Citrus junos

Yuzu (Citrus junos, from Japanese ユズ or 柚子) is a citrus fruit and plant in the family Rutaceae. It is called yuja (from Korean 유자) in Korean cuisine. Both Japanese yuzu and Korean yuja are cognates of the Chinese yòuzi (柚子), but the Mandarin word refers to the pomelo. Yuzu is called xiāngchéng (香橙) in Mandarin. The fruit looks somewhat like a small grapefruit with an uneven skin, and can be either yellow or green depending on the degree of ripeness. Yuzu fruits, which are very aromatic, typically range between 5.5 cm (2.16 in) and 7.5 cm (2.95 in) in diameter, but can be as large as a regular grapefruit (up to 10 cm (3.93 in) or larger). Yuzu forms an upright shrub or small tree, which commonly has many large thorns. Leaves are notable for a large, leaf-like petiole, resembling those of the related kaffir lime and ichang papeda, and are heavily scented. Yuzu closely resembles sudachi (a Japanese citrus from Tokushima Prefecture, a yuzu-mandarin orange cross) in many regards, though unlike the sudachi, yuzu eventually ripen to an orange colour and there are subtle differences between the flavours of the fruit. The yuzu originated and grows wild in central China and Tibet. It was introduced to Japan and Korea during the Tang Dynasty, and is still cultivated there. It grows slowly, generally requiring 10 years to fruit. To shorten duration to fruiting, it may be grafted with karatachi (P. trifoliata). It is unusual among citrus plants in being relatively frost-hardy, due to its cold-hardy C. ichangensis ancestry, and can be grown in regions with winters as low as −9 °C (15 °F) where more sensitive citrus would not thrive. In Japan, an ornamental version of yuzu called hana yuzu (花ゆず, 花柚子) 'flower yuzu' is also grown for its flowers rather than its fruit. A sweet variety of yuzu known as the yuko, only present in Japan, became severely endangered during the 1970s and 1980s; a major attempt has been made to revive this varietal in southern Japan. Another variety of yuzu in Japan, with knobby skin is called shishi yuzu (獅子柚子, literally 'lion yuzu'). Dangyuja, a Korean citrus fruit from Jeju Island, is often considered a type of yuzu due to its similar shape and flavour, but it is genetically a variety of pomelo. Though rarely eaten as a fruit, yuzu is a common ingredient in Japanese cuisine, where the aromatic zest (outer rind) as well as juice are used much in the same way that lemons are used in other cuisines. The yuzu's flavor is tart and fragrant, closely resembling that of the grapefruit, with overtones of mandarin orange.