THEY say you catch more flies with honey than vinegar - but they haven't tasted China's rich, mellow, sweet and sour vinegars. Gao Ceng talks to the chefs.

Chinese vinegars (cu 醋) are rich, varied and complex, they can be made with many ingredients and seasonings, and they are indispensable to a chef.

Xiaolongbao (小笼包 steamed dumplings stuffed with minced pork), hairy crab, sweet-and-sour soup, sweet-and-sour pork - eating them without vinegar is unthinkable.

Chinese vinegars are more than sour, tart and acidic, some are sweet, mellow and full-bodied, with a complex, lingering aftertaste.

"Compared with some Western vinegar made from fruits expressing the sour taste directly with a fleeting freshness, Chinese vinegar fermented from rice tastes deeper, with more layers of flavor," says David Du, chef de cuisine at Hyatt on the Bund.

Chinese vinegars are black, red or white and can be fermented from rice, glutinous rice, red yeast rice, sorghum, wheat, barley millet, sorghum, bran, malt and fruits. They often contain sugar and can be seasoned with salt, anise, cardamom and other spices. Many are aged, some for as long as 10 years, and many have a smoky flavor.

Chinese chefs use the word "chameleon" (bian se long 变色龙) to describe vinegar, which is diverse and versatile, containing layers of flavor that work with other seasonings and ingredients to create different tastes. It can be distinctive, it can be low-key.

Vinegar is probably the oldest condiment in China, dating back to the Xia Dynasty (c. 21st century-16th century BC). It is said that the interesting, sour liquid was accidentally invented in a winery by Hei Ta, son of Du Kang, the legendary inventor of Chinese rice wine.

In one story, Hei mistakenly added too much water during fermentation. In another, he save the lees and stored them, eventually opening them to discover aromatic and powerful vinegar.

Vinegar soon became popular and different regions developed different vinegars, fermenting their local produce.

Sorghum and millet were used in the north, glutinous rice in the south and wheat in central China, so colors range from dark black and ruby red to white and gold. The taste can be strong and rough, or fine and delicate, as in rice vinegars.

Hairy crab, if served without vinegar, is not hairy crab anymore. Without vinegar, many dishes are not the same.

They include xiaolongbao (steamed dumpling filled with minced pork and stock), jiaozi (饺子 boiled dumpling with meat filling), mixed noodle and hai zhe tou (海蜇头 tossed jelly fish).

"Vinegar is a versatile enhancer," says Dicky To, executive Chinese chef at The Peninsula Shanghai where he uses vinegar in summer appetizers.

In addition to intensifying flavor, vinegar can develop the delicate and sweet flavor in shellfish, cut the oil and grease in pork dishes, cover the earthy, fishy taste of river fish, and stimulate digestion when people eat too much.

Taste of first love

Chinese vinegar and sugar create the sweet and sour taste familiar to many Westerners whose first taste of Chinese food may be gu lao rou (咕咾肉), sweet-and-sour pork stir-fried with pineapple.

Chinese describe sweet and sour as "the taste of first love."

The tip of the tongue tastes sweetness, the sides taste sourness and the back tastes bitterness.

"We perceive the flavor in the tip, then the sides and the back so the sweet-and-sour taste connects seamlessly," chef To explains.

Both tang cu (糖醋 braising with vinegar and sugar) and gu lao (咕咾 stir-frying in sweet and sour sauce) are popular ways of cooking with vinegar and sugar.

Tang cu paigu (糖醋排骨) is pork rib deep-fried and braised with soy sauce, aged vinegar and sugar.

The pork, after being tenderized by the acid in vinegar and then deep-fried, is crisp outside and juicy inside. Soy sauce adds more roundness to the rich dish that has a balance of sweet and sour taste.

Sour and spicy tastes complement each other.

When sour vinegar meets spicy chili or pepper, the two strong tastes in combination are not so strong.

"Chinese vinegar acts like a good mediator," says chef Du at Hyatt on the Bund.

"The full-bodied sourness in vinegar relieves heat in dish," says Hua Chen, chef de cuisine at Grand Hyatt Shanghai.

Some classic dishes use vinegar to highlight sour-and-spicy flavor, and add a touch of sophistication.

In yu xiang rou si (鱼香肉丝 shredded pork with fish flavor), pork is stir-fried with spring onion, garlic and mushroom in sauce made from chili, vinegar, soy sauce and sugar.

"It features perfect balance in flavor, spicy, sour and sweet, without one overpowering another," says chef Chen at Grand Hyatt Shanghai.

Suan la tang (酸辣汤 sour-and-spicy soup) contains shredded mushroom, bamboo shoots and pork stewed with vinegar and black pepper.

Vinegar relieves some heat from the pepper but the dish is still hot and sour enough to make you perspire.

Sometimes a few drops of vinegar makes a big difference, elevating the dish to a higher level, while diners find it hard to tell if vinegar has been added.

