Twinkie, Deconstructed (22 page)

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Salt is the most common and probably the oldest-known food additive. The first settlements of civilization were often made near salt outcroppings, licks that attracted animals and, as a result, our ancestors, who were interested in hunting said animals (hunters ate the salt their bodies needed by eating fresh meat). By 2000
B.C.
our ancestors were salting meat, fish, and vegetables—including olives—to preserve them and to satisfy their healthy craving for salt. Salt played a major role in world trade among the ancient Greeks, Romans, and Chinese as much as 2,500 years ago, and in northern Europe since the 1300s, primarily for shipping fish. Wars were fought over it, and it was once as valuable as gold (early Chinese coins are said to have been made of it). Genoa and Venice rose to prominence as centers of the salt trade (and Silver Springs, too, in its own way). Through the centuries, the message has been clear: salt is not to be taken for granted.

While salt is also one of the basic tastes (salty, sweet, bitter, sour, and umami) and is necessary in our diet—our cells need it in order to function chemically—it is used as much if not more to simply enhance flavors, even sweet ones, like chocolate. That’s why your chocolate fudge and cake recipes almost always call for a pinch of salt. In Twinkies, salt actually combines with sugar to make the cake and filling taste sweeter. But that’s not all it does.

In Twinkies and in most home recipes for sponge cakes, salt is a functional ingredient, classified as a “processing aid,” which means it enhances not only the flavor, but the texture as well. Salt helps bind the dough, helping provide uniform grain, texture, and strength, which allows the batter to hold more water and carbon dioxide and thus to expand more easily. Salt is not in Twinkies as a preservative, despite its historical pedigree for that.

Salt helps in as many as sixteen other essential food functions (one source at Morton says twenty-one), such as fighting bacteria and mold growth (a good bacteriostat, it is a traditional wound cleanser), activating and “setting” food coloring (think red hot dogs and hams; it is used extensively in textile dyeing, too), creating texture and rinds for cheese, acting as a binder for sausages, and, of course, as a preservative (think pickles and cabbage, as well as butter and fish). It works by absorbing moisture from bacteria and mold through osmosis, killing the cells or at least preventing them from reproducing. You add salt to bread dough to help control the yeast/sugar fermentation action (it acts as a chemical buffer or neutralizer) and to thus cut down on the big “voids,” or bubbles. All of this is such a far cry from mere taste that it seems like salt doesn’t get enough credit. Despite all of these chemical capabilities, salt is so benign that it is, in a way, the model for the large (seven hundred items) FDA class of food additives “generally recognized as safe” (GRAS), even though some argue that consuming too much of this household chemical can lead to increased blood pressure and heart disease.

The demand for salt is incessant: more than 200 million tons are mined annually worldwide. At more than 45 million tons per year, the United States is by far the world’s biggest producer. Fewer than a dozen companies produce salt in the United States, and most are neighbors at the various underground salt deposits (born of ancient, dried-up seabeds) around the country.

Salt seems simple to us because it is common and familiar, but, in fact, these humble crystals are one of the most important industrial chemicals in the world and a key part of the modern industrial web. In 2003, according to salt industry experts, over two-thirds of the salt produced went to the chloralkali industry for transformation into other chemicals—notably chlorine via electrolysis, which is also used to bleach the cake flour in Twinkies (as described earlier) and to make the lye (sodium hydroxide) that is used to process a number of other Twinkie ingredients. Only about 5 to 6 percent of the salt produced is used for food products; 8 percent of evaporated salt goes to highway deicing, 12 percent to water conditioning, and 6 percent to agriculture. Its thousands of industrial applications include roles in making aspirin, plastic, paper, ink, leather shoes, dyes, shampoo, rubber tires, vinyl seat covers, catalytic mufflers, steel and aluminum manufacturing, gasoline processing, tile glaze, adhesives manufacturing, and on and on—the list is estimated at fourteen thousand specific applications. This range stems from the fact that most chemicals are used to make other chemicals, and salt is one of what scientists call the basic chemicals (along with petroleum, sulfuric acid, lime [from limestone], phosphates, nitrogen, and oxygen) that are used to make just about everything else, including other food ingredients.

