All-purpose flour is a blend of hard and soft wheat; it may be bleached or unbleached. Flour that is bleached naturally as it ages is labeled unbleached, while chemically treated flour is labeled bleached. Bleached flour has less protein than unbleached. Bleached is best for pie crusts, cookies, quick breads, pancakes and waffles. Use unbleached flour for yeast breads, Danish pastry, puff pastry, strudel, Yorkshire pudding, eclairs, cream puffs and popovers.

Bread flour is white flour made from hard, high-protein wheat. It has more gluten strength and protein content than all-purpose flour. It is unbleached and sometimes conditioned with ascorbic acid, which increases volume and creates better texture. This is the best choice for yeast products.

Whole-wheat flour is made from the whole kernel of wheat and is higher in dietary fiber and overall nutrient content than white flours. It does not have as high a gluten level, so often it's mixed with all-purpose or bread flour when making yeast breads.

Instant flour (Wondra from Gold Medal) is granular and formulated to dissolve quickly in hot or cold liquids. It will not work as a substitute for all-purpose flour, although there are recipes on the container for popovers and other baked goods. It is used primarily in sauces and gravies.

Cake flour is a fine-textured, soft-wheat flour with a high starch content. It has the lowest protein content of any wheat flour. It is chlorinated (a bleaching process), which leaves the flour slightly acidic, sets a cake faster and distributes fat more evenly through the batter to improve texture. When you're making baked goods with a high ratio of sugar to flour, this flour will be better able to hold its rise and will be less liable to collapse. This flour is excellent for baking fine-textured cakes with greater volume and is used in some quick breads, muffins and cookies.

Pastry flour also is made with soft wheat and falls somewhere between all-purpose and cake flour in terms of protein content and baking properties. Use it for making biscuits, pie crusts, brownies, cookies and quick breads. Pastry flour makes a tender but crumbly pastry. Do not use it for yeast breads. Pastry flour (both whole-wheat and regular) is not readily available at supermarkets, but you can find it at specialty stores and online.

Self-rising flour, sometimes referred to as phosphated flour, is a low-protein flour with salt and leavening already added. It's most often recommended for biscuits and some quick breads, but never for yeast breads.

Semolina flour is used in making pasta and Italian puddings. It is made from durum wheat, the hardest type of wheat grown. The flour is highest in gluten.

Durum flour is grown almost exclusively in North Dakota.

Organic flour is used in the same way as regular flour. It must follow U.S. Department of Agriculture regulations to be labeled organic. Using this flour is a matter of personal preference.