I didn’t see it coming, that mild feeling of electric currents buzzing on my tongue as if I’d licked a battery.

Seated on a busy pavement in front of a lazy Susan weighed down with sizzling hotpot, diced rabbit and fish soup, I was digging into a spicy meal on the humid first night of a visit to Chengdu, the capital of China’s south-western Sichuan province and the cradle of the region’s famously fiery cuisine.

The plates resembled volcanic islands, each dish’s contents swimming in chilli oil hidden beneath a red-hot mountain of peppers and garlic. Tongue ablaze and face flushed, I felt a prickliness starting to numb my taste buds. The waiter chuckled at my glistening forehead and handed me a handkerchief; it was clear who at the table was the foreigner not yet acclimated to local flavours.

The tandem combination of burning and numbing from these two ingredients is known in Chinese as málà

Unsettling at first, that tingly feeling of electricity offered a pleasant reprieve from the heat. This curious effect was thanks to one of the most integral ingredients in this province’s distinctive cuisine: the tiny-but-mighty Sichuan peppercorn, a spice indigenous to China.

The seasoning’s English label is a misnomer, as the “peppercorns” are actually husks of dried berries from a type of prickly ash shrub. When you eat chillies, capsaicin induces a burning sensation known in Chinese as là. Sichuan peppercorns produce a phenomenon called paraesthesia, in which the lips and tongue feel as though they are vibrating and go vaguely numb – known as má. Together, the tandem combination of burning and numbing from these two ingredients is known in Chinese as málà, a hallmark of Sichuan cuisine that facilitates sweating – and thus creates a cooling effect that makes the sweltering climate more tolerable.

“The level of humidity in Sichuan can make you feel lethargic and uncomfortable,” said Cheng Yi, who owns the Cheng Big Mouth Frog restaurant, which specialises in Sichuan-style frog stew, in the nearby city of Chongqing. “Sichuan peppercorn not only adds fragrance but also helps combat dampness.”

Despite not feeling hungry at first, my stomach became a bottomless pit as I continued eating

According to Traditional Chinese Medicine, the human body’s constitutions are intimately connected with the surrounding environment. Highly humid weather, which Chengdu experiences year-round, is said to create dampness in the body, which can lead to headaches and bloating. Eating spicy food and sweating can mitigate the adverse physiological effects of humidity.

“We always joke that if you have a cold, just go eat a meal of potently málà food and you’ll recover,” Cheng quipped. “By eliminating toxins from the body through sweating, you’ll feel much better the next day.”

I indeed felt cooler as the meal wore on, despite sitting outside in the moist air. And despite not feeling hungry at first, my stomach became a bottomless pit as I continued eating; the Sichuan peppercorn was also soothing my mouth with its vaguely anaesthetic prickliness, enabling me to eat more by rendering the spice of the chillies a little less fiery.

“When it’s humid in the summer, your appetite isn’t as good. But stimulating flavours can spur you to eat more,” said Gan Siqi, a born-and-bred Chengdu native and avid cook.

The cuisine’s restorative effects seem to have given Sichuan food a reputation within China for being rather irresistible. Gan frequently cooks Sichuan dishes for out-of-town guests and has seen many unwittingly get hooked on the cuisine.

“When people first try Sichuan food, on one hand they will fear it – because they’re pouring sweat and their tongues go numb – but they will also want to eat it again,” said Gan.

The level of fragrance that you get in Sichuan food is unlike anything in the world

“As a foreigner, I wasn’t 100% convinced that hotpot was the best, or even that delicious. But I think it only took a few times, and I was hooked,” said Trevor James, who explores Sichuan street food for his blog and YouTube channel The Food Ranger.

James told me many people have the misconception that Sichuan food is one-dimensionally hot. After living in Chengdu for six years, he would describe the food as more aromatic than spicy. “The level of fragrance that you get in Sichuan food is unlike anything in the world,” he said.

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Much of that unique fragrance comes from Sichuan peppercorn. And while málà is one of the best-loved flavour profiles of the cuisine, the peppercorn’s aroma plays a part across different types of Sichuan dishes, not only the spicy ones. Chefs often use it to heighten other seasonings and concoct more balanced, harmonious flavour profiles. Simmering fresh Sichuan peppercorn in oil, for example, produces a vaguely numbing oil that can enhance noodles, salads and sauces. Grinding it into a powder makes an ideal addition to a dry rub for roasted meat. The spice’s ability to complement many different flavours partly explains how it became so ubiquitous in the region.

