The word tofu translates as curdled milk, and tofu is made by coagulating soy milk and pressing the resulting curds into solid white blocks of varying softness (silken, soft, firm, extra firm and super firm). Dried soybeans are first soaked in water, then crushed, boiled and separated into soft pulp (okara) and soy milk. Salt coagulants, calcium or magnesium chlorides and sulfates, are added to the soy milk to separate the curds from the whey and the soy milk is then poured into molds to allow the whey to drain off. The resulting soft cakes are then cut into squares and stored under water until they are sold.
Tofu is a traditional component of East and Southeast Asian cuisines. In the West, it is often used as a meat substitute. It’s subtle taste and spongy texture allow it to absorb the flavors of seasoning and marinades. Tofu is low in calories and high in protein, iron and calcium or magnesium, depending on manufacturing methods. It can be grilled, deep fried, simmered, stir fried, steamed or eaten fresh and it is often served with sweet or savory toppings.
The first record of tofu making is in China during the Han Dynasty 2,000 years ago. Some writers cite a popular legend that a Chinese cook discovered it when he added nigari seaweed to soy milk and accidentally curdled it. Others attribute the invention to Prince Lui Ari (179-122 BC) of Anhui Province. Tofu was introduced to Japan during the Nara period (710-794). From there it spread to Southeast Asia, possibly accompanying the spread of Buddhism since it offered an important source of protein in a vegetarian diet.