Feel like turning up the heat? Check out this article I did for Cravings magazine on the science of chillies.

They send your body wild and keep you warm at night. They leave you red-faced and panting. They’re chillies, and they’re red hot.

Spicing it up

Munch down on a chilli and you’ll do more than cause a meltdown in your mouth. Chillies can boost your metabolism, control your cholesterol, reduce fat deposits, and lower your blood pressure. And they taste great too.

Turning up the heat is a natural chemical called capsaicin, which works by aggravating pain sensors in your mouth. The pain sends your entire body into overdrive, opening blood vessels, increasing blood flow, and flooding your system with endorphins.

Endorphins are your body’s natural painkillers and are also associated with that feeling of pleasure after orgasm. Regular chilli-eaters become addicted to the endorphin release, but must eat spicier chillies to trigger the rush.

Hot for health

Chillies have twice the vitamin C of citrus fruits, and also contain vitamin A, vitamins B1, B2 and B3, beta-carotene, folic acid and potassium. Studies have shown that capsaicin reduces the amount of fat stored in the blood cells, reduces fat deposits in the liver, and helps you burn more calories after a meal.

Chillies have been used to treat coughs, colds, asthma and laryngitis, and creams containing capsaicin have been reported to reduce the pain associated with shingles, arthritis, and diabetic neuropathy.

Yale University School of Medicine has even devised a chilli candy to help ease mouth pain in cancer patients. There are also reports that eating chillies can assist with cold sores, cold feet, nosebleeds and varicose veins.

Turning up the heat

Not all chillies are created equal.

In 1912 a chemist named Wilbur Scoville invented a way to determine just how hot different chillis could be. The test involved a panel of tasters sipping sugared chilli juice until their tongues stopped burning. The unit for chilli spiciness, the Scoville unit, was named after this brave chap.

How hot? Ordinary capsicums rate a lacklustre zero; Jalapenos hit you with around five thousand Scoville units; Cayennes are around ten times hotter than Jalapenos, and Habaneros provide up to 350,000 Scoville units of fun. To put this in perspective, one teaspoon of Habanero chilli should be mixed with 1.75 litres of sugar water for you to avoid its heat.

Did you know? Capsaicin is used in pepper sprays, which rate around two million Scoville units. The hottest chilli in the word is rumoured to be India’s Naga Jolokia, at a fiery 855,000 Scoville units.

Hot tip: Reduce firepower by removing chilli seeds and the veins that attach them to the chilli pod.

Cooking with chillies

Beware! Chillis may put a love-buzz on your tongue, but they cause deep regret when near your eyes. Always wash your hands, chopping boards, knives, and immediate vicinity after handling chillis.

Hot tip: Need protection? Wear gloves or coat your hands with cooking oil before handling chillis.

Overdosing on chillis won’t kill you, but if the pain is all too much, try a nice glass of red. Capsaicin will wash away in fats, oils or alcohol. A glass of iced water won’t make any difference because capsaicin won’t dissolve in water.

The seeds of love

Want to grow your own? The secret is a good soil: “Lots of sheep and cow manure,” says chilli connoisseur Claude Micale of Herbs R Us. “Also full sun, a weekly feed of seaweed solution, and an organic fertilizer…high potash will help them fruit more”.

“Chillis need to be outdoors, especially in our climate, and they won’t grow through winter. You can pick them while they’re green, or wait till they go red. If you pick them regularly they’ll flower and fruit through spring, summer and autumn.”

“I’m not a hot chilli person so I go for the anchos and the anaheims. Big Jim is an Anaheim-type chilli that grows about a foot long and 3-4 inches wide, excellent for stuffing and then roasting.”

Claude’s chilli tip: “Leave chillies in the sun until they’re crunchy dry, then put them in a bag and roll them with a rolling pin. You can also put them in a coffee grinder or food processor; it’s better a bit coarse than too powdery.”

What to look for

There’s more to chillies than heat. Start to explore the sunny colours and sparkling flavours, and you’ll find a whole garden of tastes just gasping to get on the plate.

Fresh chillies should have a shiny smooth skin; dried chillies should be flexible enough to bend without breaking.

Scrumptious chillies to look out for include:

• Anchos: Just a whisper of heat and a sweet mellow flavour, these chillies are great in mole sauces to add body and texture.
• Anaheims: Large, mild, and perfect for stuffing or roasting, they make delicious stews and sauces; usually eaten green.
• Arbols: Add some zing by popping one of these punchy numbers into an entire soup or stew; don’t forget to remove before serving.
• Birds Eyes: Great in Thai and Asian cooking; super-hot so use sparingly.
• Black Princes: Some say these look too good to eat; black fruits that mature to red with a mild, crisp flavour.
• Cayenne peppers: Hot, sweet and best eaten red, they are great in Hungarian and Mexican cuisine, or can be used whole in Szechwan cooking.
• Habaneros: Proceed with caution, these may be the world’s hottest chillies; best fresh rather than dried.
• Jalapenos: Small, fleshy and packed with attitude, these old favourites are great raw in salsas or salads, or cooked in sauces and soups.
• Serranos: Similar to Jalapenos but with more bite, these meaty chillies also suit salads and salsas, and are also delicious when roasted.

Hot cooking tips: Oven roasted chillis are easier to peel if you leave them to cool in a closed bag for ten minutes after roasting. Peel from the tip to the stem. Escape any threat of exploding chillis by stabbing a small hole into the side of each chilli before roasting.