Recipe for a Simple, Mild Kimchi

I recently published my recipe for a mild yet interesting sauerkraut, so I thought I'd share a similar recipe I have for kimchi as well. This one is focused on simplicity of preparation (while still maintaining precise control of the parameters) and mildness of flavor. If you're feeling more adventurous, I also have a more lively kimchi recipe you can check out.

Variables to be Controlled

Just like with the sauerkraut, there are three major variables I control: temperature, salinity, and surface area, and the approach to each is slightly different with kimchi.

Ambient Temperature

Like the sauerkraut, I like to start the first few days at around 65 °F (18 °C) to give the heterofermenters an ideal environment and impart a complex, bright flavor to the ferment. After that, I like to move it to the fridge, around 36 °F (2 °C) to let it slowly mature.

Brine Salinity

Perhaps the most glaring difference between this kimchi and the sauerkraut I mentioned earlier, aside from the sauce, is the way salt is applied to the cabbage. This kimchi involves a rinse step, whereas the sauerkraut does not. This begs the question: how much salt does the cabbage absorb? How does this affect the final salinity? I tend to estimate that the rinsed cabbage ends up at about 0.5% salinity, which is a low estimate. It's better to err on the side of adding slightly too much salt later on than to risk spoilage by under-salting.

We're also creating a sauce for the kimchi which contains fish sauce, and the amount of salt in the fish sauce is dependent on the specific fish sauce you choose. I recommend selecting a sauce with a known salt content.

Ingredients & Surface Area

The specific ingredients we add to the sauce can have profound effects on the result. Even the type of salt makes a difference.

The way you slice the cabbage also plays a role. In this recipe I recommend cutting the cabbage into 1-inch strips, but you can experiment with larger or smaller sizes. You can even try leaving the leaves whole.

By increasing the surface area you tend to make the early microbes more active by giving them better access to their food.

Recipe Details

Ingredients

~2 kg	Napa cabbage (2-3 medium cabbages).
2	pears or apples, peeled, cored, and quartered
2	yellow onions, peeled and quartered
15	garlic cloves, peeled
1	piece fresh ginger, 4 inches, peeled
~160 g	gochugaru or chili flakes
~180 g	fish sauce
6	green onions
2	carrots
Salt, not iodized, as needed.

Equipment

• Fermentation Vessel: 1 gallon capacity.
• Kitchen Scale, 1g resolution.
• Sharp knife.
• Wooden pounder.
• Mixing bowl.

Directions

1. Prepare the Storage Container

Choose a 1 gallon container of glass, ceramic, stainless steel, or food-safe plastic. Make sure it's clean. You don't need to completely sterilize it.

2. Prepare the Kitchen Scale and Mixing Bowl

Put the bowl on the scale and turn the scale on. Tare the scale so it reads "0" while the bowl is on it. Ensure the units are set to grams (g).

3. Dry-Brine the Cabbage

Dry-brine the cabbage at 5% salinity. Cut the ends off the cabbage, cut it into 1-inch thick ribbons, and weigh the usable part. If your scale reads 2115 grams, for example, that'd require about 106 grams of salt. You can read more about calculating salinity.

Measure the salt in a different bowl, then add it to the cabbage. Use your hands to massage the salt into cabbage. Make sure the salt gets evenly distributed. Set it aside at room temperuate for two hours.

4. Rinse the Cabbage

Transfer the salt to a colander and rinse the cabbage, tossing the cabbage as you do so. Drain the cabbage. Repeat this once or twice to get as much brine off the cabbage as possible. Allow the cabbage to drain well. Ensure the mixing bowl has also been rinsed.

5. Prepare the Aromatics and Sauce

Mince the pear, yellow onion, garlic, and ginger. Stir in the chili pepper flakes and the fish sauce of your choice. Cut the green onions diagonally into chunks, and add them to the bowl. Shred the carrots coarsely or cut them into matchsticks, add them to the bowl. Stir everything to combine well.

6. Calculate Salinity & Adjust Sauce

At this point we need to do a bit of calculating. We want to be able to reproduce the recipe accurately and consistently, and to do that we need to be able to control to salinity.

As I mentioned at the top of this piece, the rinsed cabbage ends up at about 0.5% salinity. We need to make sure that the salinity of the mixture rises to about 2% after we add the sauce.

First, if you used a commercial fish sauce, you can use the label to determine how much sodium was in the ~180 grams you used. It's important to note that sodium is not salt. Salt contains sodium (and also chlorine). The ratio of salt to sodium is 2.5:1 (the chlorine is heavier), so if you calculated (for example) 13.8 grams of sodium was in the amount of fish sauce you used, that's the equivalent of 34.5 grams salt.

Next, you need to weigh the sauce. Separately, you should also weigh the cabbage. Say the cabbage still weighs the 2115 grams from our example in step 3. Then, say the sauce weighs 1800 grams. Remember our estimate that the rinsed cabbage is at 0.5% salinity. That's ~10.5 grams of salt from the cabbage. We add that to the 34.5 grams of salt contributed by the sauce. Thus, in this example, we have 3915 grams of total material and about 45 grams of salt.

Therefore, at this point, the total mixture would end up at about 1.1% salinity after everything is combined. To make up for the missing 0.9% salinity, we add salt to the sauce:

3915 grams × 0.009 = 35.235 (~35 g) salt.

If you find that the combined mixture would be greater than about 2.5% salinity, I suggest adding a bit more pear, onion, carrot, and green onions until the math starts to work out.

7. Combine the Cabbage with the Sauce

Add the adjusted sauce to the drained cabbage. Mix it together with your hands until it's well combined and the sauce evenly distributed. If you're using whole leaves, you can spread the sauce on the leaves.

8. Transfer to the Vessel and Store

Fill the storage vessel with the mixture (and all its juices) and use your hands or a wooden pounder to gently pack the mixture down. You want to minimize the air in the mixture. You should also leave an inch or two of headspace at the top of the jar. Cover the jar with a lid, but ensure gas can escape. You can use a lid with an airlock, but I often just put the plastic screw-on lid on the jar without tightening it.

Leave the jar in a temperature-controlled area that stays around 65 °F (18 °C).

9. Ferment & Transfer to Cold Storage

After between 2 and 3 days of fermentation at around 65 °F (18 °C) the cabbage should have released more liquid. It's okay if the liquid still doesn't cover the cabbage. Move the kimchi to the refrigerator, where it will continue to ferment. It usually peaks in flavor complexity after a couple of weeks, and after that it'll develop a more rounded sour flavor that really accentuates the lactic acid.