Although Amal Naj was born into a household that threw hot peppers into every dish, he grew up avoiding them. It was only when he went away to school in Northern Ireland that he developed a longing for the pepper’s “venom,” a longing that would later grow into the obsession that fueled this fascinating book.

PEPPERS appears at an ideal time to capitalize on America’s love affair with the pungent and often fiery fruit. More and more of us are sampling peppers for the first time, and those in the know are hungering for ever hotter ones. According to the NEW YORK TIMES, total U.S. sales of salsa recently topped those of ketchup for the first time.

Naj reminds us that we are merely catching up with the rest of the world. The United Nations recognizes 1,600 varieties of hot peppers, ranging from the tiny red piquin to the long green Big Jim, which has made the GUINNESS BOOK OF RECORDS at thirteen-and-a-half inches. In between come varieties of all shapes, sizes, colors, and—hence the appeal of Naj’s book— intensities.

So great is the range of hotness among peppers that a special scale, developed by pharmacist Wilbur Scoville, is used to measure them. At the zero end of the scale is our bell pepper; at the other, at an incredible 350,000 Scoville units, lies the Mayan habanero, the first experience of which leaves Naj slightly deaf for several hours. Why do we crave something that hurts so much? Naj favors the explanation that capsaicin, the active chemical in hot peppers, tricks the body into releasing pain-killing endorphins, creating a natural and harmless “high.”

Along the way Naj discusses the complicated history of McIlhenny Company, whose famous Tabasco Pepper Sauce measures a mere 40,000 Scoville units. And perhaps most interestingly of all, he accompanies a botanist to Bolivia in search of the elusive “mother pepper,” the ancestral plant from which our rich harvest of piquins and Big Jims and habaneros has sprung.