How to make it
How to make napa cabbage kimchi at home, safely
Salted napa cabbage tossed with a chili, garlic and ginger paste, fermented for a day or two and then kept cold. A university extension recipe with the safety checks built in.
By the editors of Alimentotherapy Last reviewed 6 min read Not medical advice
- Makes
- About 1 gallon (from 2 heads of napa cabbage)
- Hands-on
- 1 1/2 hours
- Total time
- 1 to 4 days, plus 3 to 6 hours salting
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The short answer
Salt chopped napa cabbage for 3 to 6 hours, rinse, toss with a paste of garlic, ginger, Korean red pepper and rice flour, then ferment at about 68°F for 1 to 2 days until it reaches pH 4.6 or below, as Colorado State University Extension’s recipe sets out Colostate. On health, our fermented foods page grades the evidence as limited: a fermented-food diet raised gut microbe diversity in one small trial Wastyk 2021, and there is no reason to expect kimchi to act as a medicine.
Ingredients and method
Ingredients
- 2 medium heads napa cabbage (about 6 to 8 pounds total)
- 1 1/2 cups coarse non-iodized salt, divided (1/2 cup for the soaking brine, 1 cup for salting)
- 1 gallon plus 1/2 cup cold water, divided
- 2 tablespoons sweet rice flour
- 1 to 10 cloves garlic, to taste
- About 3 slices fresh ginger (0.2 to 0.4 oz)
- 1 cup Korean red pepper powder (gochugaru, sold for kimchi)
- 1/2 Korean radish or daikon (about 1 to 1 1/2 pounds)
- 10 green onions
- Optional: 1 Asian pear; 1 teaspoon fish sauce; up to 2 teaspoons fine salt, only as needed
Equipment
- Very large glass, plastic or stainless steel mixing bowl
- Colander
- 1-quart saucepan for the rice flour paste
- Food-safe glass or plastic containers with tight lids, big enough for 2 cabbages (no metal containers, no cracked or chipped earthenware)
- Disposable food-handler gloves (the chili powder burns skin)
- pH test strips reading 3.0 to 5.5
Prepare the cabbage
Rinse the heads under cold water and drain. Cut away any spoiled or damaged spots. Quarter each head, remove the cores and chop into 2-inch pieces.
Dip in brine
Stir 1/2 cup coarse salt into 1 gallon of cold water in a large bowl. Dip the cabbage pieces in briefly to help the salt penetrate, then drain and discard this brine.
Salt for 3 to 6 hours
Sprinkle 1 cup coarse salt over the cabbage and massage it in well. Cover and leave at room temperature for 3 to 6 hours; the longer it sits, the saltier the kimchi.
Rinse and drain
Rinse the cabbage 3 to 4 times in cold water to wash off the salt, then drain in a colander for at least 30 minutes.
Make the seasoning paste
Stir the sweet rice flour into 1/2 cup water in the small pan, bring to a boil and let it cool. Mince the garlic and ginger finely (or blend with a little water), mix into the cooled rice paste and add the red pepper powder.
Cut the vegetables and combine
Peel the radish and Asian pear if using; trim the green onions. Cut all into 1-inch matchsticks. Wearing gloves, mix the paste with the vegetables, then the fish sauce if using. Add fine salt only if needed. Rub the paste through the cabbage and mix thoroughly.
Pack
Pack the kimchi tightly into the containers to push out air and encourage brine to form, filling each only about two-thirds full because fermentation releases gas. Put lids on without overtightening so gas can escape. Stand jars on a plate to catch overflow.
Ferment and test
Either refrigerate it to ferment slowly over 3 to 4 days, or leave it in a well-ventilated spot at a steady room temperature, ideally around 68°F, for 1 to 2 days. Test daily with a pH strip until it reads 4.6 or below.
Store cold
Keep the kimchi covered and pressed down in the refrigerator. It grows more sour over time; extension guidance says it is best eaten within 1 to 2 weeks.
If you need the equipment
About this recipe
There are hundreds of kimchi variations. This page follows a baechu-style napa cabbage kimchi from Colorado State University Extension, written with a local kimchi maker and the university’s food science staff, because it gives tested quantities and a safety endpoint Colostate. Unlike sauerkraut, no starter is needed: the lactic acid bacteria that ferment kimchi are already on the raw vegetables Oregonstate.
In the kitchen
Summer napa cabbage tends to be softer and ferments faster; winter cabbage is firmer and may need more timeColostate. Choose light-green, compact heads that feel heavy for their size.
