Sterilysing the preserving container by boiling in a large pot. Take them out and let it dry to set aside.
Wash Ume Plum fruits. *1
Pat dry the ume plum fruits with kitchen towel or cloths.
Place the ume plum in a ziplock bag and pour over the gin to disinfect.
Place some of the ume at the bottom of the sterilised preserving glass jar and add some of the salt. Repeat this to make layers of umeboshi and salt until the umeboshi is all used.
Place a weight on top of the last layer. I used baking beads inside a ziplock bag as a weight.
Store out of sunlight for a week. Check everyday if umezu (plum vinegar) is being produced and rising.
After one week, prepare the red shiso leaves to add to the plums.
After adding the leaves, set aside for 2 weeks.
Pick 3 consecutive sunny days to dry the umeboshi.
On day one remove the umeboshi from the jar and place onto a bamboo tray to dry. Make sure to leave a gap so they aren't touching. Squeeze the liquid out of the shiso leaves and spread the leaves out on the tray to dry too. Bring in the tray at night and place the leaves and the plums back into the jar with the liquid.
On day two repeat the same as day one. However, do not put the plums and leaves back into the jar. Leave them on the tray.
On day three repeat the same as day two. *3
Momi Shiso (massaged red shiso leaves) for colour
Wash the shiso leaves and drain the water as much as you can.
Sprinkle half of the salt amount on top of the leaves.
Toss the salt and shiso leaves together then massage the leaves with your hands.
Discard the dark purple liquid that comes out.
Sprinkle the remaining half of the salt over the shiso leaves and massage again. *2
Squeeze out the dark purple liquid from the leaves.
Place the shiso leaves into a small mixing bowl.
Add 1 tbsp of umezu (plum vinegar) from the jar of plums.
Add the leaves to the jar of umeboshi and leave for another 2 weeks.
*1 If you get green firm plums, leave them in room temperature covered with newspaper till the colour turns yellowish. Ripe is best!*2 This step removes the astringent taste from the red shiso leaves.*3 After 3 days of sun drying, place the umeboshi in a clean preserving jar and store them in a cool and dark place. You can eat them straight away, though it you let it mature for three month or longer, the taste will become mellower.