At Ivan Day’s house, we watched as a batch of citrus- and bergamot-scented water ice turned from a translucent yellow liquid to a snowy white cream. The temptation to taste some was immense, poisonous or not. Day remarked that he and Robin Weir have spoken of relaunching the Mrs. Marshall machine in modern nontoxic materials. They should. It is better than anything now on the market: quicker, more efficient, more aesthetically pleasing, and entirely carbon-neutral to operate. For someone in possession of a Marshall’s Patent Freezer, it was probably easier and quicker to make homemade ice cream in 1885 than it is in most kitchens now. Even the revolutionary new Pacojet, which claims to make frozen desserts in twenty seconds by “precision spinning,” is actually slower than the Marshall freezer: when “pacotizing,” you need to freeze ingredients for at least twenty-four hours before you start. What’s still more
noteworthy about Mrs. Marshall’s innovation is that ice-cream making is not some neglected art (jelly molds were better on average a hundred years ago than they are today, but that’s because most of us aren’t that interested any more in building jellies to look like palaces). Many cooks now would love to be able to do what Mrs. Marshall managed. The range of ice-cream flavors in her
Book of Ices
speaks of the freedom she had to invent anything she liked, in the knowledge that once the mix was made, the finished ice could be ready in minutes: she has recipes not just for vanilla, strawberry, and chocolate but also for burnt almond, gooseberry, greengage, cinnamon, apricot, pistachio, quince, orange flower water, tea, tangerine.
Mrs. Marshall thought up another astonishing ice-cream idea. In an article in her magazine,
The Table,
from 1901, she suggested an amusing trick for “persons scientifically inclined”:
By the aid of liquid oxygen . . . each guest at a dinner party may make his or her own ice cream at the table by simply stirring with a spoon the ingredients of ice cream to which a few drops of liquid air has been added by the servant.
She probably got the idea from seeing a scientific lecture on liquefied gases at the Royal Institution. It is not clear if she ever actually tried it herself. The scientist Peter Barham—who makes ice cream using liquid nitrogen—suggests not, because “a few drops” of liquid oxygen would probably not be enough to freeze a whole bowl of ice cream.
Nevertheless it is striking that, with the twentieth century just dawning, this great culinary innovator had devised a method of making ice cream that would still seem high-tech over a hundred years later. Diners at Heston Blumenthal’s The Fat Duck, probably the most cutting-edge restaurant in England, still gasp when they see desserts frozen at the table with liquid nitrogen.
Mrs. Marshall’s liquid air came at the end of hundreds of years of ice-cream innovation. The basic device of adding salt to ice to
lower its temperature was discovered around 300 AD in India. It works because salt lowers the freezing point of ice—in theory as low as–5.8°F. By the thirteenth century, Arab physicians were making artificial snow and ice by adding saltpeter to water, preempting Bacon by more than three centuries. Visitors from Europe to the East were struck by the wonderful sherbets and chilled syrups. Pierre Belon was a Frenchman who visited the Middle East in the sixteenth century. He marveled at the sweet cold drinks:
Some are made of figs, others of plums, and of pears and peaches, others again of apricots and grapes, yet others of honey, and the sherbert-maker mixes snow or ice with them, to cool them.
In Persia, sherbets were made from lemon, orange, or pomegranate juice. First, the fruit was squeezed through a silver strainer. Sugar was added, and water to dilute. Finally, ice was piled in. Like the icy gola drinks still made on the beaches of India, this was somewhere between lemonade and a slush puppy: a cooling balm on a sweltering afternoon. “Give me a sun, I care not how hot,” wrote the poet Byron when he visited Istanbul in 1813, “and sherbet, I care not how cool, and my Heaven is as easily made as your Persian’s.”
By the seventeenth century, Europeans were making their own frozen water ices in Paris, Florence, and Naples, and by the mid-eighteenth century, sweet ices were a well-established food.
Sorbetto
sellers walked the streets of Naples (
sorbetto
rather than
gelato
was the all-purpose Italian term for ice cream at this time, and did not signify a lack of cream), offering ice cream for sale with flavors including sweet orange, bitter cherry, jasmine, and muscat pear. It was dolloped out of the
sorbettiera
in which it was made. This was a tall, cylindrical metal container with a lid set in a bucket of ice and salt. To break up the ice crystals and keep the
sorbetto
creamy as it froze, the sellers spun the
sorbettiera
around on the ice-salt mixture every few minutes, an action that churned the mixture inside. Once in a while, the ice would be stirred with a wooden spatula. This is
another low-tech way of making ice cream that can produce results every bit as good as our giant electric machines.
