If properly stored, kimchi can last up to 6 months. However, there are many variables to consider in order to determine the shelf life of your kimchi, such as the storage conditions, the ingredients, and the number of times the kimchi jar has been aerated. We will teach you everything you need to know about the timing of your kimchi, including the ideal fermentation and how long it is generally safe to eat..
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Why Koreans made fermented vegetables with long shelf life
Kimchi has a rich and long history. While nowadays, people mostly appreciate its flavor, back in the 1st century BC, Koreans cherished it for its long shelf life. Korean winters back then were long and difficult. To get by through tough months, families used preservation methods to keep a constant supply of nutritious foods. Kimchi literally translates to “salted vegetables,” and that’s exactly what Koreans began doing when cabbage first arrived in Korea.
While kimchi already lasted for a long time, it was still very different from the kimchi we know today. That all changed in the 16th century when chilis were first imported from the American continent. The invention of the fridge and freezer have greatly improved our preservation abilities. However kimchi is still gaining lots of popularity in recent years.
Kimchi shelf life and fermentation time
There is no such thing as the perfect fermentation time. There are simply too many factors that affect the metabolic rate of the probiotic bacteria inside your kimchi. Additionally, fermented kimchi is purely a matter of taste. Some enjoy pungent, carbonated kimchi that has been fermenting for weeks. Others don’t go crazy over the taste of lactic prefer mild kimchi. While you probably already know your taste preference, you may not be aware of the various variables that can affect the rate of reaction inside your kimchi jar.
Factors influencing how long your kimchi will last
The salt content of your kimchi
Salt will slow down the rate at which your kimchi is fermenting, thus making it last longer. If you would like your kimchi to ferment faster, you can reduce the sodium content by scrubbing off excess salt after dehydrating your main vegetable (e.g., napa cabbage). Kimchi with a high-salt content of 7% stored at 5℃ seemingly lasts a lifetime since even 180 days of fermentation didn’t ripen it.
Storage temperature
The ambient temperature is the second most decisive factor when it comes to how long your kimchi lasts. Kimchi can be fermented from 4℃ to 30℃. If you make kimchi frequently, it is essential that you ferment at a consistent temperature. This way, you have a controlled variable and continuously optimize from batch to batch until you have found the ideal recipe and fermentation time for you!
Ingredients
There are hundreds of types of kimchi, each with dozens of variations incorporating different fruits, vegetables, seasonings, and condiments. The table below shows some of the most popular sub-ingredients and whether they make your kimchi last longer or shorter.
| Ingredients that slow down fermentation | Ingredients that speed up fermentation |
| Sugar | Salt |
| Garlic (the most common ingredient) | Proteins |
| Leek | Anchovy |
| Mustard | Starches (like glutinous rice flour) |
| Vinegar | Shrimp |
| Pepper flakes |
Aeration
How tightly you screw the lid of your kimchi jar and how frequently you open it also affects how long your kimchi keeps. Sometimes pressure will build up in your jar, due to the carbonation caused by the lactobacillus producing CO². Aerating kimchi more frequently will make the kimchi taste less fizzy and boost the fermentation rate. An airlock jar will remove carbonation without necessarily speeding up fermentation.
How long to let kimchi ferment at room temperature
Kimchi at room temperature is typically fermented for 2-4 days. However, if you used a lot of sugar in your Kimchi recipe, you may decide to give it a little taste after 24 hours. Also, ensure that you let it ferment in a dark place to make it last longer. After you first open your jar, we generally recommend placing it in the fridge. However, if you don’t have space to refrigerate your bulky kimchi jar, you can keep it at room temperature for about a week.
How long does Kimchi last in the fridge?
If you want to avoid your kimchi going bad, you should place it in the refrigerator. Kimchi in the fridge won’t go bad for a few months. During these times, it will still ferment but at a much slower rate. If you prefer mild kimchi, made a big batch, or eat kimchi irregularly, we highly suggest refrigerating your kimchi right from the get-go to make it last the longest. It will still taste just as good as kimchi fermented at room temperature, but slowing down the fermentation rate.
Does kimchi go bad in the fridge?
People’s tastebuds vary, and so does their definition of “bad”. If you prefer crunchy kimchi that doesn’t taste too astringent, acidic, or fizzy, you should eat it within the first three months in the fridge. If the kimchi itself is too sour for you after three months, you may also decide to incorporate it into various heated dishes to mellow its taste.
How to store kimchi in the fridge
There is a major problem with conventional refrigerators that makes them less than ideal to make kimchi last. Virtually all standard refrigerators regulate temperature using an indirect cooler system. In other words: The back of the fridge provides the cooling effect. Thus fridges rely on air circulation to spread the cold air around the fridge. Unfortunately, fridges tend to have poor air flow by design. A single fridge can have a temperature gap of 10℃. This can cause the temperature inside your kimchi jar to fluctuate, which irritates the fermentation process. These irregularities mean that you can never assume that the kimchi inside your fridge will last more than a few months.
If you want your kimchi to last as long as possible, you should lower the temperature of your fridge (i.e., setting it to max performance). You can also free up some space in your fridge’s vegetable compartments and place the kimchi jar there. This section is usually isolated with glass walls, thus allowing for a more stable temperature. This is especially important if you open your fridge multiple times a day.
Kimchi refrigerators provide better temperature control
If you want to make kimchi slowly ferment and last for as long as possible, you may want to consider getting a kimchi fridge. These refrigerators focus on the preservation of fermented foods. They are typically equipped with multiple sensors to measure temperature, humidity, and the frequency of opening the door. This enables them to maintain optimal conditions to help make your kimchi last much longer. In addition, they also have fermentation functionalities, where you can raise the temperature to speed up the metabolism of lactic acid bacteria inside your kimchi jar. Another problem with mature kimchi is that it quickly stinks up your entire fridge. Some kimchi fridges have deodorization technology, which helps eliminate odors and germs.
| Kimchi type | Shelf life at room temperature | Shelf life inside the fridge | Shelf life inside kimchi fridge |
| Sweet kimchi (with lots of added sugar or fruits) | 4-5 days | 1-2 months | 3 months |
| Salt-free kimchi | 4 days | 1-2 months | 3 months |
| Traditional napa kimchi | 7 days (maybe longer if unopened) | Around 3 months | 6 months+ |
| Kimchi with lots of salt and vinegar | 7 days+ | 3 months+ | Unknown |
| Low carb kimchi | 7 days+ | 3 months+ | Unknown |
How to avoid kimchi from going bad and how to spot bad kimchi?
Although it is quite rare, spoiled kimchi can develop mold. Mold contains various mycotoxins, which lead to severe illness. While mold is the most prominent danger, there are also plenty of others, such as botulism, salmonella, E. coli, or regular food poisoning. Nevertheless, these dangers should not deter you from making kimchi; just be sure to adhere to proper sterilization and storage tips.
Proper hygiene and preparation make kimchi last longer and reduces the risk of contamination.
Washing and sterilizing your jar
Before you begin making kimchi, you should first prepare your kimchi jar by thoroughly washing it with dish soap, rinsing it, and then sterilizing it. The easiest way to sterilize your kimchi jar is by filling it to the brim with boiling water. Although the lid should never touch your kimchi, you should still sterilize it as well.
Submerging kimchi in brine
When you fill your glass jar with kimchi, always make sure it is topped with your seasoned brine. Compress the kimchi towards the bottom of the jar using a spatula. If you don’t have enough brine to submerge all your vegetables in brine, you may want to consider adding some vinegar.
Using sterile utensils
Curiosity gets the better of you, and you want to take a peek and have a taste? No problem. Just make sure to use a sterile fork to have a bite and try to limit the frequency at which you open (and thus aerate) your kimchi jar to make it last longer.
How to spot bad kimchi
If you’ve made kimchi before, it will likely be easily noticeable if your kimchi is spoiled. You may want to dump your kimchi if it:
- … smells off. (not in the way pungent kimchi does, but even worse!)
- …has any fuzzy black, blue, white, or green masses on the surface, sides, and bottoms touching the glass or at the center
- …it is very dry
- …was made in a non-sterile container
- …was subjected to contaminated air
- …came in contact with contaminated cutlery
- …smells or tastes like alcohol
If you suspect that your kimchi is spoiled, please be careful and examine it thoroughly from all sides.
