Perhaps this helps explain the keen pleasure we seem to take in all kinds of aerated foods and beverages: the sparkling wines and sodas, the souffles and whipped cream, the lofted breads and ethereal croissants and weightless meringues, and the laminated pastries with their 128 layers of air. Bakers and chefs labor mightily to work sweet nothings into their creations, striving to deliver the most flavorful airs deep into our mouths. The palate of taste is limited to the five or six primary colors that the tongue can recognize; olfaction, by comparison, is seemingly limitless in the shadings and combinations it can register and archive-and retronasal olfaction can perceive aromas to which even the nose is blind.

Symbolically, too, air is not nothing. Air elevates our food, in every sense, raises it from the earthbound subsistence of gruel to something so fundamentally transformed as to hint at human and even divine transcendence. Air lifts food up out of the mud and so lifts us, dignifying both the food and its eaters. Surely it is no accident that Christ turned to bread to demonstrate his divinity; bread is partially inspired already, an everyday proof of the possibility of transcendence.*

What other food could do all this symbolic work and yet still reliably fill human bellies? No wonder long stretches of European history can be told as the story of bread, or, rather, its two stories: a fight for access to bread on the part of Europe's peasantry and working cla.s.s, and a fight over the meaning of bread on the part of its elite. For what was the Reformation if not an extended, centuries-long argument over the proper interpretation of bread? Was it merely the symbol of Christ or his actual body?

Around the time I felt like I could reliably bake a voluminous white loaf, I hatched the idea of preparing an entire dinner on the theme of air, and one Sat.u.r.day Samin and I got together at my house to cook it. In addition to a couple of nicely lofted loaves of Tartinian bread that I'd baked, we made two souffles, a savory green-garlic one to serve with dinner, and a rose-and-ginger one for dessert. For the main course we served (what else?) a bird, albeit a flightless one: chicken. I broke out a bottle of vintage champagne. And Samin made honeycomb candy, a hard yet weirdly effervescent brittle made by stirring a spoonful of baking soda into a bubbling pot of caramelizing sugar.

The evening was a spree of retronasal olfaction, but what made the most lasting impression was the ginger-and-rose souffle. There was actually not a speck of ginger or rose in it, just a few drops of essential oil, one distilled from ginger root and the other from the petals of roses. The recipe came from an eccentric cookbook t.i.tled, simply, Aroma, the collaboration of a chef, Daniel Patterson, and a perfumer, Mandy Aftel. It called for a tremendous number of egg whites whipped to an airy froth. The alb.u.men proteins in the whites of eggs can hold air much like gluten does, allowing the cells of gas whipped into it to expand dramatically when heated. For the base, instead of calling for an equivalent number of yolks to carry the flavor, or cream, the recipe called for yogurt, which made for a souffle (the word of course means "blown") even more dematerialized than usual. Its flavor was powerful yet largely illusory, the result of the way the essential oils played on the human brain's difficulty in distinguishing between information obtained by the sense of taste and that provided by the sense of smell. Each weightless bite amounted to a little poem of synesthesia-a confusion of the senses that delighted. It made for a fitting end to an effervescent evening.

By now you will not be surprised to learn that Gaston Bachelard had a few things to say about the element of air. In a book called Air and Dreams, he points out that we categorize many of our emotions by their relative weight; they make us feel heavier or lighter. Perhaps because uprightness is the human quality, we imagine human emotions arranged on a vertical scale from ground to sky. So sadness is weighed down and earthbound, joy is aerial, and the sensation of freedom defies the bonds of gravity. "Air," Bachelard writes, "is the very substance of our freedom, the substance of superhuman joy."

Elation, effervescence, elevation, levity, inspiration: air words all, alveolated with vowels, leavening the dough of everyday life.

II.

