread.
• Calcium sulphate (E516) anti-caking agent, and rapeseed oil.
• A wheat-flour carrier that itself lists the statutory fortificants (calcium carbonate, iron, nicotinamide, thiamine).
• Country of origin: GB. Dose: up to 2% on flour weight.

That is the general-purpose improver behind a great deal of British sandwich bread. For the underlying "what and why", read A3-what-is-a-bread-improver; for the enzyme side (amylases, xylanases that give softness and shelf life), A3-enzymes-in-bread and A5-bread-improvers-enzymes; and if your positioning is cleaner, the enzyme-only route is covered in A3-clean-label-improvers. To pick a dose and product for a given job, use A3-improver-selection-guide.

A note on banned oxidants (food-safety / regulatory — flagged for review). Two agents that older recipes may still name are illegal in British bread. Potassium bromate was prohibited as a flour improver from 1 April 1990 — by SI 1990/399 in England and Wales, with a parallel instrument (SI 1990/395) taking effect the same day in Scotland, so the ban is UK-wide. It is an IARC Group 2B possible carcinogen and is still permitted in the US. Azodicarbonamide (E927a) is likewise banned in the UK and EU (it can generate semicarbazide/urethane on baking) but remains permitted in the US. If you inherit a formula quoting either, replace the oxidation function with ascorbic acid, which is what modern improvers use. (data.json → cmp-oxidants.)

Fat: why CBP needs a hard fat

Craft loaves often use no fat, or a little butter for softness. CBP specifies a small proportion of hard fat for a structural reason: the intense mixing creates an enormous number of tiny gas nuclei, and a fat that stays solid at proof and early-oven temperatures coats and stabilises those fine cells to give the characteristic close, even crumb (img-b7cw-06). A fat's slip melting point is the number that matters here. Cardowan's Coronet NHAV HR high-ratio shortening (prod_01KJABEKDQTKT797ZVE71H15QN), made in Glasgow, has a slip melting point of 44.0°C — well above proof temperature — with a distilled monoglyceride emulsifier (E471) and ~12% incorporated air. That is exactly the high-melt profile the process was designed around. The science of melting point, plasticity and shortening is in A4-fat-types-and-selection.

Yeast and malt

CBP uses more yeast than a bulk-fermented dough, because there is no fermentation time for the population to grow — the gas must come fast. Lesaffre Benevia fresh yeast (prod_01KJABE3VMMQV1XJ7REDH64XKM) is standard: pure Saccharomyces cerevisiae, dry matter >29%, fermentative activity 125 ± 10 ml CO₂. Yeast formats and dosing are compared in A2-yeast-types-comparison.

Both routes can use diastatic malt for colour, flavour and fermentable sugars — and Britain has a proud maltster tradition. EDME's HDA White Bread Malt Flour (prod_01KJABEKDMPPEBDG53S73R4AWT), milled in Mistley, Essex, is 100% malted barley with a diastatic power of 165–220 °IOB (target 180) — meaning it is enzyme-active and supplies amylase, sugars and that malty crust note. Non-diastatic and diastatic malt selection is covered in A3-malt-and-malt-extracts, and the British malt story in B7-malted-grain-baking.

The Bread and Flour Regulations: the home-market rulebook

This is the one section a British baker cannot afford to get wrong. Regardless of process, all non-wholemeal wheat flour milled in the UK must be fortified under the Bread and Flour Regulations 1998. The statutory minima, per 100 g of flour, are (img-b7cw-05; data.json → cmp-fortification):

• Calcium (as calcium carbonate/chalk): 235–390 mg
• Iron: ≥ 1.65 mg
• Thiamin (Vitamin B1): ≥ 0.24 mg
• Niacin (Vitamin B3) (nicotinic acid or nicotinamide): ≥ 1.60 mg

You do not have to take a regulator's word for it — you can read those exact numbers off a bag. The Bread Flour Type 750 datasheet declares a "micronutrient premix" of calcium carbonate 235–390 mg, iron ≥1.65 mg, thiamin ≥0.24 mg and nicotinic acid ≥1.60 mg per 100 g — the statutory figures, line for line. Wholemeal flour is exempt, because retained bran and germ are natural sources of these nutrients (see A1-wholemeal-and-high-extraction).

New for the home market (food-safety / regulatory — flagged for review): folic acid. The Bread and Flour (Amendment) (England) Regulations 2024 (SI 2024/1162) add mandatory folic acid at 250 micrograms per 100 g of non-wholemeal wheat flour, with full compliance required by 13 December 2026. Wholemeal flour and small mills producing under 500 tonnes a year are exempt. The public- health aim is to help prevent around 200 neural-tube-defect-affected pregnancies each year. For most bakers this changes nothing operationally — your miller adds it — but it changes your labelling and is worth knowing when a customer asks.

The Real Bread Campaign takes a pointed view of all this, arguing the word "fortification" flatters a practice that only restores "five lost micronutrients" stripped out by roller milling. You do not have to share their politics to use their factual summaries, which are accurate on what is added and to what.

Sourdough, sourfaux and the Real Bread revival

Here is a fact that surprises many bakers: UK law contains no legal definition of "bread" or "sourdough". Anything can be called bread, and — until recently — anything vaguely tangy could be called sourdough. On 31 January 2023 the Association of Bakery Ingredient Manufacturers (ABIM), endorsed by the UK Association of Producers of Yeast, the Federation of Bakers and the Craft Bakers Association, published a voluntary "UK Baking Industry Code of Practice for the Labelling of Sourdough Bread and Rolls". Read it carefully, because it is tiered (labelling / regulatory — flagged for review): its top "Sourdough" tier permits only a small amount of baker's yeast (up to about 0.2%) and no additives beyond the mandatory flour fortificants, whereas its lower "...with sourdough" and "sourdough flavour" tiers do allow baker's yeast as the principal leaven together with permitted additives. So the word "sourdough" alone does not license yeast and additives — but the qualified lower tiers effectively let a heavily yeasted, additive-containing loaf carry "sourdough" somewhere on its label, which is the crux of the dispute below.

The Real Bread Campaign rejects this. Its definition of genuine sourdough is bread leavened only by a live sourdough starter culture and made without additives; it calls anything else "sourfaux" and campaigns for a legally binding "Honest Crust Act". (See img-b7cw-07.) For a craft baker this is a commercial opportunity as much as a semantic dispute: a genuinely starter-leavened, additive-free loaf is a premium product with a story, and the label "Real Bread" means "made without any processing aids or other additives". The microbiology behind it is in A2-sourdough-cultures-science and A5-sourdough-technology; the British revival, the code and positioning are the subject of the sibling dossier B7-sourdough-real-bread.

Choosing your route — and buying for it

There is no single right answer; there is a right answer for a given product (img-b7cw-09; the three worked formulas are in data.json → formula_cards).

• High-volume sliced sandwich bread, soft rolls, burger buns → Chorleywood / no-time dough. Strong bread flour (Type 750), an all-purpose improver (S500-type, ascorbic + DATEM) at up to 2%, a high-melt shortening at 1–2%, extra yeast (~2.5–3%), and vital wheat gluten if your flour is weak. See formula fc-cbp-white-tin.
• Premium craft tin loaves and bloomers → bulk fermentation or sponge-and-dough. Strong, well-matured flour, 1–1.5% yeast, 2–3 hours bulk ferment, little or no improver, optional 0.2–0.5% diastatic malt for colour. See fc-craft-bulk-tin; preferments in A2-preferments-poolish-biga-sponge and lean formulas in A8-lean-bread-formulas.
• Sourdough / Real Bread positioning → live starter, long ferment, no additives. Command a premium and label it honestly. See fc-sourdough-real-bread.

The catalogue "shopping list" for all three routes is shown in img-b7cw-08 and tabulated in data.json → cmp-catalogue: strong Bread Flour Type 750, Puratos S500 improver, BeneoPro VWG 75 vital wheat gluten, Cardowan high-ratio shortening, Lesaffre Benevia fresh yeast and EDME diastatic malt flour — each backed by a first-party spec sheet.

Allergen and food-safety note (flagged for human review)

• Gluten is everywhere in this dossier. Wheat flour, vital wheat gluten (wheat), diastatic malt flour (barley) and the improver's flour carrier all declare cereal gluten. None of these products is suitable for coeliacs; the S500 improver spec explicitly states "not suitable for coeliacs" and flags egg, soya and milk as possible cross-contamination.
• The Cardowan shortening is declared free of all 14 legal allergens; Benevia yeast carries no declared allergen. Its spec states that the sulphites belong to the production molasses rather than the finished yeast — a first-party position that is not independently verified, so do not make a "sulphite-free" claim without confirming it with the supplier and against the current spec sheet.
• Fortificants and any declarable processing aids (e.g. ascorbic acid carried in some flour batches) must be handled per UK food-information law (retained Regulation (EU) 1169/2011). The folic-acid mandate and the fortification minima are legal requirements, not options — confirm current wording with your miller and the FSA before finalising labels.
• All numeric, dosage, regulatory and allergen claims here are cross-cited in sources.json and should receive a final human review before publication or customer use.

Related reading

Pillar A (the craft science): A5-dough-mixing-methods · A5-bulk-fermentation · A5-sourdough-technology · A5-scaling-artisan-to-industrial · A5-bread-improvers-enzymes · A5-shelf-life-and-staling · A3-what-is-a-bread-improver · A3-ascorbic-acid-oxidants-reductants · A3-emulsifiers-in-bread · A3-enzymes-in-bread · A3-vital-wheat-gluten · A3-clean-label-improvers · A3-malt-and-malt-extracts · A3-improver-selection-guide · A1-protein-gluten-and-strength · A1-key-quality-parameters · A1-wheat-flour-types-by-application · A1-wholemeal-and-high-extraction · A2-yeast-types-comparison · A2-preferments-poolish-biga-sponge · A2-sourdough-cultures-science · A4-fat-types-and-selection · A8-lean-bread-formulas.

British siblings (Pillar B7): B7-flour-landscape · B7-sourdough-real-bread · B7-malted-grain-baking.