The rest of the world will have to forgive Americans if we seem slightly schizophrenic about our food and drink. In recent years, we have been bombarded with so much information and advice about our eating habits that we have become a nation of two minds: We have turned Eric Schlosser into a 21st-century Upton Sinclair by gobbling up his expose Fast Food Nation, but we frequented McDonald’s to the tune of $20 billion last year (a 2 percent increase over the number of burgers, fries, and Chicken McNuggets purchased in 2000, for those keeping score).

We buy thousands of cookbooks annually that promote low-fat, healthy foods, and yet the No. 3 best-selling book in Amazon.com’s “Cooking, Food, and Wine” section (as of June 26) is Weber’s Big Book of Grilling. We appear to live in fear of the almighty saturated fat, but we’re considered denizens of the most corpulent country in the world—a fact that caused the U.S. surgeon general to issue a “call to action” in December 2000 because an estimated 300,000 Americans are dying annually from obesity-related causes. We don’t know whether we should chug a beer daily to lower our risk of cardiovascular disease or become teetotalers to prevent our livers from misbehaving in old age. And let’s not even get into the highly charged issue of meat eaters vs. animal-loving vegetarians (or, God forbid, vegans).

Stepping calmly into the morass is Robert L. Wolke, professor emeritus of chemistry at the University of Pittsburgh and author of the folksy, informational Food 101 column in the Washington Post. With the third installment of his Einstein series, What Einstein Told His Cook: Kitchen Science Explained, Wolke doesn’t exactly tell us what foods we should eat. He does something better: He explains many of the foods we eat. And I, for one, find comfort in his explanations; call it the power of science to calm those vague, free-floating anxieties generated from generally underresearched diatribes directed at the foods we eat.

Take, for example, Wolke’s dissection of refined white sugar, that demon sweetener. He takes readers on a concise trip through the process of refining raw sugar-cane juice—essentially, it boils down to repeatedly boiling down the liquid, allowing it to evaporate into wet crystals, and then spinning the crystals until the molasses is removed—and then poses a somewhat mocking question to overzealous health nuts:

My point is this: In raw cane juice you have a mixture of sucrose plus all the other components of cane that end up in the molasses. When the molasses components are removed, will someone please explain to me how the remaining pure sucrose suddenly becomes evil and unhealthful? When we eat the more “healthful,” browner sugars, we’re eating just as much sucrose along with the molasses residues. Why isn’t the sucrose evil in that form?

Wolke proves to be a calming influence in other controversial areas, too. Name your poison: MSG (monosodium glutamate may just be a scapegoat; the villain in question, free glutamate, can be found in other foods—such as mushrooms, tomatoes, and Parmesan cheese), green-rimmed potato chips (the color is caused by the toxic chemical solanine, which can cause ill effects only if you “eat so many bags of chips that you’d turn greener around the gills than they are around the frills”), and coffee acids (“the acid in our stomachs…is thousands of times stronger than any acid you’ll find in coffee”).

The chemist even tackles a question that would be laughed right out of most food-related chat rooms: Does belching contribute to global warming? It’s a legitimate question, Wolke argues: Americans consumed 15.2 billion gallons of carbonated soft drinks and 6.2 million gallons of beer in 1999. That adds up to 800,000 tons of carbon dioxide, one of the so-called greenhouse gases that lead to global warming. “And what do you suppose happened to all the carbon dioxide in those beverages?” he asks. The answer, as Wolke likes to say, will surprise you.

Wolke may be a chemist with a preternatural ability to explain complex chemical reactions in simple terms, but he’s also something of a philosopher. The penultimate topic in What Einstein Told His Cook is food irradiation, the process of exposing foods to intense gamma rays, X-rays, and the like to kill potentially lethal bacteria. He neatly sidesteps the socioeconomic questions surrounding irradiation but then lets loose a flow of corrosive words toward those consumers obsessed with “food safety.” He makes his pointed points not just with science but also with a statement of belief that borders on fatalism:

Is food irradiation safe? Are airplanes safe? Are flu shots safe? Is margarine safe? Is living safe? (Of course not; it invariably ends in death.) I don’t mean to belittle the question, but “safe” is probably the most useless word in the English language. It is so loaded with contexts, connotations, interpretations, and implications that it loses all meaning. And, of course, a meaningless word belies the very purpose of language.

If this is a statement of belief, it’s also something of a mission statement. Wolke approaches his task with little care for his own professional safety; his breadth of topics reflects the choices of a man who doesn’t care what you think of their importance (or has to crank out a column with alarming regularity). As a result, his book covers the ridiculous (“Can you really fry an egg on the sidewalk?” “I’m confused by all the separate compartments in my refrigerator. What am I supposed to keep in each?”) alongside the sublime (“How do microwaves make heat?” “What are all those salt substitutes that I see in the market? Are they safer than real salt?”).

But whatever the magnitude of the topic, Wolke addresses it with the same understated intelligence and paternal humor. It’s like having an eccentric uncle to dinner: Wolke wants to share his accumulated wisdom, but he wants to season it with bad puns and jokes ripe enough to make you hold your nose. He manages to pull off an amazing bit of intellectual manipulation: He downplays his scientific credentials with geeky self-effacement when, in fact, his scientific credentials are the very reason you pick up the book in the first place. Yes, it can be quite charming, especially when he can occasionally rise to one-liners such as “When sunlight hits Earth’s surface, about two-thirds of it is absorbed by the clouds, the land, the sea, and George Hamilton.”

Wolke’s clownish high-wire act goes only so far, though. He seems to high-tail it toward safe ground whenever he nears a shaky business practice. Not only does he refuse to take a public stand on potentially questionable applications of food irradiation (could large companies recklessly use it to cover up poor farming practices?), but he makes at least two statements that I perceive as misleading. In the chapter titled “Turf and Surf,” Wolke explains why some animal meat is white and some dark (it has to do with the amount of myoglobin in the muscle tissue). The author rightly acknowledges America’s love for white chicken meat and how it translates into farming methods. Says Wolke: “In fact, unless they are given free range, today’s American-bred chickens are so pampered that even their ‘dark meat’ is as white as their breasts.”

Pampered? Huh? I’m sure Wolke has heard of factory farms, where these “pampered” chickens don’t exert much energy because they can’t. They’re often crowded in spaces no larger than a square foot per bird. Animal-welfare activists make a living fighting these practices.

His second misleading statement appears in the same chapter, where Wolke discusses the USDA Prime label, which is reserved for only the choicest (and most expensive) cuts of beef. Again, he rightly acknowledges that some restaurants advertise “prime rib,” only to serve a piece of meat “with vulcanized-rubber fat that clearly deserved to be stamped ‘USDA Inedible.’” But then he asks: “Is there some misrepresentation going on here?” To which he answers, “Not necessarily.” To which a majority of food critics would groan in unison.

OK, so Wolke plays nice with business. So be it. What he appears to lack in social activism, he more than compensates for in the kitchen, where he and his wife, Marlene Parrish, have developed or tested a number of fascinating recipes to complement some of Wolke’s scientific topics. There are a number of intriguing recipes here, including a nondairy chocolate mousse that uses olive oil. “The chocolate flavor is intense,” Wolke writes, “but in spite of the generous amount of extra-virgin olive oil, its flavor is subtle.”

I would have loved to test this recipe, and others, but when I asked my editor whether I could expense the ingredients for any dish I prepared, she said, “Only if the food’s inedible.” It would seem that, on occasion, we all have to defer to the harsh realities of business. CP