The Ancient Mycoprotein Tradition: Fermented Fungal Foods as Precursor

What it is

The ancient fermented fungal food tradition is one of the most sophisticated and nutritionally complete protein systems humans ever developed — created not through industrial design but through millennia of empirical observation, cultural transmission, and culinary refinement. Tempeh, miso, doenjang, cheonggukjang, natto, oncom, meju — these are, at their biological core, foods in which edible fungi and bacteria are used to transform plant proteins into more digestible, nutritionally dense, and shelf-stable forms. When a Javanese cook presses cooked soybeans into a tempeh mold inoculated with Rhizopus oligosporus, she is producing mycoprotein in exactly the technical sense the term implies: protein synthesized and bound within a fungal mycelium matrix.

The significance of recognizing this continuity is not merely historical. It means that the modern mycoprotein industry did not invent a new food category. It industrialized one that had existed for at least a thousand years, primarily in Asia, and that billions of people had already found safe, nutritious, delicious, and culturally central.

History & domestication

Tempeh is the most structurally analogous of the ancient fermented fungal foods to modern mycoprotein. Its origins are in Java, with the earliest written records appearing in the Serat Centhini, a Javanese encyclopedic text compiled in the early 19th century, though the practice is certainly older. Tempeh production relies on Rhizopus oligosporus, a mold that grows through cooked soybeans, binding them into a firm white cake with its dense mycelial network. The mold is the protein — or more precisely, the mold multiplies the protein, because its mycelium adds substantial protein mass to the substrate while also producing enzymes that pre-digest the soybean proteins into more bioavailable forms.

Koji fermentation, the cornerstone of Japanese, Korean, and Chinese preserved food traditions, relies on Aspergillus oryzae grown on grains or legumes. The Aspergillus mold produces a remarkable enzyme cascade — amylases, proteases, lipases — that breaks down starches into sugars and proteins into amino acids, creating the savory depth of flavor that characterizes miso, sake, soy sauce, and dozens of other fermented condiments. The mold is not eaten directly in most of these applications (it is washed or cooked away), but it transforms the protein substrate profoundly.

Oncom, a fermented peanut or soy byproduct food traditional to West Java and Sundanese cuisine, takes two forms: red oncom, made with Neurospora sitophila, and black oncom, made with Rhizopus oligosporus. Both involve fungal mycelium growing through agricultural waste products — peanut press cake, soy pulp (okara), coconut press cake — and transforming them into a firm, nutritious, edible cake. Oncom is the world's most efficient use of agricultural byproducts as mycoprotein: it takes what would otherwise be discarded and makes it into a nutritionally complete food through fungal action.

Cultural significance

In Java, tempeh is not a health food or a meat substitute. It is a staple — eaten daily, fried, steamed, grilled, simmered in coconut milk, fermented further into the pungent aged tempeh that some connoisseurs prefer. It crosses class lines in a way that few Indonesian foods do. A street vendor frying tempeh mendoan in a wok of hot oil and a restaurant serving tempeh bacem in a refined sauce are both feeding the same cultural tradition. The fact that tempeh has been adopted in the West primarily as a vegetarian meat substitute would be bewildering to most Javanese, for whom it has never been an alternative to anything — it is simply food.

Natto, the intensely fermented soybean product of Japan produced by Bacillus subtilis rather than a mold, occupies a similarly central but contested cultural position. The sticky, stringy texture and pungent ammonia-adjacent aroma that make natto beloved in the Kanto region of Japan make it nearly inedible to most people encountering it for the first time. Natto is, in Japanese food culture, a shibboleth — a food that marks belonging. Eating it enthusiastically signals cultural fluency. The specific nutritional contribution of natto — it is exceptionally high in Vitamin K2, nattokinase enzyme, and complete protein — has made it a subject of intense interest in the functional food industry, though the cultural dimensions of natto resist easy commercialization.

Religious & theological context

The fermented fungal food tradition has navigated religious dietary frameworks with remarkable flexibility. Tempeh and miso are generally accepted as permissible under Islamic dietary law, though questions arise around fermentation-produced alcohol: the trace amounts of ethanol produced during tempeh and koji fermentation are considered negligible and do not render the product haram under mainstream Islamic jurisprudence. Under Jewish dietary law, fermented soy products like miso and tempeh are pareve (neither meat nor dairy) and can be eaten freely, though specific products require kosher certification to ensure no cross-contamination with non-kosher ingredients during processing.

