While the cabbage is close to being ready, prepare the red pepper sauce. In a medium bowl, mix kochukaru (red pepper flakes), water, saewoo jjut, fish sauce, green onions, sugar, ginger, garlic, rice flour paste, and about a 1/2 cup water. Mix thoroughly. Taste. It should be balanced – not too salty, not too fishy, not to spicy and not too sweet. Adjust seasonings at this point. The consistently should be akin to very thick batter. Add a bit more water if necessary. Mix in carrots and radish. Set aside.
Once the cabbage is ready (the volume of the cabbage should have decreased, and it should be a bit wilted), rinse the cabbage under cold running water and let drain in a colander. Once drained, place the cabbage in a large bowl.
At this point you may want to put clean plastic gloves on especially if you have sensitive skin. Add the sauce to the cabbage. Thoroughly mix the sauce and cabbage and make sure every piece of cabbage is coated with the red pepper sauce. Taste. If it needs more salt, add a bit of fish sauce. But you don’t want it to be too salty.
Transfer the cabbage mixture into a large glass jar. Press down on the cabbage as you are filling the jar. Leave about 1-inch of space from the top.
Don’t throw the empty bowl in the sink just yet. Pour in about 1 cup of water into the bowl. Add about a teaspoon of salt to start, and stir. Swirl the water around to make sure you get all the remaining pepper mixture. Taste. Again, you don’t want it too salty – just a hint of salt. Fill the jar with the water until it barely covers the cabbage.
Press down on the cabbage again and make sure the liquid has made its way throughout the jar. Close the lid tightly.
Leave the jars at room temperature** for about a day away from direct sunlight. I leave mine out for about 24-30 hours. This is when the magic happens. You may want to place the jar in a shallow bowl or plate in case there is leakage.
After those 24 or so excruciating hours, sample the kimchi. There should be a slight tang. At this point it is ready to be refrigerated. You can eat the kimchi right away, but I prefer to wait at least a week to indulge. The kimchi will continue to ferment at a much slower pace in the refrigerator and will keep for about 4 weeks. The kimchi will turn really sour at this point and if you have any left in the jar, it will be perfect for jigae, fried rice, ramen or jun.