What Is Doenjang? Korea's Fermented Soybean Paste

If miso is the fermented soybean paste most of us met first, doenjang is its bolder, older-tasting cousin from Korea. It is made from just three ingredients, aged for months, and it anchors some of the most comforting dishes in Korean cooking. Here is what it is, how it is made, and what researchers have actually studied.

Last reviewed: October 2026 by the Haelan Publishing Team

What is doenjang?

Doenjang (pronounced roughly "dwen-jahng") is a thick, brown Korean paste made by fermenting soybeans with salt and water over several months. The name means "thick paste," and it belongs to a family of Korean fermented soy seasonings called jang, alongside ganjang (soy sauce) and gochujang (red pepper paste) [1].

The flavor is where doenjang announces itself. It is salty, earthy and intensely savory, with a pungent edge that mellows into something rounded and almost nutty once it hits hot broth. If you have read our beginner's guide to miso, tempeh, natto and other fermented soy foods, think of doenjang as sitting at the stronger, funkier end of that family. Its best-known home is doenjang-jjigae, a bubbling stew of tofu, zucchini and the paste itself, and ssamjang, the dipping sauce served with lettuce wraps.

How is doenjang made?

Doenjang is made in two stages: soybeans are first fermented into dried blocks called meju, and the meju is then aged in salt brine until it becomes paste. I like to think of meju as a sourdough starter you can stack: a brick of cooked soybeans that collects its own community of microbes from the air, the straw it hangs on and the room it dries in.

The traditional process, as described in a 2022 review in Fermentation and a 2014 study in the Journal of Microbiology and Biotechnology, looks like this [1] [2]:

1. Soak and cook. Dried soybeans are soaked, then steamed or boiled until soft.
2. Mash and mold. The cooked beans are crushed and pressed into blocks. These blocks are meju.
3. Dry and ferment. The meju is dried and left to ferment naturally. Bacteria such as Bacillus subtilis (the same species family behind natto) and molds such as Aspergillus oryzae (the mold used to make koji for miso and sake) grow through the block and begin breaking down its proteins.
4. Brine. The meju is submerged in a strong salt brine, about 18% salt in the 2014 study, and ripened for roughly 30 to 180 days. The 2022 review describes traditional brining of at least six months.
5. Separate. The liquid is drawn off and becomes ganjang, Korean soy sauce. The solids are mashed and become doenjang.
6. Age. The paste continues to ripen in earthenware crocks, growing darker and deeper in flavor.

What happens to the microbes along the way is interesting. In that 2014 study, lactic acid bacteria that dominated early meju could not survive the brine, while salt-tolerant Bacillus species persisted throughout ripening and new salt-loving bacteria appeared, probably arriving with the sea salt itself [2]. Many modern factory versions skip the wild stage and use selected starter cultures under controlled conditions instead [1].

Doenjang vs miso: what's the difference?

The main difference between doenjang and miso is the starter: doenjang begins with whole-soybean meju blocks fermented largely by Bacillus bacteria, while miso begins with koji, a grain such as rice or barley grown with Aspergillus oryzae mold. That one choice ripples through flavor, texture and ingredients. We cover the Japanese side in more detail in our comparison of white miso and red miso.

	Doenjang	Miso
Origin	Korea	Japan
Starter	Meju: dried blocks of cooked soybeans, traditionally fermented by naturally occurring microbes	Koji: rice, barley or soybeans deliberately grown with Aspergillus oryzae
Lead microbes	Bacillus species, plus molds and salt-tolerant bacteria	Aspergillus oryzae, followed by yeasts and lactic acid bacteria
Traditional ingredients	Soybeans, salt, water	Soybeans, grain koji, salt
Flavor	Pungent, earthy, sharply savory	Milder and often sweeter, especially white miso
Texture	Coarse, often with visible bean pieces	Usually smoother
In the kitchen	Simmered in stews; holds its flavor through long cooking	Often stirred in at the end of cooking

Can you swap one for the other? In a pinch, yes, but expect a different dish. Doenjang is more assertive, so cooks who substitute it for miso generally start with less and taste as they go.