Thinking Like a Seed

Not that I want to puncture my own balloon now that it is finally aloft, but I'm afraid I have no choice. As mentioned, the loaf that I mastered, or nearly so, is a loaf of white bread, and white bread is ... well, problematic. I came to see that I had been bewitched by the aesthetics of bread, completely losing sight of certain other desirable qualities in a food, such as nutrition. (Oh, that!) Eating white bread is a little better than eating pure starch, which is itself a little better than eating pure sugar, but not by much. I have been dwelling here on the wonders of gluten, but of course those proteins represent only a fraction of the calories in white flour-at most maybe 15 percent. The rest, I'm afraid, is starch, which, beginning on the tongue, our enzymes swiftly translate into glucose-sugar. Americans obtain a fifth of their calories from wheat-and 95 percent of that is in the form of nutritionally nearly worthless white flour. I say "nearly" because, ever since the nutritional vacuousness of white flour became impossible to ignore, early in the twentieth century, governments have required that millers add back in a handful of the nutrients (B vitamins, mainly) that they have gone to such great lengths to take out.

Stand back far enough, and the absurdity of this enterprise makes you wonder about the sanity of our species. But consider: When millers mill wheat, they scrupulously sheer off the most nutritious parts of the seed-the coat of bran and the embryo, or germ, that it protects-and sell that off, retaining the least nourishing part to feed us. In effect, they're throwing away the best 25 percent of the seed: The vitamins and antioxidants, most of the minerals, and the healthy oils all go to factory farms to feed animals, or to the pharmaceutical industry, which recovers some of the vitamins from the germ and then sells them back to us-to help remedy nutritional deficiencies created at least in part by white flour. A terrific business model, perhaps, but terrible biology.

Surely this qualifies as maladaptive behavior on our part, and yet humankind has been intent on whitening wheat flour almost as long as we have been eating bread. But we didn't get really good at it till the nineteenth century, with the advent of roller mills that could cleanly scalp all the germ and bran from the seed, and the subsequent discovery that, by exposing milled flour to gusts of chlorine gas, we could whiten it still further by expunging the last remaining nutrient from it: the beta-carotene that tinted flour just slightly yellow. What a triumph!

Before these dubious achievements, the best millers could do to whiten flour was to sift, or "bolt," wheat that had first been crushed on a stone wheel. But the millstone usually smushed the germ into the endosperm, so people couldn't avoid eating those nutrients, and bolting could only catch and remove the biggest, chunkiest bits of the bran, leaving behind a fair amount of fiber. The result was an off-white flour that was nourishing enough to keep alive all those people for whom wheat made up the bulk of their diet-which until the last century or so was most of the population of Europe. Though it looks white, the bread "with the old soul" in the painting by emile Friant that inspired Chad Robertson was almost certainly made with this kind of flour.

The quest for an ever-whiter shade of bread, which goes all the way back to the Greeks and Romans, is a parable about the folly of human ingenuity-about how our species can sometimes be too smart for its own good. After figuring out an ingenious system for transforming an all but nutritionally worthless gra.s.s into a wholesome food, humanity pushed on intrepidly until it had figured out a way to make that food all but nutritionally worthless yet again!

Here in miniature, I realized, is the whole checkered history of "food processing." Our species' discovery and development of cooking (in the broadest sense of the word) gave us a handful of ingenious technologies for rendering plants and animals more nutritious and unlocking calories unavailable to other creatures. But there eventually came a moment when, propelled by the logic of human desire and technological progress, we began to overprocess certain foods in such a way as to actually render them detrimental to our health and well-being. What had been a highly adaptive set of techniques that contributed substantially to our success as a species turned into a maladaptive one-contributing to disease and general ill health and now actually threatening to shorten human lives. When and where did we pa.s.s over, from processing food to make it healthier to making it less so? To what might be thought of as "overcooking"? There are a couple of places we could reasonably draw that line. The refining of pure sugar from cane or beets would certainly be one. But perhaps the sharpest and clearest line would be the advent of pure white flour (and the bread made from it) in the second half of the nineteenth century.

