Rice vinegar has as its base the sugars found in rice. These vinegars come in different types from different countries using slightly different processes.
In Japan, the vinegar may come from fermented rice or from adding rice to sake. Japanese rice vinegar tends to be a soft yellow in color or quite clear. Japanese rice vinegar is essential in the preparation of many traditional Japanese dishes—most notably sushi. It has a mild flavor in comparison to Chinese rice vinegar.
In China, you can find red and white rice vinegar. These varieties are stronger in taste and hue than the pale yellow Japanese variety. Red rice vinegar is both tart and sweet. You can add more sugar to sweeten it if you wish to replace black rice vinegar in a recipe. On its own, it is an excellent dipping sauce for seafood dishes and noodle soup. China is also home to black rice vinegar. The best, Chinkiang vinegar, originates in southern China. Glutinous or sweet rice is used, giving a strong dark vinegar with a slightly smoky taste. Like balsamic vinegars, the quality can vary substantially. Use as a dipping sauce with braised dishes.
Overall, rice vinegar is best used for dips. It is also excellent for making ketchups, soups, dressings and marinades.