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.
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.