Twinkie, Deconstructed (20 page)

The way it works is this: phosphoric acid is mixed with two bases, limestone and sodium carbonate, to make two new chemicals—and, voilà, baking powder. When baking powder, this mixture of ground-up rocks, is wetted and heated, such as in making, say, Twinkies, the acid and bases react ( just like the vinegar and baking soda experiment of your childhood), to create nice little gas bubbles that make cakes like Twinkies so light and airy. As exciting as that is, though, nothing is quite as dramatic as wrenching elemental phosphorus from the earth in order to kick-start the whole process.

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OCK

Phosphorus is the source of some of the most common chemicals used in everyday life. It is one of the seven elements necessary for life, and the atomic bonder of the amino acid ladder rungs in DNA (the phosphorus pros showing me around like to joke, “Phosphorus is what holds your genes up!”). It’s also what puts the glow in tracer bullets and causes artillery shells to explode, because it bursts into flame when it makes contact with air. So it does seem odd that it’s part of the Twinkies recipe.

Baking powder is only one of the more common uses for food-grade phosphoric acid, which is used in hundreds of ways (among them: setting jam, jelly, and chocolate pudding; gelling processed seafood like surimi [sea legs]; preserving meat in sausage; refining sugar, emulsifying processed cheese, cleaning poultry), and much of it is used as the soft-drink ingredient that gives colas their distinctive tanginess. Phosphoric acid is actually one of the few individual ingredients listed on the Coca-Cola
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label, right between “caramel color” and “natural flavors.” Surprisingly, though, it is not a major ingredient—less than 1 percent in most food products, used sparingly, much like citric and acetic acids. Industrial uses range from fertilizers to fire retardants to water purification; naval jelly is one form familiar to handypersons as a rust remover. Phosphoric acid does seem like an unlikely food ingredient, especially in something as delicate as cake. It is even harder to believe that it starts out as soft rock.

Dirt versus German Nuns’ Urine

The mine of the flammable rock is about eighteen miles up the highway and a few thousand feet higher than Soda Springs, tucked amid softly rounded hills dotted with pockets of trees that form the western edge of the Rockies. Barley fields carpet the valley.

A couple of mining engineers drive me into Monsanto’s Enoch Valley Mine, where our sizable Chevy Suburban feels minuscule dodging the huge eighty-five and hundred-ton Caterpillar 777B and 777D trucks that are speeding by, dumping ore, shale, and soil. By dodging, I mean that the engineers in the car recognize that not only do the big monster vehicles have the right-of-way, they have the ability to crush us without even noticing. The car is quiet as we swivel our heads with tense concentration, on the lookout for the oncoming vehicles as we make our way into the 1,800-foot-long and 350-foot-deep pit. The pit is about 1,000 feet wide. The wheels on these ore trucks are so large that I don’t even reach the top of the wheel rim when I stand next to one, boots and hard hat included, and I’m close to six feet tall. The ladder for the driver has three steps just to get onto the bumper, and two more, larger ladders to get from there to the cab.

Two big scooper machines, one looking like a regular front loader on steroids, the other a giant crane, are digging and dumping dark dirt into the trucks at a furious pace. The scoops (the buckets) are so big that at over twenty tons each scoop, they fill the trucks in four dumps. A minute or two later, the trucks are rushing off again. The pit is a scene of constant motion that fairly sings, “time is money.”

“This is it,” says David Carpenter, exploration geologist and one of the mining engineers, proudly pointing at my feet. All I see is dirt. I’ve traveled to the far reaches of the West to see one of the most exotic minerals around, and, now that I’m here, I’m a bit let down to realize that phosphate ore, which is a soft rock, looks remarkably like plain old black dirt. It crumbles easily when you pick at it—or run at it with a bulldozer the size of a small house. It is called calcium fluorapatite, a fancy name for calcified tropical sea creatures and plants, Pleistocene-era plankton, among others, forced near the surface during the basin and range formation period. The miners call it just plain apatite. I resist the urge to ask them if it is
bon
.

Thirty percent of the nation’s phosphate reserves are found here, in what’s known as the Western Phosphate Field, within a hundred-mile radius of Soda Springs, Idaho. It was discovered by Wild West gold miners in 1889. The current annual output is more than 6 million tons, divided between fertilizer factories and the big “thermal” phosphorus plant down the road. (The reserves should last well into the 3000s.) It wasn’t always mined this way, though. This is a modern source, not the original source of phosphorus, the one where phosphorus was discovered.

