Cooked: A Natural History of Transformation

by Michael Pollan

  By breaking down lactic acid and producing ammonia, Geotrichum neutralizes the pH of the rind, changing the environment in such a way as to make it hospitable to subsequent waves of bacteria and fungi. By sending its filamentous hyphae down into the paste, the fungus in effect “tills” the rind of the cheese, digging microscopic channels that allow other aerobic microbes, like Penicillium, to move deeper into the cheese, contributing new flavors and aromas. These penetrations gradually thicken the rind and multiply its population of microbes, both in number and in kind. Soon the rind accumulates a grayish dust of “fungal debris”—spores and the bodies of dead fungi—that gives off the musty odor of a dank, neglected cellar. By day thirteen pinkish patches of Trichothecium roseum have begun to powder the rind, giving a violet cast to the Saint-Nectaire. By now the pH of the rind has been neutralized, creating a happy habitat for coryneform bacteria such as Brevibacterium, which eventually will contribute powerful aromas to the ripening cheese.

  And so it goes for the two months it takes a Saint-Nectaire to ripen, each species altering the rind environs in such a way as to pave the way for the next, in a predictable ecological succession that Sister Noëlla carefully documented in her dissertation. Along the way, each species releases its own set of enzymes, each one a customized molecular tool for breaking down a specific fat or sugar or protein into an amino acid or peptide or ester that contributes a specific flavor or aroma to the ripening cheese. Within a few weeks, the process of ecological succession has culminated in the establishment of a fairly stable community of fungi and bacteria. Much about this microbial community remains a wilderness to science. But Sister Noëlla is in touch with a group of microbiologists who are actively exploring the cheese-rind ecosystem, hoping to learn how the various species compete and cooperate, and how they may communicate with one another to defend their turf (and in turn the cheese beneath it) from invasion, in a process known as “quorum sensing.”

  Listening to Sister Noëlla exalt this leprous skin of decomposed milk as a vibrant ecological community is to appreciate just what a weird and wonderful achievement cheese is: how our ancestors figured out how to guide the decomposition of milk so that it might be arrested and then defended, using a jujitsu move that deftly deploys rot against rot, fungus against fungus, to suspend milk’s inexorable slide into putrefaction just long enough for us to enjoy a tasty cheese. Other ferments operate on the same general principle, earth to earth deferred, but, unlike wine or beer or a pickled beet, the aroma of a ripened cheese won’t ever let us forget the role rot has played in its creation.

  Over time, the fungi living and dying in a cheese rind work to neutralize their environment, a development that hastens the ripening of the cheese in two important ways. First, the difference in pH between the paste and the rind creates a “gradient,” or imbalance, that serves to draw the strong-smelling compounds produced on the rind deep into the paste; ripening from the outside in, the cheese is bland no longer. At the same time, the rising pH of the rind creates conditions much to the liking of a notorious microbe called Brevibacterium linens, the appearance of which, beginning around week three, is marked by a distinct reddish-orange cast creeping over the rind. But you don’t need to see B. linens to know it has arrived: B. linens is the bacterium responsible for much of the stink in a stinky cheese. Along with a few other members of its bacterial family, the coryneforms, B. linens is the reason certain ripe cheeses need a room of their own.

  Saint-Nectaire is home to a healthy population of B. linens that, when the cheese is fully ripe, gives it its distinctive barnyard smell. But it is in the washed-rind cheeses—Époisse, Limburger, Taleggio, and, in America, newer ones like Red Hawk or Winnimere—where B. linens is actively encouraged to flourish, imbuing these cheeses with their powerful and occasionally room-clearing aromas. Washing the rind, usually with salty water (sometimes with wine or beer), creates an environment maximally hospitable to B. linens, which in turn can single-handedly create an environment that is either much more or much less hospitable to members of our species. Some people love the smell of B. linens, or learn to; others find it revolting. And still others are repelled and attracted to it at the same time, captivated by what might be called the erotics of disgust.

  “Oh, I really like that term,” Sister Noëlla said, when I raised, as delicately as I could, the issue of rankness in her cheese. The subject of disgust is not something I’ve found many cheese makers eager to discuss, at least not in the company of journalists. But Sister Noëlla is happy to talk about the earthier dimension of her work, at least up to a point.

  “Cheese is all about the dark side of life,” she said one afternoon as we were strolling up the hill to her lab. She told me about a French cheese maker of her acquaintance, a monk by the name of Frère Nathanaël, who makes a strong cheese called Tamié at his monastery in the Haute-Savoie. She once asked him how he determined when a Tamié is ripe. You turn it over and sniff the bottom, Frère Nathaniaël told her. “Ça sent la vache.” It’s ready when it smells like the cow. And then, in case that wasn’t quite clear enough, he added, “The back end of the cow!”

  It suddenly dawned on me that “barnyardy”—a term cheese mongers use in praise of certain stinky cheeses—is a euphemism for manure. (Duh!) Certainly the manure of some farm animals, such as cows, is not unappealing, at least when they’ve been out grazing on pasture. Yet some cheeses make even less socially acceptable allusions, if that’s the right word. The various aromas of washed-rind cheeses are often likened to those of the human body in its various parts. A French poet famously referred to the aroma of certain cheeses as the “pieds de Dieu”—the feet of god. Just to be clear: foot odor of a particularly exalted quality, but still—foot odor.

