*to grind cleaned and tempered wheat
*to separate the outer husk from the internal endosperm into a variety of suitable forms for customer.
Wheat is passed through a series of machines that apply the principles of particle size and density separation. Foreign materials such as metal, sticks, stones, straw, seeds and other grain are removed in steps by a magnetic separator, vibrating screens, a destoner, a disc separator and a scourer.
These are six different principles or separation normally used in wheat cleaning. These differentiations are by width, length, specific gravity, air resistance, natural peculiarity and scouring or rubbing.
After cleaning, the wheat is tempered prior to be milled. In this stage, the moisture content of the grain is increased by adding water and by allowing the grain to sit for a period of time. White flour is the ultimate product of flour milling.
The aim of white flour milling is
to extract a maximum amount of endosperm from wheat berry in as pure a form as possible. In general, 100 pounds of wheat will produce 72 pounds of flour.
The wheat is passed through a series of machines to break open the wheat kernels and reducing of the endosperm by grinding to obtain the final product – plain flour.
Most white flour is milled in high-speed steel roller mills. The grain is ripped open rather than crushed, and the germ and bran are sifted out, leaving 70 to 73 percent of the grain – the endosperm, or starch and protein.
Roller mills consist of a sequence of paired iron roller, some grooved and some smooth, that rotate inwards. Because one roller is set to spin at a faster rate than the other the grains caught in the middle are twisted and chopped.
In this process, the bran and germ layers of the grains are stripped away, leaving only white, pulpy interior kernel or endosperm.
Additives of less than 1 weight % are added to the flour by a mixing process. White flour has been enriched for years with niacin, thiamin, riboflavin and iron and folic acid is added to reduce the incidence of neural tube birth defect in developing human embryos.
Family flour for retail sale is packed in 5, 10, or 25 pound bags. Bakery flour may be packed in 50 or 100 pound bags or shipped in bulk trucks or railcars.
White flour milling