The prestige of white flour is ancient and has several sources, some practical, others sentimental. Whiteness has always symbolized cleanness, and especially at times when disease has been rife and food frequently contaminated, the whiteness of flour symbolized its purity. I say "symbolized" because for most of history it was no guarantee: Unscrupulous millers routinely whitened their flour by adulterating it with everything from alum and chalk to pulverized bone. (For centuries both millers and bakers have been regarded with suspicion, often with good reason. It has always been hard to determine what exactly is in a bag of flour or a loaf of bread, and easy to pa.s.s off ingredients that are cheaper and less wholesome than wheat flour. This is why, during periods of hunger and political ferment, millers and bakers were frequent targets of popular wrath, occasionally put in the stocks and pelted with bad bread.)

Adulterated or not, however, white (or whitish) flour was generally regarded as healthier than whole grain well into the nineteenth century. "Coa.r.s.e flour"-wheat that had simply been ground on a stone and never sifted-was coa.r.s.e indeed, and gradually ground down the teeth of the people who had no choice but to eat the dark bread made from it. Sifted flour was also thought to be easier and swifter to digest, and certainly for people struggling to obtain enough calories, white bread was a superior source of quick energy. It was also easier to chew, no small thing before modern dentistry.

So the rich demanded the whitest possible flour, and the poor were left to eat "kaka," as the French sometimes called brown bread. Going back to ancient Rome, the shade of the bread you could afford precisely indicated your social standing; to know one's place, Juvenal wrote, is "to know the color of one's bread." Some historians and anthropologists have suggested that the prestige of white flour might also have had a racist tint to it. Maybe. And yet white rice has enjoyed a similar prestige in Asia, among nonwhites, so maybe not.

Whitish flour, which before roller mills could only be obtained by sifting flour through progressively finer meshes of cloth, had a lot to recommend it. Bran tends to be bitter, so the whiter the flour the sweeter the bread. White flour also made for a much airier loaf; even the microscopic shards of milled bran are sharp, and, like millions of tiny knives, they can pierce the strands of gluten in dough, impairing its ability to hold air and rise. (On the same principle, some gardeners kill slugs by spreading wheat bran in their path.) Those tiny bran knives are relatively heavy, too, making it more difficult to leaven a whole-grain loaf. Even at its best, it will never achieve the exaltation of a loaf made with white flour.

As a solution to these problems, sifting coa.r.s.e flour was less than ideal. The multistep process was time consuming and expensive. It also failed to address what is perhaps the most serious rap against whole-grain flours: their relatively short shelf life. Whole-grain flour tends to go "off" within several weeks of being milled, releasing an unmistakable odor of rancidity. Part of what makes the germ so nutritious-its unsaturated omega-3 fats-also makes it unstable, and p.r.o.ne to oxidization. Sifting might whiten stone-ground flour, but it could not remove the perishable germ, which meant that flour had to be milled frequently and locally. This is why every town used to have its own mill.

The advent of roller milling in the middle of the nineteenth century made white flour cheap, stable, and whiter than it had ever been. For a revolutionary technology, roller milling seems almost obvious, and benign. The new mills replaced the old millstones with a sequence of steel or porcelain drums arranged in pairs, each subsequent pair calibrated to have a narrower s.p.a.ce between them than the previous set, in order to grind the flour ever more finely. To begin, the seed is dropped between a pair of corrugated drums rotating in opposite directions. During the "first break," the bran and germ are sheared from the endosperm. Those parts are sifted out before the now naked endosperm moves on to the next pair of slightly more closely s.p.a.ced rollers, and so on, until the starch (or "farina") has been pulverized to the desired degree of fineness.

The new technology was greeted as a boon to humankind, and so at first it seemed. Bread became whiter and airier and cheaper than ever. Commercial yeast performed particularly well with the new flour, vastly speeding and simplifying the work of baking. The shelf life of flour, now that the unstable embryo had been eliminated, became indefinite, allowing the milling industry to consolidate. Thousands of local stone mills closed, since big industrial operations could now supply whole nations. Cheap, stable, transportable white flour made it possible to export flour around the world and to feed swelling urban populations during the industrial revolution. According to one history of bread,* the advantages of white bread were something on which both workers and employers could agree: Brown breads high in fiber "meant that workers had to leave their machines frequently to go to the lavatory, and this disrupted production."