Back in the mid-1600s, while amateur German alchemist Henning Brand was a medic in the German army (presumably during the Thirty Years’ War), he got the idea from watching the life ooze out of mortally wounded soldiers that the “stuff” of life must be in the liquids of the body. He thought blood research, though common, was “of the devil,” so he chose to look at other body fluids, which led him to experiment with urine. (Yes, urine.) In search of the purest, holiest urine he could find, he convinced some nuns near Hamburg to collect and donate their urine, which he then distilled. In 1669, after years of experimenting, he managed to boil the urine in the absence of air down to a ball of waxy goop that either burnt up immediately or glowed, depending on the purity of the “ore.” Legend has it that he took a glowing, burning ball into his bed to see if he could soak up some life from it as he slept, but all that happened is that his bedclothes caught fire and he suffered some serious burns. Such an ignominious result for the first positively known discoverer of an element.

Arc Furnaces and Attack Tanks

As difficult as it may be to refine ore, it does seem to be an improvement over urine.

The Monsanto phosphate plant where the trucks deliver the ore is located a few minutes outside of Soda Springs, Idaho, across a much-used freight track where long tank-car chains rumble along, day and night. The plant, at the end of a mile-long conveyor belt, is surrounded by several thirty- or forty-foot-high piles of raw ingredients—a few perfect jet-black cones of coke (pure carbon from cooked coal) and a few similar but light sand-colored cones of silica (quartz). The ore is a longer but lower pile of what looks like a highway ramp construction site, because it just looks like dirt. Coke, silica, and ore: the basic urine-free phosphorus recipe for Twinkies leavening.

The immense mineral wealth of Wyoming and Idaho make this the ideal location for the plant. The coke, silica, and power (coal-generated) come from nearby mines. Railroads crisscross the entire region, as does the Oregon Trail. This is the industrial heartland, although signs along the highway proclaim it the “Barley Capital of the World.”

This elemental phosphorus plant is the last and only one in North America, partly due to the cost of electricity (which is free in some foreign countries, an upsetting fact for this plant’s owners) and partly due to the environmental concerns triggered by its toxic discharge (another company’s plant, which closed in 2001, is now a Superfund site, thanks to elevated levels of arsenic and other pollutants found in local groundwater). This whole process may soon be rendered obsolete by a newer, technologically advanced “wet process” phosphoric acid–making technique. But this process is amazing to behold.

The plant is so big that I have to drive almost a mile to reach the back, where the ore is baked and purified. It rolls through a rotating kiln, twenty feet in diameter and 325 feet long, that bakes it at 2,500°F—so hot that the rock turns into little bumpy stone bits called nodules. The kiln is so massive that observing it from nearby is like watching a football field rotate. It is here that the phosphate ore begins to shed its dirtness and edge toward elemental pureness.

The nodules drop onto one of the country’s biggest conveyor belts, after which it ascends to the top of the electric arc furnaces (at nine stories high, the world’s largest) and tumble along with a precisely measured, gravelly mixture of coke and silica from the piles outside—two more rocks for leavening, but these we don’t eat (they just act as catalysts). Another cooking session begins—this one even hotter. A lot hotter.

As I leave the bright sunshine outside to enter the dark, blackened furnace area, Steve Ahmann, the furnace supervisor, puts on his wraparound sunglasses (and earplugs), which serves as a warning that I’m about to see something spectacular. A skinny young worker with thick, dark goggles and enormous, heat-shielding gloves is tending a magazine-size access hole about halfway up the thick-walled furnace that reveals a sun-like inferno. He is energetically scraping and pushing the melted mass inside with fifteen-foot-long poles, manipulating them through the tiny window, sending off goopy by-products (including vanadium, which is sold to steelmakers). “This job is a rite of passage,” Ahmann says. Indeed, a kid straight out of engineering school would do well to work in this Hades awhile, to witness the chemical reaction firsthand, to develop an appreciation for real heat. At these temperatures—11,000°F, close to that of the sun’s surface, and just what it takes to melt any and all known materials—the chemicals release their bonds and a plasma forms. Here, rock is instantaneously liquefied in the name of baking powder.

