Lesung, Alu, and Padi

Lesung is a traditional tool used in processing unhusked rice or grain into white rice. Its function is to mechanically separate the grain husk (chaff, Javanese merang) from the rice grains.

The lesung itself is essentially just a concave vessel, typically made from a large log with its core hollowed out. The grain to be processed is placed into this cavity. The rice or grain is then pounded repeatedly with an alu (a thick wooden pole) until the rice grains separate from the husk.