Marlene Parrish - What Einstein Told His Cook 2

How hot is a hot pepper? The various species of capsicums are often listed in order of pungency, expressed in “Scoville units.” Back in 1912, Dr. Wilbur Scoville, an American pharmaceutical chemist, devised his Scoville Organoleptic Test for measuring just how hot a pepper tastes to a panel of tasters. He mixed the ground-up pepper with sugar water and diluted it over and over again until the tasters could no longer distinguish any pungency. (Homeopathic capsaicin, anyone?) The number of times it had to be diluted is known as the number of Scoville Units of heat for that pepper.

The species we call bell peppers or sweet red or green peppers are capsicums that contain little if any capsaicin; they score zero on the Scoville scale. At the other end of the spectrum, the heat of pure capsaicin itself didn’t disappear until a dilution factor of about 16 million. Mexican anchos registered 1,000 to 2,000, jalapeños 2,500 to 5,000, and cayenne 30,000 to 50,000. Habaneros, at 200,000 to 300,000, are the widely acclaimed champs, although that record has recently been surpassed by the Capsicum annuum var. aviculare or tepín , a tiny (quarter-inch) wild pepper found in the mountains of northern Mexico. Scoville never saw one.

Note, however, that the same species of pepper can have different pungencies depending on growing conditions, so quoting exact Scoville ratings and arguing about who can eat the hottest pepper—an unfathomable point of pride among self-proclaimed chili-heads—is pointless.

Moving on from peppers both real and misnamed, we find several other assertive spices whose blends of pungent chemicals in their essential oils can kick our foods up a notch. (Apologies, Emeril.) Table 6 shows which chemicals in several spices are primarily responsible for their pungency. You’ll note that the most pungent ones are in the mustard family of plants, the Brassicaceae.

No need to memorize the names in Table 6; they won’t be on the final. But notice how isothiocyanates are the main pungent chemicals of the mustard family. They are formed when the plants’ seeds or roots are cut or crushed and the cells rupture, whereupon an enzyme in one part of the cells reacts with certain sulfur-containing compounds in another part to form the isothiocyanate. ( Thio -in the name of a chemical compound indicates that its molecules contain one or more sulfur atoms.)

Allyl isothiocyanate is the very potent “hot stuff” in horseradish, mustard seed, and wasabi. It is also the primary component of mustard oil, which is used very sparingly in cooking, notably in some Chinese stir-fries.

Contrary to some scare stories that have made the rounds on the Internet, mustard oil has no chemical relationship whatsoever to the mustard gas—actually not a gas but an oily liquid sprayed as a mist—used by the Germans in World War I as a chemical weapon. It was called mustard gas only because of its sharp, acrid smell and because it irritates the skin like an old-fashioned mustard plaster. Of course, the irritation caused by mustard gas is infinitely worse: It kills rather than heals.

Mouths afire!

The capsaicinoids in hot peppers stimulate the same nerve endings in our mouths as heat does, but because they don’t create actual heat, sipping cold water to “cool” an overenthusiastic mouthful is useless.

Capsaicin oils are not very soluble in water, although they do dissolve in alcohol. But—alas!—beer, at about 5 percent, doesn’t contain enough alcohol to remove them from your burning tongue. Fortunately, however, tequila (at 40 percent alcohol or more) is better and is quite likely to be handy wherever too spicy foods are served.

Milk and sour cream are even better than tequila, because their protein molecules (mostly casein) are attracted to oils and drag them away, in much the same way as soap drags away oily dirt. But if you can’t bear to swap your tequila for milk ( ¡Ay, carramba! ), just chew a piece of bread or flour tortilla, which will abrade and absorb the oil from your tongue. And drink the beer anyway. Who needs an excuse?

Sidebar Science: What’s hot today?

WILBUR SCOVILLE’Shighly subjective method of determining pungency is gradually being replaced by more scientific methods. Using a technique known as high-performance liquid chromatography, or HPLC, chemists today can determine how much actual capsaicin and its relatives—dihydrocapsaicin, nordihydrocapsaicin, homocapsaicin, and homodihydrocapsaicin—a capsicum pepper contains. Capsaicin and dihydrocapsaicin together make up about 80 to 90 percent of the capsaicinoids in capsicum peppers. In pure form, Wilbur rated these two chemicals at 16 million Scoville units, while the other three scored a relatively wimpy 9,000 or so.

Chili Pepper Hash Browns

Chili peppers, even of the same variety, are not all created equal. Some of them may be quite hot, others relatively mild. If yours turns out to be mild and will not lend enough oomph to the dish, add a sprinkling of hot red pepper flakes to taste. This dish should be definitely spicy.

Preparation of the peppers and potatoes can be done in advance, allowing only about 12 minutes to finish the dish before serving. Try these hash browns alongside roasted chicken. In the unlikely event that you have leftovers, reheat the hash for breakfast for serving with a softly poached or over-easy fried egg.

2 large sweet potatoes, scrubbed but not peeled

1 tablespoon olive oil

1 tablespoon unsalted butter

1 small onion, finely diced (about 1/3 cup)

½ small sweet red pepper, finely diced (about ½ cup)

½ small sweet green pepper, finely diced (about ½ cup)

¼ cup chopped fresh chili pepper (ancho, serrano, poblano, or jalapeño), stemmed and seeded

Kosher salt

Red pepper flakes, optional

1.Bring a large saucepan of salted water to a boil. Add the whole sweet potatoes and simmer for 10 minutes; they will be quite firm. Drain. (Don’t even think about cutting them in half or cooking any longer, or they will go to mush.)

2.When the potatoes are cool enough to handle, peel them, cut lengthwise into slabs, and then cut the slabs into ¼-inch dice. You should have roughly 3 cups.

3.In a large skillet, heat the olive oil and butter over medium heat. Add the onion and all the peppers and cook, stirring, for 1 to 2 minutes, or until softened. Add the sweet potatoes and cook, shaking the pan and flipping the potatoes occasionally for about 10 minutes, or until they are nicely brown and tender.

4.Season to taste with kosher salt and, if necessary, red pepper flakes. Serve hot.

MAKES 4 SERVINGS

DON’T KISS ME!

I first encountered sopa de ajo (garlic soup) in Mexico, where it was served still simmering in an earthenware cazuela with a raw egg dropped into it just before serving. I was amazed—and still am, now that I make it myself—that the many cloves of garlic cook down to such a different, mild flavor, very unlike the flavors of raw or sautéed garlic. How does simmering garlic in water “tame” it so much?

The same thing happens to garlic’s no-kissin’ cousin, the onion; French onion soup tastes nothing like raw or fried onions. It’s all in the different chemical reactions that take place at room temperature, at the wet temperature of boiling water, and at the high and dry temperature of frying.