What a twist of fate it is that such a common, chemically neutral and nutritionally important ingredient is made from a highly reactive chemical (sodium) and a corrosive, even poisonous chemical (chlorine). But that’s what these inorganic salts are: the boring, stable, safe result of a marriage of materials that in their elemental states are often highly reactive, which is why they get together in the first place.

Table salt is one of the least processed food additives (the “processing” it undergoes is primarily to separate it from other rocks). Because it is itself a mineral, it never goes stale and, contrary to popular belief, it doesn’t taste any better or fresher if you grind it with a salt mill (though finer crystals dissolve faster, increasing the seasoning’s intensity). Only sea salts that have not been purified, and thus are still bound with other minerals from seawater, taste different from regular table salt (fleur de sel has even more minerals than regular sea salt, hence its pronounced flavor). Salt is everywhere, it seems, in one form or another.

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Dan Border, Morton’s facility manager, drives me a few miles through rolling, partially wooded terrain to show me where the salt comes from, which just happens to be prime upstate New York dairy farm country. Over the years, Morton bought the mineral rights to a few small dairy farms around their Silver Springs, New York, plant to provide access to the giant salt deposit underneath, putting in unobtrusive salt mining wells and pipelines without disrupting the local landscape. We thread our way through the groves of trees lining a snowy country road, and find ourselves at a fence gate that opens to well-maintained field lane.

Even though Morton owns it, a farmer still grows corn and hay there. Several brand-new blue sheds, placed a quarter mile apart, which shelter wellheads and pipeline valves, are all that interrupt the natural landscape. A group of connected wells is called a gallery, and the few along this pipeline feed brine back to the plant. Once the valves are in, engineers stop by routinely to check them. The fields themselves are left to the farmers and animals—cows and deer, mostly. There is a pretty pond off to the side and a lot of large, felled trees. It is evident that Morton is not the only builder on this plot of land: it shares the role with beavers, one of whom, not to be outdone by the guys from Morton, has built a beautiful and enormous lodge near a very sizable dam.

This particular salt deposit, a remnant of the layer that made the oceans salty, is 2,400 feet deep at this point (not quite half a mile), about 100 feet thick, and spread over about four states: New York, Pennsylvania, Ohio, and Michigan (and Ontario). Other major deposits are found around Texas, Oklahoma, Kansas, Louisiana, North Dakota, a few spots in the Southwest and California (Death Valley), and western Canada. (Almost all of Morton’s pretzel salt comes from a mine in the aptly named town of Grand Saline, Texas.) However, the layer of salt is close to the surface only in some areas, and that’s why upstate New York is one of the oldest and most successful American salt-producing areas. The purest part, “the salt zone,” the stuff that the miners want, is only ten to fifteen feet thick.

We pull up to one of the new, trim, unpretentious blue sheds at the edge of the field and forest. Inside are two small Christmas trees of pipes and wheels and levers and gauges, much of which is wrapped in insulation.
This is it?
I think. The setup is so unassuming that except for the ten-inch pipe surrounded by concrete jutting out of the ground, it suggests a heating and cooling setup in a suburban garage rather than the high-tech mining operation that it is. Flowers of crystals abound on some of the simple plumbing at the wellhead, a mineral looking so much like ice it is hard to think of it as food.

A humble red plastic bucket, crusty from previous samplings, hangs from a small spout, offering a taste. Who wouldn’t want to taste fresh salt as it comes out of the earth, direct from 2,400 feet below, on a winter afternoon, in the middle of a field? No pucker is as serious as the one produced by this water, dark gray with salt—and this pucker lasts—ten times as salty as seawater.

The art and the goal of the miner is to get as much salt into the brine and thus up the pipes as physically possible. That works out to about 2.6 pounds of salt per gallon of water—and this is at hundreds of gallons per minute. Too much salt and solids drop out. Too little, and it’s inefficient to crystallize. It can take a few years of tuning the process to get the pressure just right and to find the purest salt in the deposit. As such, solution mining is fairly complex.

