Excerpted from Secrets of the Southern Table, by Virginia Willis:

All oil has what's called a smoke point, which is just what it sounds like: the point at which oil starts smoking and breaking dovm when heated. Canola oil is flavorless and has a high smoke point, so I use it a lot in recipes where I want the flavor of the food to shine through and when I need to cook at a high temperature. Olive oil has a lower smoke point and imparts its own flavor, so I use it on lower-temperature recipes where I want the flavor of the oil to add to the flavor of the dish. When choosing an olive oil for a rec­ipe, I often look at the country in which the oil was produced; generally speaking, the hotter the country where the olives were grown. the more robust the flavor of the oil. (For exan1ple. olive oil from Italy tastes dif- ferent from olive oil produced in Greece.) Of olive oils, extra virgin is the highest­quality oil, and you'll note many recipes in this book specifically call for it. Extra virgin is cold pressed, using pressure only, without heat or chemicals. It's fairly unrefined and has a moderately low smoke point; it is best used for dipping. drizzling, and dressings. Pure olive oil is more refined, has a higher smoke point, and is better for cooking.