Yuzu is a citrus fruit and plant in the family Rutaceae. It is believed to have originated in central China as a hybrid of mandarin orange and the ichang papeda. The yuzu is called yuja in Korean cuisine. Both Japanese yuzu and Korean yuja are borrowings of the Chinese yòuzi, though this Chinese word now refers to the pomelo.
Description
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 5.5cm and 7.5cm in diameter, but can be as large as a regular grapefruit. 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 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.
Cultivation
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. It is unusual among citrus plants in being relatively frost-hardy, due to its cold-hardy Ichang papeda ancestry, and can be grown in regions with winters as low as −9 °C where more sensitive citrus would not thrive.
Varieties and similar fruits
In Japan, an ornamental version of yuzu called hana yuzu "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. 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.
Use
Culinary use
Japan
Though rarely eaten as a fruit, yuzu is a common ingredient in Japanese cuisine, where the aromatic zest as well as juice are used much in the same way that lemons are used in other cuisines. The yuzu's flavour is tart and fragrant, closely resembling that of the grapefruit, with overtones of mandarin orange. It is an integral ingredient in the citrus-based sauce ponzu, and yuzu vinegar is also produced. Yuzu is often combined with honey to make yuzu hachimitsu —a kind of syrup that is used to make yuzu tea, or as an ingredient in alcoholic drinks such as the yuzu sour. Yuzukoshō, is a spicy Japanese sauce made from green or yellow yuzu zest, green or red chili peppers, and salt. It is used to make liquor and wine. Slivered yuzu rind is used to garnish a savoury, salty egg-pudding dish called chawanmushi, as well as miso soup. It is often used along with sudachi and kabosu. Yuzu is used to make various sweets including marmalade and cake. It is used extensively in the flavouring of many snack products, such as Doritos.
Korea
In Korean cuisine, yuja is most commonly used to make yuja-cheong and yuja tea. Yuja-cheong can be made by sugaring peeled, depulped, and thinly sliced yuja, and yuja-cha can be made by mixing hot water with yuja-cheong. Yuja-hwachae, a variety of hwachae, is another common dessert made with yuja. Yuja is also a common ingredient in Korean-style western food, such as salads.
Yuzu is also known for its characteristically strong aroma, and the oil from its skin is marketed as a fragrance. In Japan, bathing with yuzu on Tōji, the winter solstice, is a custom that dates to at least the early 18th century. Whole yuzu fruits are floated in the hot water of the bath, sometimes enclosed in a cloth bag, releasing their aroma. The fruit may also be cut in half, allowing the citrus juice to mingle with the bathwater. The yuzu bath, known commonly as yuzuyu , but also as yuzuburo, is said to guard against colds, treat the roughness of skin, warm the body, and relax the mind. The body of the taepyeongso, a Korean traditional oboe, close to the Chinese Suona or the Zurna, is often made from jujube, mulberry or yuzu wood.
