Fermentation makes a comeback universe in a jar

29/3/2018 Fermentation makes a comeback - Universe in a jar
https://www.economist.com/news/christmas-specials/21732694-dinner-tastes-best-pre-digested-fermentation-makes-comeback 1/6
Universe in a jar
Fermentation makes a comeback
Dinner tastes best pre-digested
Christmas issue 2017
Print edition | Christmas Specials Dec 19th 2017 | LIBERTY, TENNESSEE
SANDOR KATZ’S kitchen is an alchemist’s laboratory. Glass jars filled with grains
and spices both common and unusual—oat groats and rice, millet and dried
tapioca pearls, sugar and liquorice, dulse and mauby bark—line ceiling-high
shelves. Beneath them sit carboys filled with homemade meads, fruit wines and
perry. In glass jars and ceramic crocks on the broad central table, the alchemist’s
assistants—trillions of bacteria—transform red cabbage into crisp sauerkraut with
a hint of caraway, deep green summer cucumbers into fizzingly sour olive-coloured
pickles, carrots and green cabbage into bracing pao cai (Chinese pickles), and sliced
daikon radish into an extraordinary kimchi. Its powerful funk blooms into the room
as soon as Mr Katz removes the crock top.

Fermentation is the world’s oldest method of storage and preservation. It arose out
of practicality. It is easiest to grow cabbages, and other crops, if you synchronise
the planting and harvesting; but you cannot eat them all at once. If you shred, salt
and pack those same cabbages in jars they will last more or less indefinitely, and, in
the process, become much tastier.
People tend to think of fermented foods as
pickly and sour: that pao cai, for instance.
In fact, bread, cheese, yogurt, chocolate
and tea all undergo some kind of
fermentation. Bread depends on it to make
dough rise: yeasts, whether wild or lab-
domesticated, consume the simple sugars
found in flour. In bread, though, as in
chocolate, the microbes are dead at the
point of consumption. Unpasteurised
sauerkraut, kimchi and kombucha, on the other hand, teem with live bacteria.
To biologists, fermentation is the anaerobic metabolising of sugars. It is what the
yeast used to make bread, beer and wine does when it turns carbohydrates into
alcohol and carbon dioxide without the benefit of oxygen. But not all the processes
in Mr Katz’s kitchen are anaerobic. Tempeh, a Javanese food made from soya beans
inoculated with spores of Rhizopus, a parasitic fungus, requires air to circulate if
the mould is to grow into a solid cake around the beans. In his book “The Art of
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Fermentation”, Mr Katz (pictured) prefers a broader definition: “the transformation
of food by various bacteria, fungi and the enzymes they produce”.
Not all microbial transformations are desirable. Leave a head of cabbage in brine for
a week or a month and you will have delicious sauerkraut.
(http://cdn.static-economist.com/sites/default/files/external/2017/christmas-
issue-2017/recipe.html) Leave it on the kitchen counter for a month and you will
have a slimy mess. But the line between fermented and rotten is not always so
stark. Sometimes, like beauty, it exists in the beholder’s eye. With the exception of
some Nordic types, Westerners tend to be repulsed by stinky, fermented fish. But
they will happily eat stinky, fermented milk in the form of Gorgonzola or Stilton.
Many East and South-East Asians, who consume fish sauce regularly, eschew
cheese.
At the moment, though, people’s palates seem to be widening. Mr Katz teaches
fermentation workshops around the world to strangers who come together to salt
and squeeze root vegetables and trade SCOBYs (a “symbiotic colony of bacteria and
yeast”—the broad, slimy, vaguely organ-like disc that turns tea and sugar into
kombucha). Enthusiasts trade sourdough starters and kefir grains (at Bridge Farm in
Ambridge, the setting for “The Archers”, an enduring BBC radio series, they talk of
little else). Fermentation’s popularity seems in part a reaction against the last
decade’s fad for “molecular gastronomy”—using chemistry to transform the taste
and texture of food—and of a piece with other back-to-nature trends such as
foraging and cooking over open fires.

