Twinkie, Deconstructed (19 page)

What’s most intriguing about this underground landscape is what’s missing: the close walls (“pillars” in mine-speak) holding up the ground above, forming tunnels. Here, the roof, 750 feet long and about twenty feet wide, is held up only temporarily by a row of 135, C-shaped, computer-operated, hydraulic steel supports, like forklifts on steroids (putting out 750 tons of pressure each), lined up right next to one another in a long row of sheer, ten-foot-tall strength. The top arms are about fourteen feet long, the feet about eight and a half, and each unit is five or six feet wide. As the digging progresses, the whole shebang is moved along: the digger, the conveyor, and the self-powered supports, a few at a time, thirty-two inches for each cut. The ceiling of shale behind the cut is simply allowed to collapse. This is supposedly safe, but when a chip drops and bangs onto my hard hat, I jump about a foot.

However safe this might be, the wall creaks and cracks continuously. It even splashes, as big chunks of rock split and fall off, contrasting with the otherwise eerie underground silence. My engineer guide explains that this is good rock mechanics. You take out tons of rock, the land above presses down, the rock cracks. “You don’t want stress to build up,” says Tim. “It has to be relieved, periodically, in small amounts, just like with us,” otherwise it might just all cave in.

The material is coaxed along the steel conveyor, into a small crusher, and onto the eight-mile-long rubber conveyor belt for the trip to the soda ash plant, our next destination, where it will emerge into a neat pile.

A few prairie dogs dart in front of my car, narrowly escaping with their lives, as I drive to the plant. In fact, I’m driving over the very spot I was under all morning, looking for where this Twinkie ingredient comes from. The next step is to make it into some useful things, like soda ash and sodium bicarbonate. The soda processing plant must be the whitest plant in the world, and it hasn’t snowed for weeks. All the buildings and machinery are dusted with trona or soda ash, contrasting beautifully with the dark brown, vast, open, classic western landscape. Sagebrush and soda.

T
HE
G
UILLOTINE, THE
A
RM, AND THE
H
AMMER

Some food sources are planted in the spring and harvested in the fall. This one was planted 50 to 60 million years ago, and has been constantly harvested since 1952. Lake Gosiute, an eight-thousand-square-mile, Eocene epoch subtropical lake, filled and evaporated repeatedly, and trona formed thanks to the introduction of considerable amounts of carbon dioxide (either from decaying plants and animals or from hydrothermal activity—no one knows). This left behind a rock layer of ancient marine deposits and 150 billion tons of trona in a dozen seams sandwiched between layers of shale and sandstone that came to be known as the Green River Basin.

Nowhere else in the world is there anything quite like this deposit, a thousand square miles of trona. Though only about a third of it is recoverable, there is enough for world demand for more than four thousand years to come (based only on current mining techniques, that figure is reduced considerably and open to debate). FMC alone processes nearly 7 million tons each year into soda ash; all the mining companies together have the capacity to remove about 15 million tons each year.

But the stats don’t tell the whole story. Why is this rock product called soda? Where did we get soda ash before these Green River mines started in the 1950s? And, finally, the fundamental question: how and why did we begin eating this particular rock, putting it into bread, muffins, and, of course, Twinkies?

Soda ash is all about sodium. The term “soda” denotes something that contains sodium (sodium carbonate is also known as sal soda and washing soda). For thousands of years going back to ancient Egypt, crude soda, whether for glass or mummy-making, was made from plant ashes, notably seaweed and trees, giving it the common name soda ash. People simply burnt vegetable matter and then poured water over the ashes to leach out the soda. Early American colonists cut enormous quantities of trees to make soda ash for soap-making and glass-making. They were so productive that they exported eight thousand tons to Europe in 1792 (this was mostly potassium carbonate, or pearlash, baking soda’s predecessor). It is possible that more trees were cut for chemicals than for use as fuel; certainly that is what deforested much of Europe and England. Another source that fell into political disfavor was Spanish barilla, a bushy plant that grows in coastal salt marshes. In addition to a political desire to cut dependence on American exports, this deforestation, coupled with increasing demand, is what drove the Europeans to try to develop an industrial source of soda ash.

