Chili peppers are losing their heat as the world gets warmer

Illustration: Maggie Cowles for Bloomberg

For three generations, Ken Koh's family has bought a specific variety of chili peppers from the same Southeast Asian supplier to make its bestselling sauces.

A team of four chops, blends and cooks the peppers at a modest three-story factory in Singapore. Inside, a sign written in Chinese characters plays on a popular idiom: "Food is the life of people, sauce is the life of food."

But last quarter Koh was forced to cut production of his chili sauces by 25%. He's struggling to restock local supermarket outlets and his company Nanyang Sauce had to discontinue a special gift set of three chili sauces, named the "Spice of Life."

The culprit? Climate change. Extreme weather across major chili planting regions this year has disrupted supply, pushed up prices and, worst of all, made the peppers taste milder.

Scientists say it's not a one-off, but a long-term trend that's impacting other foodstuffs as well: Coffee blends are growing more bitter and coconuts more bland due to erratic rainfall, while rising temperatures are impacting the quality and quantity of Napa cabbage, the key ingredient of the beloved Korean dish kimchi.

"Enjoy your chili while it lasts because we don't know when it'll be gone," said Koh, 40, shaking his head in exasperation.

Chilis are the berries or fruits of plants from the genus Capsicum and are used as a spice in cuisines all over the world. There are an estimated 4,000 varieties, including jalapeño, habanero and bird's eye, ranging in color, size and heat.

From the peppers grown by small farmers in Mexico and India to those for giant producers such as California-based Huy Fong Foods Inc., which makes the famous Sriracha hot sauce, the chili trade is worth an estimated $9 billion a year, according to the Food and Agriculture Organization of the United Nations. Asia accounts for almost 70% of global chili supply, FAO data show.

A chili's pungency is derived from a group of heat-producing alkaloids including capsaicin in the fruit, with hotter, drier conditions typically increasing spiciness. The perfect growing conditions are becoming harder to find as climate change increases the frequency of weather extremes such as drought and floods and intensifies rainfall.

"As the crop absorbs a lot of this extra moisture, it puts it in the flesh of the fruit of the chili pepper," said Kraig Kraft, 46, an Oregon-based agroecologist and co-author of Chasing Chiles, which examines global warming's impact on the crop. "All of a sudden, the pungency becomes diluted."

Drought and extreme heat can also stress young plants, preventing a crop from even blossoming. A severe drought in Mexico this year caused a shortage of red winter jalapeños, forcing Huy Fong Foods to halt production in May, the Washington Post reported.

Chilis are "very sensitive to any changes in the weather," said Karma Bhutia, 37, a scientist at the Dr. Rajendra Prasad Central Agricultural University in India who has researched the impact of climate change on the growth and development of chili plants. Chilis typically thrive in temperatures between 25C and 30C (77F and 86F), he said.

Unpredictable weather has been a curse for farmers like Srinath Arumugam, 29, in northwest Malaysia. His first order of business during planting season is to check the weather forecast. The next is to pray for a sunny day. Torrential rain can wash away the fertilizer needed to sustain his two acres of chili crops.

"Our fertilizer will be wasted, and we'll have to do it all over again the next day" at a cost of 14,400 ringgit ($3,234), he said. "We used to be able to predict the weather, but now we can't."

It's a similar story in parts of China, the world's largest chili producer, where a summer of typhoons and flooding has impacted crops. Monthly wholesale prices for red chilis hit a two-year high in October, data from Beijing agricultural market Xinfadi show.

Scientists are creating new varieties of chilis that are more resistant to climate change and disease. Yet the challenge lies in retaining the same flavors.

"It sounds terrible, but once these peppers are gone, you cannot recreate their original taste," said Jorge Berny, 44, an agronomist who is working with farmers in Yucatan, Mexico, on producing indigenous and commercial varieties of chili. "You can replace them with something else, but it's not the same."

Commercial kitchens are having to adapt to the changing flavors.

Daniel Sia, executive chef of Singapore-based The Coconut Club, buys as much as 20% more stock of chili peppers now versus a few years ago to make up for the lower heat.

"Sometimes you need to add a little bit more chili, sometimes you need to change the blend," said Sia, whose signature dish of fragrant rice cooked in coconut milk and pandan leaf — nasi lemak — features a chili paste called sambal. "It all comes down to adjusting the taste to what it is supposed to be."

At nearby Thai restaurant Un-Yang-Kor-Dai, head chef Chitsanucha Tanawong, 42, said it isn't as simple as increasing the amount of chilis in a dish — sometimes she combines different chilis to get the desired heat.

"I must mix the chilis," Tanawong said, gesturing to a bowl of clear tom yum, a type of hot and sour soup made with lemongrass, tomatoes and, in this case, prawns. "If not, this whole bowl will be covered with only chopped chilis."

The restaurant, recognized with a Michelin Bib Gourmand award for good quality, good value cooking, is now paying at least S$1 (75 US cents) more for every kilogram of hot pepper from Thailand due to the recent flash floods.

Ultimately, chefs will be forced to innovate and find workarounds as climate change impacts the flavors of food, said Chasing Chiles co-author Kraft. But that deep cultural connection with a cuisine, or taste of place, is at risk.

"When you're looking at something like chilis and its food traditions, the taste of place is so dependent on one spice," he said. "If its availability is limited, it's not like you can just go and substitute with something else to replicate the same taste."

For Tamara Chavez, a Mexican chef based in Singapore, chilis are more than an ingredient. They are a way of life.

"When you eat a chili, you start to feel the heat in your lips, and then you start to sweat, and you feel warm in your body," said Chavez, 34, who co-owns Canchita Peruvian Cuisine and Spanish restaurant Tinto with her husband, Daniel. "But this morning, I ate six chili padis and felt nothing."