Can olive oil be substituted in every recipe that calls for vegetable oil?
–Frank in St. Louis
Almost. In the “authentic” camp, purists believe olive oil doesn’t belong in cuisines where olives never existed. In your kitchen, it’s your call.
You can replace neutral-tasting vegetable oils with subtle, reasonably-priced extra virgins like Carapelli and Monini. For bigger olive flavor and reasonable cost (in extra virgin olive oil, “reasonable” is between maybe $10 and $16 a quart), look at Costco’s Kirkland Toscano, Morea, Spectrum’s olive oils and Whole Foods 365.
As far as health goes, you want extra virgin oil, which is processed with neither heat nor solvents so all the oil’s nutrients stay intact. Light olive oils are to the olive what Styrofoam is to bread -- lifeless and characterless, yet with all the calories of every other oil.
By the way, food scientist Harold McGee, author of On Food and Cooking, wrote a very interesting piece about cooking with olive oils for The New York Times awhile ago. Take a look if you get a moment, it may save you some money.