Sumeshi (Seasoned Sushi Rice)

For the Sushi Vinegar: In a stainless-steel bowl, whisk together the rice vinegar, salt, and sugar. Pour the solution into a nonreactive, airtight container and add kombu, making sure it is fully submerged. Allow kombu to infuse at room temperature for 24 hours.

For the Rice: The next day, place rice in a large bowl and add enough cold water to cover. Using your fingers, gently massage and swish the grains in a circular motion until the water turns cloudy, about 30 seconds. Drain through a fine-mesh strainer, then refill the bowl with fresh water and repeat rinsing and draining until the water runs clear.

Transfer rice to the fine-mesh strainer and set it atop the bowl used to rinse the rice. Run the rice under cold water for 2 to 3 minutes, allowing the bowl to overflow and spill over. Lightly agitate the rice as the water continues to run, which should help to filter out any small shards of broken rice grains (these can make sushi rice sticky/gummy if not removed, even if the rice is otherwise correctly cooked).

Turn off the water and empty the bowl. Allow the rice to drain and air dry in the strainer for 10 minutes with the empty bowl beneath to catch any excess water.

If using a rice cooker, add the rice and filtered water to the pot of a rice cooker and, using your fingers, evenly disperse the grains. If your cooker has a “sushi rice” setting, set it to that and cook. Otherwise use the standard white rice setting.

If cooking rice on the stove-top, place the rice and filtered water in a 2- to 3-quart heavy-bottomed pot and give the pot a good shake to level the rice. Bring to a boil over medium-high heat, lower to a gentle simmer, then cover and cook until water is fully absorbed, about 12 minutes. Remove from the heat and allow the rice to steam, covered, for an additional 10 minutes.

Measure 3 tablespoons plus 1 teaspoon (50ml) sushi vinegar. Transfer hot rice into a wide, non-reactive container, such as a traditional wooden sushi oke/hangiri or 9-by 13-inch glass or ceramic baking dish; make sure not to transfer any crusty rice from the cooking pot (you can save this rice to be eaten separately, but it will ruin the sushi rice if not removed).

Hold a rice paddle or wooden spoon at a 45º angle above the rice. Slowly add the measured amount of sushi vinegar directly onto the paddle while waving the paddle back and forth to scatter and evenly distribute the vinegar onto the hot rice. Using long, sweeping strokes, smooth the rice into a flat even layer, gently breaking up any clumps as you go.

Once the rice is flat and all of the large clumps have been separated, push the rice into a pile on the side of the container nearest to you. Scoop the rice in small clusters, about the size of your paddle, and flip them towards the empty side of the container. Using swift cutting motions, gently break up the flipped clusters with your paddle as you go, specifically looking for small rice clumps. (These smaller clumps are unseasoned; separating and flipping the rice ensures each grain gets seasoned.) Continue this process until all of the grains have been separated and the rice is once again in a flat, even layer.

Rest the rice for 4 minutes. Using the paddle, flip the rice from top to bottom in small portions until all the rice has been flipped. Let rest an additional 2 minutes. This step ensures the seasoned vinegar is evenly distributed at all depths of the rice.

The rice is now ready to use. If you used a rice cooker, clean the pot, line it with a clean damp towel, transfer the rice back into it, and set the rice cooker to the “warm” setting. Otherwise, cover the rice in the pot with a damp towel to prevent it from cooling too quickly and drying out. Use sushi rice as desired, preferably while still slightly warm.