Recipes

Vegetables Drinks Dairy Koji Fruit and vinegar Sourdough Mead and cider
What can I ferment with what I have?
Recipes Learn Problems Tools Community

Language

Español Spanish English
My jars

The complete guide to kimchi

Kimchi ferments fast and is eaten when the pH says so. How to salt it, pack it and follow it until it's ready, with the figures from the guides.

9 min read Getting good Reviewed October 26, 2026 54 facts, each with its source

What kimchi is

Kimchi is vegetables fermented with a paste of chili, garlic and ginger. There are more than 200 kinds1; the best known, baechu kimchi, has napa cabbage, radish, green onion, garlic, ginger and a particular chili2: gochugaru, the Korean chili powder that gives it its heat and its red3. It needs no starter, because the bacteria that ferment it come on the ingredients4.

At heart it's like sauerkraut: vegetables, salt and lactic acid bacteria that sour them. But it goes much faster. It ferments in 1 or 2 days out of the fridge, or more slowly inside it5, which is why you follow it by pH rather than by the calendar.

Many traditional recipes use fish sauce, shrimp paste or salted anchovies6. Fervida's are vegetables only: not fermenting fish or seafood is a house rule.

Start with everything clean

Kimchi is eaten raw, with nothing to cook it. The outbreaks linked to kimchi come down to three things: poor-quality ingredients, poor hygiene and incomplete fermentation7. All three are in your hands.

  • Wash your hands with warm water and soap for at least 20 seconds8.
  • Wash the cabbage and the other vegetables under running water9.
  • Wash knives, boards, bowls and jars with soap, then dip them for at least 30 seconds in water at 160 °F (71 °C) or hotter10.

Salting: salt on everything

Cut the cabbage into pieces of about 2 inches (5 cm)11. Many Korean recipes soak it in a strong brine, 10 to 12%12, and then rinse it several times to wash the salt away13. That way nobody knows how much salt is left at the end, and the guides want that final salt between 2 and 5%14.

Fervida's recipes do it differently. You weigh all the cut vegetables and the chili, and the salt goes on the weight of everything: 2.5%, 25 g per kilo15, the final salt that a Korean study set when it standardized the proportions of napa cabbage kimchi16. Nothing is rinsed off, so that is the salt that stays. The minimum is 2%, because reducing salt is not safe17. Use coarse, non-iodized salt18.

Vegetables and chili Salt at 2.5%
600 g (1.3 lb) 15 g
1 kg (2.2 lb) 25 g
1.2 kg (2.6 lb) 30 g

Rub the salt into the vegetables and let them rest for 2 hours, massaging every 30 minutes19. The salt draws the water out, and that water is the ferment's brine20: don't pour it off.

The paste and the mix

Mince the garlic and ginger very fine, or blend them, and mix them with the gochugaru. Put on disposable gloves to work the paste into the vegetables and their liquid: they protect your hands from the chili21. Mix until everything is red.

Garlic is here as an aromatic, in small amounts. It is never the main vegetable of a ferment, because there are no validated recipes for fermenting it22.

Packing and closing

Pack the kimchi tightly into the jar, leaving no air pockets23. Pour the liquid from the bowl on top and press so it covers the vegetables. If it doesn't cover them completely at first, that's fine: the cabbage keeps releasing liquid little by little24. Fill the jar only two-thirds full: kimchi gives off gas, bubbles and rises25.

Use glass or food-grade plastic; no metal and no cracked earthenware26. Put the weight on top. A piece of plastic wrap on the surface helps keep mold off the top layer27.

You have two ways to close it:

  • Airlock lid: lets the gas out without letting air in28.
  • Regular lid, not tightened: just enough for the gas to escape29, but not so loose that insects and mold spores get in30.

Stand the jar on a plate in case it overflows31.

From the kitchen to the fridge

Leave the jar 1 or 2 days in the kitchen, at 20–22 °C (68–72 °F)32, loosely covered33. Check every day that the vegetables are still under the brine34. Bubbles usually show up in those days35: they're a good sign.

