APF stands for all-purpose flour, the most common type of wheat flour used in home cooking and baking. It typically contains 10 to 12% protein, which places it squarely between delicate cake flour and strong bread flour. That middle-ground protein content is exactly why it works across such a wide range of recipes, from cookies and muffins to pan sauces and fried chicken coatings.
What Makes APF “All-Purpose”
The versatility comes down to protein. When flour meets water, two proteins in wheat (glutenin and gliadin) link together to form gluten, the elastic network that gives baked goods their structure. Cake flour has too little protein to make decent bread, and bread flour has too much to produce tender cookies. APF sits in the sweet spot where it can do both reasonably well, even if it won’t be perfect at either extreme.
Most all-purpose flour is milled from hard wheat varieties. The exact protein percentage varies by brand, and that variation matters more than most home bakers realize. King Arthur all-purpose flour clocks in at 11.7% protein, while White Lily, a Southern staple, runs between 7 and 8.5%. A recipe developed with one brand can behave noticeably differently with another, especially in bread or pastry where gluten development is critical.
Bleached vs. Unbleached APF
You’ll find both bleached and unbleached versions on store shelves. Freshly milled flour has a yellowish tint from natural pigments called carotenoids. Unbleached flour loses that color slowly over time through exposure to air. Bleached flour gets there faster through chemical treatment with agents like benzoyl peroxide or chlorine gas, which destroy the yellow pigments and turn the flour bright white.
The bleaching process does more than change color. It also modifies the flour’s proteins through oxidation, encouraging them to form stronger connections with each other during baking. Bleached flour tends to have a finer grain and softer texture, which makes it slightly better suited to tender baked goods like cakes and quick breads. Unbleached flour has a very slightly off-white appearance and a more neutral flavor that many bakers prefer. Nutritionally, the two are nearly identical: same calories, same protein, same carbs per cup.
Enrichment: What’s Added Back
During milling, the bran and germ are stripped away, and with them go most of the naturally occurring vitamins. U.S. federal regulations require enriched flour to contain specific amounts of added nutrients per pound: 2.9 milligrams of thiamin, 1.8 milligrams of riboflavin, 24 milligrams of niacin, 0.7 milligrams of folic acid, and 20 milligrams of iron. Calcium is optional but permitted up to 960 milligrams per pound. If your bag says “enriched” (and most do), it contains all of these.
How APF Compares to Other Flours
The practical differences show up most clearly in bread. When you use all-purpose flour instead of bread flour, the gluten network is weaker because there’s less protein available. The dough can’t stretch as far to accommodate gas bubbles during rising, so you get smaller bubbles and a tighter, denser crumb. In side-by-side baking tests, focaccia made with bread flour came out taller and airier with much more open bubbles, while baguettes made with bread flour had a springier, chewier texture and better oven spring.
That said, APF still makes great bread. It’s particularly well suited to quick breads like Irish soda bread that are meant to have a denser texture, and it performs nearly identically to bread flour in enriched doughs like milk bread. Many professional bakers use it daily and prefer it for certain loaves.
On the pastry side, APF produces slightly less tender results than cake flour or pastry flour, but the difference is manageable. If a recipe calls for cake flour and you only have APF, you can approximate it: for every cup of cake flour needed, measure one cup of all-purpose flour, remove two tablespoons, and replace them with two tablespoons of cornstarch. This lowers the effective protein content and mimics the finer texture of cake flour.
Common Uses Beyond Baking
APF isn’t just for cakes and bread. It’s the standard thickener for pan gravies and roux-based sauces, where a tablespoon or two cooked in fat creates a smooth base. It coats chicken, fish, and vegetables before frying, giving them a crisp outer layer. It binds meatballs and meatloaf. It thickens stews and soups. When a recipe simply says “flour” without specifying a type, it means all-purpose flour.
Storage and Shelf Life
Stored in its original bag in a cool, dry pantry, all-purpose flour lasts about a year from its packaging date. Transferring it to an airtight container after opening doesn’t extend that timeline much, but it does protect against moisture, odors, and pantry insects. If you bake frequently and use flour within a few months, a pantry container is fine. If you only pull it out occasionally, store it in the freezer, where it keeps indefinitely. Let it come to room temperature before using it in baking, since cold flour can throw off dough temperatures.
Because all-purpose flour is refined (no bran or germ), it contains very little fat and stays fresh much longer than whole wheat flour, which can go rancid in a matter of months at room temperature.