Olive oil is ranked by international organizations, like the International Olive Oil Council, according to how it is produced as well as its acidity. Because olives are a fruit, the less that olive oil is handled, the better the final product is.
The primary types of olive oil are:
Olive oil is central to the Mediterranean diet. Some specialists say the diet is particularly healthy because people who live in the Mediterranean region generally eat more grains, nuts, legumes, vegetables, fish, and olive oil than people in other regions. Lower cardiovascular disease around the Mediterranean is associated with this type of diet. In any case, olive oil is a monounsaturated fatty acid rich in antioxidants. It does not have the same cholesterol-raising effects of saturated fats.
Unlike basic cooking oils, premium olive oil requires some tender loving care. Its primary enemies are air, heat, light, and age. Any of these alone or in combination causes the oil to break down and turn rancid.
Keep the oil in an airtight container, don't leave it sitting out where sunlight will heat it, and use it or lose it. As it ages over several months and is exposed to air, oxidation causes the oil to break down and eventually become rancid.
A bottle being used daily should be stored where the temperature ranges between 50° and 60°F. For long-term storage, olive oil keeps very well in the refrigerator. Instead of keeping just one large bottle in the refrigerator, keep one small glass bottle in the cupboard for easy daily use and the rest in smaller airtight glass bottles in the refrigerator.
Extra-virgin olive oil is ideal for salads and vinaigrette dressings. Drizzling some oil over vegetables just before you serve them will add visual and taste sparkle. Try it over asparagus or eggplant grilled on the barbecue. And, of course, crunchy bread dipped in olive oil is a slice of heaven.
But don't waste the extra-virgin oil in a skillet when you are frying food. For that, the light or extra-light olive oil will serve you better because it has a higher smoking point.