Then into the fridge. It's essential for flavor and for safety36, at 5 °C (41 °F) or below37. It goes in this early because in the first days the pH isn't yet low enough to hold back certain pathogens38. The cold holds them back while the flavor matures slowly39.

When Where What happens
Day 0 Kitchen, 20–22 °C (68–72 °F) You pack it and close it loosely
Days 1 and 2 Kitchen Bubbles appear
Day 2 Into the fridge, 5 °C (41 °F) or below It keeps fermenting slowly
Days 5 to 7 Fridge It tastes tangier40
Around 2 weeks Fridge The pH usually drops below 4.641

There's no fixed day, because the speed depends on the cold. The pH drops to 4.6 in about 2 days at 20 °C (68 °F), 6 at 10 °C (50 °F), 15 at 5 °C (41 °F) and 35 at 0 °C (32 °F)42. The longer it stays out and the warmer your fridge, the sooner it gets there.

When to eat it: the pH

Don't eat it until the pH is 4.6 or below43. Its optimum is a pH of 4.244. To measure it, a pH strip that reads from 3.0 to 5.5 is enough45, or a pH meter if you want more precision. Measure every few days from the first week on, and note what it reads.

Taste can't tell you: smell, texture and taste say a lot about quality, but they are not a reliable indicator of safety46. That's why the number rules.

Storing it, and when to throw it out

In the fridge, keep it pressed under its liquid so air doesn't reach it47. Over time it gets more sour48. That's not a flaw: in Korea, kimchi aged over six months, sourer and softer49, goes into soups and stews.

What is a problem: mold, an off smell that isn't the ferment's own, or an odd texture50. If you see any of the three, throw the kimchi out51. Mold is usually green, blue, brown or black52, and it can't be scooped out53. A good kimchi smells pleasantly sour, never putrid54.

The recipes, and your own

Fervida's five kimchi recipes follow this method, with the same salt and the same pH tracking:

  • Napa cabbage kimchi: the baechu, with radish, gochugaru, green onion, garlic and ginger.
  • White kimchi (baek kimchi): no chili, with daikon and pear. Mild and a little sweet.
  • Kkakdugi: cubed daikon. The radish releases so much liquid it covers itself.
  • Oi sobagi: cucumbers split crosswise and stuffed. The summer kimchi, and the first to soften.
  • Green onion kimchi (pa kimchi): whole green onions coated in red paste.

To make your own, use "What can I ferment with what I have?" and choose the kimchi method. You pick the main vegetable and the extras; the salt always comes out on the weight of everything, chili included. Extras weigh at most 30% of the main vegetable, which is a house rule.

Where every number comes from

Every number in the text leads to its figure: the exact sentence from the official guide it comes from, in its own language.

  1. 1

    There are more than 200 kinds of kimchi

    “There are more than 200 variations of kimchi; the types of ingredients and the preparation method have a profound impact on the taste.”

    Colorado State University Extension · Understanding and Making Kimchi (2025) · read on October 20, 2026

  2. 2

    Napa cabbage, radish, green onion, garlic, ginger and chili, in baechu style

    “Napa cabbage, radishes, green onions, garlic, and ginger, along with a specific red pepper, are used in classical baechu style”

    Colorado State University Extension · Understanding and Making Kimchi (2025) · read on October 20, 2026

  3. 3

    Gochugaru is Korean chili powder: it brings the heat and the red

    “Gochugaru is a type of Korean red chili pepper powder that gives kimchi its signature heat and vibrant red color.”

    University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026

  4. 4

    The bacteria come on the ingredients: no starter needed

    “The bacterial cultures needed for fermentation are present on the raw ingredients, so a ‘starter’ culture is unnecessary.”

