What Einstein Kept Under His Hat: Secrets of Science in the Kitchen (41 page)

Nightmare scenario: I say they’re safe. You eat some and get a headache. An opportunistic lawyer tells you, “You have a case.” He sues me and the food company, stuffs a jury box with migraine sufferers, and wins a $2 million settlement from the company plus $500 from my threadbare writer’s pockets. He takes $1.5 million for himself and runs off after another ambulance, while after paying court costs you’re left with the price of a bottle of aspirin.

So should I say that smoked foods are safe? Okay, I’ll take the plunge.

Yes, the smoke chemicals in purified liquid smoke are safe in the small amounts you’ll encounter in smoke-flavored foods. So sayeth the FDA. Sue them.

Real, gaseous smoke, however, can be quite another story. The decomposition of wood (and tobacco and grilled steaks and hamburgers) by intense heat, a process called
pyrolysis
, can produce highly carcinogenic 3,4-benzopyrene and other so-called polycyclic aromatics (PCA’s). But none of these chemicals has been found in commercial, purified liquid-smoke products. On the other hand, liquid smoke, like its gaseous parent, contains bactericidal and antioxidant chemicals, such as formic acid and phenolics, that may even make a positive contribution to your health.

A friend who owns a Japanese restaurant told me that the green paste you get in restaurants (including his) isn’t real wasabi, but only a green-tinted horseradish. Was he making excuses?

....

N
ope, he was serving you the real scoop, if not the real stuff. I, too, have a friend who owns a Japanese restaurant, and he confided the same to me.

Most Americans who order sushi in a Japanese restaurant will recognize the condiments on the platter. One is a tangle of thin slices of pickled ginger, intended for palate-cleansing between bites, and the other is a glob of fiery green “wasabi.” Genuine ginger, yes, but real wasabi, probably not. Most people outside of Japan have never tasted real wasabi.

So what
is
that ball of green paste on your plate at the local sushi bar? It’s a blend of horseradish, mustard, cornstarch, and yellow and blue dyes, packaged as a dry powder to be made into a thick paste with water. Put more than a dab on your tongue and the incendiary stuff will clean your sinuses, make your eyes water, and nearly take your head off. The experience of real wasabi, on the other hand, is surprisingly refined.

True wasabi is a green-hued underground stem, or rhizome, known botanically as
Wasabia japonica
or
Eutrema japonica
, among other names. And it’s not pretty. Long, stringy roots grow out of its sides, and even when cleaned up, it looks like a knobby sweet potato on a bad hair day. Wasabi is extremely hard to grow, requiring highly specialized conditions in icy waters, and there are only about five growers worldwide. It costs anywhere from $20 to $80 a pound wholesale and about $100 a pound retail. That’s why it’s rare to find the real thing outside of Japan.

But I was lucky enough to find some.

Andy Kikuyama, owner of KIKU, a Japanese restaurant in Pittsburgh, set up a taste comparison for Marlene and me. He placed two tiny saucers on the table. In the one on the left, a knob of the familiar bluish-green impostor. In the one on the right, a knob of pale yellowish-green, genuine wasabi. It was hard to tell them apart by their appearance.

With a chopstick, we picked up a tiny bit from the familiar mock wasabi in the left-hand dish and placed it on our tongues. The texture was a bit gritty and chalky, and the experience was one of intense heat, with no flavor to speak of.

Next, we tried the real thing. The texture was that of a finely grated vegetable. The taste was slightly nutty, slightly sweet. The heat was instant and bright, more of a brief kick than the long burn of chili peppers; it subsided into a very pleasant, mild vegetable flavor that even people normally averse to hot food might enjoy.

“Americans use much more ‘wasabi’ than the Japanese do. They seem to want punch, not subtlety,” Andy says. “We keep both kinds in the restaurant, but we always serve the real wasabi with white sashimi—thin slices of raw fish eaten as is, usually yellowtail, snapper, and flounder. When there are many flavors in a dish, such as in cold soba noodles or intricate forms of sushi, we serve the horseradish type, because when mixed with soy sauce the subtlety of the real wasabi is wasted.” He added that wasabi is never used in cooking because it loses its flavor when heated. (I explained that isothiocyanates, the pungent chemicals in wasabi, are thermally unstable, but I’m not sure Marlene and Andy were listening.)

Until a few years ago, all true wasabi came from a small number of growers in Japan. But now an American company, Pacific Farms, in Florence, Oregon (
http://www.freshwasabi.com
), grows the real thing and markets it in paste form.

