The following is an excerpt from Frostbite: How Refrigeration Changed Our Food, Our Planet, and Ourselves by Nicola Twilley

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Frostbite: How Refrigeration Changed Our Food, Our Planet, and Ourselves

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My first day at Americold’s warehouse in Ontario, California, began promptly at 8:00 a.m. Outside, it promised to become the kind of blue-skied, seventy-degree March day that makes greater Los Angeles feel like the paradise it plays on TV. Inside, Anthony Espinoza, the facility’s general manager, warned me it was just three degrees in the coolers and between thirty-six and thirty-eight degrees on the dock. “It’s minus ten in the freezer,” he added, radiating good cheer. “That’s the tundra.” My expedition into the artificial cryosphere-the vast synthetic winter we’ve built to preserve our food-began here, with a week of shift work in the refrigerated warehouses of Southern California. Americold is one of the largest providers of temperature-controlled warehouse space, not only in the United States but around the world. Globally, the company maintains 1.5 billion cubic feet of cold, storing everything from ground beef destined for school lunch programs to frozen lobsters on their way to upscale restaurant chains like McCormick & Schmick’s. In Ontario, most of the 100,000-square-foot warehouse is given over to Danone products: pallet after pallet of Horizon chocolate milk, Land O’Lakes creamer, Silk soy milk, and Greek yogurt, much of which comes from a plant just forty-five minutes away. “They focus on creating food,” explained Espinoza. “We focus on making sure it gets to their customers intact.”

Espinoza and his warehouse manager, Kyle Schwedes, had already welcomed two new recruits the day before. “I told them it’s very cold, it’s very physical, it’s very demanding,” said Schwedes. He and Espinoza look for a few essential attributes in warehouse candidates. Interpersonal skills and attention to detail are important, but experience driving a stand-up reach forklift is nonnegotiable.

The other essential test is, of course, how the would-be warehouse worker reacts to the frigid temperatures. “I love the cold,” said Espinoza. “It preserves me! All our guys have a youthful appearance.” (Much to his delight, I had guessed his age as a full decade younger than he actually is.) Still, a lot of people are just not cut out for a career spent inside a gigantic fridge. Later, once I was out on the floor myself, a shift supervisor named Amato took me under his wing. He told me he’d seen dozens of new recruits leave after only a couple of hours in the chiller. “They take off their coats at lunchtime, and poof! They’re gone,” he said. “It’s the rare person that lasts here.”

It’s the rare person who steps inside a refrigerated warehouse in the first place. Over the course of nearly two decades spent reporting on food for national and international newspapers and magazines, as well as for my own podcast, I’ve been lucky enough to visit all sorts of unusual, behind-the-scenes locations, from farms and factories to sourdough libraries, experimental orchards, and military labs. Still, until I began writing this book, I had never so much as peeked inside anything larger than a walk-in fridge. You probably have not either.

The refrigerated warehouse is the missing middle in food’s journey from farm to table: a black box whose mysterious internal workings allow perishable food to conquer the constraints of both time and space. Even those chefs who are proud to know the life story of each steak they serve, or the foodies who insist on meeting the farmer who raised the meat they eat, would never dream of inquiring as to its storage history—or imagine that beef carcasses have to be electrocuted in order to withstand the rigors of refrigeration without toughening up. Similarly, you may be familiar with the full range of lettuce varietals in the bag of supermarket spring mix sitting in your crisper drawer, but I’d be willing to bet you have no idea that the bag itself is a highly engineered respiratory apparatus, designed in layers of differentially semipermeable films to slow spinach, arugula, and endive metabolism and extend their shelf lives. I certainly didn’t.

The cold chain—as the network of warehouses, shipping containers, trucks, display cases, and domestic fridges that keep meat, milk, and more chilled on their journeys from farm to fork is technically known—has become such an essential part of our food system that it is taken for granted. Its extent and operations are opaque even to our elected leaders. During the early days of the COVID-19 pandemic, as supermarket shelves emptied, one industry expert told me that he received a frantic call from a senior official in the British government, asking how many refrigerated trucks and warehouses the country’s food supply depended on.

This inadvertent blind spot is a big—and dangerous—mistake. As I’ve discovered while traveling the world to research this book, it’s impossible to make sense of our global food system until you understand the mysterious logic of the all-but-invisible network of thermal control that underpins it. What we eat, what it tastes like, where it’s grown, and how it affects both our health and that of our planet: these things shape our daily lives as well as our continued existence as a species, and they’ve been entirely transformed by manufactured cold.

