Ginger-Infused Koji Paste

1.In a clean, sterilized 1-quart glass jar, combine the dried rice koji and sea salt. Mix thoroughly with a clean spoon until the grains are evenly coated with salt.

2.Add the filtered water and the finely grated ginger to the jar. Stir well for about 1 minute to ensure the salt is fully dissolved and the ginger is evenly distributed; the mixture should resemble a thick, wet porridge.

3.Cover the jar loosely with a lid or a clean cloth secured with a rubber band to allow fermentation gases to escape. Place the jar in a cool, dark spot away from direct sunlight, ideally between 65-75°F (18-24°C).

4.Stir the mixture once a day with a clean spoon for 7 to 10 days. This introduces oxygen and ensures even fermentation; you will notice the rice grains softening and the liquid becoming milky and opaque.

5.Check for doneness after 7 days by pressing a grain of rice between your fingers; it should be soft and mash easily without a hard core. The paste is ready when it smells pleasantly sweet, slightly fruity, and fermented.

6.For a smooth glaze consistency, transfer the mixture to a high-speed blender and process for 30-60 seconds until completely smooth. This step is essential if you plan to use it as a fine coating for fish or delicate greens.

7.Transfer the finished ginger koji paste to an airtight container and store in the refrigerator. The cold temperature will significantly slow fermentation, and the paste will keep its bright, aromatic profile for up to 6 months.