The olive tree is native to the Mediterranean region, and was probably one of the first human cultivatars: olive seeds from a site in Spain have been carbon dated to eight thousand years ago. This majestic evergreen grows about 50 feet (~16 m) tall with a spread of 30 feet (~10 m); it is tenacious, sending out shoots from a trunk which has been cut back to the ground. Olive trees take many years before they begin to fruit, but after that can live up to 500 years, and will continue to fruit even if neglected. To fruit well, however, olives need a specific climate: no late spring frosts that would kill the blossoms, a long hot summer to ripen the fruit, and enough winter chill to set the fruit. Thus it is no surprise to learn that olives are grown commercially throughout the Mediterranean region as well as in California, Australia and South Africa.
The metaphorical olive
The olive has been freighted with symbolism for centuries.
In the biblical story of Noah's ark, a dove returns to Noah bearing an olive branch in its beak, denoting prosaically that the flood was residing and metaphorically that god had forgiven humanity. This is probably why the olive branch (and the dove) symbolize peace.
An olive branch figures on many flags and emblems: the symbol of the United Nations, with the world flanked by a wreath of olive branches; the seal of the United States of America, with an eagle carrying an olive branch with 13 leaves and 13 fruit in its right talon; the flag of the League of Arab States, with a crescent encircled by an olive wreath; the flag of Cyprus, with crossed olive branches below a map of the island to represent the (uneasy) peace between the Greeks and Turks who live there; and the flag of Eritrea, with a golden olive wreath and stem. The fragility of these laudable dreams of peace is perhaps stated most baldly on the American seal, for in its left talon the eagle clutches 13 arrows, a symbol of war.
According to Greek myth, Athena, goddess of wisdom, reason, and purity, laid claim to Athens, but so did Poseidon. It was decided that whoever gave the city the greatest gift could have it. The two gods mounted the Acropolis and Poseidon struck the side of the cliff with his great trident. The residents marvelled at the spring that began gushing from that spot, but quickly found that the salty water was useless to them. Athena gave them an olive tree, and for this gift of food and oil, she was granted the great city.
The highest honour given to any citizen of Greece was an olive wreath, which was used to crown the victors of the ancient Olympic Games. In the 2004 Olympics this tradition was recalled, with the three top finishers in each competition given an olive crown in addition to their medals.
The edible olive
The olive tree is much prized for its small oily fruit with a pit, which is cured and eaten out of hand or pressed to yield a delicious oil. The leaves may be processed to yield an extract thought to have medicinal properties.
The fruit of the tree, the green drupe, usually darkens to purple when fully ripe, though some types remain green when ripened. In most varieties olives are too bitter to eat right off the tree, so the green or purple drupes are harvested and either pressed to make oil or cured in lye, brine, or salt, after which they may be packed in oil or vinegar or both.
Olive oil has been a staple of the Mediterranean diet for centuries, but only became popular in North America in the last few decades. Olive oils vary dramatically in taste, colour, and flavour depending on a number of factors, including the growing region, the variety of olive, and the way it is harvested and pressed. The very best olive oil is cold pressed, which means that only pressure is applied to the fruit to release the oil; no chemicals are used.
- Extra virgin olive oil results from the first cold pressing; it has only 1% acidity and is considered the highest quality olive oil. Though extra virgin olive oil is sold at reasonable prices in supermarkets, the really high quality stuff can cost as much as a very fine wine. If you do buy really good extra virgin olive oil, don't cook with it, because heat will compromise its flavour and colour: use it uncooked on salads or bread.
- Virgin olive oil is also first pressed, but has acidity of 1-3%.
- Fino olive oil is a mix of extra virgin and virgin, while products labelled simply "olive oil" contain a mix of refined olive oil and virgin or extra virgin olive oil.
- "Light" olive oil may be filtered to make it lighter in colour and flavour - rendering a rather nondescript product - or mixed with another oil such as canola. The only use for light olive oil in my opinion is for high heat cooking: it has a higher smoke point than other types of olive oil.
Olive oil retains its freshness for about six months, according to purists, who recommend refrigerating it if you plan to keep it longer. It will become cloudy and thick in the fridge but will return to its golden liquid state when brought back to room temperature.
North Americans visiting the Mediterranean may be shocked to see how many varieties of olives there actually are; I'll mention just a few of the more popular here.
- Those bottled green olives stuffed with pimentos, a familiar garnish for martinis, are Spanish or Manzanilla olives which have been picked when green, soaked in lye, fermented in brine for six to twelve month, and bottled in brine. They may also be sold with pits or stuffed with jalapenos, garlic, almonds etc.
- Black or Mission olives are green when ripe and gain their dark colour from lye curing and oxenygenating. They are often sold sliced, in cans, and are rather tasteless in my opinion.
- The small French Niçoise olives are ripened on the tree and then cured in brine; they are a key ingredient in Niçoise salad.
- Greek kalamata olives are also tree-ripened and cured in brine and vinegar. These strong-tasting olives are often marinated in olive oil and oregano and eaten as is, and are a key ingredient in Greek salad. They make a mean tapenade (olive paste) too.
- Dry-cured olives are a newly discovered pleasure for me. Packed in salt, they lose most of their moisture and become dry and wrinkled, after which they are sometimes rubbed with olive oil or packed with herbs. These ones are really tasty.
Once opened, bottled or canned olives should be stored in the fridge in their own liquid in a nonmetal container for a few weeks.
To pit an olive, put it on a cutting board and press with the flat of a knife until you feel the olive give a bit, then dig out the pit with your fingers. Or use a cherry pitter, if you have one. Note that this will be easier to remove the pits from dark than green olives because they are generally ripened before processing. Also, home-pitted olives will look a bit ragged.