Citrus junos or yuzu (from Japanese ユズ) (or more precisely, Citrus × junos [C. reticulata × C. ichangensis]) is a citrus fruit and plant in the family Rutaceae. It is called yuja (from Korean 유자) in Korean cuisine context. Both Japanese yuzu and Korean yuja are cognates of Chinese yòuzi (柚子), but the Chinese word means pomelo. Yuzu is called xiāngchéng (香橙) in Chinese.
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) in many regards; they share a similar mandarin-ichang papeda ancestry, though yuzu eventually ripen to an orange colour, and there are subtle differences between the flavours of the fruit.
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 at least as low as -9 °C (15 °F) where more sensitive citrus would not thrive.
It is also known that growth is slow, sometimes called in a Japanese phrase, “Peach and Chestnut, 3 years. Persimmon, 8 years. Big dummy Yuzu, 18 years.” For this reason, in cultivation, grown from seed takes more than ten years to fruit, so in order to shorten the period to fruit, it is often made to be able to harvest in a few years with grafting to Karatachi.
Varieties and similar fruits
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”).
The yuzu’s flavour is tart, closely resembling that of the grapefruit, with overtones of mandarin orange. It is rarely eaten as a fruit, though in the Japanese cuisine its aromatic zest (outer rind) is used to garnish some dishes, and its juice is commonly used as a seasoning, somewhat as lemon is used in other cuisines.
Yuzu is often combined with honey to make yuzu hachimitsu (柚子蜂蜜)—a kind of syrup that is used to make yuzu tea (柚子茶) or as an ingredient in alcoholic drinks such as the yuzu sour (柚子サワー).
Yuzu has also been used extensively in the flavoring of many snack products, such as Doritos.
In Korean cuisine, yuja is most commonly used to make yuja-cheong (yuja marmalade) and yuja tea. Yuja-cheong can be made by sugaring peeled, depulped, and thinly sliced yuja, and yuja-cha (yuja tea) can be made by mixing hot water with yuja-cheong. Yuja-hwachae (yuja punch), a variety of hwachae (fruit punch), 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.
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-  Archived November 15, 2006, at the Wayback Machine
-  Archived September 28, 2007, at the Wayback Machine
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- Emi, Doi (December 21, 2017). “Soaking and Seasoning: The Aromatic Pleasures of “Yuzu““. Retrieved December 22, 2017.
Yuzuyu dates from the Edo period (1603–1868) and may have been partially inspired by a form of Japanese wordplay called goroawase—the characters for “winter solstice” (冬至) and “hot-spring cure” (湯治) can both be read as tōji.
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- “Yuzu Wisely – Japan’s power citrus is a welcome cocktail alternative”, The Tasting Table, August 29, 2006
- Photo of a bottle of yuzu juice
- “Food Marketers Put Taro, Yuzu In Recipe For Growth”, by Sonia Reyes, from Brandweek, June 26, 2006
- “Cooks Look for Answers to Citrus Freeze”, from National Public Radio Weekend Edition Sunday, January 28, 2007