½ cup flour

Flour is a fine powder produced by grinding cereal grains, most commonly wheat (Triticum aestivum). The grinding process breaks down the grain kernel into its constituent parts—endosperm, bran, and germ—with varying proportions depending on the milling method and flour type. All-purpose flour, the most ubiquitous variety, typically contains 10-12% protein and consists primarily of the starchy endosperm with some bran and germ reintroduced. Whole wheat flour retains all kernel components, while refined white flour removes the bran and germ, resulting in a lighter color and finer crumb structure. Soft wheat flours (cake, pastry) contain less protein than hard wheat flours (bread), affecting gluten development and final texture.

Different grains yield distinct flours with varying protein profiles and characteristics: rye flour contributes earthiness and density, spelt flour offers a slightly sweet nuttiness, and corn flour provides a distinctly grainy sweetness. The milling process itself—roller milling versus stone grinding—also influences the flour's performance in baking, affecting hydration requirements and fermentation rates.

Flour serves as the foundational thickening and structure-building agent across global cuisines. In baking, it forms the gluten network essential to breads, pastries, and cakes, with protein content dictating the final texture and rise. Beyond sweet applications, flour functions as a binder in sauces (roux), a coating for fried foods, and a thickener for gravies and braises. Different flour types are selected strategically: bread flour for chewy, open crumbs; cake flour for tender, delicate structures; and all-purpose flour for versatile everyday baking. It also appears in dumplings, noodles, and batters across Asian, European, and American traditions. The measure of "½ cup flour" typically represents approximately 60 grams by weight, though precise measurement by weight is preferred for consistent results.