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Brine Fermented Peppers in a Ball Jar

Making fermented hot sauce is a unique method for preserving fresh peppers and other produce. Fermenting peppers is also a method for creating a hot sauce without vinegar.

With a proper pH, the sauces can keep in the refrigerator for many months, and we believe the sauces improve in flavor over time.

In This Article

What is Fermentation (Lactofermentation)?

Like it or not, bacteria are everywhere. For the folks who don’t like the sound of that, many bacteria are beneficial to our overall health. If you’ve eaten yogurt, you have likely heard of the benefits of “live active cultures.” This benefit is also present in any fermented food, including hot sauce!

Fermentation is a natural microbial process that occurs when organic materials are broken down into simpler molecules by bacteria. Lactofermentation is the process that occurs in most food fermentation, and is perpetuated by the lactobacillus bacteria, which is contained on most plants, vegetables and within the human body.

“Lactobacillus exhibits a mutualistic relationship with the human body, as it protects the host against potential invasions by pathogens.”


Fermentation is used to produce wine, beer, liquors and many other common foods like sauerkraut and kimchi. Fresh produce is submerged in a salty brine and deprived of oxygen. This environment is unlivable for most other forms of bacteria, but is perfect for lactobacillus.

The lactobacillus is then free to extract energy from carbohydrates like sugars by good bacteria, producing lactic acid and CO2. This lowers the pH of the product, thereby preserving it safely.

Lacto Fermentation Dangers

One of the common questions regarding lacto-fermentation is, “is it dangerous?” Put simply, lactofermentation is not dangerous when set up and monitored properly. However, precautions should be taken to avoid common issues with fermentation, including mold growth and spoiling.

Here are the common signs that lactofermentation has gone wrong:

  • Rotten smell
  • Fuzzy mold growth on surface
  • Overly slimy vegetables
  • Rancid flavor (spit it out!)

Avoiding these negative outcomes is easy if you follow our steps to producing a healthy ferment from the start.

Making Brine Fermented Hot Sauce

There are two basic methods of fermenting peppers for hot sauce. The first is by making a simple pepper mash. This involves finely chopping or food processing the peppers, adding 2-8% salt by weight, and compressing the mixture into a fermentation vessel to remove all air pockets.

Mashes are great to use as a base for hot sauce, but usually require the addition of more ingredients after fermentation. They also take up less space, as the produce is chopped before fermenting.

The other method is to create a salt brine and submerge whole or sliced produce in the liquid. This is the method we will share today, as it is an all-in-one method to produce a hot sauce.

The process of fermenting hot peppers is very simple. However, it is not a set-it-and-forget-it method of preservation. You will have to monitor your ferment on a once-daily basis to avoid any potential issues along the way.

Materials & Ingredients

  • Glass jars
  • Air lock lids (Get on Amazon)
  • Fermentation weights (Optional, get on Amazon)
  • Kosher or sea salt (without iodine or anti-caking agents)
  • Filtered water (chlorine-free)
  • Hot peppers
  • Fresh garlic (optional, but recommended)
  • Other produce (optional, such as carrots, onions, cauliflower, etc.)

How To Make Brine Fermented Hot Sauce

This fermented hot sauce will use 4 basic ingredients: Peppers (jalapeno, ancho, and habanero), garlic, kosher salt, and water. You may add sugar or other flavorings to your liking.

  1. Prepare peppers.

    Wash and dry your hot peppers. Cut off the tops and slice the peppers lengthwise. Remove seeds (optional). You can also slice the peppers into smaller pieces, but it is not necessary. Always wear gloves when handling spicy peppers!Sliced peppers and garlic

  2. Sterilize jars.

    If you are using a brand new jar, it should be pre-sterilized. However, if you are using an older jar you should boil the jars in a large pot for 10 minutes to ensure the jars are clean. Remove jars from boiling water and allow to full dry on a drying rack.Pepper Jar drying on rack with washed peppers on cutting board

  3. Fill jars and weigh ferment.

    Place the empty jar on a kitchen scale and zero the scale. Then, add the peppers and cover with filtered (unchlorinated) water. Take not of the weight in grams. Tip: Always put the smaller items first, as they have a tendency to float.

  4. Add 2-4% salt.

    Based on the weight of your ferment and water, add at least 2% salt to the water. This is a very important safety measure to make sure other pathogens can’t take hold in your ferment. Mix thoroughly to ensure the salt dissolves.