In 2012, the Royal Society—the UK’s national academy of science—declared refrigeration the most important invention in the history of food and drink. Judged in terms of its impact on a range of criteria, including productivity and health, refrigeration was deemed more significant than the knife, the oven, the plow, and even the millennia of selective breeding that gave us the livestock, fruits, and vegetables we recognize today. It is also a much more recent development: our ancestors learned to control fire before modern humans even evolved, but our ability to command cold at will dates back little more than 150 years. Mechanical, cooling—refrigeration produced by human artifice, as opposed to the natural chill offered by weather-dependent snow and ice—wasn’t achieved until the mid-1700s, it wasn’t commercialized until the late 1800s, and it wasn’t domesticated until the 1920s.

Today, a century later, nearly three-quarters of everything on the average American plate is processed, packaged, shipped, stored, and/or sold under refrigeration. The United States already boasts an estimated 5.5 billion cubic feet of refrigerated space—a third polar region of sorts. This is an almost unimaginably large volume: the tallest mountain on Earth, Everest, occupies only roughly two-thirds that amount of space from base to peak.

As the developing world begins to build its own American-style cold chains, the expansion of this manufactured Arctic has accelerated. According to the most recent statistics from the Global Cold Chain Alliance, the world’s chilled and frozen warehouse space increased by nearly 20 percent between 2018 and 2020—a leap that still left most of the planet’s citizens provisioned using less than a sixth of the cold-storage capacity required to feed the average American. (The standard domestic fridge, at between twenty and twenty-five cubic feet, is just a tiny closet in the distributed, McMansion-sized pantry it takes to preserve our perishables.) While ecologists and explorers concern themselves with the shrinking natural cryosphere—Earth’s frozen poles and permafrost—this alternate, entirely artificial cryosphere is expanding virtually unnoticed, all around us.

My fascination with the cold chain began about fifteen years ago, when the farm-to-table movement was picking up steam in the media. While my fellow food journalists were writing about feedlots and fast food, or locavores and edible schoolyards, I got stuck on the conjunction. What about the to? What happened between the farms and the tables?

Almost immediately, I realized that my humble home fridge was merely the tip of the iceberg. Considered as a connected whole, the cold chain seemed to me as worthy of awe as the Pyramids of Giza—a continuous monument of engineered winter that has remade our entire relationship with food, for better and for worse. Industry insiders clearly had a grip on its geography and mechanics; a handful of historians had traced particular elements of its evolution; scattered scientists were engaged in analyzing its various effects on everything from the flavor of tomatoes to the contents of our gut microbiome; and, more recently, policymakers have begun to worry about its environmental impact. Yet, to my surprise, no one had tried to tie those threads together into a coherent narrative—a story that could help us understand the extraordinary scope and implications of the refrigeration revolution.

As I pored over my copy of the International Association of Refrigerated Warehouses’ annual directory of member facilities, I couldn’t help but wonder: Where are the Shackleton and Scott of the artificial cryosphere? Why is no one embarking on bold expeditions into its farthest-flung corners, braving its icy wastes, mapping its unexplored contours, meeting its inhabitants, and chronicling its customs? Then I realized that perhaps I should put on some thermal underwear and do it myself. This book is the result.

In the course of my adventures, I have been inside places most of us will never see and met people most of us have never heard of—despite the fact that they stand between us and hunger. As we continue together on the following pages, we’ll visit the landmarks of the artificial cryosphere, from the vast caves where Kraft stores America’s national cheese reserve to the Arctic vault where the future of farming is safeguarded by refrigeration. We’ll tease out cooling’s unwritten history, rummaging through untouched archives and tracking down forgotten pioneers. We’ll get to know forklift operators, fridge designers, a frozen-dumpling billionaire, and the world’s only refrigerator dating expert. Most important, we’ll arrive at an understanding of the true stakes of our refrigerated food system.

Of course, humanity’s mastery of cold has been turned to many other fascinating uses over the past century, from data centers to medicine, air-conditioning to ice rinks. In this book, I have limited my inquiries to food alone: the means by which refrigeration has created the most radical change in how we live. As the Royal Society said, explaining the reasoning behind its decision, refrigeration has been a blessing, “responsible for bringing a more varied, interesting, nutritious, and more affordable diet to an ever increasing number of people.”

