Milling wheat is one of the oldest production processes associated with human food consumption, and one of the first manual processes to be mechanized. The main phases in the milling process are grinding and sifting the wheat to separate the husk from the endosperm. For millennia, the wheat was ground using millstones. These were originally moved in circles by hand, but livestock, water or the wind were later harnessed to power the process. Sifting was done using hand sieves. For some 18 centuries, watermills and windmills. After the industrial revolution and the dissemination of electricity in urban areas, all the production gathered in industrial units, the factories, and the processing of wheat becomes with electric powered machines.