The Soul of Korean Cuisine: Soy Sauce and Doenjang, the Taste of Time
In every Korean kitchen, there are two ingredients that define the very essence of flavor — soy sauce (ganjang, 간장) and soybean paste (doenjang, 된장).
They are more than just condiments; they are the foundation of Korean seasoning, the silent storytellers of time, care, and tradition.
Together, these two fermented treasures represent the depth of Korean flavor — known as “jang” (장), which refers collectively to traditional fermented sauces such as soy sauce, soybean paste, and red chili paste (gochujang).
The Beginning of All Jang: Meju (메주)
The heart of both soy sauce and doenjang lies in a humble, hand-formed block of soybeans called meju (메주).
To make meju, soybeans are soaked, boiled, and mashed, then shaped into rectangular blocks and tied with rice straw.
These blocks are hung in warm, airy places — traditionally under the eaves of homes — to ferment naturally for weeks.
During this time, something magical happens:
naturally occurring molds and bacteria from the rice straw and air begin to grow on the surface of the meju.
Far from being harmful, these microorganisms are the key to creating deep umami flavor and rich aroma.
This beneficial mold, similar to what’s used in cheese or miso fermentation, helps break down the soybean proteins into amino acids — the building blocks of savory taste.
It’s a slow, living process guided by nature and time rather than precision or control.
From Meju to Ganjang and Doenjang
Once the meju blocks are fully dried and fermented, the next step begins — the birth of Korean sauces.
The blocks are placed in large earthenware jars called onggi (옹기) and submerged in a brine solution of sea salt and water.
Then, the jars are left to ferment for several months, often from winter through spring, in a sunny outdoor area known as the jangdokdae (장독대) — a sacred space where the family’s sauces matured under the sky.
Over time, the liquid portion becomes soy sauce (ganjang), while the solid portion becomes soybean paste (doenjang).
The process is called “doenjang gareugi” (된장 가르기) — literally “separating the doenjang.”
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The upper liquid layer is drawn off and aged further to create soy sauce, used in seasoning, braising, and dipping sauces.
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The remaining solids are mashed and aged again in the jar, deepening in flavor and transforming into doenjang — a rich, earthy paste used for soups and stews.
Nothing goes to waste, and both condiments carry the essence of the same meju — one becoming liquid umami, the other a savory, grounding paste.
How to Make Traditional Ganjang and Doenjang at Home
While the full process of making Korean soy sauce and soybean paste traditionally can take months, it follows a simple but sacred rhythm passed down for generations.
Here’s a step-by-step look at how it’s done in Korean homes — from meju to finished jang.
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Prepare the Meju Blocks:
Start with soybeans that are soaked overnight and boiled until soft.
Mash them thoroughly, then shape them into square or rectangular blocks.
Tie the blocks with rice straw and hang them in a warm, dry place for two to four weeks to ferment naturally.
White and gray molds will appear — these are beneficial molds that create the deep savory flavors of jang. -
Soak and Salt:
Once the meju blocks are fully dried and firm, place them in large earthenware jars (onggi) and pour over a brine made of coarse sea salt and clean water.
Use a ratio of about 1 part salt to 10 parts water, ensuring the blocks are completely submerged.
Cover the jars with breathable cotton cloths and set them in a sunny, well-ventilated area. -
Ferment with Sun and Wind:
Allow the jars to ferment naturally for 40 to 60 days, depending on the temperature.
During this time, the sun, air, and beneficial bacteria will separate the mixture into liquid and solid components.
Skim off any white film that forms on the surface — this is a normal part of the process. -
Separate the Jang (Doenjang Gareugi):
After fermentation, gently strain the liquid and solid parts.
The liquid becomes soy sauce (ganjang) — it can be boiled once, cooled, and aged further for a deeper flavor.
The solids are mashed, placed back into a clean jar, and left to age again for another few months to develop into doenjang. -
Aging and Finishing:
Traditionally, soy sauce is aged for 6 months to a year, while doenjang continues to mature for up to a year or more.
