All About Flour

There are two types of wheat: hard and soft. The key difference between them is protein content. Hard wheat is higher in protein than soft wheat--and it is the protein that contains the gluten that allows breads and other baked goods to rise.

Where wheat is grown can determine protein content: Northwestern U.S. and western Canada produce hard wheat that's very high in protein, while the southern U.S. states grow a softer wheat with less protein.

All-purpose flour includes a happy balance of hard and soft flours. And as the name suggests, it is a type of flour that lets you make a wide variety of baked goods--cookies, cakes, muffins, quick breads, biscuits, and pie crusts--without having to stock up on multiple types of flour.

One cup of AP flour = 4.5 oz (128 g)

But with flour, one size doesn't always fit all. One type of flour is best for baking bread, another type for pastries. Bread, for example, benefits from a high-protein flour.

When combined with water and developed by mixing and kneading, the gluten becomes elastic and stretches around gas bubbles produced by the yeast. When gas bubbles expand in the oven, the gluten goes along for the ride. The result is a nice fat loaf of bread.

Interestingly, of all the grains, wheat is the only one that packs gluten-producing proteins. To rise properly, breads made with other grains (like rye, corn, or oats) must be fortified with wheat flour or gluten.

Note: As a home baker, you can ignore language on bread flour labels saying "first clear flour," "patent flour," and "high gluten flour." You'll be fine with the blend of bread flour in any national brand.

One cup of bread flour = 4.8 oz (136 g)

Pastry flour is a medium-protein flour that produces tender pie crusts. If you use a flour with too much protein, your pastry can become tough; too little, and the pastry can be brittle and hard to work with. Medium is just right.

In a pinch, you can make your own version of pastry flour by combining one part cornstarch to two parts all-purpose flour.

One cup of pastry flour = 4.25 oz (120 g)

Cake flour is a lower-protein flour that's also bleached with chorine, which alters the structure of the starches and fats and makes the flour slightly acidic. Unfortunately, substituting all-purpose flour in recipes that have been specifically formulated for cake flour will not produce happy results. Always sift cake flour before using it in a recipe.

One cup of cake flour = 3.9 oz (111 g)

Whole wheat flour contains all of the nutrients found in the wheat kernel and results in dense, hearty baked goods. If 100% whole wheat bread tastes a little bit too healthy for you, try a ratio of half whole wheat, half bread flour.

Note: You might need to adjust your liquids to hydrate the flour fully (use more water if you're adding whole wheat flour to a recipe, less if you're substituting bread flour for whole wheat).

One cup of whole wheat flour = 4.25 oz (120 g)

Self-rising flour is used for quick breads, biscuits, muffins, and pancakes. It already contains baking powder, so don't need to add any leavening agents.

To make your own self-rising flour, add 1½ tsp baking powder per cup of flour (or 5-7 g of baking powder per 100 g of flour).

Special bread machine flours are generally just high-protein flours, although some brands might contain dough conditioners like malted barley flour (diastatic malt powder), ascorbic acid, or lecithin.

Freshly ground wheat might smell great, but it doesn't make an optimum loaf: as flour ages, it creates stronger gluten, resulting in a more elastic dough and a lighter loaf. Aging also changes the color of flour from pale yellow to white. Millers have sped up this aging process with chlorine and ascorbic acid (vitamin C) , which also helps the flour look whiter.

The wheat berry is made up of bran, germ, and endosperm:

• The bran is the hard outer shell that covers the wheat berry. An excellent source of fiber, the bran also contains most of the minerals. Because the bran has sharp edges, which interfere with gluten development, it is removed during milling--and then often added back in later.
• The germ is the part of the grain that would become the plant. Wheat germ is very high in protein and B vitamins. It is removed in the milling process because its high fat content causes the flour to become rancid more quickly. Wheat germ should be stored in the refrigerator.
• The endosperm is the food that the seed would consume on its way to becoming a plant. The flour that we use for baking, unless it is whole wheat, has had the germ and the bran removed. The remaining endosperm is composed mostly of starch and protein.