What’s the big deal about chilli in Asia?

When we say a dish is “spicy”, we usually mean that it tastes “hot”. The term “spicy”, though, covers far more than that. It includes chillies, peppercorns, ginger, mustard, horseradish, and many other stimulating foods.

Chillies bring an unmistakable, “my mouth is burning” heat that many find delightful, if an ordeal at times”. What about the unassuming chilli sets our mouths aflame?

Chilli has a special something that other spices don’t: capsaicin. A chemical irritant, capsaicin bonds with the mouth’s temperature receptors, causing us to feel excessive heat. Other hot spices’ active components act differently. Just look at the mustard family—its more volatile substance wafts up the nose instead, as anyone who has felt wasabi’s nasal punch can attest.

Eaten on its own, a chilli’s “hotness” comes down to its capsaicin concentration, measured in terms of Scoville heat units (SHU). Although some have estimated other “hot spices” in SHU terms, their heat pales in comparison. Pepper’s and ginger’s pure components are estimated at 100,000 and 60,000 SHU, respectively, but pure capsaicin comes in at 16 million SHU.

Within chilli varieties, the range of heat is astounding. The world’s hottest verified pepper—the Carolina Reaper—is 24 times hotter than the mighty bird’s eye chilli, an iconic chilli in Asian cuisine.

Chillies are native to South America. They were most likely spread by Portuguese ships venturing eastwards to ancient crossroads like Goa, Malacca, and Siam. Arriving in the 1500s, chilli spread rapidly across Asia—evidence suggests that local botanical varieties, appearances in recipe books, and written records of its prevalence in Asian societies had started showing up by the 1600s.

This journey shows up even in language—“chilli” comes from the Aztecan Nahuatl word “xilli”. In China, chilli is now called lajiao (辣椒), but it was initially called fanjiao (番椒) and haijiao (海椒)—“foreign pepper” and “sea pepper”, respectively—hinting at its possible foreign and maritime trade origins. Similarly, chilli in the Tamil language (milagai) seems to have come after the word for peppercorns (milagu).

Although chillies reached Asia later than they did other regions, they spread in such a flash here that Europeans soon thought they were native to Asia.

Why, you may ask? Well, several possibilities exist.

Eating chilli makes you sweat, cooling you down in the tropical heat. Chillies also slow harmful bacteria from growing when food spoils, which happens more readily in humid regions. Historically, chillies were much cheaper and easier to grow than black pepper, leading Indian poet Purandara Dasa to call it “the saviour of the poor”. Even rice might play a part; many Asian meals revolve around rice, and chilli elevates its bland starchiness.

It is fairer to say, however, that there isn’t one conclusive reason. After all, salt was more effective as a food preservative back in the day. Chillies may have been cheap and easy to grow, but so are many other edible plants that are less widespread or popular.

Chilli is loved by people all over the world for all sorts of reasons. Perhaps the more interesting question, then, is how we appreciate chilli.

Why we love chilli may be universal, but how we appreciate chilli is local. Asian communities use and experience chilli in ways shaped by philosophical and culinary traditions—and this comes out clearly in how we pair chilli with other ingredients.

Although chillies have distinct flavours such as sweetness and fruitiness—a subtlety easily missed when your mouth is on fire—chilli’s overall experience is determined by what it’s paired with. We see this when unpacking common chilli sauces and condiments found in Asia.

Asia’s sheer diversity of sauces may seem overwhelming and random. But at a closer look, they’re organised by culinary principles based on gastronomy and health.

Let’s unpack the gastronomy first. Most cuisines strive to balance different tastes and flavours. Here, we’ve visualised the ingredients in 45 Asian chilli sauces to see how practice gels with theory.

Click the arrows to learn the key tastes and culinary principles around chilli! Explore each ingredient’s pairings on your own at the end.

Historically, food in some Asian societies has intertwined with notions of well-being, which are often more extensive than today’s views on nutritional value. These traditional beliefs examine how the nature of food ties in to bodily and spiritual health and the wider environment, and their influence can still be seen in many Asian cuisines.

According to the traditional Chinese Five Elements (Wu Xing) framework—which classifies the main five flavours using natural elements and the cosmic forces of yin and yang—chilli’s dry nature aids lung health and counterbalances foods associated with its concept of “internal dampness”. This belief might be why chilli shows up so much in Southwestern Chinese cuisines, where the humid climate is linked to dampness.

Like in gastronomy, the principle of balance can be found in some of these beliefs. Similar ideas of balancing different natures in food can be seen in other culinary cultures, such as Ayurveda in South Asia.

Shared by many food cultures in Asia, these health and gastronomy principles have been shaped by local landscapes both physical and culinary.

Before chilli arrived in Asia, Korean cuisine had long emphasised fermentation, and Japan’s Shinto-influenced Washoku culinary philosophy favoured accentuating the natural flavours of ingredients. This may explain why chilli in Korea’s iconic chilli sauce (gochujang) is fermented, and why Japanese condiments tend to use less chilli (e.g., shichimi togarashi and yuzu koshō).

It seems that chilli has merged into culinary traditions rather than revolutionised them. Chilli’s many stories speak to the resilience and creativity of communities across Asia, who continue to transform and elevate this ingredient in their kitchens.

If all food is a drama, chilli may just be the diva. Its unabashed sharpness dominates the spotlight and draws adoring fans—although it can also work well with other members of the flavour cast.

Asia went from having no chillies at all to becoming its biggest producer in just five centuries. Our red-hot love affair with the chilli pepper is indeed a tale for the ages.