In short, we have very little to teach our ancestors when it comes to domestic ice-cream making. Our main nonelectric method for making sorbet—freezing it in a plastic container in the freezer, whisking every so often to break down the ice crystals—is hopelessly inferior to either a
sorbettiera
or a Marshall’s Patent Freezer. No matter how often you take it out and whisk, the end result is always an unappealing slab of ice. Aside from industrial ice-cream manufacture—which in most cases is the art of cheapening the product with air and additives—there have been few real innovations since Mrs. Marshall’s day.
Given the Victorian mastery of ice-cream technology, it might be expected that refrigeration was the obvious next step. Certainly, in the grandest houses of Europe, where the kitchen servants were divided up into savory cooks and sweet confectioners, the confectioners sometimes had access to a “cold room” where pastry could be kept cool, ices made, and meat stored. In more modest houses, however, refrigeration was still in its infancy, long after the Industrial Revolution. In the 1880s, Mrs. Marshall sold a range of “Cabinet Refrigerators” with “all modern improvements.” These were nothing more than freestanding wooden kitchen cabinets with a couple of containers for ice in the top. Whereas Marshall’s Patent Freezer is one of the great neglected kitchen technologies, her fridges were nothing but Victorian curios. They have been rendered entirely obsolete by the electric compressor fridge that now shapes all our lives.
A
few years ago, I was talking to an American in London who was feeling homesick. The thing that really got her, she said, was that her British kitchen, with its poky little appliances, was too quiet. She missed the hum—not loud, but constant—that comes with a big American fridge. For her, this hum was the sound of home.
It was not inevitable that twentieth-century American fridges would develop this friendly hum, which is a consequence of the
motor inside electric refrigerators (large fridge = large motor = loud hum). There was another technology available that was potentially no worse than the electric fridge: the gas absorption fridge, whose operation was silent. Both methods of refrigeration—compression and absorption—were developed in the nineteenth century. All refrigeration is based on the thermodynamic properties of liquids and gases. It is not about adding “cold”—there is no such substance—but about pumping heat away. Refrigeration exploits the fact that when liquids turn into gases, heat is transferred away, like the steam rising from a bowl of soup as it cools down.
Since ancient times in Egypt, the principle of evaporation had been used to chill water: liquids were stored in porous earthenware jars, well wetted on the outside. As the surface water evaporated, it transferred heat away from the water inside the jar. In India, this technique was actually used to make ice. Trenches were dug and covered with straw. Shallow earthenware pans were put inside, filled with water. Under the right climatic conditions—calm and not too windy—the water turned to ice.
From the eighteenth century on, a series of inventors experimented with ways to speed up the chilling effects of evaporation. In the early nineteenth century, Richard Trevithick, a Cornish engineer, succeeded in building the first machines in which expanding air under pressure converted water to ice.
Air, however, was not a great refrigerant—it is a poor conductor of heat, which is after all the aim of the game. Engineers started to try different refrigerant gases. In 1862, the Harrison-Siebe vapor compression ice maker was launched, using ether instead of air. It was a vast and intimidating machine, “driven by a steam engine of fifteen horse powers.” It worked on the same basic principle of the fridges in most of our kitchens. A gas—in this case, ether—is compressed through metal coils into a liquid state. It is then allowed to expand again into a gas, which causes heat to be removed—this is the refrigerant effect. Finally, the gas is re-liquefied, and the whole process starts again. The Harrison-Siebe machine worked very well,
once early tendencies to explosions were resolved. The great steam-powered ice factories of the 1890s used the compression technique to churn out hundreds of tons of clean, diamond-bright ice a day.
This was not the only way to manufacture ice, however. French inventors, notably Ferdinand Carré, had come up with an alternative method: gas absorption. The difference is that instead of forcing the gas through compressor coils, it is dissolved in a “sympathetic” liquid. In Carré’s version, the liquid is water and the refrigerant is ammonia. It is a more complex process than compression: instead of one substance to consider, there are two. Nevertheless, Carré’s machine was impressive. It worked on a continuous cycle and in 1867 could produce as much as 200 kg of ice per hour. In America, in the Southern states, which had never had a dependable supply of natural ice, factories sprang up equipped with vast Carré absorption machines. By 1889, there were 165 plants in the South, manufacturing beautiful, clear, artificial ice, with which to chill mint juleps or aid the transport of fragile Georgia peaches.
