All-purpose flour is a white flour milled from hard wheats or a blend of hard and soft wheats. It gives the best results for many kinds of products, including some yeast breads, quick breads, cakes, cookies, pastries and noodles. All-purpose flour is enriched and may be bleached or unbleached. Bleaching will not affect nutrient value. Unbleached, and in some cases conditioned with ascorbic acid, bread flour is milled primarily for commercial bakers, but is available at most grocery stores.
Cake flour is fine-textured, silky flour milled from soft wheats with a low protein content.
It is used to make cakes, cookies, crackers, quick breads and some types of pastry. Cake flour has a greater percentage of starch and less protein, which keeps cakes and pastries tender and delicate. It is commonly used in biscuits and quick breads, but is not recommended for yeast breads. One cup of self-rising flour contains 1 teaspoons of baking powder and teaspoon of salt. Pastry flour has properties intermediate between those of all-purpose and cake flours.