Abstract: An automated wet sieving apparatus and process are provided comprising a wetting liquid distributor which is coupled by eccentric disks to a motor which drives the distributor in an orbital path for supplying the liquid onto a sieve. Means are provided for creating alternating vacuum and pressure below the sieve. The vacuum draws undersized particles whose size is being determined through the sieve and the pressure loosens blinding particles from the sieve. Preferably, the sieve is cyclically tilted as the wetting liquid is being distributed onto the sieve.