"A little vinegar, probably several drops, makes a big difference," says chef To from The Peninsula Shanghai.

For men yuan ti (焖圆蹄 pig's feet simmered in soy sauce), a little vinegar doesn't change the taste but makes the pig's feet tender, fatty yet not greasy.

Buzzword

Eat vinegar 吃醋

Chi cu or eat vinegar is a common expression to mean a woman's romantic jealousy.

It dates back to the Tang Dynasty (AD 618-907) when it was recorded that Emperor Taizong decided to reward his chancellor Fang Xuanling by giving him a choice of beautiful women from his concubines.

Fang's wife was angry and jealous, however, and refused to accept a new woman to share her husband's bed.

The emperor himself was annoyed and gave Fang's wife a choice: either accept new, young lovers for her husband - or drink a cup of poisoned wine and end her life.

She chose to drink poison - which turned out to be vinegar in the emperor's test of her courage and devotion to her husband.

Hence, eating vinegar has come to signify a woman's romantic jealousy.

Fang finally didn't get his new concubines, but his wife went down in history.

Famous Chinese vinegars

Chinese vinegars have a range of flavors, aromas and colors, but there are four basic types. Chefs recommend the right vinegar for various dishes.

Zhenjiang Xiang Cu 镇江香醋

Zhenjiang aromatic vinegar, also known as black vinegar, is dark, intensely aromatic with a mellow sweetness.

Made with glutinous rice, it is comparatively low in acidity, with a distinctive aroma. It is commonly used as a dipping sauce for hairy crabs and various dumplings. Its sweetness brings out the natural sweetness in crab, meat and other food.

Shanxi Chen Cu 山西陈醋

Shanxi aged vinegar, the most famous vinegar in north China, is dark brown, with a rich and intense acidity, smoky flavor and a lingering aftertaste. It's made from sorghum and wheat and generally aged for 10 years.

It is commonly used as a sauce for seafood or river fish, as well as making tang cu (sweet-and-sour) and suan la (sour-and-spicy) dishes because its intensity covers fishy odors and is not overwhelmed by strong spices and seasonings.

Sichuan Fu Cu 四川麸醋

Sichuan wheat vinegar is famous for the addition of more than 30 herbs, such as danggui (Chinese angelica), mint and cardamom during fermentation.

Because of its herbal flavor, it's not suitable for dipping but is mixed with other seasonings. It's commonly used in Sichuan dishes such as yu xiang rousi, adding complexity to the flavor.

Hong Cu (red vinegar) 红醋

This ruby red vinegar, made from red yeast and glutinous rice, is popular in Cantonese dishes.

The taste is not deep and lingering, but light and fresh. It's commonly sprinkled over shark fin soup and served with deep-fried chicken as a dipping sauce.

Classical dishes using Chinese vinegar

Song shu guiyu (sweet-and-sour fish)

松鼠桂鱼

Deep-fried mandarin fish is topped with sweet and sour sauce and sprinkled with crushed nuts. The sauce includes vinegar (white vinegar for not influencing the color), tomato sauce, and lime juice for a bright orange color and hint of citrus.

Xiaolongbao (steamed dumplings)

小笼包

Dumplings are filled with hairy crab meat and roe. When dipped in rice vinegar or Zhenjiang aromatic vinegar, the natural sweetness of the crab is highlighted, while the earthy taste is covered.

Venue: Club Jin Mao, Grand Hyatt Shanghai

Address: 86/F, 88 Century Ave, Pudong

Tang cu paigu (pork braised with vinegar and sugar)

糖醋排骨

In this signature dish, the pork is braised with Shanxi aged vinegar and sugar, giving the pork a shiny coffee color. Ribs are crisp outside, juicy inside, and the sweet and sour tastes are balanced with the rich pork.

Suan la tang (sour-and-spicy soup)

酸辣汤

Based on a classical recipe - shredded mushroom, bamboo shoots and pork stewed with Zhenjiang aromatic vinegar and black pepper - chef adds pieces of fish that melt in the mouth and gelatinous, "bouncy" sea cucumber with a bland taste. The result is rich and complex texture and flavor.

Venue: Xin Da Lu China Kitchen, Hyatt on the Bund

Address: 1/F, 199 Huangpu Rd

Gu lao shi ban (sweet-and-sour garoupa)

咕咾石斑

Firm, tender garoupa is deep fried with diced pineapple, dried apricot and bell pepper in a sauce of vinegar and sugar. The apricot adds a crunchy texture.

Liang ban mi xian (rice noodle in sauce)

凉拌米线

The rice noodle, topped with geoduck (saltwater clam), is chilled in advance for a "springy" texture. The sauce is made with black vinegar, chili and garlic, with a taste that is deeply sour, slightly spicy and aromatic.

Venue: Yi Long Court, The Peninsula Shanghai

Address: 2/F, 32 Zhongshan Rd E1