How the Fridge Changed Flavor

Save this storySave this storySave this storySave this story

It was the most talked-about meal in the United States. In the weeks leading up to the luncheon, its organizers received so many requests for seats that they switched the venue to one of Chicago’s largest dining rooms. Newspapers across the country covered the guest list, which included Chicago’s mayor and health commissioner; at least one member of Congress; dozens of bureaucrats, from Washington, D.C., New York, and beyond; and many of the nation’s most distinguished agricultural scientists.

The occasion for this excitement was the world’s first cold-storage banquet: a meal at which only refrigerated foods would be served. On Monday, October 23, 1911, more than four hundred guests sat down amid the drapery and gilt of the Hotel Sherman’s Louis XVI room, unfolded their white linen napkins, and enjoyed a five-course, two-hour meal in which everything but the olives in their dry Martinis had spent months in cold storage. The menu proudly listed each item’s most recent address: the salmon came from a short stay in Booth’s Cold Storage, the chicken had resided at Chicago Cold Storage since December, 1910, and the turkey and eggs had spent the past eleven and seven months, respectively, at the Monarch refrigeration plant. Addressing a reporter, Meyer Eichengreen, the vice-president of the National Poultry, Butter and Egg Association, one of the event’s sponsors, was happy to provide more detail. “Your capon received its summons to the great unknown along about last St. Valentine’s day,” he said. “And the egg in your salad—go right on and eat—well, some happy hen arose from her nest and clucked over that egg when winter was just merging into spring.”

At the time, suspicion of refrigerated foods was widespread. Stomach infections and food poisoning were a leading cause of death in America, and many blamed the mysteries of cold storage, which suspended life’s natural decay and confounded all the clues—proximity of origin, appearance—previously used to determine whether food was safe to eat. The Senate was considering legislation that would place extremely short limits on the time that meat, fish, eggs, and butter could be refrigerated. In the face of this opposition, the banquet was an industry-sponsored attempt to show that cold storage wasn’t just safe; it demonstrably improved what was being eaten. “This hotel has never served a better luncheon,” Lucien Fromente, the Sherman’s head chef, said. Harry Dowie, the Poultry, Butter and Egg Association’s national president, deemed the event proof that refrigerated foods were not just perfectly appetizing but, as he put it, “superior to those we style as fresh.” Even Congressman Martin B. Madden agreed. “I really believe, as you claim, that there is more flavor to cold-storage poultry than the kind that is advertised as freshly killed,” he said, ready to spread the word in the nation’s capital.

Today, nearly three-quarters of everything Americans consume is processed, packaged, shipped, and stored under refrigeration. In the century since Chicago’s banquet, the so-called cold chain—the shipping containers, trucks, warehouses, ripening rooms, tank farms, walk-ins, and fridges through which food moves from farm to table—has transformed what we eat, where it’s grown, the layout of our cities and homes, and the very definition of freshness. But perhaps its most remarkable imprint can still be found in how our food actually tastes, for better and for worse.

In 2010, the open‐data activist Waldo Jaquith decided to make a cheeseburger from scratch, using only agrarian methods. He and his wife had just built a home in the woods of Virginia, where they raised chickens and tended to an extensive vegetable garden. Flush with pride in his self-sufficiency, Jaquith outlined the steps required: bake buns, mince beef, make cheese, harvest lettuce, tomatoes, and onion. Then he realized that he wasn’t nearly committed enough. To really make a cheeseburger from scratch, he would also need to plant, harvest, and grind his own wheat, and raise at least two cows, one for the dairy and another to be slaughtered for the meat.

At this point, Jaquith gave up. The problem wasn’t labor but timing. His tomatoes were in season in late summer, his lettuce ready to harvest in spring and fall. According to the seasonal, pre-refrigeration calendar he was trying to follow, Jaquith would have needed to make his cheese in the springtime, after his dairy cow had given birth: her calf would be slaughtered for the rennet, and the milk intended to feed it repurposed. But the cow that provided his beef wouldn’t be killed until the autumn, when the weather started to get cold. If Jaquith turned the tomatoes into ketchup and aged his cheese in a cellar for six months, until the meat, lettuce, and wheat bun were ready, he could maybe, possibly, make a cheeseburger from scratch. But practically speaking, he concluded, “the cheeseburger couldn’t have existed until nearly a century ago.”

