Tofu, also known as soybean curd, is made by coagulating fresh hot soymilk with a curdling agent. The precise origin of the first tofu is disputed, but Ming Dynasty (1368-1644) herbalist Li Shizhen, in his classic pharmacopeia Compendium of Materia Medica, wrote that tofu was invented by King Liu An.

Around 164 BC, Liu An succeeded his father's title as King of Huainan in eastern China. He believed in immortal life and spared no effort chasing the elixir. In the process, he financed thousands of alchemists to refine the elusive pills that would give him eternal life. Once when the alchemists were making pills with soybean milk, they accidentally dropped in some plaster, and the milk became a soft, smooth delicious curd.

It was easy to produce and soon became very popular among the people, so although Liu An passed on without getting his immortal elixir, his name lives on as the accidental discoverer of tofu, now one of the most popular ingredients in Chinese cuisine.

In the Tang (AD 618-907) and Song (960-1279) dynasties, beancurd reached its peak of popularity, and its preparation soon spread to Japan and Korea, where it is still a main ingredient today.

In the history of tofu, two women become well known for their connections with tofu. One was young and beautiful, and the other was disfigured by a bad case of acne.

Tofu Xi Shi is a figure immortalized by Chinese revolutionary writer Lu Xun in one of his novels. Xi Shi was one of the renowned Four Beauties of ancient China, and in Lu Xun's novel, the woman selling tofu is young with silky eyebrows and a fair complexion. Customers buying tofu from her were charmed by her beauty and named her Tofu Xi Shi.

In contrast, the other woman linked to the tofu legends was the woman chef who produced mapo tofu, the numbing, spicy beancurd dish from Chengdu.

Traders, peddlers and porters always rested at her restaurant and provided tofu, beef and oil for her to cook for them.

Men make tofu, too. The Chinese war hero Guan Yu from the Three Kingdoms (AD 220-280) era was said to be a tofu maker before he enlisted in the army. Guan Gong (a respectful title) Tofu is a special dish very popular in Hubei province.

Now, of course, tofu has traveled far and wide from its homeland and become a part of international cuisine, providing a valuable source of vegetable protein for vegetarians, especially.