A new world-record holder has entered the field of hot peppers: Pepper X. This proprietary pepper, bred by Ed Currie, was recognized in October 2023 by Guinness World Records as the hottest pepper ever independently tested. Currie is one of the few people to have tried Pepper X raw. By all reports, the taste test involves a burning sensation followed by several hours of intestinal cramping.
With a spiciness level of 2.693 million Scoville heat units (SHU) on average, Pepper X handily unseated the previous hottest pepper on Earth, the Carolina Reaper—also bred by Currie, who founded the PuckerButt Pepper Company, a hot pepper farm and pepper-product supplier in Fort Mill, S.C. (For comparison, jalapeños reach 2,000 to 8,000 SHU.) Scientific American caught up with Currie to talk about his heat-seeking trajectory and whether hot peppers can get even spicier.
An edited transcript of the interview follows.
What is it like in the world of hot pepper breeding? Is it a competitive field?
In the pepper-breeding world, there are really only a few of us who intentionally breed peppers. The rest of the people are growers, and they get what's called an odd phenotype and think they've got a new pepper. It's not that competitive. If it were, the Carolina Reaper wouldn't have held a record for 10 years. That's more just stuff on the Internet. Most of the people who actually breed peppers aren't on social media. We talk via the phone.
What does the day-to-day life of a pepper breeder look like?
Half the year we're processing peppers by drying them or turning them into pepper paste. The other half of the year we're breeding peppers. We cross-pollinate plants that have the attributes we want. If the resulting fruit has what we're looking for, we take the seeds out and plant them. If that comes out the same, that's the first generation. It takes anywhere between eight and 12 generations to stabilize a plant so you can start doing the testing.
At PuckerButt, we don't just breed peppers. We're one of the largest hot pepper farms in the U.S. We make hot sauce and pepper mash and dried pepper and pepper powder for all sorts of different manufacturers. Right now I'm making test batches of hot sauce, doing interviews and drying peppers at the same time.
When you're breeding peppers, what other attributes might you look for besides heat?
Ninety-nine percent of what we do is for flavor and looks. I like getting peppers to look really weird or breeding out different colors.
What's your favorite weird pepper that you've bred?
We have a particular variety of chocolate scotch bonnet that we call a UFO bonnet because it kind of looks like UFOs in pictures. It is a delicious pepper. It's not very high on the Scoville scale, but it is my absolute favorite pepper to eat. Don't get me wrong—I eat the superhot ones on a daily basis, but my favorites aren't superhot. They're in the midrange of the pepper world. [Editor's Note: The Scoville scale measures the number of times an extraction of a pepper's capsaicinoids needs to be diluted with a mix of sugar and water before a professional panel of tasters can no longer detect those hot compounds. In laboratory tests, a machine called a high-performance liquid chromatograph can quantify capsaicinoids and other compounds in dried samples of peppers.]
What makes Pepper X so hot?
The compound that makes peppers hot is called capsaicin. There are many different capsaicinoids, and these compounds react with a nerve receptor that only mammals have that sends a signal to our brain saying, “This is hot.” There are a lot of other compounds that can enhance the heat or tame the heat. You can increase the tannin levels in a pepper that is not so hot, such as a scotch bonnet, and it gives you the perception of more heat.
For Pepper X, I took a pepper that had a different set of capsaicinoids and bred it with the Reaper, and it turned out really hot. Nine out of 10 crossbreeds that we do go nowhere, and we have no expectation when we start. It's just playing around and having fun with science.
What is eating Pepper X like?
In hot sauce and in salsa and candy and things, it tastes delicious. But [when it is eaten] raw, the flavor lasts only for a millisecond, and then the heat is just taking off. And it's not a very pleasant experience. I wouldn't recommend eating it raw to anybody, and if somebody wants me to do it again, they're going to have to pay me a lot of money. A Reaper usually takes me about half an hour to recover from, including the cramps. Pepper X took me five to six hours. But I ate more peppers for dinner that night.
What's the advantage of having a superhot pepper?
The advantage of the superhot peppers is economy of scale. Say you're using cayenne to get a pepper sauce as hot as you want it. You might use two to three pounds of cayenne, whereas with Pepper X, to get the same heat, you would need maybe just an eighth of a gram of dried pepper.
I'll give you an example. There was a manufacturer who was using 11 55-gallon drums of a pepper in a recipe. I knew one of the executives there, and I said, “Just try it with one 15-gallon drum of Reaper.” They got the same heat and saved 80 percent of the money they were spending.
Do you think you can go hotter?
Oh, yeah, I know we can. We've tested a lot of peppers at a higher level, but we don't yet have a lot of years of averages. You show the average of the tests [when you're reporting the Scoville rating]; you don't show your single highest test. I think we can achieve a lot more, but there's really not much use for it—unless it tastes good.