Chile peppers have been on the menu since at least 6,000 years ago, when people living in current-day Mexico cultivated them for their heat and flavor. The world-spanning Portuguese Empire helped spread them to nearly every corner of the planet in the 16th and 17th centuries, and now they’re a cornerstone of dozens of cuisines on multiple continents. These fiery fruits are powered by capsaicin, a pungent chemical repellant designed to drive off mammals while allowing birds (who are immune to its effects) to eat the plant and disperse its seeds widely.
Charts of chiles’ Scoville Heat Units (intensity of pungent heat) are widely available and are a rough gauge for what you’re getting into when you bite into that Carolina Reaper like a strawberry. But keep in mind that peppers vary wildly depending on growing conditions—a jalapeño can be anywhere from 2,500–10,000 Scoville units and a serrano can drift between 10,000–20,000. Your best bet is to try a tiny piece before cooking and proceed accordingly. (The Carolina Reaper is north of 1,000,000 units, by the way, so tread lightly.)
In “On Food and Cooking,” author Harold McGee explores the paradox of spicy food in a section called “Why Pain Can Be Pleasurable.” He notes that beyond being the thrilling “edible equivalent of riding a rollercoaster,” the pungent compounds in hot foods “…induce a temporary inflammation in the mouth, transforming it into an organ that is more ‘tender,’ more sensitive to other sensations. Those heightened sensations include touch, temperature, and the irritating aspects of various other ingredients including salt, acids, carbonation (which becomes carbonic acid), and alcohol.”
Chili vs. Chile vs. Chilli: What’s in a Name?
Few things are as challenging about chile peppers as their name. Dictionaries recognize three variants, so pick your poison:
Chili is the standard in historically English-speaking parts of the United States and Canada. This is a confusing choice as the word also describes the stew chili con carne (which literally means “chili [powder] with meat”).
The most common Spanish spelling is chile, and the word can refer to both the plant and the fruit. The plural is chile or chiles.
And chilli was, as per Wikipedia, the “original Romanization of the Náhuatl language word for the fruit,” and the preferred British spelling in the Oxford English Dictionary. You can encounter chillies throughout the former British empire.
Note that none of these words appear to have anything to do with the name of the country, Chile.