Is doenjang good for you?

Doenjang is a nutrient-dense traditional food whose long fermentation changes soy's compounds in ways researchers find interesting, but human studies on doenjang itself are few, small and not yet conclusive. Here is what the better evidence says, and where it stops.

Fermentation changes the isoflavones. Isoflavones are plant compounds found naturally in soybeans. In the raw bean most are glucosides, meaning they are attached to a sugar molecule. Fermentation or digestion removes that sugar and leaves the aglycone, the "free" form, according to the Linus Pauling Institute [6]. A 2024 study in Food Science and Technology Research measured three commercial Korean products and found that the long-fermented doenjang had converted 81.5% of its isoflavone glucosides to aglycones, compared with 8.9% and 33.7% in two short-fermented cheonggukjang samples [3]. That is only three products, so it is a snapshot, not a rule. We explain why the form matters in our piece on fermented versus unfermented soy.

Population data are mixed and observational. A 2020 cross-sectional analysis in Nutrients of 11,566 Korean adults aged 50 and older (KNHANES 2013 to 2018) found that postmenopausal women with the highest fermented soy intake had lower odds of hypertension than those with the lowest (odds ratio 0.81), while no association appeared in men [5]. The survey counted doenjang together with three other fermented soy products, relied on a single 24-hour diet recall, and by design cannot show cause and effect.

Human trials exist but are small. The 2022 Fermentation review summarizes a 12-week trial in which adults eating 9.8 g of doenjang a day showed a reduction in visceral fat area of 8.6 cm², and notes that responses appeared to differ by gene variant [1]. A separate 2021 review in Annals of Microbiology points out that most findings on doenjang's Bacillus microbes come from cell and animal work, and that confirmation in human volunteers is still to come [8].

The honest limits. Observational studies show associations, not cause and effect. The trials are short and small, the products tested vary enormously from one maker to the next, and results from rats or cell dishes do not automatically apply to people. Nothing here shows that doenjang, or any fermented soy food, changes the course of any medical condition.

A quick, friendly note: this article is for educational purposes only. Everyone's body and circumstances are different, so please talk with your healthcare professional before making meaningful changes to how you eat.

How much salt is in doenjang, and who should ask a clinician first?

Doenjang is a high-salt food: a 2023 analysis in Foods of 36 traditionally made Korean doenjang products measured salinity between 10.83% and 16.79% [4]. Salt is what keeps the paste safe through months of aging, and it is also why doenjang is used as a seasoning, a spoonful dissolved into a whole pot, not eaten by the bowl.

The same study measured biogenic amines, compounds that form naturally in aged and fermented foods. Tyramine ranged from 3.23 to 101.23 mg/kg and histamine from 0.97 to 1,289 mg/kg across the 36 samples, a very wide spread, and the authors called for regular monitoring and larger studies [4]. For most people this is simply background detail. For a few groups it is worth a conversation first:

If this applies to you	Why to check with your clinician
You take an MAO inhibitor	Mayo Clinic lists fermented soybean paste, miso and soy sauce among the tyramine-containing foods people on these medicines are told to avoid [7]
You follow a sodium-restricted eating plan	Measured salinity of roughly 11% to 17% in traditional products [4]
You take thyroid medication	Soy protein taken at the same time as levothyroxine has been reported to raise the dose needed [6]; see our article on soy and thyroid function
You take tamoxifen or have a hormone-sensitive condition	The Linus Pauling Institute advises seeking medical advice before using soy protein supplements or isoflavone extracts [6]; ask how that applies to soy foods for you
You take warfarin	A case report describes changed INR values in one person drinking soy milk daily [6]; your prescriber can advise on keeping intake consistent
You have a soy allergy	Doenjang is made from soybeans [1]
You are pregnant	We found no doenjang-specific research in pregnancy among the sources reviewed here; your prenatal clinician is the right guide

Common questions

What does doenjang taste like?
Doenjang tastes salty, earthy and deeply savory, with a pungent aroma that softens when it is cooked into broth. It is generally stronger and less sweet than Japanese miso, and its texture is coarser, often with visible pieces of soybean. Most people meet it first in doenjang-jjigae, a Korean stew, where the sharpness rounds out into a rich, comforting depth.

