Prepare the ginger rhizomes by scrubbing them under running water.
Cut stems off leaving the red part attached to rhizomes.
Slice the ginger rhizomes as thin as possible with a slicer *2
Boil water in a pot and parboil the sliced ginger.
Drain the parboiled water and scatter the sliced ginger on a cooling tray and set aside.
Place vinegar, sugar, salt and kelp dashi powder in a small saucepan over medium heat.
Turn the heat off when the sugar and dashi powder has dissolved.
Squeeze the sliced and parboiled ginger to remove excess water.
Place the ginger in a container and pour the vinegar mixture over while the vinegar is still hot. The ginger colour will turn to pink straight away.
Let it cool and refrigerate. You can start to eat after three hours pickled in the vinegar.
Notes
*1 You can find kelp (konbu) dashi powder from Japanese or Asian grocery stores. If you can not find Kombu Dashi Powder try online. *2 I set my slicer slice at 0.5mm (0.02inch).