Cooked: A Natural History of Transformation (25 page)

Which is of course precisely what is going
on in a long-simmered stock: The long protein chains in the meat are breaking down into
their various amino acid building blocks, glutamate chief among them. In fact, chicken
stock is loaded with glutamate, which has been contributed not only by the protein-rich
meat but by the slow cooking of the aromatic vegetables as well. Also present in meat
stocks is
inosinate, which when combined with glutumate creates a
perception of umami much greater than the sum of its chemical parts.

But though umami can make a food taste
“meaty,” meat is only one of the many sources of glutamate. (That’s
why “savoriness” is probably a better translation for umami than
“meatiness” or “brothiness.”) Ripe tomatoes, dried mushrooms,
Parmesan cheese, cured anchovies, and a great many fermented foods (including soy sauce
and miso paste) contain high levels of glutamate, and can be added to a dish to boost
its quotient of umami. This property of ripe tomatoes surely explains why so many of the
braises I made with Samin called for a “tomato product”—canned tomatoes, or
tomato paste—in addition to stock or wine. Occasionally we threw in a Parmesan rind,
too, or some dried porcini or a squirt of anchovy paste. (And the reason we sometimes, à
la Julia Child, browned our meat in bacon fat? Because bacon is a veritable umami bomb,
containing all of the umami compounds that have thus far been identified.) I
didn’t know it at the time, and nor did Samin, but all these additions were ways
to augment the umami in our dish, and the reason there was always more than one of
them—tomato plus Parmesan, or stock plus dried mushrooms—was no doubt to exploit the
synergistic properties of this particular taste. Umami, I realized, is the quasi-secret
heart and soul of almost every braise, stew, and soup.

I say “secret” because umami
works in somewhat mysterious ways, at least compared with sweet, salt, bitter, and sour.
Encountered in the purified form of monosodium glutamate (MSG), glutamate doesn’t
taste particularly good, or for that matter much like anything at all. To work its
magic, umami needs to be in the company of other ingredients. A bit like salt, glutamate
seems to italicize the taste of foods, but, unlike salt, it doesn’t have an
instantly recognizable taste of its own.

The other mystery about umami is how it alters
the texture as well as the taste of many foods—or, more accurately, our perception of
its texture. Add umami to a soup and eaters will report it is not just
“heartier” but actually thicker, too; the umami taste appears to have
synesthetic properties. It makes a liquid seem less like water and more like food.
It’s possible that the umami chemicals activate not only the sense of taste in our
mouths, but also trip the sense of touch as well, creating an illusion of
“body.”

What I learned about the properties of umami
made me want to run some experiments with dashi, the classic Japanese stock. If pot
dishes owe so much of their power to umami, then making them with dashi—a cooking water
designed, albeit unwittingly, to contain as much umami and as little of anything else as
possible—seemed worth trying. It sounded to me like the Ur–cooking liquid. So,
naturally, I wanted to make some.

At least until you understand the science of
umami, dashi seems like a thoroughly improbable concept: a stock made from dried
seaweed, shavings from a cured fish, and, optionally, a dried mushroom or two. But it so
happens that each of those items contains a different one of the three principal umami
chemicals. Put all three together in water and you get synergies that vastly amplify the
umami effect. Dashi, which has been made in Japan for more than a thousand years, is a
classic example of the wisdom of cuisines: how, strictly by trial and error, a
traditional culture can perfect a chemistry in food that is not fully appreciated until
long after the fact.

With my dashi experiments, I was venturing
well outside Samin’s culinary orbit. She doesn’t have much experience of
Eastern foodways. But she was able to direct me to someone who did: a young Japanese
American cook by the (unsurpassed) name of Sylvan Mishima Brackett.
When I e-mailed him to say I was interested in learning how to make dashi, Sylvan
invited me over to the tiny, converted garage behind his house where he cooks, using
little more than a hot plate.

What Sylvan did have, and what is difficult
to find in this country, is a block of katsuobushi, or cured bonito, that he had brought
back with him from a recent trip to Japan. Katsuobushi looks like a toy submarine carved
out of a block of hardwood, perhaps walnut. It is as hard and fine-grained as walnut,
too, making it impossible to cut with any tool less sharp than a woodworker’s
plane. Which is in fact what is traditionally used to coax shavings from
Katsuobushi.

Sylvan had been to a katsuobushi factory in
Japan, and he described the absurdly laborious process by which it is made. After the
bonito is filleted into quarters, the fillets are simmered in water for two hours and
then put on racks in a room in which an oak fire is burned for part of each day for a
minimum of ten days. After that, the dried blocks of fish are scraped, taken out in the
sun, and then inoculated with a fungus called koji (
Aspergillus oryzae
), before
spending ten more days in a “molding room.” That process—scraping,
sun-drying, inoculating—is repeated three times, before the block—now completely
desiccated and as hard as rock—is ready to be used. Here was an extreme instance of a
pot-dish ingredient that was itself a complicated dish with a long recipe that called
for an ingredient that
itself
had an unbelievably complicated recipe.

