Sushi-Su (Seasoned Vinegar for Sushi Rice)
1 cup rice vinegar
3 tablespoons sugar
2 1/2 teaspoons salt
1 piece kombu, 2-inches square (optional)
Combine the vinegar, sugar, salt, and kombu in a small saucepan. Place the saucepan over medium-high heat and cook, stirring until the sugar and salt dissolve. When the mixture is clear, remove the saucepan from the heat and set it aside to cool. Discard the piece of kombu. Sushi-su can be stored in an airtight container in the refrigerator for up to 1 month.
How to Make Sushi Rice
1. Transfer the freshly cooked hot rice to a wide shallow bowl. Pour a small amount of the sushi-su evenly over the rice. Toss the rice by gently cutting into it vertically with your rice paddle (or spatula), and then lifting the rice and turning it over. As you do this, fan the rice with a hand fan or piece of cardboard (or get someone to help you). Add more of the sushi-su and continue the cutting, folding, and fanning process. Fanning the rice facilitates quick cooling, which gelatinizes the surface of the rice and gives a glossy finish to the rice. Towards the end, taste the rice occasionally to decide how much of you sushi-su you want to add.
2. Cover the seasoned rice with a moist cloth or plastic wrap until ready to use.