Rice Vinegar is the most popular in the cuisines of East and Southeast Asia. It is available in "white" (light yellow), red, and black varieties.
Once made from rice, it is usually now made from rice wine. Rice vinegar is slightly sweet & mild, and has a 4.3% acidity. Rice vinegar is made in both China & Japan. The Japanese prefer a light rice vinegar for the preparation of sushi rice and salad dressings. Japanese rice vinegars are mellow and mild, while vinegar from China is sharp and sometimes slightly sour.
Depending on the rice used, Chinese vinegars are red or white. Red rice vinegar traditionally is colored with red yeast rice. White rice vinegar has a mild acidity and a somewhat "flat", un-complex flavor. There is also a black Chinese vinegar, which is obtained from Black Glutinous Rice or Wheat, Sorghum & Millet.
Like Vinegars in the West, rice vinegar is often flavored. Soy Sauce and Mirin (sweet rice wine) can be added, along with spices and flavorings such as ginger root, dried bonito flakes, chilies, sesame seeds, onions, horseradish and mustard.