Milk (28 page)

Yogurt was also one of the
staffs
of life, from prehistoric times on, in the regions I have called the
Diverse Sources Belt and the
Bovine and Buffalo Belt. Nobody knows how ancient it is. Though archaeological sites can be troves of evidence for such things as animal bones and plant seeds, less durable foods like milk products generally disintegrate and disappear fast. But yogurt must
be almost as old an article of diet as unfermented milk in the first Near Eastern centers of animal husbandry—and certainly became more important as regards settled culinary practice. Under the once inescapable reality of being produced during very hot weather with no refrigeration, milk is a fickle cooking ingredient; it turns into
yogurt or something yogurtlike within a matter of hours. In that state it is not only more stable than unfermented milk, but digestible by more people because of its reduced
lactose content.

Here it probably is a good idea to define yogurt, or to explain that it’s not strictly definable. The simplest description is: a mildly sour fermentation of milk colonized by lactic-acid
bacteria of the general kind called
thermophilic, or “heat-loving.” These not only tolerate but prefer temperatures that would knock some kindred microorganisms out of commission—110° to 120°F, a level not at all hard to achieve on a summer’s day in Yogurtistan or India.

Of course, the ambient air anywhere in the world is a soup of many miscellaneous bacteria, and the first wild fermentations of raw milk must have been a microbiological free-for-all with all kinds of edible, inedible, or positively dangerous results. Perhaps a series of lucky experiences encouraged populations of the right bugs to cluster around places where milk was being collected. Then at some unknown point, people learned to modify wild fermentation and give the desired bacteria a leg up on the competition by saving some of the last batch and using it to inoculate a new batch of milk.

It is tempting to think of yogurt-culture lineages stretching back into antiquity like royal dynasties. But as the professionals who grow bacterial cultures for industrial use know, keeping any strain pure and unchanging is impossible without the tools of modern science. From time to time natural yogurt “starters” will become easy prey for microbial enemies, or either lose their potency or develop somewhat different flavor effects through mutation. Nonetheless, it’s a reasonable guess that most yogurt through the ages has involved the combined action of two particular lactic-acid bacteria, or their ancestors. As they exist today, they are usually known as
Lactobacillus bulgaricus
and
Streptococcus thermophilus.
(In the last twenty years, specialists have rebaptized both with new names, but the older ones are still the most common.) As I use the term in this chapter, “yogurt” is the product of these two principal actors’ colonizing any sort of milk.

The starter method of putting certain chosen bacteria to work was a major if not completely foolproof advance in reliably turning milk into yogurt. A second leap forward—also of unknown date—came when people learned that yogurt became thicker and more flavorful if you boiled the milk and let it cool to just the right temperature range before inoculating it with the starter. (This also helped the starter bacteria more reliably get there first and multiply until
they created a slightly acid environment hostile to many harmful microorganisms.) Heating the milk to a boil, or even letting it cook down quite a bit before inoculating it, became a nearly universal practice among the world’s
yogurt-making peoples. This is why anyone who knows yogurt will raise an eyebrow at the words “
raw-milk yogurt”; I either avoid buying anything so labeled or try to question the seller about the term. If the milk really was raw, the yogurt will lack something in flavor and texture.

Certainly the first yogurt-makers didn’t scientifically classify the organisms that worked their wonders on milk. There are many thermophilic lactic-acid bacteria in addition to the two I’ve mentioned. In different regions, yogurt and yogurtlike foods probably involved combinations of organisms whose multiple alliances and shifts—and, incidentally, flavor effects—we may never be able to fully document. Sometimes the two basic yogurt bacteria got mixed in with others that preferred temperatures between about 90° and 100°F—the so-called
mesophilic organisms, which could start multiplying after the milk cooled below optimum yogurt-setting temperatures and might introduce other flavor notes of their own. In parts of the Caucasus and Central Asia, people also learned to introduce yeasts that triggered carbon-dioxide fermentation and produced some alcohol.

(For more on the resulting kefir and kumys, as well as the fresh fermented products that were developed in the cool climates of northern Europe, see “Cultured Milk and Cream.”)