Is doenjang the same as miso?
No. Both are fermented soybean pastes, but doenjang starts from meju, blocks of cooked soybeans fermented largely by Bacillus bacteria, while miso starts from koji, a grain grown with Aspergillus oryzae mold. Traditional doenjang contains only soybeans, salt and water, and typically tastes stronger and earthier than miso [1].

Does doenjang have probiotics?
Traditional doenjang contains live microbes, mainly salt-tolerant Bacillus species that persist through ripening [2]. Whether those microbes act as probiotics in people has not been established in human trials [8], and doenjang is usually simmered. Our guide to what cooking does to the microbes in fermented foods explains what heat changes and what it leaves behind.

Is doenjang gluten-free?
Traditional doenjang is made from only soybeans, salt and water, so it contains no wheat. Some recipes and commercial products, however, add barley, rice or wheat during fermentation or blending [1]. If you avoid gluten, read the ingredient list on the specific tub and look for a certified gluten-free statement instead of assuming.

How do you store doenjang, and does it go bad?
Doenjang is a high-salt, long-aged food, which makes it very stable. Most makers recommend keeping an opened tub tightly sealed in the refrigerator. It commonly darkens over time as it continues to age; that is normal. Follow the storage directions and date on your product's label, and discard it if you see fuzzy mold or notice an off smell.

The bottom line

Doenjang is one of the great slow foods: three ingredients, a brick of beans, a crock of brine and a lot of patience. Fermentation transforms the soybean's proteins and isoflavones along the way, and researchers are studying what that might mean, but the human evidence is still early and the paste is undeniably salty. Enjoy it for what it certainly is, a deeply flavorful way to bring a traditional fermented soy food to your table. If you are curious how whole fermented soy compares with pills and extracts, our look at isoflavone supplements versus whole soy foods is a good next read.

Doenjang is one expression of fermented soy; Haelan 951 is a very different one. It is a concentrated organic, non-GMO fermented soy beverage made with a proprietary nitrogen fermentation process, and the FDA classifies it as a food, not a supplement or a drug. It contains naturally occurring soy compounds such as isoflavones, saponins and phytosterols. It is not doenjang and is not made with meju or brine. For serving size and how to use it, please follow the product label.

Discover Haelan 951 →

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References: [1] Jung S-J, Chae S-W, Shin D-H. Fermented Foods of Korea and Their Functionalities. Fermentation. 2022;8(11):645  [2] Jeong et al. Bacterial Community Migration in the Ripening of Doenjang, a Traditional Korean Fermented Soybean Food. Journal of Microbiology and Biotechnology. 2014  [3] Inagaki S, Fujimoto H. Isoflavone aglycone contents of commercial fermented soybean products in Korea and the isoflavone aglycone-producing ability of Bacillus subtilis isolated from the products. Food Science and Technology Research. 2024;30(2)  [4] Bahuguna A, Kumar V, Bodkhe G, et al. Safety Analysis of Korean Cottage Industries' Doenjang, a Traditional Fermented Soybean Product: A Special Reference to Biogenic Amines. Foods. 2023  [5] Yoo D, Park Y. Association between the Intake of Fermented Soy Products and Hypertension Risk in Postmenopausal Women and Men Aged 50 Years or Older: The Korea National Health and Nutrition Examination Survey 2013–2018. Nutrients. 2020  [6] Linus Pauling Institute, Oregon State University. Soy Isoflavones. Micronutrient Information Center  [7] Mayo Clinic. MAOIs and diet: Is it necessary to restrict tyramine?  [8] Gopikrishna et al. Impact of Bacillus in fermented soybean foods on human health. Annals of Microbiology. 2021

This content is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Always consult your healthcare professional before making changes to your diet or health routine.