Kimchi develops a unique flavor that is different from that of its original ingredients and condiments and becomes tasty as it ferments.
The osmotic pressure phenomenon, in which water exhausted, helps mature Kimchi. As a result, the green smell of vegetables disappears and necessary bacteria and enzymes are produced. This process determines the taste and smell of Kimchi.

Bacteria as well as condiments play an important role in fermenting Kimchi. Lactic acid makes Kimchi mature and an enzyme in combination with the organic elements of vegetables makes it tasty. It also prevents it from spoiling.
Salt, which prompts osmotic pressure, is used in all kinds of Kimchi to salt the vegetables and makes it taste good. Furthermore, it deactivates bacteria so that the Kimchi can be preserved for a long time.

Once salt penetrates into the vegetables, they dehydrate. The salt on the outside of the vegetables increases the osmotic pressure and enhances the permeability.
This function of salt applies not only to vegetables but also to other organic materials. Accordingly, the osmotic pressure of salt stops bacteria's activities, resulting in the their disappearance or the slowdown of enzyme.

Fermentation is caused mainly by bacteria in the Kimchi ingredients and, in particular, is controlled by the amount of salt and the temperature.
In summer, salty Kimchi (5% salt content) needs about 2 days, while ordinary Kimchi (3.5% salt content) requires one day to mature. However, during Kimjang season (when the temperature stays between 7 to 14C), salty Kimchi takes 10 to 18 days to mature, while ordinary Kimchi takes 5 to 12 days.

The higher the temperature, the faster Kimchi matures. Kimchi is most flavorful when it matures at a temperature of 5~10 degrees C for 2 to 3 weeks.
The appropriate salt concentration of the Kimjang Kimchi for winter is around 2~3%, while for spring and summer it is 4~5% and 5% respectively.
The sweet taste of Korean cabbages and radishes is lost if it is preserved with too much salt or if it is preserved for too long.

The amount of salt influences the reproduction of bacteria. In the initial maturing stage, lactic acid fermentation occurs as a result of the increased bacteria generating lactic acid.
The generated lactic acid and the salt prevent the vegetables from spoiling.

When it comes to the matter of producing Kimchi on a commercial scale, the preservation of Kimchi is the most difficult thing to resolve. Since Kimchi continues to ferment, it maintains the high balance of nutrition while maturing. After the peak of maturation, some bacteria continue to create an acid, which softens the fiber of the Kimchi and transforms the ingredients.

This chemical phenomenon is called the phenomenon of over-maturation and it is often found in long-preserved Kimjang Kimchi or in summer Kimchi.
In the late period of fermentation, an enzyme called polygalactulonaze decomposes pectin.
This chemical reaction softens Kimchi fiber. Polygalactulonaze rapidly increases as the external Kimchi juice is formed. The over-maturation of Kimchi is a challenging problem to be solved with regard to storage and distribution.

Kimchi, in general, has a good taste when properly matured, but it is easily acidified in response to high temperature and becomes inedible within two to three days. For this reason, the shelf life of Kimchi is quite limited without proper temperature control.

The best way to prevent over-maturation is to control the bacteria reproduction, while keeping the quality of the Kimchi unchanged, since over-maturation of Kimchi is caused by the action of bacteria.

Clay pots are usually used to preserve its contents from spoiling by circulating air through them. Crockery is made with a method of oxidation in which it is burnt through air and flame together. The pots can keep kimchi fresh for a long time. The shapes of the pots have developed differently in various regions. There are 2 main types of containers which are made of wood and earth. A crock jar terrace is usually located in the kitchen, an inner garden, or a rear garden surrounded with a stone fence. In the countryside, people usually buried the kimchi jar in the ground, covering them with a bundle of straw to protect it from snow and rain and to lessen the    temperature change.

