Clean and peel the ginger, then slice it thinly with a potato peeler.
Sprinkle ½ teaspoon of Kosher salt over the sliced ginger and leave it for 5 minutes.
Transfer the ginger to a pot of boiling water and cook for 1–3 minutes. Remove it after 1 minute for a spicier result, or leave it for 2–3 minutes for a milder flavour.
Drain the ginger well, spread the slices in a single layer on a clean tea towel or kitchen paper, pat them dry, and transfer to a sterilised jar.
Amazu
In a small pot, combine the rice vinegar, granulated sugar, and Kosher salt. Bring it to a boil, then simmer until the strong vinegar smell fades before turning off the heat.
When slightly cool, pour the liquid over the sliced ginger in the jar. Close the lid, let it cool, and refrigerate.
Recipe Notes
If you find young ginger with pale pink tips, the colour will start to show after a few hours in the amazu. By the next day, the slices develop a deeper pink tone without any colouring. Commercial versions are often dyed to achieve the same look.
Homemade pickled ginger keeps well in an airtight container in the refrigerator for up to 1 year.