Koon Chun Sauce Factory is one of the oldest and most respected food companies in Hong Kong. They make a wide variety of traditional sauces and condiments using no artificial preservatives, colors, or flavor enhancers. Chinese black vinegar is made from a mixture of rice, wheat, barley and sorghum. It is dark in color and has a complex, robust flavor that is both sweet and sour. It is commonly used as a condiment in Chinese cuisine in marinades, dipping sauces, and stir-fries. Black vinegar is most famously used as a dip for soup dumplings.