Soybean paste is a thick, salty condiment made from fermented soybeans. Found across East and Southeast Asian cuisines, it serves as a foundational source of umami, the deep savory flavor that anchors soups, stews, marinades, and sauces. At its simplest, soybean paste requires just three things: soybeans, salt, and time. Microorganisms break the beans down over weeks or months, transforming a bland legume into one of the most flavor-dense ingredients in any kitchen.
How Soybean Paste Is Made
The basic process has remained largely the same for centuries. Soybeans are cleaned, soaked, and then steamed or boiled until soft. The cooked beans are mashed or shaped into blocks, then inoculated with naturally occurring molds, bacteria, or both. These microorganisms begin breaking down the proteins and starches in the beans, a process that generates the paste’s characteristic deep, complex flavor.
Once the initial fermentation is underway, salt enters the picture. The fermented soybean blocks are typically soaked in a brine solution of around 18 to 20 percent salt for at least 30 days. The salt controls the fermentation, preventing harmful bacteria from growing while allowing beneficial microbes to do their work. After the brine soak, the solids are separated, and the paste enters a longer aging phase at warm temperatures (around 36°C or 97°F) that can last two months or more. From start to finish, a traditionally made soybean paste takes roughly four months to produce, though some varieties age for a year or longer.
During fermentation, enzymes release minerals like phosphorus, calcium, and iron from the soybeans, making them easier for your body to absorb. Microbial activity also generates B vitamins that aren’t present in the raw beans. The result is a product that’s nutritionally richer and more digestible than the soybeans it started as.
Major Regional Varieties
Soybean paste isn’t one product. It’s a family of condiments that varies significantly from country to country.
Korean Doenjang
Doenjang is the most traditional and arguably the most intense version. It’s made by fermenting blocks of soybeans called meju, then separating them from the brine (which becomes Korean soy sauce). The remaining solids are packed and aged further. Doenjang has a strong, pungent flavor with a rough, chunky texture. An even more assertive relative, cheonggukjang, ferments for a much shorter time but develops an intensely funky aroma sometimes compared to blue cheese.
Japanese Miso
Miso uses a similar principle but introduces a key variable: a grain-based starter culture, often grown on rice or barley. Adjusting the ratio of soybeans to grain and the length of fermentation produces a wide spectrum of flavors. White miso ferments for a shorter period and tastes mild and slightly sweet. Red miso ages longer and develops a deeper, saltier profile. Compared to doenjang, miso tends to be smoother in texture and more subtle in flavor.
Chinese Doubanjiang and Tianmianjiang
China produces several soybean pastes. Doubanjiang, a staple of Sichuan cooking, blends fermented soybeans with chili peppers and broad beans, creating a spicy, savory base for stir-fries and braises. Tianmianjiang (sweet bean paste) is fermented with wheat flour, giving it a sweeter, thicker quality used in dishes like Peking duck wraps and zhajiangmian noodles.
Southeast Asian Tauco
In Indonesia and Malaysia, tauco (or tauchu) is a looser, more liquid soybean paste often containing whole or partially broken beans. It appears in stir-fries, soups, and braised dishes throughout the region.
Nutrition at a Glance
Soybean paste packs a surprising nutritional punch for a condiment. Per 100 grams, a typical fermented soybean paste contains roughly 12 grams of protein and 5.4 grams of dietary fiber. It’s also a meaningful source of isoflavones, plant compounds with antioxidant properties found naturally in soybeans. Fermentation concentrates these compounds and may make them more bioavailable.
The trade-off is sodium. That same 100-gram serving contains about 3,728 milligrams of sodium, nearly double the World Health Organization’s recommended daily limit of 2,000 milligrams. In practice, most people use soybean paste a tablespoon or two at a time, not by the hundred grams. But if you’re watching your salt intake, it’s worth measuring rather than eyeballing.
Health Benefits of Fermented Soy
The isoflavones in soybean paste act as both antioxidants and mild phytoestrogens, plant compounds that can interact with estrogen receptors in the body. Research links these compounds to a range of potential benefits: supporting cardiovascular health, improving cholesterol profiles, helping maintain bone density, and easing menopausal symptoms like hot flashes. One randomized controlled trial found that men with moderately high cholesterol who supplemented with fermented soy products saw improvements in their lipid profiles.
The antioxidant activity of isoflavones may also play a protective role in brain health. Some research suggests they can inhibit changes to proteins associated with Alzheimer’s disease. Isoflavones have additionally shown the ability to reduce allergic responses by limiting the activity of immune cells involved in allergic reactions.
Longer fermentation appears to amplify some of these benefits. Studies on doenjang have found that extended aging increases both the amino acid content and certain anticancer properties of the paste. This aligns with a general pattern in fermented foods: more time typically means more bioactive compounds.
The Sodium Question
Given that soybean paste can be 12 percent salt or higher by weight, it’s reasonable to wonder whether regular consumption raises blood pressure. The answer is more nuanced than you might expect. A study examining the effects of doenjang on blood pressure in rats found that consuming traditional soybean paste, even at high-salt concentrations, did not directly cause hypertension. Researchers have speculated that other compounds produced during fermentation, including peptides and amino acids, may partially counteract sodium’s effects on blood vessels.
That said, soybean paste remains one of the top contributors to dietary sodium in countries where it’s consumed daily, alongside soy sauce and kimchi. Using reduced-salt versions (some commercial products bring salt content down to 8 percent) or simply being mindful of portion sizes are practical ways to enjoy it without overdoing sodium.
How It’s Used in Cooking
Soybean paste rarely plays a solo role. It works as a background flavor engine, adding depth and savoriness to dishes that would otherwise taste flat. In Korean cooking, doenjang jjigae (soybean paste stew) is the quintessential example: tofu, zucchini, onions, and chili simmered in a doenjang-laced broth. It’s a dish built almost entirely on the paste’s umami. Doenjang also forms the base of ssamjang, a thick dipping sauce mixed with chili paste and sesame oil, served alongside grilled meats and lettuce wraps.
Lighter applications work just as well. Miso dissolves easily into soups and salad dressings. Whisked into a marinade, it tenderizes proteins while adding a salty, fermented complexity. Doenjang guk, a simple Korean soup, combines the paste with vegetables like cabbage or radish in a light broth for an everyday side dish. Gamjatang, a hearty pork bone and potato stew, uses soybean paste alongside chili flakes for a rich, layered spiciness.
One practical tip: heat affects soybean paste differently depending on the variety. Miso loses some of its more delicate flavors when boiled for a long time, which is why it’s typically stirred into soup at the very end. Doenjang, on the other hand, stands up well to prolonged cooking and actually deepens in flavor the longer it simmers.
Choosing and Storing Soybean Paste
At an Asian grocery store, you’ll find soybean paste in tubs, jars, and pouches. For a first purchase, a medium-colored miso (often labeled “yellow” or “awase”) offers the most versatility. If you want the full-bodied, pungent flavor common in Korean soups and stews, doenjang is the better choice. Check the ingredient list: the best products contain little more than soybeans, salt, and water. Some commercial versions add sugar, MSG, or preservatives, which isn’t necessarily harmful but does change the flavor profile.
Soybean paste keeps well. Stored in the refrigerator with the lid tightly sealed, most varieties last six months to a year. The surface may darken over time as oxidation occurs, but this doesn’t mean it’s gone bad. Simply stir the paste before using it. The high salt content acts as a natural preservative, which is the whole reason salt was added in the first place hundreds of years ago.