Whole wheat flours. Whole wheat flours use every part of the kernel: the fiber-rich bran
with its B vitamins, the starch- and protein-rich endosperm with its iron and B vitamins,
and the oily germ with its vitamin E.* Because they contain bran, whole-grain flours have
much more fiber than refined white flours. However, some studies suggest that the size of
the fiber particles may have some bearing on their ability to absorb moisture and “bulk up”
stool and that the fiber particles found in fine-ground whole wheat flours may be too small
to have a bulking effect.
Finely ground whole wheat flour is called whole wheat cake flour; coarsely ground whole
wheat flour is called graham flour. Cracked wheat is a whole wheat flour that has been cut
rather than ground; it has all the nutrients of whole wheat flour, but its processing makes it
less likely to yield its starch in cooking. When dried and parboiled, cracked wheat is known
as bulgur, a grain used primarily as a cereal, although it can be mixed with other flours and
baked. Gluten flour is a low-starch, high-protein product made by drying and grinding hard-
wheat flour from which the starch has been removed.
Refined (“white”) flours. Refined flours are paler than whole wheat flours because they do
not contain the brown bran and germ. They have less fiber and fat and smaller amounts of
vitamins and minerals than whole wheat flours, but enriched refined flours are fortified with B
vitamins and iron. Refined flour has no phytic acid.
Some refined flours are bleached with chlorine dioxide to destroy the xanthophylls
(carotenoid pigments) that give white flours a natural cream color. Unlike carotene, the
carotenoid pigment that is converted to vitamin A in the body, xanthophylls have no vita-
min A activity; bleaching does not lower the vitamin A levels in the flour, but it does destroy
vitamin E.
There are several kinds of white flours. All-purpose white flour is a mixture of hard and
soft wheats, high in protein and rich in gluten. Cake flour is a finely milled soft-wheat flour;
it has less protein than all-purpose flour. Self-rising flour is flour to which baking powder has
been added and is very high in sodium. Instant flour is all-purpose flour that has been ground
extra-fine so that it will combine quickly with water. Semolina is a pale high-protein, low-
gluten flour made from durum wheat and used to make pasta.
Rye flours. Rye flour has less gluten than wheat flour and is less elastic, which is why it
makes a denser bread.
Like whole wheat flour, dark rye flour (the flour used for pumpernickel bread) contains
the bran and the germ of the rye grain; light rye flour (the flour used for ordinary rye bread)
- The bran is the kernel’s hard, brown outer cover, an extraordinarily rich source of cellulose and lignin.
The endosperm is the kernel’s pale interior, where the vitamins abound. The germ, a small particle in
the interior, is the part of the kernel that sprouts.
Hard wheat has less starch and more protein than soft wheat. It makes a heavier, denser dough.
Gluten is the sticky substance formed when kneading the dough relaxes the long-chain molecules in
the proteins gliadin and glutenin so that some of their intermolecular bonds (bonds between atoms
in the same molecule) break and new intramolecular bonds (bonds between atoms on different mol-
ecules) are formed.
Flour