After grain was removed from the straw, farmers ran it through the wheat fan twice, first through the course riddle to remove the chaff and then through the fine riddle to remove the "white caps," grains of wheat with chaff still on them, leaving only clean wheat. The clean wheat was then taken to a mill. Farmers rarely, if ever, sold their wheat; instead, they delivered it to a mill and received credit at the rate of 60 pounds per bushel. When they wanted flour, they received a certain amount of flour and bran for every 60 pounds credited to them.