'It feels like your mouth is on fire, but afterwards it makes you smile'

Carlos Carvajal is known as Doctor Salsas. And, when he has to explain what he does, he says he is a spicy revolutionary. With an American father and a Spanish mother from Granada, he has spent years cultivating fearsome chilli pepper varieties in Andalucía and making sauces as delicious as they are deadly, which he markets through the brands Doctor Salsas and Sierra Nevada.

If tabasco is between 2,000 and 5,000 Scoville units (the scientific measure of the pungency of chillies), his Salsa del Infierno has 415,000, although he also sells a capsaicin extract that reaches an inconceivable nine million.

"Just one drop can make you remember it for hours," he warns.

How did you discover spicy food?

With my mother being Spanish and in California we didn't eat spicy food. The first time was in the military, in Missouri, in a place where it was very hot and there were a lot of bugs. They used to put tabasco on the table and I tried it: it burned me, but at the same time endorphins started running through my head and I liked the sensation. From then on I became addicted to chillies.

And what is the reason for going to the extreme?

I have old cars that go very fast, I have practised martial arts for 40 years, I do a lot of surfing.... I think it's a bit along those lines of enjoying strong sensations and emotions.

In Spain people are a little bit reluctant to try spicy foods, aren't they?

For many years hot spicy foods have been 'in the closet', there's never been much availability and it was all about burning the mouth, not looking for flavours and sensations. In recent years though, it has become a trend, as it was in the 1990s in the United States, although here it is still in its infancy.

But traditional Spanish cuisine is not very spicy.

There are some foods: the 'piparrak' from the north, the 'alegrías' from La Rioja.... Also the Arab influence in Andalucía has a certain spiciness.

Which country's cuisine is king in this field?

Indian and Asian in general, they seem to have a very high tolerance! In Mexico spicy food is not as hot as it is in India, China or Thailand... It's something to do with the temperature, spicy foods make you sweat and that cools the body. That's why hot countries eat a lot of spicy food in summer. Besides, when there isn't much money and you eat beans with rice every day, you can cook them in fifteen thousand different ways using varieties of dried chilli peppers: in Mexico they are the kings of doing that.

You have written that when you came to Spain you thought the spicy products were "bad".

That's because there wasn't much choice, tabasco and not much else. I came to visit my mother and would find industrial produced sauces but nowadays there are companies in Almeria and Barcelona that are making really flavourful spices. There are still manufacturers though, who see the money, and turn out tasteless sauces without soul, as you'll find everywhere.

What does a sauce have to have, besides heat, to be good?

Natural ingredients, preferably local and in season. You can be quite creative. We've just made a sauce from Canary bananas and fermented South American chillies... It turned out very good! Fruit and spicy heat go well together: in Mexico it's usual to eat fruit with a mixture of spices. Mango, custard apple and peach give a special touch to sauces.

The anti-spicy brigade always says it masks the flavour of the food...

Not at all! A little heat enhances the flavour, like any spice.

Is there anything you don't add chilli to?

Well, I don't put it on Iberian ham.

You grow the Carolina Reaper, which has a terrible reputation. What's it like to bite into one?

Absolutely brutal, you feel your mouth on fire, then your throat and finally the capsaicin hits your stomach. It can give you 'cramps', period-like pains, but also endorphins, so you'll be laughing after the pain. I don't bite into them anymore, a jalapeño is the hottest I'll eat raw.

Which is the hottest dish you have tried?

At a party, with some biker friends who were a little crazy, they decided to have a contest: we ate chicken wings coated with dried, mashed Carolina Reaper and nine million extract. I competed with the guys and thought I was going to have a baby, because of the fight that started in my stomach.

Did you win?

I let them win.