The argument of which chile pepper variety packs the most heat has been waging on for decades if not centuries.

It is said that Spanish explorers, after discovering the intensity of the flavor and spice of the American chile, became obsessed with finding the hottest varieties to take back with them to the Old World, a sort of contest of discovery to see who could achieve the greatest notoriety. By the time the Spanish arrived, chile cultivation had become an art with the indigenous Americans. But the contest to produce the hottest chile pepper continues in modern times.

Why? Perhaps because capsaicin, the active ingredient that puts the fire in the belly, has been touted for its curative powers for muscle aches as well as arthritis, headaches, and the common cold. Dieters are enthusiastically incorporating peppers into their regimen as they are said to raise the metabolism, thus helping burn off excess fat. Researchers are still studying the curative powers of capsaicin on some lung and stomach cancers.

But what was hot to the Spanish explorers can now be considered ‘mild’. Capsaicin is concentrated in the veins of the fruit and stimulates the nerve endings in your mouth, fooling your brain into thinking you're in pain. The brain responds by releasing substances called endorphins, which are similar in structure to morphine. A mild euphoria results, and chilies can be mildly addictive because of this hot pepper "high".Chile hotness is rated in Scoville units. One of the hottest peppers on record was the Habañero/Scotch bonnet, which some claim are the same pepper and others claim are slightly different varieties. Habañeros are rated at 100,000 to 350,000 Scoville units. By contrast, the lowly Serrano comes in at about 5,000 to 15,000 Scoville units.

The habañero is a brilliant yellow and orange fruit, resembling a somewhat squashed miniature bell. Habañeros will send a hard core pepper enthusiast into raptures. It has a subtle, apricot-like, taste followed by a heat explosion. Even pepper sauce contests have been known to ban pure habañero salsas from public tastings due to their excessive fiery taste.

But even the spicy habañero chile pales in comparison to the new world leader in the’ hot department’.

A few years back scientists introduced the Red Savina Habanero chile - a nuclear chile that can melt the socks off your feet. But now even those have been replaced in the hottest chile department.

Researchers at New Mexico State University recently discovered what they are calling, by far, the world’s hottest chile pepper.
Bhut Jolokia, a variety of chile pepper originating in Assam, India, has earned Guiness World Records’ recognition as the world’s hottest chile pepper by blasting past the previous champion Red Savina. In replicated tests of Scoville heat units (SHUs), Bhut Jolokia reached one million SHUs, almost double the SHUs of Red Savina, which measured a mere 577,000.

Dr. Paul Bosland, Director of the Chile Pepper Institute at New Mexico State University’s Department of Plant and Environmental Sciences collected seeds of Bhut Jolokia while visiting India in 2001. Bosland grew Bhut Jolokia plants under insect-proof cages for three years to produce enough seed to complete the required field tests.

“The name Bhut Jolokia translates as ‘ghost chile,’” Bosland said, “I think it’s because the chile is so hot, you give up the ghost when you eat it!” Bosland added that the intense heat concentration of Bhut Jolokia could have significant impact on the food industry as an economical seasoning in packaged foods.

Like the Habanero, Scotch Bonnet and Red Savina, Bhut Jolokia belongs to the Capsicum chinense family. This landrace chile originated in the Northeast of India, particularly Assam, Nagaland, Manipur and neighboring Bangladesh. Other names for this chile include Nagahari, Naga Jolokia, Bih Jolokia, Borbih, Raja Mircha, Raja Chilli, Mirch, Mircha, Naga Moresh, Naga Morich, Tezpur, and quite recently Dorset Naga.(with possible slight differences). In their home country, Bhut Jolokia and Bih Jolokia are also spelled Bhwt Jolokiya and Bih Jolkiya respectively.

For many years, there was uncertainty about this particular chile pepper, some sources even listed cayenne-type peppers as Naga Jolokia or put it into the C. frutescens species. Eventually a field trial with comprehensive analysis by the NMSU Chile Pepper Institute (CPI) shed light on this cultivar.

Both Assamese growers and the Chile Pepper Institute found top heat levels around one million Scoville Heat Units (SHU), and the Chile Pepper Institute's findings for Bhut Jolokia were even awarded the world record  as the "hottest of all spices" by Guinness World Records

The complete study and abstract are available on the ASHS HortScience electronic journal web site: http://hortsci.ashspublications.org/cgi/content/abstract/42/2/222.

THE CHILE HEAT SCALE
The Scoville Units
* Red Savina Habañero 350-550,000
Scoville Heat Units
* Habañero (Scotch Bonnet) 200-300,000 Scoville Heat Units
* Thai 70-80,000 Scoville Heat Units
* Chiltecpin 70-80,000 Scoville Heat Units
* Santaka 50-60,000 Scoville Heat Units * Tabasco 30-50,000 Scoville Heat Units * Chilipiquin 30-40,000 Scoville Heat Units
* Cayenne 35-40,000 Scoville Heat Units * Serrano 7-25,000 Scoville Heat Units * Chile de Arbol 15-30,000 Scoville Heat Units
* Jalapeño 3.5-4,500 Scoville Heat Units * Ancho Poblano 2.5-3,000 Scoville Heat Units
* Anaheim 1-1,500 Scoville Heat Units * Bell Pepper 0 Scoville Heat Units