The olive is probably native to the Mediterranean region. It is long-lived and highly drought-resistant, though sensitive to frost, and thrives best at relatively low altitudes. Olives generally only crop every other year, and usually trees are regionally synchronized. Despite the attempts of farmers from antiquity to the present to break this habit, it has never successfully been circumvented.
Olives are easily propagated by cuttings, ovules (trunk growths, Gk. premna), or by grafting, a well-known technique in the classical world. Domesticated scions were frequently grafted onto wild stocks. Trees grown from cuttings planted in a nursery beds seem to have been more characteristic of Roman than Greek regimes. Greek farmers apparently preferred planting ovules, which have a greater success-rate under conditions of water-stress than cuttings. Olives do not grow true to type from seed. Many varieties were known and cultivated for both oil and table use in classical antiquity.
Rarely grown under a monocultural system, olives were usually part of mixed farming regimes, including arable and other tree crops since cropping and yields can be erratic. Sometimes olive cultivation was combined with pastoralism, as in M. Porcius Cato(1)'s (Agr.10) model olive grove which included a shepherd, 100 sheep, and a swineherd. Sheep ate grass and weed growth under trees, while pigs utilized the presscake.
Olives are harvested in autumn and winter. Greeks and Romans felt that the best-quality oil came from ‘white’ (‘green’) olives, picked early, a belief not in accord with modern practice. Ripe, ‘black’ olives contain more oil than green ones—the scarcity of oil in the latter may partially explain why it was more highly valued. Today the crucial factor is felt to be acidity, which increases in oil which is old, or which has been made from olives (black or green) stored for some time between picking and pressing.
Olives can be processed for either table-olives or oil: they are not edible raw. The most basic table-olives are packed in salt, but the Roman agronomists provide other recipes. Olive oil was used for food, medicine, lighting, perfume (see ointment), and bathing, as well as athletics.
Producing oil entails crushing, pressing, and separating. Many different devices were known in antiquity for crushing and pressing olives. The simplest crusher is a flat bed with a stone roller. However the Romans (and probably the Greeks) believed that crushing the olive stones (almost inevitable with most machines) lowered oil quality. For luxury-quality oil they tried to keep crushed stones to a minimum, although this reduced the yield. Machines were invented to achieve this end, although it is questionable how effectively they worked. The most common olive crusher found in archaeological contexts is the rotary mill generally known as the trapetum, invented around the 4th cent. bce (it is debated whether the earliest examples from Chios and Olynthus used one millstone or two). They remained common throughout the Roman world until late antiquity. See mills. The most usual presses were beam presses. Earlier examples were weighted with large stones, but later many used capstans. Screw presses came into use during Roman times, though the date of their invention is uncertain, perhaps around the 2nd cent. bce. Crushed olives were placed in bags or frails on the pressbed (many stone examples survive), and the press was fastened. The first pressing produced best quality ‘green’ oil, sometimes kept separate and sold at high prices. Hot water was poured on the frails before further, lower quality, pressings.
The mixed oil, water, and olive juice (amurca) was left to settle in vats until the oil floated. Then oil was skimmed off the top or the waste let out via a tap from the bottom. Oil was stored in large jars (dolia, pithoi) or sold in amphorae. Though most ordinary oil was probably consumed locally, high-quality oil was a luxury product traded over long distances, like vintage wine. Certain regions, e.g. Attica, Samos, Venafrum, Baetica, and Cyrenaica (see cyrene; libya), became famous for oil. In the case of Attica, the olive was an important symbol of Athena and Athens and oil from the sacred trees (moriai) was given as prizes at the Panathenaic Games (see panathenaea). However, it was probably never the most important Attic crop and oil may not have been the primary export. See agriculture; amphorae.
A. Pease, Real-Encyclopädie d. klassischen Altertumswissenschaft 17 (1937), 2454 ff., ‘Oleum’.Find this resource:
J. Hörle, Real-Encyclopädie d. klassischen Altertumswissenschaft 6 a 2 (1937), 1727 ff., ‘Torcular’ and 2187 ff. ‘Trapetum’.Find this resource:
M.-C. Amouretti and J.-P. Brun (eds.), La Production du vin et de l'huile en Méditerranée (1993).Find this resource:
A. G. Drachmann, Ancient Oil Mills and Presses (1932).Find this resource:
L. Foxhall, Olive Cultivation In Greek Farming: The Ancient Economy Revisited (1995).Find this resource:
L. Foxhall, Olive Cultivation in Ancient Greece (2007).Find this resource: