According to the specification of high-quality Italian extra virgin olive oil, after harvesting the olives should be pressed immediately.
It is clear, however, that for technical reasons this is not always possible because of timing and harvesting methods, the size of the plot and the waits at the olive oil mill.
In any case should not exceed 24 hours between harvesting and pressing the olives and store in layers no more than 30 cm in boxes or bins of rigid perforated plastic seats indoors and in cool and ventilated places.
This would allow to obtain an extra virgin olive oil from the unaltered taste, with a normal pH and optimum shelf life.