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| AUGUST 13, 2002 MOVEABLE FEAST By Thane Peterson
It's the sort of question that pops into your head when the sun is beating down on you. Fortunately, you don't need to take your spatula to the street to get the answer. You can plop into a lounge chair, arm yourself with a cold drink, and read Robert L. Wolke's latest book, What Einstein Told His Cook (W.W. Norton, $25.95). Wolke, an emeritus professor of chemistry at the University of Pittsburgh, is one of the great demystifiers of scientific information. But if you're into food -- or just want to win more arguments with someone who is -- this is the book to read. EGGSTREME TEMPERATURES. This is the third book in Wolke's "What Einstein..." series, the others being What Einstein Didn't Know: Scientific Answers to Everyday Questions and What Einstein Told His Barber: More Scientific Answers to Everyday Questions. This latest one comes out of "Food 101," a column he writes every other week for The Washington Post. The book is perfect vacation reading because you can dip in at just about any point and come out with some interesting tidbit. Wolke is wonderful at answering those vexing food questions you always wondered about but never got around to investigating yourself. To investigate the egg assertion, he actually went out and measured the pavement temperature in Austin, Tex., during a heatwave. He found that the hottest it got, even on blacktop, was 145 degrees F -- well below the 158 degree minimum needed for an egg to start coagulating. Not satisfied with pure theory, he cracked an egg on the pavement and waited. Nothing happened. Helpfully, Wolke then went around measuring the temperature of other surfaces, and reports that a dark blue Ford Taurus reached 178 degrees F, making it a better frying pan than sidewalks or roadways."The wonderful thing about science is that it can even explain things nobody needs to know," Wolke concludes. WAVY GRAVY. Many of Wolke's other topics are similarly whimsical. He discovers that heavy cream is lighter than light cream because it contains more butter fat, which weighs less than water. And crackers have holes in them because it's impossible not to get some air mixed into the batter when cooking in batches, so those little holes are there to prevent scorching and unsightly bulges. Triscuits may appear to be solid but they actually each have 42 tiny holes in them, according to Wolke. (I can report, after an investigatory trip to my cupboard, that each Ritz cracker has seven holes in it.) There's also some genuinely useful information in the book. Tired of lumpy gravy? After a four-page discussion of the science behind gravy lumps, Wolke provides a surefire recipe for lumpless chicken or turkey gravy (you'll find it on pg. 155). And if you've been avoiding cooking in aluminum pans for fear of contracting Alzheimer's disease, you can stop worrying. One study two decades ago did find elevated levels of the metal in the brains of Alzheimer victims. But much subsequent research has failed to establish a link between aluminum cookware and the disease. The Alzheimer's Assn., the FDA, and Health Canada all say there's no reason to avoid aluminum. Wolke passes on a number of money-saving tips, too. Cheap hardware store paint brushes "are virtually identical" to expensive pastry brushes, he reports. And if you've been using expensive sea salt or other designer salts in your cooking, don't bother, he advises. Salt is salt and it comes to exactly the same thing when mixed in food. Wolke thinks it's nut to pay $5 per pound for "popcorn salt." Plain old Morton's, at a fraction of the price, is the same thing, chemically speaking. SALT SENSE. Typically, though, Wolke also taste-tests designer salt and reports that expensive French fleur de sel -- preferred by chefs and other connoisseurs -- has a "fragile, pyramidal crystal shape" that "does indeed produce a delightfully crunchy salt-burst when sprinkled on relatively dry foods before serving or at table." He also says there's a lot of misinformation in cookbooks. Most people put salt in the water for cooking pasta and potatoes. But does it really matter (as many cookbooks claim) when you add the salt, before or after boiling? Adding salt to the water shortens the cooking time by all of half a second, Wolke calculates. The real reason for adding it is simple: Salt brings out the flavor in food, which is why we sprinkle it on so many foods in the first place. Science, of course, can't solve every controversy. The weighty issue of whether barbecuing is best done on a gas grill or over coals is a good example. Wolke comes down on the side of charcoal, but for no better reason than that's what he prefers. LONG THAW. And over the weekend, I had bad luck with his sure-fire method for defrosting frozen food by simply placing it in an unheated heavy frying pan. Wolke says the metal of the pan is an efficient conductor and will quickly draw in the ambient heat of the room to thaw the food. I waited a while, but figure I would have been eating Saturday's spaghetti sauce at noon Sunday if I had continued following his advice. My spaghetti sauce aside, the book is a lot of fun and with its anecdotal style and wealth of information makes for great summer reading. And just think of all the bar bets you'll win. Peterson is a contributing editor at BusinessWeek Online. Follow his weekly Moveable Feast column, only on BusinessWeek Online Edited by Patricia O'Connell |
