What Is It?
White bread flour is milled from hard red or hard white wheat, with most of the bran and germ removed, leaving you with predominantly endosperm. That endosperm is rich in two proteins — glutenin and gliadin — which combine with water to form gluten. More protein means more gluten. More gluten means structure. Structure means your loaf doesn't pancake out across the Dutch oven like it's trying to escape.
The "bread" distinction matters. All-purpose flour runs 10–12% protein; bread flour typically lands between 12–14%. That extra percentage or two might not sound like much, but in a high-hydration sourdough where you're asking the dough to hold together for 12+ hours of fermentation, it's the difference between a bold ear and a flat disappointment.
Protein & Why It Matters
Every flour's behavior in sourdough is downstream of one number: protein content. Here's how white bread flour stacks up against the others.
*Rye and einkorn both have plenty of protein — but it forms weak, fragile gluten, the opposite of what the number suggests. The number isn't everything; see those pages for the full picture.
How It Handles
White bread flour is forgiving in ways that make it the best teaching flour there is. It builds strong, elastic gluten that tolerates rough treatment, holds its shape during proofing, and gives you a meaningful ear under decent scoring. It can handle hydration from a sensible 72% all the way up to 82–85% in the hands of someone who knows what they're doing.
Steady and readable. Bulk ferment typically runs 4–6 hours at 76°F with a healthy starter. It won't surprise you.
Start at 72–75% if you're new. Once your shaping is tight, push toward 78–80% for a more open crumb.
Excellent. Strong gluten holds all that fermentation gas until the crust sets. This is what gives you height.
Clean and mild. The sourdough tang comes through clearly — no competition from the grain itself.
The Brands Worth Knowing
In the US, the conversation usually starts and ends with King Arthur — and for good reason. Their bread flour runs a consistent 12.7% protein, it's unbleached, unbromated, and non-GMO, and you can find it at almost any grocery store in the country. It's what Oso gets fed most days.
United States
| Brand | Protein | Notes | Find It |
|---|---|---|---|
| King Arthur Bread Flour | 12.7% | The benchmark. Unbleached, non-GMO, consistent. Organic version available. | Nationwide |
| Central Milling Organic Bread Flour | 12.5% | Tartine's flour of choice. Harder to find in stores; order direct or online. | Online / Specialty |
| Bob's Red Mill Artisan Bread Flour | ~12.5% | Solid, accessible, widely stocked. Good everyday option. | Nationwide |
| Cairnspring Expanse Bread Flour | 12–13% | Pacific Northwest heritage wheat. Exceptional flavor. Small-batch mill. | West Coast / Online |
| King Arthur Sir Lancelot | 14.2% | High-gluten for ultra-high hydration bakes (85%+). Professional use. | Online / Specialty |
Europe & International
| Country / Type | Common Name | Approx. Protein | Notes |
|---|---|---|---|
| France | Farine T65 | 11–12% | The standard for French country bread. Slightly more mineral flavor than US bread flour. |
| Italy | Tipo 0 / Manitoba | 11–14% | Manitoba Oro Tipo 00 at 13% is a cult favorite for high-hydration sourdough. |
| UK | Strong White Bread Flour | 12–13% | Shipton Mill, Marriages, and Doves Farm are the go-to brands. |
| Germany | Type 550 | ~11% | The German equivalent of French T65. Common in rye-wheat blends. |
| Australia | Baker's Flour | 12–13% | Laucke and Allied Mills are the standard. Equivalent to US bread flour. |
The Organic Question
Organic bread flour does perform slightly differently — not dramatically, but noticeably. Because organic wheat isn't treated with certain pesticides and chemicals, the bran retains more wild yeast and bacteria even after milling. Your starter tends to be more active, and the fermentation smells rounder and more complex.
If your budget has limits (whose doesn't), an easy middle ground: use organic flour for your starter feedings, and conventional for the bulk of your bake. You get the flavor benefits where they matter most without tripling your flour costs.
Storage
Bread flour is a kitchen staple, not a pantry artifact. Store it in a cool, dry place in a sealed container — a lidded bin beats the original paper bag. Protein content and enzyme activity both degrade over time, so flour older than six months can give you a sluggish starter and weaker gluten development. Buy smaller quantities more often if you're baking less than once a week.
In summer, if your kitchen runs hot, consider keeping a portion in the fridge. Bring it to room temperature before mixing — cold flour will throw off your bulk ferment timing.