Microbiomial gastronomy
Fermentation produces delicious foods. But more than that, it connects humans to
the invisible processes of life all—to the microbes that were here for billions of
years before humans arrived, and will persist for billions more after they have
gone. Fermentation enlists the microbes’ aid, proceeds on their schedules,
succeeds or fails according to their needs and rules.
The oneness goes deeper than that. The Buddhist notion of anatta, or non-
selfhood, is biologically true. People are not unitary beings; they are entire
universes for the “microbiomes” that live on and within them. More than 700 types
of microbe live in a typical person’s mouth. The gut bustles with bacteria by the
trillion which assist with digestion, helping determine health, weight and even
mood. Ferments made by different people can vary because of the different
microbes transferred from their makers’ hands. Some pioneers have tried
producing cheese from bacteria found in their armpits and navels.
Fermentation extends the microbiome in time and
space, allowing its microbial members to start
digesting things before they even reach the lips.
The micro-organisms thus pressed into service
may be carefully chosen, and passed down through
the generations. They may be simply introduced
through “backslopping”—using a bit of a previous ferment to start the next batch.
Or they may be left to happenstance: lambic beers and some sourdough starters use
wild yeasts naturally present in the air or on bits of organic material. This entails
some risk. A successful sourdough starter will smell slightly sour and pleasantly
yeasty; one where the wrong microbes won will smell like vomit or putrefaction.
Nearly everyone on Earth consumes some form of fermented food regularly. In
most of the world, this is just the way things have always been. The current revival
of interest in the West is in part simply a return to the norm; in the 20th century
much of Europe and America descended into peculiar ignorance on the subject.
The decline of fermentation in the West can largely be put down to the
concentration of agriculture. In 1870, agriculture employed almost half of all
American workers; each farmworker could produce enough to feed just five others,
and people knew a great deal about how food was stored and prepared. Today only
1.4% of American employees work on farms. This has freed people from the need to

spend hours churning butter from cows they milked themselves, or manually
shredding fields of cabbage and turnips to salt for the winter. It has made cheap
food abundant and moved workers into more economically productive jobs. But, as
Mr Katz notes, the move from farmhouse porches and cellars to factories has
rendered once quotidian processes mysterious.
It has also made food more predictable, and mass production easier. Commercial
yeast acts quickly and flawlessly. Sourdough starters—slurries of flour and water
that attract yeasts and lactic-acid bacteria—take days to create, and produce
different tastes from place to place. Sourdoughs taste better than the squishy,
shrink-wrapped loaves on grocery-store shelves, but brands require consistency,
and not everyone wants to bake (or pay for) an artisanal loaf, however delicious,
whenever they want toast.
Pasteurisation also had a hand in fermentation’s Western waning. Not all bugs are
good bugs, and Louis Pasteur’s innovation of heating milk and other foods enough
to kill off bacteria undoubtedly saved many lives. But it brought with it the idea that
all bacteria were germs to be ruthlessly extirpated, rather than a workforce to be
exploited—or allies to be encouraged.
Rob Knight, who heads the American Gut Project at the University of California, San
Diego and researches the links between the microbiome and general health, says
that lactic-acid bacteria do in the sauerkraut crock or the yogurt pot what they do in
the gut: render their environment unfriendly to an array of unhealthy fungi and
bacteria. Mr Knight has found that people who eat fermented foods tend to have
more diverse gut bacteria. This, in turn, tends to be associated with better physical
and mental health, though whether a bountifully biodiverse gut is a cause or an
effect of better health remains unclear.
Pasteurised foods, with and without the addition of acetic acid, do stay fresh
longer; that which is not pasteurised is still, sometimes, unsafe. But fermented
foods thus preserved tend to be more astringent and less subtle than those that live
on in the consumer, and they have none of their biological diversity.
When it relies on ambient microbes fermentation is incredibly local; but the
natural home for the new enthusiasm, as for all today’s enthusiasm, is the
cosmopolitan internet. On Facebook groups bakers can post pictures of their
sourdough breads to collect tips (“strengthen the gluten by starting with cold
autolyse without starter or salt first”) and praise. Kombucha makers can offer their

SCOBYs to willing takers (“If no one claims in two days, it’s compost”). And brewers
can discuss the finer points of Brettanomyces (a kind of wild yeast), the implications
of brewing with sorghum and the finest fashion to keep their foeder in fine fettle.
On Etsy, an e-commerce site selling handmade crafts, bakers can buy sourdough
starters with a story. One of those sold by Ken Greenlaw, somewhat unappetisingly
known as “Bavarian Black Death”, claims to have originated in Oberammergau in
1633; another, from Egypt, boasts of being “as old as the pyramids”. Have they been
independently, verifiably traced back to their supposed origins? Not exactly: “You
take it with a grain of salt,” says Mr Greenlaw (referring to the stories, rather than
the starters).
Stories apart, most starters originated in obscurity. But internet-enabled
enthusiasm means few of any quality will end up there; no promising culture of
helpful microbes need ever be lost again. Eric Rusch has been selling his starter
online for 12 years. “If anything happened to my starter,” he says, sounding like
nothing so much as a proud father, “I could send out an e-mail to 30,000 people
and I’d probably get it back. It’s neat to think that people all over the place are
making bread that started out here and touched my hands.” It is not merely in the
microbiome that ferments can create new communities.
This article appeared in the Christmas Specials section of the print edition under the headline "Universe in a jar"

Fermentation makes a comeback universe in a jar

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Fermentation makes a comeback universe in a jar