Velvety green ume
, perhaps the quintessential Japanese
fruit, appear in early summer. Although generally referred to in Western languages as the Japanese plum
, the ume is actually a variety
A fresh, plump ume looks very sweet but is actually extremely sour and is seldom eaten raw (and probably never twice). Instead, it is cured in salt and then dried in the sun for several days to create wrinkled pink umeboshi.
First, ume are pickled in tubs of salt. Weights are placed on the fruit in the tubs, and after about 20 days the fruit is removed and spread out on mats under the sun. This process is repeated several times, and finally red shiso (perilla) leaves are added to the tubs to add fragrance and a soft reddish colour. The end result - umeboshi - can be kept for several years; in fact, the older they get, the more mellow and nuanced their flavour.
The umeboshi has been highly valued from ancient times for its medicinal properties. The fruit has the reputation of being germicidal, and is thus placed with rice in bento (box lunches) to prevent spoiling. In any case, it perfumes the rice and is delicious.
It is very high in vitamin C, and so traditionally it is said that eating one umeboshi a day is said to ensure good health by stimulating the appetite and aiding digestion. Its also considered an effective remedy against fatigue. On New Year's Day, an umeboshi is placed in the first morning's tea to assure good health all year long.
It also conveys an interesting tang to cool or warm saké.