The harvesting of the olives is a very delicate operation. To ensure the highest quality of olive oil you have to concentrate on the maturity of the olives, and the method of harvesting them.
The olives mature at the late fall. The best time to be harvested is when they turn from green to black. At this time they contain the most oil and the best quality.
It is known that the olives don’t all mature at the same time. Years ago when I was growing up in Greece, my parents used to pick the olives several times from each tree.
Now, and especially on larger olive farms, that isn’t economical, and they harvest the olives when most of them are matured. To wait for all the olives to mature, leads to the production of oils with high levels of acidity. That kills the top quality of olive oil, the extra virgin olive oil.
The best quality of olive oil and best quality of olives served at the table, depends also on the method of harvesting. They should be picked from the tree and not from the ground.
The simplest and most common technique, is hand picking the ripe olives from the tree. It usually gets repeated a few times from the end of fall to the very end of winter. This method is used for the small olive trees. The pickers use a hand-held rake, that can reach the highest branches.
Another method is for the bigger trees. The pickers use poles to beat the branches.
The olives are caught on thick canvas sheets (liopania), that are placed on the ground, under the trees. Hand picking is a must for the rough land (steep hills and rocky uneven grounds) and believe me, there are plenty of those in Greece.
Another method is, mechanically picking the olives. This method of tree shaking machinery, has reduced the number of people that are needed to harvest the olives. The use of this machinery is limited to the olive orchards that are flat and the trees are spaced apart.