Yuzu
The Yuzu is a little-known member of the citrus family that originated in China but that is used most frequently in Japan, where an ornamental version is also grown for its flowers. The New York Times has said that it has a "distinctive flavor and aroma, a complex blend of lime, lemon and grapefruit." It is, apparently, a hybrid of two other citrus varieties, the Ichang papeda and the sour mandarin orange. Its size varies, from that of a lemon to that of a grapefruit, and its skin color can be yellow, orange, or green. It is tart in flavor and is seldom eaten by itself, being used instead in various flavorings. Given its somewhat murky origins, its name is also ambiguous—references can be found in English for both the Yuku lemon and the Yuku orange.
Japan and Korea both make use of the yuzu in cooking, but to a greater in Japan than elsewhere. There its juice is bottled commercially and a yuzu vinegar is also produced, as well as liqueurs and wines. Chefs in New York City in the early days of the 21st century discovered the yuzu, and such celebrity restaurants as Jean George have begun using it in creative ways. [1]