Kimchi

What is it?

Kimchi is an iconic Korean recipe. There are hundreds of varieties of this traditionally fermented food. The most common variety is made from Napa cabbage which is called baechu kimchi. In addition to using salt and gochugaru (Korean chili flakes), cooks often flavor the traditional Korean side dish with garlic, ginger, and green onions.

Other recipes may use radish, cucumbers, zucchini, or even fruit as the base instead of cabbage. While spicy, hot gochugaru makes an appearance in most varieties.

What's in it?

The ingredients for cabbage kimchi are fairly simple, and freshness plays a critical role in both the dish's success and its flavor. You start by soaking cabbage in salt water. And then after draining away the excess liquid, you flavor the salted cabbage with a paste made of various aromatic ingredients such as garlic and ginger.

• Napa cabbage is the foundation of this recipe. The easiest way to prepare it is to chop the cabbage leaves into 1-inch pieces.
• Radish gives complements the cabbage and lends some texture to the dish.
• Garlic and green onions are alliums. They gives the salted cabbage flavor and a delicate, but potent sharpness.
• Ginger brings a little warmth to the recipe, and it partners well with chilis, garlic, and green onions.
• Gochugaru is a type of chili powder made from sundried chilis. It has a mellow heat level that builds, and sweet, smoky flavor. A staple ingredient in Korean cooking, you'll find it used in quite a few recipes.
• Fish sauce gives a salty, savory note. Fermented fish sauce or salted shrimp are a common ingredient in many versions of the recipe and they lend an elusive umami note to the recipe. Miso paste or Korean fermented soybean paste (doenjang) can also be used since they convey a similar savory flavor.

Is it good for you?

Like all fermented foods and drinks, kimchi is a functional food that is vibrantly rich in beneficial bacteria. These lactic acid bacteria support the immune system and digestive health.

Not only is it rich in good bacteria, but it's also a source of key antioxidants since it is made from cruciferous vegetables, ginger, garlic, and chilies all of which help support systemic health. As such, its rich nutritional profile likely contributes to the ways in which it supports cardiovascular, brain, and metabolic health as well as the immune system(1).

And while it's a functional food with loads of benefits, it's also incredibly easy to make at home.

How to make it

To make kimchi, begin first by soaking chopped cabbage in salt water. A few hours is sufficient, but if you have enough time to let it soak overnight, that's best. Soaking the cabbage in salt water allows helps to break down the cell walls, and gives it just the right amount of salinity for fermentation.

Blend up a spice paste of ginger, green onions, garlic, and Korean chili powder, toss the soaked cabbage in the paste until it's well-coated, and pack it into jars.

Traditionally, most kimchi recipes call for fermenting at room temperature and then transferring it to cold storage - such as a root cellar - to complete fermentation. This temperature is typically higher than your fridge, but lower than room temperature. You can simply keep it on your counter for a few days until signs of fermentation appear, and then tuck it in the fridge for a few weeks to age.

Recipe Tips

Like this homemade sauerkraut recipe and other fermented vegetables, kimchi is fairly easy to make at home. But, before you dive in, it's wise to keep a few things in mind.

• Use glass weights. Glass fermentation weights help to keep the cabbage submerged in brine as it ferments. And that means there's a lower chance that your ferment will develop mold or go bad. You can also tuck a cabbage leaf in the jar over the cabbage, to keep it safely beneath its salty brine.
• Use an airlock or fermentation seal. Part of the charm of kimchi is its fizziness, but if you prefer yours without the air bubbles, use an airlock or fermentation seal.
• Reserve the brine. The first step is to soak the cabbage in salt water. Save the brine to make the seasoning paste, and just in case you need a little liquid to cover your cabbage while it ferments.
• It ferments for only a few days (and then ages). Unlike other sour pickles and similar fermented vegetables which may ferment for weeks or months at room temperature, homemade kimchi typically only ferments a few days before you transfer it to the fridge to age. Large batches will need more time.
• Watch for signs of fermentation. Foaming and bubble formation are signs that healthy bacteria are at work and a good indicator that it's time to transfer it to the fridge.

Optimal Fermentation Conditions

Kimchi is one of many fermented cabbage dishes you'll find throughout the world. Other common cabbage ferments include sauerkraut and curtido. Unlike sauerkraut or pickles, where acidity is prized, the best kimchi is often much less acidic (2) - but still packed with flavor.

Traditionally, Korean home cooks prepared it by first soaking cabbage in salt, then combining the salted cabbage with garlic, ginger, chili, and other seasonings After letting it ferment a few days at room temperature (about 70 F), they'd bury the crock in the earth which kept it fermenting at about 50 F. That's about 10 degrees warmer than your fridge.

Now, special fermentation refrigerators are available to maintain those optimal conditions. That said, they tend to be difficult to find outside of Korea.

You can achieve that light acidity and optimally rich flavor by fermenting it for a few days at room temperature and then transferring it to the fridge to age for several weeks.

While researchers have found that just a few days at room temperature followed by a few weeks in the fridge at roughly 39F produced optimal flavor (3), the test kitchen team at America's Test Kitchen disagreed. They found a temperature of about 65 F - or the temperature of a cold room - produced the best flavor (4), likely demonstrating the difference between traditional Korean kimchi-making and its Americanized counterpart.

Accordingly, it might be worth making a few batches to experiment so that you find the right flavor for you.

Kimchi is also fizzy. Carbon dioxide builds up during fermentation as bacteria break down complex sugars and starches. An airlock, used with many fermented foods, allows that carbonation to escape.

You'll want to keep the carbon dioxide inside your jar so it becomes effervescent and bubbly. It's a similar practice that homebrewers use to make fermented drinks like water kefir or kombucha fizzy. So seal your jar tightly with a plain lid.

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Recipe Questions

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References

1. Park, K.Y., et al. (2014) Health benefits of kimchi (Korean fermented vegetables) as a probiotic food. Journal of Medicinal Food.
2. Steinkraus, K.H. (1992) Applications of Biotechnology to Fermented Foods: Report of an Ad Hoc Panel of the Board on Science and Technology for International Development. National Academies Press.
3. Patra, J. K., Das, G., Paramithiotis, S., & Shin, H. S. (2016). Kimchi and Other Widely Consumed Traditional Fermented Foods of Korea: A Review. Frontiers in microbiology, 7, 1493.
4. Cardiff, E., Davison, J.C., (eds) et al. (2016) Foolproof Preserving: A Guide to Jams, Jellies, Pickles, Condiments & More. America's Test Kitchen.