46 THENEWYORKER,SEPTEMBER30, 2019
“Which would be more dangerous—a bear, or a man in a bear suit?”• •
said to evoke cat urine.) So the compa-
ny’s scientists had to learn how to erase
those flavors, even as they were learn-
ing the subtleties of the aroma and taste
they were trying to emulate.
One morning in Impossible’s lab,
Brown showed me a gas chromatograph–
mass spectrometer, which is used to
identify the molecules that appear in
meat as it’s cooked and to link those
molecules to odors. “Some poor schmuck
has their nose stuck in here for forty-five
minutes,” Brown said, indicating a plas-
tic nose mold that protruded from the
machine. “You have to bunny-sniff at a
very high rate, often trying to charac-
terize molecules you’ve never smelled
before.” He looked at a handwritten list
from the last assay: “You might say,
‘We’ve got to get rid of “Band-Aid,” or
“skunk,” or “diaper pail”’—but don’t
judge, because all of those together make
up ‘burger taste.’”
Most veggie burgers are formed by
an extruder, a machine that operates like
a big pressure cooker, using heat and
compression to replicate meat’s fibrous
morphology. Brown suspected that the
key to a truly meaty plant burger was an
ingredient. He had a hunch about heme,
an iron-carrying molecule in hemoglo-
bin (which makes your blood red), whose
structure is similar to that of chlorophyll
(which enables plants to photosynthe-
size). David Botstein, a geneticist who
sat on Impossible’s board, told me, “If
you understand biochemistry, you un-
derstand that heme, more than anything
else, is a central molecule of animal and
plant life.” As Brown was beginning to
experiment, he pulled up clover from
behind his house and dissected its root
nodules, to see if there was enough heme
inside to make them pink. (There was.)
In Impossible’s microbiology lab,
Brown told me, “An interesting, ex-
tremely speculative idea is that there’s
an evolutionary advantage to human be-
ings in seeking out heme. It’s a cue that
means ‘There’s a dense source of pro-
tein and iron nearby.’” The first time
that Impossible made a burger with
heme, he said, “it tasted like meat, and
within six months we had compelling
evidence that it was the magic ingredi-
ent that gives meat its flavor.”
In 2012, the company tested heme
from thirty-one sources, ranging from
tobacco plants to geothermal-spring
water. Myoglobin from cows, the obvi-
ous candidate, oxidized too quickly (which
is why ground beef goes brown in your
fridge). Soy leghemoglobin performed
best, so Impossible built a dozen ma-
chines to try to harvest it from the root
nodules of soy. “We even rented a street
sweeper and fed the soy plants in there,”
Brown told me. Nothing worked. “We
flushed a year or more and half of our
seed funding on this project I’m to blame
for—the total low point,” he said. They
ended up manufacturing heme by genet-ically modifying yeast with a snippet of
soy DNA. Yeast is usually white; Impos-
sible’s yeast, made in fifty-thousand-gallon
tanks, is the foamy red of cocktail sauce.
Impossible’s first burger, built around
wheat protein, launched in 2016, at four
high-end restaurants: Cockscomb and
Jardinière, in San Francisco; Crossroads
Kitchen, in Los Angeles; and Momo-
fuku Nishi, in New York. An improved
formulation, introduced last January,
swapped out wheat for soy and was not
only gluten-free but also lower in fat and
cheaper to manufacture. Traci Des Jar-
dins, the chef behind Jardinière, said,
“The 1.0 version had a mushy mouth-
feel, and it would adhere to surfaces and
sear in a way that meat doesn’t. This ver-
sion has a more toothsome bounce, and
it doesn’t fall apart in a Bolognese sauce.
The 2.0 really does behave just like beef.”E
ven those sympathetic to Brown’s
mission fret that taste and mouth-
feel won’t matter if the desire for meat
is hardwired by evolution. Maple Leaf
Foods, a Canadian company, is build-
ing a three-hundred-million-dollar fa-
cility in Indiana to make alternative
proteins. But its C.E.O., Michael Mc-
Cain, told me, “The human body has
been consuming animal protein for a
hundred and fifty thousand years, and
I honestly think that’s going to con-
tinue for a really long time.”
Climate change, which now drives
our hunt for meat substitutes, originally
drove hominids to turn to meat, about
two and a half million years ago, by
making our usual herbivorean foodstuffs
scarce. Eating animals added so much
nutrition to our diets that we no longer
had to spend all our time foraging, and
we developed smaller stomachs and larger
brains. Some scientists believe that this
transformation created a powerful in-
stinctive craving. Hanna Tuomisto, a
Finnish professor of agricultural science,
recently wrote, “This evolutionary pre-
dilection explains why eating meat pro-
vides more satisfaction compared to
plant-based food and why so many people
find it difficult to adopt a vegetarian diet.”
An inborn meat hunger remains a
hypothesis; meat is the object of many
human urges, including the urge to con-
struct all-encompassing theories. In
the book “Meathooked,” Marta Zaraska
writes, “We crave meat because it stands