The grain – each grain of wheat is made up of three parts, the coarse outer bran layer, and inside this, the germ and the endosperm. The endosperm is the starchy food store of the grain.
The milling process
Mills have been making flour for thousands of years. Flour is made in nearly every country in the world. In the past, wheat was ground between huge millstones in windmills or watermills but the flour was coarse. Today’s flour is much finer because the process uses modern technology.
- Cleaning wheat – first the wheat is cleaned. It passes through magnets and metal detectors to remove any metal. Machines separate any other seeds, stones or dust that may have got mixed with the wheat.
- Conditioning wheat –
- Gristing wheat – The cleaned and conditioned wheat is blended with other types of wheat in a process called gristing. This means mixing different types of wheat in different proportions to make different kinds of flour.
- The gristed wheat passes through special rollers called break rolls. They break each grain into its three parts: wheat germ, bran and endosperm.
- Sieves sift the three separated parts into different streams.
- The endosperm particles pass through smooth rollers called reduction rolls to make white flour. White flour has had the bran and germ removed so it makes lighter bread.
The bran, wheatgerm and endosperm have all been separated out. They can now be blended to make different types of flour.
- Wholemeal flour uses all parts of the grain.
- Brown flour contains about 85% of the original grain, but with some bran and germ removed.
- White flour is made from the endosperm only.
The different flours are then packed and sent to the bakeries. The flour is used for many types of bread as well as biscuits, pies, cakes and confectionery.
Did you know that as well as being made from wheat, flour can be ground from other crops such as maize or rice.