Yuzu: Japan's rare citrus with a tropical fruit twist

Where does yuzu come from?

Yuzu, Citrus × junos, is a citrus of Chinese origin, believed to be a hybrid of a wild mandarin and the Ichang papeda. As Wikipedia's article on yuzu explains, it was introduced to Japan and Korea during the Tang dynasty and is still grown there, and it has more recently been planted in New Zealand, Australia, Spain, Italy and France. Its Ichang papeda ancestry makes it unusually frost-hardy for a citrus.

Yuzu oil comes from the peel. In Japan, most of it is produced by hydrodistillation, mainly around Kōchi, and yields are low; French Wikipedia's page on yuzu essential oil quotes prices of around €1,000 per kilo in 2019, against €10 to €20 for lemon oil.

What does yuzu smell like?

Yuzu has a characteristically strong aroma, and its flavour closely resembles grapefruit with overtones of mandarin. Limonene dominates the oil, but its character comes from trace compounds: two aldehydes, 6-methyloctanal and 8-methyldecanal, two beta-ketols found in no other citrus, and a thiol typical of grapefruit. A sulfur compound also found in white wine and hops adds a tropical fruit note.

What does yuzu do in a perfume?

Perfumers prize yuzu, but Japanese output is too small to support a major international launch, so most yuzu fragrances are citrus blends within the citrus family, a family it shares with grapefruit and lemon. In Japan, the fruit also scents the bath: whole yuzu float in hot water on the winter solstice, a custom dating back at least to the early 18th century. Yuzu also flavours drinks such as yuzu tea, made with yuzu and honey.

What should you know about yuzu?

Yuzu oil is fragile: poor storage can strip away 38 to 93% of its monoterpene hydrocarbons, limonene included. Chemically it stands apart, too: a 2022 comparison of citrus coumarins groups it with grapefruit, far from lemon, lime and bergamot, and a 2023 study found none of 25 targeted photoactive coumarins in distilled yuzu oil, the only citrus peel oil tested with that result. The class on extraction methods compares distillation and cold pressing.