As one of the oldest foods of the ancient Chinese culture, Tofu has since become a staple food and major source of vegetable protein throughout the world due to its health benefits and rising popularity of vegetarianism. Like many ingredients in Japanese food, Tofu was introduced to Japan from China.
The manufacturing process of Tofu is relatively simple. Made from soybeans, the beans are boiled after having been soaked overnight and crushed until they reach a yogurt-like consistency. It is then separated into two parts. The first is a "bean-milk" or "tonyu" as it's known in Japanese, and the second a "bean pulp" or "okara." A gypsum is then added to the tonyu as a coagulant after which the warm milk is poured into a cheesecloth lined mold which sets the curd and allows for water drainage. When Tofu is strained in this manner, it leaves distinctive patterns on the base of the Tofu known in Japanese as "momen-goshi." "Kinu-goshi" is the softer, finer, and more delicate type of Tofu (silk strained). Kinu-goshi does not have these marks. It's made with a denser milk without draining the excess water. In both cases, they are suspended in water allowing them to cool and firm up.