Indeed, in many ways, white flour not only gratified human desires but also meshed especially well with the logic of industrial capitalism. No longer a living, perishable thing, flour now became a stable, predictable, and flexible commodity, making not only the production of bread faster and more efficient, but also its consumption. In effect, roller mills "sped up" wheat as a food, making it possible for the human body to absorb its energy much more readily than before. Flour, and bread in turn, became more like fuel and, at least calorically, more efficient. In the jargon of modern nutrition science, bread became more "energy dense," which, along with extended shelf life, is one of the most common outcomes of modern food processing. Not surprisingly, white flour proved enormously popular with a species hardwired by natural selection to favor sweet foods. The taste of sweetness, which signals a particularly rich source of energy, had always been rare and hard to find in nature (ripe fruit, honey), but with the industrial refining of certain cultivated gra.s.ses (wheat, cane, corn), it now became cheap and ubiquitous, with what would turn out to be unfortunate consequences for human health.

More than just a new food product, white flour helped usher in a new food system, one that would extend all the way from the field to the loaf of presliced and fortified white bread, which now could be manufactured on an a.s.sembly line in three or four hours without ever being touched by human hands. The wheat plant changed, too. The new roller mills worked best with hard-kerneled red wheat; the big, tough bran coat on this type of wheat could be sheared cleanly and completely from the endosperm, whereas softer white wheat left infinitesimal specks of bran in the flour. So, over time, breeding changed the plant to better suit the new machine. But because hard wheat has tougher, bitterer bran, it made whole-grain flour even coa.r.s.er and bitterer than it had been before-one of several ways that the triumph of white flour made whole wheat less good. Even today, breeders continue to select for ever-harder wheats with ever-whiter-and therefore less nutritious-endosperms. As Steve Jones, the former wheat breeder for the State of Washington, told me, "Wheat breeders are selecting against health."

Ah yes, health. Here was the fly in the ointment. The compelling industrial logic of white flour meshed beautifully with everything except human biology. Not long after roller mills became widespread in the 1880s, alarming rates of nutritional deficiency and chronic disease began cropping up in populations that relied on the new white flour. Around the turn of the century, a group of French and British doctors and medical experts began searching for the causes of what they dubbed "the Western diseases" (heart disease, stroke, diabetes, and several disorders of the digestive tract, including cancer), so called because they were virtually unheard of in places where people hadn't switched to modern diets containing large amounts of refined sugar and white flour. These medical men, many of them posted to Britain's colonies in Asia and Africa, had observed that, soon after white flour and sugar arrived in places where previously what one of them (Robert McCarrison) called "the unsophisticated foods of Nature" had been the norm, the Western diseases would predictably appear. Some of these doctors blamed the lack of fiber in the Western diet, others the surfeit of refined carbohydrates, and still others the lack of vitamins. But whatever the culprit nutrient or the precise mechanism by which it operated, these men were convinced of a link between processed white flour and sugar and the panoply of new chronic diseases. A large body of contemporary research suggests they were right.

What to do? Certainly not return to the "unsophisticated foods of Nature"-no one wanted to do that! And yet, by the end of the nineteenth century, several voices were raised in support of just such a course, including a return to whole-grain flour. "The true staff of life is wholemeal bread," declared Thomas Allinson, a prominent English physician, and one of the first to link refined carbohydrates to disease. To counter the scourge of white flour, in 1892 he bought a stone grinding mill and began baking and selling whole-grain bread under the slogan "health without medicine." (He was also involved in a group called the Bread and Food Reform League.) Earlier in the century, the American minister and nutritional reformer Sylvester Graham, eponym of the whole-grain cracker, had published an influential Treatise on Bread and Bread-Making that blamed white flour for many, if not quite all, of the ills of modern life, including constipation (a nineteenth-century scourge), and fervently extolled the virtues of coa.r.s.e dark breads high in fiber. To remove the precious health-giving fraction of bran from wheat was to "put asunder what G.o.d had joined together"-a fall from dietary grace for which modern man was paying with his troubled, sluggish digestion.

