There’s a fruit out there which causes excruciating pain upon contact, racing heartbeat, uncontrollable sweating and mucus, and ghastly intestinal distress. And, we eat it. Some of us with great joy. Of course, I’m talking about the chili pepper. It’s a polarizing ingredient, but without it, our food cultures wouldn’t be the same. 

The Tiny Fruit of Death

Chili peppers, including sweet bell peppers, belong to the genus Capsicum. These seed bearing fruits are native to the Americas and have been cultivated in places like Mexico, Bolivia, and Peru for thousands of years. They are one of the oldest domesticated crops on the planet. 

In markets all across the Americas, domesticated chili plants were traded and exported. The word chili comes from the Nahuatl language of Southern Mexico. Nahuatl was the language of the Aztecs who controlled trade in Mexico until the Spanish arrived. 

The Aztecs, Maya, and other Mesoamerican societies used chili peppers for not only food but as a medicine and bug repellant. The Nahuatl speaking Aztecs and earlier Mayan societies combined chili peppers and ground cocoa beans into a ritual drink called xocolatl. Even today, the fiery mixture of bitter chocolate and chili is one of the most adored combos in cuisine, most famously in the Mexican sauces known as mole. 

The Columbian Exchange

The Europeans originally thought the chili pepper was toxic. Around the time the first Europeans in the Americas were encountering the so-called ring of fire, black pepper was being traded in Europe and Asia. Black pepper, from the unrelated family Piperaceae, was big business. When the Ottoman Empire cut off trade to Europe, the Europeans sailed west to find new sources of riches. 

The Columbian Exchange began once ingredients, materials, and diseases started flowing between the continents, fueled by the colonizer’s exploitation of new resources. Once the chili pepper made it to Europe, it was brought on Portuguese ships as a tradable and possibly valuable good. Thus, the chili pepper made it to Asia and quickly spread around the globe, making it to Chili-crazed places like Thailand, India, and Sichuan province in China. 

The chili pepper has since wound up as a star ingredient in most cuisines around the world.  Household staples like hot sauces and tajin have become billion dollar enterprises and countries like China and Mexico have made agricultural empires out of the fruit. 

References to chilis permeate pop-culture too. Shows like Hot Ones put celebrities in the literal hot seat by feeding them chicken wings covered in various hot sauces ranging from the innocuous to the down-right evil. 

The Diverse World of Chilis

There are thousands of species of chilis, from wild Amazonian fruits to the common domesticated varieties we see in markets. Of these thousands of species, only five are widely domesticated. 

The most common are Capsicum annuum which includes the bell, jalapeño, and Asian varieties that evolved from the peppers carried on Portuguese ships. Habaneros, Carolina Reaper, and Scotch Bonnets belong to the Capsicum chinense species. In South America, the omnipresent aji peppers belong to Capsicum baccatum.

Capsicum plants produce the compound capsaicin, which mimics the pain receptors associated with heat or burning. Mammals are the only animal that can sense capsaicin. Most of the compound is located in the white fleshy part of the fruit closest to the stem. Removing this part of the chili will de-arm them, a technique that lets cooks infuse their food with the chili’s flavor without getting the full brunt of the heat. 

This burning sensation is measured in units called Scoville Heat Units, named after American pharmacist Wilbur Scoville in 1912. The higher the number, the greater the burn. Scoville came up with the numbers during his tests. He would serve his willing victims measurements of capsaicin infused alcohol. He would test the level of spice of various chilis by measuring the units of water he would have to add to the burning solution until his test subjects stopped feeling the sensation.

Scoville Heat Units, or SHUs, are perfect for gauging the power of your chili. A bell pepper comes at around 0. Jalapeños generally fall between 8-10,000. Going up on the scale you get to the heavy hitters. Habaneros and Scotch Bonnets usually lie around 350,000 SCUs while the Trinidad Scorpion and Carolina Reaper sit comfortably at over 2 million, the latter being the hottest. 

Why do we Eat Them?

Why do we eat chili peppers in the first place? For one, they contain vitamin C and numerous other nutrients. On top of that is the heat. This pain inducing feeling taps into our fight-or-flight response. We can’t die from eating chilis, but we may feel like it. Like bungee jumping or sky-diving, eating chilis could be that kind of flirtation with danger that many of us seek out. So, it looks like we enjoy eating spicy chilis simply for the thrill of it.