Yet while the commercial ice industry had become mechanized, the ordinary American housewife still struggled on with her icebox. As late as 1921, a writer for
House Beautiful
was complaining of the drudgery of maintaining this cold receptacle:
Somebody has had to wipe up the wet spot where the ice man set the cake while he was waiting . . . Somebody has had to pull out the pan each day from underneath and empty out the water . . . Somebody has had to keep smelling around the ice-box, day by day, to see when it began to get foul and needed scouring.
All of this daily tedium was dispensed with upon the arrival of domestic fridges, both gas and electric, which happened in the interwar years. It has been said that the decade between the end of World War I and the start of the Depression saw the most “dramatic changes” in the patterns of household work in America of any decade
in history. In 1917, only 25 percent of households in the United States were on the electric grid. By 1930, that number was 80 percent. A critical mass of consumers with access to electricity was a crucial factor in the spread of the electric compressor refrigerator. This was a high-stakes business: unlike an electric iron or an electric kettle, an electric refrigerator is never switched off; for twenty-four hours a day, every day, it uses power, humming away. The electric companies therefore had a strong interest in encouraging the spread of electric refrigeration in the home.
The first household names in refrigerators were Kelvinator and Frigidaire, both firms founded in 1916 and both electric. There were teething troubles, to put it mildly. If you bought an electric refrigerator in the 1910s, you did not get an entire self-contained unit. The fridge company came and installed a refrigerating mechanism in your existing wooden icebox, which often could not take the strain, warping and yanking apart as the motor rattled away. The machinery, moreover, was so huge, it might leave scant room in the icebox for food. To get around this, the compressor and the motor were sometimes installed in the basement, with the refrigerant laboriously pumped back upstairs to the icebox. The compressors frequently malfunctioned, and motors broke. More worrying was the fact that the early refrigerant gases used—methyl chloride and sulfur dioxide—were potentially lethal. Given that the units were very badly insulated, this was a serious risk. In 1925, the scientist Albert Einstein decided to design a new, better refrigerator, after he read a newspaper story about an entire family killed by the poisonous gases leaking from the pump of their fridge. The Einstein refrigerator—developed with his former student Leo Szilard and patented in November 1930—was based on the principle of absorption, like the Carre machines. It had no moving parts and needed only a small heat source such as a gas burner to make it work.
The Einstein fridge was never marketed because it was overtaken by events. In 1930, the industry introduced a new nontoxic refrigerant
called Freon-12. Almost immediately, all new domestic fridges adopted Freon. It seemed a new dawn—though half a century later, refrigerator manufacturers would be frantically looking for alternatives to Freon, because it is one of the main chlorofluorocarbons implicated in the depletion of the ozone layer.
Also in 1930, US sales of mechanized fridges overtook sales of iceboxes for the first time. By then, fridge design had moved far beyond those old leaky wooden chests. The early self-contained fridges of the 1920s tended to be white, with four legs like a dresser. The most famous was perhaps the General Electric “Monitor Top” refrigerator, a white box on legs with the refrigerating mechanism in a cylinder protruding on top. By the 1930s, fridges grew in stature and lost the legs, developing a streamlined metallic beauty.
In 1926, Electrolux-Servel devised a continuous absorption gas-powered fridge, and for a while it looked as if gas fridges might be preferred to electric ones. The basic invention came from two Swedish engineers, Carl Munters and Baltzar von Platen. These new gas fridges needed no motor to run, were cheaper, and ran silently. A Servel ad from the 1940s showed a well-dressed white couple boasting that they had managed to retain the services of their black maid after they bought an Electrolux: “Mandy’s giving us another chance since we changed to silence.” Mandy comments: “Lordy, it sure is
quiet!”
Despite the advantage of silence, Servel never had the same clout as the big electric companies like General Electric and now, the idea of a gas fridge sounds quaint. But the competition between the two models—silent gas versus humming electricity—drove innovation on both sides, which is partly why American fridges became so good, so quickly. Fridges of the late 1930s already had plenty of modern accoutrements: push-pull latches on the door; adjustable split shelving; hydrating compartments for vegetables and salads—all things that fridges today still sell themselves on.