The Life-Affirming Properties of Sichuan Pepper

The mouth-numbing spice — more popular than ever in the West — remind us why we seek out unfamiliar tastes.

· Hydroxy-alpha sanshool, an alkylamide that, instead of binding to taste receptors — as do compounds that trigger the reactions we identify as sour, salty, bitter and sweet — activates nerves primed to detect physical touch.

IT BEGINS WITH a hum. More precisely, you find yourself humming, only not of your own volition or making any sound. At first it’s faint, little micro-oscillations along the edges of the tongue, as if your mouth were a rung bell. Then, depending on the purity of what you’ve eaten and how much, it builds. People often describe the experience as numbing, but numbness is the loss of sensation, and this is the opposite: You are suddenly aware of your tongue’s every pore, of this strange landscape that is the tongue, an entire world within you. If you have eaten enough, you feel your lips balloon, except they don’t; nothing is happening that would be visible to the outside eye. If you speak, you’ll lisp. It’s as if you were being kissed by a horde of tiny bees.

Such is the effect of ingesting liberal amounts of hydroxy-alpha sanshool, an alkylamide that, instead of binding to taste receptors — as do compounds that trigger the reactions we identify as sour, salty, bitter and sweet — activates nerves primed to detect physical touch. Hydroxy-alpha sanshool abounds in plants of the genus Zanthoxylum, most famously those indigenous to China whose fruits are known in Mandarin as hua jiao and in English as Sichuan pepper. Zanthoxylum species with differing concentrations of the alkylamide grow around the world. In Japan, Korea, Nepal and parts of Laos, Thailand, India and Indonesia, their dried husks may be used to give a dish fragrance and floral, woodsy or sunny-sour undertones, along with a gentle twinge. But only in the southwestern Chinese provinces of Sichuan, Yunnan and Guizhou are the plants exploited to their maximum potential and essential to the cuisine. (So distinctive and singular is the buzz of Sichuan food that the wholly unrelated but similarly stimulating South American herb jambu has been called Sichuan buttons.)

Hua jiao is still something of a novelty in the West, its pleasures disorienting. As an ingredient, it has no real precedent in Western cooking. (Cloves, a key ingredient in many versions of chai and the perplexingly ubiquitous blend known as pumpkin spice, have the capacity to numb, but only in overwhelming, bitter quantities.) In 2020, Yao Zhao, a clean-energy consultant at the World Bank in Washington, D.C., and a native of Chongqing, a Chinese city that until 1997 was part of Sichuan, started selling Sichuan pepper oils through 50Hertz Tingly Foods, a company he co-founded with Lois Goh. He quickly realized that his biggest marketing challenge was explaining the tingle, or “ma” in Chinese. “If you’re not used to it, you might think it’s an allergy,” he says. The chef Simone Tong, who was born in Chengdu, Sichuan’s capital, ran the acclaimed Little Tong Noodle Shop in New York from 2017 to 2020, where diners sometimes expressed concern that they had food poisoning. “ ‘Is this magic mushrooms?’ ” she remembers one asking. “They couldn’t feel their tongues.” (She now owns Zoé Tong in Austin, Texas, with her husband and fellow chef, Matthew Hyland.) Travis Post, the chef of Plenty of Clouds in Seattle, which opened in 2018 featuring food from Sichuan and Yunnan, once had a panicked guest call the health department.

The problem isn’t lack of familiarity with Chinese food, which in the United States has attracted non-Chinese diners since the 1850s, when California Gold Rush miners in San Francisco bought cheap meal tickets at sprawling Chinese eating houses that could seat hundreds at once, as the historian Haiming Liu recounts in “From Canton Restaurant to Panda Express” (2015). Almost all early Chinese immigrants to the United States had roots in the southeastern coastal province of Guangdong — whose capital’s name was Anglicized as Canton — and so for decades what most Americans knew as Chinese food was Cantonese, a cuisine that prizes subtlety over sensation. Immigration reform and the abolition of country of origin quotas in 1965 brought new arrivals from other regions of China with their own culinary traditions.

