With good reason. Olive oils are a lot like wines. The olives that produce them, like the grapes that go into wine, come in many varieties and reflect qualities determined by the land, sun and water where they grow. And like wines, olive oils sell at vastly varied prices. And again, like wines, there are some you wouldn't want to taste on their own that are perfectly OK for cooking.

With the focus on olive oil as a healthful fat, the increasing availability of a wide variety of oils, and the new opportunities to taste them at stores and markets, it's time to learn a little bit more about how to make a good choice.

First, the virgin thing.

• Extra-virgin olive oil is the first, cold pressing of the olives, with acid of 1 percent or less.
• Virgin olive oil is first press with a slightly higher acid content — up to 3 percent.
• Plain olive oil (formerly "pure" olive oil) is a blend of extra-virgin and refined olive oil, with the highest acid content and generally the least flavor.
• Light olive oil has been additionally filtered; it has the same fat and calories but is lighter in color and fragrance.

Each of these types of olive oil has its uses:

• Cooking (for sautéing and frying).
• Ingredient (for salad dressings and marinades).
• Dipping (oils so tasty you can use them instead of butter with bread).
• Finishing or drizzling (to glaze or add a layer of flavor to roasted meats, grilled fish, prosciutto or carpaccio, cold foods, and vegetables such as fresh tomatoes).

Olive oils may be filtered, to remove particulates, or unfiltered and cloudy with solids, even at room temperature.

And olive oils range from bright emerald to a surprising chartreuse. Bright color can be indicative of stronger flavor.

Got that?

So which are best for what?

• Use only light or plain olive oil for frying — these types have a higher smoke point. You may also sauté with light or plain olive oil.
• Filtered virgin or extra-virgin may be used for sautéing, but don't waste money on the most flavorful or expensive brands for this. These are also best for ingredient use, because you're going to pile on the herbs, aromatics and other flavorings anyway.
• The more carefully made, highly colored, flavorful and expensive extra-virgin olive oils should be reserved for dipping, finishing and drizzling.

Here in Hawai'i, we've got one big problem with olive oils — as with many other foods. The best place to keep olive oils is a cool, dark, dry place. Olive oils, especially unfiltered ones, degrade rapidly in the presence of light and heat.

Olive oil labels contain quite a bit of information, but not necessarily one of the most important things — the age of the oil. The government does not require that packages tell you when the oil was pressed or bottled. Those that do include that information tend to be boutique brands.

In olive oils, youth is a good thing. Oils will stay reasonably fresh for 12 months after bottling and be fine for another year — if kept in that mythical cool, dark, dry place. But after that, the flavor diminishes. So do the aroma and some of the health benefits. That's why — when you are buying high-quality oils — it makes sense to look for those that are harvest-dated.

One way to prolong the life of a fresh oil is to keep it away from light. Look for makers that package their oils in dark glass bottles or opaque ceramic jars. Or store the jar inside a paper bag.

Color and aroma are good indicators of age. Younger oils tend to have more intense colors, as well as fresher flavors and aromas.

None of this goes to the issue of flavor. Equally well-made oils may have radically different flavors. The only way to make a good choice is to taste the oil first. Unfortunately, here in Hawai'i few retailers routinely offer tasting bars in the way that such stores as Trader Joe's and Whole Foods do on the Mainland. R. Field at Foodland does keep some oils under the counter for tasting and will do a comparative tasting from time to time.

When you do get a taste, you'll notice that some oils are light and fruity while others are peppery and assertive. In general, the lighter oils go well with salads and cold foods while the more pungent oils are nice for finishing off grilled meats or stews, or stirring into mashed potatoes.

With many full-flavored oils, the taste and aroma point to the birthplace, the olive groves from which the oil was made. Good French oils, for example, tend to be more flowery.

If you want to try a comparative tasting of your own, get some friends together and ask everyone to buy a different oil.

Pour a little oil into a small glass. Warm the glass with your hands. Check out the aroma. Look at the color. Savor the taste on your tongue, and as it goes down your throat. Dip a piece of bread or a sliced vegetable in it, too. You just might find you know more about olive oil than you realized.