The British Real Bread and sourdough revival: the UK Sourdough Code of Practice, long-ferment technique and artisan positioning

Two Britains of bread, and where sourdough sits

Walk into any British supermarket and you are looking at two completely different traditions on the same shelves. Most of it - roughly eight in ten UK loaves - is made by the Chorleywood Bread Process (CBP): a fast, additive-assisted, high-energy method that turns flour into sliced, wrapped bread in under four hours. The other tradition is craft bulk-fermentation - time, not machinery, builds the loaf - and it accounts for only around 3% of the market, but it is growing, and it trades under a banner: Real Bread. (The CBP vs craft divergence is the subject of its sibling dossier B7-chorleywood-vs-craft; this one is about the craft end, and its flagship product: sourdough.)

Sourdough is where craft baking meets a premium price and a strong story. It is also where British labelling is at its messiest, because - and this is the single most important fact for a UK baker to internalise - there is no legal definition of "bread", "sourdough" or "artisan" in UK law. A plant loaf leavened with baker's yeast and a fistful of additives can legally wear the word "sourdough" on its bag. That vacuum is what this dossier is really about: how to make genuine sourdough, how to buy for it, and how to label it honestly in a market where the word alone guarantees nothing.

For the science of why sourdough works - the wild yeast and lactic acid bacteria (LAB) balance, the acidification curve, the flavour chemistry - read the Pillar A articles A2-sourdough-cultures-science and A5-sourdough-technology. This article assumes that grounding and concentrates on the British picture: regulation, technique, flour and catalogue.

The labelling battleground: the UK Sourdough Code of Practice vs "Real Bread"

The Real Bread Campaign and "sourfaux"

The Real Bread Campaign was launched on 26 November 2008 by the charity Sustain with baker and author Andrew Whitley (Bread Matters). Its definition of Real Bread is deliberately blunt: bread made without chemical raising agents, so-called processing aids or any other additives. The only thing it permits is fortificants that must be added to flour by law (so white and brown Real Bread are possible, not just wholemeal). Real Bread, it points out, can be made from as little as flour, water and salt - and it estimates that around 95% or more of what is sold as "bread" in the UK falls short of even that low bar.

On top of that sits the Campaign's genuine-sourdough definition, which is stricter still. To be genuine sourdough, bread must be:

1. leavened only using a live sourdough culture - no added commercial (baker's) yeast, no baking powder or any other raising agent;
2. made without additives; and
3. made without other souring or flavouring agents - no vinegar, no yoghurt, no dried sourdough powder to fake the tang.

In 2015, Campaign co-ordinator Chris Young coined the word "sourfaux" for any product marketed as sourdough but made with additives and/or an alternative raising agent instead of (or as well as) a live culture. In a 2019 investigation the Campaign named four of Britain's largest industrial bread makers - Warburtons, Hovis, Allinson's and Roberts - selling products that used "sourdough" wording but were made with baker's yeast and/or additives, with ingredient lists that included vinegar, ascorbic acid, soya flour, fermented wheat flour, the emulsifier E472e and the preservative E282 (calcium propionate). None of these, in the Campaign's view, is sourdough.

The ABIM Code of Practice (January 2023): three tiers

In response to exactly this confusion, the Association of Bakery Ingredient Manufacturers (ABIM) published the UK Baking Industry Code of Practice for the Labelling of Sourdough Bread and Rolls on 31 January 2023. It is voluntary and self-regulatory, and it was supported by a wide slice of the industry: the Federation of Bakers, the Craft Bakers Association, Scottish Bakers, the Pizza, Pasta & Italian Food Association and the UK Association of Producers of Yeast among others. It creates three labelling tiers (see the figure below):

• "Sourdough" - the product uses live/active sourdough as the principal leavening agent and may contain a maximum of 0.2% compressed baker's yeast (or the equivalent in cream, liquid, dried or frozen yeast) calculated on the total flour weight, added in the final dough. It must not contain inactive/deactivated/devitalised sourdough, nor additives or flavourings in the final dough beyond mandatory flour fortificants.
• "(product) with sourdough" - commercial baker's yeast is the principal leaven; permitted additives are allowed, and devitalised sourdough may be used.
• "sourdough flavour (product)" - may contain added yeast, additives and raw materials added specifically to increase shelf life or to impart sourdough-type acidity, flavour or aroma.

The Code is a genuine step forward for consumer clarity, and the "with sourdough" / "sourdough flavour" tiers are honest ways to describe a schedule-friendly hybrid or a flavoured loaf. But the Real Bread Campaign rejected it as a "sourfaux code" and a "cheats' charter", precisely because even the top "Sourdough" tier permits 0.2% added yeast - which, for the Campaign, disqualifies a loaf from being genuine sourdough. More than 1,000 sourdough bakers and buyers signed a letter urging the code be withdrawn. The Campaign continues to push for an "Honest Crust Act" that would give legal definitions to marketing terms including sourdough, wholegrain, fresh/freshly-baked, artisan, craft and heritage.

What this means for you. Until the law changes, labelling is a commercial and ethical choice, not a legal one. The practical, defensible line for a UK craft bakery:

• If you leaven only with your own live levain and add nothing else, you can call it sourdough and stand behind it against anyone's definition, including the Campaign's.
• If you add any baker's yeast, or use a dried/liquid preparation that itself contains yeast, be honest: it is a loaf "made with sourdough", not "sourdough". (Our faster hybrid formula below sits here on purpose.)
• If your "sour" comes from an acidulant powder rather than fermentation, the most you can honestly claim is "sourdough flavour" - and many customers who understand the difference will not thank you for it.

The UK rulebook: the Bread and Flour Regulations 1998 (and the 2024 amendment)

Here is the nuance that trips up bakers who think "Real Bread = zero additives, full stop." Under the Bread and Flour Regulations 1998, all non-wholemeal wheat flour milled in the UK must be fortified. So a "flour, water, salt" loaf made with ordinary strong white flour still contains statutory fortificants that were added at the mill - by law, before you ever open the sack. The current minima, per 100 g of flour, are:

• iron ≥ 1.65 mg
• thiamin (B1) ≥ 0.24 mg
• niacin (nicotinic acid) ≥ 1.60 mg
• calcium carbonate (chalk) between 235 and 390 mg

These figures show up verbatim on real datasheets: the first-party Domson White Strong Flour (ADM 4380) sheet declares its ingredient list as Wheat Flour (Wheat Flour, Calcium Carbonate, Niacin, Iron, Thiamin) and quotes typical values of calcium 180 mg, iron 2.5 mg, niacin 2.45 mg and thiamin 0.26 mg per 100 g. (See the figure below for the full table.)

The 2024 amendment. The Bread and Flour (Amendment) (England) Regulations 2024 (SI 2024/1162) add folic acid at 250 micrograms (0.25 mg) per 100 g to non-wholemeal wheat flour, to cut neural-tube defects in early pregnancy. There is a 24-month transition: compliance is required by 13 December 2026. From that date the other minima also rise - iron to ≥ 2.10 mg, niacin to ≥ 2.40 mg, calcium carbonate to 300-455 mg (thiamin unchanged). If you buy white or brown flour, your fortification will change under you in December 2026; the folic acid, iron and niacin figures on your spec sheets will move.

The exemptions matter to sourdough bakers. Fortification does not apply to:

• wholemeal flour (it naturally retains the nutrients), and
• flour from small mills - a mill with a maximum annual production capacity of 500 tonnes - and
• non-wheat flours: spelt, rye, durum and the rest.

This is why so many artisan sourdough bakers gravitate to stoneground, organic and small-mill flours: not only for flavour and provenance, but because those flours can legitimately reach you without added fortificants or a flour-treatment agent. Our first-party Matthews Stoneground Dark Rye datasheet says it plainly in its Additives line - "Statutory flour additives as specified in the Bread and Flour Regulations 1998 and amendments - No Additives needed." That single line is the wholemeal exemption in action.

Ascorbic acid is the catch. The Real Bread Campaign classes ascorbic acid (E300), added enzymes (e.g. alpha-amylase), xanthan gum, fast-acting yeast and preservatives such as propionic acid (E280/E282) as additives/processing aids that Real Bread must not contain (see A3-preservatives-shelf-life and A3-what-is-a-bread-improver for what these do). The trap: many commercial UK bread flours carry ascorbic acid E300 and an enzyme by default - the Domson Strong White sheet lists both a flour-treatment agent (E300) and a carbohydrase enzyme processing aid. Even the Doves Farm Organic Strong White Bread Flour ("BioBake") sheet - organic, Soil Association certified - lists organic wheat flour, ascorbic acid and the statutory nutrients. So if you are marketing a genuinely additive-free Real Bread, you cannot just assume your flour qualifies because it is "strong" or even "organic": read the ingredient line and, if you need E300- and enzyme-free flour, specify a stoneground or small-mill flour that omits them. This is the level of scrutiny the home market rewards.

Building and keeping a starter

Genuine sourdough begins and ends with a living culture (see the figure below). The microbiology - a roughly 1:100 balance of wild yeast to lactic acid bacteria, and how temperature, hydration and feed ratio steer sourness and rise - is covered in depth in A2-sourdough-cultures-science. British bakers do not do anything mystically different here; what matters in practice is:

• A wheat levain built on strong white flour with a little wholemeal or rye for activity, refreshed to peak before use (see the wheat levain build card below). Use it at peak for a rounded, mildly tangy loaf; use it past peak, or run it cool, for a more acetic, sharper crumb.
• A rye starter (rye sour) is more acid-tolerant and is the engine of every good rye loaf. Rye's near absence of functional gluten and its high enzyme and pentosan activity mean acidification does the structural work - which is why rye is traditionally always sourdough-leavened, never simply yeast-raised (A2-rye-sourdough-multi-stage, A5-sourdough-technology). This is common ground across Europe: the Polish zakwas (B1-zakwas-sourdough), the Romanian maia (B4-maia-and-sourdough-tradition) and the Lithuanian raugas (B5-raugas-sourdough-starter) are the same idea in different kitchens.

If you would rather not maintain a mother culture, or you need day-to-day consistency at volume, you can buy in - which brings us to the ingredient shelf and a second sourfaux trap.

Buying sourdough in a tub: genuine culture vs acidulant flavouring

Domson stocks a whole shelf of "sourdough" products, and they are not the same thing (see the figure below and the ready-to-use sourdough comparison table below). Cross-reference A2-ready-use-sourdough-industrial for the full industrial picture; the British buying decision comes down to four formats:

1. Live pure starter cultures - a defined culture you use to build your own levain: Bocker Reinzucht-Sauerteig, Lesaffre Saf-Levain LV1 and Livendo LV-2. Build a clean levain from these and you can bake genuine "Sourdough".
2. Genuine liquid fermented concentrates - actually fermented, ready to dose. The first-party IREKS Natural Liquid Rye Sour sheet is a model of honesty: its ingredients are just rye flour, water and starter culture, it runs at pH 2.8-3.4 with a degree of acidity of 190-210, and you dose it at 1-7% on flour. Zeelandia Bioferm Dark Liquid Sourdough and Amore Wheat Sourdough are the same category.
3. Dried active sourdough - genuine fermented sourdough dried for shelf life, often blended with yeast and enzymes for a consistent result. Puratos O-tentic Durum is a good example: its datasheet lists dried durum wheat sourdough, yeast, ascorbic acid (E300) and enzymes, used at 4% on flour with added water and salt. It is real sourdough - but because it contains added yeast and E300, a loaf made with it belongs in the "with sourdough" tier, not "Sourdough".
4. Acidulant "sourfaux" flavourings - here is the important one to recognise. The product listed in the catalogue as Zeelandia "Sourdough Dry" is, on its own datasheet, a wheat-rye bread improver (article name Superkwas): about 79% rye flour plus about 20% acidity regulators - E330 (citric acid), E270 (lactic acid) and E327 (calcium lactate). It delivers a sour taste by chemical acidification, not fermentation - there is no live culture in it at all. It is a perfectly legitimate ingredient for a fast, tangy loaf, but under the ABIM Code it supports "sourdough flavour" at best, and under the Real Bread definition it is textbook sourfaux.

The lesson for a British buyer: read the ingredient line on the sourdough tub the same way you read the flour sack. "Rye flour, water, starter culture" is fermentation; "acidity regulators E330/E270/E327" is chemistry. Both have their place - just know which you are buying and label the finished loaf honestly.

The craft long-ferment process, step by step

Genuine sourdough is a slow process, and the schedule is the recipe. A typical British craft wheat sourdough runs over roughly 24-36 hours (see the figure below); the numbers below are typical craft starting points, with the underlying science in A5-bulk-fermentation, A5-retarded-cold-fermentation and A5-baking-oven-science.

1. Refresh the levain to peak (4-12 h before mixing).
2. Autolyse - mix flour and most of the water and rest 30 minutes to a few hours. This hydrates the flour and lets enzymes and gentle gluten development get a head start before the salt and levain go in (A5-dough-mixing-methods).
3. Mix in the levain and salt to moderate development - you are not chasing a full mechanical dough as in Chorleywood; time will finish the job.
4. Bulk fermentation - the heart of the loaf. 3-5 hours at around 24-26 C dough temperature, with 3-4 sets of stretch-and-folds in the first couple of hours to build strength without a mixer. This is where flavour, extensibility and the open crumb are made. Judge it by feel and rise, not the clock.
5. Pre-shape, rest, and final shape into a floured banneton, building surface tension.
6. Overnight cold retard - 8-48 hours (commonly 12-18 h) at 4-6 C. Retarding separates production from baking, deepens flavour and gives that blistered crust; it is the single most useful commercial control a small bakery has.
7. Score and bake with steam - a decisive slash at a shallow angle, then 230-250 C with steam (covered pot, or deck with steam injection) so the crust stays supple long enough for maximum oven spring and a raised "ear" before it sets (see the figure below; A5-baking-oven-science). Cool fully before cutting - and for rye, ideally rest a day, or the crumb reads as gummy.

For the formulas in baker's percentage - a British white country loaf, a wholemeal/spelt loaf, a mixed rye, the levain build and a faster "with sourdough" hybrid - see the formula cards below, and A8-bakers-percentage-fundamentals, A8-lean-bread-formulas, A8-preferment-formulas and A8-rye-and-wholegrain-formulas for the maths behind them.

