A good olive oil is a real treat, whether you're dipping a piece of crusty bread into it....adding it to a bean salad ... or drizzling it onto a tomato, mozzarella, and basil appetizer.

Consumer Reports just tested 23 extra-virgin olive oils from countries including Italy and Spain, as well as the state of California.

Expert consultants assess freshness and olive fruit flavors and determine if there are any defects, like oxidation.

Erin Gudeau with Consumer Reports says, "As the oil ages, it goes from slightly stale, wet cardboard, papier-mâché flavors all the way to rancid, painty notes."

Extra-virgin olive oils are supposed to be top quality.

Erin explains, "It not only has to pass some basic lab tests, but on top of that it has to have an absolutely defect-free flavor, no off-notes at all."

But testers found only nine of the 23 oils truly tasted like extra-virgin olive oil.

And several big name oils, including ones labeled extra-virgin from Bertolli and Goya, rated only fair.

But Consumer Reports did find two excellent olive oils. Both are from California.

The McEvoy Ranch olive oil has an intense aroma with a distinct, balanced olive fruit flavor. But it's pricey at $22 a bottle.

Far less - Trader Joe's California Estate olive oil at $6 dollars a bottle. It has very complex and balanced flavors, with a strong aroma.

Either would be a welcome addition to any dish that calls for drizzled olive oil.

Two other less-expensive olive oils rated very good in Consumer Reports' tests. They're the Kirkland Signature Select Toscano from Costco and Whole Foods' 365 Everyday Value 100% California Unfiltered Olive Oil.

Be aware, when it comes to cooking, there's no need to use a pricey olive oil. That's because high heat can destroy the subtle flavors.