The vigorous state of yogurt sales in Europe and the United States belies the fact that many people in the Western world still don’t really
get
the taste of yogurt as found east of the Adriatic. It was a very late import to the modern West—that is, a few immigrants here and there probably had managed to bring cultures from places like Greece or Syria before the twentieth century, but no one else had heard about it until 1907.

At that point grandiose reports from the Paris-based émigré Russian biologist
Élie Metchnikoff began to put yogurt on the Western map. Metchnikoff had concluded that yogurt as consumed by generations of hardy Bulgarian peasants was the secret of a greatly extended life span. The culturing organisms in yogurt, he thought, were in effect microbial policemen that could be deployed to keep the human colon free of crime—i.e., toxins produced by “putrefying” bacteria. These colonic pollutants were the essential cause of aging, but luckily the bacteria that manufactured them could be
knocked out by yogurt cultures. Without exposure to the “autointoxicating” products of the wrong germs, presumably everyone could live to the astonishing ages said to be commonplace in rural Bulgaria.

Today most of this scenario looks either oversimplified or positively crackbrained. But Metchnikoff’s claims meant the start of a new Western career for yogurt, far from its places of origin.
France was the first center of yogurt boosterism (and still is an important one). But pro-yogurt publicity circulated around the rest of western Europe from Metchnikoff’s lifetime (he died in 1916 at the respectable but scarcely breathtaking age of seventy-one) throughout the 1920s and ’30s. Bulgarian cultures were exported and propagated in various countries. A dogged if not delighted clientele embraced yogurt in the spirit that
Evelyn Waugh ascribes to John Beaver’s mother in the opening scene of
A Handful of Dust
(1934): “She held the carton close to her chin and gobbled with a spoon. ‘Heavens, how nasty this stuff is. I wish you’d take to it, John.’ ”

There is an irony here: Metchnikoff had achieved an accurate enough knowledge of the operative culturing organisms to make possible the scientific
commercial manufacture of finished yogurt—something that hadn’t existed in the countries where an incubating batch of yogurt was a daily kitchen miracle, not a standardized retail product to be sold in packages. Its new Western aficionados understood nothing about it but that it was supposed to be good for you, “nasty” or not.

On yogurt’s home territory, people had always eaten it not for health reasons but because it was a beloved food made and handled by well-known methods that controlled the final flavor. Without thinking, people knew how to make yogurt that was sourer, “sweeter” (i.e., less sour), creamier, milkier, thicker, thinner, or variously aligned along other scales of quality. To the early twentieth-century European sophisticates who bought yogurt as an exotic panacea, such niceties were meaningless. They disliked the lactic-acid sourness but assumed that it was a given, not an effect to be heightened or toned down by simple means like adding the starter under slightly altered circumstances (e.g., minute temperature variations) or draining whey at some optimal stage.

Gradually some European—and later, American—devotees began to like the taste of the early commercial yogurts. For those who didn’t, help eventually arrived in the form of sugar.

The Greek-born Spanish entrepreneur
Isaac Carasso founded one of the first yogurt-making businesses in Barcelona a few years after Metchnikoff’s death, naming it “Danone” for his son Daniel. During World War II, Daniel Carasso brought a new branch of the family business—which had already expanded into France and elsewhere—to the United States, changing the name to “
Dannon.” By this time some European producers were experimentally
adding sweetened fruit preserves to
yogurt. The American Dannon company, originally a tiny Bronx-based supplier to ethnic communities, adopted this tack in 1947. By the late 1950s sweetened yogurt was making giant strides on both continents.

Different approaches, for instance, “sundae-style” with sweetened fruit on the bottom or “Swiss-style” with the sweetening mixed in, gathered enthusiastic followings. Many—probably most—manufacturers soon took to using skimmed or partly skimmed instead of whole milk, offsetting the lack of body by adding powdered skim milk. The change reduced sweetened Western yogurt’s already tenuous connection with any sort of natural milk flavor but enabled promoters to call it “low-fat” or “fat-free.” Some manufacturers also lengthened the product’s shelf life by
pasteurizing it after incubation. Of course, this killed the live cultures that have always been part of yogurt. But since live cultures weren’t (and currently aren’t) mentioned in the FDA’s standards of identity, it didn’t stop anyone from calling the result “yogurt.” At about 1970 a new sales arena opened with the development of frozen yogurt, the most highly sugared avatar yet, which was inaccurately but very successfully promoted as a “lighter,” more healthful alternative to ice cream.