“Chongqing is a port city, and back in the day, a lot of workers did hard labour by the docks,” said Elaine Luo, a Chongqing native who runs the blog China Sichuan Food. “The wealthy people in Sichuan ate a lot of beef, but they saw the offal as unrefined, something to throw away. So, the labourers would take the offal for a source of protein.”

For those workers in Chongqing, which was part of Sichuan province until 1997, Sichuan peppercorn was a cheap way to mask the gamey taste of otherwise pungent meats. Today, famous dishes such as fūqī fèi piàn – thinly sliced beef offal tossed with chilli oil, Sichuan peppercorn and garlic – make star ingredients of those cuts once considered lower-class.

Dining habits are often necessitated by geography and circumstance, and only later evolve into distinct regional lifestyles. Sichuan’s food is now considered one of the Eight Great Cuisines of China – which are commonly recognised by Chinese chefs to be the best and most sophisticated cuisines in the country – and in 2010, Chengdu was the first Asian city to be designated a Unesco Creative City of Gastronomy.

Thanks to the growing Chinese diaspora and increasing cultural exchange, Sichuan cuisine is also one of the most celebrated regional Chinese cuisines overseas, with restaurants such as hotpot chain Haidilao recently launching dozens of international locations in the UK, North America, Australia and Asia. The cuisine’s popularity is especially impressive considering that the importation of Sichuan peppercorn to the United States was banned between 1968 and 2005 over concerns the spice may carry crop bacteria.

The importation of Sichuan peppercorn to the United States was banned between 1968 and 2005

Even today, finding fresh, potent Sichuan peppercorn overseas can be challenging; what I’ve purchased in the US lacks aroma and often comes with seeds and twigs. Taylor Holliday, founder of The Mala Market – a blog-turned-import specialist that sources Sichuan spices – says that often happens when the ingredient is processed by machine.

“[Machine-sorting of Sichuan peppercorn] leaves a lot of seeds, but that’s what most people will export because there’s no manual labour involved,” she said.

Over the years, Holliday has learned Sichuan peppercorn must be hand-sorted in order to leave only the husks. “It really does make a huge difference in the taste,” she said. “A carefully processed Sichuan peppercorn just tastes much more fragrant and [is] much more potent.”

If chefs can get their hands on it, fresh Sichuan peppercorn at its full potential may have myriad applications even beyond Sichuan cuisine. Nowadays, restaurants outside China have begun using the numbing ingredient in non-traditional ways. Beast & Butterflies in the M Social Singapore Hotel recently included it in a chocolate and banana sphere dessert. The Washington DC-area joint Hot Lola’s adds it to a variation on Nashville hot chicken. And in New York, Shelsky’s Brooklyn Bagels sprinkles it atop a Sichuan pepper bialy (a yeast roll that’s similar to a bagel).

“The world is a global village now. You can try some of what’s mine, I can try some of what’s yours. I think it’s great,” said Luo.

This means more people around the world can discover the ingredient’s powerful effects, which Sichuan locals say are both physiological and mental. Despite rapid development that has seen Chengdu taken over by skyscrapers in recent decades, the city has a decidedly carefree feel that noticeably contrasts with the fast-paced metropolises of Shanghai or Shenzhen. To some locals, Chengdu’s easy-going vibe can even be traced back to its gastronomy.

“Compared to people from other provinces, Sichuan folks pay more attention to quality of life. We believe, since we are alive today, we should live for the present,” said Luo. “Eating málà supports this mindset.”

It’s almost as if the powerful burn of spicy foods, coupled with the afterglow of peppercorns numbing away the pain, somehow makes málà food cathartic. Some dishes even derive their names from this belief: shāngxīn liángfěn, or “sad jelly noodles”, is said to be so named because the strong málà flavours will bring tears to your eyes. “If you’re sad, and you eat some of those jelly noodles, you won’t be sad anymore,” said Luo. “You’ll be dripping sweat and feel reinvigorated, as if you just vented any negative feelings.” One might say Sichuan’s málà flavour is the gastronomic encapsulation of life’s ebb and flow: alternating discomfort and contentment, taking turns to reign over the senses.

Back at home and craving Chengdu’s potent flavours, I thought about what Luo said as I tucked into a steaming bowl of mapo tofu (or “pock-marked grandmother’s tofu”, so named because it was first served by a Chengdu grandmother in the 1800s with smallpox scars. It’s a pungent dish of tofu and pork swirled with fermented broad bean paste, chillies and, of course, Sichuan peppercorn. The frenzy of flavours set off firecrackers on my tongue, quietened moments later by the welcome sensation of numbness. But, as I learned in Chengdu, there’s an addictive quality to that one-two punch. The chillies didn’t wait long before beckoning me for another bite.

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