The origins of the olive tree and its fruit (drupe) are lost in the mists of history.
Researchers established eastern Mediterranean people had cultivated the olive tree sine before biblical times. Everything the olive tree produces is used, including the trunk, once the tree no longer shows any sign of life.
Olive trees are long lived. Some are more than 1000 years old, but are very sensitive to cold. Old trees produce little, but very flavourful olives, much like vines. Thousands of olive cultivars thrive in different parts of the world. The same cultivar grown in two regions (terroirs) yield completely different olives, both in taste and mouth feel.
Although most olives are processed into olive oil, many are cured and sold for out of hand eating, or as paste in tubes.
Some green olives are stuffed with pimento.
All olives turn dark brown or purple when ripe. Green olives, which have a stronger taste and crisper in texture, are picked unripe. Freshly picked olives are too bitter to eat and must be soaked in lye or brined or salt cured. After curing, they are packed in olive oil or in weak vinegar solution, or shrink-wrapped.
Brining requires soaking olives for several weeks in order to leach out the bitter taste. After that, they may be marinated with herbs and packed in olive oil or vinegar.
Salt curing occurs in containers with layers of salt.
This process yields shrivelled olives that are either packed in olive oil or in a weak vinegar solution or sold in bulk.
Olives come in jars, pitted, stuffed, and sliced, in paste form.
Italian, Middle Eastern, and European delicatessen stores carry adequate inventories of a range of olives.
There are hundreds of olive species.
Below, find some that are popular in Western Europe and North America.
Ceriguola, from Puglia, Italy, are very large, and best for stuffing.
Arbequina, Catalonia in Spain, is smaller than ceriguola, and yields fruity and delicate olive oils.
Beldi olives originate in Morocco, and are often pitted and packaged in jars for western markets. This green olive is sold in bulk in Moroccan markets.
Kalamta, Greece, originated in that sunny country and has been replanted elsewhere in the world, but those from Kalamata taste best. Always marinated in red wine vinegar then packed in olive oil, they are very tasty.
Gaeta, Italy is best for eating.
Sevillano, originated, in Seville, Spain, and is now also grown in California. Large in size, it is often sold stuffed with pimentos. The flavour is mild, but the texture is crisp.
Frontoio, from Tuscany, Italy, tastes fruity with a strong almond flavour.
Leccino, from Tuscany, Italy is mild and sweet, and mostly used for olive oil production Manzanilla, originally from Spain, is now grown in California, Australia, and New Zealand. It is large, and lends itself well for stuffing and slicing. Sliced olives, at least in North America, are mostly used for pizzas.
Picholine, from southeastern France, is a small but very flavourful olive, suitable for out of hand eating.
Nicoise, from France, is a small black olive grown around the city of Nice. Processors often marinate it in Provencal herbs, or salt-cure.
For salad dressings, use extra virgin olive oil with less than .05 acidity, for frying virgin olive oil will suffice. Do not use lampante olive oil in food.
Regular olive oil is too high in acidity and thin.
Keep olive oil in a cool, dark place and use it within a year. Unfiltered olive oil tastes better, but should be consumed within eight to 10 months after packaging.
World olive oil production is more than 19 million tons, of which Spain produces more than seven million, followed by Italy, Greece, Turkey, and Argentina.
The U S A, Chile, New Zealand and Australia produce olive oil, but in relatively small quantities.