The fruit of the olive tree, Olea europaea, and the oil which it yields (see olive oil), foods which originated in the Mediterranean region, are often thought of as symbolizing it.
The importance of the olive tree and the veneration which it has aroused since prehistoric times are widely attested, for example by the use of the olive branch as a symbol for peace. Biblical, classical, and other literary references abound. Lawrence Durrell wrote in Prospero's Cell that the whole Mediterranean ‘seems to rise in the sour, pungent taste of these black olives between the teeth. A taste older than meat, older than wine.’
It is not only in literature that the trees and their fruits have been memorably portrayed. Maggie Blyth Klein (1994) remarks on the manner in which the Impressionist painters captured their spirit, and in how many different ways.
Olives from wild trees (oleasters) were sporadically gathered, in the Near East, by neolithic peoples about 10,000 years ago. The small, bitter fruit of the oleaster contains more stone than flesh. The tree began to be cultivated, perhaps in Palestine or Syria, well before 3000 bc, and in the following three millennia olive farming gradually spread to Anatolia, Crete, Greece, Italy, S. France, and Spain—and also eastwards to C. Asia. Archaeologists find not only the discarded stones of the fruit but also the remains of olive mills and presses. Oil storage jars are found in large quantities: these often travelled long distances by sea.
To both Greeks and Romans the olive was a crop of the first importance. Athenians claimed the first olive tree, given to mankind by the goddess Athena and growing on the Acropolis. To destroy an enemy's olive trees was a sacrilegious act and a demonstration of ruthlessness in war. Cato's manual On Farming, the first Roman prose text (c.175 bc), devotes more space to olive-growing and oil-making than to any other topic.
The olive is an evergreen with foliage of a distinctive silvery-green. Deep rooted, it is slow to mature and very long-lived: olive-growing regions can show gnarled old trees reputed to be many hundreds of years old and still fruiting reliably. It is susceptible to severe cold: the frosts of 1870 and 1956 are blamed (along with foreign competition and cheap vegetable oils) for the steep decline of the olive industry of Provence. Olive trees are grown in valley meadows and on hillside terraces, an unmistakable feature of the Mediterranean landscape.
The northern limit of olive cultivation remains a major landmark across Europe and W. Asia. However, in recent centuries olive-growing has spread far beyond these traditional regions.
Only a small proportion of the olive harvest is processed as table olives, and around 70% of these are consumed by those living around the Mediterranean Sea and in Middle Eastern countries.
Olives intended for preserving and table use (or use in cookery) are harvested at various stages of ripeness with very different results in texture and flavour.
Unripe olives are green, very bitter, and with firm flesh. Their flesh is often cracked, by a gentle blow with a mallet, to allow water and marinades to penetrate. As the olives ripen they become oilier, and their colour changes from green to purple. Fully ripe, black olives are oilier still, soft in texture, and relatively free of bitterness.
Methods of curing olives for table use vary considerably according to the degree of ripeness and from country to country. Lourdes March and Alicia Rios (1988), in a remarkable essay with a considerable historical as well as technical content, have made the point that the various preparation and preservation processes have been carried out for a very long time in Spain by people who have no technical knowledge of the chemical phenomena which take place during them.
Nevertheless, the know-how acquired from their parents enables the country folk to recognize when the olive has reached the appropriate stage at any point in the proceedings, whether the process to remove the bitterness, the fermentation period, or the seasoning procedure. They can also calculate the proportions of the ingredients without having to measure them, ending up with top-quality olives which taste absolutely exquisite.
The complexity of this inherited wisdom is obvious from even a bare list of the techniques which may, separately or in combination, be applied:
Green olives must be first treated in lye (2–3.5% solutions) to eliminate the bitter component, oleuropein, and then thoroughly rinsed. Spanish or Sevillian-style olives, typically Manzanillo and Gordal varieties, undergo fermentation in brine solution for 2–3 months. This fermentation, besides having a preservative function, breaks down the sugar that olives contain into lactic acid, thus contributing to their flavour. These olives are often stoned and stuffed with strips of red pepper, almonds, onions, anchovies, or garlic.
The Picholine olives which are particular to S. France are not fermented, spending only 10–12 days in brine. In this way they retain their firm flesh, vivid green colour, and intense flavour. The varieties processed in this way are Picholine and the slightly larger Lucques, sometimes considered the best green table olive in the world. Semi-ripe olives, picked when their colour is starting to change, are treated in a similar way with a weak lye solution followed by brine.
Black olives, being fully ripe, need only to be brined or, for the purplish-black Greek Kalamata olives, slit laterally and treated with vinegar and brine. If overripe, they can be dry cured by packing in alternating layers with salt; the resultant olives are shrivelled, wrinkled, and salty. The Italian Gaeta olives and French Nyons olives are commonly prepared in this way.
The California black ripe table olive, which is unique to California, is produced in a different way from those from the Mediterranean. Picked green and immature, the olives are soaked in an aerated lye solution to eliminate the bitterness and turn the fruit black; if air is not added, the olives remain green. After rinsing, ferrous gluconate is added to promote uniformity and stability of colour.
The flavour of olives can be greatly improved by the use of herbs and spices which are usually added to the brine to form marinades of almost infinite variety. Out of the brine, they can be further enhanced with dressings of olive oil plus herbs, garlic, orange peel, fennel, and other seeds.
Stuffed olives are popular, and have a fairly long history. As early as the 18th century, producers of some of the olives of Aix-en-Provence, such as the famous Picholine variety, were stoning their olives and replacing the stone with capers, anchovies, tuna, pimiento (see capsicum), etc.
Industrial methods of preparation result in olives that will keep longer, typically marketed in jars or tins. Olives in glass jars were first sold in 1898 in Oroville, California; Frederic Bioletti, also in California, developed olive-canning in the early 1900s. However, it was not until 1933 that a Californian mechanic, Herbert Kagley, built the prototype of the first mechanical olive pitter which could be used successfully to pit green olives for use in martini cocktails.
Andrew Dalby has written essays and books about food in classical times, especially Siren Feasts, on food and gastronomy in classical Greece.
Barbara Santich is responsible for the Graduate Program in Gastronomy at the University of Adelaide and the author of six books, including The Original Mediterranean Cuisine. Her research interests focus on France and Australia.
Klein, Maggie Blyth (1994), The Feast of the Olive, rev edn, San Francisco: Chronicle Books.
March, Lourdes and Rios, Alicia (1988), ‘Oliva Sapiens’, in Taste, Oxford Symposium on Food History 1987, London: Prospect Books.
Rosenblum, Mort (1997), Olives, Bath: Absolute Press.
Visser, Margaret (1986), Much Depends on Dinner, Canada: M. & S.
