WASHINGTON • I went looking for extra tomatoes at the farmers market this weekend (my backyard crop is not up to par this year), and I got another “extra” as well: a brief refresher course about extra-virgin olive oil.Thanks to my farmers market tutor, Keith Voight, I can now pass this true-false quiz. Can you? (Answers below.)1. The designation “extra-virgin” means something different in the United States than it does in Italy, Spain, France or Israel.2. A real extra-virgin olive oil has no defects in taste or odor and a very low level of acidity.3. Olives pressed for extra-virgin oil can be picked early or late in the fall-to-winter season.Voight owns All Things Olive, an online retailer based in Kensington, Md. He has sold exclusively Californian extra-virgin olive oils for five years. He also spends a fair amount of time educating others about the oil’s particular characteristics.At its essence, real extra-virgin olive oil is pure, raw, unprocessed and unrefined, with no defects in taste or odor and with less acidity (oleic acid) than virgin or pure olive oils. And it has to be extracted from the olives within a day of when they are picked, to keep that acidity low.He carries extra-virgin olive oils that are mild and delicate; fragrant and fruity; leafy and grassy; olive-y and peppery. Their flavor depends in part on at what point the olives were picked during their October-January harvest.It’s his contention that most Americans have never really tasted extra-virgin olive oil because of its relatively low yield and the extra care it takes to produce it properly. His line is all-Californian because the state has its own olive oil control board (look for state-made oils with a COOC seal) and takes its olive oil production seriously, with a study center at UC-Davis and various organizations aimed at standardizing and improving quality.Voight does not think Californian extra-virgin olive oils are on a par with some of Europe’s finest — not yet, anyway. But he does prefer them to imported oils because freshness is key, and that advantage goes to the extra-virgin olive oils made and sold in the Golden State.A tasting of his selections led me to choose the mild, late-harvest Apollo Mistral, made in northeast California. It is soft and buttery, good for white wine dishes, salads and seafood, he says. Last night I drizzled it into orzo with medallions of lobster, sautéed corn, scallions and tomatoes. Because it’s in a dark bottle and only 375 ml, it will remain unaffected by sunlight (which can break it down) and I’ll most likely use it up fairly quickly.If I wish to use it instead of butter in recipes, I’ll try this handy dandy chart I found at OliveOilSource.com:

BUTTER = OLIVE OIL1 teaspoon = 3/4 teaspoon1 tablespoon = 2-1/4 teaspoons1/4 cup = 3 tablespoons1/3 cup = 1/4 cup1/2 cup = 1/4 cup + 2 tablespoons2/3 cup = 1/4 cup3/4 cup = 1/4 cup + 1 tablespoon1 cup = 3/4 cup

QUIZ ANSWERS1. True.Italy, Spain, France and Israel (and some other countries) have their own olive oil control authorities; real extra-virgin olive oil from those nations should carry a seal on the bottle. In the United States, the USDA grades olive oils as “fancy,” “choice” or “standard,” with fancy serving as the equivalent of extra-virgin. Many oils produced in the States call themselves extra-virgin, but that may not be the case.2. True.To be classified as extra-virgin, an olive oil must have no taste or odor defects (according to the International Olive Oil Tasting Council based in Madrid), and it must be free of oleic acid (below 0.8 percent), which is a measure of how ripe the fruit was when pressed.3. True.Olives picked early are green and can be used to produce extra-virgin olive oils with a bitter edge. Olives picked late are more ripe and black, and can become extra-virgin olive oil with a flavor toward the milder end of the spectrum.

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