By the early decades of the twentieth century, public health authorities in England and the United States could no longer ignore the links between refined white flour and widespread nutritional deficiencies, including beriberi, as well as increases in the rates of both heart disease and diabetes. (It was noted that during both world wars, when the British government had mandated a higher fiber content in flour as part of food rationing, people's health improved and rates of type 2 diabetes declined.) But by now the White Flour Industrial Complex was so well entrenched that a shift back to whole-grain flour was never seriously contemplated.

Instead, the milling industry and government came up with a clever technological fix: A handful of the vitamins that modern milling had removed from bread would now be put back in. So in the early 1940s, in what was called "the quiet miracle," the U.S. government worked with baking companies-including the Continental Baking Company, makers of Wonder Bread-to develop and promote a white bread fortified with a handful of B vitamins. Here was a cla.s.sic capitalist "solution." Rather than go back to address a problem at its source-the processing of key nutrients out of wheat-the industry set about processing the product even more. This was sheer brilliance: The milling industry could now sell the problem and the solution in one neat package.

But fortifying white flour with the missing vitamins represents only a partial, reductionist solution to what turns out to be a much more complex problem. By now the nutritional superiority of whole grains over even fortified white flour is universally acknowledged-yet still only imperfectly understood. People who eat lots of whole-grain foods significantly reduce their risk of all chronic diseases; they also weigh less and live longer than people who don't. This much we know from the epidemiology.* But why, exactly? Is it, as Sylvester Graham believed, the benefits of dietary fiber? And if so, is it the fiber itself, or the various phytochemicals that typically accompany fiber? Or maybe it's the vitamins, not all of which are put back when flour is fortified. It could also be the minerals in the bran. Or the omega-3 fatty acids in the germ. Or it could be the antioxidants found in the "aleurone layer," the innermost layer of the bran. Scientists still can't say for sure.

But here is the most curious fact: People whose diets contain adequate amounts of all these good nutrients from sources other than whole grains (from supplements, say, or other foods) aren't nearly as healthy as people who simply eat lots of whole grains. According to a 2003 study by David Jacobs and Lyn Steffen,* epidemiologists at the University of Minnesota, the health benefits of whole grains cannot be completely explained in terms of the nutrients we know those grains contain: the dietary fiber, vitamin E, folic acid, phytic acid, iron, zinc, manganese, and magnesium. Either there are synergies at work among these nutrients, or there is some X-factor in whole grains that scientists have yet to identify. We are talking, after all, about a seed: a package that contains everything needed to create a new life. Such a recipe still exceeds science's powers of comprehension and technology's powers of creation.

The fact that a whole food might actually be more than the sum of its nutrient parts, such that those parts are probably best not "put asunder," poses a stiff challenge to food processors. They have always a.s.sumed they understood biology well enough to improve on the "unsophisticated foods of Nature," by taking them apart and then putting them back together again. The industry would be more than happy to sell us bread fortified with any one (or twelve or one hundred) of these nutrients if science could just tell it which ones to focus on. But, so far at least, science can't reduce this complexity to a simple answer.

This has been good news for the food itself: Whole-grain bread has been enjoying something of a renaissance. Actually, that renaissance got a first, false start during the 1960s, when the counterculture, steeped in romantic ideas about "natural food," seized on white bread as a symbol of all that was wrong with modern civilization. Brown bread, being less processed than white, was clearly what nature intended us to eat. They probably should have stopped there, but did not, alas. Baking and eating brown bread also became a political act: a way to express one's solidarity with the world's brown peoples (seriously), and to protest the "white bread" values of one's parents, who likely served Wonder Bread at home. These ideals resulted in the production of some uncompromising and notably bricklike loaves of dark, seedy bread, which probably set back the revival of whole-grain baking a generation. "That hippie texture" is a cross that whole-grain bakers still bear today, along with the widespread belief that whole-grain bread promises rather more nutritional and ideological rigor than eating pleasure.

