A grain of wheat is a seed which can grow into a new wheat plant. It is also the part of the wheat plant which is processed into flour. Wheat grains are generally oval shaped, between 5 and 9mm in length and have a crease down one side where they were originally connected to the wheat flower. The wheat grain (or kernel) is divided into several parts, as shown in the diagram.
The outer coating or “shell” of the wheat kernel is made up of several layers. These layers protect the main part of the kernel. Bran is rich in B vitamins and minerals.
This is the main part of the wheat kernel and represents about 80% of the kernel weight. It is from this part that white flour is milled. The endosperm is rich in energy-yielding carbohydrate and important protein.
Germ or Embryo
This part grows into a new plant if sown. The germ lies at one end of the grain and represents only 2% of the kernel. It is a rich source of B vitamins, oil, vitamin E and natural plant fat.
Not all wheats are the same! Wheat varieties are called “clean,” “white,” or “brown” or “hard” if they have high gluten content, and they are called “soft” or “weak” flour if gluten content is low. Hard flour, or bread flour, is high in gluten, with 12% to 14% gluten content, and has elastic toughness that holds its shape well once baked. Soft flour is comparatively low in gluten and so results in a finer or crumbly texture.
There are three general types of flour. White flour is made from the endosperm only. Whole grain or wholemeal flour is made from the entire grain, including bran, endosperm, and germ. A germ flour is made from the endosperm and germ, excluding the bran.
Bread flour or strong flour is always made from hard wheat. It has a very high protein content, between 10% and 13%, making it excellent for yeast bread baking. It can be white or whole wheat or in between. A baker would typically use a white flour with a protein content of 12% and a wholemeal flour with a protein contant of about 13.5% – this higher protein content is necessary to counteract the heaviness of the bran.
All-purpose or plain flour is a blended wheat flour with a protein content lower than bread flour, ranging between 9% and 12%. The higher the protein content the better the flour is for yeast bread baking. Flours sold as all-purpose or plain are also suitable for making flatbreads and soda breads.
Farine fluide is used by French bakers to make baguettes and other specialities. It is a mixture of white bread flour and fine plain flour and is light and free-flowing.
Stoneground wholemeal flour has been ground between two stones. The bran and wheat germ are milled with the rest of the wheat grain. Stoneground flour is considered to have a better flavour but because the oily wheat germ is squashed into the flour it has a higher fat content and may become rancid if stored for too long.
Brown flour contains about 85% of the original grain with some of the bran and wheat germ extracted. It produces a lighter loaf than 100% wholemeal flour.
Granary flour is the name given to a blend of brown and rye flours and malted wheat grain. The malted grain gives the resulting bread a sweet and slightly sticky flavour and texture. Malthouse flour is similar to granary flour.
Wheat germ flour can be brown or white but must contain at least 10% added wheat germ. Bread made with this flour has a pleasant nutty flavour.
Atta flour is a type of flour used in Asia to make chapatis and other flat breads and is made using the endosperm and bran. Most atta is milled from the semi-hard wheat varieties and have a high gluten content. Doughs made out of atta flour are strong and can be rolled out very thin.
Spelt flour is made from a variety of wheat which is no longer widely grown. It makes a rather soft, light loaf with a very good flavour, and it is particularly good for flatbreads because they can become crisp without being hard. It is high in protein but low in gluten making it a possible option to those that are intolerant to other wheat flours.
Semolina is the endosperm before it is fully milled into flour. It can be ground coarsely or finely and is used for certain indian breads such as bhatura.
Cake flour is a finely milled white flour made from soft wheat. It has very low protein content, between 8% and 10%, making it suitable for soft-textured cakes and cookies, but not for bread making.
Graham flour is a special type of whole wheat flour. The endosperm is finely ground, as in white flour, while the bran and germ are coarsely ground. Graham flour is uncommon outside of the USA (but see atta flour, a similar product, below).
Pastry flour or cookie flour or cracker flour has slightly higher protein content than cake flour but lower than all-purpose flour. Its protein content ranges between 9% and 10%. It is available as a white flour, a whole-wheat flour, or a white flour with the germ retained but not the bran. It is suitable for pie pastry and tarts, some cookies, muffins, biscuits and other quick breads.
Self-rising or self-raising flour is white flour that is sold premixed with chemical leavening agents and is typically composed of the following ratio:
- 100 g (3½ oz) flour
- 1½ teaspoon baking powder
- ½ teaspoon salt