  Sister Noëlla told me about another cheese-maker friend of hers, James Stillwaggon, an American living in France, who holds unusually frank views on the subject of cheese olfaction. She had recently quoted him at the end of the draft of an article on the microbiology of cheese rinds, though she wasn’t sure if his remarks would survive editing. The quote came from an exchange the two had had on the question of why the vocabulary used to describe wine is so much richer and more nuanced than the vocabulary used to describe cheese. Wine talk is full of vivid metaphor—comparing wines to specific fruits and flowers, for example—whereas, as Stillwaggon pointed out, the flavors of cheese usually elicit only vague, generalized comments “like ‘Mmmm, good!’ ‘Interesting!’ ‘Fantastic!’

  “If we address frankly what is evoked by cheese, I think it becomes clear why so little is said. So what does cheese evoke? Damp dark cellars, molds, mildews and mushrooms galore, dirty laundry and high school locker rooms, digestive processes and visceral fermentations, he-goats which do not remind of Chanel … In sum, cheese reminds of dubious, even unsavory places, both in nature and in our own organisms. And yet we love it.”

  In its very suggestiveness, cheese is both like and unlike many of the other foods humans cook or ferment. Whether by fire or water or the action of microbes, one of the ways humans transform the edible stuff of nature is in the direction of greater allusiveness—in taste or smell or appearance. Just as we take pleasure in enriching our language with layers of metaphor and allusion, we apparently like to trope what we eat and drink, too, extracting from it not only more nourishment but more meaning as well—more psychic nourishment, if you will. It just so happens that the more vivid, odiferous tropes that cheese makers have teased out of milk can verge on the indecent, taking us places polite society doesn’t like to go.

  But the question arises: Why would we want to go there in the first place? Why don’t cheese makers stop with the sweet, freshly showered scent of mozzarella,
rather than press on to the ripe raw-milk Camembert with its suggestions of, well, negligent hygiene?

  Compared with some other mammals, we humans have long been alienated from our sense of smell. From the moment we began to walk upright, the eye took precedence over the nose. This, at least, is Sigmund Freud’s theory for why humans have repressed so much of the sensory data supplied by the nose, and why our vocabulary for describing smells is comparatively so thin and generalized. (Mmmm, good!) The smells we are repressing are of course those of the lower body and the earth, which walking upright allows us to transcend, or at least overlook, in humanity’s age-old top-priority project of putting space between itself and all the other animals. But that project has a cost. The reason those smells so transfix mammals that still walk on four legs is that they contain deeply compelling information, information the high-minded biped is missing. Freud never said this, but Stillwaggon conceivably might: A strong cheese puts us back on all fours.

  Metaphorically speaking, of course. Or maybe not. Because one of the most curious things I learned about the bacteria that give cheese their aromas is that they are, at least in some cases, closely related to the bacteria that give us our aromas. Brevibacterium? It not only lives in the salty damp of a washed-rind cheese, but is equally at home in the salty damp under human arms or between human toes. (I give you “the feet of god.”) Sweat by itself has no discernible odor; what you think you smell when you smell sweat are the metabolic by-products of brevibacteria, as they busily go about fermenting, well, you. And your toes and armpits are not the only bodily zones where such fermentations are taking place, either.* So it may well be that the allusiveness of a funky cheese to the human body is actually more literal than metaphoric, a matter not so much this stands for that as this is that, too, in food form. What’s going on in certain cheeses doesn’t just remind us of the body; in some sense it is the body, or at least the fermentations unfolding thereon and -in.

  As you might expect, the French are much more comfortable with these ideas, and these cheeses, than Americans seem to be. In fact, some Frenchmen regard America’s uneasiness with raw-milk cheeses (which tend to be more odiferous than cheeses made from pasteurized milk) as further proof of our puritanism in carnal matters. Pierre Boisard, a French sociologist, celebrates a raw-milk Camembert as “a living substance produced by an animal organism, [that] constantly reminds us of the body, of sensual pleasure, of sexual fulfillment, and of all that is forbidden in it.” Only “hidden Puritanism re-entering through the backdoor [of] alimentary hygiene”—and not the threat from listeria, say, or salmonella—could possibly explain the American government’s ban on raw-milk Camembert.*

  No, I never did float this theory to Sister Noëlla. Didn’t get the chance. … Okay, actually I could never figure out quite how to broach it. How do you ask a nun whether she believes the government’s crackdown on raw-milk cheese is rooted in sexual repression?

  Though I did ask her, before leaving the abbey, if she could put me in touch with her friend Jim Stillwaggon, or refer me to any of his writings. She had described him as a philosopher as well as a cheese maker. Had he published any of his reflections on sex and death in cheese? Did he have a Web site, perhaps?

  “No, and it’s probably just as well. I’m just not sure the world is ready for Jim.”

