2. Suppai: The Secrets of Japan's Sour Treats

In Japan, the word for sourness is suppai. Since ancient times, people in Japan have preserved foods through fermentation. Sour Japanese tastes include vinegar, pickled plums and yuzu, a citrus fruit. Sour Japanese foods are often tied to culture and tradition. In one example, we see how, in Okinawa Prefecture, the juice of the shikwasa, another citrus fruit, is used to wash traditional bashofu cloth.