How is soya created? Unraveling the Process from Soybean to Product

November 12, 2025 •

4 min read

Archaeological evidence suggests soybeans were first domesticated between 6,000 and 9,000 years ago in north-central China. Today, this ancient legume is the foundation for an incredible variety of foods, but few know the intricate journey that answers the question: how is soya created?

Quick Summary

The process begins with the cultivation and harvesting of soybeans, followed by multi-stage processing that separates oil and meal. These raw components are then transformed into a wide range of unfermented foods like soy milk and tofu, or fermented products such as tempeh and soy sauce.

Key Points

Soya Origin: Soybeans were domesticated in ancient China over 6,000 years ago and have become a global dietary staple.
Harvest and Primary Processing: The creation begins with cultivating and harvesting soybeans, followed by cleaning, dehulling, and oil extraction to produce oil and protein-rich meal.
Oil Extraction Methods: Oil can be extracted using highly efficient solvent methods or less efficient but simpler mechanical pressing techniques.
Unfermented Products: Soy milk is made by grinding and filtering soaked soybeans, and tofu is produced by coagulating soy milk curds.
Fermented Products: Tempeh, soy sauce, and miso are traditional fermented products made with specific molds or bacteria for distinct flavors and textures.
Versatile Ingredient: Soya's versatility allows for a wide array of food applications, from liquid beverages and solid curds to savory sauces and protein powders.

The creation of soya is a complex and fascinating journey that begins in the field with the cultivation of the humble soybean and ends with a diverse array of finished food products. This process involves a series of meticulously controlled steps, including agricultural practices, primary processing, and secondary manufacturing, to unlock the full potential of this protein-rich legume.

Cultivation and Harvesting: The Foundation

The entire process hinges on successful soybean cultivation. Soya beans thrive in temperate climates and require fertile, well-drained soil. The cultivation process includes:

Planting: Seeds are typically sown between late spring and early summer in rows. Inoculation with Rhizobium bacteria is essential for nitrogen fixation, which reduces the need for nitrogen fertilizers.
Growth: The plants pass through vegetative and reproductive stages, with flowers appearing roughly six weeks after planting and pods forming afterward.
Harvest: Harvesting occurs in the autumn once the pods have matured and the plant's leaves have fallen off. Combines are used to cut and collect the soybean plants, separating the beans from the pods and stalks.
Cleaning and Storage: The harvested beans are cleaned to remove debris and stored in low-humidity environments to prevent spoilage.

Primary Processing: Deconstructing the Soybean

Once harvested, the soybeans are ready for processing to separate their key components: oil and meal. This is a critical step that prepares the material for further refinement or use in animal feed.

Cleaning and Dehulling: Raw soybeans are cleaned to remove impurities. Next, they are cracked and dehulled to remove the outer seed coat, which increases the protein concentration of the meal.
Conditioning and Flaking: The dehulled beans are heated and rolled into thin flakes. This step is crucial as it maximizes the surface area, which improves the efficiency of oil extraction.
Oil Extraction: The oil is removed from the flakes. This is most commonly done using a solvent extraction method with hexane, which yields a high percentage of oil. Alternatively, mechanical pressing can be used, though it is less efficient for soybeans.
Post-Extraction Processing: The extracted oil is collected for further refining, while the remaining defatted flakes are toasted, dried, and ground into soybean meal or flour. This meal is a valuable source of protein for livestock feed and human food applications.

Creating Diverse Soya Products: Unfermented

The initial processed soy ingredients serve as the basis for a wide range of unfermented products.

Soy Milk: One of the most popular unfermented products, soy milk is made by soaking and grinding soybeans in water. The mixture is then boiled and filtered to remove the solid pulp, or okara, leaving behind the milky liquid.
Tofu: Tofu is essentially coagulated soy milk, similar to how dairy cheese is made. A coagulant, such as calcium sulfate or magnesium chloride, is added to heated soy milk, causing the curds to separate from the whey. The curds are then pressed to varying degrees to achieve different textures, from silken to extra-firm.

Creating Diverse Soya Products: Fermented

Fermentation is a traditional method, particularly in East Asian cuisine, that transforms soy into products with unique flavors and textures.

Tempeh: Originating in Indonesia, tempeh is made from fermented whole soybeans. The beans are cooked, dehulled, and inoculated with a Rhizopus mold culture. The mold binds the beans together into a firm, nutrient-dense cake over 24 to 48 hours.
Soy Sauce: This liquid condiment is created through a complex fermentation process involving cooked soybeans, roasted wheat, and a mold culture (Aspergillus oryzae). The mixture, or koji, is mixed with salt brine and allowed to ferment for several months. The resulting mash is then pressed, pasteurized, and bottled.
Miso: This thick, savory paste is made from fermenting soybeans, salt, and koji. It is a fundamental seasoning in Japanese cooking used for soups, sauces, and marinades.

Comparison of Soya Processing for Oil & Meal


Feature	Mechanical Pressing	Solvent Extraction
Efficiency	Lower oil yield (approx. 75%)	Very high oil yield (nearly 100%)
Equipment	Screw-shaped expellers and presses	Large-scale, chemical-based extraction plants
Byproduct	Oil-rich press cake (prone to rancidity)	Defatted, heat-treated soy meal
Scale	Better for smaller-scale operations	Dominant for large, commercial production
Heat Generation	Generates significant heat	Less heat generated during extraction
Safety	Safer process, no flammable solvent	Requires strict safety protocols due to flammable hexane

Conclusion: The Ultimate Versatility

The process of creating soya is a testament to the versatility of the soybean. From a simple legume cultivated thousands of years ago, it has become a cornerstone of global food systems, providing high-quality protein and oil for a vast range of products. Whether through unfermented techniques to produce the soft texture of silken tofu or the liquid consistency of soy milk, or via fermentation to develop the complex umami of soy sauce and tempeh, the transformation from bean to final product is a precise and scientific art. This extensive processing ensures that soya remains one of the world's most valuable and widely utilized crops, adapting to diverse culinary and industrial needs.

For a deeper look into the botanical classification of the soybean, you can refer to its Wikipedia page on Glycine max.

Frequently Asked Questions

The primary raw material for creating soya products is the soybean, a legume scientifically known as Glycine max.

After being harvested with a combine, the soybeans are cleaned to remove debris and stored under low-humidity conditions to prevent mold growth.

Soy milk is produced by soaking raw soybeans in water, grinding them into a slurry, boiling the mixture, and then filtering out the remaining solids, known as okara.

Tofu is made from coagulated soy milk, resulting in a soft curd that is pressed into blocks. Tempeh is made from fermenting whole, cooked soybeans with a mold, which binds them into a dense, firm cake.

Soy sauce is made by fermenting a mixture of cooked soybeans, roasted wheat, and salt brine with specific molds and yeasts over several months. The mash is then pressed to extract the liquid.

No, soya can be processed into both fermented and unfermented products. Tofu and soy milk are examples of unfermented products, while tempeh and soy sauce are fermented.

After the oil has been extracted from soybeans, the remaining high-protein meal is toasted, dried, and ground. It is primarily used as a key protein source for animal feed but is also processed for human consumption.