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Soy Milk

Common

East Asia; now consumed worldwide

A soybean-based beverage traditionally produced by soaking and grinding soybeans with water, followed by separation and heating.

About Soy Milk

Soy milk is a plant-based beverage made from soybeans (Glycine max), a legume native to East Asia. It is one of the oldest plant milks in the world — soy milk has been produced and consumed in China for at least 1,500 years, with references to it appearing in texts from the Song Dynasty (960–1279 CE). The 19th-century Chinese scholar Li Yuying is often credited with establishing the first industrial soy dairy in Paris in 1910, bringing soy milk to European attention. It has since become the most widely consumed plant milk globally by volume, particularly in East and Southeast Asia.

Soy milk is produced by soaking whole dried soybeans in water, grinding them, boiling the mixture, and straining out the fibrous okara (the solid residue). The resulting liquid is white, smooth, and mildly beany in flavour when made traditionally. Modern commercial soy milk often uses additional processing steps including enzymatic treatments and flavouring to produce a more neutral, less beany product. Commercially fortified soy milk is available in sweetened, unsweetened, vanilla, and chocolate varieties, as well as low-fat and full-fat formulations.

Soy milk is nutritionally the closest plant milk to cow milk among all mainstream options — it provides comparable protein (approximately 6–8g per cup), similar calcium when fortified, and a more complete amino acid profile than any other plant milk. It is the most widely recommended dairy milk substitute by dietitians and health organisations for people who cannot consume dairy but need to maintain protein and calcium intake. The Codex Alimentarius does not classify soy milk as a "milk" under its dairy standards, but it is regulated as a soy beverage in most markets.

Sources & Further Reading

USDA FoodData Central — Soy Milk (Foundation Food) (current search) — Current USDA database search for the named food; select the matching product/data type because formulations and database records can change.
FAO FAOSTAT — Soybean Production Data — FAO statistical database for global soybean production, trade, and food use by country
PMC — Soy Isoflavones and Estrogenicity: 2024 Systematic Review — Systematic review finding no significant effect of soy isoflavones on several measures of estrogenicity in postmenopausal women; notes that isoflavone content varies substantially by food type and processing method
PMC — Commercial Plant-Based Milk Alternatives: Fatty Acids and Protein Digestibility — Beverage-level study that analyzed commercial almond, coconut, hazelnut, hemp, oat, quinoa, rice, and soy drinks; results are product-specific rather than universal.

Nutrition

Unsweetened soy milk (240ml / 1 cup, fortified) typically contains:

Calories~80–100 kcal

Fat~4 g

Protein7–8 g

Carbohydrates~4 g

Calcium~300 mg (fortified)

IsoflavonesPresent (plant phytoestrogens; structurally weaker than human oestrogen)

Soy milk is the closest plant milk to cow milk in protein content and amino acid completeness among all mainstream plant milks. It provides a complete protein with all essential amino acids. It is free of lactose and cholesterol. Soy contains isoflavones (phytoestrogens) — plant compounds that are structurally related to human oestrogen but bind to oestrogen receptors with much lower potency. A 2024 systematic review found no significant effect of soy isoflavones on several measures of estrogenicity in postmenopausal women; isoflavone content also varies substantially by product and processing method. The cited 2024 systematic review found no significant effect on several measures of estrogenicity in postmenopausal women; individual health questions should be considered separately. Soy is a major food allergen.

Common Uses

◌ Drinking◌ Coffee & lattes◌ Tofu making◌ Baking◌ Cooking◌ Cereal◌ Smoothies

Soy milk is the most versatile plant milk for dairy substitution. It steams and froths well for coffee drinks (its protein content gives foam stability). In Asian cooking, fresh soy milk (豆浆, dòujiāng) is consumed hot or cold, often with doughnuts (youtiao) as a traditional breakfast combination. Tofu is made by curdling hot soy milk with a coagulant — essentially the soy milk equivalent of cheesemaking. In baking and cooking, soy milk substitutes for dairy milk in virtually all applications due to its similar protein content.

Interesting Facts

Soy milk has been consumed in China for at least 1,500 years — it is one of the oldest plant milks in the world, predating commercial almond and oat milk by over a millennium.
Tofu (bean curd) is made from soy milk in exactly the same way that cheese is made from dairy milk — soy milk is heated, curdled with a coagulant (like calcium sulphate or magnesium chloride), and the resulting curds are pressed into blocks.
Soy milk contains phytoestrogens (plant oestrogens called isoflavones) — these compounds interact with oestrogen receptors differently from human oestrogen; the cited evidence should be read within the populations and outcomes actually studied.
Among all plant milks, soy milk has the closest protein content to cow milk — making it the recommended dairy substitute by most dietitians and health organisations for people who need to maintain protein intake.
The United States grows approximately one-third of the world's soybeans, though the majority of the US crop is used for animal feed and soybean oil extraction rather than direct human food consumption — soy milk uses a relatively small proportion of total soybean production.