The Existential Crisis of a Starbucks Latte

Starbucks foam and the rise of ambiguous materials

Ten years ago if you’d ordered a coffee almost anywhere in Britain, you would have found yourself looking down at a circle of watery brown liquid with a smattering of bubbles scattered over the surface. It looked as though someone had added a dash of detergent to dishwater and then blown into it absentmindedly through a straw. The advent of coffee chains, domestic and international, has entirely transformed the coffee-drinking experience into a saturated, multilayered event. And the spiritual home of luxurious superfoam is Starbucks, where the voluminous, airy froth tops your coffee plump and proud as a teddy boy’s quiff.

In fact, it’s hard to believe this stuff was ever as simple as milk. Only the faintly sour smell reassures you that it probably came out of a cow at some point in its history. At my Starbucks the baristas have nicknamed the process that transforms it “rock and roll,” derived from the action of knocking the stainless-steel jug against the counter to dislodge air bubbles as the hot steam is pumped through the milk. Today the overengineered machinery of coffee-making is a contemporary fetish, the baroque complexities of the stainless-steel pipework and pressure gauges suggesting the mechanical thrust of a classic car plumbed into the artistry of a church organ.

The science of foaming involves, among other things, the speed, temperature, and humidity of the steam; the nature of the nozzle; the shape of the jug; the fat content of the milk, and how the steam is introduced. Complex fluid dynamics combined with the physical properties of milk result in a precise quality of foam. The end product is mechanically worked-over milk, battered into assuming an entirely different quality. Generic natural milk becomes iden­tifiable with a particular place, experience, and brand—a product rather than an ingredient—and also serves to justify the markup.


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With a limited product range involved, intense competition magnifies the importance of each element: bean, roast, grind, and blend become significant points of difference between brands. This is the force that has driven steamed milk into such elaborate form. The significance of Starbucks foam is the embedding of brand identity into a natural phenomenon: lactate becomes logo.

And along with the thick, warm, smooth, milky coffee that I’m slurping through my oversize beaker, I’m sucking up something else. Among all those soothing sensations there is a vaguely unsettling feeling, located intangibly between taste and texture. It’s as though my Grande Latte is haunted by other materials that aren’t quite present. The milk is hallucinating unmilky attributes: a springy spawn with an easy, oily slickness, a sweetness on the verge of vanishing within a numb plasticized volume. How did it get like this? What made it so ubiquitous so quickly?

Steaming alters milk on a molecular level, breaking the chemical bonds within it and sweetening the taste by increasing the solubility of lactose. It also increases the surface area of the liquid, heightening the sensation of taste. Water and milk fat form an emulsion that strengthens the bubble skin. Foaming is now a staple technique in the avant-garde kitchens of molecular gastronomy, a culinary movement that sees cooking recast as thermo-chemistry, where kitchen becomes laboratory and chef turns scientist. Michelin triple-star chef Heston Blumenthal uses the effect at his restaurant, the Fat Duck, in Bray, Berkshire, United Kingdom, to heighten taste. His green-tea sour mousse is sprayed as foam from a canister into a spoon and then dropped into a bowl of liquid nitrogen to freeze the foam in­stantly into a glob of high-tech palate cleanser.

He is not the only chef to come up with new ways of presenting flavors and texture. Ferran Adrià, head chef of El Bulli restaurant, on the Costa Brava in Spain, has pioneered the concept of vegetable foams. He extrudes a mixture consisting of natural flavors mixed with a gelling agent such as agar—derived from the cell walls of some species of red algae or seaweed—through a whipped-cream maker equipped with nitrous-oxide cartridges. Out of this come delicacies such as foamed espresso, foamed mushroom, and even foamed beetroot.

In these haute-cuisine scenarios, foaming is a way of capturing taste like a perfumer captures scent. Both disciplines trap an essence, then suspend it within a delivery mechanism that frames and artic­ulates a precise experience. The chef and perfumer take elements of nature, then filter them through culture. They refine primal animal responses of taste and scent into highly crafted artifices. In these intricately foamed dishes, flavor takes precedence over the substance in which it is suspended. Taste becomes divorced from its biological origin and amplified—a process that threatens to wring every drop of pleasure from nature.

Foaming is substance made less physical. The act introduces emptiness into the heart of a solid. There are gaps where there shouldn’t be, like nights you can’t remember because of binge blackouts, or holes in the fabric of life—bereavement or heartbreak. A solid that is, in the words of the Buzzcocks’ Pete Shelley, “Hollow inside, we’re all hollow inside / But I couldn’t find out what the reason was / Why I was / Hollow inside.” This is the existential echo that pervades my Starbucks latte.

Foaming is used to alter a wide variety of materials. Rubber, polystyrene, concrete, aluminum, and glass can all be foamed or aerated to extend the original material’s qualities, delivering lighter, stronger, and more flexible substances with greater insulating properties. In cosmetics or construction, edifice or edible—you’ll find them all around you, even if you don’t see them. They’re present in the spongy feeling when you walk in your high-tech running shoes, the building envelope that insulates your home or office, the designed collapse of your car’s bumper in midcrash.

During the making of these substances, foam is cre­ated by inducing materials into a state of ex­cite­ment. Once the foam has solidified, the material’s architecture has changed from solid to cellular. It is a frozen ephemeral state, where matter is held just on the right side of instability and collapse. The foaming process adds complexity to materials. They become more ambiguous in their structure and behavior. And this ambiguity has a deeper undertone, suggesting that certainties can become unbound, that categories leak and bleed. Materials once gave grounding to the physical boundaries of human experience, but these borders are becoming blurred, hazy, untrustworthy.

“Particular foods were once considered as a single entity: an apple was an apple, a cabbage a cabbage, and a pork chop a pork chop,” Blumenthal writes. “Now, though, we know that an apple is, in fact, a recipe in itself, consisting of tens of thousands, even hundreds of thousands, of molecules, each contributing something to the texture, flavor, or taste.” Unraveling nature is one thing. Repackaging it is quite another. When you put it back together, it turns into something very different.

Blumenthal’s point echoes through modern design: traditionally designers regarded materials as a kind of “found” truth that we inherited from nature—and thus both fundamental and essential. Stone, for example, was characterized as the immov­able foundation or tablet of moral truth. This attach­ment of meaning to physical stuff is central to design culture. Maybe the old Modernists were right—there is a morality to materials. Modernism found its medium in concrete, glass, and steel. These materials reflected the circumstances of newly industrialized societies. They were used to express the idea that industrial production could create an idealized society. At the same time, they were a brutal snub to the stone used in bourgeois Beaux- Arts architecture, which attempted to connect to a set of classical ideals. Of course, we now regard both classical and Modernist ideals with distrust. We don’t believe in the autocratic or aristocratic structuring of society, and we carry a grow­ing ambivalence toward industrialization’s social and environmental consequences. Perhaps the rise of foamed, ambiguous materials expresses that gnawing ambivalence.

Foam is a strangely liberated state: ephemeral, light-headed, almost intoxicated. It’s stuff that has been agitated into an unnatural state that has escaped the confines of ordinary substance. In the spongy, stretchy, warm, superstrong foam we feel the sickening trembling thrill of our time. This is the hyped-up sensation that both comforts and disgusts in equal measure as I slurp down my Grande Latte.

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