Chaff

The process of loosening the chaff from the grain so as to remove it is called "threshing" before "drying" – traditionally done by milling or pounding, making it finer like "flour". Separating remaining loose chaff from the grain is called "winnowing" – traditionally done by repeatedly tossing the grain up into a light wind, which gradually blows the lighter chaff away. This method typically uses a broad, plate-shaped basket or similar receptacle to hold and collect the winnowed grain as it falls back down.^[5]

Domesticated grains such as

Chaff should not be confused with bran, which is a finer, scaly material that is part of the grain itself.

Straw chaff

Chaff is also made by chopping straw (or sometimes coarse hay) into very short lengths, using a machine called a chaff cutter. Like grain chaff, it is used as animal feed and is a way of making coarse fodder more palatable for livestock.^[6][7][8]

Coffee chaff

Coffee chaff is produced from the so called silverskin, the thin inner-parchment layer on dried coffee beans, in the process of

Botany

In

Chaff as a waste product from grain processing leads to a metaphorical use of the term, to refer to something seen as worthless. In the Bible, such use is found in Job 13:25,^[10] Isaiah 33:11,^[11] Psalm 83:13-15,^[12] and other places. Chaff also lends its name to a radar countermeasure, composed of small particles dropped from an aircraft.^{[citation needed]}

Use

Hungarian engineer László Schremmer has discovered that the use of chaff-based filters can reduce the arsenic content of water to 3 microgram/litre. This is especially important in areas where the potable water is provided by filtering the water extracted from an underground aquifer.^[13]

See also

• Awn (botany)
• Bran
• Biomass
• Combine harvester
• Rice hulls
• Rice huller

References