What is kimchi, and is it healthy?

Kimchi is a traditional Korean side dish of salted, fermented vegetables. It’s been around for hundreds of years. Kimchi has gained popularity in the West more recently, partly for its flavor and versatility and partly because of its reputation for being healthy.

Kimchi can be made from a variety of vegetables, and even fruits, but the most recognized version — baechu kimchi — is made with cabbage. Alongside cabbage, it often contains radishes, scallions, carrots, garlic, ginger, chili flakes, and other flavorings.

Kimchi has a sour, salty, savory, and often fiery taste. It can also feel slightly fizzy on your tongue due to fermentation by live probiotic bacteria.

Consuming probiotic foods like kimchi might help to improve the diversity of the good bugs in your gut microbiome — the trillions of bacteria that live in your gut — which is essential for good health. 

Using ZOE’s at-home test, you can discover which types of bacteria live in your gut. From this information, we can give you personalized advice for boosting your “good” bacteria. 

You can learn more by taking our free quiz.

Read on to learn how kimchi is made, how to eat it, and whether it really is healthy.

How is kimchi made?

There are countless recipes for kimchi, and in Korea, families often have their favorite ingredients and particular ways of doing things. However, there are similarities between most recipes.

The main ingredient in kimchi is most often cabbage. Traditional Korean kimchi uses baechu, which is also known as napa cabbage.

The cabbage is cut into quarters lengthwise, then salted or brined. This draws out the excess water, which helps to preserve the cabbage.

Kimchi doesn’t have to be spicy, but most traditional recipes use Korean chili flakes called gochugaru, or sometimes a chili paste called gochujang. 

The chili is blended into a paste with garlic, ginger, and often a small amount of rice flour mixed with water. Often, people add fish sauce or salted preserved shrimp, which bring a savory “umami” flavor and may help with the fermentation process.

If you want to make vegan kimchi, you can leave these out or substitute them for miso. 

Thinly sliced vegetables, such as scallions, radishes, and carrots, are added to the paste and left to infuse for a short time. This mixture is then rubbed onto the drained cabbage leaves.

Finally, the coated cabbage is packed tightly into a jar or other air-tight container, sometimes with a small amount of the leftover cabbage juices to cover it. It’s important to leave some space in the container for the carbon dioxide produced by the fermentation process. 

Fermentation

Fermentation is when bacteria break down food into other compounds. These change the flavor of the food and can also be good for your body.

Kimchi usually takes 1–2 days to ferment at room temperature or several days in the refrigerator. However, just like the ingredients, the length of fermentation can vary. 

Some recipes advise tasting the kimchi each day to see how the flavor is progressing.

In kimchi, fermentation usually happens thanks to “wild cultures” — the microbes that are naturally present on the vegetables. Most of the fermentation in kimchi is due to bugs called lactic acid bacteria. 

To prevent harmful microbes from spoiling the fermentation, it’s important to make sure the equipment and surfaces you use are clean throughout the process and that you wash your hands before each step.

Buying and storing kimchi

While making your own kimchi can be fun, it’s quite easy to find kimchi at grocery stores, health food stores, and Asian markets.

If you want to get the full probiotic benefits of kimchi, check the label to make sure it contains live bacteria. Although most kinds do, some may be made with vinegar or pasteurized, which kills the beneficial bacteria.

When you open a jar of live kimchi, you might see it bubble. This is nothing to worry about and is actually a good sign, showing that the probiotic bacteria are alive and fermenting the kimchi.

Once open, you should store kimchi in the refrigerator. As the kimchi ages, the vegetables will become less crisp, and the flavor may get more sour as fermentation continues. 

For safety, it’s best to eat it within 1 week, although it can last up to a year. If you see mold on the surface of the kimchi, it’s definitely time to throw it away.

Is kimchi healthy?

Kimchi has a growing reputation as a health food because it contains probiotic bacteria.

Probiotics are “good” bacteria like those in your gut, which some research suggests may have a range of health benefits, including regulating immune function and influencing your mental health. You can also find probiotics in other fermented foods like live yogurt, kefir, sauerkraut, miso, and some aged cheeses. 