But whole-grain bread seems to be recovering from its sixties revival and is currently enjoying a reversal of fortune, or at least prestige, with white bread, in a sort of carnival of traditional bread values. Now it is the well-to-do who want brown bread, while white bread is becoming decla.s.se. The public has gotten the news about the health benefits of whole grain. The government's latest nutritional guidelines recommend that at least half of one's daily calories from grain come in the form of whole grains. When you consider that even today only 5 percent of wheat is milled into whole-grain flour, this becomes a challenging recommendation to follow.

America's expanding tribe of artisa.n.a.l bakers, who started out in the 1990s as Francophiles devoted to the white-flour baguette, has begun to take a strong interest in baking with whole grains. Chad Robertson's next book will take up whole-grain baking, and much of his energies are now devoted to research and development of whole-grain recipes. Craig Ponsford, the former chairman of the board of directors for the Bread Bakers Guild of America and the first American ever to win a first prize in the Coupe du Monde de la Boulangerie baking compet.i.tion in France, now bakes exclusively with whole-grain flours, and is outspoken about their benefits. (He told me he could never have promoted whole grains at the Guild without offending its milling- and yeast-industry sponsors, so after his conversion he chose to step down.) The supermarket shelves are stuffed with breads and other products making whole-grain claims, some of them more meaningful than others.*

Even Hostess, the company that, until its recent bankruptcy, manufactured Wonder Bread, has responded to the public's demand for more wholesome and nutritious bread. It developed exotic new formulations that contained not just added vitamins and minerals and fiber, but quant.i.ties of the actual foodstuff itself: whole-grain flour. Well, actually, in most cases they were offering something more like the aura of whole grain, which is not quite the same thing. For example, they sold a "Smart White" bread offering "the fiber of 100% whole wheat," said fiber derived not from wheat or any other cereal grain but from cottonseed, cellulose (aka trees), and soybeans. (The wheat itself was actually white flour.) Then they offered a "Whole Grain White" that you had to get really close to to read the small-print prefix "made with"; it turned out the first ingredient here was still white flour. These products strike me as borderline fraudulent. But Wonder Bread did then come up with one real whole-wheat bread that sounds like a breakthrough in modern food science: "Soft 100% Whole Wheat."

Whole-wheat Wonder Bread! This has all the makings of a happy ending, in which the human quest for softer, sweeter, whiter, and airier bread is married to the nutritional benefits of whole grain. But things are seldom that simple in the food industry. The White Flour Industrial Complex is not about to go quietly into the dark-bread night. How could it, when its mills have been expressly designed to produce the whitest possible flour, splitting off the germ and embryo at the first break? When milling white flour and selling off the nutrients is more profitable than selling flour whole? To leave the germ in the flour would literally gum up the works, I was told by an experienced miller by the name of Joe Vanderliet. This is why it is always removed at the beginning of the milling process, even when making "whole" wheat flour.

"The engineering and the nutrition are pulling in opposite directions," Vanderliet explained. Most commercial whole-wheat flour is actually white flour to which the bran and germ have been added back in. Whether such reconst.i.tuted flour is as good, or good for you, as flour from wheat milled whole on a stone is questionable, but the industry can't do it any other way.

Adapting the reductive logic of industrial bread baking to the complexities of whole grain can't be easy. What do you do about the volatility of the germ? Vanderliet claims that many large mills, including ones he used to work for, simply leave the germ out of their "whole-grain" flour "because it's just too much trouble"-a serious charge, but a difficult one to prove. (So here we are again, not quite certain what is really in a sack of flour.) And what to do about the bitterness of the bran in modern wheat varieties? (Most commercial whole-grain breads cover it up with sweeteners.) Or the difficulty of leavening whole-grain dough with commercial yeast? This last problem was (literally) the downfall of a great many hippie loaves; without a sourdough culture to promote gluten development, 100-percent whole-grain breads tend to rise lethargically and crumble in the toaster. Yet it is hard to imagine the bakers at Hostess taking on the care and feeding of a temperamental culture of unidentified wild bacteria and yeast.

