The first phase of the olive processing in the oil mill is the defoliation, which is eliminating branches and leaves that would modify the organoleptic properties of the oil negatively. The subsequent washing of the olives is a mandatory phase of the process regarding its hygiene: a meticulous removal of the remaining leaves, dirt, pebbles and other impurities is an essential requirement to guarantee the hygienic conditions necessary to produce a high quality oil. A gentle but effective washing before oil extraction also helps to protect the machinery from excessive wear and to safeguard the integrity of the fruit. The olives, in the “washer”, are washed by immersion, undergoing a continuous remixing. Frequent replacement of the washing water guarantees maximum hygiene of the product.