In 1783, King Louis XVI asked the French Academy of Science to offer a prize of 100,000 francs—probably worth close to three-quarters of a million of today’s dollars—to anyone who could develop such a process. In response to that, a Frenchman named Nicolas Leblanc managed to create the modern, artificial source of soda ash, the predecessor source to Green River, but he was unable to capitalize and build plants due to what might be described as acute political problems (among other things, his principal investor was guillotined).

Leblanc had designed a two-step process that called for mixing sea salt and sulfuric acid, and then heating the resulting sodium sulfate with charcoal and limestone. Unfortunately, with these plants, a lot of hydrochloric acid and CO
₂
went up the smokestacks (acid rain is nothing new), more hydrochloric acid polluted streams, and copious amounts of black ash and partially burnt coal dumped in surrounding areas polluted the land. England, which had embraced this process, became both the leading chemical producer in the world and one of the first countries to pass an antipollution law, the 1863 Alkali Act. Because of the pollution, the Leblanc process became unpopular just as the product was becoming more in demand, especially by American cooks. This was thanks to a couple of fellows, Church and Dwight, whose product had a little logo that you might recall seeing from time to time: the arm and hammer.

In the 1830s, Dr. Austin Church perfected a way of making inexpensive sodium bicarbonate by cooking expensive English artificial soda ash over coal fires for three weeks at a time, a process that produced what they called salaratus (“aerated salt”). In 1846, he and his brother-in-law, John Dwight, began selling small, retail bags of salaratus—the first baking soda—with great success, in large part due to the fact they now had not only a superior, consistent product, but one that sold in 1850 for pennies a pound versus something that had previously cost on the order of $1.25 a pound. Their current little yellow package still carries the 1846 date, though their claim of “natural” is a bit of a stretch.

Church and Dwight continued to search for a more efficient process in order to meet increased demand. Serendipitously, the first synthetic sodium carbonate plant opened in the United States during this period. The process, developed in 1861 by Belgian scientists Ernest and Alfred Solvay, used a chemical reaction (originally reacting salt with ammonia and limestone, later just using ammonia and coal) that created impure sodium bicarbonate as an intermediate step in the process to make artificial sodium carbonate, or soda ash, which has always been more in demand. Until the Green River mines became operational in the early 1950s, all of our sodium bicarbonate was made using the Solvay process. Now, none of the U.S. soda ash is made this way, but the Solvay process still serves the rest of the world.

Still, some elements of the original product remain unchanged, especially its famous logo. When Dr. Church’s son, James, joined the business in 1867, he brought along the logo of the Brooklyn mustard and spice business, Vulcan Spice Mills, where he had been working, despite its apparent lack of connection to baking soda. It depicted the arm and hammer of Vulcan, the Roman god of fire and metalworking, the very same logo Church & Dwight still uses today for its brand, Arm & Hammer
^®
.

T
OWER OF
B
UBBLE

The newly mined trona, at the end of its eight-mile underground conveyor belt, is carried up and spewed onto one of many three-story-high piles next to the soda ash plant. Long, angled, white conveyors, looking like elevated subway tracks, connect several groups of buildings. Each building makes slightly different versions of soda, mostly by dissolving it and then concentrating and drying it to both purify it and to create crystals of a desired size and shape, much like a sugar or salt plant. FMC alone has ten plants here; our destination is the sesquicarbonate, or “sesqui” plant that makes the sodium carbonate that gets processed into sodium
bi
carbonate. White icicles dangle off roofs and hissing valves, suggesting dainty gingerbread houses. The icicles, while not edible, are not toxic. They better not be—after all, much of this stuff goes into our food.

Some of the pipes, carrying six thousand gallons of sesqui slurry per minute, lead to the nearby sodium bicarbonate (or “bicarb”) plant, where the plain sodium carbonate will be purified and given some more carbon to become sodium bicarbonate—baking soda, one of the three components of baking powder—in a matter of hours, a day or so after it was raw ore.

Two things welcome you as you enter FMC’s bicarb plant headquarters: an informal glass display case in the entry hall that holds dozens of boxes of Little Debbie cakes (it is nice to see an ingredient in its final form not far from its raw source); and the friendly smile of Glenda Thomas, the chemical engineer who runs this place.