  5. Keep produce submerged.

    There are many creative ways to keep the peppers submerged in the brine. You can use a long pepper and wedge it below the lip of the jar. Or, ideally, use fermentation weights (see on Amazon).

  6. Cover jars.

    During fermentation, carbon dioxide will be produced and will cause pressure if the jars are tightly closed. We like to use specifically designed airlock lids from Amazon. These allow gas to escape, but not to reenter the jar. If you do not use an airlock, you will have to allow CO2 to escape on a daily basis by burping the jars to prevent cracking.

  7. Ferment for 2-3 weeks or longer.

    How long fermentation takes is always different, with the biggest factor being temperature. If you keep the jars in a warm place, the process can happen quickly. Check on your ferment daily to burp the jars, check for yeast or mold, and to eventually taste test for readiness. The level of fermentation will give distinctly different flavoring, so deciding when to refrigerate is up to your preference!
    Important! Measure for pH with a good pH meter to ensure the brine is below 4.6. This is the pH at which botulinum toxin can no longer form and is a good minimum acidity to target. Fermentation Cloudy Liquid in jar

  8. Strain peppers from brine.

    Pour your fermented peppers through a strainer, and be sure to keep the liquid. This will be used to thin out your hot sauce to the desired consistency.

  9. Blend peppers.

    Add the peppers and garlic to a blender, and add a small amount of the brine to start. Don’t add too much, as this can cause an overly thin sauce. After blending, add slightly more brine until the sauce is just thin enough.
    Optional: Add your choice of vinegar in addition to the brine to have a more acidic flavor, and to keep the hot sauce for longer.

  10. Bottle and refrigerate.

    Unless your ferment is below pH 3.3, or you are planning to cook your sauce, it should be stored in the refrigerator. Refrigeration nearly halts the process of fermentation, preserving the desired flavor and preventing CO2 buildup. Use the original mason jar, or use a small funnel to fill hot sauce bottles.

Fermentation Brine (How To Get It Right)

Getting the proportions of salt-to-water correct is important. The goal is to have a 2-3% concentration of salt in the water by weight. Using grams, weigh both the water and the peppers/produce and multiply it by 0.025. Add at least that amount of salt to the mixture.

Tip: Be sure to factor in the amount of space your peppers will take up in the jars. Too much salt will result in an overly salty sauce.

What pH Should My Fermented Hot Sauce Be?

We always test the pH of our fermented hot sauce to ensure it is adequately acidic. As fermentation takes place, the pH will drop lower and lower, becoming more and more acidic.

To put it simply, aim for a pH of 3.7 or lower when making fermented hot sauce. This ensures that your sauce will have a safe and long shelf life in the refrigerator. Some people target a pH of 3.5 for fermented hot sauce.

Technically, any pH below 4.6 will be stable, but we like to be cautious and allow our ferments to become very acidic before processing further.

How To Lower pH of Hot Sauce

If your sauce is tasty, but the pH is too high, you can add vinegar to bring the pH lower. Add a few tablespoons of vinegar (white, white wine, apple cider, etc.), blend, and test the pH again. Once it is at or below 3.7, you can store it in the refrigerator.

How To Tell When Fermented Peppers Are Done

Fermentation will continue until you force it to slow by refrigerating. Foods fermented for longer tend to have a less sweet, more sour flavor. Each person will prefer a different level of fermentation.

In short, fermented peppers are done when they have a more sour, pungent aroma and flavor. After the first 2 weeks, test your ferment regularly until it has reached the desired flavor.

Some people prefer a longer ferment for a more *funky* flavor, while others like a milder ferment. You can ferment your sauce as long as you like, so long as it doesn’t grow mold or spoil.

What Does Fermented Hot Sauce Taste Like?

You may not know it, but many of the most common table hot sauces are fermented. Ever heard of Tabasco? What about Frank’s RedHot? Yep, both use fermented pepper mash as a primary ingredient.

Fermented hot sauces have a slightly sour taste that is typical of many fermented foods. During fermentation, bacteria consumes sugars and other carbohydrates, reducing sweetness and developing a more acidic, sour flavor.

The reason for the slightly sour flavor is the production of lactic acid during the fermentation process. These acids replace sugars, and lead to a very distinctive flavor profile. The flavor of fermented hot sauce is difficult to describe in full, but it can be loosely described as slightly sour with an overall tangy character.

To really know how fermented hot sauce tastes, try making some yourself with our guide above!

How Long Will Fermented Hot Sauce Last?