HOW EASILY LANGUAGE leads us astray. Sichuan pepper isn’t a pepper. No relation to either black pepper (genus Piper, family Piperaceae) or chile (genus Capsicum, family Solanaceae) — which in turn bear no relation to each other — it belongs to Rutaceae, the citrus family. Further, the part of the plant used in cooking is not the whole berry, as with black pepper, but the husk, with the seeds shaken out. Is the English name a matter of confusion or willful obfuscation? Black pepper, used in India for at least 3,000 years, was exalted as a luxury in the Roman Empire, “bought by weight like gold or silver,” as the historian Pliny the Elder chronicled in the first century A.D. The value of the spice had scarcely lessened by the time Christopher Columbus stumbled across chiles in the Caribbean in 1493, so it was likely a strategic decision to call the fierce chile “pimiento,” casting it as a masculine counterpart to — and commercial competitor for — black pepper’s milder “pimienta,” as the French sociologist Maguelonne Toussaint-Samat notes in “A History of Food” (1987). (Piperine, in black pepper, and capsaicin, in chiles, are both alkaloids that trip the same touch receptors, although capsaicin is much stronger.)

If the word “pepper” bears an aura of fiery heat — despite the lack thereof in the more humdrum, capsaicinless Capsicum cousins, bell peppers — how did it come to apply to the mysterious tickle-purr of hua jiao, which almost cools rather than sears? (Zhao likens it to Pop Rocks: “It doesn’t hurt you or burn you. It’s playful.”)

In this way words shift, drift, slip their moorings. Say the word “spicy” today and people think “hot.” But in ancient Greek, spice or seasoning was “aroma,” a substance that gave off a scent. In Late Latin, “species” was the term, denoting “special wares.” (Almost all the spices in the Western culinary canon come from plants with origins outside of Europe and, as a result, for centuries were costly imports reserved for the rich.) When the English term “spice” emerged around the 13th century, Columbus hadn’t yet crossed the Atlantic and encountered the chile.

Likewise in China: The British cookbook author and culinary scholar Fuchsia Dunlop, who was the first foreigner to enroll at the Sichuan Higher Institute of Cuisine, tells me that, long before the chile’s arrival on the country’s eastern coast in the 16th century, the word for “spicy” was “xin,” ranked alongside sour, salty, bitter and sweet in the classical system of flavors and applied to the likes of garlic, ginger and hua jiao. But as the American historian Brian R. Dott recounts in “The Chile Pepper in China” (2020), the chile, although late to southwestern China — its first recorded appearance in Sichuan wasn’t until 1749 — proved so cheap and easy to grow that it soon displaced hua jiao as a daily seasoning, “even shifting the very meaning of spicy.” A new term was required, “la,” or “hot,” giving rise to what would become a defining signature of Sichuan cuisine, the grand theater known as ma la: the marriage of Sichuan pepper, with its rippling electricity (ma), and the ferocious heat (la) of chiles, often deployed by the fistful.

According to Zhao, a dentist in China might traditionally give a patient a handful of Sichuan pepper to ease suffering during surgery or from a toothache. “Ma” is the root in the Chinese word for anesthesia, “ma zui” — but also, historically, the name for cannabis (today “da ma”), itself long used as a painkiller in both the East and West; a Chinese compendium of pharmacological remedies, compiled during the later Han dynasty but attributed to the mythical Emperor Shennong from the 28th century B.C., cautions that “taking much of it may make one behold ghosts and frenetically run about.” Is there a through line from numbness to communing with the spirit world? Since the first public demonstration of the use of ether in 1846, in the surgical amphitheater of Massachusetts General Hospital in Boston, anesthesia has promised revelation, as the journalist Dan Piepenbring recounted earlier this year in The Baffler. For early practitioners, the muting of feeling created an altered state, akin to the experience of modern-day dissociatives like ketamine, synthesized in the 1960s for use on the operating table and now more commonly taken in nightclubs — a “gossamer untethering of body and brain,” he writes, in which one’s accustomed nervous responses were halted, allowing for a glimpse of “new textures beyond reality.”