Wheat Classes: What Is Actually in the Bag
An American flour bag names a use — bread, cake, all-purpose — and sometimes a protein figure. Behind the name is a choice of wheat class, and the classes are fixed in federal grain law. Knowing which wheat makes which flour explains most of the differences between the bags.
The eight legal classes
US grain standards (7 CFR 810.2202) set “eight classes for wheat”: Durum, Hard Red Spring, Hard Red Winter, Soft Red Winter, Hard White, Soft White, Unclassed, and Mixed. The last two are catch-alls: unclassed for a variety that fits nowhere else, mixed for a lot with less than 90 per cent of any one class. Spelt, einkorn, emmer and khorasan are not named in the US grading definition of wheat at all.
The six working classes, with U.S. Wheat Associates’ typical protein ranges (12 per cent moisture basis):
| Class | Where it grows | Typical protein | What it becomes |
|---|---|---|---|
| Hard Red Winter | Great Plains, Pacific Northwest, California — the most widely grown class | 10.0–13.0% | Pan breads, hard rolls, croissants, flatbreads, Asian noodles, general-purpose flour |
| Hard Red Spring | North Central states | 12.0–15.0% | Bagels, hearth and artisan breads, pizza crust; blended in to strengthen weaker flours |
| Soft Red Winter | The eastern third of the country | 8.5–10.5% | Cakes, cookies, crackers, confectionery |
| Soft White | Mainly the Pacific Northwest, about 80% exported | 8.5–10.5% | Sponge cakes, pastries, Asian noodles |
| Hard White | Central Plains, Montana, Idaho, California — the newest and smallest class | 10.0–14.0% | Asian noodles, whole-wheat and high-extraction flours, pan and flatbreads |
| Durum | North Dakota, Montana; “Desert Durum” under contract in Arizona and California | 12.0–15.0% | Pasta, couscous, some Mediterranean breads |
These are typical ranges. FGIS’s own sampling shows much wider tails — hard red winter samples from under 8 to over 18 per cent protein — which is why a mill blends lots to hit a specification.
The 2025 crop (NASS, September 2025) was 1.98 billion bushels: hard red winter 804 million, hard red spring 458 million, soft red winter 353 million, soft white about 259 million, durum 86 million, hard white about 24 million.
”Red” and “white” are the bran, not the flour
The colour class names the bran. Red wheats carry a reddish-brown pigment in the seed coat, along with the tannins that give red whole-wheat its slightly bitter edge. Hard white wheat has a pale bran and lower polyphenol oxidase, so its whole-grain flour is lighter in colour and milder in taste. That is what “white whole wheat” flour is: whole-wheat flour milled from white wheat. There is no separate legal category for it. King Arthur’s “Golden Wheat,” used in the 100% Whole Wheat Sandwich Bread, is a white whole wheat.
White flour made from red wheat is still white, because the bran is gone.
Bread, cake and all-purpose are not legal grades
The US standards of identity for wheat flour (Milling) have no standard for bread flour, cake flour, pastry flour, all-purpose flour or high-gluten flour. Those names are trade terms, defined by each mill. In practice they map onto wheat class and protein:
- Bread and high-gluten flour — hard spring or hard winter wheat, high protein.
- All-purpose — a blend, often of hard and soft wheat, or a moderate hard winter wheat.
- Pastry and cake flour — soft wheat, low protein; cake flour usually chlorinated (The Science).
- Southern all-purpose (the White Lily style) — soft wheat throughout, which is why biscuits made with it are so tender. White Lily describes its flour as made from “100% soft red winter wheat once grown primarily in the South”; the brand does not publish a protein figure, and the “8 per cent” seen on retailer pages is not the brand’s own number.
What the brands themselves publish
Only a few mills print a protein figure, and they do not all mean the same basis. These are the published numbers, and only those:
| Flour | Protein, as published | Wheat, as published |
|---|---|---|
| King Arthur All-Purpose | 11.7% | — |
| King Arthur Bread | 12.7% | — |
| King Arthur Whole Wheat | 13.2% | — |
| King Arthur High-Gluten | 14.2% | — |
| King Arthur Cake | 10% | — |
| King Arthur Pastry | 8% | — |
| Bob’s Red Mill Unbleached All-Purpose | 10–12% | hard red wheat |
| Bob’s Red Mill Artisan Bread | 12.5–13.5% | hard red wheat |
| Bob’s Red Mill Whole Wheat | 13–15% | hard red wheat |
| Bob’s Red Mill Ivory Wheat | 11–13% | hard white wheat |
| Bob’s Red Mill Fine Pastry | 8–9% | soft white wheat |
| Bob’s Red Mill Super Fine Cake | 7–8% | soft white wheat |
| Gold Medal Medallion Bakers All-Purpose (foodservice) | 11.25% | “a selected blend of hard and soft wheat” |
| Pillsbury BEST Bakers Patent (foodservice) | 12.9% | “a spring wheat flour” |
| Caputo Pizzeria (Tipo 00) | 12.5% | — |
| Caputo Pasticceria (Tipo 00) | 11% | — |
Several gaps are worth noting:
- Retail Gold Medal and Pillsbury bags publish no protein percentage on the brands’ own pages. Their nutrition panels give grams per quarter-cup, which cannot be read as a specification.
- Gold Medal’s foodservice page gives 11.25 per cent protein while its own panel lists 10.5 g per 100 g. The two figures are on different moisture bases, and the page does not say which.
- Store-brand (private-label) flours publish no protein figures at any retailer checked.
King Arthur states that the protein printed on its bags “will always match the flour inside of it.”
What this means in a kitchen that buys store brands
A store-brand bag of bread flour is almost certainly hard red wheat from the Plains or the Northern states; store-brand all-purpose is a blend chosen to be adequate at everything. The practical consequences follow from the classes:
- For a chewy bread, bagel or pizza, a bread or high-gluten flour from hard wheat.
- For tender biscuits, pie crust and cake, a low-protein soft-wheat flour — pastry flour, a Southern all-purpose, or cake flour.
- For most everything else, all-purpose.
- Where a recipe gives a protein figure and the bag does not, the figures above from the brands that publish are the only honest reference.
In this section: History · The science · Milling · Wheat classes · Reading the label · Heritage wheats · Michigan · Home milling · Rye, barley, oats · Corn, rice, starches · Buckwheat and small grains · Legume, nut, seed · Gluten-free · Safety and storage · Corrections
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