Pickled tofu
Encyclopedia
Fermented bean curd also called sufu, fermented tofu, tofu cheese, or preserved tofu is a form of processed, preserved
Food preservation
Food preservation is the process of treating and handling food to stop or slow down spoilage and thus allow for longer storage....

 tofu
Tofu
is a food made by coagulating soy milk and then pressing the resulting curds into soft white blocks. It is part of East Asian and Southeast Asian cuisine such as Chinese, Japanese, Korean, Indonesian, Vietnamese, and others. There are many different varieties of tofu, including fresh tofu and tofu...

 used in East Asian cuisine
Asian cuisine
Asian cuisine styles can be broken down into several tiny regional styles that have roots in the peoples and cultures of those regions. The major types can be roughly defined as East Asian with its origins in Imperial China and now encompassing modern Japan and the Korean peninsula; Southeast Asian...

 as a condiment
Condiment
A condiment is an edible substance, such as sauce or seasoning, added to food to impart a particular flavor, enhance its flavor, or in some cultures, to complement the dish. Many condiments are available packaged in single-serving sachets , like mustard or ketchup, particularly when supplied with...

 made from soybeans. The ingredients typically are soybeans, salt, rice wine and sesame oil or vinegar, and are sold in jars containing blocks 2- to 4-cm square by 1 to 2 cm thick soaked in brine with select flavorings.

Serving

Fermented bean curd is commonly used as a condiment
Condiment
A condiment is an edible substance, such as sauce or seasoning, added to food to impart a particular flavor, enhance its flavor, or in some cultures, to complement the dish. Many condiments are available packaged in single-serving sachets , like mustard or ketchup, particularly when supplied with...

 and is consumed at breakfast to flavor rice, porridge
Porridge
Porridge is a dish made by boiling oats or other cereal meals in water, milk, or both. It is usually served hot in a bowl or dish...

, gruel
Gruel
Gruel is a food preparation consisting of some type of cereal—oat, wheat or rye flour, or rice—boiled in water or milk. It is a thinner version of porridge that may be more often drunk than eaten and need not even be cooked...

 or congee
Congee
Congee is a type of rice porridge popular in many Asian countries. It can be eaten alone or served with a side dish. Names for congee are as varied as the style of its preparation...

. Usually either several bricks are placed in a small bowl covered in the flavored brine or one to one half bricks are placed into a bowl. Then, chunks are broken off the brick and consumed with a mouthful of porridge or gruel. The brine may also be used for flavoring.
Fermented bean curd can also be added in small amounts, together with its brine, to flavor stir-fried or braised vegetable dishes (particularly leafy green vegetables such as water spinach
Ipomoea aquatica
Ipomoea aquatica is a semi-aquatic tropical plant grown as a leaf vegetable. It is known in English as Water Spinach, Water Morning Glory, Water Convolvulus, or by the more ambiguous names "Chinese spinach" and "swamp cabbage". It has many other names in other languages, such as "Phak bung" in Thai...

).

Characteristics

Fermented bean curd has a special mouthfeel
Mouthfeel
Mouthfeel is a product's physical and chemical interaction in the mouth, an aspect of food rheology. It is a concept used in many areas related to the testing and evaluating of foodstuffs, such as wine-tasting and rheology. It is evaluated from initial perception on the palate, to first bite,...

 similar to certain dairy products due to the breakdown of its proteins which takes place during the air drying and fermentation. Lacking strong flavor, fermented bean curd takes on the aroma and taste of its soaking liquid. The flavor is salty with mild sweetness. The texture and taste of fermented bean curd resembles a firm, smooth paste not unlike creamy blue cheese
Blue cheese
Blue cheese is a general classification of cow's milk, sheep's milk, or goat's milk cheeses that have had cultures of the mold Penicillium added so that the final product is spotted or veined throughout with blue, blue-gray or blue-green mold, and carries a distinct smell, either from that or...

. (Indeed, this kind of tofu is sometimes called "Chinese cheese" in English). Refrigerated, it can be kept for several years, during which time its flavor is believed to improve.

Varieties

White (bái) preserved bean curd (fǔrǔ) is the most common type and can be described without the white adjective. The flavor, color and aroma can be altered using various combinations of spices and seasoning in the brine with alterations in the commonly used combination of 10% rice wine and 12% salt. Those with no alcohol produces "small cheese cubes" (hih-fang) while those with double the alcohol content produces "drunken cheese" (tsui-fang). This variety is also available with chili and/or sesame oil. Seasonings can include anise, cinnamon, lemon juice
Lemon juice
The lemon fruit, from a citrus plant, provides a useful liquid when squeezed. Lemon juice, either in natural strength or concentrated, is sold as a bottled product, usually with the addition of preservatives and a small amount of lemon oil.-Uses:...

, lemon zest, dried shrimp, and ham. In addition, one can also obtain the curd dried, and without brine, which are then sold in paper cartons.

Red fermented bean curd , incorporates red yeast rice (cultivated with Monascus purpureus
Monascus purpureus
Monascus purpureus is a species of mold that is purplish-red in color...

