Ingredients
Flour protein content for bread: what the number means and what to buy
Bread flour runs 11.5 to 13.5 percent protein; under 11 is pastry, over 14 suits enriched doughs and long fermentations. Protein quality matters as much as the number.
The protein figure on a bag of flour is the most quoted number in a bakery and the least understood. It is a proxy. What a baker actually wants to know is how much gluten the flour will form and how that gluten behaves: how strong, how extensible, how long it holds up. Protein content predicts that reasonably well within one wheat variety and one mill, and badly across different ones.
What the percentage measures
Wheat protein is mostly two families, glutenins and gliadins. When hydrated and worked they form gluten, the network that traps the gas of fermentation. Glutenins give strength and elasticity; gliadins give extensibility. The label reports total protein, so two flours at 12.5 percent can behave differently if their glutenin-to-gliadin balance differs, which it does between varieties, growing seasons and mills.
Protein is measured by nitrogen content, and the figure depends on the moisture basis used. A flour listed at 12 percent on a 14 percent moisture basis reads about 14 percent on a dry basis, because the same protein is divided by less mass. Bags rarely say which. Compare within one supplier’s range, not across catalogues.
The ranges bakers use
| Protein (14 % mb) | Typical name | Suits |
|---|---|---|
| 8 to 10 % | Cake, pastry, “00” for pasta | Short doughs, laminated pastry, fresh pasta |
| 10 to 11.5 % | Plain, all-purpose, T55 | Baguette, ciabatta, quick breads, short fermentation |
| 11.5 to 13 % | Bread flour, strong flour | Sourdough, hearth loaves, pizza with 24 to 48 hour fermentation |
| 13 to 14.5 % | Very strong, high-gluten, Manitoba | Tin loaves, bagels, panettone, heavily seeded doughs |
| above 14.5 % | Vital wheat gluten blends, reinforcing flour | Blending into weak flours |
Whole wheat flours carry higher protein numbers, often 13 to 15 percent, but bran and germ cut through gluten strands, so the effective strength is lower than the figure implies. Treat a 14 percent whole wheat like a 12 percent white in the dough.
Heirloom and ancient wheats break the rule altogether. Einkorn, emmer, spelt and many old landrace varieties can show 13 to 15 percent protein on the bag and still behave like a weak flour: their gluten is soft and extensible, with little of the elasticity that holds gas through a long proof. A dough made from them wants less water, a shorter and gentler mix, less handling and a shorter fermentation, and it will spread if treated like a strong bread flour. With these flours the protein figure is close to useless; a test bake, or the mill’s own advice, tells you more.
Strength measured directly
Mills in Italy, France and Spain report W rather than protein. W comes from the alveograph and measures the work needed to blow a bubble of dough until it bursts. A second figure, P/L, gives the balance between tenacity (P) and extensibility (L).
- W below 180: weak; biscuits, cakes, some flatbreads.
- W 180 to 260: medium; daily bread, pizza with same-day or overnight fermentation, short-fermented loaves.
- W 280 to 350: strong; 24 to 72 hour fermentations, most sourdough, doughs with a lot of preferment.
- W above 350: very strong; panettone and other rich doughs, or blending into weaker lots.
P/L, the balance between tenacity and extensibility, sits around 0.5 to 0.7 for bread flours; higher means a tight dough that resists stretching.
German and Central European mills use ash-based type numbers (550, 1050) that say nothing about strength; ask for the protein or a farinograph figure separately.
Matching flour to process
Long fermentation eats strength. Acids and enzymes weaken gluten over time, so a dough that ferments 36 hours needs a flour that starts stronger than a dough baked in six. The same is true for anything that cuts gluten: seeds, bran, rye, and fat in quantity. Conversely, a strong flour in a short process produces a chewy, tight loaf with muted flavour.
A rough rule: choose the weakest flour that still holds its shape through your fermentation. It will give a more open crumb, a more tender bite and more flavour than a stronger one.
Blending, and why bakeries do it
A bakery with two flours can cover most of the table above by blending. A 13.5 percent strong white and a 10.5 percent plain flour mixed half and half behave close to a 12 percent bread flour. Blending also smooths out crop-year variation: when a new harvest arrives weaker than the last, adding ten percent of the strong flour brings the dough back without changing the recipe.
Water absorption follows protein
Stronger flours absorb more water; a common rule of thumb is about 1.5 percent more water for each additional percent of protein, though the mill’s farinograph figure is the reliable number. A recipe developed at 75 percent hydration on a 12.5 percent flour will feel loose on an 11 percent flour and stiff on a 14 percent one. When a supplier changes the lot, expect the first mix to tell you.
Keeping the number where you can see it
The protein or W of every flour you buy belongs in the ingredient record next to the price and the supplier, because it is what explains a dough that suddenly behaves differently. It also drives ordering: a bakery that uses two flours in fixed proportions can forecast both from the production plan, and the stronger flour is usually the one that runs out first because it gets added to fix the weaker.
Questions bakers ask
What protein content is best for bread?
For lean hearth loaves and sourdough, 11.5 to 13 percent. For tin bread, bagels and doughs carrying a lot of seeds or fat, 13 to 14. Below 11 percent the dough struggles to hold gas through a long fermentation.
Does higher protein mean better bread?
No. It means a stronger, more elastic dough that tolerates mixing and long proofs. Too strong and the crumb turns tight and chewy and the flavour flat. Match the strength to the process, not to the largest number on the bag.
What is W in flour strength?
W is the Chopin alveograph measure used across Southern Europe: the energy needed to inflate a dough bubble until it bursts. W 180 to 260 suits daily bread and short fermentation, W 280 to 350 suits long fermentation and rich doughs, above 350 is reinforcing flour.
Know the day you run out
Type your main ingredients into the free flour forecast and get the run-out date and the order-by date. bakeryOS runs the same maths from your production plan.
Open the flour forecastSources: Suas, Advanced Bread and Pastry; Hamelman, Bread, 3rd ed.; Cereals & Grains Association (formerly AACC International), Approved Methods: alveograph 54-30 and farinograph 54-21. Updated 2026-09-09.