Making & Storing Kimchi
The process of making and storing Kimchi in Korea is called kimjang. It is really a year long process and an ancient tradition that is still going strong today. Each season of the year means a different kimjang activity. Foods needed for the making of Kimchi are gathered in their seasons and stored until the late fall when the Kimchi is made. Green chilies, garlic and pickled fish are gathered in the spring. Red peppers are gathered in September and dried, ground and stored.
Kimjang season officially begins in November, when kimjang markets pop up everywhere across the country. Massive harvests of cabbages, radishes, green onion and Indian Mustard Leaves await customers by the truckload at these markets during November and December.
Kimchi Main Ingredients
With over 200 different varieties of Kimchi in existence today, there is certainly room for variety in ingredients, but the basis and method is generally similar across all recipes. The main ingredient is normally cabbage or radish, but can be a variety of different vegetables, with root vegetables and brassicae being the most common. Next, there are the seasonings, which is where personal preference really comes into play. The traditional seasonings are hot red chilli pepper flakes (and lots of them), garlic, ginger, scallions or green onions and fish sauce. Pickled fish, squid, oysters, octopus or anchovies are sometimes used instead of fish sauce. The cabbage is soaked in a brine solution, which is simply sea salt and water to preserve it and start the fermentation process.
Cabbage – Napa, Chinese, Korean or Celery Cabbages are the most common varieties of cabbages used. Cabbage is higher in protein than most vegetables and is also high in vitamin C. The darker green leaves are high in vitamin A, so those should not be stripped away.
Radish – Korean, Japanese and Pony-Tail radishes are the main three types of radishes used in Kimchi. While the root part of a radish is the most commonly used part of the plant, the stalks and leaves are also very tasty and nutritious. The Root is the tangiest part, and is the main part used for diced Radish Kimchi. The leaves are much milder and the middle part of the stalk is quite sweet. Radishes are high in Vitamin C, carotene, calcium and diastase.
Green Onions – Either Green Thread Onions or Chinese Onions are used in Kimchi. The Green Thread variety is firmer and resistant to spoilage, so it is usually used in winter Kimchi, while Chinese green onions are used more for summer Kimchi, as they spoil much faster.
Red Chili Peppers – No Kimchi is complete without a hefty dose of hot red chilies! They are what give Kimchi its spicy flavor and beautiful red color. Peppers are higher in vitamin C than most vegetables, and they are also rich in carotene and vitamin B. Red pepper strips can be used as a garnish as well.
Indian Mustard Leaves – These are available in green or a reddish color. Both are used frequently. The green leaves are used more in White Kimchi, while the red ones are used in Whole Cabbage and Radish Kimchi. Indian Mustard Leaves are high in calcium, iron, Vitamin A and Vitamin C, making them a valuable health food.
Korean Watercress – Both the leaves and stalks are used in most varieties of Kimchi. It is high in calcium and vitamin A and C.
Sponge Seaweed – Fresh or dried seaweed adds a cool, crisp taste to any kind of Kimchi and is a good source of calcium and iodine. It is recognized to be beneficial for heart health.
Garlic – Almost a super food, garlic is a well-known health food that should be part of everyone’s diet for its digestive benefits, cancer-fighting effects and antibacterial properties. Garlic is a must in all Kimchi preparations.
Ginger – Ginger gives an unmistakable poignant taste to any dish, and Kimchi is no exception.
Salt – The catalyst for fermentation and preservation of Kimchi, salt is essential in all recipes.
Pickled Fish – Shrimp, corvina, or anchovies are frequently used in many Kimchi recipes.
You may have been eating Kimchi all your life or perhaps you are just now learning about this amazing food for the first time. Regardless, if you have not done it before, the idea of making Kimchi on your own may sound daunting to many people, especially to Westerners.
Making Kimchi, however, is a fairly straightforward process that has remained fundamentally faithful to its original techniques since its inception. The important aspect of making Kimchi is the fermentation of the vegetables. Salt is the catalyst to perfect fermentation. With just the right amount of salt, lactic acid and probiotic bacteria begin to form and fermentation will happen naturally. With not enough salt, the vegetables will break down and eventually rot and with too much salt, all bacteria will be killed and it will not ferment. The ideal salt concentration is around 3%, and the ideal storage temperature is about 50 degrees. Using lots of salt in the brine and rinsing the cabbage thoroughly after brining will ensure that you have just the right amount of salt.
The general process is to cut your vegetables, usually Chinese or Napa cabbage or radish, into chunks and soak it in salt-water brine for a few hours. Then you thoroughly rinse the cabbage and place it in a bowl and add the red pepper paste, which is simply red pepper flakes and water; garlic, ginger, scallions and fish sauce. The mixture is then bottled and left to ferment unrefrigerated. You can expect to let you Kimchi sit for about two days. The longer the time of fermentation, the sour your Kimchi will get. Then you can put your Kimchi in the refrigerator where it will continue to ferment and age.
This is where some westerners will balk and resist the idea of leaving food out at room temperature to ferment. While meat can definitely not be left at room temperature for very long, and North American pickling and canning processes require boiling and holding at a high heat, Kimchi, like sauerkraut and other fermented foods, NEED to be left out to begin the fermentation process. The result is an amazingly healthy food for you. Don’t worry – Kimchi is very easy to make and will turn out fine on the first try with proper care and recipes.
Science Behind Kimchi Making
The primary function in creating Kimchi and determining the flavor and aroma of it is called the osmotic pressure phenomenon, which is the process of water evaporation, whereby the essential enzymes and bacteria are formed.
The essential compounds that initiate fermentation are bacteria, lactic acid and enzymes. These items are what prevent spoiling and what gives Kimchi its distinct taste. Salt not only gives flavor, but also activates the osmotic pressure, kills harmful bacteria and controls the fermentation process. As salt permeates the vegetables, they soften and dehydrate and osmotic pressure increases, slowing bacterial and enzyme activity.
Temperature also plays an essential role in the fermentation process. The temperature and amount of salt determine the length of time the Kimchi needs to mature. In the summer, Kimchi with a 5% salt content will take two days to mature and less salty Kimchi with 3.5% salt will be ready in one day. In the fall and early winter, during Kimjang, 5% salt Kimchi will take 10 to 18 days and 3.5% salt Kimchi will be ready in 5 to 12 days.
Preservation of Kimchi can be challenging in commercial applications as Kimchi continues to ferment until it is eaten. Even after it is mature, bacteria continues to work and create acid which slowly breaks down the Kimchi. This is referred to as over-maturation when an enzyme called polygalactulonaze breaks down the pectin and softens the Kimchi.
Traditional Kimchi is made in a large bowl and then stored in large clay pots to ferment in a cool area, often underground. Because the most critical factor in creating the Kimchi’s unique exquisite and refreshing taste is the fermentation condition, of which the fermentation temperature is one of the key aspects, the storage temperature must be well controlled in order to avoid over fermentation and keep its delicious taste last long. For this reason, prior to the invention and introduction of a refrigerator, Kimchi often times used to be stored in clay crocks underground where the underground temperature is cooler and maintained more stably.
Today, most people put it in large jars and let it ferment at room temperature for anywhere from a few hours to a few days and then store it in the refrigerator. Kimchi isn’t generally too sensitive to the container; you can use a glass jar, Styrofoam box, steel container, or even plastic container. However there are specialized fermentation vessels made for fermented food specifically such as Kimchi you may want to consider. They can improve and keep the taste longer. One of the recommended fermentation crocks is Harsch crocks, which has a water lock on top that seals in the smells inside and seals out the air. In Korea, there are even refrigerators that are made specifically for storing Kimchi and in recent times it is widely common during Korean households to own two refrigerators, one for Kimchi and the other for everything else.
The important thing to remember in choosing your storage container is that it has a tight seal and lets no oxygen in. CO2 gas will be created during the fermentation process and the contents of the jar will be slightly bubbly when you open it. Once opened, you can store Kimchi in the refrigerator for up to a month. Of course, it is another matter entirely how long you can keep yourself from reaching the bottom of the container, depending on how addicted you are!
Things to Watch Out (When Making Kimchi)
Mold – Mold is caused when the moist vegetables are exposed to the air. Mold can be prevented by ensuring that the vegetables remain completely submerged in the brine liquid, keeping a tight seal on the containers and maintaining the correct level of salt and acid.
Flies – Vinegar flies can be a problem with fermenting foods. Again, a tight seal on the containers will keep this from being a problem.
Soft, Mushy vegetables – Fermenting too long at room temperature can soften the vegetables. Leave at room temperature for no more than two days and then move the Kimchi to a cooler area.
Off Taste – Kimchi should have a pleasantly sour and spicy flavor and smell. If it smells bad, harmful bacteria may have been introduced at some point and it is best to throw it away.
Food Poisoning – The only way this could happen is if you cross-contaminated the Kimchi with meat somehow. Keep utensils, surfaces and your hands clean and sanitized while making Kimchi and you will never have to worry about food poisoning.