All-purpose flour is milled from both hard and soft wheat, enough of both to reach a 10 to 12% protein content. The bran (exterior of the wheat kernel) and the germ (inner seed) are removed before milling, leaving the endosperm. Whole-wheat flour is made from everything: the endosperm, bran, and germ. It’s higher in protein (up to 15%) and tends to have more nutrients, fiber, and taste. Both the bran and the germ disrupt gluten formation, so most bakers avoid whole wheat flour because it can make foods dense and even heavy. Baked goods with whole-wheat flour also tend to brown faster.