And, in fact, it did not. The cheeseburger is just one of many sensory pleasures made possible by a highly industrialized and refrigerated food system. More obvious ones include the delightful anticipation of pouring a crisp beer at the end of the day, the refreshing clink of ice cubes in a soft drink or a cocktail, and, of course, the joy of licking an ice-cream cone in summer. Brewers, such as Frederick Pabst and Adolphus Busch, were among the first to invest in mechanical refrigeration; without it, American-style lager beer was impossible to make year-round or at scale. David Wondrich, a historian of alcohol, has traced the cocktail back to a custom of drinking a blend of spirits, bitters, and sugar in Britain—but it wasn’t until such drinks met continual, affordable supplies of American ice, in the late nineteenth century, that the art of mixology was born. And though the ancient Chinese, Romans, and Persians all mixed snow or ice with fruit juice or dairy products to make chilled desserts, ice cream only became popular outside élite circles in the mid-eighteen-hundreds.

The opportunity to consume frosty drinks and desserts opened up an entirely new vocabulary of sensation. Some found the cold shocking at first. “Lord! How I have seen the people splutter when they’ve tasted them for the first time,” a London ice-cream vender recalled in 1851. One customer—“a young Irish fellow”—took a spoonful, stood statue still, and then “roared out, ‘Jasus! I am kilt. The coald shivers is on to me.’ ” The earliest recorded description of brain freeze seems to have been published by Patrick Brydone, a Scotsman travelling in Sicily in the seventeen-seventies. The victim was a British naval officer who took a big bite of ice cream at a formal dinner. “At first he only looked grave, and blew up his cheeks to give it more room,” Brydone wrote. “The violence of the cold soon getting the better of his patience, he began to tumble it about from side to side in his mouth, his eyes rushing out of water.” Shortly thereafter, he spat it out “with a horrid oath” and, in his outrage, had to be restrained from beating the nearest servant.

Scientists don’t yet fully understand the cause of brain freeze, but the leading theory is that the sudden, blinding pain is caused by a rush of blood to the head and the resulting pressure of brain on skull. Another mystery is why consuming chilled food and drinks is so refreshing, given that they make little actual difference for one’s body temperature. Researchers have proposed that when the temperature receptors in our mouths feel cold, they tell the brain that our thirst has been quenched. The body has other ways to monitor hydration levels—including by checking how concentrated or dilute our blood is—but, according to this theory, the cooling sensation caused by water evaporating from the tongue is an early alert that liquid has been ingested. One study found that water-deprived rats, mice, guinea pigs, and hamsters repeatedly licked a cold metal tube, instead of a hot or room-temperature one, presumably because the chill triggered an illusory sense of hydration.

Cold may also have made food and drinks sweeter—particularly in the ice‐obsessed United States. At least three of our basic taste receptors—sweet, bitter, and umami, or savory—are extremely temperature sensitive. When food or drinks cool the tongue to below fifty-nine degrees, the channels through which these receptors message the brain seem to close up, and the resulting flavor signal is extremely weak. This is why a warm Coca-Cola or a melted ice cream tastes sickly sweet: because they’re intended to be consumed cold, they need to contain too much sugar in order to boost the signal, and to register in our brains as sweet at all. (In 1929, the president of Coca-Cola set up a fountain-service training school, where his salesmen were told, “It’s gotta be cold if it’s gonna be sold.”) Washing down your food with ice water or a soft drink, as Americans often do, will have the same effect—a phenomenon that may explain why extra sugar finds its way into so many savory packaged foods, from hamburger buns to salad dressing. Everything simply has to be a little sweeter to taste right if your tongue is cold.

Refrigeration enabled the creation of American icons such as the cheeseburger and the Budweiser, but it also created an entirely new culinary category: the leftover. According to the food historian Helen Veit, the term was first coined in the early years of the twentieth century; before then, dinner scraps were fed to animals or added to a simmering stockpot. The domestic fridge changed that, inviting cooks to serve last night’s meal, often embellished to seem new. In a 1932 pamphlet titled “Cooking with Cold,” Kelvinator, a leading fridge manufacturer, promised that with “a little bit of this and a bit of that . . . the left-over foods disappear, and are replaced by delightful combinations, well blended by the Kelvinator cold.” Leaving aside its suggestion that one serve “Molded Lamb with Fruit,” Kelvinator wasn’t wrong to claim that refrigeration could make leftovers taste better. After all, chemical reactions continue in the cold, albeit slowly, and some of them improve flavor. Several years ago, Cook’s Illustrated investigated this process by serving fresh bowls of beef chili, in addition to French onion, creamy tomato, and black-bean soups, alongside portions that had been made two days earlier. Testers preferred the fridge-aged versions, describing them as “sweeter,” “more robust-tasting,” and “well-rounded.”