But as the developing world undergoes the transformation that the United States underwent during the twentieth century, it is time to make a full accounting of the cold chain’s costs, as well as its benefits. Refrigeration has changed our height, our health, and our family dynamics; it has reshaped our kitchens, ports, and cities; and it has reconfigured global economics and politics. It spawned Tupperware and the TV dinner, it served as midwife to the shopping trolley and the hoodie, and it sounded the death knell for several species. Most urgent, mechanical cooling makes a growing and significant contribution to global warming, based on the power required to run it as well as the super-greenhouse gases that circulate within many cooling systems. With unfortunate irony, the spread of the artificial cryosphere turns out to be one of the leading culprits in the disappearance of its natural counterpart.

To its earliest pioneers, control of cold endowed humankind with godlike powers over the otherwise immutable forces of decay and loss, unlocking limitless abundance by removing the constraints of distance and the cycles of seasonality. Today, our dietary dependence on refrigeration is almost complete—and human control over nature has never seemed less sustainable. Cooking may have made us human but, to misquote Paul Theroux’s utopian protagonist in The Mosquito Coast, is ice really civilization? What would happen to our dinner plates, our cities, and our environment if we cast off its frosty fetters?

First of all, though, what actually goes on inside the (usually white) boxes that house the artificial cryosphere?

Before I was allowed anywhere near Americold’s refrigerated warehouse floor, I had two hours of safety training to complete. Warehouse work is already one of the most dangerous jobs in the United States, and many of those risks can be traced back to the forklift. These little cubes on wheels look like oversize bumper cars with two silver prongs attached, but they are surprisingly tricky to operate. Tweaking the angle of the fork so that the truck doesn’t tip over when reaching for a heavy pallet load depends on experience and intuition. Steering is done using two levers, both of which are incredibly sensitive; on one of them, the controls are also inverted, so that a left turn will take you to the right. “If you want some horror, watch YouTube forklift accidents,” said Anthony Espinoza. “If you crash into the racking hard enough to knock it over, you get a domino effect and the entire roof will come down.”

In addition to the standard forklift-driving and pallet-unloading accidents, the cold-storage environment presents dozens of additional risks. In a frozen warehouse, the floor glitters with ice crystals, leading to slips and falls. The ammonia used in the refrigeration system is deadly. A few years earlier, Espinoza told me, he’d experienced a chemical leak when a pipe was accidentally ruptured by an out-of-control forklift. Within three minutes, the entire dock was filled with a white cloud. “When you see that, you’re seeing death,” he said. “Ammonia wants moisture—it wants your eyeballs and your crevices.”

The biggest challenge, however, comes from the very same quality that makes refrigeration so powerful: cold’s ability to slow everything down. The microbes and enzymes that would normally be spoiling the yogurt and curdling the milk become sluggish in the chilled air, but so do the humans charged with loading and unloading those dairy products. Even computers cease to function in the deep freeze, so companies like Honeywell produce a special range of barcode sensors and laptops equipped with internal heaters and screen defrosters. At minus twenty and below, tape doesn’t stick properly, rubber becomes brittle, cardboard is stiffer—and all those minor obstacles seem more like insurmountable challenges to a cold-slowed brain.

A medical mnemonic describes the effects of excessive cold on the human body as the “umbles”: the underdressed or overexposed individual starts to grumble, mumble, fumble, and stumble. “Cold stupid” is mountaineering slang for the way that thought processes congeal after spending too long at a low temperature. As early as 1895, the cold-storage industry’s first trade journal, Ice and Refrigeration, pointed out that “extreme cold, as is well known, exerts a benumbing influence upon the mental faculties.” By way of example, the author referred to an account of the retreat of Napoleon and his troops from Moscow, during which a doctor noted that, at five degrees, “many of the soldiers were found to have forgotten the names of the most ordinary things about them.” For context, the average frozen food warehouse is held between five and twenty degrees below zero, although specialist facilities for storage of particularly delicate foods such as tuna can go as low as minus eighty; the South Pole averages minus seventy-four during its chilliest months; while the mean temperature at the summit of Mount Everest in winter is a comparatively balmy minus thirty-one degrees.

Adapted from FROSTBITE by Nicola Twilley. Reprinted by arrangement with Penguin Press, an imprint of Penguin Publishing Group, a division of Penguin Random House, LLC. Copyright © 2024, Nicola Twilley.