Sylvan used a whetstone to sharpen the blade
on his plane and put me to work shaving katsuobushi. The block was actually considerably
harder than wood, and it took a strenuous effort to accumulate even a small pile of
shavings. The grain that the plane raised was a beautiful shade of salmony pink; how is
it, I wondered as I worked, that the flesh of a fish and a tree could have so similar a
structure? Meanwhile, Sylvan cranked up his hot plate and put a pot of water on to boil,
to
which he added a foot-long section of kombu. Kombu is air-dried
kelp, one of the richest sources of glutamate in nature. Out of the package, it wears a
cloak of white salt that is basically monosodium glutamate. Sylvan said the very
best-quality kombu comes from (wouldn’t you know it?) a specific beach on the
northern coast of Hokkaido. He also mentioned that soft water was best for extracting
the maximum flavor from the ingredients, and that in fact the word “dashi”
means “extraction.”

But if the backstory of the ingredients in
dashi is complicated, the recipe for making it is fairly straightforward and, for a
stock, quick and easy—less than ten minutes from start to finish. Sylvan dropped a sheet
of kombu into a pot of cold water, heated it to a point just shy of the boil, and then
removed the now green and floppy length of kombu with a pair of tongs. If the kombu
reaches a full boil, he explained, the dashi will turn out bitter. At this point, the
liquid gave off only the faintest scent of brininess. Unlike the kombu, the bonito
flakes need to be boiled to release their flavor, so, as soon as the pot began to roil,
Sylvan dropped in a big handful. The pinkish shavings danced crazily on the surface and
then, as they rehydrated, began to sink to the bottom. They had only been in the water
five or six minutes when Sylvan poured the stock through cheesecloth and discarded the
residual flakes. The resulting liquid resembled very weak tea, an almost perfectly
transparent pale gold. As the liquid cools, you have the option of adding a dried
shiitake mushroom. But that’s all there is to it.

I bent over to smell the finished dashi. It
reminded me of a tide pool: briny, with the faintest suggestion of decay—the beach at
low tide. I dipped a finger into the cooling liquid. It had very little taste to speak
of; some saltiness, but not too much—sort of like a freshwater version of the ocean.
Brackish. Compared with a real stock, it was pallid stuff; you would never think of
sipping it as a soup. But the pale liquid contained large amounts of the three main
umami chemicals—
glutamate from the kombu, inosinate from the bonito,
and guanylate from the mushroom—each of them extracted by the water.

Sylvan gave me some bonito flakes and kombu
to take home, and over the course of the next several days I made my own dashi and
experimented with it. The first thing I tried was a dipping sauce. To a small bowl of
dashi I added a tablespoon each of soy sauce, mirin, and rice wine vinegar, as well as a
small handful of chopped scallions and ginger. It was remarkable stuff: Anything dipped
in it—a chicken breast, some soba noodles, a piece of pork—received an uncanny boost in
flavor, somehow tasted more platonically itself. (And more platonically Japanese.) Next,
I tried the dashi as a braising liquid, for beef short ribs and then for a pork loin,
combining it, again, with some soy sauce, mirin, vinegar, and sake, as well as some miso
paste. The result in both cases was a rich and satisfying dish, somewhat lighter than
the braises that Samin and I had made, though no less intensely flavored. I have not yet
tried dashi in a non-Asian dish; that might be crazy, I don’t know, and Samin
would probably flip if I proposed it. But dashi itself is not a flavor principle,
exactly—it’s more like an italicizer of flavors—so it might well work with another
cuisine. Nothing about dashi, when tasted by itself, prepares you for what it does in
concert with other flavors. I’m starting to think of it as magic water: hydrogen
and oxygen and amino acids and something no one knows.

One curious fact I stumbled on in my umami
research was that human breast milk is rich in this particular taste, and contains
relatively large amounts of glutamate—as it happens, nearly the same amount of glutamate
as an equivalent amount of dashi. It stands to reason that everything in milk is there
for an evolutionary reason; since every
chemical compound in it comes
at a metabolic cost to the mother, natural selection would quickly dispense with any
constituent of milk that didn’t do the infant some good. So what good does all
that glutamate do?

There are a couple of possible explanations.
Bruce German, a food chemist at the University of California, Davis, who analyzes human
milk in order to better understand our nutritional needs, believes that the glutamate
supplies an important nutrient to the growing infant. Besides being a flavor, this
particular amino acid is a cellular fuel and molecular building block of special value
to the stomach and intestines of the growing infant. In the same way that glucose is an
ideal food for the brain, glutamate is a perfect food for the gut, which might explain
why we’re born with taste buds in the stomach that can detect it.

All that glutamate in breast milk might be
doing something else as well: conditioning the baby to like the taste of umami, that
being (along with sweetness) one of the first and most abundant tastes it encounters in
mother’s milk. This preference is highly adaptive for
Homo sapiens,
since
we require a diet rich in the proteins that umami helps us to recognize and seek
out.

But could it be that, for us, the taste of
foods rich in umami also sounds deep Proustian echoes, bearing us back to memories,
however faint, of our very first food? Is it merely a coincidence that so many of the
things we think of as “comfort foods”—everything from ice cream to chicken
soup—traffic in tastes of either sweetness or umami, the two big tastes first
encountered on the breast?