# What Is Kimchi? A Beginner's Guide to Korea's Fermented Staple

Source: https://fermentnest.com/blog/what-is-kimchi-and-how-is-it-made
Published: 2026-11-02
Publisher: Ferment Nest

Kimchi is a Korean fermented vegetable dish, most often made from salted napa cabbage coated in a paste of chili flakes, garlic, ginger, scallions and a salty seasoning such as fish sauce or salted shrimp. After a few days at room temperature and then time in the refrigerator, it becomes tangy, spicy and savory, with a slight fizz. There are hundreds of regional and seasonal variations, including radish, cucumber and white versions with no chili at all. This guide explains what kimchi is, how it is made, how it tastes at different ages, and how to enjoy it.

## What kimchi is made of

The classic version, often called baechu kimchi, starts with napa cabbage that is salted to draw out water and soften the leaves. The cabbage is then rinsed and coated with a seasoning paste. Common components include Korean chili flakes called gochugaru, garlic, fresh ginger, scallions, sliced radish or carrot, and a savory element such as fish sauce, salted fermented shrimp or a plant-based alternative.

Many recipes also add a thin porridge made from glutinous rice flour or plain rice flour and water, which helps the paste cling to the leaves and gives the microbes a little extra food. The chili flakes matter for both flavor and color, and our guide to gochugaru flakes explains the differences between coarse, fine and sun-dried types.

[Compare gochugaru flakes](https://fermentnest.com/best/best-gochugaru-flakes)

## How kimchi ferments

Kimchi is a lacto-fermented food. Salt creates an environment where salt-tolerant lactic acid bacteria, already present on the vegetables, can grow while many unwanted microbes cannot. The bacteria turn natural sugars in the vegetables into lactic acid, which lowers the pH, preserves the food and produces the tangy flavor. Carbon dioxide forms as a by-product, so a jar of fermenting kimchi often bubbles and can push liquid up.

At room temperature the process becomes noticeable within a day or two, and many people move the jar to the refrigerator once it tastes pleasantly sour. In the cold, fermentation continues much more slowly, so the flavor keeps developing over weeks. The exact timing depends on temperature, salt level and the vegetables used, so tasting regularly is more reliable than following a fixed schedule.

## What kimchi tastes like

Fresh kimchi, eaten within a day or two of mixing, is crunchy, salty and spicy with a bright, raw garlic edge. As it ferments, the flavor becomes more sour and complex, with deeper savory notes. Well-aged kimchi is quite sour and softer in texture, and in Korea it is often preferred for cooking rather than eating raw.

Heat level varies with the chili flakes and the amount used. Milder styles use less chili or none at all, such as white kimchi, which is a gentler, brothy version. If you are new to kimchi, buying a small jar from a Korean grocery or ordering one at a restaurant is a good way to learn what level of sourness and spice you like before making your own.

## Common types of kimchi

Baechu kimchi, made with whole or cut napa cabbage, is the type most people picture. Kkakdugi uses cubed radish and has a firm, juicy bite. Oi sobagi is a cucumber version stuffed with seasoning and usually eaten fairly fresh. Nabak kimchi is a lighter water-based style with a thin, refreshing brine.

There are also seasonal and regional variations using scallions, mustard greens, perilla leaves and other vegetables. Because kimchi is a technique more than a single recipe, you can adapt the ratios and vegetables to what you have, as long as you keep the salt level suitable and the vegetables submerged under their brine. Our article on making kimchi at home covers a simple method without special equipment.

## How to store and serve kimchi

Kimchi is usually kept in the refrigerator in an airtight container once it reaches the flavor you want. Because it keeps producing gas, it is wise to leave some headspace in the container and open it carefully, since contents can spurt. Containers designed for kimchi have lids or valves that help with gas and smell, and our kimchi container guide compares options.

To serve it, most people eat it as a side dish with rice and other meals. Older, more sour kimchi works well in stews, fried rice, pancakes and grilled cheese sandwiches. Use a clean utensil each time rather than your fingers or a used fork, and press the kimchi down under its liquid after each serving, because exposed pieces are the ones most likely to spoil.

[Browse kimchi containers](https://fermentnest.com/best/best-kimchi-containers)

## Dietary notes and safety

Traditional kimchi often contains fish sauce, shrimp or other seafood, so it is not vegetarian or vegan unless made with a plant-based substitute. Anyone with a shellfish or fish allergy should check labels carefully. Kimchi is also fairly high in sodium, which matters for people who watch their salt intake, so portions are worth considering.

Kimchi is often described as a probiotic food, but the live microbes vary between batches, and pasteurized or cooked products will not contain them. It is best thought of as a flavorful part of a varied diet rather than a health remedy. As with any ferment, discard it if you see fuzzy mold on the surface or smell something truly rotten rather than sour. White film on the surface can be harmless yeast, but when in doubt, throw it out.

## Where to start

If you want to try making kimchi, begin with a small batch of napa cabbage and a simple paste, and keep notes on salt and fermentation time. A clean jar, a weight to hold the vegetables under the brine and a cool spot for the first day or two are the main requirements.

If you plan to make it regularly, a crock or onggi can give you a steady environment, and our guide to onggi crocks explains how these traditional vessels work. Whichever route you choose, remember that the first batch is practice. Taste it at different ages to find your preferred point, and adjust the salt, spice and time on the next round.

## Related buying guides

- https://fermentnest.com/best/best-kimchi-containers
- https://fermentnest.com/best/best-gochugaru-flakes
- https://fermentnest.com/best/best-onggi-crocks