
Cut each napa cabbage in half and make an incision in the core. Remove any tough or bad outer leaves.
In a large bowl, dissolve 2 cups of sea salt in 3L of water to make brine. Dip the prepared cabbage halves in the brine. Place them into a large kimchi bag. Sprinkle 1.5 cups of sea salt into the core area of each cabbage. Pour the remaining brine into the bag, tie it securely, and let it salt for 10 hours. Flip the bag after 5 hours for even salting.
After 10 hours, remove the salted cabbage and rinse thoroughly 3-4 times in water. Place the rinsed cabbage on a rack to drain excess water for 1.5 to 2 hours. (If making a large batch, you can drain for half a day or longer.) Cut off any overly thick stems and gently squeeze out excess water.
First, combine 200ml of water and 25g of glutinous rice flour in a measuring cup, mixing until dissolved. In a pot, bring 800ml of water to a boil. Once boiling, quickly pour in the glutinous rice flour mixture while continuously stirring to prevent it from sticking. Stir occasionally until it boils vigorously. Turn off the heat and let it cool to room temperature.
In a large bowl, add 300g of red pepper powder, 120g of minced garlic, 20g of ginger syrup (or 10g of minced ginger), 20g of sugar, 55g of sea salt, 2 pinches of Miwon, and the cooled glutinous rice paste. Mix thoroughly to make the seasoning. Let the seasoning sit for 10 minutes. After 10 minutes, add 3 heaping tablespoons of sesame seeds and mix well again.
Now, put on gloves and spread the seasoning evenly over each leaf of the salted cabbage. It's important to apply it not just on the thin leaves, but also thoroughly on the thick stems near the core for a more delicious kimchi. After applying the seasoning, neatly gather the ends of the cabbage and wrap it with two outer leaves to secure it.
Place the seasoned kimchi into a kimchi container, packing it tightly. Cover the top of the kimchi with a green outer leaf coated in seasoning. Let it ferment at room temperature until it reaches your desired taste, then store it in a kimchi refrigerator. If you plan to store it for a long time, you can put it directly into the kimchi refrigerator.