As well as probiotics, kimchi contains a range of vitamins, including vitamins A, B, C, and K, and minerals like calcium, iron, phosphorus, and selenium. 

However, if you need to watch your sodium levels for health reasons, you should consider limiting the amount of kimchi you eat due to its high salt content. 

The vegetables in kimchi mean it’s also high in fiber. Fiber provides food for your gut bacteria, so it can help the probiotics in kimchi thrive in your gut. 

When you join ZOE, you take an at-home gut health test so we can analyze your gut microbiome. We also test your blood sugar and blood fat responses to food. 

With the ZOE program, you get a breakdown of the bugs you’re hosting and personalized nutrition advice to help you find the foods that are best for your unique body and your long-term health goals. Take our free quiz to learn more.

Studies involving kimchi

There are some studies investigating the health benefits of kimchi, specifically. However, most of this research has been carried out in small numbers of people over a short amount of time.

For instance, some limited research suggests that eating kimchi may help with certain digestive issues. 

In one study, 20 people with a history of digestive problems ate around half a cup, or 75 grams, of kimchi twice each day for 14 days. They reported significantly reduced symptoms, including less abdominal pain, heartburn, acid reflux, bloating, belching, and passing gas. 

Other scientists have looked at whether eating kimchi might help tackle a type of “bad” gut bacteria called Helicobacter pylori. This bug can cause long-term inflammation of the stomach lining, leading to stomach ulcers. It is also linked to gastric cancer. 

One study involved 32 people with the H. pylori bug. After eating 100 g of fermented kimchi every day for 10 weeks, participants’ gut microbiomes had changed significantly. Health markers for stomach inflammation were reduced, and in several cases, H. pylori was gone. 

However, in another Korean study, 20 people increased the amount of kimchi they ate from 60 g to 300 g a day, but all still had H. pylori 4 weeks later. They did see an increase in their “good” gut bacteria, though, and lower levels of some harmful enzymes linked to an unhealthy gut. 

There may also be links between eating kimchi and cholesterol levels.

For instance, one study showed that people who ate more kimchi had lower levels of “bad” LDL cholesterol and more “good” HDL cholesterol. 

While none of these studies are conclusive, they suggest that more research into the potential benefits of eating kimchi is worthwhile.

Recipe ideas

In traditional Korean cooking, kimchi features in every meal. It can be eaten as a condiment, mixed into rice, noodles, soups, and stews, or used to stuff dumplings. It can even add a tangy crunch to sandwiches.

Here are just a few ways you might like to try kimchi:

• kimchi fried rice

• kimchi dumplings (steamed or pan-fried)

• kimchi “jjigae” stew (with beef)

• spicy soft tofu stew

• kimchi pancakes

• kimchi with tofu (often eaten as a snack with a drink)

• kimchi with noodles (hot or cold)

• kimchi pasta

• added to vegetable dishes (like Brussels sprouts)

However, at ZOE, we know that there’s no one-size-fits-all approach to nutrition. Our research shows that everyone responds differently to food, so while one person may have good blood fat or blood sugar responses to kimchi pasta, another person may not. 

Take our free quiz to learn more about your individual responses to food.

Summary

Kimchi is a Korean dish of salted, fermented vegetables, often based around cabbage. It generally includes seasonings like garlic, chili, and ginger. It has a sour, salty, savory, and spicy flavor.

In Korean cooking, kimchi is eaten as a side dish or used as an ingredient in everything from rice and noodle dishes to dumplings and stews.

It can also be added to Western dishes like sandwiches, vegetable dishes, and pasta. 

Along with fiber, vitamins, and minerals, kimchi contains natural probiotic bacteria. If you eat them regularly, the probiotics in fermented foods can be beneficial to your gut microbiome.

Studies suggest that eating kimchi on a daily basis could help to improve some digestive problems. There’s also research linking kimchi to improved cholesterol levels. But more work is needed before scientists can draw any conclusions.

No two people have the same gut microbiome. To get a deeper understanding of your gut microbes and what foods suit your body, take our free quiz today.