Let’s delve into some botany. You may have noticed in our photo, our habanero seedlings have wide, round leaves that differ from the more elongated, pointy leaves of bell peppers and jalapenos. That’s because the habanero, along with the Ghost, the Scorpion, and the Scotch Bonnet, are all members of the Capsicum chinense species. Bell peppers, cayenne peppers, and jalapenos, on the other hand, belong to the ‎Capsicum annuum species. Both species are frost-tender perennials, but while annuum varieties have a set growing season each year, chinense varieties set peppers year round. Also, chinense varieties tend to be smaller plants with rounder leaves and much hotter fruits.

Habaneros originated in the Amazon. An 8,500-year-old specimen of a domesticated habanero plant was found at an archaeological site in Peru, which means that people have been growing these peppers for a long time. Spanish colonists helped spread habaneros across the globe, to the point that 18th-century taxonomists mistook China for the habanero’s place of origin. Hence the species name, Capsicum chinense.

How Hot Is Hot?

Now let’s talk some chemistry.  Capsaicin is the chemical responsible for the heat, or pungency, of hot peppers. Hot peppers have a high concentration of capsaicin, mild peppers have a very low concentration of capsaicin. The exact pungency of a given pepper depends on species, variety, and growing conditions. Habanero plants that are watered every 7 days, for example, produce hotter peppers compared with plants that are watered on a regular daily schedule.

The Scoville Scale is like the heat index of the hot pepper world. It’s a measurement of the pungency of hot peppers. This scale rates the spicy heat in peppers based on the capsaicin concentration. The scale is named after its developer and has been around awhile, since 1912. It used to be based on taste tests (imagine being one of those testers!), but today capsaicin concentration is measured directly in labs using high-performance liquid chromatography (HPLC).

Capsaicin

Here are just a few Scoville ratings to give you an idea of the scale:

Pure capsaicin . . . . . . . . . . . . . . . . . . . . 16 million heat units

Standard US Grade pepper spray . . . . . 5.3 million heat units

Bhut Jolokia (Ghost) peppers . . . . . . . . .1 million heat units

Habanero peppers . . . . . . . . . . . . . . . . . 100,000 to 350,000 heat units

Jalapeno peppers . . . . . . . . . . . . . . . . . . . 2,500 to 8,000 heat units

Poblano peppers . . . . . . . . . . . . . . . . . . . . 1,000 to 1,500 heat units