Hot! Capsaicin, Chili Peppers, and Jalapeño Jelly

Cayenne. Photo by Amy Davis Roth

This post was inspired by a recent series of photos taken by Surly Amy of peppers she is growing at her home.

The heat in peppers is an evolved mechanism that discourages mammals and other animals from eating the pepper and thus destroying the seeds. When we eat chili peppers, a compound called capsaicin triggers the receptors in our pain neurons. As Barb Stuckey writes in Taste What You’re Missing: The Passionate Eater’s Guide to Why Good Food Tastes Good, humans seem to be the only species on Earth that actually enjoys the pain caused by tasting capsaicin. In an experiment by Paul Rozin, rats who were fed a diet of spicy food eventually became used to it, but later they never chose it over their regular food.





Poblano on the plant. Photo by Amy David Roth
Poblano on the plant. Photo by Amy David Roth

Why do some people have a higher tolerance for spicy food than others? No thorough research exists currently on whether some people with pain receptors that are less sensitive to capsaicin, but studies do show that you can desensitive these nerve endings over time, thus building up a tolerance, and that people who can be generally categorized as “sensation seekers” and enjoy the thrill of things like roller coasters and gambling also expressed more enthusiasm for spicy food.

The Scoville Scale is used to rank peppers by how hot they are. The number of Scoville Heat Units (SHU) indicates the amount of capsaicin present per unit of dried mass. The original test, developed in 1912, involves a panel of tasters sampling alcohol extracts of capsaicin oil from a specific pepper which has been diluted with sugar and water to different degrees until it is no longer detectable–the point at which the measurement is made. Because these results are fairly subjective, they vary widely and thus the technique is flawed. Today, spice heat is measured using high performance liquid chromatography and the resulting can be divided by 15 and reported as Scoville units.


Ghost chili!
Ghost chili! Actually, these are padron peppers. Most are mild, but about 1 in 5 is mouth-searingly hot. Photo by Amy Davis Roth

Here are the Scoville rankings of some familiar–and some extreme–chili peppers:

Bell peppers – 0 SHU
Poblano – 1000-2500 SHU
Jalapeño – 3000-8000 SHU
Cayenne – 30,000 – 50,000 SHU
Bhut Jolokia (Ghost chili) – 1,000,000 SHU
Trinidad Moruga Scorpion Pepper – 2,000,000 SHU (the equivalent of law enforcement-grade pepper spray)







If you have a taste for Schadenfreude, you might enjoy this video about the Moruga Scorpion, including taste tests. NSFW if your work minds bleeped f-bombs.


Jalapeños. Photo by Amy Davis Roth
Jalapeños. Photo by Amy Davis Roth

Below is a recipe for jalapeño jelly which is a fun way to highlight the flavor of the chili pepper. Be careful handling these peppers in your kitchen, and follow…

…Surly Amy’s tips for not burning the S@#% out of you hands
1. Wear gloves when working with hot fresh peppers.
2. Seriously, wear gloves.
3. If you don’t wear gloves and feel a tingling sensation begin IMMEDIATELY wash hands with soap and water. To control the capsaicin burning after it has set in, soak hands in whole milk or a product with milk such as yogurt, though cold whole milk seems to work best. There’s a protein found in milk called casein that bonds to the pain receptors and blocks or pulls away (I’m not a chemist) the capsaicin found in peppers. Replace the milk with fresh when the pain returns. When the pain becomes manageable, holding an ice pack seems to help.
4. Next time wear gloves.



image_8Jalapeño Jelly (based on this recipe from Serious Eats)

1/2 cup chopped jalapeño peppers (I used two large chilies), seed and veins removes, or leave some in for a spicier jelly
1/2 cup chopped green bell pepper (I used half of a large one)
3 cups sugar
1/2 cup apple cider vinegar
2 tablespoons fresh lime juice
1 (3-ounce) package liquid pectin (I mixed 1 box of Sure-Jell powdered pectin mixed with 1/2 cup of boiling water and then used 3 ounces of that–next time I would mix in 3/4 cup of water, as this was pretty thick)
Pinky nail-sized smidge of butter (optional)




Blend the peppers in a food processors until they are almost smooth:

peppers pepper puree

Add the puree to a large heavy pan along with the sugar and vinegar and bring to a rolling boil, stirring constantly. Boil for 3 minutes, stirring occasionally.

jelly1 jelly2

Stir in pectin and lime juice and return to a boil for one minute. Remove from heat and let foam settle, or add the butter if using, which will help dissipate the foam. Otherwise, skim off and discard any foam.


Spoon into jars or other heatproof, non-reactive containers with lids. Allow to cool for 1 hour before closing the lids and putting the jars in the fridge to cool. will keep in the refrigerator for up to 3 weeks.


The traditional Southern way to serve jalapeño jelly is with cream cheese and crackers. Enjoy!


Photos by Anne Sauer unless otherwise specified

Anne S

Anne Sauer is an atheist with an appetite for science, good food, and making connections between the two. She is currently pursuing her MBA in Sustainable Management at Presidio Graduate School in San Francisco. Her favorite foods are salted caramel ice cream and chicken tikka masala. You can find her on twitter @aynsavoy.

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  1. Just a quick addendum to the evolution of capsaicin production: It was not evolved in relationship solely to mammals, it also deters some insects and many fungal pathogens.

    But anyway…. Mmmm peppers I like a hot thai chili paired with milk chocolate myself. Easy recipe too: get a thai chili pepper and sit it on a bar of Hershey’s. Eat

  2. Thanks, Chris–updated!

    I’ve had spicy hot cocoa, but I don’t think I’ve ever tried candy bars and chilies. Fun!

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