Salt, pH and time: what keeps it safe
Brining draws water out of the vegetables, helps preserve them and lets the seasoning penetrate. Oregon State University Extension puts the final salt concentration of kimchi at 2 to 5 percent, and the optimum pH, reached as the bacteria make lactic and acetic acid, at about 4.2 Oregonstate. The safety threshold is a little higher: Colorado State says kimchi should reach pH 4.6 or below before you eat it, and recommends checking with a test strip Colostate.
Kimchi ferments much faster than sauerkraut. Oregon State says one to two days at room temperature, or more slowly in the refrigerator, and advises keeping it refrigerated and eating it within a week for best qualityOregonstate. Colorado State gives three to four days for a fridge ferment and up to two weeks for refrigerated storage Colostate. Where the two differ, the shorter limit is the cautious one; quality, not only safety, declines as kimchi keeps souring.
What kimchi can and cannot do
Fresh, unheated kimchi carries live bacteria from the ferment. The best human evidence for fermented foods in general is a 17-week Stanford trial: healthy adults randomized to a high-fermented-food diet (18 per group) showed steadily increasing gut microbiota diversity and falling inflammatory markers Wastyk 2021. That is one small trial with mixed ferments, which is why our fermented foods page grades it limited. Think of kimchi as a flavorful way to eat more vegetables. Our kimchi vs sauerkraut comparison sets the two side by side.
Salt, tyramine and buying it ready-made
Kimchi is salty, and fish sauce and fermented condiments are among the foods a 2018 review examined for tyramine content. The same review credits starter cultures and hygiene rules for the low tyramine content of most modern commercial foods Gillman 2018, controls a home ferment does not have. If you take an MAOI, follow your prescriber’s list and see tyramine and MAOIs.
If you would rather buy kimchi, check the label for whether it is refrigerated and unpasteurized, if live cultures matter to you. iHerb lists kimchi and Korean chili powder if your local store does not carry gochugaru.
Food safety
- Do not eat kimchi until it reaches pH 4.6 or below; check with a test strip rather than by taste or smell.
- Keep it refrigerated once fermented, pressed down under its liquid, and discard it if you see surface mold.
- Use glass or food-grade plastic. Avoid metal containers and cracked or chipped earthenware, which an acidic food can corrode or leach.
- Wear gloves when mixing the chili paste and keep hands away from your eyes.
- Kimchi is high in salt; count it on a low-sodium diet. Fish sauce adds a fish allergen.
- If you take an MAOI antidepressant, follow your prescriber's food list before eating home-fermented foods or fish sauce (tyramine).
Common questions
How long does kimchi need to ferment?
One to two days at a steady room temperature of about 68 degrees F, or three to four days in the refrigerator, according to Colorado State University Extension. It is ready to eat once a pH strip reads 4.6 or below.
How long does homemade kimchi last in the fridge?
Extension guidance ranges from about one week (Oregon State) to two weeks (Colorado State) for best quality. It keeps souring as it ages; discard it if surface mold appears.
How salty should kimchi be?
Oregon State University Extension gives a final salt concentration of 2 to 5 percent. In the Colorado State recipe the cabbage is salted for 3 to 6 hours, then rinsed 3 to 4 times, so a longer salting gives a saltier kimchi.
Sources
Primary research and government sources, each checked on the date this page was reviewed.
- GuidelineColorado State University Extension (Food Smart Colorado). Understanding and Making Kimchi. Updated 2025.
- GuidelineOregon State University Extension Service. Kimchi Basics (SP 50-1007).
- PubMedWastyk HC, et al. Gut-microbiota-targeted diets modulate human immune status. Cell. 2021. PMID 34256014.
- PubMedGillman PK. A reassessment of the safety profile of monoamine oxidase inhibitors: elucidating tired old tyramine myths. J Neural Transm. 2018. PMID 30255284.
Keep reading
- RemedyFermented foodsSauerkraut, kimchi, miso, kefir and kombucha. One well-run trial suggests eating more of them changes the gut microbiome; claims beyond that are mostly untested in people.
- Kitchen practiceFermentationThe oldest way to keep vegetables through winter. A tested method, the right salt and clean equipment make it safe; the health claims are more modest than the hype.
- ComparisonKimchi vs sauerkrautBoth are cabbage fermented by lactic acid bacteria. Kimchi has a handful of small trials on blood sugar and blood pressure; sauerkraut has a pilot study in IBS. Neither has enough to grade, so choose by taste, salt and how you will eat it.
- GoalFood and the gut microbiome: fiber, fermented foods and probioticsMicrobiome science is young. A varied, fiber-rich diet is sensible on many grounds, one small trial found fermented foods raised microbe diversity, and probiotic evidence is strain- and condition-specific.
- How to make itSauerkrautShredded cabbage, salt and time. The tested method from the National Center for Home Food Preservation, scaled to one 5-pound batch, with the safety checks that matter.