A flour dresser is a mechanical device used in grain mills for bolting or flour extraction which is the process of separating the finished flour from the other grain components following milling. The milling of grain into flour has been termed the oldest continuously conducted industry in the world. Flour dressers appear in water-powered mills in the United Kingdom dating to the 17th century and their use continued into the 20th Century in the UK and other countries as the grain milling industry converted from water power to steam and other forms of power to drive mill machinery.