Japanese Food History and Culture

Yuzu and Mikan: Citrus Fruits in Japan

Citrus fruits such as oranges, lemons and grapefruits enjoy great popularity in Japan. They are found everywhere: juices, seasonings, desserts… Beyond their sweet or sour taste, they are also appreciated for their medicinal properties, and Japan is the home of the citrus bath. Supermarkets stocking their shelves with mandarin oranges is a familiar sight across the country and a sign of the coming Winter. Unsurprisingly, Japanese citruses go way back and are inextricably linked with the history of Sino-Japanese relationships. Today, we will take a look at the amazing variety of citruses in Japan, where they come from, and their place on the dining table.

Citrus fruits in ancient Japan: tachibana, yuzu and daidai

In Japan, cultivation and consumption of citrus fruits can be traced back to ancient times. The two oldest Japanese historical sources, the Kojiki (古事記, Records of Ancient Matters, 712 AD) and the Nihon Shoki (日本書紀, Chronicles of Japan, 720 AD), relate how a man named Tajima Mori went to a distant land to bring back a fruit granting eternal life for the emperor Suinin. It is thought to be the tachibana (橘), the oldest known Japanese citrus, although the exact definition of the fruit mentioned in the story is still being debated today.1 If Tajima Mori went overseas to find a citrus fruit around the 3rd century AD as the sources suggest, based on our knowledge of ancient Chinese medicine, he might have brought back a daidai (橙) bitter orange.2 Other legends related to the introduction and cultivation of citrus in Japan can be found in ancient works, but the most plausible origins are probably either immigrants from China and Korea or natural dispersion via migratory birds and sea currents.3 In time, other varieties would be introduced and crossbred with already present cultivars.
Due to their sourness, citrus fruits introduced during the Nara period such as the yuzu (柚子) were used for their medicinal properties rather than for their taste. Thought to help warm the body and ward off colds, there exists a custom of soaking in a bath with floating yuzu fruits during the Winter solstice that goes back to the Edo period. The yuzu was also used as a fragrance (for instance on kimono sleeves) thanks to its strong scent. In cooking, they were used as condiments to add sour accents to a dish. It is only with the later introduction of sweeter varieties of oranges during the Muromachi period that citrus fruits would gain more popularity as foods and ingredients.4 5

Kishū and unshū mikan

Although the word is attested since ancient times and its use has evolved, mikan (みかん) nowadays describes varieties of mandarin oranges widely consumed in Japan. Komikan (小みかん) mandarins, probably imported from the Zhejian province of China, were already cultivated in Yatsushiro (Higo province) and surrounding areas around the 12th-13th century.

Those komikan would be exported to the Kii province sometime before the 15th century, and by the end of the Muromachi period, the kishū mikan (紀州みかん) would become a local specialty. The mountainous slopes around the Arita area in particular lend themselves well to the culture of the mikan, and the Arita mikan would become a sought after commodity in the newly established capital of Edo.

However, the consumption of mikan would only really take off with the widespread cultivation of unshū mikan (温州みかん) in the latter half of the Edo period. They are named after the Japanese reading of Wenzhou, a Chinese city known for its citrus production, where this variety was thought to come from. However, recent research points to it being a native Japanese variety. Its birthplace is thought to be the Satsuma domain, in southern Kyūshū.

The unshū mikan might have been known since before the Edo period, but it wasn’t popular due to the fact it is a seedless fruit. Seeds representing fertility, eating an unfertile mikan was thought to invite bad luck and bring an end to one’s lineage. Despite this, as it is a sweet and easy to eat fruit, it started to gain popularity in the second half of the Edo period, and its cultivation subsequently spread. Nowadays, the unshū mikan and its variations are the most widely consumed mandarin oranges in Japan. It was also exported overseas from ports in Satsuma, which explains why it is also known as Satsuma mikan outside of Japan (not to be confused with the Satsuma imo).6

Common citrus varieties

Citrus fruits are the most popular in regions historically known for their production, such as Ehime, southern Kyūshū and Wakayama.7 Interestingly, it would seem the prefectures consuming the most mikan have also the lowest orange consumption in the country.8 This could be explained by the fact that oranges aren’t cultivated on a large scale in Japan and are mostly imported. They could act as a substitute for the mikan where local products are not readily available.
One of the specialties of Ehime prefecture, there are a lot of citrus varieties cultivated in the region such as the kiyomi, ponkan, shiranuhi (better known as dekopon) and iyokan.9 Kumamoto prefecture on the other hand produces 96% of the national output of the banpeiyu (晩白柚) pomelo cultivar as well as various other citrus fruits.10 Shizuoka prefecture does also have numerous citrus cultivations, and produces the sweet konta kumquat.11 Japanese lemons are mainly cultivated in Hiroshima prefecture, where they are often eaten with oysters, another local specialty.12 Finally, Okinawa has its own native citrus, the shīkuwāsā, often pressed and used for juices.

Modern day dishes and drinks

Various citrus fruits such as mikan, oranges, grapefruits, pomelos and kumquats are eaten raw for breakfast, dessert or as a snack, especially when in season. Juices and drinks are also very popular and can be found in stores and vending machines. Lemon soda is mixed with shōchū to make chūhai, a very popular drink at izakaya.

Slices of hard, sour citruses such as the sudachi and kabosu are often served along with karaage fried chicken or yakizakana grilled fishes to be squeezed on the food when eating, enhancing the flavor of the dish.

Yuzu and lemon flavored sweets are also popular, and it is common to see desserts such as baumkuchen or ice cream have seasonal citrus flavors.

Yuzu peels can be mixed with tōgarashi chili pepper and salt and left to ferment to make yuzukoshō (柚子胡椒), a popular condiment in Kyūshū. It is often used as a seasoning for meats such as yakitori grilled chicken, with udon noodles or with certain types of sashimi.

Another common condiment, ponzu (ポン酢), is made from citrus juice and vinegar. Mixed with soy sauce, it is used with a wide variety of dishes, for instance to add a light, sour note to nabe dishes like the chanko nabe or as a dipping sauce for katsuo no tataki.

Mikan are associated with oshōgatsu (お正月, New Year) and served along amazake at shrines and temples during the celebrations. A common oshōgatsu display is the kagami mochi (鏡餅), where a mikan with a green leaf on top is placed on a stack of two round mochi rice cakes.13

Gochisō sama deshita!