What is Extra Virgin Olive Oil?
Extra virgin olive oil is the oil extracted from fresh olives using a mechanical process without the use of excessive heat or any form of additives or solvents. The olive oil, in order to be classified as extra-virgin must meet both a sensory (taste) and chemical analysis. From a chemical perspective, the olive must have less then .8% of free-fatty acid. From a sensory perspective, the olive oil must be free of any tasting “defects” such as the taste of crayons, the smell of plastic, or a greasy-mouth feel.
 
How long can I expect my extra virgin olive oil to last?

Extra virgin olive oils are best consumed as close to the date it was made as possible. The fresher the oil, the better aromas, flavors and higher polyphenols (anti-oxidants) that are present. Unlike wine, olive oils do not get better with age, so the closer to their crush date that you purchase and use them, the better.

However, the higher levels of natural antioxidants and the higher proportion of monounsaturated fats generally found in extra virgin olive oil mean that they generally remain fresher longer than other edible oils.

As a guide, provided they are stored properly, the majority of current season extra virgin olive oils will retain good flavor, aroma and freshness for at least 12 months.
 
Should I only buy 'first cold pressed' oil?
The question is not particularly relevant in light of the way extra virgin olive oil is made today. The vast majority of extra virgin olive oil produced throughout the world is done so without using a traditional olive oil press. Nearly all extra virgin olive oil is made using high speed centrifuges which spin the lighter olive oil away from the other heavier components of the olive such as water and pulp. As such, the term as it was first coined has little relevance today.
 
What do I look for in a retailer of extra virgin olive oil?
A good retailer knows the oils he or she stocks, where it comes from, when it was made and how it was stored. Good merchants should be able to advise you on the right style of extra virgin olive oil for your intended use, allow you to try the oil before purchase, have a high turnover, and only stock the fresh oils from the most recent olive crop.
 
Where is the best place to store the extra virgin olive oil?
Both light and heat are the enemies of olive oil. As such, olive oils should be stored in a cool place, out of direct light. A cupboard or pantry works well. On the countertop can work also, provided it is away from a window and not next to the stovetop. Olive oils will rapidly become rancid if stored in a warm, well lit environment. Exposure to light also hastens the loss of the antioxidant benefits of the oil.
 
What is the difference between extra virgin olive and those labeled “pure” or “light?”

Extra virgin olive oil is essentially the naturally extracted juice from fresh olives. The olives are crushed into a paste, and the oil is physically extracted from this paste without the use of chemicals or excessive heat. Extra virgin olive oil has a distinctive olive fruity aroma and flavor and it contains natural antioxidants.

'Pure' and 'light' are olive oils that have been refined. Refining is a complex process that involves the use of acids, alkalis, steam and other agents. The refining process removes all of the aroma and flavor substances out of olive including its natural antioxidants. Artificial antioxidants such as butylated hydroxyanisole (BHA) and the related compound butylated hydroxytoluene (BHT) need to be added back to give the refined olive oil a reasonable shelf life.

As such, unlike extra virgin olive oil, “Pure‟ and “Lite‟ olive oil lack the aroma, flavor and any pepperyness. In fact the word “light‟ only refers to the light color, and has nothing to do with reduced calories.
 
Does the color of the olive oil say anything about its quality?

Not quality, but it can tell you other things. The color of an olive oil is related to the amount of chlorophyll it contains. Olives are picked early in the season tend to make green colored oil as they contain higher levels of chlorophyll. Olives harvested late in the season will typically produce more golden colored oils due to a higher level of natural occurring levels of carotene like substances. Both oils may be technically equivalent in quality but very different in style. There are also many examples of green colored oils that taste remarkably ripe, and golden oils that have strong grassy herbal characters. To make matters more complex, many strongly green colored oils will turn a more golden color when stored.

Don’t place too much emphasis on color. Incidentally if you purchase very green looking oil make sure that it always stored in a dark bottle away from direct light. The stuff that makes it green (chlorophyll) helps start the reaction that makes oils rancid, but only in the presence of light.