By way of explanation, the magazine noted that, while the soups were sitting in the fridge, the lactose in dairy had time to break down into glucose, as did some of the carbohydrates in the onion. In the chili, the meat’s protein might have separated into amino acids such as glutamate, which boosts savory notes. (Researchers have likewise suggested that the collagen in meat, which is first released during cooking and then sets to a jelly in the fridge, melts to create a silky texture when a stew, lasagna, or chili is reheated.) Curries fare well in the fridge because the flavor molecules in many spices are soluble in fat; the more time they have to disperse, the more evenly they’ll be distributed. And water in a dish tends to soak into starch over time, so that the black beans in a refrigerated soup have more time to absorb the rich umami notes in the broth.

Not all the tastes of refrigeration are as welcome. The Chicago banquet of 1911 was followed by some disapproving editorials, including one, from the Chicago Inter Ocean, that bitterly predicted the triumph of cold. “There seems to be only one consolation,” the paper concluded: the Americans who remembered what food tasted like before refrigeration would eventually die off, while “the generation growing up doesn’t know the difference and may be happy in its ignorance.”

This prediction has come true. Few of us can taste the difference between wet-aged and dry-aged beef; even fewer can distinguish the tastes of different pastures and seasons in milk fresh from a cow. In the United States, especially, where convenience and value are often prioritized over taste, stiff, acidic supermarket peaches and starchy, cardboard-flavored peas are accepted, if not relished. But even the least picky among us can admit that one fruit in particular is a shadow of its freshly harvested self: the tomato.

“Hard,” “plastic,” “watery,” “repulsive”—the scientist Harry Klee has heard all the descriptions of the supermarket tomato, and he agrees. “They have no flavor at all,” he said. “They’re awful.” When I first spoke to Klee, a few years ago, we had both just come in from tending our own back-yard tomato plants. “I only grow my own varieties,” he told me. This made sense: Klee has spent much of his career trying to design a tomato that can survive the cold chain and still emerge with some flavor.

Klee entered the field of horticulture in the nineteen-seventies, when gene-modifying technology was still new. At the time, most plant scientists thought the reason American tomatoes taste bland is that growers in Florida—where up to half of the country’s fresh tomatoes are produced—pick them when they’re hard and green, before they’ve developed the potential for flavor. Later, when the fruit is ready to be sold, it’s gassed with ethylene to force it to ripen. This method has made it possible to ship an otherwise squishy fruit all over the country without enormous losses. Klee, who spent the eighties working for Monsanto, wondered whether it might be possible to use genetic engineering to slow the ripening process, so that the fruit would stay green on the vine for longer, accumulating the nutrients that become the building blocks of flavor. “You’d have a bigger window to let them ripen on the plant and still ship them without losing them,” Klee explained. “It would be a win-win for everybody.”

Klee wasn’t the only one trying to create a tomato that could endure the rigors of refrigerated shipping. Around the same time, scientists at Calgene tweaked a gene that regulates pectin metabolism, hoping to delay the softening process in ripe tomatoes. In 1994, their efforts resulted in the Flavr Savr tomato—the first genetically modified crop sold in the U.S.—but the variety had low yields, and the fruit was still slightly too squishy to survive industrial handling. The bigger issue, Klee realized, was that he and the Calgene scientists were focussed on ripening, though commercial tomato varieties had almost no flavor even when they were allowed to redden on the vine.

“The commercial tomatoes have been selected for being very hard, for having great shippability, great shelf life,” Klee said. “They don’t have the genetic capacity to have great flavor.” In the nineties, Klee moved from Monsanto to the University of Florida, where he began trying to decipher the chemistry of tomato flavor. To understand which molecules mattered, he and his colleagues grew hundreds of tomato varieties and measured exactly how much of some seven hundred different chemicals—acids, sugars, and an array of volatile organic compounds—they contained. Then he took more than a hundred and fifty tomatoes, representing the widest variation in flavor chemistry, and gave them to consumer panels to find out which ones tasted the best.

