Wind winnowing is an
agricultural method developed by ancient cultures for separating
grain from
chaff. It is also used to remove
weevils or other pests from stored grain.
Threshing, the separation of grain or seeds from the husks and straw, is the step in the chaff-removal process that comes before winnowing.
In its simplest form it involves throwing the mixture into the air so that the wind blows away the lighter chaff, while the heavier grains fall back down for recovery. Techniques included using a winnowing fan (a shaped basket shaken to raise the chaff) or using a tool (a winnowing fork or shovel) on a pile of harvested grain.
In China
In Ancient China the method was improved by mechanisation with the development of the rotary winnowing fan, which used a cranked fan to produce the airstream. This was featured in
Wang Zhen's book the
Nong Shu of 1313 AD. This technique was not adopted in Europe until the 1700s, when winnowing machines used a 'sail fan'.
In Greek culture
The winnowing-fan (
liknon) featured in the rites accorded
Dionysus and in the
Eleusinian Mysteries: "it was a simple agricultural implement taken over and mysticised by the religion of Dionysus,"
Jane Ellen Harrison remarked.
Dionysus Liknites ("Dionysus of the winnowing fan") was wakened by the Dionysian women, in this instance called
Thyiades, in a cave on
Parnassus high above
Delphi; the winnowing-fan links the god connected with the
mystery religions to the agricultural cycle, but mortal Greek babies too were laid in a winnowing-fan.. In
Callimachus'
Hymn to Zeus,
Adrasteia lays the infant Zeus in a golden
liknon; her goat suckles him and he is given honey.
In the Odyssey, the dead oracle Teiresias tells Odysseus to walk away from Ithaca with an oar until a wayfarer tells him it is a winnowing fan, and there to build a shrine to Poseidon.
In the New Testament
In the
Gospel according to Matthew 3.12, a sentence introduces the separation of wheat and chaff (good and bad) by "His winnowing fan is in his hand" (
American Standard Bible translation).
In the United States
The development of the
winnowing barn allowed rice plantations in
South Carolina to increase their yields dramatically.
See also
References