Does Fermentation Make Peppers Hotter?

Have you ever tried fermenting your own peppers at home or making your own fermented hot sauce? If so, you know how fermentation changes so many things about the taste of the peppers.

You get somewhat more of an umami flavor that tastes more subtle in comparison to regular hot peppers or hot sauce, which can really hit you in the face with heat.

So does fermentation make peppers hotter? The answer is not. It actually causes your peppers or hot sauce to lose some of its heat. Keep reading to learn more.

person holding red chili pepper in their mouth

What Makes Peppers Hot?

What brings the heat in peppers and makes them spicy is capsaicin. Capsaicin is a chemical compound first discovered after being isolated from chili peppers.

Capsaicin is mostly found in the fruit of the pepper (so the pepper itself) but capsaicin compounds can also be found in the stem and leaves of the pepper plant.

The more capsaicin a pepper has, the spicier it is. You might have seen hot peppers or hot sauces ranked on a scale called the Scoville Scale. The Scoville Scale correlates with the concentration of capsaicin in the pepper or hot sauce. The higher up on the Scoville Scale a pepper is, the hotter it is.

Coming into contact with capsaicin causes significant irritation and burning. You might have experienced this when dicing peppers at home while cooking. Maybe your fingers started to burn a bit, and if you happened to touch your face or eyes, you could really feel the burn.

Did you know that capsaicin is also used to treat pain? Capsaicin cream is very commonly used to treat minor aches and joint pain in arthritis.

The longer peppers stay on the vine, the hotter they get. This is because as peppers age on the vine, they produce more capsaicin. 

As capsaicin increases, not only will the spice level change, but the color will change too. Hot peppers are green at first, then will turn yellow, orange, or red as they mature. This is when they’re usually picked from the vine.

chili plant with red and green peppers

Jalapeños are an exception. They’re usually green when you buy them in the store, but if you let them grow on the vine, they turn red. That’s when you know they’re extra spicy.

What Does Fermentation Do to Peppers?

Fermentation is a chemical process that’s conducted by microorganisms, like bacteria and yeast. For fermentation to work and produce a safely edible product, you want to keep the bad bacteria that will make you sick and cause spoiling out and keep the good bacteria that will conduct fermentation in.

To do this, you can keep the bad bacteria out by creating an anaerobic environment (or an environment without any oxygen). How do you create an anaerobic environment? You need some sort of airtight container (like a jar) and a medium like salt brine solution (people also ferment in other mediums like honey).

Good bacteria like lactobacillus, can thrive in an anaerobic environment. When peppers are placed in an airtight container with a salt plus water solution, these and other similar bacteria and yeast consume the carbohydrates (or sugars) in the peppers and convert them to acid.

This is how peppers are fermented. But does fermentation affect how hot peppers can get?

Does Fermentation Make Peppers Hotter Over Time?

Fermentation actually makes peppers less hot. You’ll find that fermented hot sauce is milder than regular hot sauce, but has much more layered and complex flavors (especially if you’re fermenting it in oak barrels).

The loss of heat due to fermentation probably happens because the bacteria and yeast are digesting the peppers and breaking them down.

Many fermenters who want to keep things hot and spicy will use hotter peppers or will use more mature peppers that have more capsaicin in them when making fermented peppers or fermented hot sauce at home. 

Fermenters will also make sure to keep the inner white membrane that holds the seeds in peppers, as this is where all of the capsaicin can be found.

red chili sliced showing inner membrane and seeds

For those of you trying to reduce the heat, removing this inner part of the pepper will help a lot. Other tricks include smoking the peppers before fermenting them and adding sugar. You can also try fermenting your peppers in honey!

In Summary

Capsaicin is the culprit that makes peppers pack their punch and bring the heat.

When comparing regular peppers and hot sauce to fermented peppers and hot sauce, the level of heat mellows out with the process of fermentation.

That being said, don’t let that fool you because you can still make some pretty spicy fermented peppers or fermented hot sauce. Depending on if you want something more spicy or less spicy, just follow my tips in this article when making these yourself at home!