First, you drill two vertical wells into the salt deposit as much as a mile apart, and line them with steel and concrete to protect the local soil and groundwater. Then, you connect the two vertical wells with a horizontal bore, a feat of technical derring-do involving a torpedo-like, remote-controlled, steerable, self-powered, thirty-foot-long drill with rotating claws on its tip. The digger goes down the ten-inch pipe and takes a gentle turn in order to channel down into the middle of the salt deposit, reaching all the way over to the other vertical well. Imagine the challenge of sending this digging device down one pipe, through a few thousand feet of salt and then still managing to “hit” the second well—a minuscule, ten-inch-wide target a mile away. It must seem like directing a space probe to Mars, or at least like playing a very, very slow and expensive video game. (This same technology—directional drilling—enables the oil companies to dig under the tundra of the Arctic National Wildlife Refuge in Alaska from a reduced number of slightly remote platforms.)

Once the hole is drilled, water is pumped down the well (called an injection well) from the shed at a few hundred pounds of pressure. It dissolves and soaks up salt as it goes, working its way through the freshly drilled channel in the salt deposit. The stream of brine can be as much as two hundred feet wide near the injection wells, but narrows like a teardrop as it nears the second well; pressure forces the saturated brine to flow right up to the surface.

From that point, the brine flows along the pipeline a few miles back to the plant, where it is joined by other raw brine from the twenty-five or so other wells nearby. Other than a small gap in the trees here and there, which indicates where a pipeline lies underground, the gently rolling landscape is rural and undisturbed, peppered with prosperous dairy farms.

After all this effort, the brine ends up behind the plant, pouring rather unceremoniously from a big spigot into what looks like a large, shallow swimming pool. If you snuck a swim there you wouldn’t need to worry much about sinking, it’s so dense with salt: the Dead Sea of Silver Springs, New York.

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Here’s where salt mining gets more complicated. Instead of being allowed to evaporate naturally under a hot summer sun, which is not very efficient in places like upstate New York, the brine feeds into a group of several five- to six-story-high, cone-bottomed, sixteen-foot-wide cylindrical vessels called evaporators, evaporator pans, or, more literally, forced circulation pans. These pans are cleverly designed to boil brine in a fancy heat exchanger made of a network of steam-heated titanium tubes. But “pan” is a misnomer—from the bottom they look like sixteen-foot-wide rocket ships encircled by gantries, or in this case, steel catwalks and staircases. I climb up five stories with salt engineer Dennis Grove—these things are
tall
!—on steel catwalks and steps (and down again and up again and around and down again and up again) to peer into a small porthole encased in thick glass at the top of this rocket ship. Though I am half expecting to see an astronaut’s helmeted head and a gloved thumbs-up, I’m satisfied when only thick, dark gray-brown concentrated salt water splashes against the glass and drips slowly down. This, and what follows, is basically the same method developed here in 1884 by Joseph Duncan, Morton’s predecessor, with only modest modern updates.

From there, condensed, white brine flows rapidly through a series of open tanks, giving new meaning to the term “white water.” The impurities float off; the newly washed, dense salt crystals drop to the bottom and are piped out onto three rotating filter dryers in the noisiest room, where a 400°F blast zaps the last of the water from the salt mixture in half a minute. The salt looks kind of clumpy and heavy, not powdery, so it’s not done yet. More blowers and more dryers await around the corner. At this point it can be conveyed by open belt conveyors or augurs (screw conveyors in pipes) to various processing points depending on the kind of salt being made. When little white piles of spilled salt accumulate beneath them, they are quickly swept up by workers.

Once dried, the slightly brown crystals form small cubes that reflect light so well they appear white. They are screened for consistent size on vibrating trays and then poured onto concave conveyors. Minuscule amounts of various additives may be mixed in—a mere dusting—as the salt passes through; things like potassium iodide (for iodized table salt) and/or an anticaking or free-flowing agent such as sodium silicoaluminate or calcium silicate, the stuff that keeps it pouring when it is raining, as the enduring Morton trademark says. Some salt is ground as fine as talcum powder for the bakeries, which demand the fast-acting quality.