Ume (Prunus mume) is a fruit that’s been commonly referred to as a plum but actually is a species of apricot. There’s evidence of the Ume (originally called Ubai) having been used as a traditional medicine in China 2,000 years ago, as a dried smoked fruit.
However, when the Japanese discovered the ume, they modified the processing methods and added two essential ingredients–salt and red shiso (beefsteak) leaves.
Since the 10th century, the Japanese have used Umeboshi as a healthy tonic, food preservative, antibacterial aid, and as an energy enhancer for Samurai warriors.
There’s a traditional Japanese saying that states: “By taking Umeboshi in the morning, you will be protected against evil spirits all day.”
For 1,000 years, Japanese cuisine and folk medicine included using the Umeboshi for purifying water, curing food poisoning, reducing fevers, and protection from fatigue, general malaise, and widespread diseases.
The Ume plum is harvested near the end of June when the plums are just beginning to develop their sweetness. The plums are cleaned, and then placed in large tubs with alternating layers of sea salt. The salt draws the juice from the plums and produces brine in the tubs. The plums begin their pickling while being submerged in the brine for two months. The ume plums are then removed, placed on racks and left outside to sun dry for three to five days depending on the weather. This sun-drying stage marks the official birth of “Umeboshi”, which literally means dried ume.
The Umeboshi are placed in vats where they mature for between several months up to one year. The coloring process begins when the matured Umeboshi are placed back in the brine along with alternating layers of red shiso leaves. They remain there for one to two months during which time their color changes from a sun-dried earthy color to pinkish-red.