Step 1

In a small pan simmer the mirin and sake for a minute, remove from heat and cool to room temperature.

Step 2

Combine the citrus juice, soy sauce, vinegar, water, kombu and mushrooms along with the mirin-sake mixture in a jar or container. Steep overnight.

Step 3

Strain through a fine strainer or double layer of cheesecloth.

Step 4

Refrigerate for up to a couple weeks.