The longer it ferments, the richer and more complex the flavor becomes.
During the aging process, keep the jars clean, occasionally remove surface molds, and allow sunlight to help the fermentation breathe. -
The Blessing of the Jangdokdae:
In the past, families would visit the jangdokdae on the first sunny day of spring, uncover the lids, and let the jars “breathe.”
This day was called “Jang Punggi” (장풍기) — the day to give the jang a taste of spring air.
It was also a time when mothers would pray for their family’s health and happiness, believing that good jang brought harmony to the home.
The Sacred Tradition of Jangdokdae
In the past, making jang wasn’t just cooking — it was a spiritual ritual.
Families treated their fermentation jars as sacred vessels, believing that the health of the household depended on the well-being of their jang.
It was common to see a clean bowl of water placed on the jangdokdae, the stone platform where the jars rested.
Mothers would look up at the sky, offer a quiet prayer for their family’s health, happiness, and good harvest, and trust that the sun, wind, and time would do their part.
During the fermentation season, people sometimes tied “geumjul” (금줄) — a straw rope with paper streamers — around the jars to ward off bad luck or evil spirits.
It was a symbolic act of protection, ensuring the jang would ferment peacefully without contamination.
Though these customs have mostly disappeared today, the reverence remains — a cultural memory of how deeply Koreans valued food, nature, and the unseen forces that sustain life.
The Science and Art of Fermentation
Behind the poetic tradition lies fascinating food science.
The microbes in meju — mainly Aspergillus oryzae and Bacillus subtilis — break down the soy proteins and starches during fermentation.
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For soy sauce, enzymes convert amino acids and sugars into complex savory, slightly sweet, and aromatic flavors.
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For doenjang, the breakdown continues, resulting in dense umami depth, earthy aroma, and natural saltiness.
The clay jars (onggi) themselves play an essential role — they “breathe,” allowing air to circulate while releasing moisture.
This balance of airflow and humidity is what makes traditional Korean fermentation unique and impossible to replicate in metal or plastic containers.
Modern Times, Ancient Flavors
Today, most households buy commercially made soy sauce and doenjang, but many families and artisans still make traditional jang every winter.
It’s a way to stay connected to their roots — to remember the taste of their grandmother’s doenjang stew or the soy sauce that flavored every childhood meal.
Even modern chefs and home cooks return to handmade jang for its complexity — rich, natural, and alive.
The time, patience, and microbes combine to create something no machine can replicate: flavor born from nature and care.
How Koreans Use Soy Sauce and Doenjang
These two condiments form the backbone of Korean flavor:
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Soy Sauce (Ganjang): Used for seasoning soups, stir-fries, and marinades. It adds salinity and umami depth.
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Jangjorim: Braised beef in soy sauce.
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Gyeran-jangjorim: Soy-braised eggs.
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Japchae: Glass noodles stir-fried with soy sauce and sesame oil.
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Doenjang (Soybean Paste): Used as a main flavor base for stews and dips.
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Doenjang Jjigae: Hearty soybean paste stew with tofu and vegetables.
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Ssamjang: A spicy-salty dip made with doenjang, gochujang, and sesame oil — essential for Korean BBQ.
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Each carries the flavor of home — one liquid, one solid — both infused with the same history and heart.
More Than Seasoning: A Taste of Korean Spirit
Soy sauce and doenjang represent more than flavor; they embody Korean patience, respect for nature, and family bonds.
They are foods that mature slowly — just as relationships and wisdom do.
Every drop of ganjang and every spoon of doenjang is a reminder that good things take time — and that food, when made with care and gratitude, becomes something sacred.
Even though modern convenience has replaced many traditional practices, the memory of mothers standing before the jangdokdae, offering wishes for their families, still lingers in the taste of every Korean meal.
That is the true essence of Korean jang — the taste of time, tradition, and love.