The bigger the business grew, the less it had to do with the yogurt of Bulgaria, Turkey, or anywhere else in the eastern birthplaces of this remarkable food. In effect, yogurt had been turned into a kind of premixed sweet-and-sour pudding or pseudo–ice cream, and whatever conflicted with that image came to be viewed as a defect by makers and consumers alike.

Most real yogurt, for example, “
breaks,” or releases whey, if it’s allowed to stand after a spoon is dipped in it. There is a simple reason for this. To dairy chemists, yogurt is technically a fragile semisolid “gel” formed during the culturing process when the lactic-acid content gets high enough to lower the pH of the milk and cause some changes in the shape of the
casein micelles. Their surface becomes bumpy and irregular enough to let them link up in a spongy lattice of casein strands holding whey in the interstices of the sponge. The casein and whey remain in this delicate arrangement—somewhere between the original milk structure and the kind of decisive curd precipitation that happens with cheesemaking—as long as the yogurt is left alone. Dip into it with a spoon, and you disturb the unstable gel enough to let whey leak out of the sponge. This harmless change does not affect flavor, and can be simply though temporarily reversed by stirring the whey back in. But because the separating phenomenon (chemists call it “syneresis”) bothered many consumers, manufacturers routinely started adding such fixes of the imaginary flaw as starches, gums, and/or pectin to keep the body of the yogurt intact.

Through all these vicissitudes, plain unflavored yogurt with nothing added retained a scattered following among Western consumers, mostly though not
entirely in ethnic enclaves. Then a
small but sturdy renaissance began to dawn for real
yogurt.

Some of the impetus came from the counterculture of the 1960s, which adopted homemade yogurt as a sort of “lifestyle statement.” Unlike some fashions of the time, this one has continued to gather converts ever since. Today nearly any cookbook claiming to be an all-purpose American kitchen bible will have directions for making yogurt. This certainly doesn’t mean that the general cooking population has a solid acquaintance with the age-old marvels of well and truly made yogurt, but at the very least we can say that no one now sees home yogurt-making as a hippie affectation.

At the same time, several other developments contributed to a serious upturn in the American fortunes of yogurt. One was a lively outpouring of cookbooks by such writers as
Paula Wolfert,
Claudia Roden, and
Madhur Jaffrey, celebrating cuisines to which real, fresh, rich, flavorful yogurt was crucial. This encouragement was eventually followed by a modest return of local artisanal dairying and a growing curiosity about a range of
fermented foods, as well as tremendous waves of immigration from India and many parts of the old Yogurtistan.

In other words, Americans who really want to explore yogurt now have unprecedented freedom to do so. Without wanting to diminish the importance of other fermented dairy foods, I have to say that for sheer culinary richness and diversity, the basic yogurt traditions of the eastern Mediterranean, the Near East, Central Asia, and India stand apart from anything else.

It should be pointed out that these are not the world’s only yogurt traditions. Yogurt or something close to it flourishes today among the pastoral peoples of East
Africa and some sizable ethnic minorities of
China. But I don’t know of any work that’s been done to document its uses in either area in terms intelligible to American consumers. On the other hand, people in this country can learn a great deal about the genius that people in India and the old Yogurtistan homelands have brought to cooking with yogurt. The recipes in this section barely scratch the surface.

Health claims on behalf of yogurt have persisted, and undoubtedly helped keep it before the public eye during the transition from a strange new import to a permanent part of the American diet. But I think it’s not easy to disentangle reality from myth. The only claims I’d subscribe to are that plain yogurt can be both a delicious and a nutritious food, that sufferers from moderate lactose
intolerance can digest it more readily than unfermented milk, and that it may help people get over gastric upsets.