Any cooking in the 400 F plus range requires an oil with a high smoke point, but which one? I've done some reading and changed my dirty, chemically refined, peanut oil ways. You will now find me in the organic aisle, picking through the tasty range of USDA Certified Organic Oils labeled "Medium to High Heat" or "Very Hight Heat." Each one has a cute little graphic on the back of the bottle showing a gauge with the needle pointed in the red range.
Why the fuss? The problem with non-organic oils isn't so much how the plants were grown, important as that is. What matters is how the oil is extracted and then refined to render it suitable for high temperature cooking. Whether it's canola, safflower, sunflower, avocado, almond or apricot - all oils with extremely high smoke points, by the way- all that chemical extraction and the processes used to essentially bleach the oil are pretty nasty. Hexane, one of the more charming chemicals Julia Roberts battled as Erin Brockovitch in the film of the same name, is one of the chemicals used to refine commerical high-heat oils. Worse - or just as bad, anyway - when oil gets really hot the compounds in it breakdown, presumably including the chemical residue used to extract and refine it, releasing free radicals into the oil and into the air. Breathing and eating these degraded chemicals is not good for you. Obviously I'm not a scientist but the facts on this issue seem pretty clear: Look for that goofy but helpful little gauge on the back of the bottle and stick to USDA Certified Organic oil.
*Sorry, grapesdeed oil, the go-to oil of many chefs, just doens't have all that high a smoke point.