    Oregon State University Extension Service · Preserving Foods: Kimchi Basics (SP 50-1007, March 2020) · read on October 20, 2026

  5. 5

    It ferments in 1 to 2 days at room temperature, or more slowly in the fridge

    “Kimchi ferments at room temperature in only 1-2 days or more slowly in the refrigerator.”

    Oregon State University Extension Service · Preserving Foods: Kimchi Basics (SP 50-1007, March 2020) · read on October 20, 2026

  6. 6

    Many recipes use fish sauce, shrimp paste or salted anchovies

    “fish sauce, shrimp paste, or salted anchovies are often used to enhance flavor”

    University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026

  7. 7

    Outbreaks come from poor ingredients, poor hygiene and incomplete fermentation

    “Large-scale outbreaks implicating kimchi occurred from poor quality of raw vegetable ingredients, unsanitary handling, and incomplete fermentation.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.3: Kimchi (2024) · read on October 26, 2026

  8. 8

    Wash your hands with soap for at least 20 seconds

    “Always start by washing your hands with soap and warm water for at least 20 seconds before handling any ingredients.”

    University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026

  9. 9

    Vegetables washed under running water

    “Wash the cabbage and other vegetables under running water to remove dirt and surface bacteria.”

    University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026

  10. 10

    Tools washed with soap and 30 seconds in water at 160 °F (71 °C) or hotter

    “wash it with soap and warm water, then submerge it in hot water that is at least 160 °F for at least 30 seconds.”

    University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026

  11. 11

    Pieces about 2 inches (5 cm)

    “Chop quarters into 2-inch pieces.”

    Colorado State University Extension · Understanding and Making Kimchi (2025) · read on October 20, 2026

  12. 12

    Many recipes salt in a 10 to 12% brine

    “A salt brine solution of 10-12% concentration is recommended.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.3: Kimchi (2024) · read on October 26, 2026

  13. 13

    And then rinse the salt off

    “Rinse cabbage pieces 3 to 4 times with cold water to rinse away the salt”

    Colorado State University Extension · Understanding and Making Kimchi (2025) · read on October 20, 2026

  14. 14

    Final salt ranges from 2 to 5%

    “the final salt concentration ranges from 2-5%.”

    Colorado State University Extension · Understanding and Making Kimchi (2025) · read on October 20, 2026

  15. 15

    25 g of salt per kilo

    “2.5% 25 g / kg food”

    UC Master Food Preservers, Inyo-Mono · Brine Math Made Easy · read on October 20, 2026

  16. 16

    A Korean study sets the final salt at 2.5%

    “and the final salt concentration 2.5 in the proportion of 100 salted chinese cabbage.”

    Korean Journal of Food Science and Technology (Cho, Park & Rhee), via KoreaScience (KISTI) · Standardization of Ingredient Ratios of Chinese Cabbage Kimchi (1997), abstract · read on October 20, 2026

  17. 17

    Reducing salt is not safe

    “It is unsafe to reduce salt in lactofermented vegetables.”

    UC Master Food Preservers, Inyo-Mono · Brine Math Made Easy · read on October 20, 2026

  18. 18

    Coarse non-iodized salt

    “coarse salt, non-iodized”

    Colorado State University Extension · Understanding and Making Kimchi (2025) · read on October 20, 2026

  19. 19

    Salt and rest 2 hours, massaging every 30 minutes

    “rub it with salt and allow it to rest, massaging it every 30 min for 2 hr.”

    University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026

  20. 20

    Salt draws water out of the cabbage and makes the brine

    “This process draws water out of the cabbage and creates the salty brine needed for fermentation.”

    University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026

  21. 21

    Disposable gloves to protect you from the chili

    “Disposable food handler gloves (highly recommended) for protection from red pepper powder”

    Colorado State University Extension · Understanding and Making Kimchi (2025) · read on October 20, 2026

  22. 22

    There are no validated recipes for fermenting garlic

    “There are currently no validated recipes for fermenting garlic.”

