Chaff

Chaff (/ˈtʃæf/ or /ˈtʃɑːf/) is the dry, scaly protective casings of the seeds of cereal grain, or similar fine, dry, scaly plant material such as scaly parts of flowers, or finely chopped straw. Chaff is indigestible by humans, but can eat it and in agriculture it is used as livestock fodder, or is a waste material ploughed into the soil or burnt.

"Chaff" comes from Middle English chaf, from Old English ceaf, related to Old High German cheva, "husk".

In grasses (including cereals such as rice, barley, oats, and wheat), the ripe seed is surrounded by thin, dry, scaly bracts (called glumes, lemmas and paleas), forming a dry husk (or hull) around the grain. Once it is removed it is often referred to as chaff.

In wild cereals and in the primitive domesticated einkorn,emmer and spelt wheats, the husks enclose each seed tightly. Before the grain can be used, the husks must be removed.

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