Shirakawago Soba

Begin preparing the dashi: Place 1000 grams of water and 10 grams of kombu in a medium pot. Let the kombu soak in the water for at least 15 minutes, or ideally 30 minutes, to extract its umami.

Gently heat the pot over medium-low heat. Just before the water comes to a boil, remove the kombu to prevent bitterness.

Bring the water to a rolling boil, then remove the pot from the heat. Immediately add 20 grams of katsuobushi to the hot water. Let the katsuobushi steep for 30 seconds to 1 minute, allowing its flavor to infuse.