    Ask Extension (Loretta Sweeney, Franklin County, Ohio) · Food preservation and safety: lacto-fermenting garlic #930666 (2026) · read on October 25, 2026

  23. 23

    Packed tightly, without air pockets

    “the mixture is packed tightly into jars, minimizing air pockets.”

    University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026

  24. 24

    Press so the liquid covers the cabbage, which keeps releasing more

    “pressing down firmly to help liquid cover the cabbage. There may not be a lot of natural brine at this time, but the cabbage will continue to release it slowly.”

    Oregon State University Extension Service · Preserving Foods: Kimchi Basics (SP 50-1007, March 2020) · read on October 20, 2026

  25. 25

    Fill to two-thirds: it releases gas and bubbles

    “Fill container about 2/3 of the way full, as fermenting microorganisms will release carbon dioxide (CO2) and create bubbling and fizzing.”

    Colorado State University Extension · Understanding and Making Kimchi (2025) · read on October 20, 2026

  26. 26

    No metal, no cracked earthenware

    “Do not use metal containers nor earthenware with cracks or chips.”

    Colorado State University Extension · Understanding and Making Kimchi (2025) · read on October 20, 2026

  27. 27

    Plastic wrap on top keeps mold off the top layer

    “Plastic wrap may be placed over the kimchi to prevent mould forming on the top layer.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.3: Kimchi (2024) · read on October 26, 2026

  28. 28

    The valve lets the gas out

    “it is important to vent the jar with a one-way valve to release the gases that form during fermentation.”

    K-State Research and Extension (Kansas State University) · Taking a New Look at Fermented Foods (MF3491, June 2020) · read on October 20, 2026

  29. 29

    The lid not tightened, so the gas can escape

    “do not over tighten, to allow the carbon dioxide gases to escape.”

    Colorado State University Extension · Understanding and Making Kimchi (2025) · read on October 20, 2026

  30. 30

    But not so loose that insects and spores get in

    “lids should not be too loose to prevent contamination from insects & mold spores.”

    Colorado State University Extension · Understanding and Making Kimchi (2025) · read on October 20, 2026

  31. 31

    A plate underneath in case it overflows

    “Place on plate or in bowl to catch potential overflow.”

    Colorado State University Extension · Understanding and Making Kimchi (2025) · read on October 20, 2026

  32. 32

    Between 68 and 72 °F (20–22 °C)

    “Store in a cool (68°F-72°F”

    Oregon State University Extension Service · Preserving Foods: Kimchi Basics (SP 50-1007, March 2020) · read on October 20, 2026

  33. 33

    Loosely covered at room temperature for the first 48 hours

    “The jars should then be loosely covered and left at room temperature for the first 48 hr.”

    University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026

  34. 34

    Check daily that it stays submerged

    “Check daily to make sure vegetables remain submerged in brine.”

    Oregon State University Extension Service · Preserving Foods: Kimchi Basics (SP 50-1007, March 2020) · read on October 20, 2026

  35. 35

    Bubbles show up in the first 1 to 2 days

    “typically within the first 1 to 2 days at room temperature, visible bubbling may occur”

    University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026

  36. 36

    Moving it to the fridge is essential for flavor and safety

    “it is essential to transfer kimchi to the refrigerator to ensure both flavor development and safety.”

    University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026

  37. 37

    In the fridge at 41 °F (5 °C) or below

    “Maintaining a storage temperature of 41 °F or below helps ensure both the safety and quality of the final product”

    University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026

  38. 38

    In the first days the pH isn't low enough yet

    “During the early stages of fermentation, the pH may not yet be low (acidic) enough to prevent the proliferation of certain pathogens.”

    University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026

  39. 39

    Cold holds back harmful microbes while the flavor matures

    “Refrigeration slows down the fermentation process, allowing flavors to mature gradually while also suppressing the growth of harmful microorganisms.”