Most fermented foods will last for months or even years when refrigerated. Over time, the flavor of your fermented hot sauce will continue to develop, often becoming more and more delicious. However, some people think that over-fermented foods can be a bit too pungent. Others love it (like me).

As a rule of thumb, homemade fermented hot sauce will last 2-3 months in the refrigerator. We are confident that they can last much longer, but it is always wise to be on the safe side.

Always be sure to inspect your fermented sauce for mold growth or odd smells. If you are uncertain whether anything has gone wrong, you’re probably better off discarding.

What Is The White Stuff On My Fermentation?

There are a few things that a white substance on your ferment could be. The more common is harmless yeast that can simply be removed. The other might mean you need to discard your fermentation.

Kahm Yeast

This is very common and is harmless to your food. You can safely consume the yeast, but most choose to remove as much as they can with a clean spoon before storing the ferment in the refrigerator.

What Causes Kahm Yeast?

There are a number of factors that can cause Kahm yeast to form on your ferment, but the most common are:

  • Higher temperature
  • Open-air fermentation (no closed lid)
  • Fermenting sweeter vegetables, like peppers or carrots

This yeast is a live fungus that is common in the atmosphere and tends to thrive in a fermentation environment.

What Does Kamh Yeast Look Like?

Kahm yeast can often be mistaken for mold, but if you use these simple identifiers, you will know when your ferment is still safe:

  • Stringy, wrinkled, film-like look
  • White to off-white color
  • Not fuzzy, but more flat
  • Bubbles of carbon dioxide often get trapped in Kahm yeast

Here is a picture of Kahm yeast.


Mold is usually a reason to discard your ferment. There are ways to salvage a moldy ferment, but I prefer to simply call it a loss and start over.

What does mold look like on a ferment?

There are many types of mold, but most exhibit these similarities:

  • Fuzzy appearance rather than smooth
  • Raised from the surface
  • Spotty at the beginning, eventually coming together to form a layer

There are some harmless molds, but it is hard to be sure without doing your own research. If you suspect you have mold, we recommend that you get rid of the ferment.

Alternatively, you can simply skim away the top layer, careful to remove any and all visible mold. The remaining ferment should still be safe to eat.

Here is a picture of mold on a ferment.

Other Methods Of Preserving Hot Peppers

Want another option for preserving your hot peppers? There are tons! Check out our article on the many methods of preserving peppers here. You’ll learn how to pickle peppers, freeze them and lots of other cool tricks. Never let your peppers go to waste!

We hope you enjoyed this guide to making fermented hot sauce at home. Let us know how your sauce turned out, and if you recommend any other tasty ingredients to spice things up.

Calvin Thumbnail


One of the original Pepper Geeks! When Calvin isn’t gardening or learning more about peppers and botany, he might be traveling new places or playing some music.


Tuesday 10th of October 2023

Do I need the amount of brine in the picture above my peppers? Also, if you wanted to add fruit to the sauce, such as apple or cranberry would that have to be fermented with the peppers?


Sunday 1st of October 2023

Everyone I know who makes hot sauce uses the fermentation method, and after reading this it's still a mystery to me why anyone goes through all of this. I don't use salt for anything, I get enough without trying. "Brine?" No thanks. And after all of this it has to be refrigerated, and I don't find the finished product to compare favorably to mine. I make hot sauces with vinegar and peppers and no other ingredients and use the stove top method. The many who have tried it love it, it has great flavor and as much heat as anyone can stand for my hottest sauces. Right now I'm working on a bottle I made two years ago that's been in my cabinet unrefrigerated until I cracked into it. I've used older stuff than that and no one can tell the difference between 3 years old and 3 days old. PH level is slightly above or below 4. Takes me about a half an hour to make a batch. I usually age it for a minimum of 3 days under refrigeration, but I'm not sure that's necessary.

Muncy Coogins

Thursday 19th of October 2023

@Daren, cool. You're probably hanging around the wrong page then...

Vaudo Aridas, Rosemarie

Monday 11th of September 2023

How can commercial hot sauces be stored on shelves? Is there another process they employ?


Tuesday 12th of September 2023

Yes, a combination of heating to a high temperature and low pH


Sunday 23rd of July 2023

Hi! I think the kit I bought of amazon doesn't fully fit on the jars I have. Should I be able to smell the ferment if I get close to the seal of the jar? I'm worried air is getting in.


Monday 24th of July 2023

If air is allowed in, there's a pretty good chance of developing mold in the air space.

Doc White

Tuesday 18th of July 2023

Can I can, water bath this recipe?