Both the ghost pepper and the habanero have topped the Guinness Book of World Record charts for the world's hottest pepper. Although that honor has also been held by the Trinidad Scorpion Butch T pepper, ghost peppers and habaneros are still scorchingly hot. In fact, one is hot enough that the Indian government uses it to make hand grenades.
Behind the Heat
The heat of peppers comes from capsaicin. Capsaicin is an alkaloid produced by the peppers' placenta and plant walls. It is only found in chili peppers. When you eat peppers that contain capsaicin, it triggers pain receptors in the mouth and digestive tract. The body, in response, releases endorphins, which may explain some of chili peppers' attraction. The hottest chilies, however, contain no pleasure for even the most-intrepid chili eater. These peppers are so hot they are dangerous.
Habanero peppers are members of the chinense species of Capsicum, or chili, genus. They come in several varieties. Some are orange or red; others are brown, white or pink. The hottest habanero, the Red Savina pepper, is deep red. Habanero peppers may have originated in Cuba and from there were brought to the Yucatan in Mexico. The Yucatan is the largest pepper-growing region in the world. Habaneros, though searingly hot, are used in moderation in cooking.
Ghastly Ghost Peppers
Ghost peppers are so hot that they are rarely used in cooking. Instead, the Indian government has considered producing ghost-pepper hand grenades. These peppers, also called Bhut Jolokia, are probably a hybrid of two unknown varieties of the Chinese species of peppers. Originally from India, ghost peppers are now being cultivated in New Mexico and at Cal Poly Pomona, where they bear the warning sign "Handle at your own risk!!"
The heat of peppers is measured in Scoville units. Pure capsaicin, which is not naturally occurring and can only be produced in the lab, rates roughly 16,000,000 on the Scoville scale. The common jalapeño contains about 2,500 to 8,000 Scoville units of heat. Common habaneros, the yellow and orange varieties, contain 150,000 to 325,000 units. The Red Savina habanero tops out at 350,000 to 580,000 units. Yet these tongue scorchers are considerably milder than the ghost pepper, which routinely tops 1 million Scoville units.