Traditionally coir fibre is extracted from coconut husk by a process known as retting. Retting by the conventional methods takes 6 to 10 months. The new process developed relates to reducing the period of retting of coconut husks and upgrading the quality of unretted green husk coir fibre treatment by treatment with a combination of bacterial cultures. The conventional method of coir extraction from coconut husk is presently done in two ways.

Method I: Dehusking is done by mechanically removing of the fibres from the husks, which is labour intensive. This method is followed in Tamil Nadu and parts of Kerala. The coir obtained by this method is rough and sells for a lesser price.

Method II: In this process, about 5000-8000 husks are tied together and soaked in backwaters for a period of 7-11 months. After this period, the fibre from husk is removed easily. The fibre obtained by this method is far superior and fetches more value. This method of retting takes longer time and results in release of phenolic compounds, which pollute the backwaters.

Treatment with Coirret: The coirret is a consortium of microbes and is applied directly to coconut husk in RCC tanks similar to that being done in the backwaters of Kerala. Coirret is applied to coconut husks @ 4 kg per 5000 husks in two instalments of 2 kg. The first addition is carried out one week after steeping of husks and the second, one month, after the first addition. The fibre is extracted after three months of steeping. In this method, the retting time is reduced from 7-11 months to 3 months only and the quality of fibre is the same as natural retted fibre obtained from the backwaters.

Coirret can ret machine extracted unretted coir fibre in baled form stacked in RCC tanks and immersed in water to yield a fibre of quality comparable to the retted fibre in 72 hours. The Retting effluents generated during the retting of coconut husks contain phenolic compounds and pollute the environment. An effluent treatment system has also been developed for disposal of the effluents.

The coirret is maintained in a viscous medium packed in polythene packets, which have to be kept preferably under refrigerated conditions. It has a shelf life of 30 days at room temperature. The cost of retted fibre by treating with coirret is Rs.11.00 per kg and the selling price is Rs.38.00 per kg.