By now I was curious to find out exactly how Wonder Bread solved the riddle of baking a whole-wheat white bread. Was it actually possible to modify the logic of an industrial system based on white flour to produce a genuine and appealing whole-grain loaf? So before the company went belly-up I put in a call to the Texas headquarters of Hostess Brands, managed to get through to the public-affairs office, and asked the young man who answered the phone if I might visit one of their factories to learn how whole-wheat Wonder Bread was made. It was his first day on the job, but he promised to get back to me. I was pleasantly surprised when, a week later, I received an e-mail informing me that a visit to the Hostess bakery in Sacramento had been approved. When I studied the map, I saw that the Hostess plant was only an hour or so south of Dave Miller's bakery-the artisa.n.a.l whole-grain baker for whom Chad Robertson had worked-so I decided I would pay a visit to his bakery after my tour at the Hostess plant. Dave Miller mills his own grain and bakes 400, 100 percent whole-grain loaves a week for sale at the farmers' market. The Hostess plant produced up to 155,000 loaves a day for sale at supermarkets across the western United States. It promised to be a day of extremes.

The Hostess plant occupies a sprawling, one-story industrial building on the outskirts of Sacramento. The smell of bread hits you in the parking lot, pleasant at first, but soon oddly cloying. Before the plant manager escorted me onto the factory floor, he handed me earplugs to m.u.f.fle the din. A single waist-high production line snakes through the dim, cavernous s.p.a.ce, vaguely reminiscent of a wildly ambitious model train set, with loaves of bread in metal pans taking the place of train cars. The line traveled all the way from the silos that store flour out back to the mixing drums, through the dough cutters and shapers, into the proofing chamber, beneath the scoring machine (where a thin jet of water neatly scores each loaf), into the tunnel-like oven, then onto the slicing and bagging machine, and finally the twist-tie-er, which puts exactly four twists into every tie. The same line can produce Cla.s.sic Wonder Bread, or Made with Whole Grain White or Soft 100% Whole Wheat as well as Nature's Pride, a new line of "all-natural"-i.e., no chemical additives-whole-grain and -grainish breads, in roughly the same amount of time: four hours, from flour dump to cooled, sliced, packaged, and twist-tied loaf.

The genius of the food scientists at Hostess has been to alter the ingredient formulas (type of flour, amount of yeast, source of fiber) without otherwise disturbing a mechanized system designed to bake white bread quickly. From the point of view of the bakers running the line, bread is pretty much bread, whether white, whole grain, whole grainish, no-high-fructose-corn-syrup, ton-o'-fiber, or whatever the currently compelling health claim dictates. Though the bakers did complain, cheerfully, about the challenge of getting air into breads that had to contain so much added fiber and minerals-"raising all that garbage," one called it. Many of the company's "healthier" brands are fortified with calcium, a mineral not ordinarily a.s.sociated with wheat, but these days a compelling health claim.

"You're basically breaking up rock and throwing it in your dough," the head baker explained. He was talking about the challenge of adding prodigious amounts of calcium to bread, and his candor was disarming. "It takes a h.e.l.luva lot of yeast to lift all that rock." That's when it clicked that the cloying odor-now upgraded to slightly nauseating-was the smell of yeast, lots and lots of it.

Having by now spent time in bakeries, and done a fair amount of baking at home, I was struck by how similar and yet at once how very different the industrial version of bread baking is. I watched flour and water being mixed into the familiar cement-colored slurry-and yet what are all those other ingredients getting added to the mix? The fifty-pound bags labeled simply "dough conditioner"? The ethoxylated mono- and diglycerides? The four types of sugar (high-fructose corn syrup, mola.s.ses, barley-malt extract, and corn syrup solids)? The wheat gluten and ammonium chloride and calcium propionate and sodium stearoyl lactylate and "yeast nutrients"? And why would yeasts living in such sweet dough need more nutrients, anyway? To balance their sugary diet?

