OLIVE oils are not shoes or even cheeses. A closet full of them, a different choice for each day of the week, for each dish on the menu, is clearly not necessary.
For most culinary uses, you will do fine keeping just two or at most three extra virgin olive oils on hand: an everyday, all-purpose oil for sautéing; a finer, more fragrant one to drizzle on a fillet of sea bass, grilled vegetables or creamy slices of fresh mozzarella; and perhaps a more robust one that can make its personality known in a bean dish, a dense soup or an assertively seasoned pasta. Any of them could be used in a salad dressing.
It has become extremely difficult to determine the country of origin of olive oil by taste, because many producers strive for the same grassy, peppery style. But here are a few generalizations, starting with the countries most frequently represented in the United States:
Italy Tuscan oils are typically greenish, peppery, with a touch of bitterness. Ligurian oils are usually lighter. Oils from southern regions like Puglia and Sicily can be warmer, sweeter and riper, with a more golden color. But the Tuscan style is also taking hold in these areas.
Spain Often produced with a sweeter, riper flavor and can have tremendous fragrance and complexity, especially when made with arbequina olives.
France Producers strive for a lighter, delicate, floral style.
Greece Some, like Wild Olives and Terra Medi, are herbaceous and peppery, but others can be flat and heavy. Oils from Crete can be fairly fragrant.
Portugal Rich and fruity, but sometimes heavy.
Turkey On the heavy side. Still often used for blending.
North Africa and The Middle East With just a couple of exceptions, like the peppery, herbaceous Tunisian oil from Les Moulins Mahjoub; the carefully nurtured Lebanese oil that is sold by Oliviers & Company; and some Israeli oils, these tend to be somewhat heavy and bland.
South Africa Often mellow, with spicy overtones.
California Vary tremendously, but many are well made, offering peppery or citrus aromas and flavors at a high price and often with a winery label.
South America Oils reflect the popular green, peppery, herbaceous Tuscan style. Olave, a newcomer from Chile that is starting to show up everywhere, is very pungent.
Australia Oils can be quite distinctive, like the pale green Njoi Red, which has the aroma of tomatoes, a gentle flavor and a lovely lightness.
New Zealand Can be herbaceous, even aggressive.