Too much heat, too little spice: How India's chillies are losing their fire

India's priced chillies are known for more than their heat. As weather patterns change, the conditions that give these peppers their distinctive character are under pressure.

In Short

• India's rare chillies are vital to regional cuisines and farmers' incomes
• Temperatures above 43-45°C harm chilli plants, reducing pungency
• Speciality chillies like Bhut Jolokia and Dalle Khursani face declining heat

India's rarest chillies are valued and loved for heat, flavour and smell. And that love is reason that they are an essential item on millions of plates across the country.

What's more is that neither of these characteristics can be replicated.

From Assam's Bhut Jolokia to Sikkim's Dalle Khursani and Nagaland's Naga King Chilli, these peppers are more than ingredients but are also part of regional food cultures and, for many farmers, valuable cash crops.

But the conditions that help produce these distinctive chillies are changing.

On this week's Climate On My Plate, a series by India Today Science, we explore the slow demise of India's beloved chillies and the heat they bring to the table.

Rising temperatures, erratic rainfall and more frequent weather extremes are putting increasing pressure on chilli plants, so much so that the heat stress is already affecting both the quantity and quality of the crop.

HOW DOES HEAT HARMS CHILLIES?

Chillies are warm-weather crops, but there is a limit to how much heat they can tolerate.

Research published in 2026 revealed that temperatures above about 43-45°C can severely affect chilli plants, particularly during reproductive stages when flowers and fruits are developing.

Heat stress can reduce growth and yields and can also affect compounds linked to colour, flavour and pungency.

That matters particularly for India's speciality varieties, whose value often lies in their distinctive characteristics.

Bhut Jolokia, grown mainly across Assam and other parts of Northeast India, is a case in point. It was recognised by Guinness World Records as the world's hottest chilli in 2007 and remains one of the world's hottest peppers, with its pungency exceeding one million Scoville Heat Units in some measurements.

But the chilli's famous heat is not fixed.

Temperature, rainfall and soil conditions can influence pungency, while poor-quality seeds, cultivation practices and environmental stress can also affect the crop.

Farmers and experts in Assam have been concerned about declining heat and aroma in some Bhut Jolokia crops since 2024.

CLIMATE CHANGE IS HITTING WHAT MAKES CHILLIES SPECIAL

The concern, therefore, is not simply that extreme heat could kill chilli plants.

It is that changing growing conditions could gradually alter the characteristics that make individual varieties valuable.

Sikkim's Dalle Khursani offers another example.

The small, round chilli is a prized cash crop of the state and is also grown in the Darjeeling hills. It is known for its intense pungency and has a Geographical Indication tag.

Previous studies have found substantial variation in capsaicin concentration among Dalle Khursani plants collected from different altitudes, with measured pungency ranging from about 3,05,000 to 4,57,000 Scoville Heat Units.

That natural variation is important because it shows how strongly a chilly's characteristics can differ across growing environments.

Climate change adds another layer of uncertainty.

As temperatures rise and rainfall becomes less predictable, farmers have to contend with greater stress during crucial stages of plant growth.

Heat can affect flowering and fruit development, while excessive moisture can increase disease pressure.

Researchers are therefore calling for more climate-resilient chilli varieties and cultivation practices.

THREAT TO FLAVOUR AND FARMERS

The stakes extend beyond how hot a chilli tastes.

Northeast India is a reservoir of distinctive agricultural varieties.

ICAR lists Dalle Khursani, Naga Mircha and other speciality chillies among the region's GI-registered crops, reflecting their cultural and commercial importance.

If climate stress makes cultivation more difficult, farmers could increasingly shift towards varieties that are easier to grow or more commercially reliable.

That could put additional pressure on the genetic diversity they contain.

For consumers, the eventual consequence may be that the chilli on the plate may still look the same, but its heat, aroma, flavour or price could change.

Climate change, in other words, is not merely threatening India's chillies, but is conspiring to change what makes India's hottest chillies so valuable in the first place.

- Ends