How to Lacto-Ferment Peppers

Why lacto-ferment peppers

Lacto-fermentation uses salt to hold back many spoilage organisms while salt-tolerant lactic acid bacteria (often Lactobacillus and related species) convert sugars into lactic acid. The result is a tangy, complex pepper that keeps in the refrigerator for months and works as a condiment, a topping, or the starting point for hot sauce.

It is different from vinegar pickling. A vinegar pickle gets its sourness from added acid, while a fermented pepper makes its own. If you want a shelf-stable, canned pepper, use a tested vinegar-based recipe from NCHFP instead (our banana pepper canning guide explains how that works), because a ferment is not a canning method.

Choosing peppers

Pick fresh, firm peppers. They should feel full and plump, not floppy or shriveled.
Avoid soft spots, mold, and dark pocks. Spoiled peppers do not ferment into good peppers.
Skip pre-washed, bagged produce if possible. Fermenters report that triple-washed produce may ferment poorly, since it may carry fewer natural microbes. Fresh farmers’ market or garden peppers are a good option.
Almost any kind works. Jalapeños, serranos, banana peppers, Anaheims, poblanos, shishitos, and sweet peppers are all commonly used. Very hot peppers such as habaneros work especially well for sauce.

Wear disposable gloves when cutting hot peppers, and do not touch your eyes.

Can you ferment peppers with just salt?

Yes. A basic pepper ferment needs only three things: peppers, salt, and water. Garlic, onion, herbs, and spices are optional flavor extras. A starter culture is not required, and many recipes rely on microbes already on the produce.

Equipment

A clean glass jar
A kitchen scale (strongly recommended for measuring salt)
A fermentation weight, or another way to keep the peppers under the brine
An airlock lid, or a regular lid that you open briefly each day
Non-iodized salt, such as pickling or kosher salt (iodine and anti-caking agents in some table salt can cloud the brine or interfere with fermentation)
Non-chlorinated water, such as filtered or spring water

Salt ratio

Published recipes for fermented peppers commonly use a brine of about 2 to 5 percent salt, calculated by weight. One experienced fermenter starts near 3.5 percent of the total weight of the vegetables and water, and prefers peppers between 3 and 6 percent total salt. A beginner-friendly middle ground is around 3 percent.

For a rough guide, 3 percent means 30 grams of salt per 1,000 grams of total water plus peppers. Measuring by weight is more reliable than tablespoons, since different salts have different densities. When in doubt, check an NCHFP or extension service recipe for the kind of vegetable you are using.

Step by step

Prep: Wash the peppers. Remove stems. You can leave small peppers whole (with a pierce or slit) or slice them into rings or halves. Add peeled garlic cloves if you wish.
Weigh: Put your empty jar on the scale, then add the peppers and aromatics to find the vegetable weight.
Make the brine: Dissolve your measured salt completely in non-chlorinated water. Make enough to cover.
Pack and cover: Pack the jar, leaving 1 to 2 inches of headspace, and pour in the brine.
Submerge: Weigh the peppers down so that none are above the surface.
Ferment: Cover with an airlock lid, or a loose lid. If you use a regular sealed lid, release the gas once a day. Keep the jar out of direct sunlight at a stable room temperature.
Taste: After a few days, taste a pepper. Move the jar to the refrigerator when it tastes right.

How long should peppers ferment?

There is no single answer. Many people ferment peppers for about 1 to 2 weeks for a bright, lightly tangy result. Others prefer a month or more, and one fermenter reports preferring about five weeks. Warmer rooms speed things up, and saltier brines slow them. Bubbling that slows or stops, a clearly sour aroma, and a pleasant tang are practical signs that you are in a good range.

Longer is not always better. Over time, peppers can soften and flavors can become muted, so if you are making a crisp pepper, refrigerate earlier.

Troubleshooting

A white, wrinkly film on top: Often kahm yeast. It is usually harmless to health, though it can affect flavor. Skim it off, make sure the peppers are still submerged, and consider using an airlock lid to limit air.
Fuzzy, raised, green, black, pink, or blue growth: This is mold. Discard the batch.
Cloudy brine: Normal.
Soft peppers: Too warm, too little salt, or fermented too long.
Peppers floating: Weigh them down more thoroughly.
No bubbles: Not always a problem, especially with a tight lid or cool room, but if there is no souring after a week or so and the brine does not smell tangy, restart.
Rotten or putrid smell: Throw it out.

Turning fermented peppers into hot sauce

Fermented peppers are a popular base for hot sauce. A common method is to ferment chopped peppers and aromatics in brine, then blend them with some of the brine, strain if desired, and bottle. The Homebrewers Association describes using a scale, gloves, a blender, and a sieve. If you want to store sauce for a long time or give it away, consider testing its pH with a pH meter or reliable test strips. A pH of 4.6 is the upper limit for safe storage of acid foods, not a goal, and most makers aim well below it. Check an extension service for current guidance. Keep homemade hot sauce refrigerated.

Storage

Move finished peppers to the refrigerator with their brine. Many sources suggest they keep for several months, though quality changes over time. Use a clean spoon to remove peppers, and discard if you see mold or notice off smells.

Best vegetables to lacto-ferment

Cabbage, carrots, cucumbers, cauliflower, green beans, radishes, and beets are all common choices, along with peppers. See how long to ferment cauliflower for another beginner-friendly example. Which vegetables to avoid depends on the vegetable and how fresh it is. Do not ferment spoiled or moldy produce, and look for tested guidance if you want to ferment something unusual.

How to use fermented peppers

Chop into tacos, eggs, or grain bowls.
Blend into hot sauce.
Add to sandwiches and burgers.
Stir a spoonful of the pepper brine into soups or dressings.

For ideas on using fermented ingredients in everyday dishes, see our guide to fermented foods that taste good.