  On my drive home, a fragrant chunk of Sister’s Noëlla’s ripe Saint-Nectaire warming on the seat beside me, I wondered if the French might be right, and if the disgust we sometimes register at the smell of a strong cheese is the product of sexual repression—a taboo at work. It does seem to be the case that the smells of cheese are ripe with the smells of the body, human or animal. Yet not all of those smells are necessarily sexual in nature. When we consider “the body,” certainly there is sex to consider, but isn’t there also death? I also wondered if maybe, on the theory (contra Freud) that sometimes a cigar is just a cigar, disgust is sometimes just disgust.

  When I got home I began to dig around in the literature of disgust, which in the last several decades has attracted a handful of interesting thinkers from a wide range of disciplines, including psychology (Paul Rozin), philosophy (Aurel Kolnai), even law (William Ian Miller). Disgust, I learned, is one of the primary human emotions; it appears on even the shortest list of human emotions, and in fact is unique to our species. (Though you do have to wonder, how can we be so sure?) Darwin, who wrote about disgust in his 1872 book, The Expression of the Emotions in Man and Animals, described it as a reaction to something that offends our sense of taste (the word comes from the Middle French desgouster, or “distaste”), rooted in the biological imperative to reject foods that might be dangerous.

  Building on Darwin, Paul Rozin writes that the emotion of disgust originates in “the revulsion at the prospect of oral incorporation of an offensive object.” Disgust is thus a crucial tool for an omnivore at constant risk of ingesting toxic substances. But the emotion of disgust has since been co-opted by other, higher human faculties, such as morality, so that we are disgusted by certain kinds of morally offensive behavior. Rozin writes, “A mechanism for avoiding harm to the body became a mechanism for avoiding harm to the soul.”

  Disgust, as an emotion exclusive to humans, also helps put distance between us and the rest of nature. It is a crucial component of the civilizing process. Rozin points out that anything that reminds us that we are in fact still animals can elicit feelings of disgust. This includes bodily secretions,* sexuality, and death. But for Rozin it is the third term here that is the most important.

  “The prototypical odor of disgust is the odor of decay,” he points out, “which is the odor of death.” Thus disgust can be understood as a defense against our fear of death, another emotion that happens to be unique to our species† Rozin says that people who score high on psychological tests for “disgust sensitivity” also score high on tests measuring the fear of death.

  Putrefaction is repulsive to us because it reminds us of our ultimate fate, which is to have the noble and intricate form of our bodies disintegrate into a suppurating, stinking puddle of formlessness, then to be returned to the earth as food for the worms. This work of decomposition will be performed by bacteria and fungi, and the method they will deploy will be fermentation. Oddly, it is this process of decomposition that disgusts us, not the final result of that process: Rotting flesh is disgusting, but skeletons are not.

  So why should we ever be attracted to the very processes and products that, for the very good reasons Rozin gives, repulse us? Surely this is perverse. Yet if disgust is in fact one of the ways humans draw a line between themselves and the other animals, then to deliberately put ourselves in situations that elicit disgust may allow us to underscore and enforce that distinction. Perhaps we “enjoy” the experience of disgust for the flattering things the reaction implies about us—the wrinkling of the nose a visible index of our superiority and refinement.

  I became curious to know what Stillwaggon would have to say on the subject, and in the middle of my journey through the literature of disgust, I went looking for him online. Something had raised my antennae—didn’t smell quite right—when Sister Noëlla told me he hadn’t published. Stillwaggon didn’t sound like a man who could keep his views under a bushel basket even if he tried. When I searched his name, I found no books or Web sites, but I did find a Facebook page, and there on its wall a URL. Bingo: In large type the words “Cheese, Sex, Death and Madness” popped up on my screen, above a photo of an aproned man stirring a copper vat of milk, next to a photo of a particularly hideous cheese oozing yellow from its broken crust.*

  The Web site, half in French and half in English, was itself an aromatic ferment of truly wild ideas
about, well, sex and death and cheese, which Stillwaggon defined as “nature imperfectly mastered.” This struck me as a pretty good definition for fermentation in general. (If not for the entire human enterprise.) He went on to describe cheese as “an incarnate Passion Play, unfolding in its lifetime (briefer, in general, than our own) all the characteristics of the newborn, of juvenility and adolescence, of maturity and of decrepitude.” Cheese was flesh, heir to all its glories and mortifications. On the home page I clicked on “Attraction & Repulsion” and found this soaring, overripe, and ungrammatical flight of cheesy exegesis:

  “Cheese shares the same ambiguity of attraction/repulsion which marks and characterizes our genital and anal zones as passage from the scrubbed and well-aired exterior toward the organic, unsurveyed and uncontrolled interior: infernal microcosm fermenting, composting, the seething haven of impersonal microbiota. …

  “In both domains—the cheese and the sex—we are drawn to the limits of our comfort zone. Both zones of experience therefore invite us to exceed our limits, to test, to uncover, to abandon our reserve, to relativize our notions and principles—of limit, of desirable, of good & bad, of attractiveness and hideousness. The direction of this discovery is from pure and simple toward impure and complex, from a formal, cared-for aesthetic toward a formlessness, an aesthetic of abandon and degradation.”