The process took years, but, by inspecting the molecular makeup of the tomatoes that scored highest in the tests, Klee was able to narrow in on the twenty-five volatile compounds, plus some sugars and acids, that make up the recipe for the Platonic tomato—or tomatoes. “There are multiple answers to ‘What’s the perfect tomato?’,” Klee told me. He’s found that, in general, younger people respond to the sugar content, while older consumers and women like their tomatoes more complex, with a greater array of volatiles. Curiously, the most loved flavor chemicals are all derived from vital nutrients, including essential fatty acids, amino acids, and antioxidants—suggesting that the tastiest tomatoes may also be the healthiest.

Since 2018, Klee has been working on breeding a tomato that combines the seven most important flavor genes with the same yield, disease resistance, and ability to be shipped under refrigeration as a commercial variety. “It’s like putting a jigsaw puzzle together,” he said. Using only traditional breeding techniques, he crosses a modern commercial tomato with varieties possessing good-flavor genes, then checks to see whether their progeny end up with the best of both parents. “Then we repeat the process again and again and again,” he said.

When we spoke, more than three decades after he had begun working on the case of the tasteless tomato, Klee told me that he and his team had cracked it. “Just last week, we got to the point where we had something that had all seven of the genes we wanted in,” he said. The consumer panels loved the flavor, and the yield was great, but Klee worried that the tomato was still a little too small for growers to embrace, because picking more fruit per pound increased labor costs. “I think we’re going to have to back-cross it a little more,” he said. “The problem is that sugar is a direct trade-off with fruit size—the bigger the fruit, the less sugar it has, and vice versa.” (This is true for fruit in general. Many shoppers choose the largest apples or strawberries, under the assumption that they provide better value, but they are, almost without fail, significantly less delicious than smaller ones.)

Klee, who is now semi-retired, told me that his quest is far from over. Spending more than four days below fifty-five degrees Fahrenheit alters a tomato’s DNA in such a way that the fruit’s ability to make volatile flavor chemicals shuts down completely. “It doesn’t affect the sugars and the acids, only the volatiles,” Klee said. “But the tomatoes taste worse, no question.” Tomato packers and trucking companies can keep the tomatoes at fifty-five degrees or above, but home fridges are typically set at forty degrees, and supermarkets that have only one cold room will set it at thirty-four degrees, to protect meat and dairy. “Ten years from now, we could probably understand the genetics of that response and figure out how to prevent it,” Klee said. “It’s probably beyond the scope of my career.”

Klee’s approach—reëngineering the tomato to taste good in our refrigerated food system, as opposed to redesigning the supply chain to accommodate the tomato—is expensive and time-consuming, but the results are promising. His process offers a road map to breeders working on fruits like mangoes and strawberries, whose flavor has been similarly diminished in favor of cold-hardiness. Still, his tomatoes suggest the same logic as industrial orange juice: adopt a standard, consumer-optimized taste profile that salvages flavor from the wreckage of refrigeration. They offer a solution to a problem that need not exist. We could just limit our tomato consumption to the summer months, when local specimens, in all their tangy deliciousness, are available.

“The reality is, most people do not want to eat like Alice Waters,” Klee said, referring to the Berkeley chef known for her commitment to serving only local, seasonal produce. “No matter how bad the quality, people are still going to want to buy a tomato in January, and without refrigeration and postharvest handling that’s impossible.”

Although I remain firmly in the Alice Waters camp, I wanted to taste the tomato of the future. Klee sent me a packet of seeds, and I carefully sowed his cherry, plum, and globe tomatoes alongside some of my favorite noncommercial varieties. Within days, they burst out of the potting mix, sending out shoots that perfumed the air with their green, spicy scent. In a few months, I was rewarded with a profusion of fruit. They looked like supermarket tomatoes—bright-red spheres alongside my striped, bulbous, purple-and-yellow heirlooms—but they were so juicy, tart, and savory that they never even made it into my fridge. ♦

This is drawn from “Frostbite: How Refrigeration Changed Our Food, Our Planet, and Ourselves.”


No votes yet.
Please wait...

Leave a Reply

Your email address will not be published. Required fields are marked *