Put the ● ingredients in a pot and bring to a boil to burn off the alcohol. Turn off the heat and add sugar and salt. Mix to dissolve.
Wash the sudachi well. Juice and strain through a tea strainer to remove the seeds. (If it's difficult to extract juice, microwave for 15 seconds first.)
When the mixture from Step 1 has cooled, add 3 thinly sliced sudachi and juice, put into a container and leave to mature in the refrigerator for 1 week.
After a week, strain the mixture through a cheesecloth or gauze, and it's done. Store in a non-plastic container.
Regular soy sauce based ponzu is mild and delicious, too. Recipe ID: 928081
Use the peel for salt... Recipe ID: 1599469
Story Behind this Recipe
I received a lot of sudachi citrus from a COOKPAD user I'm friendly with again this year. I learned how to make ponzu from another friend who is the head chef at a ryotei, and I modified the recipe.
This keeps for more than a month in the refrigerator. It may flame up in Step 1. Once the alcohol has burned off, the flames will die down but be careful of burns or setting your kitchen on fire. If you use a plastic container, it may melt because of the high acidity. I recommend storing the ponzu in a glass or ceramic container.