The olive is bitter when harvested from the tree, therefore the processing methods that we use, aim at rendering the olives non bitter and edible through fermentation.
The basic processing methods are the following:
1) The most widespread method is the Spanish (Spanish style) (Treated olives), which is based on the immersion of green olives in a 2% solution of caustic soda (NaOH) (lye) for about 12 hours. Then the liquid is removed as waste and another two washings with water take place, to remove most of the NaOH. So for every kilo of olives about 2.5 kilos of waste water are produced. These are produced every year in September and October.
About 99% of the green olives marketed in the world, are processed with the above method.
This method is not allowed to be applied to green organic olives because the use of caustic soda is not permitted by the EU Organic regulation 834.
2) Then we have the so-
3) Olives darkened by oxidation (Californian Style), are mainly green olives immersed in various alkaline solutions (again caustic soda: NaOH-
4) Dehydrated or Shrivelled natural black olives, these olives are picked from the tree when fully ripe and are dehydrated between layers of dry salt, a process that takes more than two months, the most natural way of dehydration is when the olives reach full ripeness on the tree and become shrivelled.
See.”Elaboration of table olives”