Unfortunately, the best extra virgin olive oils are very expensive. It is an expense that no serious cook should avoid, but when paying out a king's ransom for a litre of liquid gold, take consolation from the certainty of the pleasures that await you and the comforting knowledge that premium oil of this quality will stretch a very long way and should not be wasted on frying, but kept to enrich raw or prepared dishes. And there are far more expensive flavourings, such as aged balsamic vinegar, so take heart!
In general, extra virgin oil with its rich, fruity flavour is best when you want the food to taste superbly of olives, especially in uncooked dishes, and to dress salads, soups, vegetables and cold meats. Lighter, refined oils are perfect for frying or for making more delicate dishes such as mayonnaise which the obtrusive flavour of extra virgin oil would overwhelm. The recipes will each prescribe whether extra virgin' or (refined) 'olive oil' are called for.
The colour, nose and taste of olive oil are conditioned by many different factors: the ripeness of the fruit on harvesting, the climate and soil, the hundreds of olive varieties, and so on. However, one might hazard a sweeping generalization in so far as most Tuscan extra virgin oils tend to be thick, green and smell and taste fruity, sometimes distinctly peppery, while the extra virgin olive oils of Southern Italy (Puglia, Calabria, Liguria and Sicily are the most productive regions), tend to be a paler greeny-gold, but strong to taste and smell. Of the high-quality single-estate Italian extra virgin oils, connoisseurs value particularly the Colonna, Tenuta Caparzo and Saragano brands and the famous oil marketed by the Chianti estate of Badia a Coltibuono. An excellent example of an unfiltered, farmhouse extra virgin oil is made on an estate near Florence and marketed under the label of Dell' Ugo. This has a robust peppery taste and a wonderfully natural cloudy, green colour. These are all premium quality uncommercial oils equivalent to the grands crus wines, but if you cannot obtain them, there are many other good commercial extra virgin oils, including the well-known brands Berio, Sasso, Menucci and de Cecco.
Although ranked low on the world's production tables, the olive oils of Provence are esteemed and widely available. Although mostly golden or yellow in colour, some of the finest extra virgin oils are distinctly green, including those that are produced in the Valley of Les Baux, and the commended Le Vieux Moulin label from Nyons. These and oils from neighbouring Nimes are widely acknowledged to be the best in France. Good quality commercially made blends of Provençal oils that you are likely to encounter include the brand names Plagniol and A l'Olivier, which has a marvellous specialist shop in Paris. A visit to the Alziari shop at 14 Rue St. François de Paul is recommended to any oleophile who may be passing through Nice.
Spain vies with Italy as the world's largest producer, and this is where my favourite everyday, mass-produced oils come from. On the infamous occasions when adulterated oils tragically have poisoned many hundreds of unsuspecting people, these have always been traced to cheap oil tainted with industrial compounds unfit for human consumption, sold door-to-door in unmarked containers by unscrupulous travelling vendors. In fact, the record of the leading commercial brands, including Carbonell and Ybarra, is impeccable and you need have no worries about buying any of the Spanish olive oil you will find on sale. Lerida in north-east Spain is considered the finest oil-producing region, with delicate, straw-coloured oils which have gained quite a following amongst the cognoscenti. The Lerida brand, shown on the cover, is an extra virgin olive oil made exclusively from the Arbequina olive, which has won several medals and accolades of late. But Spain's largest and most productive provinces are Jaen, Cordoba, Malaga and Granada, all in Andalucia, and it is mostly these oils that go into the blends of the household brands. Greek olive oil is generally of good quality and represents particularly excellent value for money. On Corfu and in other traditional Greek rural communities, the family olive trees are still both master and servant, compelling many back-breaking hours of toil collecting the fallen olives from a ground that has been draped with black nylon nets. The olives are usually sent away to be crushed in a communal mill. The ensuing oil will be used not only for cooking, but also for anointing babies at baptisms, mixed with lime to produce domestic whitewash, poured into uncorked wine bottles to seal the remaining wine from contact with the air, and poured over shallow waters to reveal with gin-like clarity the whereabouts of shoals of fish, squid and octopus. Left-over oil from cooking will be discreetly collected by the representative of a leading cosmetics company, to make soap. With so many applications, no wonder these canny country folk have chosen not to sacrifice their precious olive groves on the altar of tourist development and hotel construction. Greece is the world's third largest producer of olive oil and one of the largest consumers, with a staggering per capita consumption of 25 litres a year. Cultivation is intensive, albeit on a reduced scale, based at many small farms, co-operatives and small holdings, in complete contrast with Spain's vast tracts of terrain planted with olives, owned by the large commercial manufacturers. Koroneiki olives grown on the Mani peninsula produce the finest extra virgin olive oil in Greece.
