Flour is a powder that is finely ground. It is used in baking and is prepared from starchy plant foods such as grain. Flour can be produced from a wide variety of plants but the vast majority is made from wheat. The production of flour dates back to prehistoric times. The earliest methods used for the production of flour involved grinding grain between stones. Different ways of doing so included methods such as the ‘saddlestone’ (a cylindrical stone rolling against grain contained in a stone bowl), the ‘quern’ (a horizontal, disk-shaped stone spinning on top of grain held together by another horizontal stone) and the ‘mortar and pestle’ (a stone club striking grain that was placed inside a stone bowl). These three different methods were all achieved by hand.
Today, wheat must meet certain specifications when it comes to delivery and storage. This is dependent on the moisture content of the wheat along with its specific weight and variety as well as its protein content and quality. Powerful magnets, metal detectors and other machines are used to clean the wheat and to extract other grains from the wheat (such as oats, barley and small seeds). Air currents lift off any unwanted dust during the cleaning process. Once it has been cleaned, the wheat is then conditioned with water, which is then followed by a process known as ‘gristing’. Gristing is a necessity when it comes to making different types of flour. Occasionally, wheat gluten is added in order to increase the protein content of milled flours. Milling involves breaking, sifting and rolling the flour in order to achieve the right colour and consistency. The grist is passed through a series of fluted ‘break’ rolls which all rotated at different speeds. These rolls are set so that they shear the wheat open without cutting it in order to completely separate the white, inner portion and the outer skins. The different fragments of the wheat grain are split up by a complex arrangement of sieves.
The type and colour of the flour depends on when it is rolled. Whiter flours are made from the early reduction rolls. The later rolls result in darker flours. Brown flour, for example, consists of white flour and a portion of the other streams all mixed together. Each type of flour is packaged up before being distributed to the bakeries. Bakers use flour to make bread as well as other foods such as cakes and pies. Flour is an essential ingredient to many foods and is an absolute necessity when it comes to baking.