The generic term for Korean fermented vegetables, kimchi is traditionally prepared as an annual event at kimjang, prelude to the winter months when fresh vegetable supply is limited. I first learnt how to prepare homemade kimchi in the Matthew Kenney course for his signature dish of raw kimchi dumplings. It was surprisingly easy, although the first attempt was marred by erroneous inauthenticity with respect to the preparation method and a result that vaguely resembled the traditional Korean kimchi I was familiar with. Propelled by a sudden fascination of fermented foods, I delved into books, online resources and materials, hungry to learn about the art and science of making kickbutt kimchi. And now three rounds of kimchi making later, I hereby present what I have gleaned along the way.
Kimchi may have started out as a simple salted vegetable back in 3rd or 4th century A.D. Red chili peppers, known as gochugaru, were a relatively recent addition, only introduced in 17th century by Portuguese traders. The introduction and lasting adoption of gochugaru is testament to how much it enhanced the taste. It is hot and sweet with smoky notes but is not as hot as many of the Latin American chili varieties – typically in the range of 1,000 to 1,500 Scoville units.
Varieties of kimchi are numerous and classified based on season – winter or summer – which in turn influence the choice of ingredient. The most prevalent types of kimchi are baechu (napa cabbage) kimchi, radish kimchi, fruits and roots vegetable kimchi and namul (seasoned vegetables) with the option of adding gochugaru. Furthermore, each family of kimchi can be prepared by a number of ways and cuts e.g. whole, wrapped, cubed or shredded; and as ordinary (without water) or as mul-kimchi (in water). Today I am sharing with you the recipe for mat-baechu kimchi which is ordinary cut napa cabbage kimchi. This is the most popular and traditional kimchi and found at all banchan.
Salt concentration and temperature are the key factors for controlling kimchi fermentation. According to a journal article (Mheen 2003), the best taste of kimchi is attained with 2-3% salt concentration at 20°C after 2-3 days of fermentation. If the salt concentration is below the optimum, fermentation proceeds too quickly and can cause excessive acidification and softening. On the other hand, when salt concentration is over 5%, the kimchi would be too salty and have poor colour and flavour. The temperature affects the optimum ripening time for kimchi. At 30°C (Singapore weather), the optimum ripening period is 1 day. At lower temperatures, the optimum ripening time increases.
The type and quality of raw materials that go into the kimchi is another factor that affects kimchi fermentation. These include the major raw materials, sub-ingredients (spices) and optional (minor) ingredients. The major ingredient for mat-baechu is baechu or napa cabbage. Choose compact structure, oval-shaped head, white tissue and green leaves. Among the sub-ingredients, gochugaru, ginger, garlic, green onions and radish are most common. Minor ingredients include fermented anchovy and shrimp and cooked glutinous rice flour. The functions of the raw materials for baechu kimchi are summarised as below:
- Baechu (napa cabbage): major ingredient
- Gochugaru: spiciness, color intensity
- Ginger: adds hot spicy flavour
- Garlic: which delays LAB fermentation and reduce acidification due to allicin
- Green onions: delay LAB fermentation and reduce acidification due to allyl sulfides
- Radish: filler for spice mixture
- Fermented seafood: protein and amino acid source, promotes fermentation and contributes unique taste
- Glutinous rice paste: carbohydrate source, promotes fermentation
Sources that promote kimchi fermentation were reported as gochugaru, radish, fermented seafood and starches. Those that have delaying effects were reported as garlic, leaf mustard and alliums. Ginger had controversial effects on kimchi fermentation. On garlic, alliin is changed to allicin which has an intensive taste. Allicin takes part in fermentation of kimchi by inhibiting the growth of unnecessary microorganisms and slows the fermentation of kimchi. Garlic improves the storage capacity by prolonging the LAB fermentation period and results in less acidification. With fermentation of kimchi, the intensive hot taste of garlic slowly changes to a harmonised taste and flavor, so garlic haters need not be wary.
In my raw vegan version, most of the traditional components are retained. The only substitutes made are dulse flakes and sesame seeds to replace fermented fish as they are similarly high in umami and protein; and carrots to replace glutinous rice paste as a carbohydrate source.
- 1400 g (1 head) Napa cabbage
- 4-5 tbsp coarse Himalayan salt (2-3% by weight)
- 140 g (1 large) carrot, julienned
- 1/4 head red cabbage, julienned
- 1/2 red bell pepper, julienned
- 3-4 scallions, sliced
- 6 cloves garlic, minced
- 2 tbsp ginger, sliced
- 2 tbsp white sesame seeds
- 1 tsp dulse flakes
- 48 g (1/2 cup) gochugaru (Korean red chili flakes)
- Separate and wash cabbage leaves thoroughly. Cut into squares. Sprinkle salt onto cabbage. Massage firmly to collapse cell walls and release liquid to form brine. Set aside for 2 hours. After 2 hours, rinse the cabbage with water to remove excess salt before combining with the seasoning paste.
- Create a seasoning paste with the scallions, garlic, ginger, sesame seeds, dulse flakes and gochugaru. You can use either a mortar and pestle or food processor to create the paste.
- To the washed and drained cabbage, add in the remaining vegetables (carrot, purple cabbage, bell pepper, and toss until well combined. Wearing gloves or with very clean hands, rub the seasoning paste into the vegetables mixture.
- Transfer the vegetables to a clean quart glass container and use a clean fist or utensil to compress mixture. Ensure all contents are submerged under brine to prevent spoilage. Leave about 5 cm of room at the top of the bottle before capping it tightly with a lid. Allow to ferment at room temperature for 3 days, You may need to “burp” your kimchi every 24 hours to release some of the pressure from fermentation. After 2-3 days, your kimchi is ready to eat. Transfer to the fridge and use as needed. The kimchi will continue to ripen in the fridge, and will keep well in the fridge for a couple of weeks.