Tofu (Japanese: 豆腐, Hepburn: Tōfu, Korean: 두부; RR: dubu, Chinese: 豆腐; pinyin: dòufu) is a food prepared by coagulating soy milk and then pressing the resulting curds into solid white blocks of varying softness: silken, soft, firm, and extra (or super) firm.

[7][8][9][10] The earliest documentation of the word in English is in the 1704 translation of Domingo Fernández Navarrete's A Collection of Voyages and Travels, that describes how tofu was made.

[23] Since then, tofu has become a staple in many countries, including Vietnam, Thailand, and Korea, with regional variations in production methods, texture, flavor, and usage.

[25] Another theory suggests that the production method for tofu was discovered accidentally when a slurry of boiled, ground soybeans was mixed with impure sea salt.

The primary evidence for this theory is the etymological similarity between the Chinese term rǔfǔ (乳腐), which literally means "milk curdled", used during Sui dynasty (AD 581–618), for dishes with a consistency like yogurt or soft cheese, later influenced by Mongolian milk products and methods of production, and the term dòufu (豆腐, "beans curdled" ) or tofu.

The use and production of tofu were first limited to urban centers with influential Chinese minorities, such as Cebu or Tondo, but quickly spread to even remote native villages and islands.

[36] In 1908, Li Yuying, a Chinese anarchist and a vegetarian with a French degree in agriculture and biology, opened a soy factory, the Usine de la Caséo-Sojaïne.

For standard firm East Asian tofu, the soy curd is cut and strained of excess liquid using cheesecloth or muslin and then lightly pressed to produce a soft cake.

The addition of higher levels of calcium salts or a high protein content will contribute to forming a denser and more aggregated gel network which disperses more light, resulting in tofu with a whiter appearance.

Depending on whether the soy milk is gelled with bittern (magnesium chloride) solution or a suspension of gypsum (calcium sulphate), different types of unpressed tofu are produced.

Shredded dried tofu (豆干絲, dòugānsī in Chinese, or simply 干絲, gānsī), which looks like loose cooked noodles, can be served cold, stir-fried, or added to soup, as with Japanese aburaage.

[75] The films are collected and dried into yellowish sheets known as "soy milk skin" (腐皮, fǔpí in Chinese; 湯葉, yuba in Japanese).

[citation needed] The skin can also be dried into a product known as "tofu bamboo" (腐竹, fǔzhú in Chinese; phù trúc in Vietnamese; kusatake, Japanese), or into many other shapes.

Since tofu skin has a soft yet rubbery texture, it can be folded or shaped into different forms and cooked further to imitate meat in vegan cuisine.

Some foods, such as Burmese tofu, are not coagulated from the "milk" of the legume but rather set in a manner similar to soft polenta, Korean muk, or the jidou liangfen of Yunnan province of southwest China.

Egg tofu [ja] (Japanese: 玉子豆腐, 卵豆腐, tamagodōfu) (Chinese: 蛋豆腐, dàndòufu; often called 日本豆腐, Rìbĕn dòufu, lit.

The tofu known as goma-dōfu [ja] is made by grinding sesame into a smooth paste, combining it with liquid and kudzu starch, and heating it until curdling occurs.

[83] In many parts of China, fresh tofu is eaten with soy sauce or further flavored with katsuobushi shavings, century eggs (皮蛋 pídàn), and sesame seed oil.

The former is usually eaten plain in Chinese cuisine with garlic soy sauce, while the latter is either stuffed with fish paste to make Yong Tau Foo or cooked in soups.

In Japan, a common lunch in the summer months is hiyayakko (冷奴), silken or firm East Asian tofu served with freshly grated ginger, green onions, or katsuobushi shavings with soy sauce.

In the winter, tofu is frequently eaten as yudofu, which is simmered in a clay pot in kombu dashi, with vegetables such as Chinese cabbage or green onion.

In Japan, cubes of lightly coated and fried tofu topped with a kombu dashi-based sauce are called agedashi dōfu (揚げ出し豆腐).

Soft tofu that has been thinly sliced and deep fried, known as aburage in Japan, is commonly blanched, seasoned with soy sauce and mirin and served in dishes such as kitsune udon.

In Gifu Prefecture, there is a local specialty called komo-dofu, which consists of tofu that has been wrapped in a komo, or mat of woven straw, which leaves its imprint on the exterior.

Voids within the tofu develop during the boiling process, allowing the soup stock flavor to penetrate and giving it a distinctive porous appearance.

Chinese families sometimes make a steamed meatloaf or meatball dish from equal parts of coarsely mashed tofu and ground pork.

The tofu is boiled in coconut water, mixed with lengkuas (galangal), Indonesian bay leaves, coriander, shallot, garlic, tamarind and palm sugar.

Tofu and soy protein can be industrially processed to match the textures and flavors of cheese, pudding, eggs, bacon, and similar products.

In a reference amount of 100 g (3.5 oz), tofu supplies 76 calories, and is a rich source (20% or more of the Daily Value) of calcium, copper, iron, and manganese (table).

The soybean protein consists of many different subunits, which are sensitive to heat, pH, and ionic strength and become unevenly distributed among soluble and particulate fractions due to hydrophilic and hydrophobic interaction because of the amino acid composition.