Optical sorters are electronic machines in dry mills that clean our green coffees before export. After various steps on gravity machines to sort out unripe, defective or small screen beans, the coffee is usually checked manually on belts - but there are a few things that the human eye cannot detect.
Optical sorters take up to three photos of each bean that runs at a high speed through small tubes. If a bean looks abnormal or has shadows or holes, they will be blown out using air pressure. This process typically happens twice - using optical sorters we are able to bring secondary defects close to zero.
Two optical sorters at Los Pirineos, El Salvador