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Tuscan Olive Oil - growing olives in Italy
by Jonathan Arthur of Italy with Relish

Olive treeOlive trees are not native to the Italian peninsular, being imported by the Ancient Greeks when southern Italy was part of their empire. Even today olives are mostly found to the south west of the Apennine ridge, the north being too cold for them to survive except in areas close to the larger lakes where the presence of a large body of water inhibits harsh frosts. Even in Tuscany, when the temperature falls to five degrees below (Centigrade), especially after a warm spell in late winter, a large proportion of the trees will die above ground level. The last big freeze was in 1985, then the affected trees were cut off at the base of the trunk and of the resulting suckers, three or four of the strongest selected to grow into the multi trunk ones we often see today. The climate in this area in not a natural one for the plant, so all those that grow have been planted, there are no wild olives trees.

Within Italy and around the Mediterranean there are many different sorts of olives and ways to harvest them. Leaving aside olives for eating, those for oil can be collected in various ways. Where summers are longer and warmer it is enough to spread nets below the trees and wait for nature to take its course, in cooler climes a little help may be needed, shaking the trees or the individual branches. In Tuscany and Umbria, which are at the northern edge of oil production, the fruit never matures enough to fall from the tree and so has to be hand plucked or raked into net and baskets. This inevitably leads to higher production costs, which, according to aficionados, is justified by a higher quality.

Before going into the relative merits of the various olive oil producing areas it is important to know how it differs from other edible oils and the way it is produced. Almost all other oils are made by first reducing the oil bearing seed into a pulp, then the oil is dissolved out by a spirit which, when separated from the water and solid matter, is then evaporated off leaving the oil. Olive oil on the other hand is made from a purely physical, as opposed to chemical, process and avoids heating which would change its taste.

Multi trunk olive tree Olive trees

The particular peppery taste of good fresh olive oil comes from the alkaloids contained in it, in the same way that an unripe apple tastes different from a mature one so the immature olives of central Italy produce an oil with a taste much more pronounced than those left to ripen and fall. Though many other olive producing areas will be justly proud of their product it is universally accepted that a lower level of acidity is an indication of better oil. It is the acidity caused by the oxidization of oil, turning it into a fatty acid, that kills off the alkaloid and hence the flavor. (Just the same as lemon juice or vinegar will tone down the heat of chili pepper). In fact olive oil, to be classed as a virgin has to have an acidity of below 2%, to be classed as extra virgin less than 1%. The best Tuscan and Umbrian extra virgin oils have acidity of less than 0.01%, almost unheard of elsewhere. This makes them particularly good for use in Bruscetta, on green vegetables, and of course on the rich meat and bean dishes of the area. (It has to be said that for delicate fish dishes, a lighter condiment is probably more appropriate.)

Producing olive oil Producing olive oil

Over the last century the methods of producing olive oil has evolved leading to some confusion in terms. An olive has three main constituents, the solid matter in the pip, skin, etc - Sansa in Italian - the water content with various substances in solution and the oil itself. To divide these the olive is first reduced to a paste. In the more traditional mills this is done by giant stone wheels rolling over and over it, these days' mechanical hammers are more the norm. Next the liquids are separated from the Sansa, again in more traditional mills this is done differently, by a hydraulic press; more modern ones use a centrifuge, some times two in series. Finally a centrifuge separates the two liquids leaving the pure oil. When centrifuges were first employed to separate the sansa they were not very efficient and so hot water was injected into the mix to make the oil less viscous and easier to separate, this process is no longer in use so all oils are cold press.

Olive oil on breadThe remaining solid matter still retains some olive oil which can be extracted by the chemical system used for other oils. In Italy when this is done the result is called "Olio di Sansa" and in some countries also, once treated, sold as rectified olive oil, or just olive oil the result of the second press. All "Olio di Oliva" from Italy is first press.

The much prized new olive oils, normally unfiltered, have a perfume and flavor much more intense than when kept for some months. Though storing out of the light and at a constant cool temperature will help to keep it fresh, there is an inevitable decline in fruitiness over time. Only recently has this oil been appreciated and available outside of Italy though more cooks and food lovers are discovering it and its uses.

Written by Jonathan Arthur
Italy with Relish

© Copyright 2007 Jonathan Arthur - www.italywithrelish.it

Published 12 November 2006

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