from Kyonggi Province

from the Kyongsang Provinces

Kim Jang Season

Pumasi of KIMJANG

Pumasi is the Korean tradition of helping each other during the farmers' busiest season. Neighbors or relatives usually set up the schedule to help each other in turn. The Pumasi tradition is one of the living traditions that originated from the Korean spirit of community. All materials for Kimjang are prepared in advance. First you trim the cabbages. Then, you tear off the tough outer leaves and cut off the root of the cabbages. Then you put them into salty water for about 10 hours. During this time, Kimchi stuffing is made from condiments and trimmed radish. After cleaning them in water, put them in a wicker tray to drain and place the Kimchi stuffing in the vessel. Finally fill the cabbage leaves with Kimchi stuffing. Use the yellow inside leaves of the cabbage to wrap the Kimchi stuffing. The specific ingredients of Kimchi stuffing are sliced radish, parsley, mustard leaf, green onion, garlic, ginger, salted fish juice, rough salt, powered red pepper, and seaweed. Depending on tastes, Pyogo mushroom, raw oyster, raw shrimp, or fish can be added.

Maturing of KIMCHI Kimjang Kimchi becomes the most delicious when the temperature is kept at around 5 degrees. For the best result, Kimchi is preserved in the Kimchi storage area and the Kimchi jar is covered with a straw cushion. The jars are moved from time on the ground of the Kimchi storage. The straw cushion keeps out the cold and reproduces the bacteria, which make Kimchi mature. Korean farm families have individually owned their straw-fenced Kimchi storage in their backyard.

1. After cleaning the cabbages, cut them into 2 or 4 pieces.
   
2. Prepare salted water with a ratio of 2.5 cups of salt to 10 cups of water, then soak the cabbages in it for 6-8 hours.
   
3. Rinse the soaked cabbages in running water 3 times and then wait for them to dry a bit.
   
4. Cut dropwort, green onions, and radishes into lengths of 5 cm, then chop the garlic and ginger.
   
5. Prepare fish paste and add red chili pepper to it with sticky rice paste.
   
6. Wash oysters in salt water.
   
7. Mix the ingredients from steps 4, 5, and 6.
   
8. Put the mixture inside of each leaf then store in a kimchi pot. On the top, cover cabbage with a leaf and sprinkle some salt. Then place a heavy stone on top to compress it.

1. Pickled Seafood Paste
   Pickled sea food paste has 2 types:
   - fermented with only salt (pickled shrimp paste, pickled clam paste, pickled hair tail paste, pickled anchovy paste)
   - salt and other seasonings (pickled pollack roe paste, pickled squid paste, pickled gill paste, pickled spicy oyster paste)
   
   

   

   
   

2. Pickled Fish Paste (Sikhae)
   Sikhae differs from pickled sea food in that its materials are grains.
   Grains are matured with rice, malt, millet, and hot pepper powder or reddish shreds.
   
   
3. Pickled Fish Paste
   Unlike other paste, this pickled fish paste needs to be fermented longer (about 6-24 months). The longer the maturation period, the more active hydrolysis is on fish, achieving a pickled fish paste.

The number of specific kimchi types can not be easily counted. However, the Korean Food Academy has categorized over 100 different types.

The flavor depends on ingredients, condiments, the amount of salt, and level of spice used in each region. Korea's various regions produce different types of agricultural products, and this is reflected in each region's type of kimchi.

The southern provinces (North and South Cholla Provinces and North and South Kyongsang Provinces) tend to use more salt and seafood so the taste is stronger and sweeter. To the north, kimchi tastes less salty and is very mild.

This area's kimchi is stronger and spicier than other since it is mainly seasoned with pickled shellfish and salted anchovies.

Baech'u Kimchi with anchovies, Yak (medicine) Kimchi, O-i (cucumber) Kimchi, Kaji Kimchi, Goguma (sweet potato stem) kimchi, Goch'u Ip' (red pepper leaves) Kimchi, Dolgat (mustard leaf) Kimchi, Goldulbagi (Korean lettuce) Kimchi