1 cup Japanese sushi rice
piece of kombu, wiped with a damp cloth (optional)
¼ cup rice vinegar
2½ tbsp sugar
1 tsp sea salt
Place the rice in a large bowl. Cover with water. Use your hands to stir and rub the rice in the water. Drain. Complete this process 6 more times or until the water runs (nearly) clear and is no longer “milky”. Some sushi chefs may do this up to 9 times. Drain well.
Transfer the rice to a medium saucepan. Cover with the 1½ cups of water (or use the amount specified by your sushi rice packet) and add the kombu if using.
Place the saucepan over high heat. Bring to a boil, then reduce heat to low, cover and cook for 10 minutes. Remove from heat and set aside, still covered, for 10 minutes to allow the steam to continue to cook the rice.
Meanwhile, make the seasoned vinegar. Place the ingredients in a small saucepan over medium heat. Cook, stirring, for 1-2 minutes or until the sugar has dissolved. Set aside until required.
Transfer the rice to a large shallow bowl or tray (traditionally a low-sided wooden bowl known as a sushi-oke or hangiri is used). Drizzle over the vinegar mixture. Use a rice paddle (shamozi) or spatula to fold the vinegar into the rice using a cutting action at an angle, breaking up any clumps and ensuring the vinegar mixture coats every grain of rice. Continue until the rice is at room temperature. Cover with a damp tea towel until ready to use.