It is a tradition in our house for my husband to grate horseradish (the traditional bitter herb) for our Passover seder. He usually makes a lot, enduring burning eyes and sinuses to prepare that delightful condiment. However, the leftovers lose their potency and become quite mild after a couple of days. How can we keep it spicy and potent for the whole eight days of Passover, instead of shredding the root daily?

....

T
he pungent and tear-producing (lachrymatory) compound in the essential oil of grated horseradish is
allyl isothiocyanate
, commonly known as mustard oil. (It’s in black mustard seeds also.) It is created when the plant cells are cut apart by the grating, which releases an enzyme called myrosin and a compound called sinigrin. These two chemicals were previously isolated from each other in different parts of the cells, but when released together in the presence of water, they react to form the allyl isothiocyanate.

Once the oil has been produced, it begins to vaporize, releasing its strong vapors into the air. The vapor, however, is not very stable and dissipates after ten or twenty minutes.

Keep the excess grated material in a tightly sealed jar in the refrigerator, which will contain the vapors and slow down their release. Or try mixing the grated horseradish with chicken fat (technically known as
schmaltz
), another Passover staple. When refrigerated, the solidified fatty coating will seal in the pungent vapors.

Better yet, grate the horseradish into enough vinegar to dampen it, as the commercial producers do. The acid inhibits the allyl isothiocyanate-producing reaction by deactivating the myrosin enzyme on the surfaces of the shreds. Then when you chew the horseradish, you break open more cells, more enzyme is released, and the pungency will be born again, albeit not Christian.

I have a small electric coffee grinder that I use for grinding dried spices such as mustard seed and peppercorns. But I’ve noticed a strange occurrence. After I ground some cloves, the grinder’s plastic hood was pitted and actually softened around the edges. And now I can’t wash the scent of the cloves out. Do whole cloves have any unusual corrosive properties?

....

Y
es, they do.

Cloves are probably the strongest of all aromatic spices, containing up to 20 percent of an intense, sweetly pungent essential oil.

Originating—appropriately enough—in the Spice Islands, now part of Indonesia, they are the dried flower buds of the tropical evergreen tree
Syzygium aromaticum
. Dried clove buds have a stem and a head, a shape that gave them their name,
clove
, from the Latin
clavus,
“nail.” In the United States, they are most often seen protruding like spikes from the surfaces of hams. (I hate it when I bite into one, don’t you?)

Not surprisingly, cloves contain oil of cloves, the main chemical ingredient of which is
eugenol
, known familiarly to chemists by its nickname, 2-methoxy-4-(2-propenyl)phenol. You may at one time have had it applied to a tooth by your dentist as an analgesic and antiseptic.

Or, as I have done in Jakarta and on Bali, you may have smoked a few Indonesian clove-flavored cigarettes. These cigarettes, called
kreteks
, are filled with two parts tobacco and one part ground cloves. Indonesia’s passion for
kreteks
uses up approximately one-half of the world’s clove production.

Eugenol is a phenol, and phenols can have acidic and corrosive properties. In your case, the eugenol invaded, dissolved, and softened the grinder’s transparent plastic hood, which is probably made of polymethyl methacrylate, or Lucite. The aroma became permanently embedded therein.

I’m afraid you now own a dedicated clove grinder. Buy another coffee grinder for your less rapacious spices, and wash it out well after each use before you use it for coffee. Most other spices won’t permanently flavor the grinder.

In Brittany, I saw salt containers made of pottery that are said to keep salt dry, even though they’re open near the top so you can insert a measuring spoon or reach in with your fingers to take a pinch of salt. How do they work?

....

T
his kind of container, common in France and England but also available in many stores in the United States, is called a salt pig. It is shaped like one of those wide-mouthed air intakes on ships that some people think are foghorns: squat, vertical cylinders bent into a right angle.

Salt pigs are made of pottery or terracotta that is not glazed on the inside and hence remains porous. The open pores provide a huge amount of surface area that can adsorb water vapor. The sea salts harvested in Brittany are particularly in need of this drying effect; they’re often damp if they’re not refined. That’s because they contain small amounts of calcium chloride, which is
hygroscopic
—that is, it absorbs moisture from the air. Common American table salt contains a small amount of a drying agent, so that “when it rains, it pours.”

And yes, you can keep kosher salt in a salt pig.

A pottery salt pig for storing and serving salt. The porous, unglazed interior surface adsorbs moisture and helps keep the salt dry.

A few years ago at “National Store X,” a vial containing two vanilla beans cost $4.50. Now the price is $9.50. A few years ago in the same store, an 8-ounce bottle of Madagascar Bourbon Pure Vanilla Extract cost $11. Now the price is $20. With vanilla prices skyrocketing, many people are turning to Mexican vanilla. Is this product real or artificial? Based on its cheap price, I suspect it might be artificial.