No oxygen is admitted to the oven, so the phosphorus doesn’t burn. It escapes out the top as gas in a maze of tubes and scaffolding that gleams in the intense mountain sunlight. As it cools down into a precious, honeylike liquid, it is sent through airtight pipes into waiting railroad tank cars where it is kept from bursting into flames by a protective blanket of water. The railroad cars stay parked for a while to allow for the liquid to cool down to its “freezing” point (about 140°F) so it will solidify, making it safer to transport.

In the nearby quality control lab, technicians proudly display their recent take: a collection of beakers with an inch or two of what looks like dark yellow wax on the bottom, covered by a few inches of water. These beakers sit in what looks like a large picnic cooler—which no one gets near unless they are wearing face masks and gloves, as the slightest exposure to air could cause it to burst into flames. Dangerous stuff, this food ingredient. Security here is tight, because pure phosphorus is worth thousands of dollars an ounce on the street, one tech says, stemming from the fact that it is a helpful part of meth production. However, he adds with a grin, if anyone did steal some, the culprit would probably be found at the local emergency room within hours, covered with burns.

The lab techs are not about to sacrifice any of their precious liquid just to show a visitor how flammable it actually is. For that, a burly engineer on a bridge over the railroad tank cars dons a massive, silver, asbestos suit, complete with cylindrical helmet. Looking like a National Geographic volcanologist and playing the Soda Springs, Idaho, version of a vintner sampling a barrel of his wine, he waddles out over the railcar, where a feather of steam is wafting temptingly out of the manhole-like opening, while I peek out nervously from behind a thick steel panel where I have been directed to hide. He dips a narrow siphon tube down through the protective layer of water and lifts it way up, allowing the pure phosphorus to stream back into the tank. It starts by pouring, looking and acting just like water, and after six inches it is flaming.

Indeed, this is what innocuous, everyday baking powder is made of, but most of this elemental phosphorus is used to make acid for Monsanto’s Roundup
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, the most common herbicide in the world (the one that Monsanto’s genetically modified corn and soybean plants resist). Trainloads are headed to Innophos’s Nashville, Tennessee, plant to be processed into phosphoric acid in what they call the thermal process. There, this elemental phosphorus is burned in huge towers and the resulting smoke/gas is sprayed with water to make phosphoric acid. It is as close to pure as anything can be.

Phosphoric acid can also be made directly from North Carolinian or Moroccan ore with the newer and more common “wet process” that became popularized worldwide in the 1990s. At Innophos’s Geismar, Louisiana, acid plant, phosphate rock, which is loaded with calcium, is reacted with sulfuric acid to form “green” phosphoric acid and calcium sulfate, after which the calcium sulfate (aka gypsum, used to make common plaster) is removed. The ability to filter and purify this acid enough to use in food is big news, a technological leap that only recently occurred and is likely, due to increased costs and environmental concerns, to become the only way we get phosphoric acid in the future.

Tellingly, the big tank used for the reaction is called the attack tank. When I ask a plant manager at another plant if he can sell the calcium sulfate, he mentions that, no, the stuff from his plant is “just a little bit radioactive, thanks to some uranium that happens to be in the ore. We just bury it back in the mines.” That’s much better than using it to make radioactive wallboard (only pure, mined calcium sulfate is used in food like Twinkies). One plant alone sends 250,000 pounds a year of fresh, pure phosphoric acid to food and chemical plants around the country.

But no matter the type of acid, it is not yet ready for Twinkies’ baking powder. For starters, it is still a liquid. It will be transformed into a tame, safe, white powder in Chicago at Innophos’s phosphate plant. But two other ingredients need to get there, too: lime and sodium carbonate.

Always Keep Your Rocks from Starting Fires

Limestone is mined from caves dug into the side of rolling hills in a gentler landscape than Idaho’s—the green land around the Mississippi River, a bit below St. Louis. Since the early 1900s, the Mississippi Lime Company of Ste. Genevieve, Missouri, has operated the biggest lime facilities in the country here: over one thousand acres of underground rooms eighty to one hundred feet deep. They produce more than a million tons of limestone a year, yet another rock source for Twinkies leavening that comes from ancient marine deposits. The limestone is removed by giant trucks, similar to the phosphate ore trucks in Idaho, that drive through immense, cavelike openings in the side of the limestone mountain. Calcium lime is one of the most essential chemicals in the world, used in the construction, steel, water treatment, chemical, pharmaceutical, paint, and paper industries as well as, of course, food. This is the calcium source for one of the leavening products that will be mixed in Chicago—the calcium in the monocalcium phosphate.