Natto presents an interesting case: it is produced by bacterial fermentation rather than fungal fermentation, but raises no specific concerns under any major religious dietary law. The primary limitation on natto's global spread is cultural palatability, not religious restriction.

Food uses & preparation

The culinary range of ancient fungal fermented foods is vast:

• Tempeh: Sliced and fried in oil until golden and crisp (tempe goreng); simmered in coconut milk with lemongrass and galangal (tempe opor); lacquered in sweet soy sauce and palm sugar (tempe bacem); crumbled into sambals; thinly sliced and deep-fried in a light batter (tempe mendoan). In Sundanese cuisine, tempeh appears in pecel — a salad with peanut sauce — and in various sayur (vegetable soups). In the West, it has been adopted for sandwiches, grain bowls, tacos, stir-fries, and as a bacon substitute when marinated and baked in thin strips.

• Miso: Dissolved into dashi stock for miso soup, the single most widely consumed prepared dish in Japan; used as a marinade for fish (misozuke), as a glaze for eggplant (dengaku), as a seasoning in stews and braises, stirred into ramen broth, mixed with butter as a compound for steak, used in vinaigrettes, blended into ice cream, and incorporated into confectionery. The spectrum from white (shiro) miso — mild, sweet, young — to red (aka) miso — dark, intense, two to three years old — gives miso a culinary range that few single ingredients can match.

• Oncom: Fried, grilled over charcoal, incorporated into Sundanese dishes like tutug oncom (cooked rice mixed with grilled oncom), used as a filling for savory pancakes, or simmered in light broths.

• Natto: Eaten over hot rice with karashi mustard, soy sauce, and thinly sliced green onion; used as a filling in maki rolls (natto maki); incorporated into okonomiyaki batter; served in cold soba; occasionally used as a pizza topping in Japan, a combination that reliably horrifies Japanese culinary traditionalists.

Ecological role

The ancient fermented fungal food tradition is, from an ecological standpoint, among the most efficient protein production systems humans have ever created. Tempeh production converts soybeans (already a highly efficient crop protein source) into a product with substantially higher protein bioavailability through the enzymatic action of the Rhizopus mold. Oncom takes agricultural waste — the press cake left after oil is extracted from peanuts or coconut — and produces food from it. No additional land is required. No additional water is required beyond what the fermentation process itself uses.

This efficiency prefigures what the modern mycoprotein industry aspires to: protein production that is substantially decoupled from the land, water, and emission costs of conventional livestock agriculture.

Ethical dimensions

The ancient fermented fungal food tradition raises few of the ethical questions that modern novel protein production generates, precisely because it developed organically from existing agricultural systems and culinary cultures. The ethical questions it does raise are primarily questions of appropriation and commercialization: as tempeh has moved from Javanese kitchens to Western supermarket shelves, the profits have largely accumulated to Western food companies, while the Javanese farmers and food artisans who maintain the living tradition receive little recognition or economic benefit.

The parallel with Quorn is instructive. The Quorn mycoprotein was developed in England, patented by an English company, and sold globally with almost no acknowledgment of the Asian fermented fungal food tradition it mechanically resembles. This is not industrial espionage — the Fusarium venenatum used in Quorn is a different organism from the Rhizopus and Aspergillus used in Asian fermented foods, and the Quorn process was independently developed. But the cultural framing matters: a product marketed as revolutionary and novel in the West was, in its basic concept, a replication of something that had existed in Southeast Asian kitchens for a millennium.

The future

The ancient fermented fungal food tradition is experiencing a paradoxical moment: it is simultaneously being rediscovered by Western food culture as a health food and protein source, while the artisanal and small-scale production systems that have maintained it are under economic pressure from industrial production. In Indonesia, artisanal tempeh producers using traditional bamboo-and-banana-leaf fermentation systems compete directly with large-scale industrial tempeh factories. The flavor and texture of traditionally produced tempeh — firmer, more complex, with a deeper fungal aroma — is measurably different from the industrial product, but industrial tempeh costs less.

At the same time, the fermented fungal food tradition is increasingly being cited by food scientists and food entrepreneurs as a model and a resource. Companies working on mycoprotein fermentation explicitly reference the tempeh tradition as validation that fungal food is not speculative — it is proven, at scale, across centuries, in multiple cultures.

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