Retting

Retting is a process employing the action of micro-organisms and moisture on plants to dissolve or rot away much of the cellular tissues and pectins surrounding bast-fibre bundles, facilitating the separation of the fibre from the stem.

Waste retting water, which requires treatment to reduce harmful toxic elements before its release, is rich in plant minerals, such as nitrates, and can be used as liquid fertilizer.

The harvested plant stalks are spread evenly in grassy fields, where the combined action of bacteria, sun, air, and dew produces fermentation, dissolving much of the stem material surrounding the fibre bundles.

The retted stalks, called straw, are dried in open air or by mechanical means, and are frequently stored for a short period to allow "curing" to occur, facilitating fibre removal.

The short fibre or tow thus obtained is frequently used in paper manufacture, and the shives may serve as fuel to heat the retting water or may be made into wallboard and to make rope.