A Guide for the Perplexed Olive Oil Buyer

1. What is extra virgin anyways?
Traditionally produced extra virgin oils, made from the first pressing of olives, are essentially little more than the juice of the olive. Technically, "extra virgin" is a grade of olive oil—usually indicating the highest quality and distinguished by its naturally low levels of free oleic acid. To qualify as "extra virgin," an olive oil must have a free acid count of less than 1 percent, be totally free of any defects, and score positively for fruit and other desirable attributes. Select oil from the most recent harvest season (which goes from November to February) and consume quickly once the bottle is opened.

2. Is cold-pressed olive oil better?
Usually, yes. "Cold-pressed" refers to the technique used to extract the best oil from the olives. To get the highest quality oil, the presser cannot use any heat. To accomplish this feat called cold-pressing, quality oil producers crush their olives with stone wheels (millstones, or pietre in Italian). Although other methods may work more quickly and yield more oil, the friction caused can damage the quality and flavor of the oil. Cold-pressing is one sign that a producer is trying to make a good oil. But as with the "extra virgin" label, there are oils labeled "cold-pressed" made from mediocre olives that aren't particularly flavorful. So the name alone is not enough. The bottom line, again, is how it tastes.

3. How long can you store olive oil?
Olive oils' most pernicious enemies are heat and light. As a rule, extra virgin olive oil can generally be stored for about a year as long as it is kept in a relatively cool, dark place, but not in the refrigerator. Be sure to stay away from windowsills and stove sides. Because it is so low in free acidity—remember, extra virgin oil has less than 1 percent acidity—it is less likely to go rancid than a lesser oil; lower grades of oil, like the lower grade "olive oil" sold in the supermarkets, have higher acidities and tend to spoil more quickly.

4. What is the best way to use extra-virgin olive oil?  Extra-virgin olive oil is primarily a condiment. It is the condiment value that you are paying for when you buy a bottle. Since heat destroys the taste (that value), it is best used cool. Drizzle, mix or blend on foods that have either been cooked (pasta, steamed vegetables, popcorn, corn on the cob, etc.) or that you plan to eat uncooked (salad, tomatoes, etc.).