Flour choice for British sourdough

Flour is where the home market gives you real depth of choice (see the figure below; full detail in B7-flour-landscape and A1-protein-gluten-and-strength). The sourdough flour selection table below maps each type to hydration, role and specific Domson products. In brief:

• Strong white bread flour (~12-13% protein) is the backbone of most wheat sourdough: Domson White Strong (protein target 12.0%, water absorption 59.5%), Domson Bread Flour Type 750, Doves Organic Strong White (12.6% protein) and Matthews Windrush Strong White. For very high hydration or wholegrain-heavy loaves, reach for a very strong / Canadian flour such as Centurion Canadian Very Strong, or a T65 for a pain au levain character.
• Wholemeal and high-extraction flours add flavour, fibre and ferment faster, but the bran physically cuts gluten, so you raise hydration and rest the dough longer (A1-wholemeal-and-high-extraction): Doves Organic Strong Wholemeal, Carr's Bakers Wholemeal, Chiltern Wholemeal. If your wholemeal is under-strength, a few percent of vital wheat gluten restores structure (A3-vital-wheat-gluten).
• Rye must be acidified (see above): Doves Organic Wholemeal Rye (a low-protein, high-fibre single-ingredient rye), Matthews Stoneground Rye (Hagberg falling number target ~250) and higher-extraction Wholemeal Rye Type 2000.
• Spelt brings an ancient-grain flavour and an extensible, fast-fermenting dough that over-proofs easily - watch it closely (A1-alternative-grain-flours): Matthews Stoneground White Spelt, Doves White Spelt and Wholemeal Spelt. As a non-wheat flour, spelt is also outside the fortification requirement.
• Diastatic malt flour (a small addition, ~0.2-1% on flour) supplies amylase that both feeds a sluggish culture and builds crust colour - EDME Malt Flour is the catalogue workhorse (A3-malt-and-malt-extracts, B7-malted-grain-baking).

Hydration is the other lever (see the figure below): the same strong white flour gives a tight-ish crumb at ~68%, a classic open crumb at ~75%, and a wildly open but hard-to-handle crumb at ~82%. Push hydration up with flour strength and your own skill, not ahead of them.

Positioning: honesty as the product

Sourdough sits at the premium end of the British bread market for a reason - it takes skill, time and good flour, and customers increasingly know it (see the figures below). In a market with no legal definition, the most valuable thing a craft bakery owns is trust, and the fastest way to lose it is a sourfaux label a knowledgeable customer sees through. The commercially smart position is also the honest one:

• Call genuine, live-only loaves sourdough and be ready to explain why yours is the real thing.
• Sell your faster hybrid proudly as "made with sourdough" - it is a good loaf and an honest claim.
• Reserve acidulant-flavoured products for "sourdough flavour" wording, or use those ingredients where sour is a seasoning rather than the story.

Root your sourdough in the wider British Real Bread repertoire - bloomers, cobs, tin loaves, batch and cottage loaves (B7-regional-breads-map, B7-chorleywood-vs-craft) - and you have a range that tells a single, consistent, defensible story: real ingredients, real time, real bread.

Troubleshooting

The fault table below gives the full diagnostic grid - flat/dense loaves, gummy crumb (the classic rye and under-bake fault), harsh acetic sourness, missing oven spring and ear, slack unworkable dough, pale crust and tunnelling. The recurring British-market fixes: use a levain at peak, keep the dough at 24-26 C, choose a strong enough flour for your hydration, retard to build flavour and control, and steam hard at the start of the bake. Almost every sourdough failure traces back to one of those five.

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Cross-references

• Pillar A science: A2-sourdough-cultures-science, A2-preferments-poolish-biga-sponge, A2-rye-sourdough-multi-stage, A2-ready-use-sourdough-industrial, A2-yeast-types-comparison, A5-sourdough-technology, A5-bulk-fermentation, A5-retarded-cold-fermentation, A5-baking-oven-science, A5-proofing-science, A5-dough-mixing-methods, A1-protein-gluten-and-strength, A1-wholemeal-and-high-extraction, A1-alternative-grain-flours, A3-malt-and-malt-extracts, A3-preservatives-shelf-life, A3-vital-wheat-gluten, A8-bakers-percentage-fundamentals, A8-lean-bread-formulas, A8-rye-and-wholegrain-formulas, A8-preferment-formulas.
• British siblings: B7-flour-landscape, B7-chorleywood-vs-craft, B7-malted-grain-baking, B7-regional-breads-map.
• Shared sourdough heritage: B1-zakwas-sourdough (Polish rye), B4-maia-and-sourdough-tradition (Romanian), B5-raugas-sourdough-starter (Lithuanian).