Portugal, Turkey, Morocco, Tunisia, Algeria, Libya, Syria, Jordan and the Lebanon also produce good quality olive oil, employing traditional methods, and other, more marginal producers include Egypt, Iran, Yugoslavia, Albania, Israel, Peru, Chile, Brazil, Argentina, Mexico and California.
The appreciation of quality oils has become quite a serious subject for study and has attracted the attention of food writers and critics. This has resulted not only in the adoption of an oil parlance every bit as quaint and fanciful - some would say pretentious - as that applied to wine, but also in promotional olive oil tastings. Traditionally, oil, like wine, is assessed by its appearance, smell and taste. Usually olive oils are tasted on small pieces of plain white bread, which are the perfect neutral backdrop to the taste of the oils. The colour can be verified by pouring different oils on to unpatterned white dishes. Country people and olive growers also judge the quality of olive oil by pouring a little on to the back of the hand and gently rubbing it in, then inhaling the aroma. In Italy, tasters decked out in laboratory coats are employed by the regulating authorities to check and classify oil. Their method is that of the wine taster: a swirl in the glass and a holding up to the light to check colour, another swirl, a good, deep sniff, then a mouthful.
Olive oil can be heated to higher temperatures before burning than nut and seed oils which are high in polyunsaturates and is thus an excellent frying medium or one in which to quickly sear meat, poultry or meaty fish, sealing in the juices. However, once the oil has really smoked, it is best not to re-use it, as potentially harmful chemical changes occur in all oils at such high temperatures. Do, however, save oil in which aromatic or pungent ingredients such as garlic or chillies have been gently simmered, as these will deliciously flavour food subsequently cooked in that oil. Never pour hot oil back into the bottle, especially if the container is plastic. Instead keep a separate glass or ceramic container handy. Olive oil can be restored to its original clarity once filtered through paper towel and after a sprig of parsley or a piece of lettuce has been simmered in it. However, it is best not to re-use it more than twice, as the more times it is used, the more likely it is to smoke and the less effective are its nutritional benefits. To deep-fry most ingredients, especially battered, breadcrumbed or floured fish, meat or vegetables, and french fries, make sure the oil is very hot and the ingredients are completely dry and not too cold. Really hot olive oil will form a film around the food and prevent too much oil from being absorbed by it. Extra virgin oil will impart its flavour in marinades and when drizzled on to barbecued foods before they are fully cooked. One of my favourite cooking techniques is to cook meat, fish or poultry, which has rested for some time in a bath of seasoned extra virgin olive oil, on a Spanish cast-iron hot plate, or griddle, called a plancha.
Infusions of olive oil and herbs or spices are fun to make, decorative and taste wonderful and some suggestions are given on pages 64 and 65. For a real gourmet experience, try to find some truffle-flavoured oil: the combination of premium extra virgin olive oil and truffle must make this one of the most luxurious and expensive flavourings in existence.
With its assertive flavour and ability efficiently to displace air, olive oil is also the perfect preserving medium, and many vegetables as well as wild mushrooms and sun-dried tomatoes are traditionally sterilized with pickling spices in a weak solution of watery vinegar, before being preserved sott'olio (lit-erally: 'under the oil). Some recipes for preserving in oil are given on pages 61 to 63.
Extra virgin oil is a wonderful flavouring for all manner of foods, whether to anoint wafer-thin slices of bresaola (cured beef), or to add to soups, salads and vegetables. No table in Spain, Portugal, Italy, Greece or Provence would be complete without an olive oil dispenser to refract the light in a gentle pool of greenish gold.