The bakers in charge couldn't tell me the function of the thirty-one ingredients listed on a package of Soft 100% Whole Wheat; they suggested I ask the food scientists at headquarters. But HQ wouldn't let me to talk to their food scientists, ostensibly for fear they would inadvertently disclose proprietary baking secrets. Eventually I was able to ascertain from other food scientists the specific functions of the thirty-one ingredients, most of which fell into one or more of these categories: to back up a health claim; to "condition" the dough so it doesn't stick to and thereby slow the machines; to get as much air into the dough as rapidly as possible; to give the bread the cottony texture and moist cakey crumb consumers expect from the Wonder brand; to protect the bread from staling or molding; and, last but far from least, to sweeten the bread and thereby cover up the bitterness of bran and, even more important, the chemical taste of all the other additives.

Once upon a time not so long ago, most of those chemical additives would have been deemed "adulterants" by the Food and Drug Administration. But after an all-out campaign of lobbying by the baking industry in the 1950s, the FDA liberalized its "standard of ident.i.ty" for bread, permitting bakeries to add dozens of new additives to what had previously been a simple two- or three-ingredient food. Earlier in the twentieth century, a group of experts convened by the International Congress for the Suppression of Fraud (quaint idea!) proposed a legal definition of bread that the loaves I was watching being baked would not have met. "The word bread, without any qualifier, is exclusively reserved for the product resulting from cooking dough made with a mixture of wheat flour, sourdough culture or yeast (made from beer or grain), drinking water, and salt." How far this thing called bread has come!

And yet even after all these novel ingredients have been mixed into the dough, the process still sort of resembles the baking of bread. At one point early in the tour I stepped into the sponge room, where big hoppers filled with wet dough are bubbling and rising like sofa cushions as they undergo bulk fermentation. The only difference from a bulk fermentation in my kitchen or at Tartine is how quickly it happens here. By putting vast quant.i.ties of yeast to work-as much as 10 percent by weight-Hostess can get the great big belch of CO2 needed to raise a whole-grain or super-high-fiber dough in just an hour or two.

Indeed, much of the innovation in industrial baking has gone into speeding up what has traditionally and perhaps necessarily been a slow process. But time is money. So the dough is inoculated with legions of fast-acting yeast to speed its rise; it then gets one set of conditioners so it can withstand rapid handling by machines, and another to speed up (or replace) gluten development, and then it is heavily sweetened, so that even a 100 percent whole-grain loaf will deliver that quick hit of sugar on the tongue the consumer has come to expect from white bread. In the end, what has been removed from industrial bread by the addition of so many chemical additives is the ingredient of time.

Yet there are problems with speeding up whole-grain bread, and they begin with the flour. Many if not most of the new whole-grain white breads on the market are made with a new variety of hard white wheat developed by ConAgra. This is why the bread doesn't look like whole wheat: the specks of bran are white, or whitish. They are also microscopic: The wheat is milled by ConAgra using a patented process called Ultrafine that attains a degree of fineness never before achieved in a whole-grain flour. This resulting flour, called Ultragrain, makes for a softer, whiter whole-grain bread, but at a price. It is metabolized almost as fast as white flour, obviating one of the most important health advantages of whole grains: that our bodies absorb and metabolize them slowly, and so avoid the insulin spikes that typically accompany refined carbohydrates. A common measure of the speed by which a food raises glucose levels in the blood (and therefore insulin, an important risk factor for many chronic diseases) is the glycemic index. The glycemic index of a whole-grain Wonder Bread (around 71) is essentially the same as that of Cla.s.sic Wonder-bread (73). (By comparison, the glycemic index of whole-grain bread made with stone-ground flour is only 52.) So perhaps we really have gotten too smart for our own good.