) with the brining liquor for a deep-red color and distinctively thickened flavor and aroma. This variety may also contain chili. A popular derivative of this variety has an appearance of ketchup and is seasoned with rose essence, caramel and natural sugar.

Stinky fermented bean curd is fermented for over six months and is also popular due to its strong creamy flavor. However due to its strong acrid smell, this variety is an acquired taste. Note that stinky sufu differs from stinky tofu
Stinky tofu
Stinky tofu or chòu dòufu is a form of fermented tofu that has a strong odor. It is a popular snack in East and Southeast Asia, particularly mainland China, Taiwan and Hong Kong and in East Asian enclaves elsewhere where it is usually found homemade, at night markets or roadside stands, or as a...

 in appearance, consistency and salt content. Stinky sufu are made in the same cube-like shapes and has a similar smooth soft creamy texture as regular white sufu. In Taiwan, a green version is popular and made with sake lees, crushed leaves and a green mucor mold. It is then fermented for 12 hours and sold on the streets.

Chiang fermented bean curd (Chiang-doufu) is made with cubes of tofu soaked in either Chinese-style miso (Chiang) or soy sauce for several days. Usually reddish-brown in color and salty, it may be dried and fermented further and also may also be mixed with sake lees. In Japan, miso is used.

Production

In order to produce fermented bean curd, cubes of dried tofu are allowed to fully air-dry under hay and slowly ferment from aerial bacteria and fungal spores. Commercially available fermented bean curd is made by using dry firm tofu that has been inoculated with the fungal spores of Actinomucor elegans, Mucor sufu, Mucor rouxanus, Mucor wutuongkiao, Mucor racemosus
Mucor racemosus
Mucor racemosus is a fungal plant pathogen.Mucor racemosus has been known cause allergic reactions among some people. The fungus has been isolated in soft cheese Camembert.- External links :...

, or Rhizopus
Rhizopus
Rhizopus is a genus of common saprobic fungi on plants and specialized parasites on animals. They are found on a wide variety of organic substrates, including "mature fruits and vegetables", faeces, jellies, syrups, leather, bread, peanuts and tobacco. Some Rhizopus species are opportunistic agents...

 spp.. This freshly fermented tofu is known as mold tofu" (霉豆腐).

The dry fermented tofu is then soaked in brine
Brine
Brine is water, saturated or nearly saturated with salt .Brine is used to preserve vegetables, fruit, fish, and meat, in a process known as brining . Brine is also commonly used to age Halloumi and Feta cheeses, or for pickling foodstuffs, as a means of preserving them...

, typically enhanced with Chinese rice wine, vinegar, chili peppers or sesame oil, or a paste made of rice and soybeans. In the case of red fermented bean curd , red yeast rice (cultivated with Monascus purpureus
Monascus purpureus
Monascus purpureus is a species of mold that is purplish-red in color...

) is added for color. Fermented bean curd is generally sold in small glass jars.

History

According to Bencao Gangmu (Pen Ts’ao or Chinese Materia medica), by Li Shizhen (1596), the creation of soybean curd is attributed to Liu An
Liu An
Líu Ān was a Chinese prince and advisor to his nephew, Emperor Wu of Han of the Han Dynasty in China and the legendary inventor of t'ai chi...

 (179 – 122 BC), king of Wainan. Manufacture spread began during the Han Dynasty
Han Dynasty
The Han Dynasty was the second imperial dynasty of China, preceded by the Qin Dynasty and succeeded by the Three Kingdoms . It was founded by the rebel leader Liu Bang, known posthumously as Emperor Gaozu of Han. It was briefly interrupted by the Xin Dynasty of the former regent Wang Mang...

 in China after it was created. The date when the preservation of this curd began is unknown, but most likely was derived from those wishing to preserve the curd that had appeared to have gone bad.

The Food Encyclopedia, written by Wang Su-Hsiung (1861) of Qing Dynasty
Qing Dynasty
The Qing Dynasty was the last dynasty of China, ruling from 1644 to 1912 with a brief, abortive restoration in 1917. It was preceded by the Ming Dynasty and followed by the Republic of China....

, made reference to preserved bean curd as superior to difficult-to-digest, hardened tofu especially for the elderly, children and ill persons.

Comparisons with cheese

Both tofu and cheese are made from curds obtained from the coagulation of soybean milk and dairy milk respectively. However, soybean curds are formed from the chemical (calcium sulphate, bittern, acids etc.) destabilization of the micelles allowing protein bonding while cheese curds are created from the enzymatic (rennet
Rennet
Rennet is a complex of enzymes produced in any mammalian stomach to digest the mother's milk, and is often used in the production of cheese. Rennet contains many enzymes, including a proteolytic enzyme that coagulates the milk, causing it to separate into solids and liquid...

) hydrolysis of casein into para-casin. Tofu curds are then simply pressed and thus bland and highly perishable, while cheese is salted and ripened with microorganisms and thus flavorful and long-lasting. Consequently, fermented bean curd, which undergoes seasoning and fermentation, is the soybean equivalent to cheese.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK