Winnowing

Rice winnowing in India.

Winnowing is a farming method developed by ancient people for separating grain from chaff. It is also used to remove weevils or other pests from stored grain. Threshing, which is the loosening of grain or seeds from the husks and straw, comes before winnowing. In place of a winnowing basket a colandar can be used.

In its simplest form it involves throwing the mixture into the air so that the wind blows away the lighter chaff. The heavier grains fall back down for recovery. This method is called "wind-grading".^[1] Other methods include using a winnowing fan (a shaped basket shaken to raise the chaff).^[2] Yet another is using a tool (a winnowing fork or shovel) on a pile of harvested grain.

Winnowing can also describe the natural removal of fine material from a coarser sediment by wind or flowing water. This is similar to separating wheat from chaff.

Winnowing Media

Rice winnowing, Uttarakhand, India
Winnowing in a village in Tamil Nadu, India
Use of winnowing forks by ancient Egyptian agriculturalists
Chinese rotary fan winnowing machine, from the Tiangong Kaiwu encyclopedia (1637)
Le vanneur (The Winnower) by Jean-François Millet, a 19th-century depiction of winnowing by fan
Winnowing machine from 1839

References

↑ H. J. Hopfen, Farm Implements for Arid and Tropical Regions (Rome: Food and Agriculture Organization of the United Nations, 1981), p. 130
↑ Joseph Needham, Francesca Bray, Science and Civilisation in China, Volume 6 (Cambridge: Cambridge University Press, 1986), p. 375

[Hopfen130-1] H. J. Hopfen, Farm Implements for Arid and Tropical Regions (Rome: Food and Agriculture Organization of the United Nations, 1981), p. 130

[2] Joseph Needham, Francesca Bray, Science and Civilisation in China, Volume 6 (Cambridge: Cambridge University Press, 1986), p. 375

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