The first stop on the plant tour is the small, plain pipe where the soda ash slurry, bicarb’s raw material, enters the building. The pipe seems inconsequential, not even a foot in diameter, for a plant that can make seventy thousand tons of bicarb a year. Thomas opens a test hole in a big pipe and takes out a cupful from the torrent to examine. It feels slippery and grainy, a soapy salt solution—a welcome, sensual surprise because so much of the processed materials are in fact hidden in the pipes and ovens and myriad stainless steel devices.

Giant cone-bottomed hoppers fill the room, suspended way above the floor. When viewed from underneath, they look like missiles stored in launch readiness. After a climb to the top of the seven-story carbonation tower, the central and most important point in the process, we can see the actual carbonation take place, transforming this stuff that was just mined into a gold mine of a food product. It simply takes lots of gas, yet another Western resource.

Carbon dioxide comes in via truck from one of a few nearby processors, such as ExxonMobil’s Shute Creek natural gas facility, a site that includes hundreds of natural gas wells that are no more than pipes sticking out of the ground with valves on them. ExxonMobil separates the natural gas out and pipes the rest, the CO
₂
, to a processor that cleans out the remaining methane and sulfur, compresses it, liquefies it, and trucks it over to FMC.

It is hard not to think of this towering tank as a giant seltzer bottle. The CO
₂
bubbles up, almost boiling, in a soup of sodium carbonate and water. Local gas and rock are mixed here to make one of the most well-known and widely used household chemicals in the world. From Wyoming to your teeth, your cupboard, your fridge, your cake. And your Twinkie.

A few more ladders and catwalks lead to the “dry” side. The liquid enters the dry side through big pipes and is sent floating down an eight-story cylinder of hot air. Now looking more like moist gravel, it is further dried, cooled, and screened for various crystal sizes in a series of rather compact boxes. Different crystal sizes are desired for various uses: big for animal feed (the most common use—because corn-fed cattle get indigestion of sorts, seeing as they are natural grass eaters, not grain eaters); small for water softening. The crystal size influences the rate of the chemical leavening reaction, too. Every aspect has to be just right so that when wetted and reacted with the phosphoric acid in baking powder (or the vinegar in your kitchen), the bicarb releases the carbon dioxide it just picked up here. It all balances out.

We make our way to the end of the production line, and once again Thomas opens a pipe to check out the flow, but this time she scoops out and proudly pours some still-warm, absolutely freshly processed sodium bicarbonate, soft and smoother than talcum powder, onto my hands. I taste it, waiting for the rush, the revelation that every foodie gets from tasting food at its freshest, at its source—the milk drunk while standing by the cow, the wine sampled at the winery—and I am not disappointed. It is the freshest, best-tasting bicarb of soda I have ever had. It is hard to get a sense of terroir that this taste conveys, the taste of the local climate and soil, as this is not fine wine. And, in fact, it is very, very hard to imagine this as having been a rock or a gas, underground and nearby, only days earlier, yet here I am eating it. What’s more, this rock powder needs to be mixed with some more powders made from rocks in order to make baking powder. And at least one of them comes from yet another mine just a few miles away.

CHAPTER 16

Phosphates: Sodium Acid Pyrophosphate and Monocalcium Phosphate

A
s I begin walking across the parking lot behind my historic hotel in Soda Springs, Idaho, a loud whoosh stops me in my tracks. I whip around to see a geyser of carbonated water shooting up a hundred feet and splashing lazily back onto the red-orange-yellow bed of dried minerals in the adjacent lot. There is no shortage of “soda” (as the locals call it)—a reminder of the geologic treasure underground out West.

I’m here to see where another mineral, phosphorus, comes from—the source for phosphoric acid, the stuff that eventually makes the “phosphate” in monocalcium phosphate (MCP) and the “acid” as well as the “phosphate” in sodium acid pyrophosphate (SAPP), the two remaining ingredients that join baking
soda
to make up baking
powder
, or chemical leavening, the very incarnation of modern baking. What that means is that I’m on a trip to see where some rocks we eat come from.