    University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026

  40. 40

    By day 5 to 7 it tastes tangier

    “By days 5 to 7, the kimchi develops a tangier flavor”

    University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026

  41. 41

    At about 2 weeks the pH drops below 4.6

    “After approximately 2 weeks, the fermentation process leads to a sufficiently acidic environment”

    University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026

  42. 42

    pH reaches 4.6 in 2 days at 68 °F, 6 at 50 °F, 15 at 41 °F and 35 at 32 °F

    “During kimchi fermentation, pH drops to approximately 4.6 or lower in 2 days at 20oC, 6 days at 10oC, 15 days at 5oC and 35 days at 0oC.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.3: Kimchi (2024) · read on October 26, 2026

  43. 43

    It isn't eaten until the pH is 4.6 or below

    “For safety, kimchi should reach a pH of 4.6 or below before consuming.”

    Colorado State University Extension · Understanding and Making Kimchi (2025) · read on October 20, 2026

  44. 44

    Kimchi's optimum pH is 4.2

    “results in an optimum kimchi pH of 4.2.”

    Colorado State University Extension · Understanding and Making Kimchi (2025) · read on October 20, 2026

  45. 45

    pH strips that read from 3.0 to 5.5

    “To verify pH, use a pH test strip that can test a range of 3.0-5.5 pH.”

    Colorado State University Extension · Understanding and Making Kimchi (2025) · read on October 20, 2026

  46. 46

    Smell, texture and taste are not a reliable indicator of safety

    “Sensory analysis, referring to the evaluation of smell, texture and taste of a food, may also be recommended when assessing quality of the food, but is not a reliable indicator of food safety.”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 2: Starter cultures and fermented food standards (August 2024, updated December 2024) · read on October 25, 2026

  47. 47

    Keep it pressed down so air doesn't reach it

    “Keep it pressed down to minimize air exposure.”

    Colorado State University Extension · Understanding and Making Kimchi (2025) · read on October 20, 2026

  48. 48

    Over time it gets more sour

    “Kimchi may become more sour over time.”

    Colorado State University Extension · Understanding and Making Kimchi (2025) · read on October 20, 2026

  49. 49

    Kimchi over six months old, sourer and softer, goes into soups and stews

    “Prolonged fermentation over six months produces higher acidity and a softer texture in this kimchi. It is used as an ingredient for kimchi soup or other Korean cuisines”

    BC Centre for Disease Control, Environmental Health Services · Safety of Fermented Foods, Section 3.3: Kimchi (2024) · read on October 26, 2026

  50. 50

    Mold, an off smell or an odd texture are signs of spoilage

    “Signs of spoilage include the presence of mold, an off-putting odor distinct from its characteristic fermented aroma, or an unusual texture.”

    University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026

  51. 51

    If you see them, throw the kimchi out

    “If any of these signs are observed, discard the kimchi to prevent potential foodborne illness.”

    University of Georgia Cooperative Extension · Homemade Kimchi: A Science-Based Guide to Safe Fermentation (Circular 1362, 2025) · read on October 20, 2026

  52. 52

    Mold is usually green, blue, brown or black

    “Mold is typically green, blue, brown, or black in color.”

    UC Davis, Department of Food Science and Technology · Common issues with fermented fruits and vegetables (v1.0, 15-mar-2022) · read on October 20, 2026

  53. 53

    Mold can't be scooped out

    “The mold cannot be scooped out, as the roots will still be in your food and could make you sick.”

    Ask Extension (Clackamas County Extension, Oregon State University) · Pickle/olive brine surface mold spots #889210 · read on October 20, 2026

  54. 54

    It smells pleasantly sour, not putrid

    “A fermented fruit or vegetable will smell pleasantly sour but not putrid.”

    UC Davis, Department of Food Science and Technology · Common issues with fermented fruits and vegetables (v1.0, 15-mar-2022) · read on October 20, 2026

Keep reading

Salt: how much and why pH and why it matters most pH meters and strips Jars and lids Temperature and time Fermenting safely: botulism and how to avoid it The complete guide to sauerkraut Cooking with ferments